Application Of High Liquid Limit Soil In Subgrade Filling In Fujian Province

High liquid limit soil is widely distributed in coastal areas in Fujian Province,but the highway construction fill is so large that discarding the kind of soil is notonly a waste of resources, but also need a large areas of the heap landfill, and that themethod to find soil source with good engineering performance is also expensive andwould cause environmental damage, and that the improved methods, with difficultyconstruction, would extend the duration and increase project costs. Therefore,whether to improve or change to fill are unrealistic.A large number of practice hasproved that high liquid limit soil can be directly used for highway subgrade filling.For rain-fed areas in Fujian, how to ensure high liquid limit soil subgrade strengthand stability are key issues in highway subgrade filling.This article focuses on the key technical problems how to improve soilcharacteristics for directly subgrade filling through the construction process, relyingon the project of high liquid limit soil embankment filling on Shunchang line ofJingfu Expressway, through the literature on high liquid soil research, field surveys,laboratory and field tests, study the construction technology about high liquid limitsoil filling subgrade. The main work and the conclusions were as follows:First, by the physical and mechanical properties testing on the typical highliquid limit soil in Fujian Province, analyzed the basic physical and mechanicalproperties of high liquid limit soil. From a high liquid limit soil composition andstructure of three-phase point of view, the high liquid limit soil compactionmechanism is analyzed with the impact of compaction factors including moisture,soil type, thickness, rolling equipment and rolling times.Secondly, combined with the high liquid limit soil filling subgrade testengineering in Shunchang line of Jinfu Expressway, based on theoretical and indoorpilot study, regarded dry density and saturation as quality control indicators for highliquid limit soil subgrade filling, and analyzed change law of the best dry density andsaturation to ensure high liquid limit soil strength; raised the method to determinerolling parameters, discussed variation law of rolling parameters for different kindsof high liquid limit soil; integrating the test with other tests in Fujian Provinceshowed that high liquid limit soil can be used not only in Area90of subgrade filling,but also Area93. Take the example of Quanxia Expressway embankment filling withhigh liquid limit to prove that embankment has good strength and stability.Finally, from on-site construction point of view, researched on a set ofconstruction technology for high liquid limit soil subgrade filling, pointed out thefilling construction content and proposed indicators and standards for theconstruction and testing process; explained the construction control methods for avariety of factors affectting the quality of subgrade filling, including moisture content, rolled several times, crushing equipment, thickness, rolling procedures. Atlast, summed up the types and causes of typical disease on the high liquid limit soilembankment and the appropriate punishment measures.Based on the obove, with a view to provide the technical reference for the highliquid limit soil in the subgrade construction applications.