ABSTRACT

As has been stated elsewhere in this book, building box girder bridges in long lengths in-situ is a slow and diffi cult task, prone to defects and delays, tying up expensive falsework for relatively long periods. These diffi culties have been the stimulus for the adoption of segmental methods of construction, such as cast-in-situ balanced cantilever and incremental launching. However, both these methods are only applicable to bridges of suitable layout and geometry. Many bridges, particularly in towns, have span layouts and geometry that are not regular, constrained by the urban fabric.