固结与流变特性及其参数取值研究是软基上结构物长期沉降课题的重要组成部分。针对宁波轨道交通工程的两个典型土层,开展了基于GDS固结仪的流变固结试验,获得了土样的主固结与次固结性状参数。采用Gibson三元件流变模型结合Matlab软件的拟合功能,得到了土样的三元件流变模型参数。通过对试验结果进行分析总结,发现宁波软土的次固结过程表现出较明显的非线性。次固结系数Ca与压缩指数Cc近似符合Ca/Cc=0.02±0.01。宁波软土的一维流变过程符合Gibson三元件流变模型规律,且其模量参数和黏滞系数均随固结压力的增大而增大。
Consolidation and rheological properties of soft soil and their values are important parts of the researches of long-term settlement of structures on soft ground. A series of rheological consolidation tests for two typical soil samples in the Ningbo Rail Transit project are carried out based on the advance GDS consolidation test system. Parameters of the primary consolidation and secondary consolidation behaviour of soft soil are obtained based on the test. On the basis of the introduction of a three components rheological model( Gibson model),the model parameters for the three components rheological model are obtained by using the Matlab fitting method. The results indicate that the secondary consolidation behaviour of the Ningbo soft soils exhibit obvious nonlinear properties; the secondary consolidation coefficient is approximately in linear relation to the compression index and there is Ca/Cc= 0. 02 ± 0. 01; the one-dimensional rheological consolidation behavior for the Ningbo soft soil agrees with the Gibson's three components rheological model; the modulus and viscosity coefficient of the rheological model increase with the increasing consolidation pressure.