A 2D/3D method of the groundwater flow and stability analysis of a slope with dewatering wells

This paper presents an approximate method for a groundwater flow analysis in the case of a slope with vertical dewatering wells distributed equidistantly. Firstly, a multi-scale problem of flow to a drainage well is solved and flow model to a perforated tube with a filter screen is shown. Secondly, a method of building quasi-3D flow model of a slope with vertical dewatering wells using a technique of overlapped 2D mesh is shown. A short description of the implementation of this 2D/3D flow model for the ZSoil.PC code is given. The results of the described 2D/3D method are compared with a referential 3D analysis giving an acceptable level of agreement. Finally, the 2D/3D method of flow analysis is used in a two-phase (flow + deformation) formulation of a slope stability problem. The comparison of the results of these analyses with fully 3D (referential) analysis, on an example problem provides a very close accurate stability and deformation estimation; however, the computational time used for the 2D/3D analysis is significantly shorter than required by 3D analysis.