加筋路堤边坡稳定非线性有限元分析方法探讨

Discussion on Nonlinear Finite Element Stability Analysis Method of Reinforced Embankment Slope

针对极限平衡理论方法难以合理分析复杂结构边坡的事实,本文在非线性有限元方法的基础上,考虑了加筋路堤边坡内不同材料单元形式的本构模型,并在土-织物之间设置接触面单元,以模拟在接触面上可能产生的错动滑移。利用强度折减法进行稳定分析,为保证有限元迭代计算的收敛,引入弧长控制法自动调整土体强度参数的折减量,以求得精确的安全系数值。最后通过一路堤工程的计算分析,表明加筋后不仅可以改善坡内的应力分布,提高安全系数,而且使得最危险滑弧的形状大小及位置都发生改变,提高了整体稳定性,从而验证了本文方法分析加筋土坡的可行性。

In view of the fact that limit equilibrium theory method is used to analyze reasonably the complex structure slope with difficulty, based on nonlinear finite element method, this article considers the constitutive model of different material unit forms in reinforced embankment slope, and establishes the contact face element between the earth - fabric, which simulates the possibly moving and slipping in the contact face. The stability analysis was carried on with strength subtraction technique, in order to guarantee the finite element iterative computation convergence, the arc-length control method was introduced to automatically adjust the soil intensity parameter decrement, so as to obtain the precise safety factor. Finally, through an embankment project computation analysis, it is indicated that the reinforcement may improve the stress distribution in the slope and inerease the safety factor, moreover the reinforcement can cause changes of shape size and position of the nmst dangerous slippery are, and enhance the overall stability. Thus the paper proves that this method is feasible in analyzing the reinforced embankment slope.