Study On Design Indexes And Methods For Asphalt Airport Pavement

Asphalt airport pavement has been adopted widely by many international civil airports for its superior performance, such as flat, skid-resisting, comfortable, damping, suitable construction, short building time and easily maintenance. Based on the data from International Civil Aviation Organization (ICAO) , asphalt pavements are accounted for 60 percent in the 1038 airports of 147 member countries. By contrast with the state of art and the developmental direction of airport construction, there are many problems such as lag of design specification, lack of design theory research and engineering application, and complexity of pavement structure. All the problems have restricted the research and construction of airport pavement in out country. For changing the station and catching up with the international development trend, the asphalt pavement design methods of many countries are collected and the whole design system is proposed for the asphalt airport pavement by distress surveys , data analysis, theory study, discussing and numerical simulation et al. The main contents are as follows:(1) By distress surveys in airport and road asphalt pavement condition, the main distress types and the mechanism of damage are studied systemically. Based on the survey data from some airport pavements at home and abroad, the distress modes that need to be controlled in the pavement design are proposed here.(2) Aiming at the flexible base pavement, the main parameters (including materials, structure, aircraft load and environment) of design indexes and transfer functions are compared and studied. Considering the design characters of our asphalt airport pavement, the design indexes and transfer functions are analyzed and selected reasonably.(3) Aiming at the semi-rigid base pavement, the problems of current design theory are analyzed. Refer to the data from full-scale tests of Guanxi airport of Japan and the research fruits of highway about semi-rigid base pavement, the revised transfer functions of the asphalt layer permanent deformation are proposed and the design indexes system for semi-rigid pavement are set up.(4) The superiority and imperfection of empirical method and mechanistic-empirical method are analyzed in detail. Also, some problems of various design methods and current specifications for asphalt concrete pavement design in our country are discussed. With the developed trends of design system in the world, the new design system of asphalt airport pavement is established. And the design steps and flow-chart are proposed for two typical structures separately.(5) Based on the "subgrade-pavement-aircraft loading" interaction system and FLAC3D software, a 3D numerical analysis model of mechanical responding to multiple-gear aircraft loadings is established for asphalt airport pavement. The mechanical responses of pavement to different structure combinations, material parameters and representative aircraft loadings are analyzed with the three-dimension model. Furthermore, the sensitivity of design parameters is discussed using orthogonal experimental design theory and the key factors in pavement design are selected certainly. The numerical analysis model provides a effective technical means for the building and application of design method.(6) Set the average traffic volume from 2004 to 2006 of the first runway of Pudong international airport as an example, two types of asphalt pavement, asphalt stabilized base and semi-rigid base, are designed using the new method of the paper, current specification method of our country and layered elastic analysis design method of FAA. Through comparing the design results computed by the three different methods, the characters and practicability of the three design methods are discussed firstly.Through the course of collection, analysis, reference and improvement of the relevant research work, the dissertation begins an attempt to establish the design method system for the semi-rigid base pavement Based on the advanced design frame, the design theory system is improved and a design method for the modern airport is set up. So, the dissertation establishes a new design frame that follow the international level for the design system of asphalt airport pavement in our country.