考虑新近吹填土固结系数为变量的固结理论研究

Consolidation theory considering coefficent of consolidation of hydraulic fill as variable

围海造陆吹填区内吹填土加固前为泥浆状态,含水率高达80%以上,初始孔隙比较大。加固过程中孔隙比变化较大,与正常固结土有着一定的区别。传统的固结理论假定渗透系数不变,利用传统固结理论计算吹填土的固结与实测值存在着较大的偏差。通过室内试验得出吹填泥孔隙比随固结应力的变化关系以及渗透系数与空隙比的关系,最终建立渗透系数随固结应力的变化关系;考虑加固过程中渗透系数随加固时间是变化的,对巴隆固结理论进行改进;利用改进后的固结理论对吹填土真空预压模型试验进行计算,计算结果与试验基本吻合,表明采用本文提出的变参数固结理论计算能取得很好的计算效果。

The hydraulic fill in the reclaimed area is in a slurry state with high water contant of over 80% and large initial void ratio.The void ratio may greatly change during the reinforcement of vacuum preloading,and it is essentially different from that of normally consolidated soil.The conventional consolidation theory supposes the coefficient of permeability as constant,the calculated results of the consolidation of hydraulic deviate from those of the field tests.In order to improve the calculated results,laboratory tests are carried out.The relationship between the void ratio and the consolidation stress is obtained from the laboratory tests,and that between the permeability coefficient and the void ratio is proposed.At last,the relationship between the permeability coefficient and the consolidation stress is put forward.The Barron’s consolidation theory is improved by considering the coefficient of permeability to vary with time.A calculation is conducted to a vacuum preloading model test,the results are in accordance with the test data.It shows that the improved consolidation theory is suitable to the vacuum preloading of hydraulic fill.