Load Transfer Performance Of Cement Concrete Pavement Joints Based On Finite Element Analysis

Cement concrete pavement has many advantages such as high strength,large stiffness,high stability and good durability.In order to reduce the impact of expansion stress and warpage stress of cement concrete pavement panel and avoid more irregular cracks in the pavement,cement concrete pavement needs to set many joints.Joint is an extremely important part of the pavement panel,but also the weakest and most vulnerable to breakage of the pavement panel,damage to the joints will directly lead to the decline in road performance and accelerate the destruction of the pavement slab.Therefore,the joint performance has a significant impact on the stress,load transfer performance,road performance and service life of cement concrete panels.In this thesis,through extensive data research and analysis,a systematic study on the mechanism of load transferring action of cement concrete pavement joints and the load transferring capacity of joints is conducted through finite element simulation based on a review of the research on the structural mechanical response of cement concrete pavements.The main research contents are as follows.First,it is introduced the structure of cement concrete pavement and the design requirements of joints in this thesis,then analyzes the damage forms and damage mechanisms of pavement panels,and then gives a brief description of several forms of joints and the mechanical behavior of joints.Then,based on a brief introduction of finite element theory,a three-dimensional finite element model of the cement concrete pavement panel is established,and the simplification of the pavement structure,structural cells,mesh division,boundary constraints,vehicle loads and load loading locations are explained in detail.The virtual material layer method and spring cell method were used to simulate the joint load transfer under different working conditions,including concrete slab thickness,base layer stiffness,joint width,joint stiffness,interlayer contact state,heavy overload and slab bottom debonding as the research indexes,to find the joint load transfer law and the change of stress in the slab.Finally,by analyzing the finite element simulation results,the influence law of various parameters on the joint load transfer performance of cement concrete pavement is analyzed and studied,and the following conclusions are obtained: the joint load transfer capacity increases with the increase of concrete slab thickness,base layer stiffness and joint stiffness,decreases with the increase of joint width and bottom debonding degree,and does not change significantly with the increase of interlayer friction coefficient and wheel load;the maximum tensile stress at the bottom of the loaded slab increases with the increase of the maximum tensile stress at the bottom of the loaded slab.The maximum tensile stress at the bottom of the loaded slab decreases with the increase of concrete slab thickness,base layer stiffness,joint stiffness and interlayer friction coefficient,and increases with the increase of joint width,wheel load and bottom of slab debonding.The above research can provide some reference for future joint design,reducing the incidence of pavement distress and reducing road maintenance time and costs.