Analysis and Calculation of the Force on the Structure of Span-by-span Construction

The system, in the span-by-span construction of bridge, will experience three kinds of shifts from the state of simple beam to the continuous state,from overhanging beam to the continuous beam and from few-spans continuous beam to required degree span by span.Meanwhile, structural calculating graphics and the internal force are changing with the three shifts. Not only the self-weigh of every beam,the prestressing,the compression on the support of form scaffolding,constriction of concrete, creeping are considered when the internal force is calculated, but also the result of displacement and deviation of the support and precamber should be taken into consideration.