IVheber-ut.granicus.com/DocumentViewer.php?file=heber-ut_5...Millstream Properties Job No. 1614-001-14 Geotechnical Study May 6, 2014 3. 3.2 Moisture Content and Dry Density Tests

GSH

REPORT

GEOTECHNICAL STUDY

VALLEY HILLS DEVELOPMENT

NORTH & WEST OF 1050 NORTH MILL ROAD

HEBER CITY, UTAH

Submitted To:

Millstream Properties380 East Main Street, Building B

Heber City, Utah 84049

Submitted By:

GSH Geotechnicai, Inc.473 West 4800 South

Salt Lake City, Utah 84123

May 6, 2014

Job No. 1614-001-14

IV

May 6, 2014Job No. 1614-001-14

Mr. Brad LyleMillstream Properties380 East Main Street, Building BHeber City, Utah 84049

Mr. Lyle:

Re: ReportGeotechnical StudyValley Hills DevelopmentNorth and West of 1050 North Mill Road

Heber City, Utah(40.5211 N;-111.3966 W)

1. INTRODUCTION

1.1 GENERAL

This report presents the results of our geotechnical study performed for the proposed Valley HillsDevelopment to be located north and west of 1050 North Mill Road in Heber City, Utah. Thegeneral location of the site with respect to major topographic features and existing facilities, as of1997, 1998, and 1999, is presented on Figure 1, Vicinity Map. A more detailed layout of the siteshowing the proposed locations of the site and the surrounding area and streets is presented onFigure 2, Site Plan. The locations of the test pits excavated in conjunction with this study arealso presented on Figure 2.

1.2 OBJECTIVES AND SCOPE

The objectives and scope of our study were planned in discussions between Mr. Paul Berg ofBerg Engineering and Mr. Bill Turner of GSH Geotechnical, Inc. (GSH).

In general, the objectives of this study were to:

1. Define and evaluate the subsurface soil and groundwater (if encountered)

conditions at the site.

GSH Geotechnical, Inc.473 West 4800 South

Salt Lake City, Utah 84123Tel: (801) 685-9190www.gshgeo.com

GSH Geotechnical, Inc.1596 West 2650 South, Suite 107Ogden, Utah 84401Tel: (801) 393-2012www.gshgeo.com

Millstream PropertiesJob No. 1614-001-14

Geotechnical StudyMay 6, 2014

Mr

2. Provide appropriate foundation, earthwork, pavement and geoseismic

recommendations to be utilized in the design and construction of the proposeddevelopment.

In accomplishing these objectives, our scope has included the following:

1. A field program consisting of the excavation, logging, and sampling of 8 test pits.

2. A laboratory testing program.

3. An office program consisting of the correlation of available data, engineering

analyses, and the preparation of this summary report.

1.3 AUTHORIZATION

Authorization was provided by returning a signed copy of our Professional Services AgreementNo. 14-0410 dated April 4, 2014.

1.4 PROFESSIONAL STATEMENTS

Supporting data upon which our recommendations are based are presented in subsequent sectionsof this report. Recommendations presented herein are governed by the physical properties of thesoils encountered in the exploration test pits, projected groundwater conditions, and the layoutand design data discussed in Section 2, Proposed Construction, of this report. If subsurfaceconditions other than those described in this report are encountered and/or if design and layoutchanges are implemented, GSH must be informed so that our recommendations can be reviewedand amended, if necessary.

Our professional services have been performed, our findings developed, and ourrecommendations prepared in accordance with generally accepted engineering principles andpractices in this area at this time.

2. PROPOSED CONSTRUCTION

It is our understanding that the proposed construction consists of developing the 21.5-acre sitefor constructing single-family residences. The residences will be supported on conventionalspread and strip footings, with basement levels. Associated streets and utilities will also beconstructed to provide access and services to the residences. Projected traffic consists of a lightto moderate volume of vehicles consisting mostly of autos and pickup trucks, with a dailydelivery (medium) truck and weekly to occasional heavy trucks. It is anticipated that sitegrading will consist of up to 8 feet of cut and/or fill throughout the site.

