Experimental and Numerical Investigation of Underwater Tunnel Subjected to Explosions

The dynamic response of underwater tunnels subjected to explosions is crucial for structural disaster prevention and protection measures. This study investigates the dynamic behavior of underwater tunnel segments subjected to explosions using both experimental and numerical methods. The results indicate that shock waves lead to surface truncation at the water’s surface. Experimental peak pressures were in close alignment with theoretical predictions by Cole, with an error of 20%. The tunnel surface showed an uneven pressure distribution, peaking on the front surface at 1.626–1.716 times the free field pressure. The impulse response to explosions displayed a step-like pattern. Tunnel motion was categorized into three phases: Rapid structural deformation, large amplitude structural vibration and structural flutter. Numerical analysis revealed an exponential peak pressure distribution, with a rapid decrease in the range up to [Formula: see text] and stabilization beyond that angle. A formula for tunnel pressure coefficient was proposed for evaluating loads under explosions.