Design Of Granular And Analysis Of Pavement Performance Of Changsha City

Based on the road project in Wuguang regional Changsha City , through investigation, analysis and summary of the graded broken stone layer related technologies used in pavement structure at home and abroad,using the techniques such as the combination of laboratory test and construction site test,the combination of engineering application and post-trace detection,the combination of theoretical analysis and 3D finite element analysis,In this paper,we have conducted relating research in the performance difference between the graded broken stone layer used in typical road pavement structure and China's traditional semi-rigid pavement structure.At the beginning of this paper,grading design method of the graded broken stone is studied. With reference of the successful application experience of granular base home and abroad and according to the requirements of specifications and grading control points,we design three type's graded broken stone with continuous gradation. And also,relying the model which the Beiley method design Coarse-graded mixture,combining with certain constraints of the target gradation , setting up linear programming model,we design one type's graded broken stone with dense framework gradation.Secondly, the properties of the graded broken stone are studied. For the above four gradation's graded broken stone,this paper put forward the concept of grading parameters and focus on the properties experiment of raw materials,maximum dry density,optimum water content,void rate,CBR value,resilient modulus and analyze the relationship between grading parameters and properties.Finally,with making use of the large finite element analysis software to establish pavement structure's 3D model and fully considering the elastic-plastic of graded broken stone,We have analyzed mechanical response of the four pavement structure under the action of single rectangular uniform pressure load, which are flexible pavement structure,inverted asphalt pavement structure,cement stabilized soil base course pavement structure,lime stabilized soil base course thicken pavement structure; By varying the thickness and resilient modulus of structure layer,we have taken sensitivity analysis on the peak of the four pavement structure's mechanical indicators. The road surface deflection's difference between field testing and finite element analysis is given comparative analysis. We present some of the views to improve the pavement structure and material properties and put forward suggestions for further research work.