京张高铁官厅水库特大桥总体设计及创新技术

官厅水库特大桥为冬奥会交通保障项目京张高铁重点工程"一桥两隧"中的"一桥",全桥长9 077.89 m,是全线重点工程。主桥跨越北京市备用水源地、一级水源保护区官厅水库库区,环保要求极为严苛。大桥设计采用多孔曲弦钢桁梁桥式,主桥长度880 m,上部结构为华伦式桁架、钢-混组合桥面,下部结构采用双柱式桥墩,为减少地震位移主桥两端设置阻尼器。桥上铺设CRTSⅠ型无砟轨道,通过整体—局部刚度匹配,控制了桥轨变形,列车设计速度达到350 km/h。主桥采用大跨度顶推法施工,配合超耐候钢桥防腐涂装、长寿命开放式桥面雨水收集系统等创新技术,大幅降低桥梁施工、线路运营、维修养护对官厅水库水体的影响,保护了环境。配套研发了曲弦桁架智能检查车,非检修期可自主装卸回库贮存保养。

General Design and Innovation of Extra-long Bridge over Guanting Reservoir on Jingzhang High-speed Railway

Guanting Reservoir Bridge is one of the main traffic supporting infrastructures for the Olympic Winter Games, and the total span is 9 077.89 m. It is a major project along Jingzhang High-speed Railway. The main bridge spans over the Guanting Reservoir which is the reserved water source and primary water conservation area of Beijing, and the environmental protection requirement is very strict. The main bridge is a multi-span curved steel truss with total length of 880 m. The warren truss with concrete and steel composite deck is supported by double-column piers. Dampers are installed at two ends of the main bridge to reduce the displacement caused by earthquake. CTRS I ballastless rail track is laid on bridge deck. By matching local and overall stiffness, deformation of the bridge track is controlled and the design speed of 350 km/h is reached. Incremental launching method is adopted in the main bridge construction, combined with high performance weather resistant coating and opened rain water collection system, adverse impact by construction process, railway operation and maintenance on the reservoir is reduced. Curved truss intelligent inspection vehicle invented for this project can load and unload itself from and to the storage-service position during non-inspection time.