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3. INVESTIGATIONS

3.1 FIELD PROGRAM

In order to define and evaluate the subsurface soil and groundwater conditions at the site, 8 testpits were excavated on April 18, 2014 to depths of about 0.5 to 12.0 feet below existing grade.The test pits were excavated using a track-mounted 325C Cat backhoe. Locations of the test pitsare presented on Figure 2.

The field portion of our study was under the direct control and continual supervision of anexperienced member of our geotechnical staff. During the course of the excavation operations, acontinuous log of the subsurface conditions encountered was maintained. In addition, smalldisturbed samples of the typical soils encountered were obtained for subsequent laboratorytesting and examination. The soils were classified in the field based upon visual and texturalexamination. These classifications have been supplemented by subsequent inspection and testingin our laboratory. Detailed graphical representation of the subsurface conditions encountered ispresented on Figures 3A through 3H, Test Pit Logs. Soils were classified in accordance with thenomenclature described on Figure 4, Key to Test Pit Log (USCS).

Samples representative of the soil layers encountered were obtained and placed in sealable bags.Although an effort was made to compact the backfill with the backhoe within each test pit,backfill was not placed in uniform lifts and compacted to a specific density. Consequently,settlement of the test pit backfill material with time is likely to occur.

3.2 PERCOLATION TESTING

Percolation testing was performed in Test Pit TP-1 at a depth of about 5 feet below the existingground surface. The soils encountered at this depth consisted of clayey fine to medium sandwith some silt. A small hole about 12 inches deep and 12 inches in diameter was excavated intothe ground, filled with water, and allowed to completely soak into the ground. The hole wasagain filled with water and the depth of water drop with time was measured. The finalmeasurement indicated the percolation rate was 19.2 minutes per inch. For design, werecommend using a percolation rate of 20 minutes per inch.

3.3 LABORATORY TESTING

3.3.1 General

In order to provide data necessary for our engineering analyses, a laboratory testing program wasperformed. The program included moisture content, dry density, Atterberg Limits, and partialgradation tests. The following paragraphs describe the tests and summarize the test data.

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3.3

.2 Moisture Content and Dry Density Tests

To aid in classifying the soils and to help correlate other test data, moisture content and drydensity tests were performed on selected undisturbed samples and moisture content tests wereperformed on other disturbed samples. The results of these tests are presented on the test pitlogs, Figures 3A through 3H.

3.3

.3 Atterberg Limits

To aid in classifying the soils and to provide general index parameters, liquid limit and plasticlimit tests (Atterberg Limits) were performed upon representative samples of the soilsencountered in the exploration test pits. The results of the tests are tabulated below:

Sieve Size TP-1 @ 2 ft TP-7 (a) 1 ft TP-7 (a), 2 ft

Liquid Limit 28 64 47

Plastic Limit 15 20 22

Plasticity Index 13 44 25

Soils Classification CL CH CL

3.3

.4 Partial Gradation Tests

To aid in classifying the soils and to provide general index parameters, partial gradation testswere performed upon representative samples of the soils encountered in the exploration test pits.The results of the tests are tabulated below:

Sieve Size

Percent Passing

TP-1

(a] 3 ft

TP-1

@ 6 ft

TP-1

@ 8 ft

TP-2

@ 6 ft

TP-2

@ 8 ft

TP-4

@9 ft

TP-7

@4 ft

No. 200 25 36 20 11 4 16 8

Soils

ClassificationSM SC SM SP-SM GP SM SP-SM

4. SITE CONDITIONS

4.1 SURFACE

The site is located on undeveloped land. Vegetation consisted of grass/weeds, sage brush, and anoccasional tree. The topography of the site essentially comprises a north-to-south ridge that

LI

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Geotechnical StudyMay 6,2014

generally slopes downward toward the south/southwest with nearly 100 feet of elevationdifference from north to south. The site is bordered on the northwest by existing residences, onthe north by a canal, on the east by a dirt road and similar undeveloped land and a single-familyresidence, on the south by 1050 North Street and residences, and on the west by Valley HillsBoulevard.

