Analysis Of The Impact Effect Of The Different Sections Of The Bridge Subjected To Auto Load

With the rapid development of our country′s bridge enterprise,and the constant improvement of the traffic flow magnitude,driving speed and vehicle load, decide need to constantly improve the requirement of bridge structure design,while the impact coefficient as a main index to evaluate the driving performance and bridge deck flatness which researchers have paid more and more attention to.There are calculation method of impact coefficient in our country′s 04 norms, especially that the impact coefficient of continuous girder bridge′s fulcrum negative bending moment of test section con′t calculate with the instructions′s fundamental frequency.Based on the specification,this article includea the collection of a large number of conventional continuous girder bridge and the test samples of arch bridge,according to the method of numerical simulation and analysis of test sample statistic, statistic and analysis the impact coefficient or strain increases coefficient and structural frequency of the test section:the continuous girder bridge side span the fulcrum of the maxium positive bending moment test section and negative bending moment test section,the arch bridge′s L/4 test moment and test moment in the middle.Fitting and analysis of the test section of the mathematical model curves of the relationship between the test section′s coefficient or strain coefficient and the structural frequency,relation curve between optimal. According to the specification values impact effect of significance and reliability to obtain the estimate formula of 95%.Respectively using ABAQUS finite element software to establish the analysis models of Pingchang County Star Industrial Park infrastructure project of 2x30 m small prestressed concrete box girder bridge and Ba River bridge,analysis the natural vibration of frequency of two bridge′s theoretical calculated values,compares and analysis it with the measured value,combined with the actual static load test respectively,verify that the two bridge stiffness.Established the two bridges′s vehicle-bridge coupling model according to the test speed and the test vehicle load.Calculated theoretically by two bridge testing section of impact coefficient or strain coefficient under the different speed.Analysis the theoretical value and the measured values,the standard value and estimated formula value according to the test speed.Verifyed the rationality of the estimate formula curve of the two bridges and evaluated its dynamic performance of the structure.