PEDESTRIAN SUSPENSION BRIDGE PROJECT”

LAKE FOREST LAND FOUNDATION

Supplemental Specifications (Special Provisions)

For the

PEDESTRIAN SUSPENSION “BRIDGE PROJECT”

over the

NO-NAME RAVINE

March 8, 2021

Prepared for:

Penn Trails, LLC

Prepared by:

Chase Engineering, LLC

3626 Magnolia Drive

Easton, PA 18045

908-295-7732

[email protected]

Contact: Peter Chase

THE CONSTRUCTION MUST BE PERFORMED IN ACCORDANCE WITH THESE PROJECT SPECIFICATIONS. ERRORS AND/OR OMISSIONS SHALL BE BROUGHT TO THE ATTENTION OF THE OWNER'S REPRESENTATIVE. CHASE ENGINEERING WILL NOT HAVE CONTROL OF, NOR BE RESPONSIBLE FOR, THE CONSTRUCTION MEANS, METHODS, PROCEDURES, OR SAFETY PRECAUTIONS IN CONNECTION WITH

THE PROPOSED WORK. CONTRACTOR SHALL VERIFY ALL DIMENSIONS AND EXISTING CONDITIONS BEFORE ORDERING MATERIALS OR BEGINNING WORK. THIS DOCUMENT IS THE PROPERTY OF CHASE ENGINEERING, LLC. ANY USE OF A COPY THAT DOES NOT CONTAIN AN ORIGINAL RED OR CRIMPED SEAL IS STRICTLY PROHIBITED. THIS DOCUMENT IS NOT PUBLISHED AND ALL RIGHTS ARE RESERVED BY

CHASE ENGINEERING, LLC.

Penn Trails March 8, 2021

Lake Forest Land Foundation Pedestrian Suspension Bridge

Chase Engineering, LLC Page 2 of 44 Special Provisions: Table of Contents

TABLE OF CONTENTS

TABLE OF CONTENTS .................................................................................................................. 2

SUMMARY OF WORK ..................................................................................................................... 3

GENERAL ........................................................................................................................................... 4

MOBILIZATION ............................................................................................................................... 7

EXCAVATION AND BACKFILL ................................................................................................. 9

PIPE UNDERDRAINS FOR STRUCTURES 4”....................................................................... 11

YEAR MARKER ............................................................................................................................... 12

DECKING ......................................................................................................................................... 13

HELICAL PILES .............................................................................................................................. 15

MAIN CABLE SYSTEM, SUSPENDERS, AND BRACING CABLES ................................ 28

PROTECTIVE SEALER ................................................................................................................. 37

HANDRAIL ....................................................................................................................................... 41

END GATES ..................................................................................................................................... 43

APPENDIX 1 – GEOTECHNICAL REPORT AND SOIL BORING LOGS ................... 44



Chase Engineering, LLC Page 3 of 44 Special Provisions: Summary of Work

SUMMARY OF WORK

The scope of work is to construct a new pedestrian suspension bridge for the Lake Forest Open Lands Association Trail Project, located in Lake Forest, Illinois. The overall Project consists of approximately 2500 feet of natural aggregate stone surface trail, bridge, and trail head construction.

The bridge incorporates the 2013 ABA Outdoor Developed Areas Accessibility Guidelines as best management practices in design and construction. The main elements of the suspension bridge include wire rope, helical piles, structural steel, and reinforced concrete, as well as stone aggregate and prefabricated decking, as shown on the Plans.

The bridge components shall connect to the surface trail at the locations specified in the project drawings. The bridge, which crosses the No-Name Ravine, must be aligned and installed to the approved plans and specifications. Any existing condition that requires deviation from the corridor as shown on the project drawings will require the Contractor to notify the Owner and Owner’s Representative prior to construction. All work, unless specified otherwise by these Supplemental Specifications or the Project Drawings, shall be in accordance with the Illinois Standard Specifications for Road and Bridge Construction and other provisions of this contract.

In summary, the Bridge Project shall include but not be limited to the following:

1. Providing temporary access pathway(s) to the site of the bridge. 2. Construction of the bridge – including all materials, equipment, and labor to install the

bridge as required by the Project Plans, Standard Specifications, and Special Provisions. 3. Restoring the bridge site to the final grades. 4. Removal of the temporary access pathway(s). 5. Restoring the access pathway(s) to the original grades, if necessary.

END OF SECTION



Chase Engineering, LLC Page 4 of 44 Special Provisions: General

GENERAL

The bridge location is detailed on the Project Drawings contained within the “Lake Forest Open Lands Trail” plans sheets and the “Lake Forest Land Foundation – Pedestrian Bridge Over The No-Name Ravine” sheets B1 through B9.

All work shall be performed in accordance with the Plans, Standard Specifications, and these Special Provisions, unless superseded by the Owner’s Representative. It is anticipated that the conditions of the site at the time of construction might require modifications of the details shown on these construction drawings, or as specified herein. Any changes, either at the Contractor’s request or as determined to accommodate the site conditions, shall be at the sole discretion of the Owner’s Representative and shall be approved by him/her in writing prior to incorporation into the Work.

Where so used herein, the following terms are to be taken to have the following meanings:

• “Bridge Project” shall be the construction of the suspension bridge in accordance with the Plans, Standard Specifications, Special Provisions, and References. “Bridge Project” may also be termed “Pedestrian Bridge” in other portions of the Contract/Bid Documents.

• “Contractor” shall be the bidding company selected to complete the construction of the suspension bridge, including all sub-contractors hired to complete the overall Bridge Project.

• “Owner’s Representative” shall be that person(s) designated by the Owner to have review responsibilities of the overall Bridge Project during construction. This person(s) shall not have control of, or responsibility for, any aspect of the work including safety. For the Bridge Project, “Owner’s Representative” is synonymous with “Engineer” if used in other portions of the Contract/Bid Documents or IDOT Standard Specifications.

• “Standard Specifications” shall mean the current editions of the Illinois Department of Transportation (IDOT) publication “Standard Specifications for Road and Bridge Construction” and shall include the “Supplemental Specifications and Recurring Special Provisions”, also produced by the IDOT.

• “Plans” shall mean the Project Bridge Plans (9 sheets), as prepared by Chase Engineering, dated March 8, 2021.

• “References” shall mean those documents providing information in addition to, without superseding, that provided by the Plans, Specifications, or the Owner’s Representative.




PAYMENT, SCHEDULE OF QUANTITIES, AND BID PRICES

The Bridge Project will be performed according to the information provided in the Plans, Standard Specifications, Special Provisions, and “Lake Forest Land Foundation Specification for McCormick Ravine Public Access and Trails Design at Jean and John Greene Nature Preserve” (Project Specifications). Payment for the bridge work will be “Unit Price Work” as described in General Conditions Article 11.03 of the Project Specifications. IDOT Standard Specifications shall control any aspects of the work of the Bridge Project not covered in the Project Specifications.

The quantities appearing in the bid schedule for the Bridge Project are approximate and are prepared for the comparison of bids. Payment to the Contractor will be made only for the actual quantities of work performed and accepted or materials furnished according to the Contract. The scheduled quantities of work to be done and materials to be furnished may be increased, decreased, or omitted as hereinafter provided. Pay item quantities shall be adjusted to reflect the actual quantities in the final construction.

Submission of a bid shall be conclusive assurance and warranty the bidder has examined the plans and understands all requirements for the performance of the work. The bidder will be responsible for all errors in the proposal resulting from failure or neglect to conduct an in-depth examination. The Awarding Authority will in no case be responsible for any costs, expenses, losses, or changes in anticipated profits resulting from such failure or neglect of the bidder. The bidder shall take no advantage of any error or omission in the proposal and advertised contract.

PROTECTION AND RESTORATION OF PROPERTY

The Contractor shall protect and restore property according to Article 107.20 of the Standard Specifications and the following:

Trees and Shrubs: Extra care shall be exercised when operating equipment around trees or shrubs. Injured branches or roots hall be pruned in a manner satisfactory to the Owner’s Representative and shall be painted where the cut was made. Roots exposed during excavating operations shall be neatly pruned and covered with topsoil. This work shall be done as soon as possible and shall be considered as incidental to the contract, and no additional compensation will be allowed.

PROJECT SITE

The Contractor shall be provided a staging area in or near the existing parking lot, by Sheridan Road for their use, including vehicle parking, job trailer, equipment storage, and material storage as directed and coordinated by the Owner’s Representative. The staging area is not secure, and the Contractor shall provide their own means of securing any vehicles, materials, and/or equipment throughout the duration of construction.




The bridge site is located approximately 2,500 to 3,000 feet from the staging area. The Contractor shall construct a temporary access pathway between the bridge site and the staging area to minimize disturbance to the existing site. Due to the sensitive nature of the area, the Contractor shall use the smallest equipment possible to construct the bridge and to minimize disturbance to the site. The Contractor may construct a second access pathway to transport equipment and materials to the other side of the ravine, or provided temporary measures, approved by the Owner’s Representative, to transport equipment and materials to both ends of the bridge from one side of the ravine. The location(s) and materials used for the access pathway(s) shall be approved by the Owner’s Representative.

Contractor shall familiarize themselves with the requirements of the Bridge Project prior to bidding on this project, including the requirements for construction, breakdown of quantities and payment, location of the bridge site, staging area location, and possible access routes between the two locations.

LIMITS OF OPERATIONS

The bridge structures are located in a wooded preserve, near a residential area in The City of Lake Forest. The Contractor shall limit his work operations to the daylight hours of 7 a.m. to 8 p.m., on weekdays, to minimize noise disruption to surrounding residences. Work on Saturdays and legal holidays will be permitted only if permission is obtained from the Owner’s Representative and the City Engineer and work hours shall be from 8 a.m. to 6 p.m.

END OF SECTION



Chase Engineering, LLC Page 7 of 44 Special Provisions: Mobilization

MOBILIZATION

This item shall conform to the requirements of Section 671 of the Standard Specifications except as modified herein.

GENERAL

In addition to the items listed in Section 671 of the Standard Specifications, the MOBILIZATION pay item shall also include:

• Providing an access pathway from the Contractor’s staging area for the transport of all materials, tools, equipment, and personnel to and from the bridge site. This shall be achieved using timber mats, or other methods approved by the Owner’s Representative, and shall minimize the disturbance to the surrounding site. Depending on the Contractor’s methods of construction, two access pathways may be required, one to each side of the ravine. Location of the pathway(s) and construction material(s) shall be approved by the Owner’s Representative.

• Providing temporary erosion and sediment control systems at the bridge site and along the access pathway(s) in accordance with Section 280 of the Standard Specifications.

• Removal of the materials used for the access pathway(s) and restoring site to the site along the pathway(s) to the original grades using native topsoils from the project site or other materials approved by the Owner’s Representative.

• Conformance to the permit requirements for this project, including:

o United States Army Corps of Engineers (USACE)

o Illinois Department of Natural Resources (IDNR)

o Lake County Stormwater Management Commission

o The City of Lake Forest

• Cutting/felling of trees identified to be removed, and the clearing of brush and small trees within the designed bridge corridor or as needed to accomplish the construction noted on the Plans. Removal and disturbance to trees and shrubs shall be kept to a minimum.

• Protection of trees to remain at the bridge site in accordance with Sections 201 and 202.02 of the Standard Specifications.

• Services of a Licensed Surveyor and Geotechnical Engineer, as required in the Special Provisions, hired as a sub-contractor by the Contractor. Specifically, these services include:

o Surveying to finalize the existing site elevations and to coordinate the final bridge layout with the Owner’s Representative.



Chase Engineering, LLC Page 8 of 44 Special Provisions: Mobilization

o Surveying as needed throughout construction, including, but not limited to, determination of excavation depths, setting elevations for concrete structures, helical pile end caps, cable layout, cable placement, determination of cable sag and deck camber, and setting final grades.

o Geotechnical testing for determination of soil bearing capacity during excavation at the level of each abutment footing.

o Geotechnical testing of compaction during backfilling operations.