4.2 SUBSURFACE SOIL AND GROUNDWATER

The soil conditions encountered in the test pits varied, depending on the depth and hardness ofbedrock that was or was not encountered. Excavation refusal on bedrock was encountered at

depths ranging from 0.5 to 10 feet below the existing ground surface. Penetration thicknessesinto the bedrock, except within TP-8 where hard bedrock was encountered at a shallow depth,ranged from 1.5 to 5.0 feet. The soils encountered in Test Pits TP-1 and TP-2 and above thebedrock in the other test pits consisted of up to 3 inches of topsoil (with major roots) overlyingvarious layers of fine/fine to medium sandy clay (CL and CH), silty to clayey fine to coarse sand(SP-SM or SM to SC), and fine to coarse sandy fine and coarse gravel (GP), extending to themaximum depths explored of about 0.5 to 12.0 feet below the existing ground surface. Thesandy clay soils were moist, brown in color, estimated to be medium stiff to stiff, may beexpansive, and are anticipated to exhibit low to moderate strength and low compressibilitycharacteristics under the anticipated loading range. The natural sand/gravel soils were dry tomoist, brown in color, estimated to be medium dense to very dense, and are anticipated to exhibithigh strength and low compressibility characteristics under the anticipated loading range.

The lines designating the interface between soil types on the test pit logs generally representapproximate boundaries. In-situ, the transition between soil types may be gradual.

Groundwater was not encountered in the test pits during excavation operations. Seasonal andlonger-term groundwater fluctuations on the order of 1 to 2 feet are projected, with the highestseasonal levels generally occurring during the late spring and early summer months.

5. DISCUSSIONS AND RECOMMENDATIONS

5.1 SUMMARY OF FINDINGS

The most significant geotechnical aspects of the site are the presence of potentially expansivenatural clay soils and relatively shallow and hard bedrock. Footings and slabs should not beplaced directly on natural clay soils. Excavations into bedrock will be difficult in the north areaof the site (around Test Pit TP-8), and penetrating more than 2 to 4 feet into the bedrock will alsobe difficult in other areas of the site. On the following page is a summary of depths wheretrackhoe refusal in the test pits was encountered.

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Test Pit Depth of Excavation Refusal (feet)

TP-1 (No Refusal)

TP-2 (No Refusal)

TP-3 4.0

TP-4 9.5

TP-5 4.5

TP-6 7.0

TP-7 10.0

TP-8 0.5

The proposed residences may be supported upon conventional spread and continuous wallfoundations placed on suitable natural soils, bedrock, and/or structural fill extending to suitablenatural soils or bedrock.

In the following sections, detailed discussions pertaining to earthwork, foundations, lateralresistance and pressure, floor slabs, subdrains, pavements, and the geoseismic setting of the siteare provided.

5.2 EARTHWORK

5.2.1 Site Preparation

Prior to constructing the foundations for the residence, all surface vegetation, topsoil, root bulbs,sod, rubbish, construction debris, non-engineered fill, and any other deleterious materials fromareas which will ultimately be structurally loaded should be removed. We estimate thatapproximately 3 inches of stripping will be necessary to remove major roots, vegetation, andorganics, except where tree root balls are located, which will require locally deeper excavationsto remove major roots. Vegetation and other deleterious materials should be removed from thesite. Stripped topsoil will be unsuitable for structural fill but may be stockpiled for subsequentlandscaping purposes.

Subsequent to stripping and prior to the placement of floor slabs and/or structural site gradingfill, the exposed subgrade (consisting of disturbed or undisturbed natural soils) must beproofrolled by passing moderate-weight rubber tire-mounted construction equipment over thesurface at least twice. If excessively soft or loose soils are encountered, they must be removed(up to a maximum depth of 2 feet) and replaced with structural fill.

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Following the above operations, structural site grading fill may be placed in areas of theproposed structures. All topsoil, vegetation, and non-engineered fill must be completely removedfrom all foundation areas.

5.2

.2 Excavations

Temporary construction excavations not exceeding 4 feet in depth may be constructed with near-vertical sideslopes. Deeper excavations not exceeding 10 feet in depth within soils may requireflatter sideslopes or shoring and bracing. Some sloughing of the sandy/gravelly soils on the sidesof the excavations is anticipated. Excavations encountering bedrock will likely allow near-vertical sideslopes within the bedrock. Excavation contractors should be made aware thatexcavating into bedrock at this site may be very difficult.

