The Finite Element Optimization Analysis Of The Bilayer CRCP’s Reinforcement Stress State Based On Ortogoanl Test

Paper relys on Wuhan Urban Construction Committee’s Item “Under Heavy Load Conditions Bilayer Continuously Reinforced Cement Concrete Pavement’s Design and Techology Study(Item Number:201502)”and “Wuhan City Highway NO.21 reconstruction project”,use the orthogonal test analysis method,the road section test data to ensure the authenticity and reliability of the ANSYS finite element analysis model,study Bilayer Continuously Reinforced Concrete Pavement(CRCP)’s reinforcement stress state.First,the test data shows that Bilayer CRCP’s bottom reinforcement stress is too small,it does not meet the design expectations which the bottom reinforcement is used as the Bilayer CRCP’s main bending members,put forward the idea that structure combination and design parameters may affect the surface layer’s neutral position and lead to irrational reinforcement stress.Then,Combined with different pavement structure model to determine the influencing factors,design orthogonal test,perform finite element calculations,use the orthogonal test analysis to analyze the order of the factors influencing Bilayer CRCP’s bottom reinforcement stress state,the order is that: plain concrete layer thickness>plain concrete modulus> cement stabilized gravel layer thickness> soil base modulus> asphalt layer thickness,on the basis of this,the main influencing factors are analyzed individually by finite element simulation analysis;Finally,according to the above conclusions,put forward the Bilayer CRCP’s reinforcement stress state optimization measures:(1)Without affecting the overall pavement structure,reduce the thickness of the plain concrete layer,and even remove it,the reinforcement stress is greater and the utilization of the steel is higher;(2)The results of the calculation show that the stress of the bottom longitudinal reinforcement is the largest when the cement stabilized gravel layer thickness is 0 cm.Theoretically,the cement stabilized gravel layer can be removed.But considering the possible increase of the reinforcement ratio and structural design rationality,cement stabilized gravel layer thickness should be 15-30 cm;(3)Properly reduce the modulus of the concrete,That is,to reduce the plain concrete layer’s concrete label,in order to improve the reinforcement stress of the pavement structure;(4)Propose the engineering practice optimization program of the “Highway NO.21”: asphalt layer thickness is 4 cm、plain concrete layer thickness is 0 cm、cement stabilized gravel layer thickness is 15 cm、soil base modulus is 45 MPa.