聚醚胺-230处治膨胀土的膨胀-压缩-收缩试验  

Experimental Study on Swelling-compression-shrinkage Behavior of Expansive Soil Treated with Polyetheramine

作　　者：邱煜 卢正[1,3] 颜廷舟 李剑 丁新胜 胡海翔 姚海林[1] QIU Yu;LU Zheng;YAN Ting-zhou;LI Jian;DING Xin-sheng;HU Hai-xiang;YAO Hai-lin(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,Hubei,China;University of Chinese Academy of Sciences,Beijing 100049,China;Hubei Key Laboratory of Geo-Environmental Engineering,Wuhan 430071,Hubei,China;Hubei Communications Planning and Design Institute Co.Ltd.,Wuhan 430051,Hubei,China;China Energy Engineering Gezhouba Rail Transit Construction Co.Ltd.,Shenzhen 518116,Guangdong,China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]中国科学院大学,北京100049 [3]环境岩土工程湖北省重点实验室,湖北武汉430071 [4]湖北省交通规划设计院股份有限公司,湖北武汉430051 [5]中能建葛洲坝轨道交通建设有限公司,广东深圳518116

出　　处：《中国公路学报》2024年第6期111-121,共11页China Journal of Highway and Transport

基　　金：湖北省自然科学基金创新群体项目(2023AFA019);湖北省交通运输厅科技项目(2020-186-1-9)。

摘　　要：基于高效、快速、大面积处治膨胀土的工程需求,以聚醚胺-230作为水溶性膨胀土稳定剂并成功实现对膨胀土的快速处治。模拟常规路基施工中配制含水率后的压实填筑方法,讨论聚醚胺水溶液代替水按照掺入配比的方法处治膨胀土的效果与土壤特性变化。通过膨胀、固结与收缩试验比较了膨胀土与不同聚醚胺-膨胀土质量比对应处治土的膨胀、压缩与收缩特性。结果表明:聚醚胺的迅速吸附能抑制并调控膨胀土的膨胀与收缩劣害性,同时使压实处治土展现出土壤结构的强化特性。处治土的膨胀、压缩和收缩指标均显著降低;样品制备为干密度1.62 g·cm^(-3)时,膨胀土可被处治为低膨胀性、低收缩性、中压缩性的处治土。基于吸附机理,聚醚胺的掺入量主要影响着处治效果,但存在处治极限即无法完全抑制膨胀与收缩特性。主要处治机理通过对扫描电子显微镜图像与膨胀土中黏粒部分的X-衍射分析进行表征,干燥的提取黏粒中蒙皂石层间距1.49 nm变化为处治后的1.36 nm,可解释为聚醚胺的插层效应导致蒙皂石矿物层间的离子水化受到抑制。聚醚胺单层平铺吸附于蒙皂石矿物层间,层间钙离子无法水化至2层水分子以上扩大层间距。土壤颗粒表面水敏性显著降低,土壤微观结构图像直观地揭示了聚醚胺在膨胀土中的吸附导致的水化抑制与土壤结构强化效应。To address the engineering need for an efficient,rapid,and large-scale approach for treatment of expansive soils,polyetheramine-230 was successfully utilized as a water-soluble stabilizer for expansive soils in this study.Common compaction and filling techniques with varying moisture levels typically employed in the traditional road construction were emulated.The aim was to assess the impact of substituting water with a polyetheramine solution,following specific mixing ratios,on the treatment of expansive soils and its influence on soil properties.Swelling,consolidation,and shrinkage tests were conducted to compare the treatment effects on expansive soils,and different mass ratios of polyetheramine-treated expansive soils were analyzed.The swift adsorption capacity of polyetheramine effectively mitigates the expansion and shrinkage tendencies of expansive soils,bolstering the structural characteristics of the compacted treated soil.When the specimen is prepared with a dry density of 1.62 g·cm^(-3),the expansive soil can be effectively treated to exhibit a low expansivity,minimal shrinkage,and moderate compressibility.The treatment efficacy is primarily influenced by the dosage of polyetheramine,guided by adsorption mechanisms.However,there exists a treatment threshold,beyond which the complete suppression of expansive and shrinkage characteristics becomes unachievable.The key treatment mechanism was elucidated through an X-ray diffraction analysis of the clay fraction within the expansive soil and scanning electron microscopy images.The initial interlayer spacing of native clay of 1.49 nm decreases to 1.36 nm.This phenomenon can be elucidated by the intercalation effect of polyetheramine,which hinders the ion hydration within the interlayers of montmorillonite minerals.The polyetheramine monolayer uniformly adsorbs onto the montmorillonite mineral layers,impeding the hydration of interlayer calcium ions beyond two layers of water molecules and thereby contracting the interlayer spacing.Furthermore,the water sens

关 键 词：路基工程 膨胀土 试验研究 稳定剂 膨胀 压缩 收缩 聚醚胺-230 

分 类 号：U416.1[交通运输工程—道路与铁道工程]