  An efficient and easy-to-implement method is proposed to regularize integral
equations in the 3D boundary element method (BEM). The method takes advantage
of an assumed three-noded triangle discretization of the boundary surfaces. The
method is based on the derivation of analytical expressions of singular
integrals. To demonstrate the accuracy of the method, three elastodynamic
problems are numerically worked out in the frequency domain: a cavity under
harmonic pressure, diffraction of a plane wave by a spherical cavity, and
amplification of seismic waves in a semispherical alluvial basin (the second
one is also investigated in the time domain). The numerical results are
compared to semi-analytical solutions; a close agreement is found for all
problems, showing the accuracy of the proposed method.
