Improved Analytical Solution for Air–Boosted Vacuum Consolidation of Saturated Soil Using Eigenfunction Expansion Method

Abstract

Soft foundation consolidation engineering applications and experimental studies have proven the effectiveness of the air–boosted vacuum preloading method (AVP). The sand well consolidation theory, a typical axisymmetric consolidation, is adapted to analyze the whole consolidation process of the saturated soil by air–boosted vacuum preloading. The present analytical solution for air–boosted vacuum consolidation of the saturated soil is more suitable for application in a deep soft foundation. With the solving method, the general solution through separation of variables is used, which is mathematically used for the homogeneous partial differential equations. However, the partial differential equations for solving the consolidation of the AVP method are nonhomogeneous. Therefore, the eigenfunction expansion method for nonhomogeneous equations is proposed and validated in this study. Results showed that the improved analytical solution by the eigenfunction expansion method is more consistent with the numerical solution than that of the previous method using the general solution by separation of variables, which leads to a lower error ratio of less than 2%. The improved analytical solution can be used to predict the consolidation of deep foundations by air–boosted vacuum preloading effectively.

Analysis of Consolidation by Vertical Drain with Vacuum Preloading Based on Axisymmetric Biot’s Consolidation Theory

“…Vacuum preloading is a widely used technique to accelerate the consolidation rate of foundations. Extensive research has been conducted on vertical drain well consolidation theory to predict the consolidation process of foundations during vacuum preloading, resulting in significant achievements, which is a typical axisymmetric problem in soil mechanics [1]. Barron proposed two assumptions, namely free strain consolidation and equal strain consolidation, based on the different strain forms of vertical drain well consolidation [2].…”