The Reinforcement Research Of The Inservice Rigid-Frame Concreta Arch Bridge

Based on the reinforcement project of Yongfu Bridge, the reinforcement method analysis of the main arch rib, and cross beam and slightly curved board of the bridge is studied in this paper. The result of the static and dynamic test indicates that the bearing capacity and dynamic stability properties of structure have reached the expected effect. The reinforcement method has the advantages of short construction period; transportation is not affect and reasonable cost etc. The main research results are as follows:(1) The method of pasting steel plate is studied according to the characteristics of the main arch rib local cracks. The stress change rule of the main arch rib reinforcement is investigated by finite element software. It shows that the method of pasting steel plate applied on different parts of the main arch rib have obvious different reinforcement effect. Furthermore, different thickness of pasting steel plate has different impact on the strengthening effect at each part, so practical reinforcements should choose the suitable thickness of steel plate.(2) The method of additional payments is studied according to the characteristics of lateral links weak and overall lstiffness low. The change of the dynamic characteristics after reinforced by additional payments method and the damage simulation of cross collar beam joint are researched by ANSYS software. The results show that additional payments method can better improve the dynamic performance of rigid frame arch, its reinforcement effect is inferior to increase cross-section method and is superior to the node steel method. Comprehensive analysis, additional steel reinforcement method is a optimization measure to the reinforcement of arch bridge cross beam.(3) The method of pasting steel plate is studied according to the characteristics of the curved board strength shortage.The stress state of curved board after surface of steel reinforcement is studied by using finite element software basing on the method of Secondary analysis. It showed that surface of steel can effectively improve curved board stress state. Comparing the theoretical value to measured values, it shows that type steel beam and slightly curved plate can form a composite structure, which has a good stress state and excellent performance. Compared with conventional strengthening method, Its overall reinforcement effect between the increase stiffener method and rockbolt concrete reinforcement method. But the stress of the curved board stiffener is opposite bigger by using surface of steel reinforcement method, so anti-cracking measures will be better opposed to curved board stiffener when using the method.(4) The analysis of bridge stability performance after the reinforcement shows that the reinforcement can improve the partial load effect that is the stability performance under the partial load.(5) The analysis of the static test indicates that the stiffness, strength and bearing capacity are meet the requirements, the wholebridge is in the elastic state. The analysis of dynamic test indicates that the reinforcement for whole lateral rigidity enhancement effect is obvious after reinforcement. Also significantly improve the performances of the bridge transverse connection and the structure overall energy dissipation. The method adopted is feasible which have reached the expected effect.This article research results for reinforcement of concrete rigid frame arch bridge in service provides a comparative data reference, also the reinforcement deliver a reference for the similar bridge.