Parametric sensitivity analysis of coupled mechanical consolidation and contaminant transport through clay barriers
Parametric sensitivity analysis of coupled mechanical consolidation and contaminant transport through clay barriers
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DOI：
10.1016/j.compgeo.2008.04.003
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发表时间：
2009
影响因子：
5.3
通讯作者：
T. Lewis;P. Pivonka;S. Fityus;David C. Smith
中科院分区：
文献类型：
--
作者：
T. Lewis;P. Pivonka;S. Fityus;David C. Smith
在本文中，一个广泛的参数敏感性分析的耦合固结和溶质运移的复合填埋场衬垫系统已进行。该分析采用了3000多个模拟的结果的各种组合的屏障厚度，废物装载率，初始孔隙比，压缩指数，水力传导系数和分散系数。然而，值得注意的是，为了限制研究的范围，在这里提出的分析中假设固结系数为常数，尽管该假设很容易放松。参数敏感性分析的结果简洁地提出了使用无量纲图，它允许大量的参数值的结果进行比较，因此，通过班轮系统的污染物运输的最重要的决定因素的明确识别。无量纲图显示了一个最小值（对于该值，“突破时间”被最小化）。数值结果表明，在极端衬垫压缩性的情况下，由于溶质运移和固结之间的耦合，污染物的过境时间可能会出现一个数量级的减少，而对于低压缩性和孔隙率的障碍物（如精心设计的复合压实粘土填埋场衬垫），污染物的过境时间仍然可以减少30%以上。数值结果表明，使用耦合固结污染物传输模型有时需要知情和保守的填埋场衬垫设计。
In this paper, an extensive parametric sensitivity analysis of coupled consolidation and solute transport in composite landfill liner systems has been undertaken. The analysis incorporates results of more than 3000 simulations for various combinations of barrier thickness, waste loading rate, initial void ratio, compression index, hydraulic conductivity and dispersion coefficient. However, it is noted that to limit the extent of the study a constant coefficient of consolidation is assumed in the analysis presented here, though this assumption is easily relaxed. Results of the parametric sensitivity analysis are succinctly presented using dimensionless plots, which allow the comparison of results for a large number of parameter values, and so the clear identification of the most important determinants on contaminant transport through the liner system. The dimensionless plots demonstrate a pessimum (for which the ‘breakthrough time’ is minimised). Numerical results reveal that in cases of extreme liner compressibility an order of magnitude reduction in contaminant transit time may arise due to coupling between solute transport and consolidation, while for barriers of low compressibility and porosity (such as well-engineered composite compacted clay landfill liners), it is found that the contaminant transit time may still be reduced by more than 30%. The numerical results suggest that the use of coupled consolidation–contaminant transport models are sometimes required for informed and conservative landfill liner design.