Some construction experiences of a motorway road tunnel collapse

摘要

The focus of the paper is a motorway tunnel collapse, built by using the NewAustrian TunnelingrnMethod (NATM). The project consists of four separate tunnels in total 5419 meters long with a cross section arearnof 101m~2. The longest double tunnel “named A” was 2×1,356m long, and a collapse occurred in the middlernof the both tubes at dawn of 24 July 2008. The incidence affected 113m section of the tunnel in the east tubernand 90m in the west tube. It stretched further later to 73 meters in the two tubes. The evacuation of the tunnelrnwas successfully completed as the collapse had been preceded by loud cracking noises and visible deformations.rnDetailed analyses were carried out on tunnels in order to understand the reasons of the collapse, and to ensurernthe possibility of further construction.