Rutting Contral For Aspalt Pavements With Flexible Base Of Airport Based On Mix Traffic Analysis

Along with the presence of the new generation large aircraft (NGLA) such as B-777 and A380 etc. , the future airport asphalt concrete pavement should satisfy the special requirement caused by heavier load, wider coverage area, more tires, higher tire pressure of NGLA. The advanced airport pavement design method has changed to mechanics-empirical method from empirical method in order to satisfy the requirements of New Generation Large Aircraft (NGLA).The key to constructing mechanics-empirical method is the correlation between aircraft loads, pavement structures, design criteria and operational performances. According to the investigation result at home and abroad, rutting is one of the major distresses found in airport asphalt pavement. Therefore, rutting model corresponding to the rutting failure is an important part of the foundation of mechanics-empirical method.Rutting models in airport pavements and highway design methods are studied. The performance and the mechanics response in airport and highway pavements structure are compared. After studying the rutting models in airport carefully, the rutting criteria aiming at NGLA is proposed and the applicable range of these models are pointed out. The former rutting models based on MWHGL test are not suitable for NGLA such as B-777 and A380 etc. It is necessary to found a new rutting model for NGLA based on the full-scale test data which have covered the load range and the new types of landing gears of NGLA.Mix traffic analyses at home and abroad are summarized, and the frame of the rutting prediction model based on cumulative damage theory is proposed. All kinds of aircrafts are divided into two types, that's, the ordinary aircrafts and NGLA. And each type will use respective rutting model. The prediction model based on cumulative damage theory represent critical state of rutting distress.Full-scale test data of NAPTF are collected to establish rutting model for NGLA. Then the model is combined with the frame of the prediction model based on cumulative damage theory, thus, the prediction model for asphalt pavements with flexible base of airport is established successfully. In the prediction model, all kinds of aircrafts are divided into two types, that is, the ordinary type and NGLA. The rutting model in LEDFAA1.2 is adopted for the ordinary type, and the rutting model based on NAPTF test data is adopted for NGLA. This prediction model could be used to design pavement structure due to rutting failure.According to the research results above, design flow of mechanics-empirical method based on cumulative damage theory is established. The average annual traffic volume of Pudong airport between 2004 to 2006 is selected. The pavement structure is trial calculated repeatedly until achieving the final result. Finally, with considering the feasibility of constructions, a gravel base asphalt pavement structure and a asphalt stabilized base asphalt pavement structure are proposed.