• Any other cost for labor, equipment, and materials, not covered in another pay item, needed for completion of the Bridge Project.

END OF SECTION



Chase Engineering, LLC Page 9 of 44 Special Provisions: Excavation and Backfill

EXCAVATION AND BACKFILL

These items shall conform to the Standard Specifications, including, but not limited to, Sections 202, 209, 502, except as modified herein.

DESCRIPTION

This work shall consist of:

• Excavation at each end of the bridge to construct the abutments.

• Furnishing, placement, and compaction of the foundation stone below the footings.

• Furnishing, placement and compaction of the porous granular backfill behind each abutment wall.

• Backfilling and compaction of the excavated soils to the final grades.

• Removal and disposal of excavated soils in excess of the quantity needed for backfilling to final grades and/or unsuitable materials.

GENERAL

Prior to any excavation, a surveyor Licensed in the state of Illinois shall be retained by the contractor to perform a limited survey of the bridge site to determine existing ground elevations. In addition, the layout of the structure, including the abutments and location of cable anchors, will be staked for final approval by the Owner’s Representative.

For the purposes of quantities shown on the bridge plans, the limits of excavation extend horizontally two feet on each side of the concrete footing. The depth of the footing is assumed to be 10 ft-3 in. below grade. The actual depth of the footing will be as needed to achieve a net soil bearing capacity of 4,000 pounds per square foot (not including the weight of the overburden). The minimum depth of the excavation shall be 9 ft-3 in. and shall be determined based on the soil testing at that depth. The Contractor shall retain a geotechnical engineer for soils testing during excavation. The soils testing geotechnical reports shall be sealed by a Professional Engineer licensed in Illinois. All excavations shall meet the requirements of the Contractor’s safety plan, IDOT, and the Occupational Safety & Health Administration (OSHA).

“Foundation Stone” below each abutment shall be installed subject to the notes on the Bridge Plans if required by the Owner’s Representative. The need for crushed stone below the concrete abutment shall be based on the results of the soils testing performed during construction.

Filter Fabric shall consist of “Fabric for Ground Stabilization”, as described in Section 210. The filter fabric shall be placed on all sides (top, bottom, and sides) of the porous granular backfill, and the foundation stone if required.



Chase Engineering, LLC Page 10 of 44 Special Provisions: Excavation and Backfill

Excavated soils shall be used to backfill the abutment above the porous granular backfill. A geotechnical engineer shall perform soils testing during placement and compaction for quality control purposes. The geotechnical reports shall be sealed by a Professional Engineer licensed in Illinois. Final grades will be determined by the Owner’s Representative during construction. On the backspan side of the abutment, the final grades of the backfill will transition to the existing grades. On the ravine side of each abutment, the final grades for the backfill shall transition the existing grades to an elevation that is approximately 1 ft-6 in. below the bearing seat for the superstructure.

Excavated soils and materials not suitable for backfill shall be removed from the project site and disposed in accordance with Section 202 of the Standard Specifications.

MATERIALS

If required, the foundation stone below each abutment shall be gradation CA7 and conform to Section 1004 of the Standard Specifications.

Porous granular backfill behind each abutment wall shall be gradation CA7 and conform to Section 1004 of the Standard Specifications.

For Filter Fabric, see the requirements of Section 210 of the Standard Specifications.

BASIS OF PAYMENT

Soil excavation for the construction of the abutments, including trench boxes or other temporary stabilization measures, will not be paid separately and all costs shall be incidental to the CONCRETE STRUCTURES pay item.

Foundation stone below each abutment, if required, and the porous backfill on the sides of the footing and to the height shown on the plans will be paid for at the contract price per cubic yard for POROUS GRANULAR BACKFILL.

Filter fabric on the perimeter (top, bottom, and sides) of the foundation stone and porous granular backfill shall not be paid separately and all costs shall be incidental to the POROUS GRANULAR BACKFILL pay item.

Placement and compaction of the excavated soils on the ravine side of the abutment and above the porous granular backfill on the backspan side of the abutment will not be paid separately. The cost of this work shall be incidental to the CONCRETE STRUCTURES pay item.

Excavated soils in excess of that needed for backfill and materials not suitable for backfill shall be removed and disposed at the contract unit price per cubic yard for REMOVAL AND DISPOSAL OF UNSUITABLE MATERIAL.

Subcontractor services, including a Licensed Surveyor and a Geotechnical Engineer, will not be paid separately and costs shall be incidental to the MOBILIZATION pay item.

END OF SECTION



Chase Engineering, LLC Page 11 of 44 Special Provisions: Pipe Underdrains

PIPE UNDERDRAINS FOR STRUCTURES 4”

Work under this item shall be performed according to the Standard Specifications, including but not limited to, Section 601, Guide Bridge Special Provision Check Sheet #51 (dated October 23, 2020) for PIPE UNDERDRAINS FOR STRUCTURES for the size specified, and the Bureau of Design and Environment (BDE) Check Sheet (dated November 1, 2019) for GEOTECHNICAL FABRIC FOR PIPE UNDERDRAINS AND FRENCH DRAINS (BDE).

END OF SECTION



Chase Engineering, LLC Page 12 of 44 Special Provisions: Year Marker

YEAR MARKER

DESCRIPTION

Furnish, fabricate, transport, and install Bronze year marker, inscribed with text as directed by Owner’s Representative or as shown on Plans.

GENERAL

Before starting work, the Contractor shall submit, for the approval of the Owner’s Representative, samples of materials and finishes together with the chemical composition of the year marker.

The text shown on the Plans is subject to change. Upon confirmation of the text, the Contractor shall submit a full-sized shop drawing of the marker showing size and arrangement of letters for the approval of the Owner’s Representative prior to casting the marker. Block letters shall be used. None other than a company of established reputation in the making of art metalwork will be approved as a subcontractor for this work.

Year Marker shall be installed and accepted by the Owner’s Representative, for all material, labor, and equipment necessary to complete the work.

Work not specified herein shall conform to Section 515 of the Standard Specifications.

MATERIALS

The plaque shall be cast in one piece of statuary bronze. Background shall be in dark oxidized hard matted surface having a stippled appearance; borders and tops of letters to have a smooth, burnished finish at location as shown on the Plans.

The Plaque shall conform to a size and style as shown on the Plans and as approved by the Owner’s Representative and shall be raised 3/32 inch from the surface of the marker.

CONSTRUCTION

The year marker shall be installed in the formwork prior to placing the concrete.

The year marker is to be installed at locations shown on the Plans.

MEASUREMENT AND PAYMENT

Year Marker shall be paid for at the contract unit price per each for YEAR MARKER. Payment shall constitute full compensation for fabricating, furnishing, and installing all components, and for all labor, equipment, tools, and incidentals to complete the work.

END OF SECTION



Chase Engineering, LLC Page 13 of 44 Special Provisions: Decking

DECKING

DESCRIPTION

This work shall include the provision and installation of all decking, including attachment to stringers, in accordance with the Plans.

GENERAL

Deck shall be composed prefabricated panels, configured and installed in accordance with the Plans.

Decking material shall weigh between 5 pounds per square foot (minimum) and 10 pounds per square foot (maximum).

Minimum thickness for the decking material is 1-1/2 inches. Thicker decking shall require adjustment to the guardrail height and suspender lengths to meet the guardrail dimensions shown on the Plans.

Deck surface shall be non-skid, with a minimum dynamic coefficient of friction of 0.60.

Decking shall be “maintenance-free” material, such as composite boards, fiber reinforced polymer, or other system approved by the Owner’s Representative.

Decking and attachment system shall be capable of resisting the following working (unfactored) loads:

• 90 pounds per square foot uniform load.

• 300-pound point load applied over 4 square inches.

• 1,500-pound point load applied over 1.0 square foot.

• 35 pounds per square foot uplift force.

• 50 pounds per foot lateral force.

Submittal requirements:

• Proposed decking material with Manufacturer’s specifications.

• Shop drawings showing the limits of the decking / deck panels.

• Cutting and/or fabrication methods used to obtain the dimensions shown on the Plans.

• Attachment methods to the structural steel.

• Calculations to demonstrate the adequacy of the decking material and attachments to meet the required loadings.

• Details to accommodate thermal expansion and contraction.

• Required adjustments to the bridge elevations and/or suspender lengths to accommodate the selected deck thickness.



Chase Engineering, LLC Page 14 of 44 Special Provisions: Decking

MATERIALS

Material for the bridge deck shall be:

• Pedestrian Pultruded Fiberglass Grating, manufactured by Canadian Composite Structures, Inc.

• Safe-T-Span Pultruded Grating manufactured by Fibergrate Composite Structures.

• Other equivalent bridge deck system approved by the Owner’s Representative.

CONSTRUCTION

Installation of the bridge decking / deck panels, including attachment to the structural steel, shall be as recommended by the Manufacturer and approved by the Owner’s Representative.


Measurement shall be taken from out to out in width of installed and accepted decking, and as measured between the front faces of each abutment backwall. There shall be no subtraction for open joints. Item shall include the decking complete and in-place, including attachment to stringers, as accepted by the Owner’s Representative, including all equipment, labor, materials, and incidentals needed to complete the work. Payment will be at the contract unit price per square foot for DECKING. Payment shall constitute full compensation for fabricating, furnishing, and installing all components, and for all labor, equipment, tools, and incidentals to complete the work.

END OF SECTION



Chase Engineering, LLC Page 15 of 44 Special Provisions: Helical Piles

HELICAL PILES

DESCRIPTION

This work shall consist of the design, furnishing, fabrication, transport, and installation of four helical piles and attachments for the cable anchorages at locations as indicated on Plans. This work shall include testing of each installation to 133% of the specified maximum load, as indicated on the Plans. All work shall be done in accordance with the requirements of the manufacturer/installer, and with the requirements of the Post-Tensioning Institute, as described in their “Recommendations for Prestressed Rock and Soil Anchors”, as applicable

The helical pile drawing shown on the Plans are for reference only. The helical pile type, size, connections, length, and installation torque shall be established by the Pile Design Professional and shall be based on the loads provided on the Plans.

The original “Subsurface Exploration and Geotechnical Engineering Report” by GEI Consultants, dated January 29, 2019, which includes soil boring logs, is attached in Appendix 1. The contractor shall perform additional soil borings as necessary to determine the adequacy of the piles based on the requirements shown on the Plans and in these Special Provisions.

GENERAL

DEFINITIONS:

Helical Pile – Manufactured steel foundation with one or more helical bearing plates that is rotated/torqued into the soil until the lead section is embedded into a load bearing stratum. In the final installed condition, the helical piles transfer tension from the main cables to a load bearing stratum.

Lead Section – The first section of a helical pile to enter the ground. Lead Sections consist of a central shaft with a tapered end and one or more helical bearing plates affixed to the shaft.

Extension Section – Helical pile or sections that follow the Lead Section into the ground and extend the lead section to the necessary depth. Extension sections consist of a central shaft and may have helical bearing plates affixed to the shaft. Each extension is connected with integral couplings which provide a rigid load transferring connection.

Cap Plate – Helical pile termination device that is bolted or welded to the end of the helical pile after completion of installation to facilitate attachment of the main cable.

Augering – Rotation of the shaft with little or no advancement. It can occur when the helical bearing plates pass from a relatively soft material into a comparatively hard material. Augering can also result from insufficient crowd or downward pressure during installation. In some cases, augering may be (temporarily) necessary in order to grind through an obstruction.




Pile Design Professional – Individual or firm responsible for the design of the helical piles.

Bearing Stratum – The undisturbed soil layer at any pile excavation location which provides a significant portion of the axial resistance of an installed helical pile bearing on one or more of the pile helices.

Helical Pile Contractor - The person/firm responsible for performing the helical pile work, including fabrication and installation.