All excavations must be inspected periodically by qualified personnel. If any signs of instabilityor excessive sloughing are noted, immediate remedial action must be initiated.

5.2

.3 Structural Fill

Structural fill is defined as all fill which will ultimately be subjected to structural loadings, suchas imposed by footings, floor slabs, pavements, etc. Structural fill will be required as backfillover foundations and utilities, as site grading fill and, in some areas, replacement fill belowfootings. All structural fill must be free of sod, rubbish, topsoil, frozen soil, and other deleteriousmaterials. Structural site grading fill is defined as fill placed over fairly large open areas to raisethe overall site grade. For structural site grading fill, the maximum particle size should generallynot exceed 4 inches; although, occasional larger particles, not exceeding 8 inches in diameter,may be incorporated if placed randomly in a manner such that "honeycombing" does not occurand the desired degree of compaction can be achieved. The maximum particle size withinstructural fill placed within confined areas should generally be restricted to 2 inches.

The on-site sand/gravel soils at the site may be utilized as structural site grading fill, but the siltyclay soils are not recommended for use in any structural fill situation due to the potential for highplasticity and possible expansive properties. Only granular soils are recommended as structuralfill in confined areas, such as around foundations and within utility trenches. Imported structuralfill should consist of 3-inch maximum size well graded sandy/gravelly material having less than30 percent retained on the 0.75-inch sieve and no more than 20 percent passing the No. 200sieve.

To stabilize soft subgrade conditions, a mixture of coarse gravels and cobbles and/or 1.5- to2

.0-inch gravel (stabilizing fill) should be utilized.

Non-structural site grading fill is defined as all fill material not designated as structural fill andmay consist of any cohesive or granular soils not containing excessive amounts of degradablematerial.

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5.2

.4 Fill Placement and Compaction

All structural fill shall be placed in lifts not exceeding 8 inches in loose thickness. Structural fillsshall be compacted in accordance with the percent of the maximum dry density as determined bythe ASTM

' D-1557 (AASHTO2 T-l 80) compaction criteria in accordance with the table below:

Location

Total Fill Thickness

(feet)Minimum Percentage ofMaximum Dry Density

Beneath an area extendingat least 3 feet beyond theperimeter of the structure 0 to 8 95

Outside area defined above 0 to 5 90

Outside area defined above 5 to 8 95

Pavement granular base/subbbase 95

Structural fills greater than 8 feet thick are not anticipated at the site.

Subsequent to stripping and prior to the placement of structural site grading fill, the subgradeshould be prepared as discussed in Section 5.2.1, Site Preparation, of this report. In confinedareas, subgrade preparation should consist of the removal of all loose or disturbed soils.

If utilized for stabilizing fill, coarse gravel and cobble mixtures should be end-dumped, spread toa maximum loose lift thickness of 15 inches, and compacted by dropping a backhoe bucket ontothe surface continuously at least twice. As an alternative, the fill may be compacted by passingmoderately heavy construction equipment or large self-propelled compaction equipment at leasttwice. Subsequent fill material placed over the coarse gravels and cobbles should be adequatelycompacted so that the "fines" are "worked into" the voids in the underlying coarser gravels andcobbles.

5.2

.5 Utility Trenches

All utility trench backfill material below structurally loaded facilities (flatwork, floor slabs,roads, etc.) should be placed at the same density requirements established for structural fill. Ifthe surface of the backfill becomes disturbed during the course of construction, the backfillshould be proofrolled and/or properly compacted prior to the construction of any exteriorflatwork over a backfilled trench. Proofrolling may be performed by passing moderately loadedrubber tire-mounted construction equipment uniformly over the surface at least twice. If

American Society for Testing and MaterialsAmerican Association of State Highway and Transportation Officials

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excessively loose or soft areas are encountered during proofrolling, they should be removed to amaximum depth of 2 feet below design finish grade and replaced with structural fill.

