牛田洋大桥主桥结构设计

Structural Design of Main Bridge of Niutianyang Bridge

汕头牛田洋大桥主桥为公轨两用半飘浮体系双塔斜拉桥,跨径布置为(77.5+166.1+468+166.1+77.5)m。公轨分层布置,上层通行8车道公路,下层通行双线跨座式轨道。主桥采用纵、横向正交分离的减隔震约束体系。主梁采用带副桁的板桁结合钢桁梁,空间三角形桁式,桁高11 m、宽16 m,标准节间长15.1 m,采用大节段全焊制造。中跨、次边跨公路桥面采用正交异性钢桥面板,边跨公路桥面采用混凝土桥面板。塔柱采用厝角头造型,全高182.9 m,设3道横梁。塔柱基础采用哑铃形承台+大直径变截面钻孔灌注桩。斜拉索采用7 mm平行钢丝索,强度等级为1770 MPa。理论分析和试验研究表明,大桥具备良好的静、动力性能。

The main bridge of Niutianyang Bridge in Shantou is a two-pylon cable-stayed bridge of a half-floating system,which has a main span of 468 m,two side spans of 166.1 m and two secondary side spans of 77.5 m.The bridge accommodates road and light rail traffic,with 8-lane roadway on the upper deck and double straddle-type light rails on the lower deck.The seismic isolation system of the bridge features the orthogonal separation of force transmission in the longitudinal and transverse directions.The superstructure is a combined orthotropic plate and steel truss structure with secondary trusses.The steel trusses are triangular trusses,measuring 11 m deep and 16 m wide,and a standard truss panel is 15.1 m long.The steel truss is welded into a large integral panel from individual members.The decks in the central and secondary side spans are orthotropic steel deck plates,while the decks in the side spans are concrete deck slabs.The pylon column is 182.9 m in total height,fitted with three cross beams and decorated with“cuojiaotou”,which is a kind of prevalent decorative walls on the roof of traditional houses in Chaoshan region of China.The pylons are mounted on dumb-bell shaped pile caps that are supported by large-diameter bored piles of variable cross-section.The stay cables are composed of parallel steel wires of 7 mm in diameter,with tensile strength of 1770 MPa.The theoretical analysis and experimental tests demonstrate that the static and dynamic performance of the bridge is good.