Crowd – Axial compressive force applied to the head (top) of the helical pile shaft during installation as required to ensure the pile progresses into the ground with each revolution a distance approximately equal to the helix pitch.

Helix Driver – A high torque hydraulic motor used to advance (screw) a helical pile into the soil to a load bearing stratum.

Helix Plate – A round plate formed into a ramped spiral. When rotated into the soil, the helical shape provides thrust along its longitudinal axis thus aiding in pile installation. After installation, the plate transfers axial load into the soil through bearing.

Installation Torque – The resistance generated by a helical pile when installed into the soil. The installation resistance is a function of the strength properties of the soil the helical piles are being installed in as well as the shaft geometry of the pile shaft and helical plates.

Torque Rating – The maximum torque energy that can be applied to a helical pile during installation into the soil.

REFERENCES

The current edition of the following references shall be considered, as appropriate:

American Association of State Highway and Transportation Officials (AASHTO)

AASHTO LRFD Bridge Design Specifications, 8th Edition

American Institute of Steel Construction (AISC)

ANSI/AISC 360 Specification for Structural Steel Buildings

American Society of Testing and Materials (ASTM)

ASTM A29 Standard Specification for General Requirements for Steel Bars, Carbon and Alloy, Hot Wrought

ASTM A709 Standard Specification for Structural Steel for Bridges




ASTM A53 Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless

ASTM A123 Standard Specification for Zinc (Hot-Dip Galvanized) Coatings on Iron and Steel Products

ASTM A153 Standard Specification for Zinc Coating (Hot Dip) on Iron and Steel Hardware

ASTM A450 Standard Specification for General Requirements for Carbon and Low Alloy Steel Tubes

ASTM D3689 Standard Test Method for Deep Foundations Under Static Axial Tensile Load

ASTM A500 Standard Specification for Cold Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes

ASTM F3125 Standard Specification for High Strength Structural Bolts and Assemblies, Steel and Alloy Steel, Heat Treated, Inch Dimensions 120 ksi and 150 ksi Minimum Tensile Strength

ASTM 563 Standard Specification for Carbon and Alloy Steel Nuts

American Welding Society (AWS)

AWS D1.5 Bridge Welding Code

AWS B2.1 Specification for Welding Procedure and Performance Qualification

International Code Council - Evaluation Services (ICC-ES)

Acceptance Criteria for Helical Pile Systems and Devices (AC358)

Evaluation Service Report (ESR)

International Organization for Standardization (ISO)

ISO 9001:2008 – Quality Management System

Post-Tensioning Institute

Recommendations for Prestressed Rock and Soil Anchors




QUALIFICATIONS

Helical Pile Contractor:

The fabrication and installation of the helical piles shall be performed by:

• CYNTECH (A Keller Company), (936) 206-7810, www.cyntech.com.

• Qualified Helical Pile Contractor approved by the Owner’s Representative:

o Helical piles shall be fabricated by an organization specializing in the manufacturing and distribution of these products, with fabrication of at least 100 helical piles on no less than five (5) similar projects over the last five (5) years.

o Helical piles shall be installed by an organization specializing in the installation of at least 100 helical piles on no less than five (5) similar projects over the last five (5) years.

Pile Design Professional:

The design of the helical pile shall be performed by a Licensed Structural Engineer in the State of Illinois with at least five (5) years of experience related to the design of helical pile foundations. Pile design professional shall demonstrate similar design work on at least ten (10) projects over the past five (5) years.

The qualifications list for organizations and personnel shall be submitted for approval prior to design, shop drawing submittals, and fabrication of the helical piles.

SUBMITTALS

Prior to fabrication and installation of the helical piles, the following shall be submitted for review and approval by the Owner’s Representative.

1. Helical Pile Contractor and Pile Design Professional qualifications

2. Product Data

3. Design Calculations: Submittal shall include the design of the helical piles. Design shall utilize the total cable force on the Plans and a minimum factor of safety (FS) of 3.0. Calculations shall be in accordance with AASHTO LRFD Bridge Design Specifications. For limit states not covered in AASHTO, AISC 360 shall be used. All calculations shall be signed and sealed by a Licensed Structural Engineer in the State of Illinois. Submittal calculations shall include, but are not limited to:




a. Calculations for strength of the helical pile plate, shaft, and connections.

b. Consideration of pile capacity with maximum permissible eccentricities due to the installation angle tolerances.

c. Minimum installation depth necessary to reach the bearing stratum and installation depth necessary to achieve the required capacity.

d. Calculations for pile capacity based on the soil profile, pullout capacity, and installation length. At least the top five (5) feet of soil shall be neglected for strength.

e. Calculations for a 75-year design life. Shaft dimensions, element thicknesses, and connections shall include sacrificial thickness or a higher factor of safety based on anticipated corrosion loss over the design life for project soil conditions.

f. Considerations for downdrag, buckling, and expansive soils (as appropriate)

g. Termination criteria

h. Estimated pile cap plate movement at design loads.

4. Shop Drawings: The Helical Pile Contractor shall submit shop drawings for all helical pile components, including corrosion protection and cable attachment to the Owner for review and approval. Submittal shall indicate product chosen and provide details of assembly and installation. The Helical Pile Contractor or Pile Design Professional shall prepare and submit to the Owner, for review and approval, working drawings and design calculations for the helical piles intended for use at least 14 calendar days prior to planned start of fabrication. Helical pile shop drawing submittal shall include, but is not limited to:

a. Product identification number(s) and designation(s)

b. Maximum allowable mechanical tensile strength of the helical piles

c. Planned installation depth and the number of lead and extension sections.

d. Number and diameter of helical bearing plates.

e. Manufacturer’s recommended capacity to installation torque ratio.

f. Minimum final installation torque(s).

g. Corrosion protection coating on helical piles.

h. Elevation of the helical pile cap plate connection to meet specified tolerances and to meet the design length of the main cable system.

5. The Helical Pile Contractor shall submit a detailed description of the construction procedures proposed for use to the Owner for review. This shall include a list of major equipment to be used, installation procedure, and proposed documentation.




Calibration information certified by an independent testing agency for the torque measurement device and all load testing and monitoring equipment to be used on the project shall also be submitted. Calibration information shall have been tested within the last year of the date submitted. Calibration information shall include, but is not limited to, the name of the testing agency, identification number or serial number of device calibrated, and the date of calibration.

6. The Helical Pile Contractor shall submit a proposed load testing plan in accordance with ASTM D3689, including, but not limited to, testing method, equipment, load rate, and testing agency (if used).

7. The Working Drawings for use on site shall include the following:

a. Helical pile number, location, and pattern by assigned identification number.

b. Helical pile design load.

c. Type and size of central steel shaft.

d. Minimum effective installation torque.

e. Minimum overall length.

f. Inclination and orientation of helical pile.

g. Final cap plate elevation.

8. Installation records: The Contractor shall provide the Owner’s Representative copies of installation records within 48 hours after each installation is completed. These installation records shall include, but are not limited to, the following information:

a. Name of project and Helical Pile Contractor.

b. Name of Helical Pile Contractor’s supervisor during installation.

c. Date and time of installation.

d. Name and model of installation equipment

e. Type of torque indicator used.

f. Location of helical pile by grid location, diagram, or assigned identification number.

g. Type and configuration of lead section with length of shaft and number and size of helical bearing plates.

h. Type and configuration of extension sections with length and number and size of helical bearing plates, if any.

i. Installation duration and observations.

j. Total length installed.




k. Final elevation of cap plate.

l. Final inclination of shaft.

m. Installation torque at minimum three-foot depth intervals.

n. Final installation torque.

o. Comments pertaining to interruptions, obstructions, augering, or other relevant information.

p. Results of the load test on each pile.

QUALITY ASSURANCE

The Helical Pile Contractor shall employ an adequate number of skilled workers who are experienced in the necessary crafts and who are familiar with the specified requirements and methods needed for proper performance of the work of this specification.

All helical piles shall be installed in the presence of a designated representative of the Owner unless said representative informs the Contractor otherwise. The designated representative shall have the right of access to all field installation records and test reports. In the event of conflict between the plans and approved pile design documentation, the Helical Pile Contractor shall not begin construction on any affected items until such conflict has been resolved.

Helical pile components as specified therein shall be manufactured by a facility whose quality systems comply with ISO (International Organization of Standards) 9001 requirements. Certificates of Registration denoting ISO Standards Number shall be presented upon request to the Owner or their representative.

Chosen product shall provide a minimum one-year warranty on materials and workmanship of the product from the date of installation.

SITE CONDITIONS

Only limited soils investigations have been made at the site, and the soil borings are included in Appendix 1. The Contractor is to conduct additional examination and testing of the project site, if necessary, to determine the adequacy of the soils and that the proposed anchor installations meet the needs of the Project.

CLOSEOUT SUBMITTALS

Warranty: Project Warranty including Manufacturer’s Warranty.

Accurately record actual locations of materials used in finished construction.




MATERIALS

Helical piles shall conform to the requirements of the manufacturer, as well as the recommendations of the Post-Tensioning Institute.

Material for the helical piles shall be as specified by the Pile Design Professional and approved by the Owner’s Representative.

Bolts for connections shall be AASHTO M164 (ASTM F3125 Grade A325).

Helical piles and all metal hardware are to be hot-dipped galvanized in accordance with ASTM A123 or ASTM A153, as appropriate.

All helical pile connections shall have a minimum of three bolts or shop-installed welds. No field welding shall be permitted.

Helical piles shall be designed to meet the specified loads shown on the Plans with a factor of safety of 3.0 or greater. The calculations and drawings required from the Pile Design Professional shall be submitted to the Owner’s Representative for review and acceptance.

CONSTRUCTION

GENERAL

1. The Helical Pile Contractor shall not sublet the whole or any part of the contract without the express written permission of the Owner.

2. The Helical Pile Contractor shall review site soil conditions and present written certification, attested by a responsible person experienced in the evaluation of soil conditions, that the site anticipated for the helical piles and the installation methods chosen are compatible with the design requirements shown on the Plans and in these Special Provisions.

3. The Helical Pile Contractor shall provide calculations prepared by the Pile Design Professional related to the capacity for uplift and direct load, showing that the selected installation meets or exceeds the requirements of the loads indicated on the Plans, and will not exceed the capacity of the actual site conditions. The Pile Design Professional shall be responsible for interpreting the soil boring data in Appendix 1, and requesting additional soil borings from the Helical Pile Contractor, if required. Variations in geologic deposits, overburden materials, and ground water elevations may occur between borings and will not necessarily be considered a change in site conditions as defined by Article 104.03 of the Standard Specifications.




4. The Helical Pile Contractor shall be experienced in performing design and construction of helical piles and shall furnish all materials, labor, and supervision to perform the work. The Contractor shall be trained and certified by the manufacturer in the proper methods of design and installation of helical piles. The Contractor shall provide names of on-site personnel materially involved with the work, including those who carry documented certification from the manufacturer. At a minimum, these personnel shall include foreman, machine operator, and project engineer/manager.

5. Before entering the construction site to begin work, the Helical Pile Contractor shall provide proof of insurance coverage as stated in the general specification and/or the contract.

6. The Helical Pile Contractor shall request markings of underground utilities by an underground utility location service.

7. The Contractor shall conduct his construction operations in a manner to ensure the safety of persons and property in the vicinity of the work. The Helical Pile Contractor’s personnel shall comply with safety procedures in accordance with OSHA standards and any established project safety plan.

TOLERANCES

Helical piles shall be installed as close to the specified installation and orientation angles as possible. The installation of the helical piles shall be coordinated with the cable shop drawings such that the helical piles and main cable are fabricated to meet the requirements and tolerances for cable length, cable sag, and tower plumbness. Tolerances for the helical piles shall be as follows.

1. Centerline of helical pile shall not be more than 3 inches from indicated plan location.

2. Helical pile installation shall be within 2° of design alignment.

3. Top elevation of helical pile shall be within +1 inch to –2 inches of the design vertical elevation set by the Contractor to achieve the correct length and sag of the main cable. The elevation of the helical pile end cap above the finished grade shall be as directed by the Pile Design Professional.

