Study On Strengthening Scheme And Effect Of Xia Jiang Bridge

The double-curved arch bridge has been widely promoted nationwide in the 1970 s for its beautiful appearance,novel structure,convenient constructionand labor-saving materials.But with the increase of traffic volume and increase of carrying capacity,most double-curvature arch bridges have suffered varying degrees of damage after more than 40 years of service and pose a threat to safe operations.However,in a certain period of time,due to economic considerations and traffic needs,many double-curvature arch bridges will continue to be used.They cannot be completely replaced by new bridges in a short time in such a circumstance.On the premise of ensuring operating safety,it is an effective way to Extend their life span and repair them.This article makes a finite element analysis of the main arch reinforcement method for double-curved arch bridges according to the Xia Jiang Bridge,the main research and achievements are as follows:1)Based on the data from the field survey and on-site inspection of Xia Jiang Bridge,the paper analyzes the causes of diseases,and masters the basic conditions of the bridge and the root causes of the disease.Based on this,the finite element model is established and the force analysis is performed to arrive at a conclusion: reinforcement is necessary.2)From the five common methods used to reinforce the main arch ring of double-curvature arch bridges,I chose three methods that are more suitable for the actual Xia Jiang Bridge method(enlargement cross-section method,paste reinforcement method,change cross-sectional form method)to reinforce the scheme.3)Three sets of reinforcement schemes have been formulated for the three reinforcement methods: the establishment of finite element models,force analysis and deformation calculations,and the mathematical model of the fuzzy comprehensive evaluation method was established to analyze the bearing capacity,the investment amount,the traffic impact,the aesthetic level,the construction period,and the ease of construction.The normalized values of the three reinforcement schemes were 0.35、0.345 and 0.305,that is,the order of the advantages and disadvantages of each program is enlargement cross-section method,paste reinforcement method,change cross-sectional form method.Among them,nlargement cross-section method is the optimal solution.4)A deeper discussion was conducted on the reinforcement method of the enlarged section method,with emphasis on the two important parameters of the reinforcement thickness and the reinforcement range,sensitivity analysis in the finite element model(drafting of two sensitivity analysis methods),and the search for the most Good construction effect.The result of the analysis is that the first method is more comprehensive and regular.The second method focuses on practical applications and it can help to control the most adverse load effects of the structure.At the same time,it shows the difference in the scope of reinforcementand has a large impact on the bridge structure.Therefore,the reinforcement scope selection should be given priority in the reinforcement.For the actual situation of Xia Jiang Bridge,the reinforcement range of L/2should be used for reinforcement,and the reinforcement thickness can be appropriately reduced by 18 cm.5)When reinforcing similar double-curved arch bridges,priority should be given to increasing the section method for reinforcement according to the actual conditions of the bridges.In the design of the reinforcement scheme,the selection of the reinforcement range shall be the key consideration,and the reinforcement thickness shall be adjusted according to the situation.In order to get a more significant reinforcement effect.