循环荷载作用下广州软土长期累积变形特性试验研究  

Experimental Study on Long-term Cumulative Deformation of Guangzhou Soft Clay under Cyclic Loads

作　　者：王强 WANG Qiang(China Railway 11th Bureau Group Co.,Ltd.,Wuhan 430061,China)

机构地区：[1]中铁十一局集团有限公司,湖北武汉430061

出　　处：《安全与环境工程》2022年第4期205-210,219,共7页Safety and Environmental Engineering

基　　金：校企联合科技攻关项目(2019056083)。

摘　　要：软土长期累积变形特性对软土地区地铁和高铁等地基沉降变形控制至关重要。以广州地铁隧道附近的淤泥质黏土和粉质黏土为研究对象,通过室内GDS循环三轴仪,在考虑土体性质和荷载频率两种影响因素下对广州软土进行循环动三轴试验,研究了循环荷载作用下广州软土的长期累积塑性变形特性和规律。结果表明:同一荷载频率下广州地区淤泥质黏土的长期累积塑性变形量约为淤泥质粉质黏土的1.6倍;基于试验数据和已有研究成果,广州软土地区淤泥质黏土和淤泥质粉质黏土的临界循环应力值不超过30 kPa;此外,分析了现有常用的土体累积塑性应变计算模型的优缺点和适用范围,推荐给出了适合广州地铁行车荷载作用下软土地基长期变形控制与计算的模型。该研究成果可为广州软土地区地铁隧道变形控制与计算提供依据。Long-term cumulative deformation of soft soil is crucial to the settlement deformation of subway and high-speed railway foundations in soft soil areas.By considering soil type and loading frequency,this paper carries out a series of cyclic triaxial tests to explore the cumulative plastic deformation of soft soil originated from silty clay and mucky clay near Guangzhou metro tunnels.The test results show that the cumulative plastic deformation of the mucky clay is about 1.6 times of that of the silty clay under the same loading frequency.Based on the test data and existing research results,the critical cyclic stress both for Guangzhou soft muddy clay and silty clay should not exceed 30 kPa.In addition,the advantages and drawbacks of commonly used models of cumulative plastic strain are analyzed,and suitable models for the deformation calculation of soft soil foundation under the subway traffic load are recommended.The results can provide theoretical basis for the deformation calculation of metro tunnels in soft soil areas in Guangzhou.

关 键 词：软黏土 循环荷载 动三轴试验 荷载频率 累积塑性变形 

分 类 号：X951[环境科学与工程—安全科学] TU41[建筑科学—岩土工程]