摘要
降雨是诱发滑坡的主要因素之一。目前普遍认为,湿润锋下移导致的土体基质吸力减少是降雨影响滑坡失稳的主要原因,而土壤前期含水率是影响湿润锋下移过程的重要因素之一。基于Green-Ampt模型,推导了考虑坡角影响下的滑坡体降雨入渗表达式,同时,结合无限斜坡模型分析了持续稳定的降雨条件下滑坡体稳定性的变化情况,探讨了前期含水率对于降雨过程中浅层滑坡稳定性的影响规律。结果表明:随着降雨的持续进行,浅层滑坡稳定性开始下降较快,之后趋于平缓。前期含水率会影响湿润锋的下移速度,当前期含水率分别为0.32,0.36,0.40时,湿润锋下移速度分别为0.109,0.173,0.42m/h,说明前期含水率越大,湿润锋下移的速度越快;而前期含水率对于浅层滑坡稳定性的影响主要在降雨初期。
The rainfall is one of the important factors for inducing the landslide. Nowadays, many researches show that the drawdown of the wetting front can lead to reduce the matric suction. It is the main reason for the landslide instability. In addition, the initial water content is one of significant reasons that affects the drawdown of the wetting front. In this article, the formula is deduced with the consideration of the slope angle of the landslide under the influence of the rainfall infiltration rule based on the Green-Ampt model. In addition, the stability of the landslide is analyzed by using infinite slope model under the condition of steady and small rainfall. Finally, the article discusses the effect of initial water content on the stability of the shallow landslide in the condition of rainfall.. The result shows that the stability of Madiwan landslide is declined quickly in the start time, and then it becomes flat. The drawdown speed of wetting front can be affected by the initial water content. When the initial water content are 0.32, 0.36 and 0.4 respectively, the drawdown speed of wetting front are 0. 109 m/h, 0. 173 m/h and 0.42 m/h respectively. The result suggeststhat the bigger the initial water content is, the faster the drawdown speed of wetting front is. But the initial water content for the effect on the stability of the shallow landslide is mainly at the beginning of the rainfall.
出处
《地质科技情报》
CSCD
北大核心
2017年第5期204-208,237,共6页
Geological Science and Technology Information
基金
国家自然科学基金项目(41572292
41572289)
