压实黄土地基载荷浸水模型试验及湿陷变形计算方法研究  

Loading-wetting model test on the compacted loess foundation and calculation of its collapsible deformation

作　　者：孙磊 胡海军[1] 严瑞珉 党进谦[1] 张爱军[1] 骆亚生[1] SUN Lei;HU Haijun;YAN Ruimin;DANG Jinqian;ZHANG Aijun;LUO Yasheng(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《地震工程学报》2023年第2期319-328,共10页China Earthquake Engineering Journal

基　　金：国家自然科学基金青年科学基金资助项目(51409220);西北农林科技大学基本科研业务费专项资金项目(2014YB049);陕西省自然科学基础研究计划项目(2021JM-107)。

摘　　要：为研究压实黄土地基湿陷变形规律和已有湿陷变形计算方法的可靠性,开展室内杨凌压实黄土地基载荷浸水模型试验,应用一维湿陷系数法、弦线模量法和切线模量法三种方法计算其湿陷变形量,并与实测结果进行对比。实验结果表明压实黄土地基浸水后,湿陷变形很快发生,随后湿陷变形量随时间几乎不再增加,湿陷变形集中在附加应力作用的地基上部土层。三种方法计算的湿陷变形结果表明:荷载板受荷较小时,不考虑侧向挤出和考虑侧向挤出修正系数的一维湿陷系数法所得湿陷变形量分别接近和大于实际变形量;受荷较大时,不考虑侧向挤出和考虑侧向挤出修正系数的一维湿陷系数法所得湿陷变形量均远小于实际变形量。基于原位载荷试验获得的弦线模量不适用于重塑压实黄土地基湿陷变形量计算。切线模量法由于未能较好考虑初始屈服面的弹性变形,计算所得湿陷变形量大于实际变形量。To study the collapsible deformation development of the compacted loess foundation and the reliability of existing calculation methods for collapsible deformation,the indoor loading-wetting model test was carried out on the compacted loess foundation in Yangling.The collapsible deformation was calculated using the one-dimensional collapsibility coefficient method,chord modulus method,and tangent modulus method.The calculated results were then compared with the measured results.The experimental results show that collapse deformation occurs quickly after the foundation is wetted and then reaches stability.Due to non-self-weight collapse,collapse deformation occurs mainly in the top layer of the loess foundation.Calculated results of the three methods show that under a small load,the collapse deformations calculated by the one-dimensional collapsibility coefficient method without considering lateral extrusion are close to the measured values,while the deformations calculated while considering the modification factor of lateral extrusion are greater than the measured values.Under a large load,the collapse deformations calculated by the one-dimensional collapsibility coefficient method with and without considering the lateral extrusion are far less than the measured values.The chord modulus obtained from the in-situ loading test is unsuitable for calculating the collapse deformation of the compacted loess foundation.Since the elastic deformation of the initial yield surface is not well considered,the collapse deformation calculated by the tangent modulus method is greater than the measured value.

关 键 词：压实黄土地基 载荷浸水试验 增湿变形 弦线模量 切线模量 

分 类 号：TU444[建筑科学—岩土工程]