摘要
采用磷石膏改良膨胀土可以同时实现磷石膏的资源化利用和膨胀土的改良。以引江济淮Y003标段的中膨胀土为例,通过液限、塑限、击实、膨胀率、直剪和崩解试验对磷石膏改性膨胀土的工程特性演变规律进行研究。结果表明:改性土的液限与塑性指数均低于素膨胀土,其中50%(质量百分比)掺量的磷石膏混合土液限较素膨胀土下降了19.7个百分点,塑性指数下降了20.3;改性土的膨胀率均低于素膨胀土,50%掺量的磷石膏混合土自由膨胀率较素膨胀土下降了36个百分点,无荷膨胀率下降了5.12个百分点;随着磷石膏掺量的增加,改性土的内摩擦角逐渐增大,黏聚力逐渐降低;磷石膏的掺入导致改性土的抗崩解能力下降,实际应用中要考虑添加其他胶凝材料。研究成果可为类似工程膨胀土改性提供参考。
Using phosphogypsum to improve expansive soil can simultaneously achieve the resource utilization of phosphogypsum and the improvement of expansive soil′s swelling characteristics.Taking the expansive soil from section Y003 of the Yangtze-to-Huaihe River Water Diversion Project as an example,we investigated the engineering properties evolution law of phosphogypsum-modified expansive soil through liquid limit,plastic limit,compaction,swelling rate,direct shear,and disintegration tests.The results showed that:the liquid limit and plasticity index of the modified soil were lower than those of the untreated expansive soil.When the phosphogypsum content was 50%(mass percentage),the liquid limit decreased by 19.7 percentage points,and the plasticity index decreased by 20.3 compared to the untreated soil.The swelling rate of the modified soil was consistently lower than that of the untreated soil.When the phosphogypsum content was 50%,the free swelling rate decreased by 36 percentage points and the load-free swelling rate dropped by 5.12 percentage points.As the phosphogypsum content increased,the internal friction angle of the modified soil gradually rose,while the cohesion gradually declined.The addition of phosphogypsum reduced the soil′s resistance to disintegration,so other cementitious materials was suggested to add in practical applications.This research provides a reference for similar projects that use modified expansive soil.
作者
胡波
李浩洋
童军
王卫
查恒
夏锐
HU Bo;LI Haoyang;TONG Jun;WANG Wei;ZHA Heng;XIA Rui(Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Changjiang River Scientific Research Institute,Wuhan 430010,China;College of Civil Engineering and Architecture,China Three Gorges University,Yichang 443000,China;Yangtze Eco-Environment Engineering Research Center,China Three Gorges Corporation,Beijing 100038,China;Anhui Provincial Group Limited for Yangtze-to-Huaihe Water Diversion,Hefei 231299,China)
出处
《人民长江》
北大核心
2025年第5期156-161,共6页
Yangtze River
基金
国家自然科学基金项目(51008035)
中央级公益性科研院所基本科研业务费项目(CKSF2023327/YT)
安徽省引江济淮工程科技创新项目(YJJH-ZT-ZX-20230118528)。
关键词
膨胀土
磷石膏
资源化利用
工程特性
引江济淮工程
expansive soil
phosphogypsum
resource utilization
engineering properties
Yangtze-to-Huaihe River Water Diversion Project
