重叠下穿既有人防洞的公路隧道力学特性及稳定性分析

Mechanical Characteristics and Stability Analysis of a Highway Tunnel Overlapped Passing under the Existing Civil Air Defense Tunnel

文章基于新建公路隧道重叠下穿既有人防洞的实际工程,利用有限差分软件FLAD3D,对比研究了有、无人防洞工况下公路隧道的力学特性,并分析了公路隧道的稳定性。结论如下:公路隧道重叠下穿既有人防洞时,人防洞的存在对公路隧道初期支护和二次衬砌拱部应力状态的影响较大,对边墙及仰拱应力状态的影响较小;人防洞的存在对新建公路隧道拱顶沉降有一定影响,但随着公路隧道支护的施作其影响作用减弱;人防洞的存在对新建公路隧道仰拱隆起的影响始终较小;无论人防洞是否存在,新建公路隧道的受力和位移均处于安全范围内。研究成果可为类似工程的设计和施工提供参考。

Based on the actual project of new highway tunnel overlapped passing under the existing civil air defense tunnel,the mechanical characteristics of highway tunnel with and without civil air defense tunnel were studied by using finite difference software FLAD3 D,and the stability of highway tunnel was also analyzed.The conclusions are as follows:when the highway tunnel overlapped passing under the existing civil air defense tunnel,the existence of the civil air defense tunnel has a great influence on the stress state of the arch of initial support and secondary lining of highway tunnel,and has a little influence on the stress state of side wall and inverted arch.The existence of civil air defense tunnel has some influence on the settlement of new highway tunnel vault,but the effect is weakened with the construction of highway tunnel support.The existence of civil air defense tunnel has a little influence on the inverted arch heaving of new highway tunnel.Whether there is a civil air defense tunnel or not,the stress and displacement of the new highway tunnel are within the safe range.The research results can provide reference for the design and construction of similar projects.