A boundary element method for analysis of contaminant transport in fractured and non-fractured porous media

This paper presents a boundary element method for modelling contaminant tra nsport of a contaminant species in porous media which consists of both frac tured and non-fractured material. In the fractured material, blocks of soli d matrix comprising the parent soil material are assumed to be separated by discontinuities in the form of fissures, fractures or joints. The method d eveloped in this paper utilises a double porosity model to deal with contam inant transport in the presence of the discontinuities and solid blocks. Th e underlying assumption of a double porosity model is that the solid matrix blocks, said to have the primary porosity, constitute one continuum while the network of discontinuities, the secondary porosity, form the other cont inuum. Flux transfer between the two interacting continua is represented by a source/sink term in the governing equation. When there are no discontinu ities, the material reduces to a single continuum with one porosity and so the formulation is able to deal with deposits which consist of both fissure d and non-fissured material. This approach is used to develop a boundary el ement technique which can enable a wide range of problems of practical inte rest to be analysed. (C) 1998 Elsevier Science Ltd.. All rights reserved.