Pedestrian Bridge b/w two 10 stories tower 3

[zeeshanahmed]

two towers of 10 stories are 30ft apart, and there is a need of pedestrian bridge on every story level between the two towers. Building is in Zone-III. The principle design engineer thinks that it cannot be bridged with a steel structure pedestrian bridge as the buildings are expected to sway upto 4 inches with different mode shapes, Also the second mode shape when both buildings sway towards each other the bridge will come apart.
My question is that is he right ? and is there anyway that we can fit in a steel girder bridge between two towers or not ? how will the joints be detailed to cater building's movement in different mode shapes. ?

 

[rb1957]

271828,
i think the idea is that the tower is free stnading, supporting the bridges and their loads. the bridges would not be tied into the buildings.

i think it's an elegant solution, but i also think the idea hasn't been picked up by the OP, so i guess he's not interested in it.

 

[COEngineeer]

you can make the the 9 free standing and still make it look like they are 9 seperate bridges if you putt some air gap between level.

I am by no mean qualified to do something this massive because all I do is residential. I am just throwing some idea outside the box.

Never, but never question engineer's judgement

 

[271828]

rb, you might be right. There might be some reason that he can't have any columns, however. Perhaps there's a street and/or sidewalk below.

 

[zeeshanahmed]

the idea of the seperate frame was on the table before this post !
This building is actually a hospital, and just below this bridge is the main entrance. The architect is not happy with the idea of any type of hinderance in entrance or its path,
however i am going to discuss it again with the principle engineer and architect.
u know! the idea of a web tappered cantilever from both ends appealed to the architect and he thinks he can do some fancy stuff with it also. Now its just a matter of some analysis.

 

[rb1957]

oh geez, we're not going to let an architect design something ??

not sure where the idea about dividing the bridge in two and anchoring each 1/2 on either building came from ... sounds tricky or awkward to join together in the middle ?

are the floor levels on both buildings the same ?? that would be very fortunate (and unlikely)