Computational instability of sedimentation-consolidation model based on an interaction coefficient

Abstract

Serious computational instability problems are usually encountered in solving the sedimentation-consolidation model based on an interaction coefficient (SCMIC). In this study, the computational instability behavior of SCMIC is investigated with given upwind finite difference scheme. Results show that significant numerical errors occur when low grid density is used. By analyzing the variations of governing equation coefficients with time, it is found that the computational instability is due to the highly nonlinear variation of d σ ′ d e with e ( σ ′ is effective stress and e is void ratio), which causes significant errors in calculating the average value of d σ ′ d e . By eliminating the effect of the high nonlinearity of d σ ′ d e , the computational instability of SCMIC can be completely resolved. Such a resolution method for the computational instability overcomes the restriction of grid density, which can facilitate the simulation of simultaneous sedimentation and consolidation in the geotechnical engineering field.