| description abstract | The failure of Shanghai Metro Line 4 in 2003 was one of the most striking accidents in the history of subway construction in China. It involved the first breach failure of a cross passage being mined by an artificial ground-freezing method, followed by a massive ingress of water and soil, dramatic ground subsidence, rapid sinking of existing structures, failure of the adjacent dike and floodwall along the Huang-Pu River, flooding of the site, and collapse of buildings and metro tunnels. The accident directly resulted from failure of the cross passage being excavated within a confined aquifer. In the beginning, artesian water broke the frozen mass; then, water and soil gushed into the cross passage and metro tunnels. As a result of massive ground loss, the ground level underwent significant subsidence up to 4 m and those preexisting structures were damaged. Inherently, this event was a typical project management failure, associated with a number of procedural and ethical blunders. To rebuild the destructive failure case, this paper outlines the design and construction for the cross passage along with the geological conditions, describes those preceding events incurring the failure, depicts the catastrophic scene, and introduces the postfailure emergency responses and disaster-relief measures. Finally, technical, procedural, and ethical factors leading to the failure are summarized. | |
