排水板抽注水淋洗污染液的轴对称消弭简化解析解答

A simplified analytical solution for axisymmetrical dispersion of liquid contaminant due to flushing with PVDs

为简化分析轴对称淋洗条件下土中污染液浓度的消弭过程,借鉴塑料排水板地基固结等应变理论的思想,假定同一深度上污染液浓度的变化速率为其变化速率的平均值,同时依据相关研究成果,忽略竖向渗流和分子扩散作用,采用分离变量法推导得到淋洗过程中任意位置污染液浓度随时间变化过程的简化解析解答,并与现有的解答和室内试验结果进行对比,验证本文简化解答的适用性。研究结果表明:塑料排水板抽、注水淋洗技术显著提高细粒土中污染液浓度的径向消弭速率,竖向渗流和分子扩散作用对污染液浓度消弭的作用影响可以忽略不计。

In order to simplify the analysis of the dispersion process of concentration of liquid contaminant in soil under axisymmetrical flushing conditions, the rate of variation of the concentration of liquid contaminant at the same depth was assumed to be the average value at that depth. This assumption was made with the reference to the idea of equal strain theory of ground consolidation with prefabricated vertical drains（PVDs）. Meanwhile, the effects of vertical seepage and molecular diffusion were ignored based on relevant research outcomes. A simplified analytical solution to the process of variation of concentration of liquid contaminant at any arbitrary position with time was derived using the method of separation of variables. Calculated results were compared with the results from the available solutions and laboratory experiments. The applicability of the proposed solution in this study was verified. The results show that the radial dispersion rate of concentration of liquid contaminant in fine-grained soil is significantly improved by the flushing technique with water injection and extraction using PVDs. The influence of vertical seepage and molecular diffusion on the dispersion of concentration of liquid contaminant can be ignored.