kareng
Structural
- Nov 21, 2006
- 9
Hi all,
I have an existing 3" steel composite deck with 4" concrete (7" total) then an additional 3.5" concrete topping, 1.5" setting bed and 4" of pavers that is an exterior plaza over a parking garage. The deck is supported by steel beams 9'-0" o.c. with shear studs, and there is no reinforcement in the slab. (There is likely WWF but who knows where in the depth) I need to calculate the allowable concentrated wheel load on the plaza for large trucks, forklifts and other equipment to be driven on top. I've determined that the beams and connections do not control - the slab does. I'm using the SDI procedure published in the 1997 Composite Deck Design Handbook to calculate the capacity of the deck. This procedure uses PL/4 to calculate moment on the slab due to the concentrated load. I have a few questions:
1. Is it viable to distribute the wheel load in the direction of the span at a 45 degree angle through the pavers/setting bed/topping to get a short distributed load instead? This lowers my moment and gives a bit more capacity, but since the procedure includes a topping I'm wondering if it's already incorporated. I'd ask SDI but they are apparently closed for the week!
2. I am planning to use a dynamic load factor of 1.2 for the moving vehicles, but I haven't found a lot of information to back this up. ASCE has 1.2 for machinery, AASHTO 1.3 for bridges. Is there a dynamic load factor for slow-moving vehicles?
3. Does anyone know of any other good references that can be used for this calculation?
Thanks!
KarenG
I have an existing 3" steel composite deck with 4" concrete (7" total) then an additional 3.5" concrete topping, 1.5" setting bed and 4" of pavers that is an exterior plaza over a parking garage. The deck is supported by steel beams 9'-0" o.c. with shear studs, and there is no reinforcement in the slab. (There is likely WWF but who knows where in the depth) I need to calculate the allowable concentrated wheel load on the plaza for large trucks, forklifts and other equipment to be driven on top. I've determined that the beams and connections do not control - the slab does. I'm using the SDI procedure published in the 1997 Composite Deck Design Handbook to calculate the capacity of the deck. This procedure uses PL/4 to calculate moment on the slab due to the concentrated load. I have a few questions:
1. Is it viable to distribute the wheel load in the direction of the span at a 45 degree angle through the pavers/setting bed/topping to get a short distributed load instead? This lowers my moment and gives a bit more capacity, but since the procedure includes a topping I'm wondering if it's already incorporated. I'd ask SDI but they are apparently closed for the week!
2. I am planning to use a dynamic load factor of 1.2 for the moving vehicles, but I haven't found a lot of information to back this up. ASCE has 1.2 for machinery, AASHTO 1.3 for bridges. Is there a dynamic load factor for slow-moving vehicles?
3. Does anyone know of any other good references that can be used for this calculation?
Thanks!
KarenG
