重庆太洪长江大桥主桥设计关键技术

Design Highlights for the Main Bridge of Chongqing Taihong Yangtze River Bridge

重庆太洪长江大桥主桥为跨径808m的单跨简支悬索桥。主桥采用静力限位和动力阻尼组合约束体系,加劲梁采用钢箱梁,加劲梁全宽39.6m,高3.0m;为减轻疲劳效应,主梁焊接接头采用名义熔透深度为80%的加劲肋板厚,采用整体阶段吊装工艺,桥面铺装采用浇筑式沥青混凝土体系。主缆采用强度级别为1 860 MPa的热镀锌高强钢丝,缠包带加除湿机防护体系,PPWS法施工。桥塔为钢筋混凝土门形塔,承台桩基础。南川岸锚碇受总体设计及地形条件限制,采用隧道锚,为国内首座位于极软岩层中的隧道锚;两江新区岸锚碇采用重力式锚碇,前端小后端大的平面造型,原槽现浇工艺,增加了锚碇的侧向摩阻力。

The main bridge of Taihong Yangtze River Bridge at Chongqing is a simply-supported suspension structure with 808 min main span length.The restraint system of static limit and dynamic damping is adopted for the main bridge,and the stiffening girder adopts steel box beams,39.6 min full width,and 3.0 min height.In order to reduce the fatigue effect,the nominal penetration depth of welded joints of main beam is 80% of the thickness of stiffener plate.In addition,the overall segment erection technique is applied for the main girder,and the cast-in-place asphalt concrete are used for the bridge deck pavement.The main cables are made up of the 1 860 MPa hot-dip galvanized high-strength steel wire,with the wrapping belt and dehumidifier protection system,constructed as per PPWS method.The bridge towers adopt reinforced concrete portal structure,the pile cap is with pile foundation.Limited by the overall design and topographical conditions,tunnel-type anchorage is used on the Nanchuan bank,which is the first tunnel-type anchorage in the extremely soft rock area in China.Gravity-type anchorage is used on the river bank of Liangjiang New District side,which is designed to be the plane shape of small at front end and large at back end,while the original slot cast-in-place technology is used to increase the lateral friction of the anchorage.