Consolidation theory of single-layer homogeneous soil under combined vacuum and radial loading

The air-boosted vacuum preloading method utilizes a booster pipe positioned between the vertical drain and the vacuum pipe to apply radial loads to the soil. The application of these loads significantly increases the pressure difference around the drainage system, which not only accelerates consolidation but also reduces clogging in vertical drains. This paper, considering air-boosted vacuum and radial loading, develops a foundation calculation model for the consolidation of single-layer homogeneous soil. The consolidation process is segmented into three distinct stages: vacuum preloading, radial pressurization, and vacuum consolidation. It accounts for equal strain, boundary, and initial conditions, employing the separation of variables method. An analytical solution for the radial average consolidation degree in single-layer homogeneous soil foundations under air-boosted vacuum and radial loading is derived. Calculations reveal that smaller well diameter ratios and higher horizontal permeability coefficients enhance the effectiveness of foundation reinforcement under these conditions. Laboratory experiments were conducted by using a self -developed soft soil model test system for air-boosted vacuum and radial loading. The comparison of theoretical and experimental values of radial average consolidation degree confirms the analytical solution accuracy. These findings contribute to the advancement of combined vacuum and radial loading theory, fostering future research in this field.