A BEM investigation on the influence of underground cavities on the seismic response of canyons

Abstract

Two-dimensional site effects caused by cavities under topographical functions can considerably impact the seismic reaction of the ground surface. Due to the complexity of scattering issues by topographical features above subterranean cavity, few studies have been done in this field. In the present study, the seismic response of semisine-shaped canyons above a subterranean cavity (hole) of different dimensions, depths and locations is examined. The medium is assumed to have a linear elastic constitutive behavior exposed to vertically propagating incident SV and P waves. All calculations are performed using the direct boundary element technique in the time domain. It is observed that a cavity below a canyon can considerably change the ground response of the surface in different periodic bands. The seismic interaction between canyon and cavity with respect to various geometrical parameters will lead to different amplification patterns in the center and edge of the canyon. One of the most important results is the increase in amplification of long periods compared with the case of a canyon without cavity. Moreover, parametric research shows the fact that the cavity detail and canyon height, the ratio of cavity to the canyon size and cavity location impact on the seismic amplification of the canyon surface. Finally, spectral amplification coefficients of the canyon surface led by the cavity are reported for different cases of the canyon-cavity interaction.

A numerical study on effect of underground cavities on seismic ground response due to Rayleigh wave propagation

“…They confirmed that cavities significantly influenced ground motion at high frequencies. In this context, many researchers have explored the cavity or tunnel effect on seismic ground response under body waves through various methods, such as analytical methods [8][9][10], numerical simulations [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26], and model tests [27][28][29][30]. Due to the complexity involved in wave propagation and limitations in modeling complicated systems of equations, numerical techniques are more effective compared to analytical and model tests for the parametric study of ground vibration problems [31].…”

Numerical study on the influence of near-fault and far-fault earthquakes on a subway station with emphasis to scattering on the wave propagation

“…They showed that a significant amplification and a horizontal peak ground acceleration appears at the edge of the larger subway station and in the vicinity of the Daikai station, respectively. Other researchers [11], [12], [13], [14], [15] used the boundary element method to study the ground surface displacement and dynamic behaviour of the underground structures. They concluded that the presence of underground cavities had a noteworthy effect on the amplification generated on the ground surface.…”

Scattering of harmonic P1 and SV waves by a shallow lined circular tunnel in a poroelastic half-plane

“…In order to simulate the scattering of waves in an elastic half-plane by the inclusions, a lot of literatures have been devoted in the latest decades by either analytical or numerical schemes. In the numerical solutions, the boundary element method (BEM) is widely used for the scattering of stress waves since the far-field radiation condition can be automatically satisfied [4][5][6][7][8][9][10][11][12][13][14][15].…”