宝鸡清溪渭河大桥主桥设计

宝鸡清溪渭河大桥主桥为(115+258+115)m的双塔斜拉桥,采用半飘浮的约束体系,桥面全宽29m,设有双向4车道及两侧人行道。桥塔采用钻石形钢筋混凝土结构,主梁采用双边"工"形钢-混组合梁,混凝土桥面板采用预制构件,在纵梁、横梁及人行道托架顶部均设有混凝土后浇带,通过剪力钉与钢主梁连接。斜拉索采用扇形布置的空间双索面平行钢丝拉索体系,通过钢锚箱和锚拉板分别与桥塔和主梁相连。桥塔和边墩基础采用钻孔灌注桩基础。桥址位于高烈度地震区,采取了在桥塔处设置纵向活动抗震球型支座、边墩设置纵向活动横向摩擦摆减隔震支座,在桥塔下横梁与主梁间设置纵向粘滞阻尼器的减隔震措施。根据结构特点以及建设条件,主梁施工方案采用大节段支架法。

Overall Design of Main Bridge of Qingxi Weihe River Bridge in Baoji

The main bridge of Qingxi Weihe River Bridge in Baoji is a two-pylon cable-stayed bridge with three spans of 115,258 and 115 m.The bridge is of a half-floating restriction system,with a total deck width of 29 m,accommodating 4 traffic lanes(two on each direction)and 2 sidewalks.The pylons are diamond-shaped reinforced concrete structures.The main girder adopts the composite girder of double I steel beams and precast concrete slabs.On the tops of the stringers,cross beams and sidewalk brackets,wet concrete stitches are poured in situ.The concrete slabs are connected with the steel main beams via shear studs.The stay cables are formed of parallel steel wires,fanned out in spatial double cable planes,and connected to the pylons and main girder via steel anchor boxes and tensile anchor plates,respectively.The pylons and the side piers all stand on bored pile foundations.Due to that the bridge is located at the intense earthquake zone,the spherical bearings accommodating longitudinal movement are installed at the pylons,transverse frictional pendulum bearings capable of seismic mitigation and isolation and accommodating longitudinal movement are installed on the side piers,and longitudinal viscous dampers are installed between the lower cross beam of the pylon and the main girder to absorb seismic vibration.In accordance with the structural characteristics and construction condition,the main girder is divided into large segments and erected with assistance of scaffoldings.