SITE STORAGE

All Helical Pile and Bracket Assemblies shall be free of structural defects and protected from damage. Store Helical Piles and Bracket Assemblies on wood pallets or supports to keep from contacting the ground. Damage to materials shall be cause for rejection.




EXAMINATION

A. Helical Pile Contractor shall take reasonable effort to locate all utilities and structures above and underground in the area of the Work. Helical Pile Contractor shall pot hole to determine the exact location of underground utilities and buried structures within a distance from a helical pile equal to three times the maximum helix diameter. Helical Pile Contractor is responsible for protection of utilities and structures shown on the Plans. Costs of relocating utilities not shown on Plans shall be paid by Owner as extra work.

B. Helical Pile Contractor shall review Plans and the original subsurface investigation report to determine subsurface conditions for sizing and installation of helical piles. In addition, Helical Pile Contractor shall make a site visit to observe conditions prior to the start of Work. Contractor shall be responsible for the costs of additional borings if deemed necessary based on the review of the original subsurface investigation.

C. Helical Pile Contractor shall notify Engineer of any condition that would affect proper installation of helical piles immediately after the condition is revealed.

D. If excavation is required for proper installation of helical piles, Helical Pile Contractor shall make safe excavations in accordance with OSHA standards.

E. Contractor shall notify Engineer at least 24 hours prior to installation of helical piles.

INSTALLATION EQUIPMENT

A. Torque Motor: Helical Piles should be installed with high torque, low RPM torque motors, which allow the helical plates to advance with minimal soil disturbance. The torque motor shall be hydraulic power driven with clockwise and counter-clockwise rotation capability. The torque motor shall be adjustable with respect to revolutions per minute during installation. Percussion drilling equipment shall not be permitted. The torque motor shall have torque capacity equal to or greater than the minimum final installation torque required for the project. The connection between the torque motor and the installation rig shall have no more than two pivot hinges oriented 90 degrees from each other. Additional hinges promote wobbling and affect lateral capacity.

B. Installation Equipment: The installation equipment shall be capable of applying adequate crowd and torque simultaneously to ensure normal advancement of the helical piles. The equipment shall be capable of maintaining proper alignment and position.

C. Drive Tool: The connection between the torque motor and helical pile shall be in-line, straight, and rigid, and shall consist of a hexagonal, square, or round kelly bar adapter and helical shaft socket. To ensure proper fit, the drive tool shall be manufactured by the Helical Pile manufacturer and used in accordance with the manufacturer’s installation instructions.




D. Connection Pins: The central shaft of the helical pile shall be attached to the drive tool by ASME SAE Grade 8 smooth tapered pins matching the number and diameter of the specified shaft connection bolts. The connection pins should be maintained in good condition and safe to operate at all times. The pins should be regularly inspected for wear and deformation. Pins should be replaced with identical pins when worn or damaged.

E. Torque Indicator: A torque indicator shall be used to measure installation torque during installation. The torque indicator can be an integral part of the installation equipment or externally mounted in-line with the installation tooling. The torque indicator shall be capable of torque measurements with a sensitivity of 500 ft-lb or less. Torque indicators shall have been calibrated within 1-year prior to start of Work. Torque indicators that are an integral part of the installation equipment shall be calibrated on-site. Torque indicators that are mounted in line with the installation tooling shall be calibrated either on-site or at an appropriately equipped test facility. Indicators that measure torque as a function of hydraulic pressure shall be re-calibrated following any maintenance performed on the torque motor. Torque indicators shall be re-calibrated if, in the opinion of the Engineer, reasonable doubt exists as to the accuracy of the torque measurements.

INSTALLATION PROCEDURES

A. The number and size of helical blades shall be determined by the Helical Pile Contractor’s Pile Design Professional in order to achieve the required torque and tensile/bearing capacity for the soil conditions at the site. The ratio of design load to the total area of the helical bearing plates shall not exceed the allowable bearing capacity determined from the Pile Design Professional based on the soil borings.

B. Connect the lead section to the Torque Motor using the Drive Tool and Connection Pins. Position and align the Lead Section at the location and to the inclination shown on the Plans and crowd the pilot point into the soil. Advance the lead section and continue to add extension sections to achieve the Termination Criteria. All sections shall be advanced into the soil in a smooth, continuous manner at a rate of rotation between 5 and 25 revolutions per minute. Snug tight all coupling bolts.

C. Constant axial force (crowd) shall be applied while rotating helical piles into the ground. The crowd applied shall be sufficient to ensure that the helical pile advances into the ground a distance equal to at least 80% of the blade pitch per revolution during normal advancement. The rate of down pressure (crowd) shall be adjusted for different soil conditions and depths.

D. The manufacturer’s torsional strength rating of the helical pile shall not be exceeded during installation.




E. Bolt hole elongation due to torsion of the shaft of a helical pile at the drive tool shall be limited to 1/8 inch. Helical piles with bolt hole damage exceeding this criterion shall be uninstalled, removed, and discarded.

F. When the Termination Criteria of a helical pile is obtained, the Helical Pile Contractor shall adjust the elevation of the top end of the shaft to the elevation shown on the Plans or as required. This adjustment shall consist continuing the installation until the final elevation and orientation of the cap plate holes are in alignment. Contractor shall not reverse the direction of torque and back-out the helical pile to obtain the final elevation. Cutting off the top of the shaft and drilling new holes to facilitate installation of cap plate to the orientation shown on the Plans is not permitted without written acceptance of the Owner’s Representative.

G. The Contractor shall install the helical pile cap plates in accordance with the approved fabrication details.

TERMINATION CRITERIA

A. Helical Piles shall be advanced until all the following criteria are satisfied.

1. Axial capacity is verified by achieving the final installation torque as provided by the Pile Design Professional.

2. Minimum depth is obtained. The minimum depth shall be as shown on the Working Drawings, that which corresponds to the planned bearing stratum, or the depth at which the final installation torque is measured, whichever is greater.

B. If the torsional strength rating of the helical pile and/or the maximum torque of the installation equipment has been reached or augering occurs prior to achieving the minimum depth required, the Helical Pile Contractor shall have the following options:

1. Terminate the installation at the depth obtained subject to the review and acceptance of the Owner’s Representative.

2. Remove the helical pile and install a new one with fewer and/or smaller diameter helical bearing plates or with dual cutting edge helical bearing plates. The new helical configuration shall be subject to review and acceptance of the Owner’s Representative.

3. Remove the helical pile and pre-drill a 4-inch diameter pilot hole in the same location and reinstall the pile.

4. If the obstruction is shallow, remove the helical pile and remove the obstruction by surface excavation. Backfill and compact the resulting excavation and reinstall the pile.

5. Remove the helical pile and relocate 1-foot to either side of the installation location subject to the review and acceptance of Owner’s Representative.




6. The Helical Pile Contractor shall notify the Owner’s Representative if an obstruction is encountered. An obstruction is defined as an object (such as, but not limited to, boulders, logs, old foundations, etc.) that cannot be drilled through using normal casing advancement techniques. Upon concurrence of the Owner’s Representative, the Helical Pile Contractor shall begin working to core, break up, push aside, or remove the obstruction unless relocating the helical pile would be less expensive. For smaller obstructions reverse the direction of torque, back-out the helical pile a distance of 1 to 2 feet and attempt to reinstall by decreasing crowd and augering through the obstruction.

C. If the final installation torque is not achieved at the specified length, the Helical Pile Contractor shall have the following options:

1. Until the maximum depth is achieved (if any), install the helical pile deeper using additional extension sections.

2. Remove the helical pile and install a new one with additional and/or larger diameter helical bearing plates. The new helix plate configuration shall be subject to review and acceptance by the Owner’s Representative.

LOAD TESTING

A. Each helical pile shall be load tested in accordance with ASTM D3689.

B. All four (4) of the final installed anchors shall be load-tested to a minimum of the 133 percent of the anticipated design load at that location (as indicated on the Plans) for a hold time of not less than ten (10) minutes. Total anchor head movement shall be one-half inch (1/2”) or less.

C. The Helical Pile Contractor shall provide the Owner’s Representative copies of field test reports confirming helical pile configuration and construction details within 24 hours after completion of the load tests.


This pay item includes the design, fabrication, delivery, installation, and load testing of the helical piles up to the cap plate. No additional payment will be made for incidental items required for the helical piles. No additional payment will be made for testing, or replacement of anchors not meeting test specifications, or for all material, labor, and equipment necessary to complete the work. Each helical pile installed and approved by the Owner’s Representative will be paid at the contract unit price per each for FURNISH AND INSTALL SOIL ANCHORS. Payment shall constitute full compensation for fabricating, furnishing, and installing all components, and for all labor, equipment, tools, and incidentals to complete the work.

END OF SECTION



Chase Engineering, LLC Page 28 of 44 Special Provisions: Cable System

MAIN CABLE SYSTEM, SUSPENDERS, AND BRACING CABLES

DESCRIPTION

This work includes the installation of a cable system for the bridge superstructure, including:

• Main Cables for support of the superstructure including attachment to the helical pile end caps

• Suspender Cables for supporting the floor framing from the Main Cables

• Cables for Underdeck Bracing

• Hardware for inter-connection of cable elements and for attachment to anchorage systems, floorbeams, and tower pedestals

• Cable Saddles

Design has been in accordance with LRFD method, augmented with the Working Stress method. Cable suspension systems have been designed with a Factor of Safety of 3.0; Suspender Cables have been designed with a Factor of Safety of 5.0.

GENERAL


Contractor shall coordinate the lengths of the main cable, suspender cables, and the elevations of the helical pile cap plates in order to achieve the dimensions and tolerances specified on the Plans and in the Special Provisions. These systems work together and must be fabricated as such to meet the specified geometry.

SUBMITTALS

QUALIFICATIONS

The Contractor is responsible for final detail and design the cable connections. The main cable socket design shall be submitted to the Owner’s Representative for approval. Contractor shall submit the fabricator that will be making the main cable spelter socket and swaged suspender cable connections. This fabricator shall demonstrate knowledge with these connections and shall be approved by the Owner’s Representative.




SHOP DRAWINGS

Prepare shop drawings showing all information necessary for the fabrication including the main cables, suspender cables, underdeck bracing cables, and connection hardware. The drawings must include the location, type and size of all cables, hangers, fittings, anchorages, and connection hardware accounting for and clearly detailing for tolerances and field adjustments. Shop drawings shall include, as needed:

1. Indicate all materials used, including ASTM standards and technical data sheets for “off-the-shelf” components.

2. Wire diameter and strand construction. 3. Lay and length of lay of wires in each strand. 4. Metallic cross sectional area calculated from supplied wire diameters. 5. Weight per unit length of the manufactured strand and weight of all

attached fittings and hardware. 6. Minimum Breaking Load (MBL) and Modulus of Elasticity of all main

cables and suspenders. 7. Cable marks. 8. Cable cutting procedures. 9. Location and marks of all cable Work Points (WP) referenced to the

specific locations and details shown on the Plans. 10. Show extent of galvanizing of all structural steel connections and fittings. 11. Copies of the Contract Plans will not be considered as meeting these

requirements.

Submit shop drawings signed and sealed by a licensed Illinois Structural Engineer to the Owner’s Representative for review, four weeks prior to requiring comments back, and obtain acceptance prior to start of ordering and fabrication.

ERECTION PROCEDURE

The Contractor’s proposed erection sequence shall be submitted for review and approval by the Owner’s Representative prior to the start of the work. This procedure shall demonstrate that the Contractor understands the behavior of this suspension bridge structure. The Contractor is responsible for the complete erection procedure of the bridge including but not limited to any temporary bracing. The Contractor’s Engineer must submit calculations for the following signed and sealed by an Illinois Licensed Structural Engineer:

1. Methods of transporting the main cable across the ravine. 2. Methods for hoisting the cable onto the tower saddles. 3. Erection procedure identifying stressed structure (tower) geometry and

forces as well as fabrication geometry of main cables and suspender cables at all critical erection stages.

