控制体变及干湿循环下膨胀土强度变化规律研究  

Strength variation of expansive soil under lateral restraint and wet-dry cycling

作　　者：刘专[1] 王志俭[1] 曹玲[1] 叶建华[1] 

机构地区：[1]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《人民长江》2012年第24期60-63,共4页Yangtze River

基　　金：国家自然科学基金资助项目(41172298)

摘　　要：在控制体变条件下,用三轴仪对经历干湿循环后的膨胀土抗剪强度进行测定,分析得到抗剪强度随干湿循环次数的变化规律。结果表明:膨胀土的凝聚力随干湿循环次数的增加而降低,最初3次衰减幅度最大,随后趋于稳定,其变化趋势可用指数衰减函数描述;膨胀土的内摩擦角受干湿循环影响不大。建议在设计膨胀土边坡时,选用干湿循环后稳定的强度参数值作为设计参数。Restraining the volume strain of expansive soil,we use tri-axial apparatus to conduct shear strength tests for expansive soil that has passed through the cycling of wetting and drying,obtaining the shear strength variation law under different cycling times.The test results show that the cohesion of expansive soils samples decreases with the increment of dry-wet cycling times and the declining amplitude in the first three cycles is the largest and then tends to be stable,and the declining law can be fitted by exponential attenuation function;the internal friction angle of expansive soil samples is influenced slightly by the wet-dry cycling.It is suggested that the stable strength parameters after wet-dry cycling should be adopted as design parameters.

关 键 词：膨胀土 体变 干湿循环 抗剪强度 

分 类 号：TU443[建筑科学—岩土工程]