Cracking Mechanism and Safety Analysis of Highway Tunnel Secondary Lining

Xin ZHENG1, Zhiyun DENG2

1School of Civil Engineering and Architecture, Chongqing Jiaotong University, Chongqing, CHINA

2College of Civil Engineering, Chongqing University, Chongqing, CHINA

Abstract: Tunnel lining crack damage affects the overall stability of lining structure. It makes the carrying capacity of tunnel lining abate, seriously threatening the safety of tunnel traffic, shortening the maintenance cycle and service life of the tunnel. Based on the lining crack damage mechanism analysis, the deformation mechanism of surrounding rock and the mechanism of lining stress and deformation are studied in this article. Combined with five highway tunnel projects in Chongqing, which are completed and accepted, ｌｏａｄ structure method is adopted to establish the calculation model. The safety of insufficient arch lining thickness and disengaging defects, insufficient wall lining thickness and disengaging defects, different parts of insufficient lining thickness and disengaging defects are analyzed respectively. The study not only provides reference for causes of lining crack damage, but also lays the foundation for prevention and reinforcement repair of the follow- up of tunnel lining crack damage.

Keywords: Crack Damage; Deformation of Surrounding Rock; Owe Thickness; Disengaging; Safety Analysis