Theoretical And Experimental Studies On Rheological Consolidation Of Soft Soil

It is well known that rheological property is one of the important properties of soft soil. After the development of more than 60 years, the rheological consolidation theory have been greatly enhanced. However, about the further improvement of rheological consolidation theory, and rheological model of soft soil, as well as the determination of its parameters, etc., there are still many to be done. In order to make rheological consolidation theory more perfect, and find a feasible way for determining rheological parameters, as well as to promote the practical application of rheological consolidation theory, rheological consolidation of soft soil is studied carefully and in-depth from theoretically and experimental aspects in this dissertation. The main original work includes:1. Based on the linear rheological model of four units, analytical solutions are obtained and summarized for one-dimensional consolidation of soft soil under several types of time dependent loading, and the rheological consolidation behavior of soft soil is analyzed. It is indicated that the variations of both loading type and parameters of rheological model have great influence on the consolidation process.2. Based on the linear rheological model of three units, the analytical solution for one-dimensional consolidation of soft soil with two impeded boundaries under conventional cyclic loading is developed using integral method. The relevant rheological consolidation behavior of soil is investigated by using the solution and the different influences of impeded boundaries and rheological parameters on the consolidation are discussed3. GDS Advanced Consolidation Test System and the corresponding experimental steps are introduced in detail, and a variety sets of rheological consolidation tests with Xiao-shan soft soil are conducted on the test system. Many testing curves, including the ones for pore water pressure dissipation, are prepared to discover the behavior of rheological consoiidation of Xiao-shan sof soil. It is indicated that rheological characteristic of Xiao-shan soft soil is remarkable, and the over-consolidated ratio affects the coefficient of secondary consolidation significantly.4. A new convenient nonlinear curve fitting method with high accuracy is developed for determining rheological parameters from teat data. By using this method, the testing results ofXiao-shan soft soil is analyzed, and parameters of rheological model of three units and of four units are respectively obtained and the variation law of these parameters investigated. Comparisons are then made between the results obtained by the developed analytical consolidation theory using these parameters and the ones obtained directly from test.5. The parameters of non-linear rheological consolidation model are obtained for Xiao-shan soft soil based on the test data. Using these parameters, theoretical settlement and pore water pressure are obtained by using available semi-analytical method for nonlinear rheological consolidation analysis and compared with the ones from tests. It is shown that theoretical results are in fairly good agreements with that of tests, and that comparing to liner rheological model, non-linear rheological model is more suitable to Xiao-shan soft soil...