Simplified Consolidation Theory For Unsaturated Soils And Its Application In Civil Engineering

The most part of the plant’s soil is unsaturated soils. Many countries have been or are being subjected to unsaturated soil’s harm, and suffered huge losses. The consolidation theory for unsaturated soils problem is the importance study contents in geo-technical engineering. Many engineering problems are related with the consolidation for unsaturated soils. Considering the theory problem and engineering appliance, it is very significant for us to make a systematic study.The interaction equations between unsaturated soil’s deformation、pore water and air has been derived by the foreign and domestic scholars, and the theory of unsaturated soil mechanics has been builded in the early nineteen ninties. The interaction equation including five basic variables、three displacement components、pore water pressure and pore air pressure. In addition, a plurality of intermediate variables and formula also used in establishing control equations. Although many scholars put forward the corresponding equations and formulas, but solving this multi variable equations is very complex. So far, there is no universally accepted the consolidation for unsaturated soil theory, and have not yet entered the practical stage.In order to make the consolidation theory for unsaturated soils can be applied to civil engineering, this thesis which based on summarizing the predecessor’s research results mostly covers the unsaturated seepage theory and coupling between seepage field and stress field of the unsaturated soils; The simplified consolidation theory for unsaturated soils and the equation of simplified consolidation theory for unsaturated soils; Simplified consolidation for unsaturated soils finite element equations and numerical simulation programming.1.This thesis first expatiate upon moisture potential theory, then study and discuss the basic unsaturated seepage theory, the relation of soil-water’s characteristic curve and seepage coefficient.2.Based on the Darcy law and conservation of mass, this thesis have deduced differential equations of considering changing the saturation of soil skeleton stress field and seepage field and discussed its interaction coupling mechanism.3.From Biot consolidation theory, assuming a constant rate of soil exhaust, this thesis pushed to a simplified theory of unsaturated soil consolidation and simplified consolidation equations.4.Using FEPG automatically generated finite element software programming finite element program, simulation analysis and applications for the practical problems of simplified consolidation theory for unsaturated soils.5. Summarized and analyzed the results. The results are reasonable. The results for the consolidation theory of unsaturated soils play a practical role in promoting.