强度折减最短路径在浅埋隧道极限分析的存在性研究

发布时间：2018-04-28 20:49

本文选题：强度折减 + 最短路径　；参考：《湖南大学学报(自然科学版)》2017年09期

【摘要】：将强度折减最短路径理论,应用于有限元强度折减与极限平衡强度折减分析中,假定黏聚力和内摩擦角按不同折减系数进行强度折减,结合具体算例探讨在双参数强度折减时黏聚力与内摩擦角的合理折减比例,同时考虑隧道埋深与洞跨比值的影响,证明了在浅埋隧道极限分析中强度折减最短路径存在的合理性.研究结果表明:在浅埋隧道强度折减最短路径分析中,随着黏聚力与内摩擦角折减比例λ=Fc/Fφ的增大,黏聚力的折减系数逐渐增大,内摩擦角的折减系数逐渐减小,折减路径长度先减小后增大,两者近似服从抛物线分布,证明存在最短折减路径;同时在强度折减最短路径下,黏聚力的折减幅度要大于内摩擦角,且随着埋深的增加,两者折减幅度逐渐接近.
[Abstract]:The theory of the shortest path of strength reduction is applied to the analysis of finite element strength reduction and ultimate equilibrium strength reduction. It is assumed that cohesion force and internal friction angle are reduced according to different reduction coefficients. The reasonable reduction ratio of cohesion force and internal friction angle is discussed in the case of double parameter strength reduction, and the influence of tunnel depth to tunnel span ratio is considered. It is proved that the shortest path of strength reduction is reasonable in the limit analysis of shallow tunnel. The results show that in the analysis of the shortest path of strength reduction of shallow tunnel, with the increase of cohesion and internal friction angle reduction ratio 位 Fc / F 蠁, the reduction coefficient of cohesion and internal friction angle gradually increases, and the reduction coefficient of internal friction angle decreases gradually. The length of the reduction path decreases first and then increases. The distribution of the two paths is similar to that of parabola, which proves that there exists the shortest reduction path, and at the same time, under the shortest path of strength reduction, the reduction of cohesive force is larger than that of internal friction angle, and with the increase of buried depth, the reduction of cohesive force is larger than that of internal friction angle. The rate of reduction between the two is gradually approaching.
【作者单位】：中南大学土木工程学院;
【基金】：国家自然科学基金资助项目(51378505)~~
【分类号】：U451

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