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.
作者
龚健
梁桓玮
王剑峰
王展宏
许海
欧孝夺
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)
出处
《广西大学学报(自然科学版)》
北大核心
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)。
关键词
土石混合体
直剪试验
含石量
级配跨度
细粒土
soil-rock mixture
direct shear test
rock content
grade span
fine-grained soil
作者简介
通信作者:龚健(1985-),男,湖北荆州人,副教授,博士,E-mail:jiangong@gxu.edu.cn。
