Abstract:

In order to overcome the difficulty in the finite-element analysis of urban seepage field , a newly-devised singular point-substructure method is put forward to simplify the modeling of underground structures in the urban seepage field. In this method , first , the seepage field is meshed with sparse elements. Next , the elements sharing a singular point of an underground structure are extracted out as substructures. The extracted substructures are then refined layer by layer with similar elements. The equivalent stiffness matrixes and nodal vectors of the substructures are finally calculated via the static concentration from the inside to the outside layer by layer. Analytical results show that the proposed method can avoid the meshing of small-size structures in a large-scale region , and that it is of the same efficiency and accuracy as the infinite similar element method. Moreover , the proposed method is more convenient for the treatment of infiltration , phreatic water , multiple permeable layers and suspended underground structure.

Key words: urban groundwater, seepage, substructure, singular point, infinite similar element method