Scattering of Plane SV Waves by Underwater Tunnel

Abstract

Accounting for fluid-solid coupling in saturated underwater soils, the scattering problem of underwater tunnel under plane SV-wave incidence is investigated by using the Fourier-Bessel series expansion method of wave function. Numerical examples analyze the effects of incident wave angle, frequency, tunnel burial depth, and porosity on displacement at the water-soil interface and dynamic stress concentration on the tunnel surface. The study shows that vertical wave incidence (θ_is = 0°) results in symmetric displacement and stress distribution at the water-soil interface and tunnel surface. With increasing incident angle, horizontal displacement decreases, vertical displacement increases, and dynamic stress on the tunnel surface peaks at a certain angle. Higher incident frequency increases the complexity of displacement and stress distribution, with more wave crests, troughs, and larger amplitudes. In shallow burial conditions, displacement and stress concentration above the tunnel are most pronounced, and the effect of increased porosity on displacement and stress depends on incident frequency.