ABSTRACT
MPM is very well suited for dealing with finite strains and large displacements that are developed when collapse or near collapse problems such dam failures are studied.
2 MPM SIMULATION A DAM FAILURE
Here the simulation of Aznalcollar dam failure is presented. Aznalcóllar dam, a 27 m high homogeneous rockfill structure failed catastrophically on April 25th 1998. The dam helped to create a large tailings pond of finely crushed pyritic granular
1 INTRODUCTION
The Material Point Method (Sulsky et al., 1994, Sulsky and Schreyer, 1996) represents the material contained in a region as a collection of unconnected particles. A mass is assigned to each particle which remains fixed during all the calculation process, thus assuring mass conservation. Other initial values, such as velocities, strains and stresses, are also assigned to the material points. The discrete motion equations are not solved at the material points. Instead a support mesh, built to cover the full domain of the problem, is used (Figure 1). The variables required to solve the motion equations in the mesh at any step of the analysis are transferred from the particles to the nodes of the mesh by using mapping functions. These are typical shape functions used in the finite element method. Boundary conditions are imposed at the mesh nodes and the motion equations are solved by using an incremental scheme. Then the quantities carried by the material points are updated through the interpolation of the mesh results, using the same shape functions. The information associated with the mesh is not required for the next step of the analysis; therefore it can be discarded provided that the boundary conditions that may have been established are preserved.
