Comparative Study On Safety Evaluation Indices Of Highway Bridges Between China And America

Bridge is an important part of highway traffic,its safety is directly related to the patency of highways,and the importance of bridge safety is getting more and more extensive social attention.For most of the bridges that have been built,with the increase of operation time and the increasing of traffic volume,the performance of bridge structure is gradually degraded.Many bridge structures have disease,breakage,even serious traffic accidents,and the safety problems of highway bridges should not be neglected.Based on the contents of the bridge safety assessment between China and America,this paper introduces the development of the highway bridge between China and America,and compares the bridge's appearance detection and bearing capacity evaluation respectively.In the aspect of appearance detection,the paper mainly compares the classification of detection types between the two countries,the classification of assessment types,the description of rating grade and the content of bridge technical condition evaluation algorithm.To summarize the differences in appearance detection between them.In the evaluation of bearing capacity,the differences and similarities between the two countries'norms are analyzed and compared according to the calculation formula,evaluation criteria,evaluation process,coefficient value and vehicle load value of the two countries in the concrete bridge.Combined with a bridge specimen,the technical status of the bridge is evaluated by using the two-state evaluation method through the content of the appearance inspection.Through the data of the appearance test,the actual state model of the bridge is established,the calculation of the bridge bearing capacity is calculated by using the evaluation formula of bridge bearing capacity,and then the verification of the load test of the bridge is carried out to illustrate the accuracy of the comparison result.The analysis and comparison show that the content of bridge inspection and the evaluation method of bridge states are basically consistent between China and America.The contents of bridge inspection are more extensive in American Standard,and the evaluation of bridge technical condition is more comprehensive.Bridge bearing capacity of the United States and China are basically the conform.Only in the parameters of the Chinese Specification is through the appearance of data to determine,while the U.S.Standard coefficient includes the value of both the appearance also the fixed value selection.Through the actual calculation of the sample bridge,the results obtained by the two countries in the inspection of appearance and bearing capacity are basically consistent,and the correctness of the tests is verified by the load test.