Study On Optimal Design Of The Grading Crushed Stone In The Seasonal Frozen Region

In our country, the semi-rigid base asphalt pavement structure has become the majorstructure of highway asphalt pavement. However, all sorts of problems appeared along withthe semi-rigid base being used, highway builders gradually set their sight on the flexible basestructure which has good performance in foreign countries. As an important part of theflexible base, the performance of graded crushed stone is very important to the performanceof the flexible base. In order to guarantee the flexible base play good performance in seasonfrozen area, and according to the characteristics of environment, material and structure inseason frozen area, carry out material optimum design of graded crushed stone in seasonfrozen area is very necessary.Firstly, based on the analysis of the survey, this paper summarizes the applicationconditions and use scope of the graded crushed stone base at home and abroad. And from thepoint of the stress in structure, this paper analyzes the stress level of graded crushed stonebase. According to the results of analysis, this paper proposes the function and userequirement of graded crushed stone base. Secondly, the major material index which hasinfluence on the graded crushed stone performance are studied, and this paper puts forwardthe new material index according to the environment characteristics of the flexible base.Through the study of material structure and strength theory of graded crushed stone, thispaper puts forward the framework dense structure design method of graded crushed stonewhich suitable for season frozen area; According to the theory of granular mechanics, thispaper discusses critical damage condition of the graded crushed stone materials, and putsforward the graded crushed stone shearing index, and checks the designed structure. Throughthe analysis of deformation mechanism, design the simulation test for the graded crushedstone deformation, and estimate the ability of graded crushed stone resistance to deformation.Finally, according to the research results of above, this paper puts forward the design methodof the composition of the graded crushed stone material for the season frozen area, andprovides references for the material design of the graded crushed stone material. The result of this paper both to supplement the vacancy in the design method of gradedcrushed stone in season frozen area, and make contribution to enriching pavement structureforms in our country. Not only put forward good theoretical and practical foundation for theapplication of graded crushed stone in season frozen area, but also provides a reference forusing graded crushed stone in other regions, and this study result has important theoreticaland practical significance.