Deck sucker principle(variable depth of bridge deck)
For bridges with continuous spans. the maximum sagging moment will be at span mid. and the maximum hogging moment will be above the pier
By increasing the depth of the deck above the pier. this will result in increasing the hogging moment above the pier and sucking or reducing the sogging moment. therefore the depth will be reduced at the mid of the span.
Deck sucker principle benefits
- significant reduction of superstructure dead weight. the reduction is larger than a voided slab with the same span length.
- where the headroom requirement is important. this type of construction will provide a more height clearance compared to deck with constant depth
- in terms of aesthetics. this kind of construction contains arches and looks better for the public.