Engineered surface barriers are used to isolate subsurface contaminants for effective long‐term containment of waste of a variety of types. The impact depths of a surface barrier are affected by the pre‐barrier recharge rate and the properties of the soil beneath the barrier. In this paper, algebraic expressions are developed to estimate drainage velocities and barrier impact depths after the emplacement of a surface barrier. Four impact depth terms are used to convey barrier impact: the near‐zero‐, 50%, average‐, and full‐impact depths. The algebraic expressions show that the average‐impact depth is no more than one‐third of the near‐zero‐impact depth, whereas the 50% impact depth is slightly larger than one‐half of the near‐zero‐impact depth. The full‐impact depth, depending on the final recharge rate from the surface barrier, is usually much smaller than the other impact depths. These differences lead to a very large transition zone beneath a surface barrier. A field drainage experiment and a series of numerical simulations were used to test the algebraic expressions. The experimental data and numerical results corroborated the analytical models by predicting very similar water content profiles and/or near‐zero‐, 50%, average‐, and full‐impact depths during the drainage process. The algebraic expressions provided are useful for quickly identifying sites where the depth of the existing contaminants could be beyond the protection of a surface barrier.

中文翻译：

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用于估计均质土壤上表面障碍的冲击深度的代数表达式

工程表面屏障用于隔离地下污染物，以有效地长期遏制各种类型的废物。屏障的冲击深度受屏障前的补给率和屏障下方土壤的性质影响。在本文中，发展了代数表达式来估计表面屏障放置后的排水速度和屏障冲击深度。四个影响深度术语用于传达屏障影响：接近零，50％，平均和完全冲击深度。代数表达式显示平均冲击深度不超过接近零冲击深度的三分之一，而50％冲击深度略大于接近零冲击深度的一半。完整的冲击深度，取决于表面障碍物的最终充电速度，通常比其他冲击深度小得多。这些差异导致表面势垒下的过渡区非常大。通过现场排水实验和一系列数值模拟来测试代数表达式。通过预测排水过程中非常相似的含水量曲线和/或接近零，50％，平均和全冲击深度，实验数据和数值结果证实了分析模型。提供的代数表达式可用于快速识别现有污染物的深度可能超出表面屏障保护范围的位置。通过现场排水实验和一系列数值模拟来测试代数表达式。通过预测排水过程中非常相似的含水量曲线和/或接近零，50％，平均和全冲击深度，实验数据和数值结果证实了分析模型。提供的代数表达式可用于快速识别现有污染物的深度可能超出表面屏障保护范围的位置。通过现场排水实验和一系列数值模拟来测试代数表达式。通过预测排水过程中非常相似的含水量曲线和/或接近零，50％，平均和全冲击深度，实验数据和数值结果证实了分析模型。提供的代数表达式可用于快速识别现有污染物的深度可能超出表面屏障保护范围的位置。