The Research On The Performance Of The Joint Of The Middle And Small Simple Supported Beam Bridge Under The Action Of Vehicle Impact

The research on the influence of vehicle for dynamic effect on bridge structure has traditionally been the hot topic,but more is for railway bridge and highway bridge in the study area is relatively less in recent years.With the country investment in road transport industry vigorously in recent years,transportation focus is partial to road traffic.As an important link in the highway transportation,bridge structure is bound to undertake more and more transportation task,inevitably faced a lot of heavy vehicle impact,especially the small and medium-sized bridge structure which accounts for the largest proportion of the number,the stress situation is also not optimistic.It is common that bridge vibration damage caused by vehicle impact happens.Vibration problem caused by the vehicle is more focused on the research of bridge's overall response,the reality is that the bridge structure damage is caused by the destruction of the local components.Hollow slab bridge,which is used commonly as a kind of small and medium span Bridges,the local component hinge joints have appeared different degree of damage.In this paper,the research of the influence of the vehicle is taken from the the force situation of the hinge joints.During the design period of hollow slab bridge,for automobile impact force calculation,we have considered the impact by the impact coefficient,but the reality is that during the bridge service process vibration damage caused by the impact occurs frequently,this means that the impact coefficient adopted in the design is too small,so the calculation of the vehicle impact and the actual situation does not match,this is because we did not take the influence of the surface roughness of bridge deck into account during the operation of the bridge in the process.In this paper,we introduce the concept of coefficient of the road situation,it is a parameters related to bridge deck roughness,the coefficient of different grades of road traffic is also different,for different levels of surface roughness of bridge deck,the impact force produced by the vehicles is also not the same,through the simulation of bridge deck roughness in bridge longitudinal changes and dynamic load caused by vehicle when it is passing the bridge at a certain speed,then we can consider the dynamic load coefficient as the coefficient of the road situation.So in the process of modeling,the calculation of impact force should be taken in the way that vehicle load multiply the impact coefficient from the standard value,then multiplied by the coefficient of road surface roughness of bridge deck,in order to consider the effect of surface roughness of bridge deck.This paper aims to apply the automobile impact force on the hollow slab bridge span and through the transient calculation to analyze the stress state of the upper and lower of the hinge joints which is located in most unfavorable position,and explain the mechanism of the disease.