The Virginia Military Institute in Lexington, Virginia wanted to convert an unusable plot of land into a much needed drill field and shooting range complex. The site presented several challenges due to the changing grades and extensive rock blasting and fill areas.
Solution
The deputy director of construction at Virginia Military Institute (VMI) considered several options including poured in place walls and precast concrete blocks systems that needed to be set with a crane. They finally decided to use a segmental block wall system due to its many advantages. The SRW system was far less expensive to install than other options, and the weathered look of the stone matched existing stone used on the campus, providing a rustic fieldstone look.
The retaining walls were built on a crushed gravel leveling pad and reached 34 feet high, extending over a quarter mile long, and holding up over 100,000 cubic yards of fill. The walls were used to create a level 6-acre field. To reinforce the land, Stratagrid SG200 and SG350 soil reinforcement was placed in embedment lengths of 22 feet behind nearly 50,000 square feet of block wall. The geogrid was placed on every other course with 2-inch minus crushed rock used for reinforced backfill.
Why Strata?
“Strata was chosen as the geogrid supplier for several reasons,” said Mark Eckhart of Eckhart Construction, whose company built the wall. In addition to having developed a good working relationship with Strata over the years, other factors that Eckhart considered included that Strata would produce custom-sized, large diameter master rolls of geogrid with widths of 6 and 12 feet. These custom-sized rolls allowed Eckhart to cut the geogrid to the needed lengths with very little waste. "The quantities estimated by Strata are true to the job, and the cost savings really adds up,” said Eckhart. “Strata is a good group and we rely on their engineers and technical support to ensure the job is done most efficiently.”
Results
Today the $17 million complex at VMI includes three drill fields, an obstacle course and firing range with 30 positions. The SRW wall blends beautifully with the natural stone used in the campus and will be enjoyed for generations to come.
For more information about geogrid reinforcement, visit Strata www.geogrid.com or call 800.680.7750.
PROJECT DETAILS
General Contractor: Branch & Associates, Inc., Roanoke, VA
Wall Subcontractor: Eckhart Construction Services, Inc., Ft. Mill, SC
Architect: Clark Nexen, Roanoke, VA
Civil Engineer: Draper Aden Associates, Blacksburg, VA
SRW Producer: Chandler Concrete, Inc., Christiansburg, VA
SRW Licensor: VERSA-LOK Retaining Wall Systems
Geosynthetic Supplier: Strata Systems
