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.

开发了一种二维分析解决方案，以模拟在远离污染物源边缘的横向分层土壤中的蒸汽迁移，并且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。根据现有的分析解决方案，数值模型和实验结果对分析解决方案进行了验证。与现有的VI评估工具相比，它还被证明是评估蒸气侵入（VI）风险的替代筛选工具。研究了污染物源和土壤层特征对VI风险的影响。毛细管条纹的存在有效降低了VI风险。在所有单层土壤案例中，砂的侧向夹杂物区最宽，这是由于毛细管条纹最薄，而土壤与毛细管条纹之间的有效扩散率最低。对于层状土壤，覆盖在较高土壤上的较低有效扩散层会增强水平扩散并扩展横向包裹体带。横向夹杂物区的宽度随源浓度的增加呈对数增加，而随源深度的增加线性增加。根据计算结果，提出了一个简化的公式来初步估计考虑毛细条纹的典型单层土情况下的横向夹杂物区域的宽度。覆盖在较高层上的较低有效扩散层会增强水平扩散并扩展横向包裹体带。横向夹杂物区的宽度随源浓度的增加呈对数增加，而随源深度的增加线性增加。根据计算结果，提出了一个简化的公式来初步估计考虑毛细条纹的典型单层土情况下的横向夹杂物区域的宽度。覆盖在较高层上的较低有效扩散层会增强水平扩散并扩展横向包裹体带。横向夹杂物区的宽度随源浓度的增加呈对数增加，而随源深度的增加线性增加。根据计算结果，提出了一个简化的公式来初步估计考虑毛细条纹的典型单层土情况下的横向夹杂物区域的宽度。