基于双极坐标法浅埋圆形隧道围岩非线性弹塑性分析  

Nonlinear elasto-plastic analysis of surrounding rock for shallow buried circular tunnel based on bipolar coordinate method

作　　者：王岩 邹金锋[2] 邹飞[3] 

机构地区：[1]中铁十七局集团第一工程有限公司,山西太原030000 [2]中南大学土木工程学院,湖南长沙410075 [3]贵州省交通规划勘察设计研究院股份有限公司,贵州贵阳550081

出　　处：《中南大学学报（自然科学版）》2017年第11期3077-3083,共7页Journal of Central South University:Science and Technology

基　　金：贵州省交通运输厅科技项目(2015122046)

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。Considering the nonlinear characteristics of the rock mass, stress distribution and plastic region of surroundingrock around a shallow tunnel in semi-infinite space were studied by using bipolar coordinate system. The calculationmodel for shallow circular tunnel was established in the continuous, isotropous and homogeneous rock massessemi-infinite space. The solution for surrounding rocks was regarded as a semi-infinite plane problem, and the plane waspartitioned along the curve trajectories of the bipolar coordinate. Under the action of uniform load on ground surface andradial support force of tunnel, the closed-form solution for stress distribution was deduced based on the generalizedHoek？Brown failure criterion. And the calculation approaches for plastic radius and the shape of plastic zone around atunnel and the critical internal support pressure were obtained. By using numerical method, the influences of thegeological strength index, internal support pressure, surface loading and buried depth of tunnel on plastic radius, plasticzone and stress distribution of surrounding rocks around shallow circular tunnel were discussed. The results show that thepresented method is proved to be effective by being compared with the methods of linear failure criterion. The comprisonresults will be shown later that the differences between them are very close.

关 键 词：浅埋隧道 无限半空间 塑性区域 应力分布 广义Hoek-Brown屈服准则 

分 类 号：TU41[建筑科学—岩土工程]