Most utility companies and City-County governments are now requiring that Type A-l-a/A-l-b(AASHTO Designation - basically granular soils with limited fines) soils be used as backfillover utilities. These organizations are also requiring that in public roadways the backfill overmajor utilities be compacted over the full depth of fill to at least 96 percent of the maximum drydensity as determined by the AASHTO T-180 (ASTMD-1557) method of compaction. Werecommend that as the major utilities continue onto the site that these compaction specificationsare followed.

The natural clay soils at the site are not recommended for use as trench backfill.

5.3 SPREAD AND CONTINUOUS WALL FOUNDATIONS

5.3.1 Design Data

The proposed structure may be supported upon conventional spread and continuous wallfoundations placed on either natural sand/gravel soils, bedrock, or on properly compactedgranular structural fill. Structural fill should extend to suitable natural soils or bedrock andshould not be underlain by sod, rubbish, topsoil, non-engineered fill, disturbed soil, or otherunsatisfactory materials. For design, the following recommended parameters are provided:

Minimum Depth of Embedment for Frost Protection - 30 inches

Minimum Depth of Embedment for Non-frost Conditions - 15 inches

Minimum Width for Continuous Wall Footings - 18 inches

Minimum Width for Isolated Spread Footings - 24 inches

Net Bearing Pressure for Real Load Conditions - 2,500 pounds

The term "net bearing pressure" refers to the pressure imposed by the portion of the structurelocated above lowest adjacent final grade. Therefore, the weight of the footing and backfill tolowest adjacent final grade need not be considered. Real loads are defined as the total of all deadplus frequently applied live loads. Total load includes all dead and live loads, including seismicand wind.

per square foot

Bearing Pressure Increase for Seismic Loading -50 percent

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5.3

.2 Installation

Under no circumstances should the footings be installed on non-engineered fill or upon soft ordisturbed soils, construction debris, frozen soil, or within ponded water.

If the natural granular soils or granular structural fill upon which the footings are to beestablished become disturbed, they should be recompacted to the requirements for structural fillor be removed and replaced with structural fill.

The width of structural replacement fill, where placed below footings, should be extendedlaterally at least 6 inches beyond the edges of the footings in all directions for each foot of fillthickness beneath the footings. For example, if the width of the footing is 2 feet and the thicknessof the structural fill beneath the footing is 1 foot, the width of the structural fill at the base of thefooting excavation would be a total of 3 feet, centered below the footing.

5.3

.3 Settlements

Maximum settlements of foundations designed and installed in accordance withrecommendations presented herein and supporting maximum anticipated loads, as discussed inSection 2, Proposed Construction, are anticipated to be less than one inch.

Approximately 80 percent of the quoted settlement should occur during construction.

5.4 LATERAL RESISTANCE

Lateral loads imposed upon foundations due to wind or seismic forces may be resisted by thedevelopment of passive earth pressures and friction between the base of the footings and thesupporting soils. In determining frictional resistance, a coefficient of 0.45 should be utilized.Passive resistance provided by properly placed and compacted granular structural fill above thewater table may be considered equivalent to a fluid with a density of 350 pounds per cubic foot.

A combination of passive earth resistance and friction may be utilized provided that the frictioncomponent of the total is divided by 1.5.

5.5 LATERAL PRESSURES

The lateral pressure parameters, as presented within this section, assume that the backfill willconsist of a drained granular soil placed and compacted in accordance with the recommendationspresented herein. The lateral pressures imposed upon subgrade facilities will, therefore, bebasically dependent upon the relative rigidity and movement of the backfilled structure. Foractive walls, such as retaining walls which can move outward (away from the backfill), granularbackfill may be considered equivalent to a fluid with a density of 35 pounds per cubic foot incomputing lateral pressures. For more rigid basement walls that are not more than 10 inchesthick and 12 feet or less in height, granular backfill may be considered equivalent to a fluid with

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Mi 1 Istream PropertiesJob No. 1614-001-14


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a density of 45 pounds per cubic foot. For very rigid non-yielding walls, granular backfill shouldbe considered equivalent to a fluid with a density of at least 60 pounds per cubic foot. The abovevalues assume that the surface of the soils slope behind the wall is horizontal, that the granularfill has been placed and lightly compacted, not as a structural fill. If the fill is placed as astructural fill, the values should be increased to 45 pounds per cubic foot, 60 pounds per cubicfoot, and 120 pounds per cubic foot, respectively. If the slope behind the wall is 2 horizontal to1 vertical, the values for purely active walls and basement walls should increase to 57 pounds percubic foot and 67 pounds per cubic foot, respectively.

