基于双极坐标法浅埋圆形隧道围岩非线性弹塑性分析

发布时间：2018-11-26 20:36

【摘要】：考虑围岩的非线性特性,采用双极坐标系研究弹塑性半无限空间内浅埋隧道围岩应力分布和塑性区域。在连续、均匀和各项同性的无限半空间下建立浅埋隧道开挖模型,围岩求解问题可当作半无限平面问题,并且将平面依据双极坐标曲线划分。在地表均布荷载和隧道径向支护力作用下,基于广义Hoek-Brown强度准则推导出半无限空间内水平圆形隧道围岩的弹塑性应力解析解以及塑性半径、塑性区域范围和隧道临界支护力计算方法。最后,通过数值计算,分析地质强度指标、内部支护力、地表荷载和隧道埋深的变化对浅埋隧道围岩的塑性半径、塑性区域形状和应力分布的影响规律。通过与其他基于线性强度准则下的应力计算方法进行对比,验证本文方法的有效性。之后的结果显示,两种准则计算结果差距十分小。
[Abstract]:Considering the nonlinear characteristics of surrounding rock, the stress distribution and plastic region of surrounding rock of shallow buried tunnel in elastic-plastic semi-infinite space are studied in bipolar coordinate system. In this paper, the excavation model of shallow tunnel is established in continuous, uniform and homogeneous infinite half-space. The surrounding rock can be solved as a semi-infinite plane problem, and the plane can be divided according to the bipolar coordinate curve. Based on the generalized Hoek-Brown strength criterion, the elastic-plastic stress analytical solution and plastic radius of surrounding rock of horizontal circular tunnel in semi-infinite space are derived under the action of uniform surface load and radial support force. The method of calculating the plastic region and the critical support force of the tunnel. Finally, the influence of geological strength index, internal support force, surface load and tunnel depth on the plastic radius, shape of plastic region and stress distribution of shallow tunnel surrounding rock are analyzed by numerical calculation. Compared with other stress calculation methods based on linear strength criterion, the effectiveness of this method is verified. The results show that the difference between the two criteria is very small.
【作者单位】：中铁十七局集团第一工程有限公司;中南大学土木工程学院;贵州省交通规划勘察设计研究院股份有限公司;
【基金】：贵州省交通运输厅科技项目(2015122046)~~
【分类号】：U451.2

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