The Research Of Beam Bridge Under The Action Of Blasting Vibration Dynamic Response Analysis

With the development of economic construction in our country,China's infrastructure construction more and more,the building density increasing,a number of new projects tend to be close to the existing engineering or engineering and has a cross,in the construction of new construction in engineering blasting is difficult to avoid,and blasting safety of the existing projects will produce an important influence.This article unifies the Chongqing city Banan district logistics base three of the southern section longitudinal road construction blasting engineering of road construction site blasting vibration signal analysis field and the corresponding theory,analyze the influence of blasting vibration on adjacent bridge.According to the beam bridge power in blasting vibration response analysis has mainly done the following research:?According to the construction engineering road crossing under the existing bridge,the surrounding mountains require multiple engineering blasting,in the process of blasting project,has carried on the analysis of the repeated blasting vibration test,the test results showed that the frequency of blasting vibration signal rate,frequency of blasting vibration will not produce resonance with the bridge,the trend of vertical vibration velocity the main bearing position to 1/4 from the cross position to cross position is increased,that the vertical velocity of blasting vibration from the beam end to cross on the process of vertical amplification effect.?The blasting vibration signal of bridge girder measured by vibration signal and heavy vehicle were compared,summed up the difference between the two signals and its influence on bridge structure,it was found that the heavy truck through signals than the blasting vibration signal is obviously improved and the overall high frequency,multi peak,heavy truck through vibration energy increases and more dispersed,when explosive less powerful or distance of blasting vibration in blasting vibration is far away,the car through the bridge response of bridge structure is likely to be greater than the response of blasting vibration on bridge structure.?The application of finite element software MIDAS/Civil to establish the finite element model of the bridge structure,the time history analysis method,analysis the transformation rule of the maximum response of the bridge structure under the action of the same triangle wave amplitude values in different duration,found that short triangular wave acceleration curve duration from 0.1s to 0.01 s to 0.001 s bridge of second span peak gradually decreases.The vertical velocity response of girder also decreased gradually.?The triangular wave at the same time the same amplitude,using response spectrum method and time history analysis of the main girder internal force and displacement of each measuring point blasting response,the results of comparative analysis,found that the response of bridge structures internal force and displacement values in the response spectrum analysis and time history analysis results are similar,so in the seismic analysis,the structure can be both design reference checking each other.?The comparative analysis to determine the reliability and safety of the excavation construction blasting vibration monitoring of road excavation construction blasting vibration monitoring results with the national safety standards,provides a beam bridge structure in the construction period of excavation blasting vibration safety control standard.