简支转连续箱梁.doc

摘要 预应力混凝土连续箱梁桥结构刚度大，动力性能好，主梁变形挠曲线平缓，有利于高速行车，连续梁在活载作用下，因主梁连续产生支点负弯矩，对跨中正弯矩有卸载作用，其弯矩分布较合理。目前在公路桥梁工程中应用非常广泛。 本设计主梁就选用了预应力混凝土连续箱梁，完成了营双高速公路马跑沟河大桥4×30 m连续箱梁桥的设计。大桥正跨马跑沟河，为“U”字形河谷，工程地质分区属于冲洪积平原地址区，桥址位于管子沟河道及两岸，河道两岸地势较为开阔。在本次设计中，首先进行了桥址资料和设计标准的阐述，然后确定了预应力混凝土连续箱梁桥为本设计采用的方案，就其进行了结构设计，设计的主要内容有：拟定截面尺寸；计算控制截面的设计内力及其相应的组合值；估算预应力钢筋的数量并对其进行布置，边跨采用15.2的预应力钢绞线1每束6根，N2、N3、N4每束5根。在中跨跨中采用38根钢绞线，N1、N2、N3每束5根，N4每束4根；计算主梁截面的几何特征值；承载能力极限状态验算和正常使用极限状态验算；正常使用极限状态下构件抗裂性及变形验算；持久状态下和短暂状态下构件截面应力验算。经检算，设计的桥梁结构安全，合理，并满足现行规范的要求。 关键词：预应力、连续箱梁、方案比选 Abstract Prestressed concrete continuous box girder bridge structure stiffness, good dynamic performance, deformation of main girder deflection curve is gentle, high speed driving, continuous beam bridge under live load, because the girder continuous generation of negative bending moment of the supporting point, the span is bending moment unloading effect, and the bending moment distribution more reasonable. At present, in the road and Bridge Engineering in a wide range of applications. The design of main girder with prestressed concrete continuous box girder, completed the design of 4×30m continuous box beam bridge over the Mapaogou river from the YingShuang freeway.The bridge is to mount the Mapaogou river, U shaped Valley, engineering geological zoning belongs to the alluvial plain of address area, bridge is located at River and cross pipe ditch, river more open terrain. In this design, the first such material and design standard paper, and then determined the prestressed concrete continuous box girder bridge for this design USES the scheme, the structure design, the design of the main content: formulation of section size calculation control section; the force and its combination value; estimation of prestressed reinforcement quantity and its layout, side span with 42root diameter 15.2prestressed steel strand, N1 each bundle of 6 root, N2, N3, N4each bundle of5root. In the span of 38steel strand, N1, N2, N3each beam5, N4 each bundle of 4 r