4. Temporary bracing requirements for the towers or floor framing.




5. Anticipated movement of the tower and cable under no load, cable load, and full dead load configurations in order to have plumb towers and the specified cable sag and deck camber after the installation of all dead loads (at 75 degrees F).

6. To obtain plumbness after all dead loads are applied. 7. Anticipated cable elongation. 8. Determination of main cable and suspender cable cut lengths based upon as

measured cable properties (metallic cross sectional areas, actual modulus of elasticity, and load deformation characteristic of each manufactured length of strand), behavior of the main cable (sag) under its own weight and the weight of all dead loads, and the elevations of the helical pile end caps. These lengths shall be coordinated with structural steel connection details. The cable cut lengths must be compatible with the erection procedure utilized by the Contractor.

9. Methods for adjustability and limits (main cable turnbuckles, etc.) 10. Methods/sequence for stressing the underdeck bracing cables.

CERTIFICATION

The cable connection fabricator and/or the cable fitting/component manufacturer must submit certification of the following:

1. Wire mechanical properties in accordance with the referenced standards. 2. Galvanized coating properties in accordance with the referenced standards. 3. Submit copies of certified mill test reports for each heat of steel used for wire

manufacture and for cable connection steel. Mill test reports must include heat and product analysis reports. Mill test reports must be traceable to individual strands.

4. The main cable geometry assume dimensional details which may not be applicable to all strand socket manufacturers. Fabricator shall certify that the as-fabricated main cable and sockets can achieve the minimum cable breaking strength specified herein.

5. The Fabricator shall certify that the suspender cable end connections can achieve the minimum suspender cable breaking strength specified herein.

6. The Fabricator shall certify that the underdeck bracing cable end connections can achieve the minimum underdeck cable breaking strength specified herein.

7. Test results for the cable pre-stretching shall be submitted, including the pre-stretch force and the cable length for the unstretched and pre-stretched conditions.

8. All welds for Cable Saddles are to be magnetic particle tested at critical areas to ASTM E709 with acceptance levels per ASTM E125.




MATERIALS

A. If multiple wire suppliers are used, the same physical characteristics shall be evidenced by all supplied wire through a physical and chemical testing program on actual Project specimens. The testing program shall be submitted for review and acceptance by the Owner’s Representative.

B. Wire ropes for all cables shall be pre-stretched to 50% of their ultimate breaking strength. No splices shall be permitted in the main cables, suspender cables, or bracing cables.

C. After galvanizing, no cold working of wire shall be permitted.

D. All hardware components shall be hot-dipped galvanized in accordance with ASTM A123/A153 and shall be suitable for exterior use.

E. Fittings shall be cast and shall conform to ASTM A148 or approved equal. All cable connections shall be sufficient to develop the minimum breaking strength of the cable.

F. All shackles shall be bolt type with a cotter pin, or other method, to prevent loosening.

MAIN CABLES

A. Main Cables shall consist of wire rope, galvanized, and provided subject to the requirements herein and as described on the Plans. Main cables shall be ASTM A603 with a Class B coating on the outer wires and a Class A coating on the inner wires and have a minimum breaking strength of 68.9 tons.

B. Contractor shall submit details for any open spelter sockets, shackles, turnbuckles, or other components proposed in the connection to the helical pile. The submittal shall include the capacity of each component. The ultimate capacity of each component shall be equal to or greater than the minimum breaking strength of the main cable.

MAIN CABLE SOCKETS

A. Main cables must be attached to sockets using poured zinc conforming to ASTM B6 “High Grade” Zinc Metal (Slab Zinc).

B. The Contractor is responsible for the design and detailing of the main cable sockets. The sockets shall conform to ASTM A148 Grade 90-60, or approved equal. Each socket shall be designed and fabricated to develop the minimum breaking strength of the main cable.

C. Sockets shall be aligned within ±1 percent of the cable centerline.

D. A complete dimensional inspection must be performed on all strand sockets. All machined, forged, or roller components must be subject to a dimensional inspection. All castings are to be magnetic particle tested at critical areas to ASTM E709 with acceptance levels per ASTM E125 as follows:

Linear Discontinuities: Remove by grinding




Shrinkage 2

Inclusions 2

Internal Chills-Chaplets N/A

Porosity 1

D. All casting shall have the following cast on: Pattern number/part number, material grade, heat number, foundry symbol.

E. Unless specified otherwise, discontinuities may be removed by grinding. All repairs shall be in accordance with ASTM A148, supplementary requirements S1 and S2 as specified.

F. All castings shall be heat treated, either by full annealing, normalizing, normalizing, and tempering, or quenching and tempering. The castings may be heat treated by any of these heat treatments at the option of the manufacturer.

G. All strand sockets shall meet or exceed the minimum breaking strength of the strand.

CABLE SADDLES

Cable Saddles shall be prefabricated as shown on the Plans and shall not be field-assembled. Structural Steel for Cable Saddles shall conform to ASTM A709, Grade 50W; pipe for Cable Saddles shall conform to ASTM A53, Grade B. Cable Saddles shall be galvanized after fabrication, in accordance with ASTM A123 or A153. All welding for the cable saddles shall be performed in accordance with American Welding Society (AWS) D1.5 “Bridge Welding Code”.

SUSPENDERS

A. Suspenders shall be wire rope, galvanized, and provided subject to the requirements herein and as described on the Plans. Suspender cables shall be ASTM A603 with a Class B coating on the outer wires and a Class A coating on the inner wires and have a minimum breaking strength of 11.0 tons. Suspender cable components shall include:

• 3-inch by 3/8-inch hanger plate, ASTM A709 Grade 50W (not galvanized)

• Lexco CC-40 Clamps

• Lexco 12HDTHDG Thimble

• Lexco 45050060 Flemish Eyes

• U-bolt with a nut on the top side of the floor beam and double nutted, or other method, on the bottom side to prevent loosening.

B. Suspender Clamps shall be designed to resist sliding without damaging the Main Cable or reducing its capacity.




UNDERDECK BRACING

Underdeck Bracing shall be wire rope, galvanized, and provided subject to the requirements herein and as described on the Plans. Underdeck bracing cables shall be ASTM A603 with a Class B coating on the outer wires and a Class A coating on the inner wires and have a minimum breaking strength of 11.0 tons. All other components of the underdeck bracing cables shall have a minimum capacity of 22 kips, including thimbles, turnbuckles, and shackles, if used.

FABRICATION

A. Main cables, suspender cables, and underdeck bracing cables shall be fabricated in accordance with best current practice and must achieve the minimum breaking strength specified herein. The completed cables must be evenly laid and must be free from injurious imperfection, kinks, loose wires, or other irregularities, and must remain in this condition when unwound from the reel. Proper precautions must be taken and the ends of the cable must be properly secured. All wires must be stranded with uniform tension. Stranding must be sufficiently close to ensure no appreciable reduction in diameter when the cable is subjected to a tension of 10% of the specified MBL.

B. Splicing of finished cable/hanger between end fittings is not permitted.

C. Cable must be fabricated to achieve the minimum value of the modulus of elasticity established in the specification documents. Poured sockets and swaged connections shall only be installed in the cable manufacturer/fabricator’s shop under closely supervised and controlled conditions.




D. Each cable must be pre-stretched prior to final cutting to length to remove constructional stretch and establish uniform elastic load deflection properties. The pre-stretch force shall be 50% of the specified MBL of the strand. The cable must be loaded from the unstressed condition to the maximum pre-stretch force, unloaded to 10% of the specified MBL, and then cycled four (4) times between these two load values (10% to 50%). The load must then be reduced to the cable dead load specified in the Contract Plans. End-to-end length measurements must be made at that load prior to returning the strand to the unstressed condition. If for any reason the cable is distressed after load cycling but before marking to length, then the load cycle process must be repeated and the length measurements made. Cables must be longitudinally striped while under the specified loadings established for length measurement. Cutting of cables must only be done using disc cutters or other approved mechanical devices. Thermal cutting is not permitted. The overall cut lengths including fittings must comply with the following tolerances at the loadings specified in the Contract Plans:

1. Cable lengths less than 30 ft.: ±0.1% of the specified length.

2. Cable lengths exceeding 30 ft.: ±1/2” of the of the specified length.

E. Cable Saddles shall be prefabricated as shown on the Plans and shall not be field-assembled. The pipe for Cable Saddle shall be cut longitudinally and only the lower half used. The bending radius of the pipe section used shall be 25 inches, measured at the inside low point of the pipe for its entire length.

CONSTRUCTION

GENERAL

The minimum bend radius for main cables shall be 25 times nominal cable diameter, or as specified by the cable manufacturer. The minimum bend radius for all other cables shall be in accordance with manufacturer’s specifications.

Suspender Bridge Clamps shall be installed without damaging the Main Cable or reducing its capacity.

DELIVERY, STORAGE, AND HANDLING

All cables, hangers, and connections must be stored in a manner to permit easy access for inspection and identification. Main cables, suspenders, and underdeck bracing cables shall be supported off the ground. Protect cables and packaged materials from corrosion and deterioration. Materials showing evidence of damage will be rejected and must be immediately removed from the site. Strand must be reeled in drums in a manner so that no permanent deformation of individual wires and the strand will occur. Care must be exercised to avoid abrasions and other damage to the galvanized coatings at all times. Cables must not be dragged over any objects that will scrub or abrade the wires. Rotating reels must be used to store and transport the main cables.




TOLERANCES

Unless otherwise specified in AASHTO or AISC, the following tolerances shall be met after the construction of the bridge (dead loads) and at a temperature of 75 degrees F:

1. Tower Plumbness: ±3/8 inch (cable saddle to base plate)

2. Cable Sag at Midspan: ±4 inches

3. Deck Camber: ±2 inches

Note the cable sag and deck camber tolerances above are not additive.

ERECTION

A. Prior to commencing with the erection of main cables and suspenders, inspect the bridge superstructure and cable/hanger anchorage points to verify that the cables/hangers may be erected in accordance with the Plans, Specifications, and the Contractor’s selected erection procedure. In the event of discrepancy, immediately notify the Owner’s Representative in writing. Do not proceed with construction in the region of the discrepancy until all such discrepancies have been resolved.

B. The Contractor shall secure field measurements of cable connection points required for proper and adequate installation of the work covered in this Section and assume responsibility for exact measurements. The Contractor shall notify the Commissioner in writing of variations in the locations of cable connection points with respect to theoretical workpoints indicated in the Plans.

C. Cables must be erected in accordance with the Plans and Specifications and in accordance with the best current practice. Dimensions shown on Plans are based on an assumed design temperature of 75 degrees F. Fabrication and erection procedures must take into account the ambient temperature range at the time of the respective operations. Care must be taken to protect work already installed from damages resulting from cable erection. Cables must be handled with care to prevent denting or nicking of the wires and scratching or scaling to the galvanizing coatings. Dented, kinked, nicked, or otherwise distressed cable and cable connections must be replaced. Cables must not be dragged over any objects that scrub or abrade the wires. When removing strand from a reel, the reel must rotate feely. When lifting a cable into position the attachments should be so connected that no sharp bends are introduced into the cable and the cable is not abraded.

D. Each cable must be positioned such that the relative turns from one end socket to the other end socket (external turns) are a maximum of 10 degrees. This will establish the theoretical position of the longitudinal stripe line as the line from striped end socket to striped end socket.





The work under the main cable and suspender cable item will not be measured separately, it will be paid for as a Lump Sum. Work performed for the underdeck bracing cables will be measured per foot. Work for the cable saddles will be measured as each. These pay items will include all materials, labor, and equipment to design, fabricate, furnish, transport, install, and tension the various cables, components, connections, and saddles used for this structure. It shall also include all labor, equipment, tools, and incidentals to complete the work. Payment for the main cables and suspender cables will be made at the contract unit price per lump sum for FURNISH AND INSTALL MAIN CABLE SYSTEM AND SUSPENDER ASSEMBLIES. Payment for the underdeck bracing cables will be made at the contract unit price per foot for BRACING CABLES. Payment for the cable saddles will be made at the contract unit price per each for CABLE SADDLES.

