New Study On Statistical Damage Theory For The Simulation Of Deformation Process Of Geo-material

The simulation of the deformation process of geo-material in hard-working status or in soft-working status, is the emphasis of the research of the mechanics of geo-material. The development of statistical damage theory provides an effective idea and approach for it. But there are some defects in the damage constitutive models of geo-material based on this theory, it can't reflect the strain softening-hardening deformation process of geo-material under complicated stress and the characteristic of volume change in the stress-strain process of geo-material, furthermore, physical meaning of the model's parameters isn't definite. To improve the research of the simulation of the deformation process of geo-material, further investigated is needed. For these, study was developed in this paper to solve the problems, which is of great thoeratical and practical significant.The means of the simulation for the strain softening and hardening deformation process of rock and saturated soil is the major content. Firstly, on the base of the research of the rock's damage model which considers the bearing capacity of rock after its yielding or failure, according to the law that micro-unit strength of rock accorded with normal distribution, and statistical damage theory, the damage model and the statistical damage constitutive model which can simulate the deformation process of rock are set up. By studying the characteristic of the softening and hardening process of rock and discussing the relationship between the model's parameters and the characteristic of the stress-strain full curve for rock such as the stress and strain at the peak-stress point, the way for determining the parameters of the rock's constitutive model is set up. The model's parameters indicate physical meaning, which is easy to determinate and suitable for complicated stress. Secondly, based on the rock's damage model, combined with the effective stress theory, the damage model that reflects the damage mechanics of saturated soil is established. On the base of the statistical damage theory and volume deformation modulus, the corresponding statistical damage constitutive models of saturated soil are built in accordance with three different test conditions for saturated soil, which can describe the effect of the volume compress under the deformation process of saturated soil. Thirdly, the rationality about the constitutive models of geo-material have been shown in comparison with the results of the tri-axial tests of saturated soil and the existing curve of tri-axial tests of rock.Compared with the existing similar results, the research in the text obviously has superiority, which completes the method of simulation on the strain softening and hardening process of geo-material.