Boundary element modeling of elastic waves propagating in the media with randomly distributed cracks

The problem about scattering of elastic waves by cracks or inclusions is important especially in seismology and geophysics.Numerical modeling of seismic data has long been recognized to be a powerful interpretive tool for understanding the complicated wave propagation.In this paper,a 2D BEM program was used to model seismic waves excited by a point explosive source propagating in the media with randomly distributed cracks.The accuracy of the method was well checked by means of computing waves propagating in the medium without any cracks with the corresponding theoretical solution.It was shown by the first example that different spatial distributions of the same scatters led to different wavefield characteristics.The effects of aspect ration of cracks with the same spatial distribution was shown in the second example.It was concluded that a lot of energy was trapped in areas with crack clustering.When the size of the clusters were small,most of the energy would propagate through the whole model,and high clustering would result in more attenuation when waves passed through the areas.With increasing of the aspect ration of cracks,the attenuation increased but some local energy might be concentrated.