含水率梯度作用下填埋场压实黏土层开裂特性试验与机理分析  

EXPERIMENTS ON CRACKING CHARACTERISTICS AND MECHANISM ANALYSIS OF COMPACTED CLAY LAYERS IN LANDFILLS UNDER THE ACTION OF WATER CONTENT GRADIENT

作　　者：刘瑞琪 雷学文[1] 万勇[2] 刘磊 LIU Ruiqi;LEI Xuewen;WAN Yong;LIU Lei(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China)

机构地区：[1]武汉科技大学城市建设学院,武汉430065 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071

出　　处：《力学与实践》2022年第1期12-21,共10页Mechanics in Engineering

基　　金：国家自然科学基金资助项目(51979267,41772342)。

摘　　要：为探究压实黏土防渗层干缩开裂的力学机制,开展了压实黏土层含水率梯度变化与干缩裂隙演化规律试验研究,并构建了含水率梯度作用下压实黏土层开裂分析模型,研究结果表明:蒸发过程中,压实黏土层失水率随深度指数递减,高液限黏土含水率梯度明显高于低液限黏土。压实黏土层表层拉应力随含水率梯度的增加而增加。蒸发过程中,低液限压实黏土层含水率梯度小,表层拉应力低,裂隙较少;而高液限黏土试验和理论分析结果与之相反。In order to investigate the mechanical mechanism of dry shrinkage cracking in compacted clay impermeable layer,the experimental study of water content gradient change and dry shrinkage crack evolution law of compacted clay layer was carried out.Meanwhile,the analytical model of compacted clay layer cracking under the action of water content gradient was constructed.The research results showed that the water loss rate of compacted clay layer decreases with depth index during evaporation,and the water content gradient of high liquid limit clay is significantly higher than that of low liquid limit clay.The tensile stress in the surface layer of compacted clay layer increases with the increase of water content gradient.During evaporation,the water content gradient of low liquid-limit compacted clay layer is small,the surface tensile stress is low,and there are fewer fissures;while the results of experimental and theoretical analysis of high-liquid-limit clay are opposite.

关 键 词：压实黏土 含水率梯度 干缩开裂 应力分布函数 解析解 

分 类 号：TU442[建筑科学—岩土工程]