Bridge Slab Overhang Design 2

[KMA]

I have been given the task to analysis a R/C slab for a bridge deck overhang. The overhang will be fixed on one end
(prestressed girder beam flange interface) and free on the other. The free end is supporting a safety shape rail (considered continuous rail). The top steel from the bridge slab runs transverse, and is the main tension reinf. for the overhang. The major load is an HS25 type truck. I am using AASHTO spec. I believe that I can use membrane action and would like to distribute the wheel load longitudinally, more(?) than that allowed by AASHTO (E=0.8*X +3.75). I have heard of design charts (Broussard?), but am not familiar with these. Is the westergaard reference in AASHTO conservative for an overhang? The overhang will not exceed 5ft, and I would like to stay away from grillage or FE analysis. There is only standard dead load from slab wt. & overlay. Will be using Allowable stress design. Any thoughts?

 

[wiktor]

KMA;
I’m seeing no point in complicated analyses for the RC deck, which is rather typical item.
For the overhang design I would advise to follow AASTHO to the point. Imagine some other engineer in the future performing standard load rating – and the result will be substandard deck overhang. And potential savings from these complicated analyses are likely to be close to nil.
The deck reinforcement should be designed as simple as possible, with the typical bay reinforcement extending into overhang and extra rebars added in between as needed.

 

[Qshake]

Please see my post in the structural engineering forum.