Studies On Carrying Capacity Of Composite Airfield Pavement Based On Displacement Field In Conditions Of Aircraft Taxing

Composite pavement structure is an effective way to structurally strengthening and functionally recover the airport pavement. The calculation method of the bearing capacity of composite pavement has not been unified now. The PCN values calculated by different calculation method have a big difference. So how to scientifically evaluate bearing capacity of composite pavement relates directly to the safety of airport. The FWD testing technology is used to test the bearing capacity of airport pavement, but the loading efficiency of this technology is not enough and airport need to suspend air service for testing. Therefore evaluating the bearing capacity of composite pavement in conditions of aircraft taxiing has always been a problem urgently to be solved in engineering. This article is completed under supporting of The National Natural Science Funds and National Supercomputing Center. The evaluation method of the bearing capacity of composite pavement, which is based on the equivalent displacement, is established through the means of theoretical analysis and finite element simulation. And then the rapid testing technology of the bearing capacity of composite pavement in conditions of aircraft taxiing is formed. The main research contents and conclusions are as follow:1. Comprehensively considering the influence factors of the aircraft dynamic load including pavement roughness, the aircraft lift and aircraft structural parameters, the analysis model of dynamic factor is established based on the international roughness index IRI and aerodynamic modification, which provides a reference for pavement design and analysis of pavement structure dynamic response.2. The common forms of composite pavement structure are analyzed. The finite element model of composite pavement and calculation area are identified, and the effect of joints and interfacial contact condition on the displacement is analyzed. The influence rule of key parameters and aircraft loads on the pavement displacement field is analyzed by a large number of finite element calculations. The results show that: Resilience modulus of foundation is the main factor to influence displacement on the test area. The distal displacement is almost not affected by other structural parameters except the resilience modulus of foundation.3. The equivalent displacement principle of thickness conversion calculation is determined by studying composite pavement PCN calculation method in the current specification and the influence factors of the bearing capacity of airport pavement. The thickness conversion formulas of composite pavement is regressed by orthogonal experimentdesign and a large number of finite element trial. Finally the influence rule of various factors on the conversion thickness is analyzed. The results show that: The effect of thickness of asphalt concrete on the result of the conversion thickness is the most significant.4. The rapid testing method of the bearing capacity of airport pavement is put forward by studying the theory of foundation strength inversion which based on the displacement and the acquisition and processing technology of displacement signal. The PCN test software is compiled by the Visual Studio 2010. The rapid testing technology of the bearing capacity of composite airport pavement in conditions of aircraft taxiing is systematically put forward,which provides a reference for the practices of engineering testing.