改进的不平衡推力法在滑坡地震动力稳定性分析中的应用

不平衡推力法是目前规范推荐的地震作用下滑坡地质灾害的稳定性评价的主要研究手段之一.传统的不平衡推力法处理地震荷载采用单值输入,不考虑地震波在岩土体中传播过程中的时空变化.针对该问题,基于滑坡体地震波传播规律,改进形成了考虑多点地震作用的不平衡推力法.针对云南某高速公路沿线典型滑坡,开展不同地震烈度下的不平衡推力与安全系数分析,研究结果表明:考虑多点地震作用的滑坡稳定性较传统不平衡推力法降低明显;滑坡中部由于地形的锁固效应阻滑作用明显,在Ⅸ度地震下极易失稳.研究结果为滑坡地震动力稳定性评价提供了方法.

The Application of the Modified Unbalanced Thrust Method to the Dynamic Stability Analysis of Earthquake Landslide

The unbalanced thrust method is one of the main research methods for the stability evaluation of the geological hazard of the landslide caused by the earthquake. The traditional unbalanced thrust method deals with seismic loads using single-valued inputs, regardless of the temporal and spatial variations of seismic waves during propagation in rock and soil. Aiming at this problem, based on the law of seismic wave propagation of landslide body, an imbalance considering multi-point seismic action thrust method is formed. Aiming at an landslide along a highway in Yunnan, the unbalanced thrust and safety factor under different seismic intensities are analyzed, and results show that: Considering the multi-point earthquake, the dynamic stability of the landslide is significantly lower than that of the traditional unbalanced thrust method; The middle part of the landslide has obvious anti-sliding effect due to the locking effect of the topography, and it is easy to be unstable under the IX degree earthquake. The research results provide a method for seismic dynamic stability evaluation of landslides.