黄土隧道新型支护结构施工力学性能分析

Analysis of Mechanical Properties of Innovative Support System in Loess Tunnels

为了满足特殊区段下黄土隧道的施工安全,强化初期支护使之尽早干预围岩应力状态尤为重要。基于对新型支护结构的探索,文章提出了钢-混组合结构支护体系,通过改变初期支护与二次衬砌的刚度比例,在施工初期提供较大的支护强度,从而减少松动荷载的产生。采用ANSYS建立三维地层开挖模型,从整体和局部受力的角度分析了组合结构钢架的承载特性及构件参数,并通过与常用支护体系进行施工对比分析,对各自的支护表现进行了评价。结果可为黄土隧道新型支护结构的研究提供参考。

To satisfy the construction safety of loess tunnels in special sections,it is important to strengthen the initial support to intervene in the stress state of surrounding rocks as soon as possible.Based on the exploration of a new support structure,this paper proposes the steel-concrete composite structure support system.By changing the stiffness ratio between the initial support and the secondary lining,the support strength can be provided at the initial stage of construction,so as to reduce the occurrence of loose pressure.ANSYS software is used to establish a threedimensional excavation model,the bearing characteristics and component parameters of the steel arch of the compos⁃ite support structure are analyzed from the perspective of the overall and local forces,and the supporting perfor⁃mance is evaluated through comparison with the common support system.The results can provide reference for the study of the new support structure of loess tunnels.