某铁路隧道衬砌拱腰拉裂拱顶压溃病害原因探析

隧道衬砌缺陷致害研究是当前热点,对衬砌病害产生原因进行探析对隧道施工及设计来说尤为重要。通过结合相关资料、建立FLAC2D二维模型对某隧道出现的拱腰拉裂、拱顶压溃病害原因进行初探,研究结果表明:(1)拱顶背后存在空洞是引起隧道衬砌拱腰拉裂、拱顶压溃病害的主要原因。(2)拱顶背后存在空洞将引起衬砌受力发生显著变化,具体表现为拱部由衬砌背后无脱空工况下的洞内侧受拉转变成洞外侧受拉,且拱顶衬砌内表面处出现压应力集中。

An Approach to Lining Arch Crown Collapse and Haunch Crack in a Railway Tunnel

The lining haunch crack and arch crown collapse takes place in the railway tunnel and impacts directly the safety of the tunnel structures. With reference to the relative information and based on the researches on the causes,a two-dimensional numerical simulation model is built with FLAC2 D software to analyze the causes of haunch crack and arch crown collapse. The research results show that( 1) holes behind the vault are the main factor causing haunch crack and arch crow collapse;( 2) the presence of cavity behind vault causes the change of lining stress significantly,which results in lateral tension of the hole turning from inner pull when there is no cavity behind the lining,meanwhile,compressive stress concentration appears at the inner surface of the arch crown lining.