Research On Shear Lag Of Cable-stayed Bridge With Steel-concrete Composite Beams

Cable-stayed bridge is a kind of bridge system which is composed of beam,cable and tower.According to the different materials of cable-stayed bridge,it can be divided into concrete cable-stayed bridge,steel cable-stayed bridge and steel-concrete omposite beam cable-stayed bridge.But the use of a single material to build the bridge is difficult to meet the current needs of traffic,steel-concrete composite beam cable-stayed bridge also came into being.In the mixed beam bridge,the steel-concrete composite section is both an important component and a complex part of the mechanical properties.These complexities make the bridge more problematic,one of the problems is the stress distribution of the wide and thin flange plate of the bridge is more uneven and shear lag effect is more obvious and complex.In this paper,the influence factors of shear lag effect are studied,It is found that wide span ratio and the external load have a significant effect on the shear lag effect.The aspect ratio only affects the shear lag effect in a certain range,and the aspect ratio has little effect.Based on the Gaojia Huayuan Bridge as the engineering background,the shear lag effect of the main girder is analyzed.It is found that the diaphragm has a significant effect on the stress distribution of the main girder,which can effectively reduce the shear lag effect.In the steel mixing section,the shear lag effect of the steel box girder is more obvious than that of the concrete box girder,and the stress change of the steel box girder should be paid special attention in the engineering design.In addition,the influence of external load on shear lag effect of main girder is studied.It is found that the external load has little effect on shear lag effect.The finite element software ANSYS and MIDAS / Civil are used to simulate the engineering design and construction monitoring.In the design process of the steel-concrete composite beam cable-stayed bridge,the diaphragm should be arranged rationally,and the effect of the shear lag effect can not be neglected.In particular,the steel-concrete composite section should pay attention to and increase the stress reserve of the combined steel box girder.