大连星海湾跨海大桥主桥总体设计

Overall Design of Main Bridge of Xinghai Bay Sea-Crossing Bridge in Dalian

大连星海湾跨海大桥主桥为（180＋460＋180）m双层地锚式悬索桥,主梁为钢桁架结构形式,采用整体节点构造,上、下2层桥面板均采用正交异性钢桥面板,桥面上铺装5.5cm厚双层环氧沥青。锚碇采用空腹三角形框架混凝土重力式锚碇,设置在水深20~30m的海床上,锚碇基础采用整体大沉箱,单个沉箱重达26 000t,在船坞内预制完成后用拖轮拖运到桥位处安装在碎石基床上,碎石基床采用升浆技术进行加固。桥塔采用钢筋混凝土框架结构,设上、下2道横梁。主缆由钢丝强度等级为1 770MPa的平行钢丝索股组成,并用长达16m的刚性拉杆锚固在锚碇上,同时采用除湿系统结合传统防腐涂装体系的结构进行防腐,以提高缆索系统的耐久性。

The main bridge of Xinghai Bay Bridge in Dalian is a double-deck earth-anchored suspension bridge with span arrangement of（180＋460＋180）m.The stiffening girder adopts the type of steel truss girder structure with integrated nodes.The upper and lower bridge decks are fitted with orthotropic steel plate deck paved with 5.5cm thick double-layer epoxy asphalt.The anchorages are the concrete gravity anchor blocks with open-web triangular framework,sitting on the seabed that is 20~30munder the sea,the foundations of which adopt the large integrated caissons,each weighing up to 26 000 t.The caissons were prefabricated in the ship yard,and then towed to the bridge site by the tug boats,and sunk to the crushed stone seabed that are strengthened by prepackaged aggregate concrete technology.Bridge towers are the reinforced concrete frame structures,equipped with an upper and a lower cross beams.The main cables are made up of prefabricated parallel wire strands,each with a strength of 1 770 MPa,anchored to the anchor blocks using the 16 mlong rigid anchoring roads.The main cables are corrosion-protected by the dehumidification system combined with the conventional anti-corrosion coating system,so as to improve the durability of the cables and hangers.