Improved shake table tests on the seismic performance of slurry walls

Slurry walls have been widely used for retrofitting earthen dams and levees. Slurry wall properties, such as strengths and permeability are well known, but there is very little research on their seismic performance. This research includes shake table testing of two common types of slurry walls: sand-cement-bentonite (SCB), and cement-bentonite (CB) walls. Reduced-scale slurry walls with dimensions of 150 cm (long) x 160 cm (tall) x 20 cm (thick) were constructed inside a rigid, steel box that was mounted on top of a shake table. Boundary conditions in the shake table tests were addressed; and dynamic scaling laws were followed to scale the seismic motions. Specimens were tested under two seismic excitations: modified Loma Prieta earthquake motions and sinusoidal sweep frequency motions from 0.20 Hz to 6 Hz. Accelerations, horizontal deflections, dynamic vertical deformations, and dynamic soil pressures were recorded using accelerometers, linear potentiometers, linear variable differential transducers, and stress cells, respectively. The walls were inspected for damages after testing. Unconfined compression tests were performed on slurry wall specimens to further evaluate the effects of seismic stresses on the strengths of slurry walls. The test results revealed the seismic responses and failure mechanisms of slurry walls under seismic events.