含水量对珠三角软土时效变形特性影响试验分析与模型研究

Experimental analysis and model study on the influence of water content on the aging deformation characteristics of soft soil in Pearl River delta

软土时效变形特性对于建筑物的稳定性有着重要影响.通过室内直剪蠕变试验,在相同试验条件下完成了5组不同含水量及不同应力水平试样时效变形特性的测试,获得了试样含水量与时效变形特性的关系,研究含水量对珠三角软土时效变形特性的影响.试验结果表明,该地区软土变形时效特性明显,含水量是影响软土时效变形特性的重要因素之一.采用五元件Kelvin模型和西原正夫模型对试验曲线进行拟合分析,两个模型在不同含水量、不同应力水平组合下的拟合与试验结果都具有良好的一致性,且两个模型拟合效果具有互补性.引入邓肯-张模型非线性E-v模型,使西原正夫模型在低含水量低荷载时的拟合效果显著提高.

The time-dependent deformation characteristic of soft soil has an important influence on the stability of the building. Through direct shear creep test in laboratory, 5 groups of different water content and different stress levels of the sample time-dependent deformation characteristics were tested under the same conditions, the relationship between water content of the specimen and the time-dependent deformation characteristics was obtained, and the effect of water content on the time-depent deformation characteristics of the soft soil in the Pearl River Delta was studied. Results show that the obvious time-characteristic of the soft soil and the water content is one of the important factors affecting the time-dependent deformation characteristic of soft soil. The five component Kelvin model and Nishihara Masao model were used to analyze the experimental curves. The fitting and experimental results of the two models under different water content and different stress levels had good consistency, and the fitting effects of the two models were complementary. The nonlinear E-v model of Duncan-Chang model is introduced to improve the fitting effect of Nishihara Masao model at low water content and low load.