滨海吹填土固结蠕变特性试验研究

Experimental Study of Consolidation Creep Property of Seashore Dredger Fill

围海造陆形成的吹填土地基与天然形成地基的工程特性存在诸多差异,为了保证吹填土地基的长期稳定性和安全性,有必要揭示吹填土与天然土工程特性的差异。利用单向固结仪,开展了不同加荷方式下滨海典型软土和围海造陆吹填土的蠕变特性试验对比研究,得到了不同试验条件下土体的应变、应力和时间的关系,对比分析两种软弱土蠕变性状的差异和影响因素,同时给出次固结系数的变化规律。试验结果表明,分级加载下两种滨海软土均具有明显的非线性蠕变特性,高应力水平下经排水加固的吹填土最终变形量明显低于软黏土,而次固结变形较大;吹填土的一维固结蠕变特性受加荷比和试样高度影响,加荷比越大、高度越高土样最终蠕变量越大;次固结系数与加荷比和荷载等级有关,表现为次固结系数随荷载增大先增大后减小,峰值随加荷比增大而减小。

It＇ s important to reveal the different characteristics of the foundation works between dredger fill foundation formed by reclamation land and natural foundations in order to ensure the long-term stability and security of dredger fill foundations. By the unidirectional oedometer apparatus, the comparative creep tests in different loading methods is done, the relationship of stress, strain and time is gotten, the differences and influencing factors in creep characteristics between these two kinds of soil are compared, and the variation on coefficients of secondary consolidation is done. The research indicates： the creep character of these two kinds of soil in littoral area is nonlinear. The deformation of dredger fill soil reinforced by drainage is significantly lower than the soil in littoral area with higher level, and the deformation of secondary consolidation is more ; The creep properties of dredger fill from one-dimensional consolidation are obviously impact by loading and the sample height, the creep deformation is more with higher loading ratio and bigger sample height; Coefficient of secondary consolidation is controlled by the loading ratio and load rating, which performance as first increases with the load increases and then decreases, meanwhile the peak reduced with the loading ratio decrease.