Elastic Wave Scattering Around 3-D Cavity In Half-Space

In recent years,the safety issues of cavity itself and the structures of projects nearby have received widespread attention under the circumstance of seismic excitation,engineering blasting and other extrinsic factor,etc.According to engineering wave propagation theory,the impact of seismic excitation and engineering blasting on underground cavity is essentially an interact between elastic waves(natural seismic waves,blasting vibration wave)and cavity,which can be attributed to the dynamic response of underground cavity,therefore,it is significant to research the issues of the dynamic response of underground cavity under the action of elastic waves.The scattering of incident plane waves by three-dimensional(3-D)cavity in elastic half-space is investigated by using an indirect boundary integral equation method(IBIEM)and by using the dynamic Green's functions for concentrated force source.It is shown that,the dynamic responses around 2-D and 3-D cavity are evident differences,and the surface displacement peak of 2-D cavity is larger than that of 3-D cavity,with more complex space distribution and more intense peaks in 2-D case,while the stress peak of 3-D cavity is greater than that of 2-D cavity,with evidently different peak location,and such difference becomes larger with the frequency increasing.The scattering of incident spherical P waves by 3-D cavity in elastic half-space,the scattering of incident spherical P waves by 3-D cavity in elastic layered half-space and the scattering of incident spherical P1 waves by 3-D cavity in poroelastic half-space are investigated by IBIEM and by the dynamic Green's functions for concentrated force source,spherical dilatational source and pore pressure.It is shown that,the dynamic response around 3-D cavity is significantly affected by the curvature of incident spherical P waves;Due to the self-vibration features of site,the dynamic responses around 3-D cavity in layered and in homogeneous half-space are distinct differences;the dynamic responses around 3-D cavity in poroelastic and in elastic half-space are evident differences.