科技通报

为研究湟水流域典型滑坡的变形特征与稳定性。以湟水流域王家庄滑坡为调查对象，通过现场调查、数值模拟、结合室内综合分析查明该滑坡的变形特征及成因机制，采用双折减系数法分析了滑坡在天然及暴雨工况下的位移场、应力应变场及综合安全系数，并与单强度折减法、极限平衡法结果进行对比，研究了顺层滑坡的稳定性。结果表明：该顺层滑坡前缘处因降雨及人工切坡作用导致坡脚失稳，产生沿坡面向下的牵引力，降雨侵蚀作用导致滑坡后缘处土体抗剪强度逐渐下降，下滑力增大，推动滑坡中部土体沿坡面向下移动，滑坡最终发生失稳破坏，破坏模式为“推移-牵引”式滑坡；天然工况下，单折减时安全系数为1.59，双折减时滑坡安全系数为1.44，均处于稳定状态；在强降雨作用下，滑坡位移场持续增大，剪切应变特征逐渐明显，有效应力呈先增大后减小趋势，安全系数不断下降，单折减时安全系数为1.13，处于基本稳定状态，双折减时滑坡安全系数为1.05，滑坡处于欠稳定状态，容易发生失稳风险。相较于单强度折减法，采用双折减系数法得到的安全系数更为精确合理。双折减系数法能够提高在不同工况下滑坡稳定性分析的准确性，研究成果可为双折减系数法在顺层滑坡稳定性分析中的应用提供参考。

In order to study the deformation characteristics and stability of typical landslides in Huangshui River Basin.Taking the Wangjiazhuang landslide in Huangshui River Basin as the investigation object, the deformation characteristics and formation mechanism of the landslide are identified by field investigation,numerical simulation and indoor comprehensive analysis. The displacement field, stress-strain field and comprehensive safety factor of the landslide under natural and rainstorm conditions are analyzed by double reduction coefficient method. The results are compared with those of single strength reduction method and limit equilibrium method to study the stability of bedding landslide. The results show that the leading edge of the bedding landslide is unstable at the foot of the slope due to rainfall and artificial slope cutting,resulting in a downward traction force along the slope. Rainfall erosion leads to a gradual decrease in the shear strength of the soil at the trailing edge of the landslide,and the sliding force increases,which promotes the soil in the middle of the landslide to move down along the slope,and the landslide finally fails. The failure mode is ' push-pull ' landslide; under natural conditions,the safety factor of single reduction is 1.59,and the safety factor of double reduction is 1.44,both of which are in a stable state. Under the action of heavy rainfall,the displacement field of the landslide continues to increase,the shear strain characteristics gradually become obvious,the effective stress increases first and then decreases,and the safety factor continues to decline. The safety factor is 1.13 when the single reduction is in the basic stable state,and the safety factor is 1.05 when the double reduction is in the basic stable state. The landslide is in an unstable state and prone to instability and failure. Compared with the single strength reduction method, the safety factor obtained using the double reduction coefficient method is more accurate and reasonable. The double reduction coefficient method can improve the accuracy of landslide stability analysis under different working conditions. The research results can provide reference for the application of double reduction coefficient method in the stability analysis of bedding landslide.