上承式预应力混凝土刚性梁柔性拱桥静力分析

上承式刚性梁柔性拱桥通透性好、刚度大。为了明确其受力特性,以某大桥初步设计方案为例,采用有限元法分析比较其在活载作用下结构内力随梁、拱的刚度以及矢跨比等结构参数变化的趋势。结果表明:矢跨比对结构内力影响较大;梁、拱在跨中形成整体断面,刚性梁可平衡拱的推力,同时由于拱的推力部分传递到刚性梁内,可减少纵向预应力筋的用量;与同跨径的连续刚构桥相比,活载挠度小,具有较大的竖向刚度。

Analysis of Static Force of Prestressed Concrete Rigid Girder and Flexible Arch Deck Bridge

The transparency of the rigid girder and flexible arch deck bridge is fine and the rigidity thereof is great.To make clear the force conditions of the bridge,the proposed preliminary design of a bridge of such type was cited as example,the finite element method was used to analyze and compare the changing tendency of the structural internal force of the bridge with the changing of the structural parameters of the girder and arch rigidity and the rise-to-span ratio under the action of live load.The results of the analysis show that the influence of the rise-to-span ratio on the structural internal force is great.The integral section of the girder and arch is formed at the midspan,the rigid girder can balance the thrust of the arch and at the same time,the usage amount of longitudinal prestressing tendons can be reduced because part of the thrust of the arch is transferred to the rigid girder.In comparison to a continuous rigid-frame bridge with the same span length,the rigid girder and flexible arch deck bridge has little live load deflection and considerable vertical rigidity.