The Research Of Rapid Diagnosis Technology Based On Multi-order Frequency Bridge

The traditional bridge static load test method has a complex testing process,long test cycles,and usually requires interruption of traffic,affecting the normal operation of traffic.Therefore,how to quickly and effectively determine the mechanical properties of the bridge has important practical significance.Some research work have been done to derive the calculation model of bridge displacement coefficient using the dynamic testing analysis method under additional load based on multi-order frequency,so as to provide a new bridge structure dynamic detection method.Firstly,based on finite element theory of reinforced concrete,using the finite element analysis software,establish finite element models of reinforced concrete bridge with good condition and different damage levels,analysising the static and dynamic calculation data with defferent attached load,propoing a new calculation model of bridge displacement coefficient using the dynamic testing analysis method under attached load based on multi-order frequency.Secondly,the research is based on models beam of reinforced concrete with static and dynamic load test,calculating the deflection calibration coefficient? by analyzing static load deflection under different attached loads;calculating the square of the ratio formula K_f²=?f₁/f?² of theory frequency and measured frequency by analyzing multi-order frequency under different attached loads.The consistency of the final data result indicate that the theoretical analysis is correct and that the dynamic testing method under attached load replace the static testing method is feasible.Finally,the research is based on reinforced concrete bridge test examples with static and dynamic load test under different attached loads.The test data showed that two methods arrive at a consistent assessment results,which prove that The dynamic testing method under attached loads has important practical value in Bridge detection.