Post-mortem analysis of the embankment failure at Makinohara of Tomei Expressway induced by Surugawan Earthquake (Aug. 2009)

将室内试验数据与现场干密度、含水率进行对比，得出在2009年8月surugawa地震中未破坏的填土体等体积抗剪强度约为1200kpa，而在地震中破坏的填土体，通过反算估计其强度约为120kPa。通过现场的总体观察和对填充物的一系列实验室试验，定量地阐明了在Tomei高速公路Makigahara填充物抗剪强度降低的可能机制，这是由于水的长期渗透造成的。

Comparing the laboratory test data with the in-situ dry density and moisture content, it was concluded that constant volume shear strength of the fill which did not fail during the Surugawan earthquake (Aug. 2009) was about 1,200kPa while the strength of the fill which failed during the earthquake was estimated to be about 120kPa based on the back-calculation. The possible mechanism of this reduction of the shear strength of the fill material, at Makigahara, Tomei Expressway, caused by a long-term infiltration of the water was quantitatively clarified by the overall observation at the site together with a series of laboratory tests on the fill material.