Research on Graded Broken Stone Design Standard and Design Method Based on Vibrating Compaction
|Course||Road and Railway Engineering|
|Keywords||Graded broken stone Vibration test method multi-level dense built-in gradation Design modulus Design standard Design method|
Graded broken stone is widely used as highway pavement base and subbase layers material abroad, but seldom used in highway base layer construction in our country. This is mainly because of the deficiency of study on graded broken stone physical and mechanical property. Previous researches on graded broken stone take the means of heavy compacting and static pressing to make speciments, which are not consistent with the actual vibrating compacted graded broken stone base, and the result can’t reveal the essential physical and mechanical property of graded broken stone. So, on basis of sufficient discussion on the simulating effect of vibration test method, the paper studies on the relationship between graded broken stone composition structure and its physical and mechanical property, as well as the strength design standard and material design method, which is of great practical significance.The paper first analyzes the principle of vibration test method, and verifies its simulation effect; on the basis of interference theory, the paper takes the stage filling test to determine the coarse aggregate gradation, and then takes test to decide the fine aggregate gradation by i method and maximum-strength principle. Then, takes five different coarse aggregate to fine aggregate ratios to optimize the gradations by the physical and mechanical property index; studies on the graded broken stone physical and mechnical property influencing law; calculates and analyzes maximum shear stress in the asphalt pavement with graded broken stone plus semi-rigid base and graded broken stone flexible base, as well as its effect on pavement design indexes, and then proposes graded broken stone design standard and design modulus; above all, a graded broken stone design method based on vibration test method is built in this paper. The study is stimulative for the promotion and development of graded broken stone.