含石量、粗颗粒级配与细粒土性质对土石混合体剪切特性影响研究  

Effect of rock content,coarse-grained gradation,and fine-grained soil properties on the shear characteristics of soil-rock mixtures

作　　者：龚健 梁桓玮 王剑峰 王展宏 许海 欧孝夺[2] 罗月静 GONG Jian;LIANG Huanwei;WANG Jianfeng;WANG Zhanhong;XU Hai;OU Xiaoduo;LUO Yuejing(Guangxi Hualan Geotechnical Engineering Co.,Ltd.,Nanning 530004,China;School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;China Railway Nanning Group Co.,Ltd.,Nanning 530029,China)

机构地区：[1]广西华蓝岩土工程有限公司,广西南宁530004 [2]广西大学土木建筑工程学院,广西南宁530004 [3]中国铁路南宁局集团有限公司,广西南宁530029

出　　处：《广西大学学报(自然科学版)》2024年第6期1244-1258,共15页Journal of Guangxi University(Natural Science Edition)

基　　金：国家自然科学基金项目(52368045);广西科技基地与人才专项(2021AC19244)。

摘　　要：为了研究土石混合体的剪切特性,通过室内大型直剪试验,研究了4种粗颗粒级配、6种含石量(0、20%、40%、60%、80%、100%)和2种细粒土性质对土石混合体剪切特性的影响。研究结果表明:①根据细粒土性质的不同,土石混合体剪应力剪切位移曲线出现应力软化与应力硬化2种特征。②土石混合体的峰值抗剪强度随着含石量和上覆荷载增加而增加。细粒土性质主要影响峰值抗剪强度的增长模式——当细粒土为红黏土时,峰值抗剪强度随含石量增加呈明显的线性增长;细粒土为石英砂时,峰值抗剪强度则呈台阶状增长趋势。粗颗粒级配对峰值抗剪强度的影响较小。③土石混合体的内摩擦角受含石量、粗颗粒级配和细粒土性质影响的变化趋势与峰值抗剪强度基本一致,黏聚力随含石量增大和级配跨度的增加逐渐减弱,并结合以往研究建立黏聚力预测公式。In order to study the shear characteristcs of soil-rock mixtures,the effects of four types of coarse-grained gradation,six levels of rock content(0,20%,40%,60%,80%,100%),and two types of fine-grained soil on the shear characteristics of soil-rock mixtures were investigated by means of indoor large-scale straight shear tests.The findings reveal that:①the shear stress shear displacement curve of the soil-rock mixture exhibits two distinct behaviors:stress softening and stress hardening,depending on the type of fine-grained soil.②Peak shear strength of soil-rock mixtures increases with higher rock content and vertical stress.The fine-grained soil type significantly influences the growth pattern of peak shear strength.When red clay is present,peak shear strength shows a clear linear increase with rising rock content.In contrast,when quartz sand is present,the peak shear strength follows a stepped-shaped growth pattern.Coarse-grained gradation has a relatively minor effect on peak shear strength.③The internal friction angle of the soil-rock mixture,influenced by rock content,coarse-grained gradation,and fine-grained soil properties,generally mirrors the trend of peak shear strength.Cohesion decreases as rock content increases and gradation range increases.A prediction formula for cohesion has been developed based on previous studies.

关 键 词：土石混合体 直剪试验 含石量 级配跨度 细粒土 

分 类 号：TU458[建筑科学—岩土工程]