Continuous Injected Group Curtain of Dam

Finite element method is used to analyze and model grouting to confirm the extent of grouting in terms of treatment zone and degree of improvement of ground properties required. Injection as a miscible phase procedure is defined as the grouting of fluidized materials into voids of the saturated ground or spaces between ground and adjacent structure, generally through bore holes and under pressure. For many engineers, injection is still considered an art rather than a science. Therefore, its successful application requires a great deal of experience, thorough knowledge of geological conditions, and an awareness of equipment capabilities and limitations. The basic phenomenon of grout propagation is tried to be described as a continuous fluid- displacement in deformable saturated porous media. The solution of mathematical formulation results in a highly coupled and non-linear system requiring specific numerical techniques. The pressure – displacement formulation is discretized in porous media by application of the weighted residual method. The whole system is then integrated in time by means of a simple three level scheme for nonlinear variation of parameters. This paper describes a new approach to modeling injecting domain based on a nonlinear Darcian flow and theory of consolidation. The proposed model utilizes the variation of the coefficient of permeability with respect to the pore fluid pressure based on a nonlinear Darcian flow characteristic below certain hydraulic gradients and void volume changes. The potential of the proposed model is evaluated in predicting the propagation of grouting material due to a single injection bore hole. The general comparison indicates that this approach is capable of solving injection boundary value problem.

کلیدواژه ها:

grout propagation ، nonlinear Darcian flow ، three level scheme ، hydrodynamic permeability