Research On Mechanical Response And Structural Optimization Of Asphalt Pavement With Prefabricated Base Course

Based on the classic fabricated base structure,this paper proposes a new type of base block structure.The arch-like hollow part is filled with benzene board to achieve the advantages of reducing dead weight,heat preservation and heat insulation,strong bearing capacity,high force transmission efficiency,and strong economy.This paper performs finite element calculations on both the classic structure and the optimized structure,analyzes the response law of the classic structure mechanics,and verifies the rationality and many advantages of the optimized structure.The specific contents are as follows:First of all,the finite element calculation is carried out on the classic structure of the prefabricated base asphalt pavement,its load transfer law and bearing capacity are analyzed,and the influence law of multiple factors on the structural mechanics response is explored.This paper calculates under the action of the standard axle load BZZ-100,as the thickness,elastic modulus,Poisson’s ratio and load changes of each structural layer of the subgrade and pavement structure.The parameters such as the maximum tensile stress at the bottom of each structural layer and the maximum displacement of the structure are extracted,and the change rules and internal reasons of each parameter with the change of different variables are analyzed to realize the sensitivity analysis of the parameter change to the static response of the subgrade and pavement structure.Secondly,the crack resistance performance of the classic structure of the prefabricated base asphalt pavement is calculated.From the two aspects of temperatureresistant reflective cracks and load-resistant reflective cracks,the advantages of the fabricated base structure compared with the traditional cement stabilized crushed stone base structure are analyzed,and the mechanical response of the fabricated base with cracks is analyzed.Based on the XFEM module in ABAQUS,a fabricated base course model with prefabricated cracks is established.When there are cracks in the base block and cracks in the mortar,the crack depth,base and mortar elastic modulus,vehicle load and other factors are calculated separately for crack development.Select the stress intensity factor K and J integral to evaluate the crack development law,and calculate its changing trend with the crack depth,elastic modulus and load.Finally,the prefabricated base asphalt pavement structure is optimized.By constructing arch-shaped hollow structure,filling the hollow part with benzene board,eliminating the way of the base layer,to achieve the purpose of reducing the weight of the base block,reducing production and transportation costs,heat preservation and heat insulation,and improving flatness;Establish a finite element model to calculate the mechanical index of the optimized structure under the action of standard axle load,and judge that its structural bearing capacity meets the actual engineering and code requirements;And analyze its advantages over the original structure in terms of load transfer capacity,base layer integrity,thermal insulation performance,anti-reflective cracking ability and economic efficiency;The design and optimization of the base block processing process,the clever connection of the benzene board and the hollow base block,provides convenience for transportation and construction,and provides theoretical support for the base block production.Based on the above content,this paper has carried out the structural mechanics calculation and structural optimization of the prefabricated base asphalt pavement.The research results will have certain reference value for the application and development of prefabricated structures.