INCREMENTAL LAUNCHING METHOD FOR THE PRESTRESSED COMPOSITE TRUSS GIRDER AND ITS TEMPORARY SUPPORT SYSTEM

摘要

PURPOSE: An incremental launching method for constructing a composite truss girder bridge and a temporary support system thereof are provided to have no need to increase a thickness of a lower chord of concrete because a composite truss girder bridge can be pressed in a panel point unit by using a temporary support structure and to construct the composite truss girder bridge having a long span more than 70m by using a incremental launching method because a light weight, which is a major advantage of a composite truss girder bridge, can be maintained. CONSTITUTION: An incremental launching method for constructing a composite truss girder bridge is composed like next. Temporary support structures are respectively attached on the front and rear surface of a bridge. A sliding pad(11) is inserted between a concrete lower chord(9) and the temporary support structure when lower panel point of composite truss girder bridge reaches to the front surface of the bridge so that a point is formed. The other sliding pad is inserted into the lower panel point of concrete lower chord reaches to the temporary support structure in the front surface before the inserted sliding pad completely gets out the temporary support structure in the rear surface by passing through a permanent bearing(7) installed in a central part of a pier(6). The lower panel point of composite truss girder is supported in the pier throughout the whole incremental launching process.