Analytical and numerical solutions for vacuum preloading considering a radius related strain distribution

A system of PVDs combined with other preloading methods such as vacuum preloading and surcharge preloading is an effective and economical method which is widely used in the ground treatment. The consolidation theories for drain wells under equal strain condition are often used in the design of ground treatment by PVDs. A radius related strain distribution is proposed to get analytical solutions for the excess pore water pressure and settlement. A linear distributed vacuum pressure along the drain depth and the smear zone as well as well resistance are considered. The numerical results for vacuum loading process are obtained by developed FEM model to compare with the analytical solutions. The results indicate that the influence of the equal strain hypothesis cannot be neglected when n is larger than 10, where n denotes the ratio of diameter of the model to diameter of the drain. The analytical solutions proposed in this paper are more consistent with the numerical results than the analytical results obtained employing the equal strain condition.

► A radius related strain distribution is proposed and incorporated in the analytical model for vacuum preloading with a central PVD. ► The numerical model without assumption of strain distribution pattern is developed to adequately describe the vacuum preloading process. ► The proposed analytical solution is more consistent with the numerical result than the analytical result obtained under the equal strain condition by previous researchers.