The AASHTO pedestrian bridge live load is 90psf nominal and gets a 1.75 load factor for 158psf factored LL. To get that density of people no one will have space to jump or really move at all.
jrs87,
Not sure about the moment of inertia being inadequate, the span to depth looks quite reasonable considering the relatively light nature of the live load but I’ve not made any numbers. My intent was to provide some additional background on concrete trusses, not to defend the concept. It...
Following up on the idea that concrete truss bridges are unprecedented, in fact most of the true cable stayed bridges that Figg has designed utilize essentially a concrete truss spanning transversely across the bridge deck. They pioneered the single cable plane design and use concrete “delta...
Agree with BA, small amounts of axial compression actually increases the section's moment capacity as can be seen in a typical P-M diagram. Running a hand calc on the moment capacity of a concrete section and comparing to an SPColumn run for that same section will provide identical vales at 0...
Dynamic increase factors should be included. I am not very familiar with the provisions of the AREMA code but, I do know that the AASHTO LRFD Bridge code requires a 15% dynamic increase for fatigue checks. This factor is less than that used for the strength level checks (33% for strength).
In the absence of any guidance on this I would use the tension lap limits on non contact splices. WashDOT did some research on non-contact splices for bridge column to drilled shaft connections. It's all for tension laps but, its well done and worth a read. Parts of it have been incorporated...
I would agree with JAE, this type of connection can create eccentricities on the wall studs. I could see this especially being a problem over long spanning headers. Why do you need to balloon frame? If you must, be sure that the lateral load path is complete by including blocking between the...
