Static And Dynamic Analysis Of A Steel Tube Concrete Cross-Section Truss Arch Bridge

As a classical and beautiful bridge form,arch bridge has a long history of construction in China,and it has been the main construction bridge type in the period of agricultural civilization in China.With the application of concrete-filled steel tubular structures in arch bridges,this classic bridge type is more lightweight and more expressive.Since the construction of China’s first concrete-filled steel tubular arch bridge in the 1990s,the bridge type has rapidly gained a large number of applications and rapid development in China’s transportation infrastructure.The upper-supported CFST arch bridge has unique advantages such as simple structure,easy horizontal arrangement and bridge deck support on the column,and has good integrity and lateral stability.It has become a mountain valley with good geological conditions in China.The region has a strong competitive bridge type.In this paper,based on the large and small bridges in Guizhou Province,the full-bridge finite element model with different design parameters was established using Midas/Civil finite element software.The static analysis,self-vibration characteristics and static force of the bridge were established.Based on the stability analysis,the influence of different design parameters on the structural performance is discussed.The main research contents are as follows:The first chapter introduces the development of CFST arch bridges at home and abroad and the research situation of the bridge type in China.The classification of the concrete-filled CFST arches and the characteristics of each type of structure are expounded.The second chapter introduces the engineering background selected in this paper,and gives a brief description of the process of modeling with Midas Civil finite element analysis software.Furthermore,the static response of the bridge under the conditions of dead load,live load alone and different load combinations is analyzed.Finally,the effects of the variation of the sagittal ratio,the number of columns on the arch,and the inclination of the ribs on the static performance of the structure under constant load are discussed.The third chapter introduces the basic concepts related to the analysis of natural vibration characteristics of bridges.It elaborates the finite element numerical analysis method commonly used in the analysis of structural dynamic characteristics,and then uses Midas Civil finite element calculation software to bridge the state of CFST arch bridges.The self-vibration characteristics analysis is carried out to investigate the effects of three design parameters such as sagittal ratio,arch rib stiffness and cross bracing arrangement on the natural vibration characteristics of the structure.The fourth chapter first introduces the relevant theoretical knowledge of the stability analysis of arch bridges.Then the stability analysis of the spatial finite element model of the CFST arch bridge is carried out.The four unfavorable working conditions of the arch bridge are considered.Finally,the effects of saddle span ratio,wide span ratio,temperature change,bearing sinking and arch rib stiffness on structural stability are discussed.