三维矢量和方法在桥址岸坡稳定性分析中的应用

矢量和安全系数法物理意义明晰，是评价边坡稳定性的一种重要工具。以某顺层桥址岸坡为例，考虑凝灰岩软弱夹层和卸荷裂隙的不利组合，通过极限平衡方法得到了岸坡的最危险滑面。建立了考虑主要地层分布三维地质力学模型，通过三维矢量和分析方法对不利滑面进行分析，运用潘家铮最大最小原理确定三维矢量和安全系数的计算方向，对桥址岸坡在自重、桥基荷载、地震作用、桥基荷载和地震联合作用这４种工况下的稳定性进行了分析，结果表明岸坡的安全系数均满足稳定性要求。三维矢量和安全系数法与二维极限平衡法评价岸坡稳定性的结果一致性较好，为大型边坡工程的三维计算提供了参考。

Bridge Bank Slope Stability Analysis Based on Three-Dimensional Vector Sum Factor Methods

Vector sum factor of safety(VFOS)is an important way to explore the slope stability.By taking the bank slope of a bedding bridge site as an example,the unfavorable combination of tuff interlayer and unloading crack is considered in this paper.The most dangerous sliding surface of the slope is obtained by the limit equilibrium method,and the 3 D geomechanical model considering the main stratum distribution is established.The sliding surface is analyzed by VFOS.The direction of calculation is determined by using the Panjiazheng’s extremum principle.The stability of the bank slope of the bridge site under the four working conditions of dead weight,bridge foundation load,seismic action,bridge foundation load and combined seismic action is analyzed.The positive results obtained by this method are in good agreement with the results obtained by the two-dimensional limit equilibrium method.