One-dimensional Consolidation Theory Modified By Hyperbola Model Under Generalized Time-depending Loading

Since the consolidation theory has been proposed by Terzaghi from 1924, it plays an important role in solving the problems of controlling and forecasting the distortion of soft soil foundation. The proposals of the consolidation theory and the effective stress principle symbolized the birth of the soil mechanics, from which we can know the importance of the consolidation theory. But the Terzaghi's consolidation theory is based on a series of supposes, which are far different from the real conditions. Therefore, we need to modify the Terzaghi's consolidation theory. We need to remove the limitations of supposes and make this theory close to the real condition gradually to make the computing results close to the observed values. In recent years, as the fast development of the technique of the computer, the consolidation theory develops quickly. This article mainly concentrate on modifying this theory and analyzing the consolidation character. The prime tasks and the achievements in this article are as follows:(1) Suppose the relationship between the void ratio and the effective stress to satisfy the hyperbola model. With the assumption that the decrease of the hydraulic conductivity is proportional to the decrease of the compression conductivity, the one-dimensional nonlinear partial differential consolidation equation which is under the generalized time-depending loading is deduced. With a transform, the nonlinear partial differential equation is changed into a linear one. According to the idiographic initial condition and the boundary condition, the equation is then solved by using the variable separation method;(2) Have analyzed some model loading forms which are frequently used in the consolidation computation, and pointed out two kinds of familiar loading forms - time-depending loading and low-frequency cyclic loading. Based on the consolidation values under the generalized time-depending loading, the consolidation values that are under the time-depending loading and the low-frequency cyclic loading have been deduced. The consolidation values which are under the common time-depending loading that is one kind of time-depending loading has been deduced too;(3) Based on the consolidation values of the common time-depending loading and the low-frequency cyclic loading, the relevant computer programs have been developed by using FORTRAN language. In order to make these programs easy to be known, a brief explanation and a chart were shown. Otherwise, in order to compare with the theory which is modified by e-1gp model, a FORTRAN computer program which is based on the consolidation values that are modified by e-lgp model is developed;(4) Making use of the experimental parameters that are from a highway soil and the computer programs, I have analyzed the consolidation characters that were under the common time-depending loading and the low-frequency cyclic loading, analyzed the influence that every factor influence the consolidation characters, and drawn the charts using the computing results. (5) Making use of the soil experimental parameters and the computing programs, I have compared the two constitutive models when they are used to modify the consolidation theory from several aspects. The resuluts show that the hyperbola model is better to reflect the influence of constitutive relationship to consolidation than e-lgp model.