基于不连续布局优化法的那勒寺古滑坡稳定性分析

Stability Analysis of the Nalesi Ancient Landslide Based on the Discontinuous Layout Optimization

巴谢河(那勒寺河)流域地处陇西黄土高原西部临夏构造盆地中心,河北岸新老滑坡十分发育,那勒寺古滑坡就是其中最具代表性的一个,且因切坡建房,坡脚形成高20 m的临空面,存在一定危险性。笔者在野外调查滑坡发育特征的基础上,采用不连续布局优化法(Discontinuity Layout Optimization,DLO),分析了在天然状态、极端降雨以及地震工况条件下的滑坡稳定性。结果表明:在天然工况下其稳定系数为1.49,在极端暴雨及地震工况下的稳定性系数分别为0.95,0.96,可见其当前稳定,但在不利条件下存在失稳的可能。建议在滑坡体治理工程设计时采取前缘支挡、后缘及坡面疏通排水等综合防治措施,并尽快开展专业监测,切实保护坡脚和那勒寺镇居民的生命和财产安全。

The Baxiehe basin is located in the center of the Linxia tectonic basin in the western part of the Loess Plateau in Gansu Province.On the northern bank of the river,the ancient and new landslides are well developed,one of which is the Nalesi ancient landslide.The slope of the Nalesi landslide was cut to build houses and thus formed a 20 m high surface,which is dangerous.On the basis of field investigation,this paper analyzes the stability of the landslides under natural conditions,extreme rainfall,and seismic conditions,using Discontinuous Layout Optimization(DLO).The stability coefficient is 1.49 under natural condition,0.95 under extreme torrential rain,and 0.96 under seismic condition.The results show that there is a possibility of instability under adverse conditions.It is suggested that in the design of landslide treatment,comprehensive prevention such as front edge retaining,back edge and slope dredging and drainage should be taken,and professional monitoring should be carried out as soon as possible to protect both the life and property of the residents at the foot of slope and in the Nalesi town as well.