干湿循环条件下陕南膨胀土力学特性研究  

Study on Mechanical Properties of Expansive Soil in Southern Shaanxi under Wetting-Drying Cycles

作　　者：支枭雄 李宝平[1] 张玉[1,2] 王哲成 王鹏[1] ZHI Xiaoxiong;LI Baoping;ZHANG Yu;WANG Zhecheng;WANG Peng(School of Civil&Architecture Engineering,Xi’an Technological University,Xi’an 710021,China;Shaanxi Key Laboratory of Loess Mechanics and Engineering,Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]西安工业大学建筑工程学院,西安710021 [2]西安理工大学陕西省黄土力学与工程重点实验室,西安710048

出　　处：《西安工业大学学报》2021年第2期174-180,共7页Journal of Xi’an Technological University

基　　金：国家自然科学基金(11802218);陕西省科技计划项目(2019JQ 432;2019JQ 835)。

摘　　要：为保证陕南膨胀土地区工程施工安全,以陕南膨胀土为研究对象,通过常规三轴试验,分析初始含水率和干湿循环次数两个因素对陕南膨胀土应力应变关系和抗剪强度特性的影响。结果表明:初始含水率和干湿循环次数均与膨胀土峰值强度呈负相关;第一次干湿循环对膨胀土峰值强度和抗剪强度的降低幅度远大于后续干湿循环;膨胀土在多次干湿循环作用下,黏聚力大幅降低造成抗剪强度衰减;黏聚力和内摩擦角随着初始含水率的增大而减小,且基本呈线性关系。In order to ensure the safety of engineering construction in the expansive soil area of southern Shaanxi,Taking the expansive soil in southern Shaanxi as the research object,through conventional triaxial tests,the influences of initial moisture content and number of wetting and drying cycles on the stress-strain relationship and shear strength characteristics of expansive soil in southern Shaanxi were analyzed and studied.The result shows:The initial moisture content and the number of wetting and drying cycles are negatively correlated with the peak strength of expansive soil;The decrease of peak strength and shear strength of expansive soil in the first dry wetting cycle is much greater than that in the subsequent cycles;Under the action of multiple dry and wet cycles,the cohesive force of the parameters of the expansive soil is greatly reduced,resulting in attenuation of shear strength;The relationship between cohesion and internal friction angle is linear with increasing initial water content.

关 键 词：干湿循环 膨胀土 抗剪强度 三轴试验 

分 类 号：TU443[建筑科学—岩土工程]