甘肃黑方台突发型黄土滑坡形成过程的物理模拟

中国黑方台地区发育了大量突发型黄土滑坡,这类滑坡变形破坏过程中伴随了显著的超孔隙水压力,通过现场调查概化这类滑坡的特征建立模型进行室内物理模拟,还原了这类滑坡的变形破坏过程,并分析了孔隙水压力与位移的响应规律,结果表明:滑坡变形前地下水产生的孔隙水压力需要达到一定程度,坡体破坏前出现了持续性的缓慢蠕动,在此期间滑坡体后方的孔隙水压力产生波动导致变形加快,进一步促使滑坡体内部产生超孔隙水压力,最终使土体产生显著的超孔隙水压力导致滑坡失稳破坏。黑方台地下水产生的静孔隙水压力是使突发型滑坡产生蠕动变形的原因,而蠕动变形导致的孔隙水压力波动是造成滑坡变形突增失稳破坏的诱因。

Physical simulation study on the forming process of sudden loess landslide in Heifangtai, Gansu province

A large number of sudden loess landslides have been developed in Heifangtai area of China. The process of deformation and failure of these landslides is accompanied by significant excess pore water pressure. Through field investigation, the characteristics of these landslides are generalized and the model is established for indoor physical simulation. The process of deformation and failure of these landslides is restored, and pore water pressure and displacement are analyzed. The results show that the pore water pressure produced by groundwater before landslide deformation needs to reach a certain degree, and there is a sustained slow creep before slope failure. During this period, the pore water pressure behind landslide body fluctuates and causes accelerated deformation, which further promotes excess pore water pressure in the inner part of landslide. Finally, the obvious excess pore water pressure of the soil leads to the instability and failure of the landslide. The static pore water pressure produced by groundwater in Heifangtai is the cause of creep deformation of sudden landslide, and the fluctuation of pore water pressure caused by creep deformation is the inducement of the sudden increase of landslide deformation and instability damage.