Research On Improving Mechanism And Application Of High Water Content Silt Solidification

At present,the development of China's transportation construction is changing rapidly,and at the same time,it is also facing many problems and challenges.One of the main problems is the treatment of roadbed embankment fillers with poor engineering properties.Therefore,research on soil improvement is becoming more and more important.As a commonly used soil improver,quicklime has a good improvement effect,but it also has the disadvantages of high cost,difficulty in preservation,and easy soil compaction in improved soil.As a kind of industrial and agricultural waste,grass ash can reduce the water content of silt,improve the permeability and engineering properties of silt.Based on the background of the Bengbu-Wuhe Expressway embankment filling project in Huaibei area,this paper uses grass ash-lime modifier to improve the high moisture content silty embankment filler.The main contents are studied as follows:(1)Conduct a study on the effect of grass ash-lime modifier on the silt moisture content.First,through the gradient modifier single-mixed water content loss test,the precipitation law of limemodified soil and grass-ash-modified soil was obtained.On this basis,the modifier double-mixed mixture ratio program was developed to conduct the modifier double-mixed water content loss test to obtain double-mixed The law of water content loss of silty soil with modifier.SPSS software was used to fit the silt moisture loss data,and the relationship model between grass ash-lime modifier ratio,time and silt moisture content was established,and the analytic hierarchy process was used to analyze the factors obtained by SPSS software on silt moisture content.The weight of the rate is tested.(2)Through the basic geotechnical test and SEM and other tests,the improvement mechanism of grass ash-lime improver was analyzed from the aspects of water content reduction and strength improvement.Through the basic geotechnical tests,the physical and mechanical properties of the silt before and after the improvement are studied and analyzed;the SEM test is used to study the changes of the silt particles and the structure of the silt before and after the improvement;the EDS test and XRD test are used The elements and compounds are analyzed.Combining macro and meso phenomena,research and analyze the improvement mechanism from three aspects of physical? chemical and mechanics.(3)From the field construction technology and field test of high moisture content silty roadbed improvement,the field application of the roadbed improvement of Bengwu Expressway project is studied,which provides reference for similar roadbed embankment filling engineering.The construction technology of high water content silt embankment filling includes construction preparation,precipitation in borrow pit,loading and transportation,embankment filling construction and repair and acceptance.Through field tests,the modifier mix ratio under different embankment filling requirements is selected.(4)According to the macro and meso soil parameters obtained from the field experiments and indoor experiments,the FLAC3 D numerical simulation software is used to establish a numerical simulation model of the high moisture content silty subgrade,the post-construction settlement of the silty soil before and after improvement is analyzed,and the vehicle load The road performance and stability of the high-moisture silt embankment before and after improvement are studied.The paper has 61 pictures,28 tables,and 64 references.