Abstract:

The effect of stress states on the earth's surface deformation is investigated. With clay selected as test sample, deformation rules obtained by a series of classical triaxial compression test under different stress paths. Based on the tests, a numerical constitutive model under different stress paths is derived by numerical modeling method. Moreover, the constitutive model is set in FEA program to simulate earth's surface deformation under different stress paths. By comparison of the cases, some conclusions are drawn as follows: ①effects on the earth's surface deformation under different stress paths are different; ②the influences of stress paths should not be neglected in analysis of the earth's surface deformation; ③the constitutive model by numerical modeling method which can reflect the effects of stress paths by using different weights fits for analysis of the earth's surface deformation; ④the maximum volumetric strain of path TC is about 20% lower than path CTC; ⑤Shearing dilatancy field of CTE path is larger than that of CTC path while shearing contraction field is smaller. Maximum relative difference of dilatancy volumetric strain between the two paths is about 17.3% whereas maximum relative difference of contraction volumetric strain is about 98%.

Key words: earths surface deformation, stress path, constitutive model, numerical simulation, dilatancy, contraction