Numerical Analysis Of Mudstone Embankment Under Rainfall Infiltration And Study Of Treatment Measures

Mudstone is a kind of materials between hard rock and soil,widely distributed in our country.Mudstone has the characteristics of low compressive strength,easy weathering,easy to soften and disintegrate in water,the filling compactness is sensitive to moisture content,which is very unfavorable to the road construction.Therefore,this thesis in view of characteristics of mudstone,mudstone embankment rainfall infiltration and corresponding treatment measures are studied,theoretical analysis and experimental study in this thesis,the work which has been carried out is as follows:(1)Indoor experimental research of mudstone was done,results show that the bearing ratio of mudstone meets the requirements of embankment,and mudstone can be used as embankment filer.But mudstone belongs to soften rocks,the intensity is reduced in water,so the selection of mudstone as the embankment filling should pay special attention to waterproof.(2)Improved experiment of mudstone was done,the water stability and bearing ratio of mudstone can be enhanced when mudstone was improved by cement or lime.In this paper,lime is recommended to improve the mudstone,not only because of the lime is cheap,but also the lime has the best lime mixing ratio.(3)One dimensional seepage model of unsaturated soil embankment in combination with boundary condition of FDEM simulates the dynamic rainfall infiltration process.The moisture content of calculated values has high similarity with measured values,proved the applicability and scientific of above model to solve mudstone embankment moisture content.The moisture content calculation result shows that the clay seal coat can reduce the rainfall infiltration rate and the influence depth of rainfall to the embankment.Two methods have been put forward to calculated the amount of water-blocking,the calculation results shows that a large amount of rainwater can be blocked outside of mudstone embankment when the clay seal coat was paved on the mudstone embankment,the mudstone can be protected by clay seal coat.(4)The clay seal coat was paved on the mudstone for experimental study,Quantitative study on the different influencing factors of moisture content of mudstone embankment,including the thickness of the clay seal coat,the depth of embankment,the weathering degree of mudstone,and the drying time.The reasonable thickness of clay seal coat was put forward for the construction of mudstone embankment of Anhui province.Statistical regression forecast model of mudstone embankment moisture content are put forward.The depth of mudstone under the condition of the optimum moisture content after rained can be calculated according to prediction model,then dig and ted the embankment,engineering quantity and time will be saved.(5)Test section was selected for study of impact rolling experiment,result shows that 20 times of impact compaction is advisable,using the impact copaction technology when the filling thickness of mudstone embankment is 12 cm,and that can play a good compaction effect.