饱和重塑黄土在部分排水条件下的力学特性研究  

Mechanical properties of saturated remolded loess under partial drainage conditions

作　　者：张林 陈存礼 张登飞 庞腾腾 游子龙 孙佩娜 ZHANG Lin;CHEN Cunli;ZHANG Dengfei;PANG Tengteng;YOU Zilong;SUN Peina(Shaanxi Provincial Key Laboratory of Loess Mechanics and Engineering,Institute of Geotechnical Engineering,Xi'an University of Technology,Xi'an 710048;State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi'an 710069;Shanghai Zhongjian Dongfu Investment and Development Co.,LTD.,Shanghai 200120)

机构地区：[1]西安理工大学岩土工程研究所陕西省黄土力学与工程重点实验室 [2]西北大学地质学系大陆动力学国家重点实验室 [3]上海中建东孚投资发展有限公司

出　　处：《水力发电学报》2019年第12期112-120,共9页Journal of Hydroelectric Engineering

基　　金：中国博士后科学基金项目(2018M633559);国家重点研发计划项目(2018YFC1504703)

摘　　要：针对黄土地区实际加载工程中部分排水问题,利用多功能GDS应力路径三轴仪开展饱和黄土不同排水条件下的三轴试验,研究了不同排水条件下饱和重塑黄土的强度特性。试验结果表明:饱和重塑黄土的强度随应变增量比的增大而增大,剪切过程中产生的超孔隙水压力随应变增量比的增大而减小;不同排水条件对土的强度特性的影响在两个方面:一是荷载条件,即土的有效应力路径,使得排水和吸水条件的加载模式不同;二是土性条件,即体积变形约束制约着土样剪胀特性的发挥,进而影响内摩擦角的发挥程度,形成渐近状态。根据试验数据,分析了不同排水条件下应力路径及渐进状态变化规律,调整了极限应力比的计算方法,得出饱和重塑黄土的极限应力比与应变增量比的线性关系方程。Aiming at the investigation of partial soil drainage under loading conditions of engineering projects in loess areas,we conduct triaxial tests of saturated loess samples using a muti-functional GDS stress path triaxial apparatus,and examine the strength of saturated remolded loess under different drainage conditions.Results show that as the strain increment ratio increases,the strength increases while the excess pore water pressure generated through shearing decreases.The influence of partial drainage on soil strength is in two aspects:one is that the load condition,or the effective stress path of soil,makes the loading mode of drainage different from that of water absorption;the other is the soil property,i.e.,the volume deformation characteristics influence the development of shear dilatation and thereby affects the internal friction angle of soil so that finally the soil develops into an asymptotic state.Based on the present experimental data,we analyze the variation trends in stress path and asymptotic state under different drainage conditions,adjust the calculation method of limit stress ratios,and obtain a linear relationship equation of limit stress ratio versus strain increment ratio of saturated remolded loess.

关 键 词：饱和黄土 部分排水 强度特性 渐近状态 

分 类 号：TU411[建筑科学—岩土工程]