前期含水率对浅层滑坡降雨入渗及稳定性影响研究

发布时间：2019-02-26 17:56

【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。
[Abstract]:Rainfall is one of the main factors inducing landslide. At present, it is generally believed that the decrease of soil matrix suction caused by the downward movement of wetting front is the main cause of the landslide instability, and the soil moisture content is one of the important factors affecting the process of wet front moving down. Based on the Green-Ampt model, the expression of rainfall infiltration under the influence of slope angle is derived. At the same time, the variation of the stability of the landslide under the condition of continuous and stable rainfall is analyzed in combination with the infinite slope model. The influence of water content on the stability of shallow landslides during rainfall is discussed. The results show that with the continuous rainfall, the stability of shallow landslides begins to decline rapidly, and then tends to smooth. When the moisture content in the early stage is 0.32, 0.36, 0.40 respectively, the wet front moves down 0.109, 0.173, 0.42 mhm / h respectively, indicating that the higher the moisture content in the early stage, the faster the wet front moves downwards, and when the moisture content is 0.32, 0.36, 0.40 respectively, the wet front moves down more quickly when the early moisture content is 0.32, 0.36 and 0.40 respectively. However, the effect of water content on the stability of shallow landslides is mainly in the early stage of rainfall.
【作者单位】：中国地质大学(武汉)地质调查研究院;中国地质大学(武汉)工程学院;
【基金】：国家自然科学基金项目(41572292;41572289)
【分类号】：P642.22

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