Time-varying Effect Analysis Of Reinforced Concrete Arch Bridge Strengthened By Hoop Technique

For the reinforced concrete arch bridge strengthened by hoop technique,the shrinkage and creep of concrete will cause the structural displacement to change with time and cause stress redistribution.In view of the fact that there are few researches on the time-varying effect of hoop reinforcement structure at home and abroad.This paper mainly uses the finite element software ANSYS to analyze the influence on the reinforcement structure for concrete shrinkage and creep.The main contents are as follows:1.Based on the collection of existing achievements,the research status and calculation theory of hoop reinforcement technology and concrete shrinkage and creep are summarized.2.Through the ANSYS to achieve concrete shrinkage,creep and the relationship between old and new concrete.Based on the Ansys secondary development tool,according to the concrete creep expression provided by China’s specifications,by modifying the user subroutine USERCR.F in ANSYS and use the effective modulus method based on age adjustment to realize the creep effect of concrete;The method of temperature reduction simulates the shrinkage effect of concrete;ANSYS contact analysis is used to simulate the relationship between new and old concrete.According to the numerical simulation and the research results,it is feasible to use the above method to realize the concrete shrinkage and creep and the relationship between old and new concrete in ANSYS.3.According to the hoop reinforcement reinforced concrete arch rib model specimens,the effects of concrete shrinkage and creep on the displacement,stress and strain of the reinforced structure are analyzed.The results show that the concrete shrinkage will cause the core concrete to be compressed,and the new concrete will be pulled;the creep of the concrete will lead to the stress redistribution,the stress of the core concrete will increase,and the stress of the new concrete will decrease;The secondary development method to calculate the concrete creep effect is higher than the effective modulus method based on age adjustment.Using ANSYS secondary development to calculate concrete creep is conservative,but the structural design is safe.4.The effects of initial stress of core concrete,concrete strength,thickness of hoop layer concrete and reinforcement ratio on the shrinkage and creep of the hoop reinforcement structure are analyzed.