Prediction Of Residual Life Of In-service Beam Bridges In Dry And Cold Regions Of Northwest China

As an important infrastructure for the modernization of our country,bridges are an important hub in the transportation engineering.After being built into service,they have been affected by the external factors such as environment,load and so on.In addition,the defects are definitely produced in the design and construction process.These factors inevitably lead to the deterioration of bridge performance,the aggravation of structural damage,the reduction of service life,and even more serious accidents such as collapse,which will affect the traffic and endanger the lives of the people.In the dry and cold regions of northwest China,The harsh climates such as dryness,coldness,strong radiation and strong wind and sand have further aggravated the occurrence of bridge diseases,making the actual service life often much shorter than the design service life,especially for concrete beam bridges.Therefore,it is necessary to reasonably predict the residual service life of the beam bridges.In this paper,the residual life prediction of the beam bridge due to structural damage caused by the degradation of the reliability can be studied,firstly,the related theory of the beam bridges' residual life and the reliability correlation theory are discussed,and its prediction methods are analyzed and compared.The applicability of the gray correlation analysis method to the residual life prediction of the beam bridge is comprehensively analyzed and the method is discussed in detail.Secondly,taking the concrete beam bridges in the dry and cold regions of northwest China as the research objects,242 typical highway bridges in Gansu and Qinghai were selected for diseases analysis and statistics,and the goodness-of-fit test was carried out by using the method of moments estimator and D'Agostino test method.Finally,the probability distribution of the main diseases in the dry and cold regions of northwest is determined,which indicates that the diseases degree of beam bridges in this area is approximately normal distribution.Then based on the degradation of the reliability of concrete structures,the common diseases of beam bridges caused by the damage of steel bars and the deterioration of concrete are analyzed.Based on the special diseases and reliability indicators,the index system of residual life prediction of beam bridges in the dry and cold regions of northwest is constructed,and the quantitative methods of prediction indicators are analyzed and compared.The prediction indicators are divided into the degree index and the speed index.And according to the relevant standards and regulations,the reference standard of the residual life indicators of the in-service beam bridges in the dry and cold areas of northwest China is determined.Thirdly,the residual life prediction model of the in-service beam bridges based on the G2 method,anti-entropy weight method and gray correlation degree is established,the correlation coefficient matrix is constructed by the measured index data,the G2 method and the anti-entropy weight method are selected to calculate the combined weight of the beam bridges,and the correlation degree between the actual index set and the optimal index set of the beam bridges is comprehensively obtained,that is,the deterioration degree and the deterioration speed of the beam bridges,and then the structural deterioration coefficient and the deterioration index are obtained,and the residual service life of the beam bridges is obtained by substituting the formula.Finally,by means of the example,the feasibility of the method is proved,not only can the final service life of the beam bridge be calculated,but also the damage condition of the component can be judged,and the most unfavorable position can be obtained for reinforcement and maintenance,ensuring the normal use of the beam bridges and prolonging its service life.Therefore,the life prediction of concrete beam bridges in dry and cold areas of northwest China can not only guide the highway management department to carry out timely maintenance and reinforcement of the existing bridges,but also save the bridge construction funds and resources,And it is conducive to the reasonable planning of traffic and the overall arrangement of funds to ensure the safety and smooth flow of the road network system.