花岗岩残积土抗拉强度试验研究  

Experimental Study on Tensile Strength of Granite Residual Soil

作　　者：汤连生[1] 桑海涛[2,3] 侯涛 宋晶[1,3] 罗珍贵 陈浩昆[1,3] 

机构地区：[1]中山大学地球科学与地质工程学院,广东广州510275 [2]中山大学工学院,广东广州510275 [3]广东省地质过程与矿产资源探查重点实验室,广东广州510275 [4]广东省工程勘察院,广东广州510510

出　　处：《中山大学学报（自然科学版）》2014年第6期98-105,共8页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国家自然科学基金资助项目(40872205);全国高等学校博士学科专项科研基金资助项目(20120171110031);广东省自然科学基金资助项目(07003738);广东省科技计划资助项目(2008B030303009)

摘　　要：在传统工程地质环境及土力学性质的研究中,土体的抗拉强度常常被忽略,而其实抗拉张强度在评估非饱和红土的崩岗、崩塌及土坝、堤防、路基、垃圾填埋场等边坡的稳定性方面,起着决定性的作用。文章利用自行研制的土体单轴抗拉强度试验仪,对华南地区广泛分布的两种花岗岩残积土的抗拉强度进行了试验研究,同时通过快剪试验得到了黏性花岗岩残积土的抗剪强度参数,并对花岗岩残积土的抗拉强度机理进行了分析。试验结果表明,花岗岩残积土抗拉强度与含水量呈负相关关系,并且随着含水量的增大,抗拉强度的减小幅度会随干密度大而增大;抗拉强度与干密度呈正相关关系,并且随着干密度的增大,抗拉强度的增大幅度会随含水率增大而增大;砂质花岗岩残积土(粉黏土质砂)的抗拉强度普遍低于黏性花岗岩残积土(含砂黏土)的抗拉强度;黏性花岗岩残积土(含砂黏土)的抗拉强度与其粘聚力呈正相关关系,与内摩擦角相关性不大。花岗岩残积土的抗拉强度机理分析表明,土颗粒间的联结作用力是土体抗拉强度主要来源,包括土颗粒间的直接接触联结作用力、土颗粒间的微观非接触联结作用力和通过胶结物或气液收缩膜作用产生的间接接触联结作用力。Tensile strength is often ignored in traditional research of engineering geology and soil me-chanics,however,tensile strength plays a critical role in the stability assessment of red soil collapse,soil dam,embank ment,subgrade and rubbish buried field.The tensile strength test apparatus developed by authors is used to explore two types of granite residual soil existing widely in South China,and shear strength parameters of cohesive granite residual soil are obtained through direct shear test,then the mech-anism of granite residual soil’s tensile strength is analysed.The results show that granite residual soil’s tensile strength increases with the rising water content and dry unit weight,however the range becomes less with the rising dry unit weight and water content;the tensile of sandy granite residual soil is usually lower than that of cohesive granite residual soil,and cohesive granite residual soil’s tensile strength in-creases with cohesion,but has little relation with angle of internal friction.The analysis of granite residu-al soil’s tensile strength indicates that joining forces between soil particles are the main source of tensile strength,which includes joining forces with direct contact,microcosmic joining force without direct con-tact,and joining force aroused through cement or Gas-Liquid shrink film.

关 键 词：花岗岩残积土 抗拉强度 单轴抗拉强度试验仪 抗拉强度机理 

分 类 号：TU432[建筑科学—岩土工程] TU411[建筑科学—土工工程]