Effects of chemical solutions on the hydromechanical behavior of a laterite/bentonite mixture used as an engineered barrier
Effects of chemical solutions on the hydromechanical behavior of a laterite/bentonite mixture used as an engineered barrier
复制标题
化学溶液对用作工程屏障的红土/膨润土混合物的流体力学行为的影响
DOI：
10.1007/s10064-020-02003-6
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发表时间：
2020-10-17
影响因子：
4.2
通讯作者：
Ye, Wei-min
中科院分区：
文献类型：
--
作者：
He, Yong;Wang, Ming-ming;Ye, Wei-min
压实红土和膨润土以及两者的混合物具有很强的防渗性，可以有效地阻止污染物的迁移和扩散。本研究探讨了采用红土/膨润土混合物作为垃圾填埋场、尾矿池或重金属污染场地的垂直屏障的可行性。对不同干密度、不同配比的膨润土/红土混合试样进行了不同浓度的化学溶液渗透试验和压缩试验。渗透性和固结特性进行了验证，使用扫描电子显微镜。红土样品的导水率随干密度的增加而减小，混合土样品的导水率随膨润土含量的增加而减小。膨润土的加入显著提高了防渗性能。纯红土的导水率为4.7 × 10− 7 cm/s，而掺入20%膨润土的红土样品的导水率为1.6 × 10− 8 cm/s。压实红土与干密度为1.5 g/cm 3的证明，以满足渗透性规格，作为填埋场防渗系统。随着重金属或盐溶液浓度的增加，红土的絮凝作用增强，导水率降低。混合土样中的红土对这些特征有很大影响，特别是降低了导水率。随着化学溶液浓度的增加，压实试样的屈服应力和压缩指数降低，压缩性能提高。这些研究结果表明，化学溶液显着影响的红土/膨润土混合物作为工程屏障的流体力学行为。
Compacted laterite and bentonite, as well as a mixture of the two, are strongly impermeable and can effectively prevent the migration and diffusion of contaminants. This study explored the feasibility of employing a laterite/bentonite mixture as a vertical barrier in landfills, tailings ponds, or sites contaminated by heavy metals. Permeability tests using chemical solutions of different concentrations and compression tests were performed on mixed bentonite/laterite samples with different dry densities and mixing ratios. The permeability and consolidation characteristics were verified using scanning electron microscopy. The hydraulic conductivity of the laterite samples decreased with increased dry density, and the hydraulic conductivity of the mixed-soil samples decreased with increased bentonite content. Adding bentonite significantly improved seepage control performance. The hydraulic conductivity of the pure laterite was 4.7 × 10−7cm/s, whereas that of the laterite sample mixed with 20% bentonite was 1.6 × 10−8cm/s. The compacted laterite with a dry density of 1.5 g/cm3was demonstrated to satisfy the permeability specifications to serve as a landfill seepage control system. When the concentration of the heavy metal or salt solutions increased, the laterite flocculation increased, and the hydraulic conductivity decreased. The laterite in the mixed soil samples substantially affected these characteristics, particularly decreasing the hydraulic conductivity. As the concentration of the chemical solutions increased, the yield stress of the compacted samples and the compression index decreased, and the compression performance improved. These findings indicate that chemical solutions significantly affect the hydromechanical behavior of a laterite/bentonite mixture used as an engineered barrier.