Test And Numerical Analysis Of Load Limit Value Of Prestressed Concrete Hollow Slab Bridge

In recent years,with the improvement of my country’s economic level and the development of transportation,heavy-duty trucks have become the main means of transportation,which poses a great threat to the safety of bridge structures,and also brings great pressure to bridge operation and management.In order to ensure the safety of the actual operation of the bridge structure,it is urgent to carry out the theoretical research work of the bridge load limit system.This paper is based on the theory of structural reliability,based on a prestressed concrete hollow slab bridge,based on the bridge load limit analysis method proposed by the research team,and combined with the static load test of the bridge,to carry out load limit value research on the bridge.The main research contents are as follows:(1)This paper introduces the overload transportation situation of bridges at home and abroad,expounds the significance of the research on the load limit of bridges,and summarizes the current situation and achievements of the research on the load limit of bridges at home and abroad in recent years.(2)This paper systematically introduces the bridge load limit analysis method based on structural reliability theory for medium and small span bridges.This load limit analysis method is also the theoretical basis for the research on load limit value in this paper.(3)Taking a prestressed concrete hollow slab bridge as the research object,the 10th span of the East approach bridge is selected for load limit analysis.According to the bridge design data,the resistance standard value,dead load effect and vehicle load effect under different transverse load distribution modes of the bridge are calculated in detail,and then the resistance correction coefficient of the bridge is determined,and the load limit coefficient and load limit value under the design safety level I are calculated by the interpolation of the resistance correction coefficient and the ratio of live and dead load.(4)Using the large-scale finite element software MIDAS/Civil,the structural model of the 10th span bridge of the east approach bridge was established,and the static load test was carried out on the bridge.Based on the static load test data,the initial finite element model was modified to reflect the bridge.The basic finite element model of the actual stress condition,and then the modified finite element model is used to calculate the deflection,stress and fulcrum shear of the bridge under the action of the load-limiting vehicle,and the bridge is verified from the normal service limit state and the load capacity limit state Engineering adaptability of load limit value.