Study On Resistance To Progressive Collapse Of Half-through Arch Bridge Based On Suspender Breaking

The progressive collapse refer to the failure of the local members of the structure leads to the failure of adjacent components.Finally,it can lead the large scale collapse of the disproportionate with the initial small-scale destruction.In domestic and abroad,the resistance to progressive collapse of the building structure has been a corresponding codes and design process.However,there are few studies on resistance to progressive collapse of bridge structures.On the other hand,it makes the bridge engineering and researchers consider in many ways.Building structures on the resistance to progressive collapse have made a lot of achievements.So it provides a good reference for the resistance to progressive collapse analysis of bridge structures.But the design standards of different structures,the reliability index,the load values and so on are not the same.In summary,this paper analyzes the progressive collapse of half-through arch bridge which is based on the characteristics of bridge structure.It provides a practical reference for evaluating the performance of resistance to progressive collapse of bridges and related design codes.The main work of this paper includes the following three aspects:First of all,this paper summarizes and analyzes the collapse accident of the half-through arch bridge.Meanwhile,the relevant codes of the countries and advances in research on structural resistance to progressive collapse are elaborated.Also summarizes the progressive characteristics of bridge structures,especially arch bridges.Then the three representative arch bridges structure are chosen as the analysis objects.Secondly,the finite element model of three arch bridges with different bridge structures is established.The influence of the breaking of the suspenders on the static characteristics of the structure is analyzed.The floating system of arch bridge occurs lowering of beam on the adjacent deck.This system has low possibility of progressive collapse.When the arch bridge is a consolidation system,it will affect the mechanical performance of the main beam.And there will be a possibility of progressive collapse.Based on the above analysis,the method of the importance coefficient analysis based on the robustness of the building structure is applied to the analysis of the collapse resistance of the half-through arch bridge.The suspender in the mid-span and the 1/4 span position is all important,and there will be greater displacement response under the accidental load.Finally,the half through arch bridge is chosen as the object.Then simulate the time history load of arch bridge suspender breaking response.The stress and displacement of the main beam and the arch rib under the non-damage condition and damage condition are discussed.And the simplified model method is used to calculate the safety factor of resistance to progressive collapse of the bridge deck system.The results show that the Tianyuan bridge has high progressive collapse safety coefficient.Because the load of bridge is loaded by the main beam and the arch rib.