For seismic loading, a uniform pressure of 150 pounds per square foot should be added.

5.6 FLOOR SLABS

Floor slabs may be established upon suitable undisturbed natural soils, bedrock, and/or uponstructural fill extending to suitable natural soils. Topsoil and natural clay soils are not consideredsuitable. If natural clay soils are exposed as the subgrade for floor slabs, we recommend they beover-excavated at least 12 inches (unless natural sand/gravel soils are encountered first) and re-placed with properly compacted structural fill. To provide a capillary break, it is recommendedthat floor slabs be directly underlain by at least 4 inches of "free-draining" fill, such as "pea"gravel or 0.75- to 1.0-inch minus clean gap-graded gravel. Settlements of lightly to moderatelyloaded floor slabs are anticipated to be minor.

5.7 SUBDRAINS

5.7.1 General

Relatively shallow groundwater was not encountered at this site, but given the relatively shallowdepths of bedrock observed, we recommend that perimeter foundation subdrains be designed andconstructed wherever floor slabs will be placed below bedrock due to the potential for seepageon top of or through the bedrock. Recommendations for subdrains are provided in the nextsubsection.

5.7

.2 Foundation Subdrains

Foundation subdrains should consist of a 4-inch diameter perforated or slotted plastic or PVCpipe enclosed in clean gravel. The invert of a subdrain should be at least 2 feet below the top ofthe lowest adjacent floor slab. The gravel portion of the drain should extend 2 inches laterallyand below the perforated pipe and at least 1 foot above the top of the lowest adjacent floor slab.The gravel zone must be installed immediately adjacent to the perimeter footings and thefoundation walls. To reduce the possibility of plugging, a geotextile, such as Mirafi HON orequivalent, must be placed between the clean gravel and adjacent backfill soils. Prior to theinstallation of the footing subdrain, the below-grade walls should be dampproofed. The slope ofthe subdrain should be at least 0.3 percent. The gravel placed around the drain pipe shouldconsist of clean, 0.75-inch to 1.0-inch minus gap-graded gravel and/or "pea

" gravel. The

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ÿH

foundation subdrains can be discharged into storm drains, a local sump, or other suitable down-gradient location.

5.8 PAVEMENTS

The natural silty/sandy clay soils will exhibit poor pavement support characteristics whensaturated or nearly saturated. Considering the silty clays as the design subgrade soils and theprojected traffic conditions, the following pavement sections are recommended:

Flexible Pavements (Asphalt Concrete):

Residential Streets

(Moderate Volume of Automobiles and Light Truckswith Occasional Medium and Heavy Trucks)

[3 equivalent 18-kip axle loads per day]

3 inches Asphalt concrete

9 inches Aggregate base course

Over Properly prepared subgrade soils (seeSection 5.2.1)

Utilization of a filter fabric, such as Mirafi 500X or equivalent, over soft subgrade may also beadvantageous.

Asphalt concrete and base course components should meet the requirements and be placed inaccordance with the Utah Department of Transportation specifications.

5.9 GEOSEISMIC SETTING

5.9.

1 General

Utah municipalities have adopted the International Building Code (IBC) 2012 and InternationalResidential Code for One- to Two-Family Dwellings 2012. The IBC 2012 code determines theseismic hazard for a site based upon 2008 mapping of bedrock accelerations prepared by theUnited States Geologic Survey (USGS) and the soil site class. The USGS values are presentedon maps incorporated into the IBC code and are also available based on latitude and longitudecoordinates (grid points).

5.9.2 Faulting

Based upon our review of available literature, no active faults are known to pass through orimmediately adjacent to the site. The nearest active fault is the Wasatch Fault, located more than

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18 miles northeast of the site. The Wasatch Fault Zone is considered capable of generatingearthquakes as large as magnitude 7.3

3.

