USING GEOSYNTHETICS TO REDUCE SURCHARGE-INDUCED STRESSES ON RIGID EARTH-RETAINING STRUCTURES

Results of a finite-element study are presented that indicate that it is possible to achieve significant reductions in surcharge-induced horizontal stresses on rigid earth-retaining structures (retaining walls, bridge abutments, etc.). This is achieved by using a new type of geosynthetic, called a geoinclusion, that is placed between the structure and retained soil. The geoinclusion functions as a relatively compressible inclusion that allows the retained soil to undergo controlled yielding to mobilize its inherent strength. In doing so, the soil resists a significant portion of the surcharge-induced stress increment rather than merely transmitting it to the wall. If, in addition to the geoinclusion, relatively stiff tensile reinforcement such as polymer geogrid or steel is placed within the retained soil, even greater reductions in surcharge-induced horizontal stresses can be achieved. These conclusions are consistent with previous studies that included both finite-element modeling and physical testing of the use of geoinclusions, either alone or with tensile reinforcement, under gravity-induced earth loads only.