干-湿分明条件下降雨诱发滑坡演化过程模拟

Simulation Analysis on the Evolution Process of Rainfall-induced Landslide Under Dry-wet Conditions

降雨诱发的堆积体边坡地质灾害在我国南方地区极为常见,揭示其失稳演化规律对我国山地丘陵地区的土质滑坡监测预警具有重要意义。基于鄂西地区降雨型滑坡的典型地质概化模型与降雨模型研究,联合采用Geo-Studio软件的Seep/W、Sigma/W模块,从渗流场、应力场及位移场等方面对降雨诱发滑坡的响应过程进行研究,探讨了干湿分明情况下堆积体边坡失稳的演化过程。与未经历长期干旱的边坡相比,经历长期干旱作用可以使得降雨向坡体更深处入渗,基质吸力变化范围更大,降雨引起的坡内土体位移更大。且经历干旱条件时,可明显看到沿着坡脚向上贯通且面积较大的塑性区分布,边坡最终更有可能发生失稳破坏。研究成果在推动鄂西地区边坡滑坡地质灾害的防治理论发展方面具有积极作用。

The geological hazards of rainfall-induced accumulation slope are very common in south of China.It is of great theoretical and practical significance to reveal the law of instability evolution for the monitoring and early warning of soil landslide in mountainous and hilly areas of China.Based on the generalized model of typical geological landslides and rainfall model of rainfall induced landslide in western Hubei area,combined the Geo-Studio software,the evolution process of the slope destabilizing were discussed from the aspects of seepage field,stress field and displacement field of wet and dry conditions.Compared with the slope that has not experienced long-term drought,the long-term drought can make rainfall infiltrate deeper into the slope,the variation range of matrix suction is larger,and the soil displacement in the slope caused by rainfall is larger at the same time.Under drought conditions,it is obvious that the plastic zone with large area is distributed along the slope foot,and the slope is more likely to fail and fail eventually.The research results play a positive role in promoting the theoretical development of the prevention and control of landslide geological hazards in western Hubei province.