| Nowadays,tens of thousands of old bridge due to bad operating environment that is the increase in traffic and load,the low standard of original design load,the insufficient in carrying capacity,the not enough in width and accelerated ageing,reduce the carrying capacity,has become the bottleneck on the highway which is continuously improving technology level.If all bridges that can not adapt to the modern transportation are demolition reconstructed,money not only costly,and time is not allowed.Therefore,we need to continuously strengthen the maintenance,reinforcement and retrofit of the existing bridge,restore its bearing capacity or improve load standard,and prolong its service life to safeguard the sustainable development of highway construction.In the arid and cold region of North-West China,because of the bad climate environment and relatively backward economic level,the problem of highway bridge is more serious and urgent.Based on this,the author analysis the optimization of dry cold northwest bridge reinforcement plan in this paper,the main contents are as follows:After detailed analysising the existing data of 798 bridges on Lianhuo High-speed(G30)Gulang-Guazhou section,the author summarizes the most common diseases and their causes in the arid and cold region of North-West China,puts forward some countermeasures for strengthening against disease,systematic analysis the characteristics and applicability of bridge upper structure’s common reinforcement methods.This provides strong reference for the selection of bridge reinforcement method in the reinforcement.By reference to specification,investigation and literature,the author puts forward the bridge reinforcement scheme optimization index system of the arid and cold region of North-West China,and then filtered them by mathematical method and Delphi method to form the final secondary reinforcement scheme optimization index system,contains three first-level indicators and 19 secondary indicators;The author explains the meaning of each index and detailed lists ten calculation formula of quantitative indicators;The author lists the quantitative index of uniform approach and qualitative indexes of dimensionless method.Using the way of maximizing deviations to combine subjective AHP weights and objective entropy weight,the author determines the bridge reinforcement scheme optimization index weights in the arid and cold region of North 一 West China;After the analysis of the principle and using range of many decision-making methods,the author selects the TOPSIS method which is most suitable for scheme selection,and puts forward the improved TOPSIS method which is based on vertical distance according to the defects of traditional TOPSIS method;The author builds bridge reinforcement plan optimization model in the arid and cold region of North-West China based on combination of empowerment-improved TOPSIS method and provides a new train of thought and method to choose reinforcing scheme that meets the requirements of social,technical and economical.For the reinforcement example of Jiayuguan K2378 + 466 003 bridge in Lianhuo high-speed(G30)the Gulang-Guazhou-melon section,the author uses the model that is based on combination of empowerment-improved TOPSIS method to optimize scheme of four kinds of reinforcement and the result is pasting CFRP strengthening method which is coincided with the practical.Considering the advantage that pasting CFRP can highly improve concrete’s crack resistance,this fully shows that the reinforcement plan optimization model is effective and reasonable.In this paper,the bridge reinforcement technique and optimization theory is applied to the arid and cold region of North-West China,aims to build the bridge reinforcement plan optimization model.On the one hand,the author wants to enrich the reinforcement plan optimization method of existing bridge,on the other hand to provide decision basis for bridge management.This paper has extensive engineering application prospects and great economic benefits. |
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