新建G1501泖港大桥主桥设计

平申线航道(上海段)整治工程中泖港大桥主桥为一座预应力混凝土箱梁与钢箱梁混合而成的桥梁,桥梁的总体跨径布置为65 m+135 m+65 m,其中主跨跨中55 m范围布置了钢箱梁其他部分布置为预应力混凝土连续梁。该桥的主梁在中间桥墩处梁高为7.2 m,高跨比为1/18.75,跨中梁高3.2 m,高跨比1/42.18,混凝土部分箱梁梁底按2次抛物线变化,钢箱梁采用等截面形式。对该桥采用ANSYS软件建立板壳实体模型进行主桥整体分析表明,该桥各个结构部位的受力满足规范要求。该桥的施工方法采用了悬臂对称浇筑混凝土梁段、支架上浇筑边跨混凝土合龙段、施工钢混结合段以及整体吊装钢箱梁节段等。运营情况表明该混合梁结构形式具有优良的力学性能,可供类似工程参考。

Design of Main Bridge for Newly Built G1501 Maogang Bridge

In the Pinghu-Shanghai Channel(Shanghai Section)Regulation Project,the main bridge of Maogang Bridge is a pre-stressed concrete box girder and steel box girder composed bridge.The overall span layout of bridge is 65 m+135 m+65 m,in which the steel box girder is erected in 55-m range in the middle of main span,and the other parts are arranged of pre-stressed concrete box girders.The main girder of this bridge is 7.2 m high at the middle pier,the depth-span ratio is 1/18.75,and the midspan girder height is 3.2 m and the height-span ration is 1/42.18.The beam bottom of concrete box girder is parabolic twice and the bottom of steel box girder is of equal section.The software ANSYS is used to establish the shell solid model for this bridge to analyze the whole main bridge.The analysis shows that the stresses of various structural parts of this bridge satisfy the standard requirements.The construction methods of this bridge are the cantilever symmetrically casting concrete girder section,casting side-span concrete closure section on support,constructing steel-concrete combined section and integrally hoisting steel box girder section.The operation situation shows that the structural form of this composite girder has the excellent mechanical property,which can be referred for the similar projects.