Statistical Analysis And Research Of Impact Coefficient Of Highway Bridge

The dynamic response of the bridge structure under in running vehicle is one of the important parts of the bridge dynamics research,the deformation and stress of bridge structure in moving vehicle loads is greater than static load.Along with rapid development of our country's economy and transportation,vehicles quantity and load has improved tremendously, impact response of bridge in overloaded, high-speed running vehicle has more and more attentions of bridge researchers.Bridge impact coefficient is one of key parameter of the structure dynamic response.This paper focus on two research methods:test sample statistic analysis and numerical simulation, after in a large collection of test sample, do the impact coefficient or strain increases coefficient statistics analysis of simply-supported and continuous girder and arch bridge, and using finite element software to build model to analysis dynamic characteristics.Using collected lots of simply supported and continuous girder bridge,arch bridges dynamic test report,sort out each bridge's measured frequency,impact coefficient or strain increases coefficient and the damping ratio. By analysising above measured data get the relationship between actual impact coefficient of and speed/ basic frequency . Using the statistical software, after choosing various mathematical model and then established function of the measured the fundamental frequency - impact coefficient of girder and arch bridge, and contrast the value of function and a bridge's measured values,whose effectiveness is verified.Using finite element software, established Luoyan bridge -vehicle coupling dynamic model, calculated under different speeds,compared theoretical impact coefficient and measured stress increase coefficient.Change the free vibration frequency of vehicle model to bridge second-order vibration frequency,contrast before and after value of theory impact coefficient in order to verify the bridge-vehicle coupling effects on amplifying function. Contrast theoretical impact coefficient, modal parameters of the element calculations with measured value in order to evaluation Luoyan bridge structure safety performance.