Water-absorbing polymer (WAP) amendment is emerging as a sustainable soil management technique in various geoenvironmental projects for controlling the subsurface water flow in the vadose zone. The addition of WAP can alter the pore structure and improve water-retention characteristics of the soil. The existing water-retention characteristic curve (WRCC) models for polymer-amended soils are complex and require a number of empirical parameters, which cannot be easily obtained through simple laboratory experimentation. The current study proposes a simple predictive WRCC model for WAP-amended soils based on the understanding that WAP particles absorb and retain water within their polymer structure and therefore influence the void ratio. The proposed model captures the change in the void ratio of the amended soil through a modified phase relationship for predicting WRCC. The performance of the model was validated for four different textured soils with varying WAP concentrations. The comparison between measured and predicted WRCC indicates that the proposed model can capture the changes in the void ratio as well as the WRCC with adequate accuracy.

中文翻译：

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吸水聚合物改良土保水曲线预测模型

吸水聚合物 (WAP) 修正剂作为一种可持续的土壤管理技术出现在各种地质环境项目中，用于控制包气带中的地下水流。加入WAP可以改变土壤的孔隙结构并改善土壤的保水特性。现有的聚合物改性土壤保水特性曲线（WRCC）模型复杂，需要大量经验参数，这些参数无法通过简单的实验室实验轻易获得。目前的研究基于 WAP 颗粒在其聚合物结构中吸收和保留水分并因此影响孔隙比的理解，提出了一个简单的 WAP 修正土壤的预测 WRCC 模型。所提出的模型通过用于预测 WRCC 的修正相位关系捕捉修正土壤的孔隙比的变化。该模型的性能在四种不同质地的土壤中进行了验证，这些土壤具有不同的 WAP 浓度。实测和预测的 WRCC 之间的比较表明，所提出的模型可以以足够的精度捕捉空隙率和 WRCC 的变化。