垃圾土的复合沉降模型研究

Study on Composite Settlement Model for Refuse

垃圾土的沉降包括荷载作用后发生的瞬时沉降、物理蠕变和生化降解3部分。但实际上,物理蠕变和生化降解在整个垃圾土的沉降过程中很难准确区分。因此,本文提出一种新的复合沉降模型,认为整个垃圾土的沉降可以分为2部分,第1部分为由于应力作用产生的瞬时沉降,第2部分综合考虑了垃圾土中的蠕变和生化降解,这里称为长期沉降。根据对自行设计的室内沉降试验装置中各观测点沉降值的非线性回归分析,得到复合沉降模型中的各参数值,并用各观测点参数的平均值得出模型计算值。结果表明,计算值与观测值吻合较好。

The settlement of refuse includes instantaneous settlement in response to applied load, mechanical creep and biological decomposition. In fact, mechanical creep and biological decomposition could not be explicitly distinguished during the process of refuse settlement. Therefore, in this paper, a new composite settlement model was established. The settlement could be divided into two parts, one was instantaneous settlement in response to applied load, and the other was long term settlements which comprehensively included mechanical creep and biological decomposition. According to the nonlinear regression analysis on settlement values which were observed in the interior settlement test instrument designed by the authors, the parameter values of the model were obtained. Furthermore, with the averaged parameter values of the observations points, the calculated values of the model were achieved. The results indicated that the calculated values were in good agreement with the observed data.