Dynamic Analysis And Load Test Study Of High-pier And Long-span PC Continuous Rigid Frame Bridge

Prestressed concrete (PC) continuous rigid frame bridge is widely used in theprocess of bridge construction in our country with its beautiful line, reasonable force,convenient construction, great spanning capacity, and many other advantages. Beforethe bridge structure built need to conduct a comprehensive inspection to assess theperformance of structure, load test plays an important role as one of the most commonlyused method for bridge detection performance.This paper reviews the development of continuous rigid frame and mechanicalcharacteristics firstly, and systematically expounds the related knowledge of bridge testdetection. Based on Xisujiao bridge engineering, build three-dimensional finite elementmodel from engineering reality, combined with the static load test to analyze the internalforces under the bridge lane loads; Based on engineering in side span arrangementpermanent pressure heavy concrete engineering practice, analyzes the pressure of heavyconcrete bridge integrated linear, proposed to the design pressure heavy set degreeincrease the range of appropriate advice.Based on the theory of dynamic characteristics, calculate the feature values andvectors of dynamic equation and the natural vibration modes of the structure using thesubspace iteration method; According to the natural vibration modes and frequencies ofthe project, a detailed analysis of the high pier and long span continuous rigid frame thedynamic characteristics is done, to provide reference for design, construction andoperation of this type of bridge in the future; Using process moving load analysismodule of MIDAS/Civil to define vehicles moving load calendar function,analyzingthe dynamic response of the structure under different speeds, extracting thedisplacement time history data of the midspan nodes under different speeds, thevariation rule between the speed and the dynamic coefficient of continuous rigid framebridge is obtained.Briefly introduces the theory of bridge structural load tests; According to therelated theory and result of finite element analysis, draw up test programs, including testspan, control sections, working conditions and vehicle load carrier cloth, etc., carry outthe test and collect data, derive calibration coefficient by comparison with the calculatedvalues, combined with standardized coefficients by checking the actual carryingcapacity of the bridge is evaluated. Using vehicle load carried on the bridge across to take driving, braking, jumpingtests and pulsating test to test the dynamic properties and dynamic response of thestructure, and comparing with the results of the vertical vibration modes and frequenciesof the finite element model to judge the function of the bridge dynamic characteristics,while calculating the impact factor of the structure and the damping ratio and otherparameters based on dynamic load tests measured data.