Numerical modeling of water dynamics in Railway embankments

This dataset contains input parameters for numerical modeling using HYDRUS to simulate water flow under railway embankments. It was generated to investigate water flow dynamics and distribution in railway embankments, with implications for the transport of herbicides affecting tracks and underlying structures. Numerical experiments using a univariate approach assessed how embankment and site-specific factors influence water content and flow patterns. Key parameters included hydraulic properties (saturated/residual water content, Van Genuchten parameters, and hydraulic conductivity), recharge rate, groundwater level, horizontal impermeable layers, and embankment thickness. The data for the reference model was based on drilling information from the funder and the hydraulic parameters estimated with the help of ROSETTA (Hydrus tool). The results were later visualized and post-processed in ParaView by importing the VTK files from Hydrus. Analysis of percolation fronts and flow paths identified groundwater levels and the Van Genuchten parameter (α) as the most influential factors. The simulations mimicked soil with and without moisture conditions (i.e. 30 days of average recharge rates in Germany). All the folders contain the input files for each scenario for the soil moisture conditions. To run the simulations without soil moisture conditions, exchange the file Atmosph.in for the file in the folder amts_dry. Brief description of the following parameters that were inspected (values of the parameters are written on the file name): 1. α (Van Genuchten Shape Parameter) - (1/m) controls the air entry value of the soil-water retention curve. 2. 𝑛 (Van Genuchten Pore-Size Distribution Parameter) - (dimensionless) defines the pore-size distribution's impact on the soil-water retention curve. 3. IMP - lower permeable Layer refers to a less permeable horizontal layer introduced at multiple depths (m) in the simulation domain. 4. GW - Groundwater Levels (m) indicates the depth or position of the groundwater table relative to the embankment structure. 5. qs - The saturated water content (dimensionless) represents the maximum volumetric water content of the soil, corresponding to full saturation. 6. qr - The residual water content (dimensionless) indicates the volumetric water content below which water movement ceases due to adhesion forces. 7. Kf - Saturated hydraulic conductivity (m/s) measures the soil's ability to transmit water under fully saturated conditions. 8. EMB - Embankment Thickness (m) defines the height or vertical extent of the embankment structure. It directly influences the overall storage capacity and the flow path lengths within the embankment, affecting water content distribution and hydraulic response.本数据集包含使用HYDRUS模型开展铁路路堤下水流数值模拟所需的输入参数。本数据集的构建旨在探究铁路路堤内部的水流动力学特性与分布规律，其研究成果可为影响轨道及下部结构的除草剂迁移过程分析提供支撑。研究采用单变量方法开展数值试验，以评估路堤及场地专属因素对土壤含水率与流场分布的影响。核心参数涵盖水力特性参数（饱和含水率、残余含水率、Van Genuchten参数（Van Genuchten parameters）以及饱和导水率）、补给速率、地下水位、水平隔水层以及路堤厚度。参考模型的数据基于资助方提供的钻探资料，且借助ROSETTA（HYDRUS配套工具）估算得到水力参数。后续通过导入HYDRUS生成的VTK文件，在ParaView中完成结果可视化与后处理。通过对渗流锋面与径流路径的分析，确定地下水位与Van Genuchten参数α为影响最为显著的控制因子。 本次模拟涵盖含土壤水分条件与不含土壤水分条件两种场景（即德国地区30天平均补给速率情境）。所有文件夹均包含对应土壤水分条件下各情景的输入文件。若需运行无土壤水分条件的模拟，只需将Atmosph.in文件替换为amts_dry文件夹内的对应文件即可。下文对本次研究涉及的参数进行简要说明（参数取值标注于文件名中）： 1. α（Van Genuchten形状参数）：单位为(1/m)，用于控制土壤水分特征曲线的进气值。 2. n（Van Genuchten孔径分布参数）：无量纲，用于表征孔径分布对土壤水分特征曲线的影响程度。 3. IMP（低渗透层）：指在模拟域内多深度处布设的低渗透性水平层，单位为m。 4. GW（地下水位）：指地下水位相对于路堤结构的埋深或位置，单位为m。 5. qs（饱和含水率）：无量纲，代表土壤的最大体积含水率，对应完全饱和状态。 6. qr（残余含水率）：无量纲，指因黏附力作用导致水分运动停止时的体积含水率阈值。 7. Kf（饱和导水率）：单位为m/s，用于衡量土壤在完全饱和条件下的输水能力。 8. EMB（路堤厚度）：指路堤结构的高度或竖向延伸范围，单位为m。该参数直接影响整体储水能力与路堤内部径流路径长度，进而改变含水率分布与水力响应特性。