Implementation and application of ABAQUS-PFC3D coupling program framework based on CFD-DEM fluid-solid coupling model: indoor test scale and engineering scale

In this study, an ABAQUS-PFC3D coupling program framework based on the Computational Fluid Dynamics (CFD)-Discrete Element Method (DEM) coupled fluid-solid analysis method is constructed, which can be run in Windows computer system and Python language environment, and takes into account the high efficiency, simplicity, and computational stability of the bi-directional interaction of fluid-solid field information. The coupled program framework is validated using a classical particle-fluid coupling model case to assess its stability and accuracy. Further, the ABAQUS-PFC3D coupling program is used to study the evolution characteristics of internal erosion of gap-graded soil-rock mixtures of different fines contents (indoor test scale) and reproduce the whole process of water and mud-surge disaster in the Yonglian water-rich fault tunnel in Jiangxi, China, including the disaster-causing stages of palm collapse, accumulation of broken rock inside the tunnel, collapse within the fault, and surface collapse (engineering scale). The results show the stability of the coupling program framework, which improves a good reference for the popularization and application of the CFD-DEM fluid-solid coupling model.