A Fundamental Study on Stability Analyses of Soft Clay Subjected to Embankment Loading

本研究的目的是检查的有效性，目前可用的稳定性分析的基础上，精确的模型试验，使用土工离心机。在正常固结粘土地基上进行了模型路堤的空中施工，并对破坏机理进行了仔细的研究。本研究特别考虑了地表不排水抗剪强度的大小，并得出以下结论.正常固结粘土地基的破坏是渐进式的，初始破坏发生在近地表强度较低的区域.当边坡即将发生破坏时，边坡下方区域的孔隙水压力将急剧降低.基于K_0三轴强度的总应力分析虽然低估了安全系数，但能准确地预测破坏面的位置。有效应力分析只有在准确知道土中孔隙水压力的情况下才能给出合理的预测.柴田和关口提出的失效预测方法对快速构造的构件是有效的。

The purpose of this study Is to examine the validity of currently available stability analyses on the basis of accurate model tests using a geotechnical centrifuge. In-flight construction of a model embankment was carried out on normally-consolidated clay ground and the mechanism of failure was carefully studied. A parameter particularly considered in this study was the magnitude of undrained shear strength at the surface of the ground.Conclusions drawn from this study are as follows.1. The failure of normally-consolidated clay ground is of a progressive type with initial failure taking place in the areas near the surface where the strength is relatively low.2. Sharp reduction of pore pressures takes place in the areas beneath a slope when failure is about to occur.3. Total stress analyses based on K_0 triaxial strength predict the location of the failure surface accurately, although they underestimate the safety factor. Effective stress analyses give reasonable prediction only when pore pressures in clay are accurately known.4. The method of failure prediction proposed by Shibata and Sekiguchi Is valid for rapidly-constructed embankments.