Executive Summary : | The development of Terzaghi's classical one-dimensional consolidation theory has led to extensive research on consolidation in saturated fine-grained soils. However, in construction sites, particularly in arid and semi-arid zones, the consolidating layer remains partially saturated. This necessitates analyzing transient flow-induced volumetric deformations in problematic soils, such as expansive and collapsible soils, using unsaturated soil mechanics. Unlike saturated soils, the behavior of the vadose zone is governed by two independent stress state variables: net normal stress and matric suction. The application of additional external load in an undrained condition is not sustained by generated excess pore pressures alone; instead, it results in volumetric deformation due to air compression and dissolution.
This project aims to conduct a detailed investigation of unsaturated soil consolidation, considering stress deformation and pore fluid dissipation simultaneously. The project will conduct numerical experiments varying load type, flow type, drainage boundaries, hydro-mechanical properties of the consolidating layer, excess pore air and water pressure distributions, soil water characteristics curve, hydraulic conductivity functions, and stress dependency on permeability and compressibility characteristics. The project will also incorporate the rheological properties of unsaturated clays, using fractional-derivative viscoelastic models for long-term deformation and other rheological characteristics. The analysis will address one- and two-dimensional problems using finite element and finite difference techniques, adding a new dimension to the overall study of consolidation. |