Rainfall-induced tuff slope containing weak interlayers are the main type of landslides in the south of Zhejiang Province. In order to further understand the impact of different weakening modes of weak interlayers on landslide stability. This study uses the strength reduction method in Midas GTX NX software to analyze the deformation characteristics ofthe typical tuff landslide Chengtian landslide in Songyang county under different rainfall conditions. At the same time,the S-shaped curve weakening model of weak interlayer strength is introduced,and the coupling model considering fracture water pressure and seepage force is optimized. The evolution characteristics of stability coefficient of landslide are compared and disscussed. The results show that the deformation signs of the landslide and the numerical simulation results are mutually confirmed. The deformation zone expands and evolves from the rear edge to the front edgeof weak interlayers during continuous rainfall. The strength weakening of weak interlayers with high clay minerals caused by heavy rainfall is the primary factor leading to the instability of landslide. The stability factors of thelandslideare calculated by the S-shaped curve weakening model of the weak layerwill decrease with the increase of water head in tension cracks and phase characterization values λL,which reflect the time effect of deformation of landslide. The S-shaped curve weakening model of weak interlayer is more suitable for landslide risk assessment. The landslide stability coefficient calculated by the limit equilibrium method highlights the uniqueness of the calculation results,which is suitable for the risk decision-making of landslide rescue on the premise of safety.
关键词
凝灰岩边坡/数值模拟/致灾机制/夹层强度"S"型曲线弱化模型/稳定性分析
Key words
tuff slope/numerical simulation/disaster-causing mechanism/S-shaped curveweakening model of weak layer/stability analysis
万方数据