上海市金山区紫金大桥设计

Design of the Zijin Bridge of Jinshan District,Shanghai

上海市金山区紫金大桥为钢梁-钢拱下承式系杆拱桥,主跨跨径188 m。大桥主拱为提篮式钢箱拱,矢跨比为1/5,内倾角度12°,拱轴线为二次抛物线。主拱肋截面为矩形,宽2.2 m,高2.8 m。两片拱肋之间设置6道钢箱横向风撑,风撑外设椭圆形装饰结构。大桥主梁为采用新型钢-混凝土组合桥面板的钢梁,全宽40 m。吊杆采用高强平行钢丝束,纵向间距9 m。主拱与主梁连接处采用整体式节点板,拱肋水平推力通过整体节点板传递给钢主梁,大桥外部呈简支支撑体系。大桥主墩采用柱式墩,每个墩柱下设置一个矩形承台,横向两个承台之间通过系梁连接。基础采用钻孔灌注桩,每个承台下布置16根直径1.0 m的钻孔灌注桩,横向系梁下布置3根直径1.0 m的钻孔灌注桩。

The Zijin Bridge in Jinshan District of Shanghai is a steel beam-steel arch through tied arch bridge with a main span of 188 M.The main arch of the bridge was a basket-type steel box arch with a rise-span ratio of 1/5,an inclination angle of 12 degrees,and the arch axis was a quadratic parabola.The section of main arch rib was rectangular,2.2 m wide and 2.8 m high.Between the two arch ribs,there were six steel box lateral wind braces,and the wind braces were equipped with oval decorative structure.The main girder of the bridge was a steel girder with a new steel-concrete composite deck,with a full width of 40 m.The suspender was made of highstrength parallel steel wire bundles with a longitudinal distance of 9 m.The main arch was connected with the main girder by the integral joint plate.The horizontal thrust of the arch rib was transferred to the steel main girder through the integral joint plate,and the external part of the bridge was a simple-supported system.The main pier of the bridge was a column pier with a rectangular cap under each pier.The two caps were connected by tied beams in the transverse direction.The foundation adopted bored cast-in-place piles,16 bored cast-in-place piles with a diameter of 1.0 m are arranged under each cap,and 3 bored cast-in-place piles with a diameter of 1.0 m were arranged under the lateral tie beam.