END OF SECTION



Chase Engineering, LLC Page 37 of 44 Special Provisions: Sealer

PROTECTIVE SEALER

This item shall conform to the requirements of Section 503.19 of the Standard Specifications, except as modified herein:

DESCRIPTION

This Section specifies the requirements to clean and coat concrete surfaces with a silane

sealer on the exposed surfaces of each abutment.

QUALITY ASSURANCE

Pre-Construction Conference: Protective Sealer work is to begin when the Contractor

demonstrates comprehensive understanding of the scope and intent of the Plans relative to

Protective Sealer work. If the Contractor does not demonstrate such knowledge the work

will be halted at the direction of the Owner’s Representative.

MATERIALS

Cleaning Equipment: Sandblasting or waterblasting equipment capable of removing surface contaminants from new and existing concrete surfaces. Compressed air equipment capable of removing dust, dirt, and water from concrete surfaces. Air compressors shall be equipped with suitable separators, traps, or filters which remove water, oil, grease, or other substances from air lines.

Silane Sealer: Clear, monomeric compound containing 100 percent solids. Obtain primary materials from a single manufacturer. Submit written certification from manufacturers that materials comply with environmental regulations applicable at Site.

Use one of following products or approved equal:

1. Sil-Act ATS-100 manufactured by Advanced Chemical Technologies, Inc.

2. Hydrozo 100 manufactured by BASF Construction Chemicals, LLC

3. Protectosil BHN manufactured by Evonik Industries.

Product Data: Submit manufacturer's technical product data, installation instructions, and recommendations. Include data substantiating that material complies with specified requirements.




CONSTRUCTION

DELIVERY, STORAGE, AND HANDLING

Deliver, store, and handle materials according to manufacturer’s recommendations and in such manner as to prevent damage to materials and structure. Deliver materials to Site in original containers and packaging with seals unbroken, labeled with manufacturer’s name, product brand name and type, date of manufacture, lot number, and directions for storing.

Store materials in original, undamaged containers in clean, dry, protected, cool, well-ventilated location on raised platforms with weather-protective coverings, within temperature range required by manufacturer and away from sources of ignition. Protect stored materials from direct sunlight. Manufacturer’s standard packaging and covering is not considered adequate weather protection.

Keep containers tightly sealed when not in use, as atmospheric moisture will react with and alter surface sealer solution. Remove and replace materials that cannot be applied within stated shelf life, or that are damaged or otherwise unsuitable. Conspicuously mark damaged or opened containers or containers with contaminated materials and remove from Site as soon as possible. Dispose of unused or unsuitable materials in accordance with manufacturer’s recommendations and governing environmental regulations. Do not flush debris or surface sealer down existing drains.

CONSTRUCTION REQUIREMENTS

General: Apply surface sealer within range of ambient and substrate temperatures recommended by surface-sealer manufacturer.

Do not apply surface sealer under following conditions, unless otherwise recommended by surface-sealer manufacturer and approved by Owner’s Representative:

1. To substrates that are damp or wet, or that have dew, frost, snow, or ice on them.

2. To substrates below 50 degrees F or less than 5 degrees F above dew point, or above 90 degrees F.

3. When ambient temperature is below 50 degrees F, or is predicted to fall below 50 degrees F within 8 hours after application, or is above 90 degrees F.

4. When rain, snow, fog, or mist is predicted within 24 hours. 5. When wind speeds are at or above 15 miles per hour, or if windy conditions exist

that may cause surface sealer to be blown onto vegetation or surfaces not intended to be treated.

Handle and install materials in strict accordance with safety requirements required by surface sealer manufacturer, Material Safety Data Sheets, and local, state, and federal rules and regulations. Maintain Material Safety Data Sheets with materials in storage area and available for ready reference at Site. Strictly prohibit smoking materials, electrical devices, etc., during delivery, application, and drying phase of combustible liquids. Provide dry-chemical fire extinguishers and clearly post “No Smoking” signs in Work area during surface sealer application and curing.




Surface Preparation: The prepared surfaces are to be clean, dust-free, dry, and are to be approved by the surface sealer manufacturer and the Owner’s Representative. Remove surface contaminants on the concrete to be silane treated by sandblasting. The abrasive grit used for sandblasting shall be contained and properly disposed. Care shall be taken during sandblasting to avoid changing the appearance of the concrete surface. Concrete that becomes contaminated after the initial sandblasting, as determined by the Owner’s Representative, shall be cleaned by sandblasting or another approved means.

Verify that new concrete has cured and aged for the minimum time period recommended by the island manufacturer. The concrete surfaces must be clean and free of dirt, debris, laitance, oils, etc.

Concrete surfaces shall air dry after being wet for at least 3 days before applying sealer. Immediately before applying surface sealer, remove surface contaminants by local light sandblast and clean surface with compressed air blast.

Silane Sealer Application: Apply two (2) coats of the sealer in accordance with the manufacturer’s recommendations. Do not alter or dilute material. Apply sealer only during weather conditions recommended by the manufacturer. If manufacturer's recommendations are incomplete with respect to application rates, an application rate of 125 sq ft/gallon for horizontal surfaces and 175 sq ft/gallon for vertical surfaces is to be used for the silane sealer. Prior to use, thoroughly clean spray equipment, tanks, and hoses, and make free of water, foreign matter, and oily residues. Flush with anhydrous alcohol or small amounts of silane.

Horizontal Surfaces: Apply the water repellent material, utilizing low pressure (15 psi) spray equipment, by ponding it on the surface until the material takes minimum of 5 seconds to be absorbed.

Vertical Surfaces: Using low pressure (15 psi) spray equipment, apply the water repellent materials so it will run down the surface 6 to 8 inches below the spray pattern. Apply from the bottom up.

Protect traffic, personnel, and vegetation from wind-driven overspray. Control silane surface sealer toxic vapors or fumes.

If silane application is not completed at one time, clearly mark location where application is terminated.

Allow silane to dry for at least 12 hours before exposing to construction or pedestrian traffic.





Protective sealer work shall be measured for payment in square feet. The second coat is included in the quantity and will not be paid separately. Payment shall constitute full compensation for properly preparing the concrete surfaces, furnishing the approved material, and for all labor, equipment, tools, and incidentals to complete the work. Payment for the silane sealer application will be made at the contract unit price per square foot for PROTECTIVE SEALER.

END OF SECTION



Chase Engineering, LLC Page 41 of 44 Special Provisions: Handrailing

HANDRAIL

DESCRIPTION

This work shall consist of providing and installing all hardware and fittings, as shown on the Plans. Work shall also include making the pipe attachment to the suspender plates and cable attachment through the suspender plates, including providing all necessary hardware for this work. This item also includes the provision and installation of “aircraft” cables in the handrail. Work shall also include providing and installing railing endposts.

GENERAL


Contractor shall submit all proposed components for the handrail for review and approval by the Owner’s Representative prior to ordering and fabrication.

Fabricate end posts and handrail pipes in a manner that will not collect water. Provide a weep hole at the base of each post, and as needed in the handrail pipe, to allow condensation to drain.

Assemble railings in the shop to the greatest extent possible to minimize field splicing and assembly. Use connections that maintain structural value of the joined pieces. Splices in the handrail pipe shall be submitted for review, including the splice detail and the locations. Splices that are welded in the field shall have the galvanizing repaired in the vicinity of the splice using a method that is acceptable to the Owner’s Representative.

MATERIALS

HANDRAILING CABLES

Handrailing Cables shall be “aircraft” cable, stainless steel or bright galvanized, and provided subject to the requirements herein and as described on the Plans meeting the requirements of ASTM A492. The minimum breaking strength of the cable and all attachments shall be 3.5 kips.

HANDRAIL PIPES

Handrailing pipe shall be composed of extra-strong structural steel pipe meeting the requirements of ASTM specification A53, Grade B, and provided subject to the requirements herein and as described on the Plans. The pipe shall be hot-dipped galvanized in accordance with ASTM A123. Installed pipes shall be free of imperfections and all burrs shall be removed. Plates to connect the pipe rail to the suspender plates and handrail end posts shall be ASTM A709 Grade 50W.



Chase Engineering, LLC Page 42 of 44 Special Provisions: Handrailing

HANDRAIL ENDPOSTS

Handrailing Endposts shall be composed of structural steel tubes, composed of weathering steel and meeting the requirements of ASTM specification A847, and provided subject to the requirements herein and as described on the Plans.

ANCHOR BOLTS

Anchor bolts for the end posts, as shown on the Plans, shall be ASTM F1554, Grade 55 and hot-dipped galvanized. Anchor bolts shall be cast into the concrete abutments, and not post-installed. Heavy hex nuts shall be per ASTM A563 and washers per ASTM F436. Hardware shall be galvanized per ASTM A153. Provide two nuts per anchor bolt to prevent loosening.

FITTINGS

Fittings shall conform to sub-Section 1006.28 of the Standard Specifications and shall be hot-dipped galvanized or stainless steel to match the cable.

CONSTRUCTION

All welding of brackets and connections, as shown on the Plans, shall be done in accordance with AWS D1.5. Weld procedures shall be submitted for review and approval by the Owner’s Representative prior to fabrication.


Measurement shall be taken between ends of end caps at each handrail end post and shall include all pipes, cables, fittings, handrail end posts, and anchor bolts, as accepted by the Owner’s Representative, along the length of the bridge, for a total of two handrail lengths (one per side of the bridge). Payment shall constitute full compensation for fabricating, furnishing, and installing all handrail components, and for all labor, equipment, tools, and incidentals to complete the work. Payment for the handrail will be made at the contract unit price per foot for HANDRAIL.

END OF SECTION



Chase Engineering, LLC Page 43 of 44 Special Provisions: Gates

END GATES

DESCRIPTION

This work shall consist of installing two gates in conformance with the Plans. Gates shall be erected between end posts of the railing system.

GENERAL

Work not specified herein shall conform to Section 664 of the Standard Specifications. Work shall conform to Plans.

Gate may be made from a pre-fabricated panel or fabricated from pieces to fit the dimensions shown on the drawings.

Contractor shall submit shop drawing for review and approval by the Owner’s Representative, which shall include the gate layout, dimensions, components, weld designations, hinge and connection details, lock specifications. Manufacturer data sheets shall be included for all “off-the-shelf” components.

MATERIALS

Gates shall be composed of uncoated structural weathering steel, ASTM A709 Grade 50W or ASTM A847, galvanized chain-link fence, and/or other material as approved by the Owner's Representative.

CONSTRUCTION

Gates shall be equipped with a lock and corresponding hasp at the handrail end post on the corresponding end. A mechanism shall be installed allowing for the gate to be held in the open position. Each gate shall be supported on a minimum of three heavy-duty hinges attached to the handrail end post.


Payment shall include framing members, chain-link fencing, hinges, locking mechanisms, and warning signs, as accepted by the Owner’s Representative, at each end of the bridge. Payment shall constitute full compensation for fabricating, furnishing, installing, the end gates, and for all labor, equipment, tools, and incidentals to complete the work. Payment for the gates will be made at the contract unit price per each for END GATES.

END OF SECTION



Chase Engineering, LLC Page 44 of 44 Special Provisions: Appendix 1

APPENDIX 1 – GEOTECHNICAL REPORT AND SOIL BORING LOGS

Subsurface Exploration and Geotechnical Engineering Report

Pedestrian Suspension Bridge in McCormick Ravine Lake Forest, Illinois

Submitted to:

Ms. Cathy Czerniak City of Lake Forest

800 Field Drive

Lake Forest, IL 60045

Lake Forest Open Lands/Lake Forest Land Foundation

350 North Waukegan Road


Submitted by:

GEI Consultants, Inc. 120 W. Madison Street, Suite 1305 Chicago, IL 60602

January 29, 2019

Project 1804995

Matthew E. Ribordy, P.E.

