摘要
重庆白居寺长江大桥主桥为(107+255+660+255+107)m公轨两用双塔钢桁梁斜拉桥,上层设双向8车道城市快速路,宽38 m,下层设双向两线城市轨道,宽19.2 m。交接墩、辅助墩和桥塔横梁处均设置竖向支座,交接墩和桥塔处设置横向抗风支座及横向抗震挡块,桥塔处设置大吨位纵向抗震粘滞阻尼器。主梁为板-桁结合钢桁梁,采用2片主桁倒梯形断面,三角形桁式,主桁横向间距18 m、高12.606 m,节间长15 m。桥塔采用水滴形混凝土结构,总高236 m,设3道横梁。斜拉索采用∅7.0 mm镀锌高强度低松弛平行钢丝HDPE护套成品索,标准抗拉强度1770 MPa,梁端采用创新型双锚拉板锚箱式索梁锚固,塔端采用环向预应力锚固。采用MIDAS Civil软件建立全桥整体空间有限元模型进行静力和动力分析。结果表明:轨道+汽车荷载共同作用下,主桥结构挠跨比为1/1204;最大双悬臂状态和单悬臂状态下结构稳定安全系数分别为17.8和23.4,结构刚度、强度和稳定性均满足规范要求。
The main bridge of Baijusi Changjiang River Bridge in Chongqing is a two-pylon cable-stayed bridge with a span of 660 m,two spans of 255 m and two spans of 107 m.The bridge accommodates two levels of decks,where the upper deck measures 38 m wide,carrying 8 vehicle lanes,and the lower deck measures 19.2 m wide,carrying two urban rail transit tracks.Vertical bearings are installed at the juncture piers,auxiliary piers and the pylon crossbeams,lateral wind-resistant bearings and lateral anti-seismic stoppers are installed at the juncture piers and pylons.Large-tonnage longitudinal viscous dampers are provided at the pylons.The superstructure consists of two 12.606 m-high triangular trusses that are laterally spaced at 18 m and act compositely with the orthotropic steel deck plates,and the typical truss panel length is 15 m.The pylons are water drop-shaped concrete structures rising 236 m,equipped with three crossbeams.The stay cables,each encased in an HDPE duct,are composed of∅7.0 mm galvanized,high-strength,low-shrinkage parallel steel wires,with nominal tensile strength of 1770 MPa.The stay cables are anchored on the deck via an innovative steel anchor box with double anchor tensile plates and to the pylons by loop prestressing tendons.A spatial finite element model of the full bridge was established in MIDAS Civil for static and dynamic analysis.The results demonstrate that the deflection-to-span length of the main bridge is 1/1204 under the combined action of rail transit tracks and vehicle loads.The stability safety coefficients of the bridge structure at the maximum double-cantilever and single-cantilever stages are 17.8 and 23.4,respectively.The structural stiffness,strength and stability of the structure all met the code requirements.
作者
杜春林
周倩
邓宇
涂莹莹
奚绉画
DU Chunlin;ZHOU Qian;DENG Yu;TU Yingying;XI Zhouhua(Chongqing Municipal Design and Research Institute Co.,Ltd.,Chongqing 401120,China;Chongqing Vocational College of Architecture and Engineering,Chongqing 400072,China;T.Y.Lin International Engineering Consulting(China)Co.,Ltd.,Chongqing 401120,China;Sichuan Traffic Technician College,Chengdu 610047,China)
出处
《桥梁建设》
北大核心
2025年第3期126-133,共8页
Bridge Construction
基金
重庆市建设科技计划项目(城科字2023第1-10号)
重庆市自然科学基金面上项目(CSTB2022NSCQ-MSX0661)
重庆市教委科学技术研究项目(KJQN202304301)。
关键词
公轨两用桥
斜拉桥
钢桁梁
倒梯形断面
双锚拉板锚箱
水滴形桥塔
有限元法
桥梁设计
road-light rail bridge
cable-stayed bridge
steel truss
inversed trapezoidal cross-section
anchor box with double tensile anchor plate
water-drop-shaped pylon
finite element method
bridge design
