Tensar - Westminster Levee

Using Tensar to build over soft soils - Westminster Levee
Multiple layers of uniaxial geogrid were used to reinforce a ten-foot high hurricane protection levee built on the west bank of the Mississippi River to protect a subdivision in the City of Marreno. A full-scale test section was first constructed to verify the design. The test section was fully instrumented with settlement plates, piezometers, slope inclinometers and strain gauges attached to the reinforcing geogrids. Following the success of the test section, the one mile long hurricane levee was completed in 1988. The levee was built over fifty to sixty feet of very soft-to-soft compressible clays common to the New Orleans area. Shear strength of the clays was approximately 150 psf for the first twenty feet of depth followed by a linear increase in shear strength for the next thirty-five feet of depth to a final value of 400 psf at elevation -55. This project demonstrated the validity of horizontal reinforcement in reducing the cross sectional width of the proposed levee from 224 feet to 136 feet, a 40% reduction in the levee footprint.