渗流作用下孔隙水压力对坡面固体物质起动的机理研究

项目名称： 渗流作用下孔隙水压力对坡面固体物质起动的机理研究

项目编号： No.41502330

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 地质学

项目作者： 杨顺

作者单位： 中国地质科学院探矿工艺研究所

项目金额： 21万元

中文摘要： 渗流作用下泥石流源区固体物质失稳、起动形成泥石流是山区最为常见的灾害之一，尤其汶川地震后，坡面泥石流常常直接威胁灾区人民生命财产安全和生态环境。目前，降雨条件下坡面固体物质失稳、起动形成泥石流等机理研究较多，而渗流作用下坡面固体物质起动机理较少。因此，在选择坡体模型的基础上，首先从泥石流动力学入手，通过力学分析，建立饱和渗流作用下坡面固体物质起动的动力表达式、抗水动力表达式，根据力学平衡原理，建立固体物质起动的临界厚度判别式；其次，通过物理模型试验对动力和临界厚度表达式进行验证及修正，分析孔隙水压力在坡面固体物质起动过程中的作用机制；最后，开展泥石流源区坡面土体在饱和/非饱和渗流条件下孔隙水压力、含水量等原位试验、观测，分析孔隙水压力、含水量在泥石流起动过程中的变化特征，验证坡面固体物质起动的临界厚度，探讨泥石流源区固体物质在渗流条件下的起动机理问题，对指导泥石流灾害防治具有重要意义。

中文关键词： 渗流作用；孔隙水压力；固体物质；起动；作用机理

英文摘要： The loosen solid materials fail to form debris flow under seepage effect is one of the most common disasters in mountainours areas, especially post Wenchuan Earthquake, the high frequency of slope-debris flow affected the safety of human life and properties, as well as ecological environment. Presently, more researches of mechanics theory and experiments are focused on the solid materials failure, initiation condition and movement process, but less attentions are paid on the pore water pressures variation of loosen solid materials under seepage flow. Thus, based on the chosen slope model, the project analyze the mechanism problem of pore water pressures, through debris flow dynamics firstly, take mechanics analysis with infinite simal body to set up dynamic fomula, resistance fomula and critical thickness formula under saturated seepage flow effect; further more, to test and verify the theory results right or not, the project carry out the model experiment on condition of different discharge and slope gradient, and analyze the mechanism of pore water pressure during solid materials initiation process; last, take field experiment and observation, to analyze the characteristics of water content, pore water pressure in saturated/ unsaturated seepage condition in debris flow source area, as well to testify the critical initail thickness and probe the initiation mechanics problems of debris flow under seepage flow, which have a significant meaning on guiding the debris flow prevention and mitigation in advance.

英文关键词： Seepage Flow;Pore Water Pressure;Solid Materials;Initiation;Mechanism