考虑降雨及裂隙影响的非饱和膨胀土边坡稳定性分析

项目名称： 考虑降雨及裂隙影响的非饱和膨胀土边坡稳定性分析

项目编号： No.41202246

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 李幻

作者单位： 华北水利水电大学

项目金额： 25万元

中文摘要： 非饱和膨胀土边坡土水状态对土体的力学、水力学特性起着至关重要的作用。前期降雨历史是影响非饱和土边坡稳定性的关键因素。裂隙的发育情况对膨胀土边坡的渗透性有着重要的影响。本研究旨在揭示降雨诱发滑坡问题的孕育演化机理的基础上，利用非饱和膨胀土的动态循环土水特征关系来描述毛细滞回效应,将动态循环土水特征关系与非饱和膨胀土强度公式结合，建立能反映任意干-湿循环历史影响下的非饱和土强度理论；在此基础上，建立能模拟、追踪在降雨入渗激励下非饱和土瞬态含水量、基质吸力、抗剪强度、塑性体积变化等参数动态变化过程的理论和数值模型，开发可以描述膨胀土裂隙产生发育的裂隙自生成程序，提出能够考虑前期降雨历史影响的非饱和土膨胀边坡稳定性分析方法，并开展室内试验对所建立的理论模型和分析方法进行验证。本研究希望为降雨诱发膨胀土边坡稳定性问题的预警预报和防治提供可靠的分析方法。

中文关键词： 膨胀土；干湿循环；裂隙；强度；变形

英文摘要： The water distribute condition of a unsaturated expansive soil slope has strong efects on the mechanic and hydraulic characteristic of the soil. The rainfall history is a key problem to the stability of an unsaturated expansive soil slope. The development state of the cracks have important effects on the permeability of the expansive soil slope. By coupling the hydraulic hysteresis model and the shear strength model, the appliant would develop a general constitutive model which is able to modify the hydraulic and mechanic character of unsaturated expansive soils. The changing processes of those parameters such as water content, matric suction, shear strength, plastic volume strain would be tracked. A program that can be used to describe the developmental process of the cracks would be developed. Then a analysis on stability of the unsaturated expansive slope that considering the effects of cracks and rainfall history would be developed. Laboratory soil test would be carried out to analyze and check the stability analysis that proposed by the applicant. This study is ready to propose a reliable anylysis method for the unsaturated expansive soil slope unstability that caused by rainfall.

英文关键词： Expansive soil；Wet and dry cycle；Cracks；Strength；deformation