香港大屿山残坡积土的残余强度试验研究

THE DRAINED RESIDUAL STRENGTH OF VOLCANICS DERIVED SOIL SAMPLED ON LANTAU ISLAND, HONGKONG

粘性土的残余强度是边坡稳定性评价、桩基与土的相互作用机理研究及填土边坡设计中的重要参数。本文在综述大量文献的基础上，结合香港大屿山火山岩风化残坡积土的残余强度试验研究，分析了残余强度的测试方法和影响残余强度的因素。研究结果表明，残余强度与有效法向应力间具有明显的非线性关系；与单剪测试结果相比，多级剪测试结果明显偏高。

The knowledge of drained residual strength of cohesive soils is essential to the geotechnical engineer involved in handling landslide, slope stability, embankment design, and interaction of pile with foundation soil. This paper presents a review on measuring methods for residual strength and factors influencing residual strength of cohesive soils. Drained residual shear tests of volcanics derived soil sampled in Lantau Island of Hong Kong are performed on Bromhead ringshear apparatus. The results of investigations exhibit a nonlinear relation between residual strength and effective normal stress. A comparison of residual strength obtained by the single stage shearing with that by the multistage shearingindicates that the multistage shearing may give erroneous results due to lateralwall friction resulting from excessive settlement of soil sample during consolidation and shearing.