泥石流汇流槽可靠度分析

Reliability analysis on converge-trough for debris flow

汇流槽是泥石流治理工程中常用的工程措施之一。文章基于汇流槽的倾倒破坏、滑移破坏及地基破坏模式,通过对汇流槽设计影响强烈的岩土参数、几何特征、荷载因素等敏感因子的求解方法及分布特征分析,从汇流槽的抗倾稳定、抗滑稳定和基底应力要求三方面建立极限状态方程。对于每个极限状态方程,在泰勒级数对非线性极限状态方程线性化后,运用一次二阶矩的理论,先假定失效点P,求解出相应的均值和方差。然后根据可靠的定义,得到相应的可靠度指标,通过迭代法求解真正失效点的可靠度指标βi。最后根据3个状态方程相互独立的假定,得出整个结构的可靠度指标β。该方法在平川泥石流防治工程中得到了成功的运用。这对于可靠度设计方法在泥石流防治工程中的运用进行了有益的探讨。

Converge-trough is usualy applied to control debris flow. Based on converge-trough＇ s three destructive patterns such as toppling failure, slipping failure and fundus stress insufficiency, integrated with analyzing on the geotechnical parameter, geometrical character, load etc. sensitive to converge trough design, three utmost equations are built up met convergetrough resisting toppling and slipping and fundus stress requirements. After those nonlinear utmost equations being linearized by using Thaler series, based on the supposed invalidation spot P…＊ , applying First-order Second-moment method in each tumost equation, average value and covariance are gained. Then according to the definition of reliability, the paper resolves the corresponding reliability index. The real invalidation spot is found by iterative method and the reliability index βi is solved. Finally, the whole reliability of the structure index β is obtained on the assumption of the three state equations being irrelated. The design method through reliability is applied to control debris flow in Pingchuan converge-trough triumphantly, which is useful reference in the engineering controlling debris flow.