Test Research On Damage Statistic Constitutive Model Of Unsaturated Soil Using WF Triaxial Apparatus

As a special soil, the mechanical characteristics and constitutive model of unsaturated loess are the central part of research topics. Unsaturated soil exist in an unsaturated state, this is particularly true in tropical and arid regions. Generally this condition will have occurred in a very dry environment where the amount of evaporation from the ground surface exceeds the amount of rainfall. So the sample consists of air, water and solid , which mechanical characteristics to be understand will guiding engineering in unsaturated loess area.In this thesis, the mechanics behavior and deformation characteristic is described to have series of laboratory test of the unsaturated loess of lanzhou area using Wykeham Farrance triaxial apparatus. Then, the matric suction curve with time is analysised, and more, the effect of water content on matric suction is described.Secondly, based on the state of the art in the constitutive relation for unsaturated soils, another important achievement of this thesis is that a new damage statistic constitutive model of unsaturated soil is deduced, which based on the assume that the sample submit to continuity and homogeneity, as well as microcosmic strength submit to normal distribution. Further more, using the result of stress—strain and Duncan—Chang model, two parameters of damage statistic constitutive model are calculated. It was found out that relational curves which calculate the parameters were almost consistent with liner well.Finally, the relevant research aiming at the damage statistic constitutive model of unsaturated loess had been looked forward.