Full-Scale Testing of a Shored Mechanically-Stabilized Earth (SMSE) Wall Employing Short Reinforcements

Abstract

Mechanically stabilized earth (MSE) walls are frequently constructed to accommodate widening of existing roads or construction of new roadways in steep terrain. Because substantial excavation must be performed to establish a flat bench upon which to construct the MSE wall, unshored construction may not be feasible. Therefore, a shoring wall is often constructed to stabilize the backslope to facilitate MSE wall construction. Full-scale testing was conducted to examine two hypotheses with regard to shored mechanically stabilized earth (SMSE) walls: (1) construction of an MSE wall in front of a rigid backslope (i.e., shoring system) results in reduced external lateral loading on the MSE wall compared to a conventional MSE wall; and (2) full connection of the MSE reinforcements to the shoring wall provides limited benefit. The full-scale test model was constructed using short geosynthetic reinforcements, ranging in length from 25 to 39 percent of the wall height. The test model was equipped with strain gages, pressure cells (horizontal and vertical), linear variable displacement transducers (LVDT), potentiometers, and inclinometers, as well as surveyed using optical methods. The test wall was extremely stable, even under unrealistically high footing surcharge loads, i.e. 10 times the normal traffic loading. Interpretation of the instrumentation data yielded significant results regarding potential arching effects, internal wall pressures, and reinforcement strains.