This paper reports the seismic responses of geosynthetically reinforced walls with two types of backfills using shake table tests. The backfills are tire-derived aggregates (TDA) and poorly graded sand, respectively. Mechanically stabilized earth (MSE) walls with reinforced TDA backfill have not been fully tested under seismic conditions. In this study, two geosynthetically reinforced walls are tested on a one-dimensional shake table. A section of reduced-scale MSE wall (1.6 m high, 1.5 m deep, and 1.5 m long) is built in a box that is anchored on a shake table that can generate earthquake excitations obtained from actual field recordings. Layers of geogrid are used as reinforcement. The geosynthetic reinforcement is based on static external and internal stability design. In each test, the segmental MSE wall is instrumented with accelerometers, linear variable differential transformers, linear potentiometers, and dynamic soil stress gauges to record the accelerations, wall vertical deformations, horizontal deflections of the wall face, and transient effective stresses during the shaking, respectively. The experimental study reveals the advantageous seismic performances of a geosynthetically reforced wall with TDA backfill over an MSE wall using traditional granular backfill.

The purpose of this study is to understand the seismic responses of slurry walls. Slurry walls have been widely used as seepage barriers in levees, but their behavior under seismic forces is relatively unknown. The types of walls that are evaluated in this research include cementbentonite (CB) and soil-cement-bentonite (SCB). A slurry wall with the following dimensions 150cm × 160cm × 20cm is constructed and tested on a 2.4 m × 2.1 m one dimensional shake table that is capable of replicating the 6.7 magnitude Northridge earthquake. The load capacity of the table is 20.0 tons (177.9 kN) and the actuator provides 245 kN hydraulic fluid driving force through a 25 cm displacement stroke. A 150cm × 187cm × 180cm rigid steel-frame box that is anchored on the shake table contains the slurry wall and the sandy soil that is compacted on both sides of the wall to simulate a levee section. In each shake table test, the slurry wall and the confining soil are instrumented with accelerometers, LVDT transducers, linear potentiometers, and dynamic soil stress gauges to respectively record the accelerations, vertical and horizontal deformations of the wall, and transient dynamic soil pressures on the wall during the simulated earthquake excitations. After the test, the soil is removed so that the slurry wall can be examined for any cracks that are caused by the shaking. Furthermore, samples are taken at 40 cm from the top and the bottom of the wall. Triaxial compression tests along with flexible wall permeability tests are conducted to reveal the possible micro cracks that could be caused by the shaking. The experimental results reveal the during-and post-earthquake performances of the slurry walls, so that adequate remediation measures can be taken.