Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China.
J Contam Hydrol. 2020 Aug;233:103664. doi: 10.1016/j.jconhyd.2020.103664. Epub 2020 Jun 10.
A two-dimensional analytical solution is developed to simulate vapor migration in layered soil laterally away from the edge of contaminant source and has advantages in considering the vapor concentration profile in a functional form near the source edge. The analytical solution is validated against existing analytical solution, numerical model and experimental results. It has also proved to be an alternative screening tool to evaluate the vapor intrusion (VI) risk by compared with existing VI assessment tools. The influence of the characteristics of contaminant source and soil layer on the VI risk are investigated. The existence of capillary fringe effectively reduces VI risk. Among all the single-layer-soil cases, the lateral inclusion zone for sand is the widest due to the thinnest capillary fringe and the lowest effective diffusivity ratio between soil and capillary fringe. For layered soil, the lower effective diffusivity layer overlying the higher one enhances the horizontal diffusion and extends the lateral inclusion zone. The width of lateral inclusion zone increases logarithmically with increasing source concentration while it increases linearly with increasing source depth. Based on the calculation results, a simplified formula is proposed to preliminarily estimate the width of lateral inclusion zone for the typical single-layer-soil cases considering the capillary fringe.
开发了一种二维解析解来模拟污染物源边缘横向的分层土壤中的蒸汽迁移，在考虑源边缘附近功能形式的蒸汽浓度分布方面具有优势。该解析解通过与现有的分析解、数值模型和实验结果进行对比，得到了验证。通过与现有的 VI 评估工具进行比较，它也被证明是评估蒸气入侵 (VI) 风险的一种替代筛选工具。研究了污染物源和土层特征对 VI 风险的影响。毛细带的存在有效地降低了 VI 风险。在所有单层土壤情况下，由于毛细带最薄且土壤与毛细带之间的有效扩散率比值最低，砂层的横向包含区最宽。对于分层土壤，覆盖在较高土层上的较低有效扩散率层增强了水平扩散并扩展了横向包含区。随着源浓度的增加，横向包含区的宽度呈对数增加，而随着源深度的增加，横向包含区的宽度呈线性增加。基于计算结果，提出了一个简化公式，可初步估算考虑毛细带的典型单层土壤情况下的横向包含区的宽度。
