Research methods: The analysis and research were made on engineering geology, design, construction and the result of comprehensively physical exploration after collapse. The analysis of simulation computing and research were made on the behavior of engineering mechanics for treating collapse by drafted scheme. The situations of collapse treatment and optimization were presented.
Research results: The main reasons for tunnel collapse were found out through analysis, namely due to complicated engineering geology and no laying secondary lining. It was demonstrated that the scheme of collapse treatment was reliable and treatment measure was complete with high safe level. It was shown the treatment of collapse was successful.
Research conclusions: It was necessary to strengthen geological exploration and prediction, modify the relevant construction rules in time, and solve the problems existed in construction in time and establish scientific decision's system in order to prevent the collapse happening.
2006, Vol. 23 
