利用变分法探索地震作用隧道掌子面破坏形式

发布时间：2018-08-10 07:29

【摘要】：介绍基于变分法给出地震作用下隧道掌子面坍塌破坏极值曲线解析表达式的方法。首先建立隧道开挖纵向参考平面,通过引入地震系数k给出地震作用下掌子面坍塌破坏块体拟静力计算模型,然后由Hoek Brown破坏准则及关联流动给出破坏块体的内力耗散功率,从而根据上限定理建立关于掌子面破坏曲线的泛函,再由Euler Lagrange方程得到相应破坏极值曲线的非线性偏微分方程,最后给出B=0.5时掌子面破坏极值曲线特解。经与数值分析对比表明解析结果在预测掌子面前方最远距离zmax与数值结果较为一致,但破坏区域偏大。亦探讨了滑动方向角?与掌子面压力T?等参数变化对破坏极值曲线形状的影响。分析表明:该方法预测地震作用下掌子面破坏曲线的具体表达式可以较为简单且有效准确的反映掌子面前方区域受扰动特征,亦可以作为地震多发区隧道施工风险评价定量依据之一。
[Abstract]:Based on the variational method, the analytical expression of the extreme value curve of tunnel face collapse under earthquake action is introduced. Firstly, the longitudinal reference plane of tunnel excavation is established, and the pseudo-static model of collapse and failure block under seismic action is given by introducing the seismic coefficient k, and then the internal force dissipation power of the damaged block is given by Hoek Brown failure criterion and associated flow. According to the upper bound theorem, the functional of the metacarpal failure curve is established, and then the nonlinear partial differential equation of the corresponding damage extreme curve is obtained from the Euler Lagrange equation. At last, the special solution of the metacarpal failure extreme value curve when B = 0.5 is given. The comparison with the numerical analysis shows that the analytical results are consistent with the numerical results in the farthest distance zmax in front of the predicted face, but the damage area is larger. The angle of sliding direction is also discussed. With palm pressure? The influence of isoparametric change on the shape of failure extremum curve. The analysis shows that the concrete expression of the failure curve of the face of the palm under earthquake action can reflect the disturbance characteristics of the front area of the face of the palm more simply and accurately. It can also be used as a quantitative basis for risk assessment of tunnel construction in earthquake prone areas.
【作者单位】：西安理工大学水利水电学院;西安理工大学土木建筑学院;中国电力工程顾问集团西北电力设计院;
【基金】：国家自然科学基金青年基金项目(51409208) 中国博士后基金项目(2014M562524XB)
【分类号】：U452.28

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