Piping Failure of a Metro Tunnel Construction

In this paper, the forensic investigation of a subway tunnel construction failure occurred in Kaohsiung, Taiwan is presented. The studied construction failure occurred during a cross-pass tunnel excavation of a shield tunnel construction work of the Kaohsiung Mass Rapid Transit system, and had resulted in severed tunnel collapse and extensive ground failure that even reached to ground surface 30 m above the tunnel depth. In order to investigate such a serious construction failure, particular soil testing programs and geophysical testing methods were carried out to access the possible failure scenario of the investigated case. Information presented in this paper is hoped to be helpful to improve engineers’ knowledge for preventing similar construction risks.