Craction Analysis Of The Curved Composite Steel-concrete Girder Bridge By The Finite Element Method

In recent years, the steel-concrete composite girder bridge is more and more applied in the continuous beam structure, the continuous bridge received the very big negative moment function in the bridge pier. This time the concretes floorboard was in the pulled area in the disadvantageous stress position. Therefore, conducted the synthetic study to the curved steel-concrete composite girder bridge negative moment area's crack resistance, it is carries on the bridge design reasonably need. At present, domestic and foreign basically is to the straight line built-up beam negtive moment area research. It has made the very big progress, but actually relatively falls behind regarding the curve steel-concretes' research. Therefore, this article in theoretical analysis's foundation, take some curve circular route bridge as an example, provides the parameter according to the design, has compared through the Ansys modelling analysis in different pre-stressed that the different concretes intensity rank, under the different ratio of reinforcement regulatory measures the negative moment area crack resistance energy.The analysis result indicated that:(1) Under self-weight function, the amount of deflection basic the same in and outside of box, the bending moment-amount of deflection relations assume the linear relationship basically. Along with load gradual enlargement, the amount of deflection which in the box produces is smaller than the outside,namely in box's curve throughout above outside.(2) After exerting the pre-stressed that obviously improved the structure crack resistance energy, enhanced the negative moment area concrete slab dehiscence load effectively, and the dehiscence bending moment enhances along with the pre-stressed enhancement. Regarding enhances the concretes intensity rank and the ratio of reinforcement, the scope which the dehiscence load enhances is not obvious, both regarding postpone the structure the dehiscence load effect not to be obvious.(3) Through the contrast crack distribution map, after raising the ratio of reinforcement, crack dehiscence early, once cracking,the concrete slab crack development speed is slow, the crack are many and thin, the distribution is even. It explained that enlarges the ratio of reinforcement suitably can expands certain function to the concrete shrinkage and the crack.