Soil Seepage Force Loading Method Implementation And Application Research

In the field of geotechnical engineering, the water in soil has a great impact on the mechanical properties of soil structure, the problems of seepage force which produced by the water pressure in soil is a significant issue in the field of geotechnical engineering. During the solving of seepage force problem, the method of traditional analytical for solving complex boundary conditions of seepage force field is a very difficult, and the method of experiment spend a long time and much money, and just do scale experiments generally. In recent years, the numerical simulation method is widely used in solving soil seepage problems.ABAQUS finite element analysis software due to its strong nonlinear solution capability has a wide range of applications in geotechnical engineering, the software can simulate the saturated – unsaturated soil, steady- unsteady seepage problem and soil consolidation deformation problem, but there is not enough in dealing with the problem of seepage force. By using the software subroutine secondary development function, ABAQUS can be implemented in the seepage force loading of the soil structure.In this paper, in order to solve seepage force load problem in practical engineering, On the basis of seepage force basic theory, compose the statement of URDFIL ABAQUS subroutine, in order to achieve converting the pore pressure values of grid in each network element to average seepage force value of each network element obtained from seepage analysis. The basic seepage concept [1] is the forces along the soil particles per unit volume in the direction path, in the horizontal direction, the seepage force is the pore water pressure gradient value in the horizontal direction, in the direction of gravity, the seepage force is not only the pore water pressure gradient value in the gravity direction, but also considered the offset of pore water gravity of unit volume. After getting the horizontal and vertical seepage force value of network element, The seepage force value is loaded in the corresponding mechanical model element by DLOAD subroutine, achieve seepage force loading.Build a simple one-dimensional seepage model, based on the results of the mechanical deformation after seepage force is loaded, prove the value of this loading method is same with the theoretical value; and then build another simple two-dimensional seepage model, compare the impact of calculation results of different loading method, prove that the results obtained in larger displacement and more uneven distribution of stress when using surface load instead of seepage force; Finally, apply this method to numerical analysis of cofferdam precipitation process of a lake channel, and then analyzed seepage force field and mechanical deformation results, summarized the general rule of seepage force distribution of precipitation, and further demonstrate the effectiveness and accuracy of the seepage force loading method presented in this paper.