澜沧江托巴大桥为主跨100m的上承式钢筋混凝土预制箱拱桥,全桥共30个拱箱,采用斜拉扣挂缆索吊装法施工,最大吊重74t。由于施工现场的限制以及传统缆索吊机的不足,为实现缆索吊机可负载条件下往复式实时横移,提出采用双向移动缆索吊机进行吊装。双向移动缆索吊机主要由主索(跨度281m,设计垂度17.5m)、横移系统(由台车和油缸步进液压千斤顶组成)、地锚系统(由地锚梁及预应力锚索构成)、起重及牵引系统、机电设备等构成。按照实际工况设计双向移动缆索吊机的各组件,在双向移动缆索吊机安装后进行测试试验,通过试验后,将该吊机应用于该桥的吊装施工。实践证明,双向移动缆索吊机可以承担吊装任务,实现全桥吊装范围无死角覆盖,可节约工期。
The Tuoba Bridge over Lancang River is a precast reinforced concrete deck box arch bridge with a main span of 100 m. The bridge totally has 30 arch boxes that were constructed, using the fastening stay and the cable crane hoisting and installation methods and the maximum hoisting weight of the boxes is 74 t. Restricted by the working areas at the construction site and the traditional cable cranes were not sufficiently available, to realize the real time reciprocating translation of the cable crane under the load bearing conditions, a bidirectional moving cable crane was proposed for fulfilling the hoisting and installation of the arch boxes. The proposed cable carne was mainly comprised of the main cables (the designed cable span length being 281 m and cable sagging being 17.5 m), translation systems (the trolleys and the cylinder hydraulic jacks), ground anchor systems (the ground anchor beams and the prestressing anchor cables), hoisting and hauling systems and the electromechanical facilities. The various components of the cable crane were designed according to the actual load cases, the cable crane was tested after it was installed in place at the site and was then put in use in the construction of the hoisting and installation. Practice proves the cable crane can fulfill the construction of the hoisting and installation, can reach all areas of the hoisting and installation of the whole bridge with no dead space and can shorten the construction time schedule. ? 2017, Journal Press, China Railway Bridge Science. All right reserved.