黄土隧道衬砌背后空洞对隧道衬砌结构影响分析

衬砌裂损是隧道病害中常见的问题，也是严重威胁结构安全的一个重要因素。文章针对铁路运营隧道病害的检测结果，对衬砌背后空洞进行平面弹塑性计算分析，得出不同位置、不同大小的空洞以及空洞群对结构各截面受力及位移影响的系统认识，明确提出衬砌结构与围岩结合的不紧密性是恶化衬砌受力条件、造成围岩进一步松动、进而造成衬砌裂损的一个重要原因;还对直墙式及曲墙式衬砌所受到的不同影响进行了比较分析，认为曲墙式衬砌拱部结构能较好地将内力传递给边墙，由边墙部分承受较大的水平抗力，优化了整体结构的受力，从而降低背后空洞对衬砌结构的影响。通过对计算结果的系统分析和研究，合理解释了实际检测中的问题。

Analysis on Cause of Liner Rear Cavity Failure of Ocher Tunnel Lining

The lining＇s crack is an ordinary problem in tunnel disaster as wall as an important factor of influencing structure＇s safety. The paper calculates and analyzes the cavities behind the lining with elastic-plastic FEM method based on inspection results of the railway tunnel＇s disaster. The analysis educes a systematic cognition on the effect to linings safety factor by different positions,different size cavities and cavity groups, and puts forward sharply that the gapping between lining and surrounding rock is the important cause which worsens the linings stress and looses the surrounding rock. The paper also compares the different effects on the straight wall lining and the bent wall lining,and considers that the bent wall lining can transfer the load to the sidewall better, thereby reduces the influence of the back cavities. And then, this paper gives reasonable explanations to problems of the inspection.