5.9.3 Soil Class

For dynamic structural analysis, the Site Class C - Very Dense Soil and Soft Rock Profile asdefined in Chapter 20 of ASCE 7 (per Section 1613.3.2, Site Class Definitions, of IBC 2012) canbe utilized.

5.9.4 Ground Motions

The IBC 2012 code is based on 2008 USGS mapping, which provides values of short and longperiod accelerations for the Site Class B boundary for the Maximum Considered Earthquake(MCE). This Site Class B boundary represents average bedrock values for the Western UnitedStates and must be corrected for local soil conditions. Accordingly, based on the site latitude andlongitude (40.5211 degrees north and 1 11.3966 degrees west, respectively), the ground motionvalues for this site are a Short Period Map Value (Ss) of 0.60g, a Residential Site Value (Sds) of0

.46g, and a Residential Seismic Design Category ofC.

5.9.5 Liquefaction

Liquefaction is defined as the condition when saturated, loose, finer-grained sand-type soils losetheir support capabilities because of excessive pore water pressure which develops during aseismic event. Given that groundwater was not encountered and relatively shallow bedrock wasencountered at the site, it is our opinion that liquefaction at the site will not likely occur duringthe design seismic event.

5.10 SITE OBSERVATIONS

Prior to placement of foundations, floor slabs, pavements, and site grading fills, a geotechnicalengineer from GSH must verify that suitable subgrade conditions have been exposed.

Arabasz, W.J., Pechmann, J.C., and Brown, E.D., 1992, Observational seismology and theevaluation of earthquake hazards and risk in the Wasatch Front area, Utah, in Gori, P.L., andHays, W.W., eds., Assessment of regional earthquake hazards and risk along the Wasatch Front,Utah: U.S. Geological Survey Professional Paper 1500-D, 36 p.

Page 13



5.11 CLOSURE

If you have any questions or would like to discuss these items further, please feel free to contactus at (801) 685-9190.

Respectfully submitted,

GSH Geotechnical, Inc. A !ÿ0$i°/V4

gf 171715

William G. Turner, P.E.State of Utah No. 171715 %Senior Geotechnical Engineer

w

Reviewed by:

Patrick R. Emery, P.E.State of Utah No. 7941710

Project Geotechnical Engineer

WGT/PRE:jlh

Encl. Figure 1, Vicinity MapFigure 2, Site PlanFigures 3A through 3H, Log of Test PitsFigure 4, Key to Test Pit Log (USCS)

Addressee (email)

cc: Mr. Paul Berg (email)Berg Engineering

Page 14

MILLSTREAM PROPERTIES

JOB NO. 1614-001-14

SCALE IN FEET

1000 0 1000 2000

REFERENCE:

USGS 7.5 MINUTE TOPOGRAPHIC QUADRANGLE MAP(S)ENTITLED "HEBER CITY, UTAH" DATED 1999; "FRANCIS, UTAH"DATED 1997; "CHARLESTON, UTAH" AND "CENTER CREEK, UTAH"BOTH DATED 1998

FIGURE 1

VICINITY MAP

1GBH TEST PIT LOGPa°e: 1 of ,

TEST P,T: TP-1

CLIENT: Millstream Properites PROJECT NUMBER: 1614-001-14

PROJECT: Valley Mills Development DATE STARTED: 4/18/14 DATE FINISHED: 4/18/14

LOCATION: North & West of 1050 North Mill Road. Fleher Cilv. Utah GSM FIELD REP.: HRW

DRILLING METHOD/EQUIPMENT: 325 C, Cat Backhoe HAMMER: WEIGHT: DROP:

GROUNDWATER DEPTH: Not Encountered (4/18/14) ELEVATION:

DESCRIPTION REMARKS

Ground Surface

cU FINE SANDY CLAY

with trace medium sand; major roots (topsoil) to 3", brown

grades with some coarse sand and gravelSM SILTY FINE TO COARSE SAND

with some e-lav: brown

CLAYEY FINE TO MEDIUM SAND

with some silt: brown

SM SILTY FINE TO COARSE SAND

with some clay

CL FINE TO MEDIUM SANDY CLAY

with some sill; brown

End of Exploration at 12.0,No significant sidewall caving.No groundwater encountered ai time of excavation.

