边坡稳定分析的相对失稳加速度方法

Relative instability acceleration method for slope stability analysis

边坡稳定分析是土力学的经典课题,通过稳定分析能够得到边坡的安全系数。但最小安全系数对应的临界滑动面不一定是最先发生滑动的破坏面,失稳加速度临界滑动面则可能最先滑动。失稳加速度方法可以用统一的原理计算边坡和隧洞等所有具有临空面的结构的稳定性;可以利用常规极限平衡法的假定条件进行计算,也可以利用有限元等数值方法的应力计算成果;可以计算失稳加速度,也可以以失稳加速度的模最小来计算安全系数,此时也相当于一种特殊的模式识别方法。本文对失稳加速度方法的提出过程及主要原理进行系统总结,并将其推广到相对失稳加速度和相对安全系数,放松了约束条件,使得它可以具有更加广阔的应用前景。

Slope stability analysis is a classical subject of soil mechanics, through which the safety factor of a slope can be obtained. However, the critical slip surface corresponding to the minimum safety factor is not necessarily the first failure surface to slide, while the one relating to instability acceleration possibly slides first. The theory of instability acceleration is applicable to all structures with free faces such as slopes and tunnels;for the calculations, we can use the conventional assumption of the limit equilibrium method, or a stress analysis via a numerical method such as the finite element method. Besides instability acceleration, traditional safety factors can also be calculated through minimizing the modulus of instability acceleration, a case similar to the special pattern recognition method. This paper sums up the historic evolution and main principles of the instability acceleration method. And we extend the theory to the calculation of relative instability acceleration and relative safety factors, relax its related constraints,and allow it to have a wider application prospect.