某铁路黄河特大桥桥墩改造技术

某铁路黄河特大桥为24×48m单线轨道简支钢桁梁桥,至2018年该桥已运营48年,已不能满足运营要求,需对该桥进行改造。在该桥改造过程中,对桥梁墩台顶部进行加高、加宽处理。为了避免在黄河湿地保护区内搭设落地支架,桥墩改造采用吊架法施工。先利用钢梁快速提升技术将既有钢桁梁提升1.4m,利用墩顶临时钢支撑架支撑固定;凿除原桥墩部分混凝土,安装桥墩加高、加宽结构的钢筋及预埋件;利用分离式走行吊架运输并安装外包钢壳;浇筑桥墩加高、加宽混凝土,完成桥墩改造施工。

Key Techniques for Bridge Pier Reconstruction of a Railway Bridge on Huanghe River

A railway bridge on the Huanghe River, a simply-supported steel truss girder bridge, has 24 spans of 48 m and single track. By 2018, the bridge had been in operation for 48 years and it had been unable to meet the operational requirements. In the process of reconstruction of the bridge, it is required to heighten and widen the top of the bridge abutment needing to be reconstructed. In order to avoid setting up the floor stand in the Huanghe River Wetland Reserve, the hanger method is adopted during the pier reconstruction. Firstly, the existing steel truss beam is lifted by 1.4 m through the rapid lifting technology, and the support is fixed by the temporary steel support on the top of pier. Then, partial existing pier concrete is chiseled away, and steel bars and embedded parts are installed to heighten and widen the pier for reconstruction. Afterwards, separate hangers are used to transport and install steel formwork on the bridge, so that fresh concrete is poured till the pier reconstruction is completed.