降雨致滑的土坡体积演化规律研究

前人对滑坡演化划分为蠕动压密、滑动、剧滑和稳定压密四阶段.对于新开挖的土质边坡,若在降雨作用下发展为滑坡,在滑坡演化的蠕动压密阶段存在明显的体积减小,滑坡演化的滑动阶段体积变化不明显.因此,若土坡在降雨作用下持续变形,可将边坡体积变化作为边坡由蠕动压密阶段转化为滑动阶段的判据,据此对边坡危险性进行预警.采用室内地质力学模型模拟了土坡在降雨作用下的失稳过程,坡面位移持续增大,坡体体积先持续减小后渐趋稳定,坡体出现整体失稳,验证了坡体体积减小的终点就是滑坡滑动阶段的起点.

Study on Evolution Law of Slope Volume Caused by Rainfall

The evolution of landslide was divided into four stages,namely,creeping compaction,sliding,severe sliding and stable compaction,according to the previous studies.For a soil slope excavated lately,it,when developing into landslide under the action of rainfall,has significant reduced volume in the stage of creeping compaction,and then unapparent volume change in the stage of sliding.Therefore,if under the action of rainfall the soil slope deforms continuously,the change of slope volume may be taken as the criterion for a slope developing from the stage of creeping compaction into the stage of sliding,depending on which early warning may be made against the hazard of slope.Then laboratory geomechanics model was used to simulate the process of soil slope failure caused by rainfall that the slope surface displacement keeps increasing and the slope volume keeps decreasing first then tends to be stable gradually,then the slope appear to be instable as a whole,which verified the endpoint of slope volume decrease is the startpoint of sliding stage of landslide.