Senior Professional

Consulting

Engineers and

Scientists

GEI Consultants, Inc.

400 N. Lakeview Parkway, Suite 140, Vernon Hills, IL 60061

847.984.3401 fax: 847.984.3532

www.geiconsultants.com

January 29, 2019

Project No. 1804995

VIA EMAIL: [email protected]

Ms. Cathy Czerniak

City of Lake Forest

800 Field Drive


Lake Forest Open Lands/ Lake Forest Land Foundation

350 North Waukegan Road


Re: Subsurface Exploration and Geotechnical Engineering Report for Pedestrian

Suspension Bridge in McCormick Ravine in Lake Forest, IL

Dear Ms. Czerniak:

GEI Consultants, Inc. (GEI) has completed our subsurface exploration and geotechnical

engineering recommendations for the Pedestrian Bridge planned at McCormick Ravine in

Lake Forest, IL.

Based on the information obtained from our subsurface exploration, it is our opinion that

shallow foundations are suitable to support the bridge at this site. An allowable bearing

pressure of 4,000 pounds per square foot is recommended.

We appreciate the opportunity to provide our services for this project. Please do not hesitate

to call with any questions with regard to our report.

Sincerely,

GEI CONSULTANTS, INC.

Ati Fathi, P.E. Matthew E. Ribordy, P.E.

Senior Professional Senior Professional

Consulting

Engineers and

Scientists

mailto:[email protected]

Subsurface Exploration and Geotechnical Engineering Report Pedestrian Suspension Bridge in McCormick Ravine – Lake Forest, IL January 29, 2019

GEI Consultants, Inc. i

Table of Contents

1. Site and Project Description 1

1.1 Introduction 1

2. Exploration Procedures 2

2.1 Subsurface Exploration 2

2.2 Laboratory Procedures 2

3. Subsurface Conditions 3

3.1 Soil Conditions 3

3.2 Groundwater Conditions 3

4. Foundation Recommendations 4

4.1 Spread Footing Foundations 4

4.2 Sliding Resistance 4

4.3 Uplift Loads 5

4.4 Spread Footing Construction Considerations 5

4.5 Seismic Considerations 6

5. Limitations 7

6. Appendix C 10

Appendices

A. Bridge Location Diagram

B. Boring Location Diagram

C. Soil Boring Logs

D. General Notes


1


1. Site and Project Description

1.1 Introduction

GEI Consultants, Inc. (GEI) has prepared this report for The City of Lake Forest and

Lake Forest Open Lands/Lake Forest Land Foundation in accordance with our proposal

dated December 7, 2018. The purposes of this report are to consolidate the field and

laboratory test data, and to provide recommendations regarding the design and

construction of foundations for the project.

We understand that a new pedestrian suspension bridge of primarily steel construction is

planned at the McCormick Ravine. The bridge consists of 18-foot twin steel towers with

an approximate 100-foot span. Dead load is about 70 pounds per foot per side (140

pounds per lineal foot of the deck). The mainline axial force in tension is about 31 kips

and the compression vertical force in the tower is about 23.25 kips.


2


2. Exploration Procedures

2.1 Subsurface Exploration

A total of four (4) soil borings were completed as part of the field geotechnical exploration

program. The soil boring locations are shown on the Soil Boring Location Diagram in

Appendix B.

The soil borings were performed with an ATV-mounted drill rig using various cutting bits to

advance the boreholes. Representative soil samples were obtained by means of split barrel

sampling procedures in conformance with ASTM Standards D-1586. The soil sampling

interval ranged from 2.5-foot intervals to 5-foot depth intervals. Samples obtained in the field

were logged, labeled, sealed and brought to our Vernon Hills, Illinois laboratory for further

observation and testing. The boring logs are included in Appendix B.

During the field operations, the drilling crew maintained a written log of the subsurface

conditions including changes in the stratigraphy and observed groundwater level. The drilling

crew also made water level observations in the boreholes both during and upon completion of

the drilling and sampling operations. Upon completion of the drilling operations, the

boreholes were backfilled soil cuttings and bentonite chips.

2.2 Laboratory Procedures

Representative portions of the recovered soil samples were visually examined by a

geotechnical engineer to estimate the distribution of grain sizes, plasticity, organic content,

moisture condition, color, presence of lenses and seams, and apparent geological origin. A

calibrated hand penetrometer was used to estimate the approximate unconfined compressive

strength of the cohesive soil samples. The soils were classified in accordance with our

standard practice and assigned group symbols consistent with those recommended by the

Unified Soil Classification System. A chart describing the classification system is included

in Appendix C attachments.

Results of the field and laboratory tests were plotted on the boring logs which are included in

the attachments. Similar soils were grouped into strata on the logs. Please note that the

strata contact lines represent approximate boundaries between soil types. The actual

transition between soil types in the field may be gradual in both the horizontal and vertical

directions.

All samples recovered from the borings will be retained for a minimum period of 60 days,

after which time they may be discarded unless other specific instructions as to their

disposition are received


3


3. Subsurface Conditions

3.1 Soil Conditions

The subsurface profile consisted of mostly very stiff to hard silty clay extending 19 to 23 feet

below the existing grades, underlain by a layer of sand and silty sand.

3.2 Groundwater Conditions

Groundwater was not encountered in the borings at the time of drilling and before the borings

were backfilled. Based on the change in color from brown to gray in samples, we

recommend the design groundwater be assumed at about 13 feet below the surface, for

design purposes. Groundwater levels may change during the course of years, and seasonal

fluctuations in groundwater levels should be expected depending upon variations in

precipitation, evaporation, and surface runoff.


4


4. Foundation Recommendations

4.1 Spread Footing Foundations

The results of this exploration indicate that the subsurface conditions at the site are generally

suitable for the use of spread footings for support of the proposed bridge.

Footings founded on the very stiff to hard native clay soils or new fill may be designed using

a net allowable soil bearing pressure of 4,000 psf. The net allowable bearing pressure is the

maximum pressure that should be transmitted to the bearing soils in excess of the minimum

surrounding overburden pressure.

At the maximum bearing pressures, the total settlement of footing foundations designed as

recommended above are estimated to be between 0.5 and 1 inch. Differential settlements are

possible due to varying foundation loads and support conditions but are estimated to be less

than about ½ inch.

4.2 Sliding Resistance

The resistance to sliding of footings can be evaluated using the earth pressure coefficients

and interface friction value tabulated below.

Table 1: Earth pressure coefficients and interface friction values

Interface Friction

Factor, tan

Earth Pressure Coefficients

Active, Ka Passive, Kp At-Rest, K0

Granular Backfill

(Sides of foundation) 0.45 0.25 3.85 0.40

Footings

(Mass Concrete on New Fill) 0.55 - - -

(Precast Concrete Against New Fill) 0.45 - - -

In the equation below, a reduction factor of 2 is applied to passive pressure against the

foundations to account for reduced mobilization at small deflections. To fully develop

passive resistance would require deflections on the order of 2.5 to 4 inches. A unit weight of

125 pcf can be assumed for the granular backfill.

Passive Resistance: 𝑃𝑝 = [1

2(𝑘𝑝

2− 𝑘𝑎)𝛾𝐻

2 ] (per unit width in direction of loading)

Sliding resistance on the sides of the foundations should be calculated as the resultant

confining (normal) stress over the height of the element times the interface friction angle,

times the length of the element in the direction of loading, or


5


Side Resistance on Mat: 𝑃𝑠 =[1

2𝑘𝑎𝛾𝐻𝑚𝑎𝑡

2 tan𝛿𝐿𝑚𝑎𝑡]

1.5(per element parallel to loading)

The equation above includes a reduction factor of 1.5 to account for strain compatibility.

The resistance to sliding of footing foundations is determined as the vertical normal stress

times the area of contact, times the interface friction factor. In the values tabulated above, it

is assumed that footing foundations are constructed on tested and approved backfill. A

minimum factor of safety of 1.5 should be provided against sliding.

4.3 Uplift Loads

Footing foundations that will be subjected to uplift and lateral loads should be embedded

sufficiently to resist these loads. Uplift loads on footings may be resisted by the weight of

the footing in addition to the weight of the soil directly above the footing. A total unit weight

of 110 pounds per cubic foot (pcf) may be assumed for compacted soil above the foundation.

Horizontal loads acting on foundations backfilled with engineered fill may be resisted by a

combination of passive pressure on the sides of the footing and sliding friction at the base of

the footing. If net uplift loads will accompany horizontal loads, the contribution of sliding

friction to the horizontal load capacity should be neglected. Passive resistance for

foundations backfilled with granular engineered fill may be calculated using an equivalent

fluid unit weight of 360 pounds per cubic foot (pcf). Passive pressure should be ignored

within 3 feet of the ground surface due to potential frost disturbance. Appropriate safety

factors should be applied to the ultimate friction and equivalent fluid unit weight values

provided.

4.4 Spread Footing Construction Considerations

Foundation excavations and excavations that are to receive compacted fill should be kept free

of standing water. In addition, all soils which become softened or loosened at the base of

foundation excavation areas or subgrade areas should be carefully re-compacted or removed

prior to placement of foundation concrete or fill material. No foundation concrete or

structural fill should be placed in areas of ponded water or frozen soil. All excavations

should be constructed in the dry such that they provide a safe and stable excavation at slopes

no steeper than 1.5H:1V, unless excavations are less than 4 feet deep. OSHA regulations

regarding excavation side slopes in dry and wet soil conditions should be followed.

All foundation and subgrade soils should be observed by a representative of GEI prior to

placement of concrete or fill to confirm that the subgrade conditions are consistent with the

design assumptions and recommendations contained in this report. Periodic density testing

should be performed on any fill to document that density requirements have been met.


6


Wherever soft, loose or otherwise unsuitable material is present at the bearing elevation, the

material should be removed and replaced with engineered fill.

The overexcavation should extend in all directions at least 8 inches beyond the edges of the

footings for each 12 inches of overexcavated depth below the footing level. The backfill

should consist of a well-graded granular material, containing less than 12% by weight

passing the No. 200 (0.075 mm) sieve (preferably IDOT grade CA-6). This material should

be placed in thin lifts not exceeding 9 inches in loose thickness, and it should be compacted

to a minimum of 95% of its maximum dry density as determined by the modified Proctor test

(ASTM D 1557). Thinner lifts should be used where material is compacted with light or

walk-behind equipment.

Footings placed in unheated areas should be embedded a minimum of 4 feet below finished

grade to provide for adequate frost protection. Individual column footings should have a

minimum width of 30 inches to prevent disproportionately small footing sizes.

4.5 Seismic Considerations

In accordance with Standard 9 of ASCE 7: Minimum Design Loads for Buildings and Other

Structures, we recommend that Site Classification D be used for seismic design based on site

specific SPT tests, vane shear tests, and the laboratory shear strength measurements of

recovered soil samples.


7


5. Limitations

This report was prepared for the exclusive use of City of Lake Forest and Lake Forest Open

Lands/Lake Forest Land Foundation for foundation design and recommendations of the

proposed pedestrian bridge. This report has been prepared based on the geotechnical

investigation data and structural layout information provided to us. This report may require

modification if there are any changes in the nature, design, or location of the proposed

structures. We cannot accept responsibility for designs based on our recommendations

unless we are engaged to review the final plans and specifications to evaluate whether any

changes in the project affect the validity of our recommendations and whether our

recommendations have been properly implemented in the design.