94 28

17 S5 25

19

14 20

-10

ÿ20

-25

13

moist

medium stiff

medium dense

moist

moist

medium dense

moisi

medium dense

moist

medium stiff

See Subsurface Conditions section in the report for additional information. FIGURE 3A

TEST PIT LOGPa.ee: I of I

TEST PIT: TP-2

CLIENT: Midstream Properiles PROJECT NUMBER: 1614-001-14

PROJECT: Valley Hills Development DATE STARTED: 4/18/14 DATE FINISHED: 4/18/14

...OCATfON: North & West of 1050 North Mill Road, l-Ieber City, Utah GSH FIELD REP.: 11RW

DRILLING METT10D/EQU1PMENT: 325 C Cat Baekhoe HAMMER: WEIGHT: DROP:

GROUNDWATER DEPTH: Not Encountered (4/18/14) ELEVATION: -

DESCRIPTION REMARKS

Ground Surhicc

FINE TO MRDIUM§SF5Wt®lAVwith same silt

, major roots (topsoil) to 3"

; brown

FINE TO MEDIUM SAND

with some silt; slightly cemented; brown

>rades highly cemented with occasional cobbles and boulders up to1.5, in diameter

grades less cemented and less cobbles and boulders

GP FINE TO t 'OAKS!-. SANDY FINE AND COARSE GRAVE

with some silt; brown

End of Exploration at___ ___ ,

No significant sidewall cavingNo groundwater encountered at time of excavation.

10

15

-20

moist

medium stiff

moist

dense

very dense

slightly moistdense

See Subsurface Conditions section in the report for additional information.FIGURE 3B

CLIENT; Millstream Properties PRO J F.CT N UM B E R; 1614-001-14

PROJECT: Valley Hills Development DATE STARTED: 4/18/14 DATE FINISHED: 4/18/14

LOCA HON: North & West of 1(00 North Mi 1 Road, l lcbcr City. Utah GSH FIELD REP.: HRW

DRILLING iVIETI 10D/EOU!PMLN'I ÿ C'

al linckhoe HAMMER: WEIGHT: DROP:

TEST PIT LOGPaae: 1 of 1

TEST PIT: T.P-3

GROUNDWATER DLP'l 11. Nu! Fnuumlered H; IIT'LI) ELEVATION;

DESCRIPTION REMARKS

Ground Surface

CL S1LTY CLAY

with some fine sand; major roots (topsoil) to 3"; reddish-brown

SANDSTONE

highly fractured; moderately hard; reddish-brown

grades less fractured and hard with depth

Bedrock refusal at 4,0'

No significant sidewall caving,No groundwater encountered at time of excavntio

-10

ÿ15

.20

moist

medium stiff

moderately hard

hard

See Subsurface Conditions section in the report for additional information. FIGURE 3C

SG5H TEST PIT LOGPaae: , of ,

TEST P,T: TP-4

CLIENT': Midstream Propcril.es PROJECT NUMBER: 1614-001-14

PROJECT: Valley Hills Development IUII. STARTED: 4/18/14 DATE FINISHED: 4/18/14

LOCATION: North & West of 1050 North Mill Road. I leber Ciiv, Utah GSM FIELD REP.: HRW

DRILLING METHOD/EQUIPMENT,: 325 C Cat Backhoe HAMMER: WEIGHT: DROP:

GROUNDWATER DEPTH: Not Encountered (4/18/14) ELEVATION:

DESCRIPTION REMARKS

Ground Surface

FINE TO MEDIUM SANDY CLAY

with some silt, major roots (topsoil) to 3" browi:

SM SILTY FINE TO MEDIUM SAND

with some clay; highly cemented to 5'; light brown

grades with less cementation and more reddish-brown

Bedrock refusal at 9,5'

No significant sidewall caving.No groundwater encountered at time of excavation.

12

ÿ4

10

.20

16

moist

medium stiff

moist

dense

See Subsurface Conditions section in the report for additional information. FIGURE 3D

Documents

IVheber-ut.granicus.com/DocumentViewer.php?file=heber-ut_5...Millstream Properties Job No. 1614-001-14 Geotechnical Study May 6, 2014 3. 3.2 Moisture Content and Dry Density Tests