Large strain consolidation of sand-drained ground considering the well resistance and the variation of radial permeability coefficient

Abstract

Based on Barron’s equal strain consolidation theory of sand-drained ground and Gibson’s one-dimensional large strain consolidation theory, and considering the well resistance of drains, the variation of radial permeability coefficient and the vertical flow, a more general governing equation of large strain consolidation of sand-drained ground is established and solved by using the finite difference method. The correctness of the numerical solution is verified by comparing with the existing consolidation model and small- strain analytical solution. Using the numerical solution, the large strain consolidation behaviors of sand-drained ground are investigated. The analyses show that the well resistance of drains can reduce the consolidation rate of sand-drained ground. But when the permeability coefficient of drains increases to a certain value, the well resistance of drains can be ignored. The variation pattern of radial permeability coefficient has a great influence on the consolidation rate of sand-drained ground. The consolidation rate is faster under the parabolic pattern than that the linear pattern. The vertical flow accelerates the consolidation rate of sand-drained ground, when the radius ratio is small, and the influence of the vertical flow on the consolidation rate should be considered. The larger the ratio of compression index to permeability index is, the slower the consolidation rate of sand-drained ground will be.

Keywords

• sand-drained ground
• large strain consolidation
• well resistance
• radial permeability coefficient
• vertical flow
• finite difference method