坡向加速度法在边坡稳定分析中的应用

Application of Slope Aspect Acceleration Method inSlope Stability Calculation

边坡稳定是一个经典而普遍的岩土力学问题,也一直是岩土工程分析的热点。为克服强度折减法中折减系数与工程实际强度不符的失真现象,真实反映边坡地震动载失稳的实际情况,通过引入坡向加速度,提出一种操作简单、物理意义明确的边坡稳定计算方法,即坡向加速度法。该方法通过不断增加坡向加速度直至边坡失稳为止,由极限平衡的思想求得安全系数。通过算例,将该方法与传统极限平衡法和有限元强度折减法进行对比,对强度变化敏感性进行分析。结果表明:坡向加速度法计算所得的安全系数与极限平衡法所得的安全系数非常接近,塑性区与强度折减法塑性区基本一致,计算结果准确,而且操作简单无需假设滑动面;与坡向离心法相比,坡向加速度法计算得到的安全系数更精确且适用于非均质的边坡稳定分析,说明该方法在边坡稳定分析中的适用性和优越性。因此,可将坡向加速度法应用于边坡稳定性分析,其结果可供工程应用参考。

Slope stability is an ancient and common problem and has always been a hot spot in geotechnical analysis.In order to overcome the inconsistency between engineering practice and reduction factor in strength reduction method,and truly reflect the instability of slope under seismic loading,we present a convenient method of calculating slope stability with explicit physical meaning—slope acceleration method.The method obtains the safety factor from the limit equilibrium idea by increasing the slope acceleration until the slope is unstable.Through some calculation examples,we compared the results of safety factor among different methods(including traditional limit equilibrium method and finite element strength reduction method),and analyzed the sensitivity of strength change.Results indicate that the safety factor obtained by the slope acceleration method is close to that by limit equilibrium method,and the plastic zone consistent with that of the strength reduction method with no need to assume the sliding surface.Compared with the slope centrifugal method,the present method obtains a more accurate safety factor and is more suitable for inhomogeneous slope.The present method is proved applicable and superior in slope stability analysis.