LIFTING GANTRY FOR GIRDER ERECTION WORKS OF SUSPENSION BRIDGES

摘要

The present invention relates to a lifting gantry which moves along the upper surfaces of the main cables of a suspension bridge and which lifts a stiffened girder such as a girder forming the upper structure of the suspension structure at a required position. When the stiffened girder of the suspension bridge is temporarily constructed, the lifting gantry according to the present invention can directly transmit a lifting load, which is a load due to lifting the stiffened girder, to the main cables, so that the structure and the equipment of the gantry is simplified and the weight of the gantry is reduced; and can be easily applied to be used even if a horizontal width between the longitudinally moving main cables varies. The gantry according to the present invention comprises: pulley assemblies (1); hanger members (3) including an upper horizontal beam (31), a lower horizontal beam (33), and a vertical beam (32); and moving apparatuses (4). When the stiffened girder (200) is not lifted, the pulley assembly (1) having a cable fastening member (12) coupled to the main cable (100) is hung on the lower horizontal beam (33), so that the load from the pulley assembly (1) is applied to the lower horizontal beam (33), but when the stiffened girder (200) is lifted, the cable fastening member (12) is coupled to the main cable (100), so that the pulley assembly (1) is not directly hung on the lower horizontal beam (33), and, as a result, the lifting load from the pulley assembly (1) is not transmitted to the lower horizontal beam (33).