Please polish the following paragraph according to the style of SCI journalsWhen a fire occurs in an immersed tunnel during the heating stage the thermal expansion of the inner surface will cause the

In the event of a fire in an immersed tunnel, the heating stage induces thermal expansion of the inner surface, leading to the pulling and cracking of concrete on the outer surface. These cracks propagate rapidly, potentially reaching significant depths. Through-cracks in the concrete pose a direct threat to the safety of the immersed tunnel by allowing seawater leakage. Additionally, even in the absence of through-cracks, concrete cracking exposes rebars to the marine chloride environment, accelerating their corrosion and reducing the service life of the tunnel. Therefore, it is crucial to consider the potential for concrete cracking due to thermal strain in the fire resistance design of immersed tunnels