Punching Shear
Punching Shear
(OP)
I'm going to design a very short span (of 9m 10m long) RC slab bridge carrying one carriageway and a footway with 3 piles at each end (spaced at approx 3.1m spacing).
Since the bridge is very very short, local effects (such as punching shear, transverse bending moment) may be more critical than the longitudinal bending moment.
My boss asks me to use grillage to study the behaviour (the local effects) of the bridge, could anybody give me some clues??
Thanks
Since the bridge is very very short, local effects (such as punching shear, transverse bending moment) may be more critical than the longitudinal bending moment.
My boss asks me to use grillage to study the behaviour (the local effects) of the bridge, could anybody give me some clues??
Thanks





RE: Punching Shear
Usually for highway bridges this long, I have used adjacent precast hollow slab units, with transverse ties at the middle and ends, and place a 150mm mesh reinforced cip concrete slab on top.
RE: Punching Shear
For this span length some states like to use different types of bridges, such as what graybeach has mentioned. I would also consider using a precast concrete arch or three-sided culvert (saves you some design and detailing work also). You are probably past the structure study phase though.
I have done some work in Ohio and for your span range they do like to use slab bridges. Here’s a link to their page, which has a standard design for various spans using AASHTO LFD.
h
I have not really answered you question, but hopefully the ODOT details are helpful.