ABSTRACT
Large-scale replacement projects for the restoration of old or heavily deteriorated expressway bridges, have recently become a major topic in Japan’s bridge maintenance. In most situations, it is difficult to prepare ground-level construction yards for the demolition of existing viaduct bridges built in already urbanized areas. The degree of difficulty becomes even more severe when the replacement takes place directly above an intersection with heavy traffic. This paper will introduce an aerial-demolition method for an existing PC bridge that allows continuous uninterrupted vehicular traffic and pedestrian access on the ground even while the demolition is taking place. The feature of this demolition method is to complete all the demolition processes that take place above an intersection, such as cutting the bridge into small pieces, lifting them, and conveying them in the air, by using movable workstations, cranes hanging at or placed on the temporary girder laid over the bridge to be demolished.
