Installation Tips and Guide.

V 2.1

PATENTS PENDING

Copyright 11/2007. Northstar Vinyl Products, LLC. All Rights Reserved.

IMPORTANT NOTICE This Guide is purposely intended to be general in scope. It is meant to educate a sophisticated user and builder of retaining walls on the finer points of constructing a sheet pile retaining wall using the AquaTerra System which feature Northstar Synthetic Sheet Piling. This Guide does not contemplate every condition that may be encountered, but rather serves as a baseline for understanding the construction methodology. Inexperienced users are highly encouraged to gain a thorough understanding of soils and the backfill compaction process before attempting to build a retaining wall. No warranty, either expressed or implied, is made herein to the suitability of this system or its individual components for your project. Always defer to the recommendations of the engineer of record, as this individual will have a more complete understanding of specific site conditions that may affect the application. Some of the techniques herein are considered the intellectual property of Northstar Vinyl Products, LLC and/or Tensar International Corporation and may not be duplicated. Northstar Vinyl Products, LLC and The Tensar International Corporation offer technical support and can also arrange to provide you with signed and sealed engineering drawings for your project. If you are interested in this support, please contact your Northstar or Tensar Representative. NOTE: One feature of the AquaTerra System is that Northstar’s sheet piling can either be driven

into soil or set in a trench. This Guide instructs on methods using a trench.

PHASES OF CONSTRUCTION

• Trenching • Setting Driving Guide

• Preparing the AquaTerra GridSpines and Setting Sheet Piling

• Preparing and Installing the Geogrid Reinforcements

• Backfilling

• Photo Gallery

TRENCHING Using conventional trenching equipment and methods, prepared a trench at least 12” in width and to a depth required by the engineer. The wall line is along the front “finished” wall of the trench. When digging the trench, attempt to maintain grade. Check the grade. Use crusher run or other similar material to level the trench. You are now ready to set Driving Guide into place. SETTING THE DRIVING GUIDE The installation of the driving guide is a very important step in the process of installing an AquaTerra wall. Once it is in place, setting the panels is extremely efficient. Northstar has devised an innovative and proprietary method for installing the sheet piling and maintaining a positive batter in the wall. Although many of the components are available locally, if needed, Northstar can supply the components of the driving guide. The Driving Guide is made up of upright poles, Outriggers, Staging Arm, and Battering Braces. (Figs 1 and 1.1)

The driving guide is temporary and mobile. As you complete sections of the wall, you can move the guide to the next location. Northstar suggests that you have enough driving guide on hand to build at least 100 feet of driving guide at a time, as building in 100-foot increments is an economical practice.

1. Install the Uprights (3” steel pipes) on 12’ centers on the “finished” side of the trench wall. The placement of the uprights should be approximately 10” from the trench wall and should be embedded 50% deeper than the trench. Additional embedment is required if the soil is weak. (Fig. 2)

Fig 2 Install Uprights forward of the trench wall. Fig 1. The Outrigger Attachment and Upright

pole.

Fig 1.1. The Battering Brace attaches quickly to the Outrigger.

2. Attach the Staging Arm on the Uprights. The Staging Arms are nothing more than a beam where sheet piling “rest” after they are installed in the trench. While the sheet pilings are in a temporary position against the Staging Arms, they in a slight negative batter position. (Fig 3.)

3. Install an Outrigger on each Upright. An Outrigger has two components - an Adjustment Arm (Fig 1) and a Batter Brace (Fig 10). The Adjustment Arm allows you to set a predetermined batter in the sheet piling. The Batter Brace will hold the panels in an unfettered battered position as you backfill the wall. (Fig 4)

Fig 4. Install the Outriggers.

PREPARING THE AQUATERRA GRIDSPINE AND SETTING THE SHEET PILING Sheet piling is a very popular construction item in the marine and heavy construction industries. Long sections of sheet piling are hoisted and set into driving position using cranes or long-reach excavators. Many landscape contractors who are accustomed to installing segmental block walls do not own or have access to this type of equipment and for this reason may be wary of installing long sections of sheet piling. The AquaTerra System was designed to alleviate the need for cranes and long-reach excavators. By design, sheet piling used in an AquaTerra wall are about 45% shorter than sheet piling that has to be driven in similar applications. This benefit alone reduces equipment requirements on a project. In addition, if you have a bucket lift, the AquaTerra system eliminates the need for having to lift the sheet piling above previously installed panels in order to thread them together. Here’s how to prepare the GridSpines and set the sheet piling:

Preparing the GridSpines: 1. Using a 1” drill bit, drill each

GridSpine 1’ from each end. (Fig 5)

Fig 3. Install the Staging Arms.

