To investigate the deformation law of submerged floating tunnel (SFT) subjected to underwater explosion-moving load

the underwater explosion process was simplified to the stages of shock wave load and bubble motion based on the Cole shock wave load semi-empirical formula and Vernon bubble motion equation. The Grade I vehicle load of highway was simplified to the moving load sequence. A dynamic model of SFT considering underwater explosive load

moving load

and fluid effect was established based on the D’Alembert’s principle. The four order Runge-Kutta method was adopted to solve the differential equations of motions

and the proposed model was verified by using the existing data and formulas. Finally

the effects of explosive load and moving load on the deformation of the tunnel were discussed. Results show that the impact factor  could greatly promote the increase in the maximum displacement of SFT. Compared with =0.1

when the impact factor increased by 2 times and 4 times

the maximum displacement of the tunnel increased by 4 times and 10 times under explosive load alone. With the increase in the explosive amount

the bubble load frequency increased exponentially

with the increase in the water depth of the explosion point

the bubble load frequency decreased in inverse proportion. In the cases of different explosive amounts and water depths

the bubble load frequencies were all less than 3 Hz

which was close to the low-order frequency of the tunnel and easily led to resonance. Under the action of underwater explosion and moving load

the maximum displacement of SFT was affected by the combined effect of the position and speed of the moving load

and the explosion was more harmful to the tunnel when the vehicle ran at the fastest speed until the mid-span.