Initial Stress On The Ultimate Bearing Capacity Of Concrete Filled Steel Tubular Arch Bridge

CFST arch bridges have become one of most rapid development bridge structures in recent years,but the design theories are relatively backward Compared with the engineering practice,such as a question of bearing capacity influence of steel tube initial stress to the CFST arch bridge is just one of them. Before the formation of CFST arch bridge,steel tube will withstand itselfweight and wet concrete weight, so this produce the initial stress of steel. In this thesis, Ultimate bearing capacity of CFST arch bridges of initial stress in steel tube steel is simulated by a large general-purpose software ANSYS,and the main result of this paper are presented as follows:1.With the steel tube initial stress considering,the Analysis of Ultimate bearing capacity of CFST arch bridge is achieved by finite element software ANSYS, in which dual non-linear and initial Geometric imperfections is added.2.It mainly analyses how the initial stresses influence the ultimate bearing capacity of single-tube,dumbbell and four limbs latticed CFST arch bridge. Some parameters are studied such as initial slenderness ratio, Steel ratio,material type,rise-span ratio,eccentricity ratio,the way of load etc. If the reduction extent of bearing capacity does not exceed 10%,thus initial stress factor of single-tube,dumbbells and four limbs latticed CFST arch bridge should be separately limited to 0.35,0.6 and 0.6.3. some simplified formula of bearing capacity factor of Initial stress on single-tube,dumbbell and four limbs latticed CFST arch bridge are primarily deduced. The calculated values is colse to finite element results, which have high precision4. construction process of the CFST arch bridge of four limbs latticed with a main span of 368m simulated by the large finite element software ANSYS, the ultimate bearing capacity of which is also analyzed.The results showed that CFST arch bridge with a larger initial stress of steel, and the initial stress caused by the shrinkage and creep can not be ignored;Initial stress not only for long-span CFST arch bridge in-plane ultimate strength to a certain extent, but also for the ultimate bearing capacity of out-of-plane has a impact,which more can not be ignored.