An explicit finite difference method for analyzing hazardous rock mass

[摘要] ENGLISH ABSTRACT: FLAC3D is a three-dimensional explicitnite difference program for solving a variety ofsolid mechanics problems, both linear and non-linear. The development of the algorithmand its initial implementation were performed by Itasca Consulting Group Inc. The mainidea of the algorithm is to discritise the domain of interest into a Lagrangian grid whereeach cell represents an element of the material. Each cell can then deform according to aprescribed stress/strain law together with the equations of motion. An in-depth study ofthe algorithm was performed and implemented in Java. During the implementation, it wasobserved that the type of boundary conditions typically used has a major in uence on theaccuracy of the results, especially when boundaries are close to regions with large stressvariations, such as in mining excavations. To improve the accuracy of the algorithm, anew type of boundary condition was developed where the FLAC3D domain is embeddedin a linear elastic material, named the Boundary Node Shell (BNS). Using the BNSshows a signi cant improvement in results close to excavations. The FLAC algorithm isalso quite amendable to paralellization and a multi-threaded version that makes use of multiple Central Processing Unit (CPU) cores was developed to optimize the speed of thealgorithm. Thenal outcome is new non-commercial Java source code (JFLAC) whichincludes the Boundary Node Shell (BNS) and shared memory parallelism over and abovethe basic FLAC3D algorithm.

[发布机构] Stellenbosch University