Abstract:

Duncan-Chang model assumes the stress-strain relation of soils to be hyperbolical and presumes that the relationships between some parameters and ambient pressure are fixed, which not only goes against the fact of varied feature of soils but also can’t make the results of model agree with those of test perfectly. Based on analysis of test. with the development of computer, a lot of software is produced, which can fitting curves. So the parameters are able to be got by pilot calculation and the optimum functional relationships between some parameters and ambient pressure also are able to be hunted through these software. This method is different to that of Duncan-Chang model. On the basis of Duncan-Chang model, the negative-power model is established for soils; it’s able to display variety of the stress-strain curve of soils using a changeable parameter; and its parameters are determined in the previously mentioned way. The equation of tangent modulus is deduced based on the new method. The negative-power model can better meet test in comparison with Duncan-Chang model.

Key words: negative-power model, Duncan-Chang model, parameter, tangent modulus