冻融循环条件下黏土抗剪强度试验研究  

Experimental Study on Shear Strength of Clay under Freeze-Thaw Cycles

作　　者：王永辉 WANG Yonghui(China Railway 14th Bureau Group Second Engineering Co.,Ltd.,Taian 271000,Shandong,China;Department of Civil and Environmental Engineering,Shantou University,Shantou 515063,Guangdong,China)

机构地区：[1]中铁十四局集团第二工程有限公司,山东泰安271000 [2]汕头大学土木与环境工程系,广东汕头515063

出　　处：《路基工程》2025年第2期57-62,共6页Subgrade Engineering

基　　金：国家自然科学基金项目(51878657);广东省自然科学基金项目(2022A1515011200);广东省科技计划项目(STKJ2021129);深部岩土力学与地下工程国家重点实验室开放基金课题项目(SKLGDUEK2005)。

摘　　要：通过对沧州市石港铁路客运专线路基土进行冻融循环处理,采用控制变量法,分析冻融循环次数和冻结速率对土体抗剪强度的影响。结果表明:黏土的抗剪强度随冻融循环次数的增加而降低,前7次循环内变化较大,在1次循环后,土体发生应变软化现象,在3次循环后,抗剪强度开始降低,在7次循环后逐渐接近平衡强度,在20次循环后基本归于一个平均值;冻结速率对抗剪强度具有显著影响,较慢的冻结速率会导致较低的抗剪强度;在工程实际中,在施加载荷之前至少经历一个完整的冻融循环,以达到提高可靠性和安全性,减少维护成本的效果。Through the freeze-thaw cycle treatment of the subgrade soil of Shigang Railway Passenger Dedicated Line in Cangzhou,the influence of number of freeze-thaw cycles and the freezing rate on the shear strength of the soil mass was analyzed by using the control variable method.The result shows that,the shear strength of clay decreases with the increase of the number of freeze-thaw cycles,and changes greatly in the first seven cycles.After one cycle,the soil mass undergoes strain softening.After three cycles,the shear strength begins to decrease,and gradually approaches the equilibrium strength after seven cycles.At twenty cycles,it is basically attributed to an average value.The freezing rate bears a significant effect on the shear strength,and the slower freezing rate will lead to lower shear strength.In engineering practice,it is best to construct the basic components and experience at least a complete freeze-thaw cycle before applying the load,so as to improve the reliability and safety and reduce the maintenance cost.

关 键 词：黏土 冻融循环 固结 抗剪强度 冻融速率 稳定性 

分 类 号：TU43[建筑科学—岩土工程]