高液限花岗岩残积土广泛分布于华南地区,针对其中的含粗粒细粒土进行了物理特性和剪切强度特征的试验研究,包括土的组成和微观结构、土的物理状态、土的峰值强度和残余强度等。基于试验结果分析了细粒含水率及对土体物理状态的影响,归纳了土中粗粒含量与天然含水率之间、土的天然状态指标与抗剪强度参数之间的统计规律,探讨了应用反复剪切试验方法确定此类土残余强度的注意事项及大剪切位移时的剪应力特征。由于此类残积土具有高液限土和粗粒土的综合特征,因而需基于粗粒含量的影响来认识有关基本特性。
High liquid limit granite residual soil(GRH) is widely distributed over South China.The physical properties and shear strength characteristics of the fine grained soil containing coarse of GRH are studied,including the natural components and soil fabric,physical features and indexes,shear peak strength and residual strength,etc.Based on a series of laboratory tests,the fine grain moisture content and its influences on liquidity index are analyzed,and the statistic relationships between coarse-grain content and field moisture as well as the physical indexes and shear strength parameters are also generalized.Through repeated direct shear tests,the major points for determining the residual strength by such test methods are discussed,and correspondingly,the typical shear curves of resistance at relatively large shear displacement are analyzed.The residual soil has combinational characteristics of both high liquid limit soil and coarse-grained soil,so it is important to understand its basic properties by studying the effects of coarse grain content.