| More than 90 percent of Chinese airport runways are made of cement concrete.However,a lot of damage will happen to the runway before it reaches the designed service life.One of the reasons for the damage in advance is that the bearing capacity of the runway is mainly considered in the design of the runway,while the position of aircraft wheel load is ignored.At present,the most commonly used cement concrete slabs,a width of 4.5 m or 5 m,can not well meet the requirements of the aircraft’s main landing gear passing through the middle of the slab.Moreover,the lateral deviation occurs when the aircraft is taxiing on the plane surface,so that the wheel load of the aircraft will act more on the plate seam,and the plate seam of the smallsize channel panel will be more.It is easy to appear such diseases as broken edges and corners,wrong platform and subsidence,which will affect the comfort and safety of aircraft taxiing on the pavement.In order to reduce the occurrence of cement concrete pavement damage and extend the expected service life of pavement,this paper adopts the method of combining theoretical analysis and finite element software numerical simulation,and combined with the airport example,to study the cement concrete pavement panel zoning of airport runway.The change rules of plate edge stress reduction,temperature stress in plate,displacement field and service life of pavement are analyzed when different pavement partitions are adopted.The main research contents and conclusions are as follows:1.The variation law of the edge stress reduction under the influence of pavement structural parameters and joint stiffness was explored.Through orthogonal test,it was found that the thickness of pavement and the modulus of soil foundation had the most significant effect on the edge stress reduction.According to the classification of joint load transfer capacity,the range of plate edge stress reduction coefficient is established and the recommended value is given.2.Analyze the composition of the internal stress of the panel and conduct the sensitivity analysis of the temperature stress in the panel.The results show that the width and thickness of the channel plate have significant effects on the temperature stress in the plate.The stress in the slab caused by aircraft load almost does not change with the change of the slab size.3.Establish a full-width full-scale solid model of the runway of 45 m,and study the pavement displacement response law under different pavement zoning forms.It is found that the overall property of the large size channel panel is stronger,and when the large size channel panel is used or the size of channel panel can better satisfy the wheel load passing through the plate,the deflection of the channel surface is smaller.4.The influence of pavement slab zoning on the service life of pavement is studied,and the necessity of adding pavement zoning design in the design process of cement concrete pavement is discussed.The research results show that selecting the appropriate size of the pavement can effectively increase the expected service life of the cement concrete pavement.The calculation formula and design process of the slab width for the zoning design of the pavement slab are proposed,and the section design of the pavement slab for an airport runway extension. |
