黏性地层中深埋直墙拱形隧道的支护压力及稳定性

发布时间：2018-04-20 07:48

本文选题：深埋隧道 + 剪切破坏理论　；参考：《岩土工程学报》2017年11期

【摘要】：在剪切破坏理论基础上采用极限分析法对黏性地层中深埋直墙拱形隧道展开研究。首先基于加载试验提出了破裂区的理论模型,考虑隧道侧面剪切楔形体的双滑裂面作用建立了侧压力表达式,得出侧压力及竖向支护压力的近似解,并提出了隧道侧压力与竖向土压力相互作用理论。根据剪切楔形体的稳定建立无支护深埋直墙拱形隧道的稳定性定量判别条件,得出极限承载力近似解。定义了基于极限分析法的稳定安全系数,并分析深埋隧道稳定性的影响因素。研究结果表明:本文提出的破裂区理论模型、极限承载力值与试验结果接近;基于双滑裂面作用的竖向支护压力、侧压力显著小于传统理论值;在良好地层中,拱形隧道极限状态下的竖向支护压力越小则侧压力越大,侧压力或侧压力系数?越大则竖向支护压力越小;黏聚力是无支护的深埋直墙拱形隧道稳定的必要条件稳定安全系数K随黏聚力、内摩擦角的增大而增大,随隧道跨度、高度的增大而减小;黏聚力对K的影响比内摩擦角大,跨度对K的影响比高度大,而埋深越大对深埋隧道稳定安全系数的影响越小。
[Abstract]:On the basis of the shear failure theory, the limit analysis method is used to study the deep buried straight wall arch tunnel in the viscous stratum. Firstly, the theoretical model of the fracture zone is put forward based on the loading test, and the lateral pressure expression is established considering the double sliding surface of the shear wedge in the side of the tunnel, and the approximate solution of the lateral pressure and the vertical support pressure is obtained. The theory of the interaction of tunnel side pressure and vertical earth pressure is put forward. Based on the stability of the shear wedge shape, the quantitative criterion for the stability of the unsupported deep buried straight wall arch tunnel is established, and the approximate solution of the ultimate bearing capacity is obtained. The stability safety factor based on the limit analysis method is defined and the influence factors of the stability of the deep buried tunnel are analyzed. The results show that the theoretical model of the fracture zone proposed in this paper is close to the test results, and the lateral pressure is significantly smaller than the traditional theoretical value based on the vertical support pressure based on the double sliding surface. The greater the vertical support pressure is, the greater the lateral pressure is, the greater the side pressure or side pressure coefficient is, the greater the coefficient of side pressure or side pressure is greater in a good stratum. The smaller the vertical support pressure is, the cohesive force is the necessary condition of stability of the unsupported deep buried straight wall arch tunnel. The stability safety factor K increases with the cohesion, the increase of the internal friction angle and the increase of the tunnel span and height; the influence of cohesive force on the K is larger than the internal friction angle, and the influence of the span to the K is larger than that of the depth, and the deeper the buried depth is, the deeper the deep buried tunnel is buried. The lower the influence of the stability safety factor of the channel.

【作者单位】：中交铁道设计研究总院有限公司;
【分类号】：U451

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