Speed, cost, safety. Those are the top three reasons engineers and contractors typically cite for going with Gravix precast concrete wall systems when earth retention is needed on a project. Designed for challenging commercial jobs, heavy rail applications, and Department of Transportation demands, Gravix eliminates the need for temporary shoring, provides a safer slope backcut, and reduces infill stone volume. It’s currently used by 40 DOTs across the United States.
There are many other reasons to go with Gravix. In Lockeford, California, the local Jensen Precast facility needed to add a new drycast batch plant to keep up with increasing demand for its underground infrastructure products. The team there knew a thing or two about the benefits of Gravix. Jensen Precast has been a licensed manufacturer of the retaining wall system for years.
Project Owner: Jensen Precast
Engineer: Arshad Vali, S.E.
Contractor: Mid-Cal Constructors Inc.
Product: Gravix MSE Wall System
Planning for the new drycast plant included a drive over grizzly for the delivery of aggregates to supply sand and gravel. The above ground delivery system required a ramp with a 6 degree slope on both sides of the discharge area with stabilizing walls on either side. The walls would taper from 2’ high at the ends to 15’ at the center and stretch 137’ on either side of the grizzly, which would be located at the 15’ center elevation.
Keeping the aggregate receiving area above ground improves safety, cuts delivery time, and enables the aggregates to be discharged to an automated conveyor line. The rock and sand are transported to storage bins, saving labor and maintaining critical driving lanes for product movement.
PRECAST VS CAST-IN-PLACE
After considering cast-in-place walls, Jensen Precast Engineer Arshad Vali and Project Manager Cy Thompson decided a better solution could be found right inside the Lockeford facility where Gravix MSE Wall products are manufactured. It proved to be an optimal decision.
“We originally designed it with cast-in-place walls on either side,” Vali explains. “But because of the ramp height, the cost of cast-in-place turned out to be quite expensive. So we decided to use the Gravix MSE Wall System, a mechanically stabilized earth wall with a T-shaped tieback.”
The standard Gravix wall component has a face of 32 square feet (8’L x 4’H). Each unit incorporates a triangular section in the stem perpendicular to the face, which allows the weight of the backfill to bear on the units below and transfer downward pressure, resulting in a stabilizing effect.
Scott Paris, Project Contractor with Mid-Cal Constructors in Stockton, California, says the Lockeford project won him over to using Gravix, noting that the system requires precision casting and setting of the base course.
“It took a little bit of getting used to, but overall it is a fairly innovative system,” Paris says. “The benefits of the Gravix MSE Wall are speed, overall cost of construction, and safety. Now that I have finished the project and have all the bugs out, I would definitely recommend Gravix over cast-in-place.”
- Once site preparation is complete, Gravix MSE Wall products install more quickly and with less labor on the jobsite compared to cast-in-place
- Since Gravix Walls are precast concrete, there is no waiting for concrete to cure on the jobsite and no weather delays
- Manufactured in a controlled environment by precast concrete specialists, Gravix Walls are quality assured, accepted by most DOTs and conform to AASHTO bin wall design methodology