Shaking Table Tests and Circular Arc Analysis for Large Models of Embankments on Saturated Sand Layers

Abstract

The seismic stability of an embankment resting on saturated sand layers was studied by carrying out shaking table tests using large models. This paper is concerned with the failure mode of embankments during earthquakes ; the slope stability analysis method used here is based on the assumption of failure along a circular arc (Circular Arc Analysis). For each test a large model of an embankment on a saturated sand layer was placed in a shaking table box (8 m in length, 4 m in width and 2 m in height). The failure of the embankment was investigated by measuring the rapid rapid increase in residual settlement and lateral displacement in accordance with the increase in table acceleration. The pore pressure ratio was found to be greater than 0.5 when significant settlement and lateral displacement of the embankment took place, and the failure plane was determined by locating the breaks in the horizontal white sand layers (5 mm in thickness) in a cross-section of the embankment. The test results were in good agreement with the results calculated by a method of circular arc analysis which takes into account the effects of the seismic forces and the excess pore pressures. It was concluded that the stability of embankments on saturated sand layers during earthquakes can be evaluated by using this type of circular arc analysis method.