某隧道塌方原因分析及处理方案

Causation Analysis of Collapse of Some Tunnel and Treatment Measures

通过某隧道对塌方发生时各工作面状态及前期施工过程的追溯,指出应急抢险措施不当是导致塌方的直接原因,而一段时间以来各作业面纵向距离过长与质量缺陷是导致坍塌的根本原因;提出了以加强衬砌、周边围岩注浆、扩大拱脚及组合工法为技术要点的综合处理方案,并建议采用组合型钢形成多点斜撑的临时支撑布设方式。

Collapse of surrounding rock of a tunnel under construction is introduced in this paper.Based on the analysis of working face status and review of the construction process for several months,it has been shown that the improper emergency measures adopted were the direct cause for the collapse.However,improper longitudinal distances among the working faces and quality defects of the support structures were the root causes.After the causation study,an integrated treatment program has been proposed,including improving support parameters,grouting in the surrounding rock,reinforcing arch abutment and adopting combined engineering measures etc.Finally,multi-point inclined temporary support with I-beams has been also proposed.