| 摘要 |
PROBLEM TO BE SOLVED: To reduce the amount of used prestressing steel by easily controlling a tensile force of an outer cable by a simple outer cable structure, when a multi-span continuous bridge with the outer cable structure is erected by an incremental launching method. SOLUTION: Cable inserting holes 30a are each pre-formed at upper edges of cross girders 30 which are arranged in positions of a pair of adjacent supporting points, and deflected locking parts 50 are pre-provided in two places at a lower edge of a main girder 20 between the supporting points. In incremental launching erection, the outer cable 40 is inserted into each of the cable inserting hole 30a, and tensioned so as to be linearly pre-arranged at the upper edge of the main girder 20. After the completion of the incremental launching erection, the tensile force of the outer cable 40 is released, and the outer cable 40 is deflected downward so as to be locked to each of the locking parts 50. After that, the outer cable 40 is re-tensioned. Thus, the outer cable 40, which is used in the erection, is diverted to a completed system, so that the amount of the used prestressing steel can be reduced. COPYRIGHT: (C)2005,JPO&NCIPI |
