Wave propagation and localization problems in saturated viscoplastic geomaterials

This paper presents an improved algorithm to deal with wave propagation and localization problems in saturated viscoplastic geomaterials. It consists of a mixed formulation in terms of effective stress, velocity and pore pressure that uses a fractional step algorithm allowing the use of equal order of interpolation for the three variables and the simplest element such as the linear triangle. The viscoplastic model used is of modified cam-clay type. Viscoplasticity results in a strong source term that deteriorates the accuracy of the two-step Taylor–Galerkin algorithm. Therefore a Runge–Kutta splitting scheme has been used to deal with the source terms, resulting in a better accuracy of the method. Copyright 2006 John Wiley & Sons, Ltd