|StoneWall Select: Installation
Constructing Taller Walls
(above three feet)
Thanks to its installation flexibility and well-engineered design, StoneWall SELECT lends itself well to the construction of tall or terraced walls. In fact, with geogrid soil reinforcements properly installed, StoneWall SELECT heights can safely soar as high as 40 feet. However, it is very important to check the global stability of the site before constructing any retaining wall.
For walls exposed 3 feet or more you must terrace the wall or use geogrid soil reinforcing.
A. Terracing Walls
Terracing walls provides an attractive appearance. However there are some limitations. Terraced walls significantly increase the time spent on base preparation. Terraced walls also require substantial space. If a tiered retaining wall is placed within a horizontal distance less than twice the height of the bottom wall, a surcharge will be applied to the bottom wall. If a surcharge is applied, additional soil stabilization and reinforcement with geogrids will be required. However if there is plenty of space to allow for terracing, it will create a beautiful result (see illustration).
Terrace Wall, Section View
B. Geogrid Soil Reinforcing
Geogrid provides strength to the soil in the same way that reinforcing steel strengthens concrete. When properly engineered and installed, the reinforced soil section, which is the combination of the StoneWall SELECT facia and the reinforced soil, will resist forces applied by the retained soil and surcharges on that soil. The geogrid layers fit between courses of StoneWall SELECT units and are secured to the wall by the friction between the units, the interlocking clips and the granular fill placed from core to core in the StoneWall SELECT units. Always refer to geogrid manufacturers' information for proper use of their respective products.
Geogrid Placement for walls above 3 feet, Section View
The following procedure should be followed when installing geogrid in a StoneWall SELECT wall.
- Place and compact granular fill within and behind the StoneWall SELECT units.
- Place and compact soil behind the granular fill in the reinforced zone.
- Clean off any loose material from the top of the StoneWall SELECT units.
- Cut the geogrid to the proper length as specified in the drawings and/or geogrid tables.
Geogrid Placement for walls above 3 feet, Detail, Plan View
- Place the grid to the front of the StoneWall SELECT units making sure that the strength direction of the grid is perpendicular to the wall.
- Install the interlocking clips. Lay another course of StoneWall SELECT units. Repeat steps 1 & 2.
- Tension the grid before and during backfill placement.
- Execute compaction to 95% of maximum density after 8 " of backfill has been placed
- Place additional geogrid lengths at required vertical elevations by repeating steps 1-8.
- Use only light weight, hand operated compaction equipment within 3 feet of the StoneWall SELECT units.
Geogrid Tables for use with StoneWall SELECT units are provided separately and not included in this manual. Please contact your local StoneWall SELECT representative for this information.
Geogrid Placement for walls above 3 feet, Detail, Section View