特长公路隧道风机房典型双T型结构稳定性分析

隧道空间交叉结构受力特性及其稳定性是近年来长大公路隧道亟待解决的关键技术问题。通过对隧道风机房典型双T型交叉结构三维有限元数值模拟，研究了在双T型交叉结构建设过程中围岩的变形规律、影响范围以及结构自身的受力特性等。结果表明:随着隧道开挖，交叉结构受到的影响程度为:叠加区 > 影响区 > 普通区；小断面中围岩与衬砌间主要作用为抗剪，大断面中围岩与衬砌间主要作用为抗拉；结构存在一定的偏压现象，在对交叉结构进行设计施工时要注意对偏压部分进行局部加强。

Stability Analysis of Typical Double T-shaped Structure of Fan Room in Extra-long Highway Tunnel

The force characteristics and stability of the tunnel space crossed structure are the key technical problems that need to be solved in the long highway tunnels in recent years. Based on three-dimensional finite element numerical simulation of typical double T-shaped crossed structure of fan room in tunnel, this paper studies the deformation law of the surrounding rock, the scope of influence and the force characteristics of the crossed structure during the construction of the double T-shaped crossed structure. The results show that the degree of the cross-structure influence along with the tunnel excavation is as follows:superimposed area > affected area > common area, and the main action between the surrounding rock and lining in small section is shear resistance, while that between surrounding rock and lining in large section is tensile resistance. The structure has a certain bias phenomenon. Therefore, it is necessary to pay attention to the partial strengthening of the bias portion during design and construction.