Rongkai Zeng , Shuying Wang , Yang Zhang , Tongming Qu
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引用次数: 0
Abstract
Soil conditioning with foam agents can reduce the permeability of virgin soils and mitigate the risk of uncontrollable mud gushing during the excavation of Earth Pressure Balanced (EPB) shield machines. This study employs a combined Computational Fluid Dynamics (CFD) − Discrete Element Method model (DEM) method to simulate the seepage process in foam-conditioned excavated soil. Through discovering migration patterns of foam particles and their effects on macroscopic permeability under various hydraulic gradients, this study unveils the micro-mechanisms governing the permeability of foam-modified soil. Results indicate the feasibility of using hydraulic gradient amplification to examine foam particle migration channels and permeability changes. Furthermore, the findings show that the initial stabilization period in the seepage experiment arises from a dynamic equilibrium between the inflow and outflow of foam in the lower layers. In the upper and middle soil layers, foam migration paths show resilience to water pressure during the initial stage of seepage, but become increasingly responsive to the pressure when migration is hindered. The migration paths of the foam particles in the lower layers remain consistent across different water pressures. The migration speed of individual foam particles is determined by both water pressure and pore structure, while the overall migration speed of the foam increases as water pressure rises.
期刊介绍:
The use of computers is firmly established in geotechnical engineering and continues to grow rapidly in both engineering practice and academe. The development of advanced numerical techniques and constitutive modeling, in conjunction with rapid developments in computer hardware, enables problems to be tackled that were unthinkable even a few years ago. Computers and Geotechnics provides an up-to-date reference for engineers and researchers engaged in computer aided analysis and research in geotechnical engineering. The journal is intended for an expeditious dissemination of advanced computer applications across a broad range of geotechnical topics. Contributions on advances in numerical algorithms, computer implementation of new constitutive models and probabilistic methods are especially encouraged.