Fig. 5 Drill GridSpines 1’ from each end.

Setting the Sheet Piling: Using a Bucket Lift:

1. Place two sheet piles adjacent to one another in the trench and allow them to rest against the Staging Arm. (Fig 6)

2. Insert an AquaTerra GridSpine,

interlocking the two panels together. The GridSpine will slide easily down to the bottom of the trench.

3. Insert a composite rod into the

lower and upper holes in the GridSpine. 4. Install the next pair of sheet piling in

a similar manner. 5. Check to make sure the sheet piles

are plumb and in alignment with each other.

6. Slide the composite rods through the adjacent GridSpines, locking all the panels together in one unit (Fig. 8)

7. Repeat until you reach the end of

your Driving Guide (Fig. 9)

Fig 6. Align first two sheets against Staging Arm.

Fig 7. Insert GridSpine to join panels.

Fig 8. Insert composite rod through the upper and lower holes.

Fig 9. All sheets are in place and resting along the Staging Arm.

8. Determine the adjustment to be

made to the Adjustment Arms on the Outriggers to attain the proper starting batter. Adjust the Batter Braces and tighten them to the Outrigger. (Figs 10 & 11).

9. Once the Outriggers are in position

and Batter Braces are fixed, carefully lean the sheet piling away from the Staging Arm towards’ the Batter Braces on the Outrigger. The entire unit of sheet piling should come to rest against the Batter Braces, in their batter position (Fig. 11).

10. In six to ten foot increments, fill the

trench with stone, alternating the fill from back to front. Pay close attention to insure that the toe of the wall does not move during this process. You are now ready to install the geogrid reinforcements. PREPARING AND INSTALLING THE GEOGRID REINFORCEMENTS It is recommended that geogrid reinforcements be attached to the sheet pile wall using a Tensar Bodkin connection. A Bodkin connector (shown below) is a plastic strip that provides a mechanical connection to the sheet pile wall.

Begin by marking (with spray paint) a line across the backs of the sheet piling where each grid course is located.

Fig 11. Sheet piling is now ready to be placed in final position.

Fig 11. Sheet Piling is laid back against the Batter Braces.

Fig 10. Fix the Batter Brace to Outrigger based on predetermined batter.

Using a 1” drill bit, drill each GridSpine as close to the spine’s “bulb” as possible. You may want to drill several grid course locations at one time. Attach the geogrid sections to the wall on the immediate “working” course. Using a pitchfork or other type of tool, tension the geogrid and apply approximately one yard of fill on the grid while it is tensioned. You can then remove the pitchfork and repeat the process on the adjacent geogrid section. Once all geogrid sections along the working course are in place, you can now begin backfilling. BACKFILLING Obtaining the proper soil compaction is perhaps the most important aspect for successful retaining wall construction. If this is your first soil-reinforced wall, be sure to have expert advice and follow proper instructions and procedures. Because there is comprehensive data available from Tensar and other industry publications, a discussion on proper backfill techniques is not part of this Guide. However, because AquaTerra is a unique system, here are a few considerations:

• To insure proper tensioning in the geogrid, always start the backfilling process by placing the soil backfill 3 feet from the back face of the wall

and “rake” the soil towards’ the ends of the reinforcements.

• Once the soil backfill has been placed, 12” of stone should be placed behind the wall to obtain needed compaction and adequate drainage during heavy rain events.

• Though distances between the grid courses may be greater, backfill in uniform 1’ lifts.

• Do not operate heavy compaction equipment within three feet of the sheet piling.

• Compact within three feet of the wall using handheld compaction equipment.

• After each lift, inspect the battered position of the wall. Eventually, the sheet piles should begin to move away from the Batter Brace. You should not see much movement from backfilling the lower courses, but may see some movement as you approach the top elevation of the wall.

• After each lift, inspect the toe of the wall to insure it has not moved.

• If there is movement at the toe, stop the process and contact your engineer for instructions.

TIP: For a quick geogrid installation, you can precut the geogrid sections and install the Bodkin connection, leaving a loop in the end of the geogrid section. That section of grid can then be brought to the site, pushed against the sheet pile and the connector rod slipped through the loop in the geogrid.

A 14’ wall using lightweight vinyl has zero deflection after being backfilled with native Alabama clay.

GALLERY

For More Information Contact:

Northstar Vinyl Products, LLC 770.794.1101

www.northstarvinyl.com

Tensar International Corporation 404.250.1290

www.tensarcorp.com

COPYRIGHT 2007. Northstar Vinyl Products, LLC. All Rights Reserved. Tensar and Bodkin connectors are registered trademarks of Tensar International Corporation.