Dynamic load test and load lateral distribution of box girder bridge in mining area under special load

Abstract

Dynamic load test of bridge is one of the important indexes to evaluate bridge operation and bearing capacity, however, the test of the lateral distribution of bridge is one of the important means to evaluate the state of bridge. In order to evaluate the stress condition and working performance of a box girder bridge in a mining area under the special load of 100T, dynamic load test and lateral load distribution are studied, dynamic load test is to test the natural vibration frequency damping ratio and impact coefficient of the bridge through pulsating test and traffic running test, the transverse distribution of load is analyzed by deflection method and the experimental value of transverse distribution coefficient is compared with the theoretical value of girder method. The results show that under dynamic load, the first vertical natural vibration frequency of the bridge is 10.986, the damping ratio is 0.015%, and the impact coefficient is 1.07~1.26, the vertical measured fundamental frequency is larger than the calculated fundamental frequency, and the overall stiffness of the bridge meets with the design specification; the transverse connection among the box girders is close and the lateral distribution of load meets with the requirement of the design specification.