基于不完全拱效应的隧道预处理机制与计算方法

发布时间：2018-05-06 13:26

本文选题：隧道工程 + 不完全拱效应　；参考：《岩石力学与工程学报》2017年06期

【摘要】：隧道开挖中,掌子面超前核心土的变形同样会使其周围产生拱效应,但该种拱效应不同于后方已开挖区域周围的拱效应,称之为不完全拱效应。不完全拱效应的发挥与预收敛变形和挤出变形有很大的关系,基于不完全拱效应提出了超前核心土周围围岩压力的计算公式,此公式与太沙基公式的不同在于考虑了预收敛变形对围岩压力的影响,并在黏性土的推导中考虑了非垂直滑移面效应,假定破裂面与垂直方向存在夹角θ。算例分析显示,随着预收敛变形的增加拱顶土压力的变化可分为近线性快速下降、缓慢下降及稳定阶段,计算土压力随内摩擦角、埋深比及黏聚力的增大而减小,且在黏性土中随破裂面倾角的增大而增大。在此基础上,推导了计算基于新意法的超前核心土加固参数的理论计算公式,结合算例验证了理论公式的适用性,该公式计算简单,便于理解,可用于新意法的初步设计阶段。
[Abstract]:In tunnel excavation, the deformation of the core soil in front of the palm surface will also cause the arch effect around it, but the arch effect is different from the arch effect around the excavated area in the rear area, which is called incomplete arch effect. The exertion of incomplete arch effect is closely related to preconvergent deformation and extrusion deformation. Based on the incomplete arch effect, a formula for calculating the surrounding rock pressure around the leading core soil is proposed. The difference between this formula and the Terzaghi formula is that the influence of preconvergent deformation on the surrounding rock pressure is considered, and the non-vertical slip plane effect is considered in the derivation of the clay, and the angle 胃 between the fracture surface and the vertical direction is assumed. With the increase of preconvergent deformation, the variation of earth pressure of arch roof can be divided into three stages: near linear rapid decline, slow decline and steady stage. The calculated earth pressure decreases with the increase of internal friction angle, burying depth ratio and cohesive force. Moreover, the inclination of the fracture surface increases with the increase of the inclination of the fracture surface in the clay. On this basis, the theoretical calculation formula for calculating the parameters of leading core soil reinforcement based on the new idea method is derived. The applicability of the theoretical formula is verified by an example. The formula is simple and easy to understand, and can be used in the preliminary design stage of the new meaning method.
【作者单位】：长安大学公路学院;北京城建设计发展集团股份有限公司;
【基金】：国家自然科学基金面上项目(51478044,51678062)~~
【分类号】：U455.4

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