The Research On New Prefabricated Airport Runway Structure

Due to the advantages of bearing capacity,economy and durability,cement concrete pavement is the main structural form of the runway of civil aviation airport in China,accounting for about 86%.However,cement concrete pavement also has some shortcomings such as difficulty in reinforcing and long time needed for repair.With the rapid growth of airport flight business volume,the increase of service time and the influence of environmental factors,many airport cement concrete pavement diseases have appeared and need to be repaired,but it is difficult to achieve due to the limitation of turnaround time.In order to solve the problem of rapid construction and repair of cement concrete pavement,the precast pavement panel and assembly technology will be the future development direction.Based on the above background,the main research and achievements of this paper are as follows:Firstly,the research on size of precast airfield pavement plate is carried out.Through finite element simulation and theoretical calculation,when the length and width of the precast pavement are changed,the mechanical response of the precast pavement structure under different aircraft loads and temperatures is studied,and the hoisting force of the precast pavement plate is analyzed.Considering the universality of the precast pavement plate used in airport construction,reconstruction,expansion and partial repair,it is suggested that the reasonable plane size of the precast pavement plate should be 5m long ×2.5m wide.Secondly,the research on the problem of support and leveling of precast pavement panel is carried out.By finite element simulation,the influence of non-uniform support on the bearing capacity of precast pavement plate without stress buffer layer is analyzed,and the necessity of adding stress buffer layer between precast pavement and base is obtained.The results show that there are three main parameters that affect the bearing capacity of the precast pavement,namely,the thickness of the precast slab,the thickness of the stress buffer layer and the elastic modulus of the stress buffer layer.On this basis,taking the common civil aviation B737-800 as an example,the values of the above three main parameters of the precast pavement are optimized and analyzed.In order to ensure the mechanical properties and service performance of the pavement structure under the action of B737-800 aircraft,the thickness of the precast pavement plate should not be less than 34 cm,the thickness of the stress buffer layer should be 2cm～4cm,and the elastic modulus of the stress buffer layer should be 1200MPa～1500MPa.In order to solve the leveling problem of precast panel,an integrated leveling and hoisting device was proposed.Thirdly,the research on the force transfer mechanism of prefabricated channel panel is carried out.Three new types of force transmission mechanisms,namely,gear propulsion force transmission mechanism,upper opening force transmission mechanism and lower opening force transmission mechanism,are put forward.Through finite element simulation,the influence of three main parameters,such as the diameter,distance and length of the transmission rod,on the load transfer performance and mechanical performance of the new precast pavement structure is analyzed,and it is concluded that there is serious stress concentration in the contact interface between the transmission rod and concrete.For the prefabricated pavement with a thickness of 38 cm,in order to make the interface stress between the force transmission rod and concrete not exceed the allowable supporting stress,it is suggested to adopt the layout method of 35 mm in diameter,300 mm in spacing and 500 mm in length to conduct joint treatment between the precast plates.