水力梯度作用下填埋场压实黏土盖层开裂失效机理研究

项目名称： 水力梯度作用下填埋场压实黏土盖层开裂失效机理研究

项目编号： No.51509245

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 水利工程

项目作者： 万勇

作者单位： 中国科学院武汉岩土力学研究所

项目金额： 20万元

中文摘要： 填埋场压实黏土盖层开裂失效是致使填埋场灾变与周边环境污染的主要原因之一。压实黏土开裂失效归因于黏土失水收缩这一内在本质，其外在诱因为盖层内部含水率梯度分布致使黏土非均匀变形。探究水力梯度对压实黏土层开裂的影响对揭示压实黏土干缩开裂机理具有重要意义。本项目拟应用非饱和土力学、渗流力学、断裂力学、以及环境岩土工程等多学科交叉的理论和方法，通过开展水力梯度作用下填埋场压实黏土盖层相似模型体试验、力学-渗透特性单元体试验以及微观结构特性试验研究，从宏-微观多个尺度揭示水力梯度作用下压实黏土盖层的力学特性、渗透机理以及开裂机制，建立水力梯度作用下填埋场压实黏土盖层开裂动力演化模型，定量分析在水力梯度作用下压实黏土盖层裂隙发生、发展和演化的动力学规律，从机理上深入揭示影响黏土盖层开裂过程的主控因素和内在机制，为填埋场粘土盖层开裂失效防治和新型覆盖系统的优化设计提供理论指导与技术支持。

中文关键词： 覆盖层；压实黏土层；水力梯度；开裂；失效机理

英文摘要： The cracking failure of compacted clay cover is one of the main causes which make landfill catastrophe and the surroundings polluted. With the gradient distribution of water content in cover as external drive leading to the inhomogeneous deformation in clay, the shrinkage in clay due to water loss is the internal essence of cracking failure. In order to show the clay crack mechanism, it is of great significance to research the influence of hydraulic gradient on the crack in clay cover. Aiming at showing the main factor and internal mechanism in the formation process of clay cover crack deeply and providing theoretical guidance and technical support for the optimal design of new cover system and crack prevention of landfill clay cover, the project intends to use multi-disciplinary theory and method including unsaturated soil mechanics, seepage mechanics, fracture mechanics, environmental geotechnical engineering, etc . Through landfill-compacted-clay-cover model experiment under hydraulic gradient, mechanics-seepage element experiment and microstructure experiment, the project reveals the mechanics character, permeation mechanism and crack mechanism of compacted clay cover under hydraulic gradient on macro- micro multiple scales, establishes crack drive evolution model of landfill compacted clay cover under hydraulic gradient and quantitatively analyses the dynamic law of crack formation, development and evolution in compacted clay cover.

英文关键词： landfill final cover;Compacted clay line;Hydraulic gradient;Crack;Failure mechanism