Study On Reinforce Scheme Optimization Of Continuous Rigid Frame Bridge In Dry And Cold Regions Of Northwest China

With the continuous development and improvement of the highway transportation network,the increase of traffic density and large-scale trucks,many highway bridges are seriously deteriorated in the design life cycle,and the reliability requirements of bridges are seriously inadequate.In the early years,lower construction standards and the lack of maintenance awareness also exacerbated the deterioration of bridge diseases.At the same time,in the face of the contradiction between the development demand of the highway transportation industry and the maintenance,reinforcement and transformation of the old and dangerous bridges,the severe natural environment in the northwest,the backward economic situation in the more developed areas,and the large number of old and dangerous bridges make it become more prominent to use the limited funds to reasonably make the decision of the old bridge reinforcement scheme,to maximize the economic service life,and to guarantee the highway construction to be developed in sustainable ways.Therefore,it is of great social significance and practical value to select the most satisfactory reinforcement scheme from many feasible schemes.Taking the continuous rigid frame bridge in the dry and cold area of Northwest China as the research object,this paper analyzes the disease mechanism of the typical and general diseases of the continuous rigid frame bridge in detail,summarizes the reinforcement mechanism,technical characteristics and applicable scope of each practical reinforcement technology,analyzes the relevant theories and methods of multi-attribute decision-making,and provides the theoretical basis for the optimization model of the bridge reinforcement scheme.Scientific and reasonable index system is the basis of correct decision-making.Based on literature review and specification reference,the evaluation indexes affecting the optimization of reinforcement scheme of continuous rigid frame bridge are preliminarily selected.Based on the index importance questionnaire and the principal component analysis method of information sensitivity,the index system of bridge plus scheme optimization is finally established,which includes 16 indexes of reliability of reinforcement effect,economic rationality and feasibility of construction technology.Through the analysis and quantification of the indexes,the optimization index system of the reinforcement scheme of the continuous rigid frame bridge suitable for the dry and cold area of Northwest China has been established.In view of the uncertainty in the process of strengthening scheme optimization of continuous rigid frame bridge,a scientific and reasonable index comprehensive weight is determined based on the combination weighting of game theory.Combining with the bridge diseases in the dry and cold area of Northwest China,taking the plan to be evaluated as the identification framework,taking the established index system as the evidence body,using the gray correlation method to determine the reliability of each evidence body,using the D-S evidence theory fusion rules,and finally ranking the plans by the reliability function value.The results show that the model has good applicability in the optimization of bridge reinforcement scheme,the comparison results are reliable and reasonable,and greatly improves the accuracy of decision-making and the distinction between schemes.This study is helpful to solve the problem of unscientific selection of strengthening scheme caused by the fuzzy index and high uncertainty between schemes in the optimization of strengthening scheme of continuous rigid frame bridge in the dry and cold area of Northwest China.It is helpful to improve the accuracy and differentiation of scheme decision-making,and to determine the most satisfactory scheme more scientifically and reasonably.Moreover,it has broad application prospects for effectively improving the service life of bridge reinforcement and sustainable development of bridge construction.