Your steel building from homework #1 has progressed in design and your project manager has asked you to work out a few things that the rest of the structural design team can use to help them with their building analysis. Note: use the attached building code excerpts to help you find the answers:
- The architect has requested that there be an area on the roof designed to support a rooftop garden (aka green/vegetative roof) where they plan to host large parties and events such as weddings. What is the uniform live load for this area in psf (unfactored)? (3 pts)
- There is an underground parking garage located below the building, and another engineer on your team needs you to tell them the dead load to put into their analysis model. The floor system consists of a 6″ reinforced concrete slab. There is mechanical ductwork being supported by the floor that weighs 2psf. Assume the concrete beams, girders, and other structural elements weigh 10psf. What is the dead load of the floor system (unfactored)? (3 pts)
- Only passenger vehicles will be permitted to use the parking garage (same one as previous problem, with same dead load). What is the worst-case factored total floor load assuming LRFD load combinations are being used? (3 pts)
- In a wild turn of events the building owner has proposed the building be relocated to Boston instead, where the snow load is 40 psf (this never happens, but just for the sake of the homework). The typical roof is an ordinary flat roof where no assembly is allowed. How much additional load will the typical roof need to be designed for considering the potential change of location? Provide LRFD factored load in psf. (3 pts)
- At the 3rd level there is an open courtyard with a pool. The pool is 4 feet deep. For analysis purposes the water is assumed to be dead load. There is a 12″ reinforced concrete slab that supports the pool. Weight of the plumbing and mechanical systems that service the pool is 20 psf. The other structural elements in the area weigh 10 psf. What is the dead load of the pool area in psf (unfactored)? (2 pts)
- The occupancy on floor 2 of our building is “office”. See below for a typical bay of framing. It does not support a lobby or corridor. Assume the beams are evenly spaced. What is the factored live load maximum deflection of beam “A” assuming beam “A” is a W16x31 with an “E” of 29000 ksi and an “I” of 375in^4? (Hint: Be careful with units! Think practically. If you’re answer isn’t within 0.5″-3″ you’ve done something wrong) (3 pts)