Abstract��
Regarding a collapse event in the Shangpingge tunnel in Fujian province, corresponding treatment mea?
sures were proposed based on an analysis of the causes, and the strengh of the primary and secondary lining were verified after alteration using the load- structure method. It was concluded that unfavorable geological conditions,bad construction quality and an unsuitable excavation method are the major reasons for the tunnel collapse; a large bending moment of the primary and secondary lining occurs at the tunnel crown, haunch, arch foot and invert under the effect of the collapse load, and special attention should be paid to these postions during tunnel construction; and the minimum safety factor is 1.93 for dangerous cross-sections of the primary support and 2.43 for the secodary lining, which are larger than the values specified by the natioanl tunnel code, therefore meeting the requriements of engineering safety
2017, Vol. 54 