Structural damage and waterproof performance analysis of composite segment in #br#
large section shield tunnels under post-earthquake fire
Zhang Wenjun1，2，3 Lai Taotao1，2 Zhang Gaole1，2
1. School of Civil Engineering, Tianjin University, Tianjin 300354, China；
2. Key Laboratory of Coast Civil Structure Safety of the Education Ministry, Tianjin University, Tianjin 300354, China；
3. State Key Laboratory of shield Machine and Boring Technology, Zhengzhou 450001, China
Abstract： In order to study the structural damage and the loss of waterproof performance of large-section shield tunnel composite segment under post-earthquake fire, the finite element calculation software abaqus is used to establish the three-dimensional solid model of a composite segment and straight bolt joint and the two-dimensional numerical model of gasket compression. The stiffness damage distribution of concrete of composite segment at bolt holes and yield distribution of steel plate of a composite segment at bolt holes under earthquake and earthquake-fire coupling are analyzed. The loss of waterproof performance of tunnel gasket under earthquake and earthquake-fire coupling is calculated. The results show that: when RABT heating curve is used to simulate fire, the stiffness damage of concrete at bolt holes caused by a heavy earthquake exceeds 90% after the fire, while the rest exceeds 90% except the stiffness damage of concrete at the top of bolt holes under a moderate earthquake after the fire-Fire causes the steel plate at bolt hole to yield. The waterproof gasket can still maintain good waterproof performance after the combined action of moderate earthquake and fire, but the waterproof performance is completely lost after the combined action of heavy earthquake and fire.
