Fire-Induced Concrete Cracking in Immersed Tunnels: Experimental Investigation and Depth Analysis

The safety of hydraulic structures is not solely dependent on the structural bearing capacity but also on the potential for concrete cracking, which is susceptible to occur during a fire. To investigate the concrete cracking of an immersed tunnel under fire, a fire test was conducted on two tubes of a scaled immersed tunnel. Various monitoring methods were employed to detect concrete cracks during the fire test. By integrating the temperature field distribution in concrete and the behavior of concrete cracking, an analysis of the depth of concrete cracking in the immersed tunnel under fire was conducted. The primary findings are as follows: