Simulation Analysis Of The Bilayer Reinforcement CRCP's Temperature Stress Based On ANSYS

Relys on “Wuhan City Highway NO.21 reconstruction project”,based on the field measurement data,a Bilayer Reinforcement CRCP finite element simulation model was constructed to analyze the thermal stress.The field measurement data show that the temperature load stress is much larger than the vehicle load stress,and the temperature stress has significant influence.Under extreme temperature condition,the steel temperature stress can reach more than 50% of its yield strength.This paper first analyzes the temperature warp stress of the Bilayer Reinforcement CRCP from two aspects of the reinforcing bar and the crack.It is found that the higher the reinforcement ratio is,the greater the warping stress is,the influence of the distance between steel bars is greater than the diameter of the steel bar;because the Bilayer Reinforcement CRCP is allowed to work with cracks and the spacing between cracks is relatively dense,the warpage stress is generally small,and the maximum temperature warpage stress is located in the plate width direction;In the case of the same reinforcement ratio,the effect of single and double reinforcement on the warpage stress can be ignored;The larger the crack spacing is,the larger the warpage stress is.When the crack spacing is 0.9m,the finite element model is prone to new crack,which is mostly consistent with the measured crack spacing 0.3-0.9m;The greater the crack width,the less concrete warpage stress;With NOLA temperature area method to separate longitudinal temperature stress,the steel thermal stress accounts for more than 90% of the total stress.Then,according to the existing single-layer CRCP shrinkage stress equilibrium equation to build Bilayer Reinforcement CRCP shrinkage stress balance equation.Comparing the measured law of temperature stress with the law of finite element simulation,the two law agree that the most unfavorable position of the Bilayer Reinforcement CRCP is the longitudinal reinforcement of the cracks in the slab,and the most unfavorable situation is the conclusion of cooling.Finally,the parametric influence analysis is carried out: It is found that the surface modulus is approximately linear with the longitudinal reinforcement stress in the upper and lower layers,and the longitudinal reinforcement stress increases with the increase of the surface layer modulus;Longitudinal reinforcement stress increases with base modulus and thickness;The thickness of subbase,the modulus of subgrade and the friction coefficient have little effect on the thermal stress of longitudinal reinforcement of Bilayer Reinforcement CRCP;With the increase of the average crack spacing,the stress of longitudinal reinforcement obviously increases.When the crack spacing is 1.5m,the stress of the upper longitudinal reinforcement reaches 87.25% of its yield strength when the temperature is reduced by 30 ?;The greater the crack width,the greater the longitudinal reinforcement stress;The higher the reinforcement ratio,the smaller the longitudinal temperature stress of steel reinforcement.In summary,under the condition that the reinforcement ratio is constant and the construction process permits we recommend using small diameter small spacing of the reinforcement.