考虑含水率变化的路基压实填料介电特性试验研究  

Experimental Study on the Dielectric Properties of Subgrade Compacted Filler Considering Changes in Moisture Content

作　　者：王云[1] 付伟[1] 潘喜才 何斌[1] WANG Yun;FU Wei;PAN Xicai;HE Bin(CCCC Second Highway Consultants Co.,Ltd.,Wuhan 430056,China;Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]中交第二公路勘察设计研究院有限公司,武汉430056 [2]中国科学院南京土壤研究所,南京210008

出　　处：《路基工程》2024年第2期77-82,共6页Subgrade Engineering

基　　金：中国交建集团青年科技创新项目(2021-ZJKJ-QNCX16);中交二公院科技项目(KJFZ-2019-041)。

摘　　要：研究介电特性是路基电磁法无损检测技术的基础,为分析路基填料介电特性及其与含水率关系,采用TDR测试砂土、黏性土、改良土、盐渍土等6种典型填料在不同压实度、含水率状态下的介电常数。结果表明:压实填料的介电常数主要受含盐量、含水率、土质类型、压实度等影响;一般路基填料的介电常数主要受控于含水率,压实度在90.0%~96.0%变化时对填料的介电常数影响不显著;一般黏性土、砂性土、改良土的含水率-介电常数关系采用Alharathi模型拟合可满足工程应用精度要求;不同压实度下的Alharathi模型参数较为接近,a=0.100~0.140、b=-0.270~-0.140;掺灰改良土不同压实度的拟合参数差别较大,实际应用中应考虑掺灰比及压实度对介电常数-含水率关系模型的影响。Dielectric properties are the basis of electromagnetic nondestructive testing technology for subgrade.In order to analyze the dielectric properties of subgrade filler and its relation with water content,the dielectric constants of six typical fillers,including sandy soil,clay,improved soil and saline soil,were tested by TDR under different compactness and water content.The results show that the dielectric constant of compacted fillers is mainly affected by salt content,moisture content,soil type,compaction degree,etc.The dielectric constant of conventional subgrade fillers is mainly controlled by moisture content,and the change in compaction degree between 90.0%and 96.0%has no significant impact on the dielectric constant of fillers.The water content-dielectric constant relationship of general cohesive soil,sandy soil,and improved soil can be fitted using the Alharathi model to meet the accuracy requirements of engineering applications.The parameters of the Alharathi model under different compaction degrees are relatively similar,a=0.100−0.140,b=−0.270−−0.140.The fitting parameters of lime improved soil with different compaction degrees are quite different.In practical application,the influence of lime mixing ratio and compaction degree on the relational model of dielectric constant and water content should be considered.

关 键 词：公路路基 压实填料 介电常数 含水率 TDR测试 模型拟合 

分 类 号：TU41[建筑科学—岩土工程]