摘要
降雨入渗是诱发土石混合体边坡失稳的主要因素之一,此类问题一直受到人们的关注,但对此问题的研究不够系统和深入。为了对降雨入渗诱发下土石混合体滑坡的失稳机理有较深的了解及研究边坡性状随时间变化的一些重要特性,在上瑞高速公路贵州段选取了一个典型的土石混合体边坡进行人工降雨模拟试验和原位综合监测。监测成果表明:降雨入渗影响下土石混合体边坡的滑动变形区为坡面以下0～4 m之间,变形量以坡面最大,从坡面到坡体深部逐渐减小;在实施降雨的前2 h,平均入渗百分率为86%,之后,入渗率由于地表径流的增加而随时间逐渐减少,一段时间(6 h)之后,入渗率降到一个相对稳定值(50%);降雨入渗造成土体中孔隙水压力增加,致使边坡土体的抗剪强度由于有效应力的减少及土体吸水软化而降低,降雨入渗的这一双重效应可能是降雨诱发土石混合体边坡失稳的主要原因之一。
Rainfall and its infiltration into a soil-rock-mixture slope is one of the most important factors affecting slope stability. The problem of soil-rock-mixture slope instability caused by rainfall has been paid close attention by people all the time, but the study on this problem not enough systemic and thorough. In order to improve our understanding of the fundamental mechanism of rainfall infiltration induced landslides in soil-rock-mixture landslide and to clarify some of important characteristic of slope performance, artificial rainfall simulation tests and field synthetic monitored method were carried out on a typical soil-rock-mixture slope in Guizhou province near Shangrui Freeway. The monitored results demonstrate that the deformed zone of soil-rock-mixture landslides caused by rainfall infiltration lies within the top 0-4 m soil layer, where the deformation value of slope surface is the biggest, which gradually reducing from dome to the deep part of slope. The average percentage of infiltration during the first 2 hours is 86 %, it reduces gradually with time later because of the increase of the surface runoff. The average percentage of infiltration drop to a relatively stable value （50 %） 6 hours later. Rainfall infiltration leads pore-water pressure to increase, which may result in a reduction of shear strength due to a decrease in effective stress and wetting-induced softening. The double effects of rainfall infiltration are the main reasons of rainfall infiltration induced landslides in soil-rock-mixture slope.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2007年第7期1391-1396,共6页
Rock and Soil Mechanics
基金
西部交通建设科技项目"西部地区公路地质灾害监测预报技术研究(No.2003-318-802-01)"
关键词
边坡
土石混合体
人工降雨模拟试验
降雨入渗
现场监测
slope, soil-rock-mixture, artificial rainfall simulation tests, rainfall infiltration, in-situ monitoring
作者简介
周中，男，1978年生，博士生，主要从事边坡工程及地下工程方面的研究工作。E-mail：dazhong78@126．com。