Variations in soil conditions exist on most sites between boring locations, and seasonal and

annual fluctuations in groundwater levels will likely occur. The nature and extent of

variations between explorations may not become evident until construction. If variations

from the anticipated conditions are encountered, it may be necessary to revise the

recommendations in this report. Therefore, we recommend that GEI be engaged to make site

visits during construction to: a) check that the subsurface conditions exposed during

construction are in general conformance with our design assumptions and b) ascertain that, in

general, the geotechnical aspects of the work are being performed in compliance with the

contract documents.

The Geotechnical Engineer of Record is the professional engineer who authored this

geotechnical report. It is recommended that all construction operations dealing with

earthwork and foundations be observed by the Geotechnical Engineer of Record, or the

Geotechnical Engineer’s appointed representative, to confirm that design requirements are

fulfilled in the actual construction. For some projects, this may be required by the governing

construction regulator.

It was not part of our scope to explore for, or research the locations of, buried utilities or

other buried structures at the site. Before construction of foundations for the proposed

structure, a diligent effort should be made to determine the presence and location of any

buried structures, including utilities. This effort should include a thorough review of

available drawings and other records of the site use and facilities. If the presence of such

structures is determined to be likely, GEI should be notified so that we may review and

revise our recommendations, if appropriate.

Our professional services for this project have been performed in accordance with generally

accepted engineering practices; no warranty, expressed or implied, is made.


8


Appendix A

Bridge Location Diagram

McCormick Ravine

Janes R

avine

No-Name

Ravine

Swinging Bridge Location

0 1,000 2,000500 Feet

ÜMcCormick_Property_LineExisting McCormick TrailContour Lines 1' Interval

This map application was prepared with geographic information system (GIS) data created by Lake Forest Open Lands Association and Lake County Mapping/GIS Division. These entities do not warrant or guarantee the accuracy or suitability of GIS data for any purpose.

The GIS data within this map is intended to be used as a general index to spatial information and not intended for detailed, site-specific analysis or resolution of legal matters.

RyanL

Oval

RyanL

Callout

Bridge Location


9


Appendix B

Soil Boring Location Diagram

Janes R

avine

No-Name Ravin

e

McCormick Ravine

0 1,000 2,000500 Feet

ÜThis map application was prepared with geographic information system (GIS) data created by Lake Forest Open Lands Association and Lake County Mapping/GIS Division.

These entities do not warrant or guarantee the accuracy or suitability of GIS data for any purpose. The GIS data within this map is intended to be used as a general index to spatial information and not intended for detailed, site-specific analysis or resolution of legal matters.

12

3

4

RyanL

Oval

RyanL

Oval

RyanL

Oval

RyanL

Oval

RyanL

Line

RyanL

Line

RyanL

Line

RyanL

Line


10


6. Appendix C

Soil Boring Logs

SS

SS

SS

SS

SS

SS

SS

1

2

3

4

5

6

7

(0.0)Silty Clay, trace sand and gravel, very stiff to hard,brown/gray to gray (CL)

large gravel noted

with gravel at about 18 feet

(23.5)Silty Sand, brown, medium dense, dry (SM)

End of Boring

Boring advanced with a hollow stem auger.3.25 inch casing was installed.Standard Penetration Tests performed with an automatichammer.Boring backfilled upon completion.

SA

MP

LE D

IST

AN

CE

RE

CO

VE

RY

SA

MP

LE T

YP

E

SA

MP

LE N

O.

LIQUIDLIMIT (%)

WATERCONTENT (%)

PLASTICLIMIT (%)

STANDARD PENETRATION BLOWS/FT10 20 30 40 50 60

LOCATION: Lake Forest, IL

UN

IT D

RY

WT

.LB

S/F

T3

DE

PT

H (

FT

)

5

10

15

20

25

30

10 20 30 40 50

UNCONFINED COMPRESSIVE STRENGTHTONS/FT2

1 2 3 4 5

DESCRIPTION OF MATERIAL

SURFACE ELEVATION (ft)

ELE

VA

TIO

N (

ft)

BORING STARTED1/18/2019

PAGE NO. 1 OF 1

BORING COMPLETED1/18/2019

The stratification lines represent the approximate boundary lines between soil types: in situ, the transition may be gradual.

APPROVED BYMER

RIG/FOREMAND-50 (Geocon) / N. Jones

GEI OFFICEChicago Area

GEI PROJECT NO.1804995

ENTERED BYAF

WATER LEVEL: Not Encountered

D R A F T

STATION OFFSET ft R

MID

WE

ST

BO

RIN

G L

OG

- O

FF

ICIA

L M

CC

OR

MIC

K R

AV

INE

PE

DE

ST

RIA

N S

US

PE

NS

ION

BR

IDG

E.G

PJ

TP

L_G

EI_

MID

WE

ST

_BE

TA

.GD

T 1

/29/

19

CLIENT:City of Lake Forest/Lake Forest Open Lands/Lake Forest Land Foundation

PROJECT NAME:McCormick Ravine Pedestrian Suspension Bridge

LOG OF BORING NUMBER B-1

10

20

21

25

20

17

25

2.5

4.5+

4.5+

4.5+

4.25

2.25

SS

SS

SS

SS

SS

SS

SS

1

2

3

4

5

6

7


End of Boring


SA

MP

LE D

IST

AN

CE

RE

CO

VE

RY

SA

MP

LE T

YP

E

SA

MP

LE N

O.

LIQUIDLIMIT (%)

WATERCONTENT (%)

PLASTICLIMIT (%)



UN

IT D

RY

WT

.LB

S/F

T3

DE

PT

H (

FT

)

5

10

15

20

25

30

10 20 30 40 50


1 2 3 4 5



ELE

VA

TIO

N (

ft)


PAGE NO. 1 OF 1



APPROVED BYMER




ENTERED BYAF


D R A F T

STATION OFFSET ft R

MID

WE

ST

BO

RIN

G L

OG

- O

FF

ICIA

L M

CC

OR

MIC

K R

AV

INE

PE

DE

ST

RIA

N S

US

PE

NS

ION

BR

IDG

E.G

PJ

TP

L_G

EI_

MID

WE

ST

_BE

TA

.GD

T 1

/29/

19

CLIENT:City of Lake Forest/Lake Forest Open Lands/Lake Forest Land FoundationPROJECT NAME:McCormick Ravine Pedestrian Suspension Bridge


15

18

22

21

22

20

18

2.5

4.5+

4.5+

4.5+

4.5+

4.5+

2.5

SS

SS

SS

SS

SS

SS

SS

1

2

3

4

5

6

7


(19.0)Fine Sand, brown, medium dense, dry (SP)

End of Boring


SA

MP

LE D

IST

AN

CE

RE

CO

VE

RY

SA

MP

LE T

YP

E

SA

MP

LE N

O.

LIQUIDLIMIT (%)

WATERCONTENT (%)

PLASTICLIMIT (%)



UN

IT D

RY

WT

.LB

S/F

T3

DE

PT

H (

FT

)

5

10

15

20

25

30

10 20 30 40 50


1 2 3 4 5



ELE

VA

TIO

N (

ft)


PAGE NO. 1 OF 1



APPROVED BYMER




ENTERED BYAF


D R A F T

STATION OFFSET ft R

MID

WE

ST

BO

RIN

G L

OG

- O

FF

ICIA

L M

CC

OR

MIC

K R

AV

INE

PE

DE

ST

RIA

N S

US

PE

NS

ION

BR

IDG

E.G

PJ

TP

L_G

EI_

MID

WE

ST

_BE

TA

.GD

T 1

/29/

19

CLIENT:

City of Lake Forest/Lake Forest Open Lands/Lake Forest Land FoundationPROJECT NAME:McCormick Ravine Pedestrian Suspension Bridge


11

13

21

22

12

25

20

4

4.25

4.5+

2.5

2.5

SS

SS

SS

SS

SS

SS

SS

1

2

3

4

5

6

7

(0.0)Silty Clay, trace sand and gravel, very stiff to hard,brown/gray (CL)

turning gray

(23.5)Fine Sand, brown, dense, dry (SP)

End of Boring


SA

MP

LE D

IST

AN

CE

RE

CO

VE

RY

SA

MP

LE T

YP

E

SA

MP

LE N

O.

LIQUIDLIMIT (%)

WATERCONTENT (%)

PLASTICLIMIT (%)



UN

IT D

RY

WT

.LB

S/F

T3

DE

PT

H (

FT

)

5

10

15

20

25

30

10 20 30 40 50


1 2 3 4 5



ELE

VA

TIO

N (

ft)


PAGE NO. 1 OF 1



APPROVED BYMER




ENTERED BYAF


D R A F T

STATION OFFSET ft R

MID

WE

ST

BO

RIN

G L

OG

- O

FF

ICIA

L M

CC

OR

MIC

K R

AV

INE

PE

DE

ST

RIA

N S

US

PE

NS

ION

BR

IDG

E.G

PJ

TP

L_G

EI_

MID

WE

ST

_BE

TA

.GD

T 1

/29/

19

CLIENT:City of Lake Forest/Lake Forest Open Lands/Lake Forest Land Foundation

PROJECT NAME:McCormick Ravine Pedestrian Suspension Bridge


11

17

20

18

12

14

37

4.5+

4.5+

4.5+

4.5+

3

3


11


Appendix A

General Notes

LETTERGRAPH

SYMBOLSMAJOR DIVISIONS

SOIL CLASSIFICATION CHART

PT

OH

CH

MH

OL

CL

ML

SC

SM

SP

COARSEGRAINED

SOILS

SW

TYPICALDESCRIPTIONS

WELL-GRADED GRAVELS, GRAVEL -SAND MIXTURES, LITTLE OR NOFINES

POORLY-GRADED GRAVELS,GRAVEL - SAND MIXTURES, LITTLEOR NO FINES

SILTY GRAVELS, GRAVEL - SAND -SILT MIXTURES

GC

GM

GP

GW

CLAYEY GRAVELS, GRAVEL - SAND -CLAY MIXTURES

WELL-GRADED SANDS, GRAVELLYSANDS, LITTLE OR NO FINES

POORLY-GRADED SANDS,GRAVELLY SAND, LITTLE OR NOFINES

SILTY SANDS, SAND - SILTMIXTURES

CLAYEY SANDS, SAND - CLAYMIXTURES

INORGANIC SILTS AND VERY FINESANDS, ROCK FLOUR, SILTY ORCLAYEY FINE SANDS OR CLAYEYSILTS WITH SLIGHT PLASTICITY

INORGANIC CLAYS OF LOW TOMEDIUM PLASTICITY, GRAVELLYCLAYS, SANDY CLAYS, SILTY CLAYS,LEAN CLAYS

ORGANIC SILTS AND ORGANICSILTY CLAYS OF LOW PLASTICITY

INORGANIC SILTS, MICACEOUS ORDIATOMACEOUS FINE SAND ORSILTY SOILS

INORGANIC CLAYS OF HIGHPLASTICITY

ORGANIC CLAYS OF MEDIUM TOHIGH PLASTICITY, ORGANIC SILTS

PEAT, HUMUS, SWAMP SOILS WITHHIGH ORGANIC CONTENTS

CLEANGRAVELS

GRAVELS WITHFINES

CLEAN SANDS

(LITTLE OR NO FINES)

SANDS WITHFINES

LIQUID LIMITLESS THAN 50

LIQUID LIMITGREATER THAN 50

HIGHLY ORGANIC SOILS

NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS

GRAVELAND

GRAVELLYSOILS

(APPRECIABLEAMOUNT OF FINES)

(APPRECIABLEAMOUNT OF FINES)

(LITTLE OR NO FINES)

FINEGRAINED

SOILS

SANDAND

SANDYSOILS

SILTSAND

CLAYS

SILTSAND

CLAYS

MORE THAN 50%OF MATERIAL ISLARGER THANNO. 200 SIEVE

SIZE

MORE THAN 50%OF MATERIAL ISSMALLER THANNO. 200 SIEVE

SIZE

MORE THAN 50%OF COARSEFRACTION

PASSING ON NO.4 SIEVE

MORE THAN 50%OF COARSEFRACTION

RETAINED ON NO.4 SIEVE