Construct a bridge using bailey bridge

In my experience, the Bailey bridge was only used to quickly create a bypass bridge while the old bridge was being demolished and the new bridge was being built.

I would seriously have to question whether a Bailey bridge could support that much concrete. + forms + equipment

Bailey bridges are first class on their own but they have limitations as suitable for supporting pre-cast elements which are to be pre-stressed later. Why ? Because Bailey bridges work mostly in tension, their suitability is inadequate as they sag under load and you would have to compensate that by further strenghtening.

This is feasible by extending upwards and quite considerably. the end frames and having wires from both sides of the frames support the center section of the Bailey spans in order to compensate and or limit the sag of the Bailey elements in the center

I would suggest that you consider the following options:

1.Falsework on piling ( can be : piping, rails, welded box piles i.e Larsen or other welded to form double or triple piles with huge load capacity) . With vibrator hammers/extractors it is very quick to drive and or remove the piles for the next span.

2.You are talking of barges. Obviously there is depth available. My suggestion is that you consider barge supported falsework onto which the pre-fabricated elements have already been placed onto the falsework . Use tide (or jacks ) to line-up the elements in order to thread the tendons .

Where necessary use two barges in order to reduce the draft (and increase stability if the height demands it). Alternatively use an excavator to dig a channel for the barges near the side of the river.

Remember SAFETY is PARAMOUNT . The old method of piling (even wood piling ) which supports your falsework is the safest of them all. There is no cutting corners in Bridge Building. Keep us informed.

Labor Omnia Vincit

I think there is some confusion in terminology. You are probably referring to post-stressing cables which give rise to a prestress in the structure. Recently, I haven't seen many box girder bridges cast in situ; they tend to be cast off site and then installed on site either from a barge crane or launched from the nose or craned into position.

The Bailey bridge idea stems from the re-usability of the items. However, you will always need to adapt the individual parts to suit your particular need. Secondly, as stated in another post, they are quite flexible under loading and therefore probably not suitable as formwork - they will change the formwork's dimensions and therefore risk changing the cover to the concrete which can lead to durability issues and even excess concrete (extra load etc).