Dynamic Analysis Of Reinforced Concrete T And Box Girder Bridge Subjected To Blast Load

In recent years,many accidental explosion have occurred on the bridge structure,causing the destruction of the bridge,which seriously threatens people 's life,the safety problem of bridge has aroused widespread concern when it is subjected to explosive loading.Therefore,scholars at home and abroad have studied the antiknock performance of the bridge.The problem which is the dynamic response of reinforced concrete bridge structures under blast loading is the primary task to study the Anti-explosion performance of bridge structures.This paper uses the method of the combination of model test and numerical simulation to analyze the problems of the dynamic response and damage of reinforced concrete T-beam bridges and box girder bridges under blast loading.The main contents and conclusions are as follows:Sum up the existing research results and existing problems of bridge structures under blast explosive loads at home and abroad,summarize the propagation mechanism of blast wave and the damage mechanism of bridge structure.The dynamic response of reinforced concrete T-beam bridges and box-girder bridges under different explosion conditions(dose amount,initiation height,and explosion source location)is experimentally studied,based on the strain and acceleration data collected during the test,analyze the response effects and laws of T beams and box girders,the results show that the transverse tension(strain)on the wing is larger than the longitudinal tension(strain),and the transverse tension(strain)on the web is less than the longitudinal tension(strain).The acceleration of the wing plate is greater than the acceleration of the web,indicating that the wing plate is more prone to damage than the web.The comparison of T beam and box girder shows that the box girder has better anti detonation resistance subject to blast load.The large-scale finite element software ABAQUS is used to simulate the dynamic response of reinforced concrete T-beams and box girders under blast loading and then it's results are compared with the experimental results.The study shows that the vertical area closest to the blast source under the blast load and flange edge and web floor bottom at transverse section where the source location is located are most likely to be damaged under the blast loading.The active monitoring technology of piezoelectric smart aggregate is used to monitor the damage of the bridge model under the explosive load.The results show that the damage of the wing plate is more obvious than that of the web.Therefore,the wing plate is more prone to damage.This method can accurately reflect the internal damage of the wing plate and web of the bridge,which is of certain significance for the study of the damage degree of the model.