Excavation Displacement Analysis By Distinct Element Method In Three Gorges Project

Where a rock slope comprises multiple joint sets, which control the mechanism of failure, continuum modeling is not so best suited for the displacement analysis of slopes. A discontinuum modeling approach may be considered more appropriate, because it not only can token the nonuniformity and heterogeneity of the geo-materials, but also be good at modeling the generation and movement of the fragments. Based on particle element model, a lattice solid model used in distinct element method is established and applied to rock slope stability analysis in three gorges project in this paper.The main research focuses are as followed:(1) Based on particle element model, a lattice solid model (LSM) used in distinct element method is proposed. In the Lattice solid model, the elements are distinct and detected by collision detection method. The neighbor elements are connected by the beams, which help to establish a net of beams. Through the strength criterion, the existence of the beam is detected. Matrix Displacement Method is used to solve the force applied to the beams, and the movements of the particles are described by the distinct element method.(2)A C program called DEM_LSM2D is developed, in which the Lattice Solid Model is adopted. The pre-process and post-process of the DEM_LSM2D is programmed by C and OpenGL function library. The interface and the of function extension module is finished by VB6.(3)The deformation of high slope in the Three Gorges project is simulated by the DEM_LSM2D. Taking excavation into consideration, the displacements on the horizontal and vertical are calculated. Comparing the field data and the modeling result, it shows that the Lattice solid model method is a proper way to model the rock deformation under unloading conditions.