包银高铁黄河特大桥(102+3×178+102)m矮塔斜拉桥设计及创新

Design and Innovation of(102+3×178+102)m Extradosed Cable-stayed Extra Large Bridge of Yellow River Bridge on Baotou-Yinchuan High-speed Railway

包银高铁黄河特大桥在内蒙古磴口县境内跨越黄河主河道,主桥结构形式为(102+3×178+102)m矮塔斜拉桥,塔墩分离、塔梁固结体系。主梁采用单箱双室变截面预应力混凝土箱梁;桥塔采用双柱式矩形截面;每个索塔设8对斜拉索,斜拉索索体采用环氧涂层高强钢绞线,横向双索面布置;桥墩采用钢筋混凝土实心矩形截面,桩基础。通过有限元软件对结构的静力特性、抗震性能、车-桥耦合进行了分析。主要结论及创新点如下:(1)桥梁的强度刚度指标满足规范要求,抗震方案合理,乘车舒适性满足要求;(2)主梁和桥墩之间设置减隔震支座和粘滞阻尼器协同抗震,桥墩在多遇、罕遇地震下均满足安全需要;(3)大位移伸缩装置与轨道伸缩调节器合并设置,解决了温度跨度大和纵向大位移问题;(4)主墩研发了承载力1.3×10^(5) kN的大吨位减隔震支座,相关成果可为类似工程提供参考借鉴。

The main bridge of Baotou-Yinchuan Railway Bridge is designed as(102+3×178+102)m extradosed cable-stayed extra large bridge across the Yellow River in Dengkou,Inner Mongolia with tower pier separation and tower beam consolidation system.The prestressed concrete box beam adopts single box double cell variable cross section.The bridge tower is designed as double column reinforced concrete pylon.Epoxy coated high strength steel strand is used to connect the main girder and the pylon,and each pylon has 8 pairs of stay cables.Horizontal double cable plane layout is employed.The pier is designed as reinforced concrete solid rectangular section with pile foundation.The static characteristics,seismic response and vehicle-bridge coupled vibration of the main bridge are analyzed with FEA software.The main conclusions and innovations are as follows:(1)The strength and stiffness indexes of the bridge meet the requirements of the code,the anti-seismic plan is reasonable and the ride comfort satisfies the requirements;(2)Seismic isolation support and viscous damper are installed between the main beam and the pier for coordinated earthquake resistance,and the pier meets the safety needs under frequent and rare earthquakes;(3)The large displacement telescopic device is combined with the rail telescopic regulator to solve the problem of large temperature span and large longitudinal displacement;(4)The main pier adopts 1.3×10^(5) kN large-tonnage seismic isolation bearing,and relevant achievements can provide references for similar projects.