R In this assignment, you will be examining the framing elements for a proposed three story precast concrete office building and the various loads that are expected to act on them. You will use the ACI load combination equations to determine the critical loads for design. Finally, you will apply the principles of statics and strength of materials to determine the factored shears, moments and axial forces for design. The first floor will consist of a floating slab on grade that is isolated from the rest of the structure. The second and third floors as well as the roof will be supported by a series of 20 inch deep double tees that will be covered with a 2 inch thick concrete topping. The interior ends of the double tees will rest on and transfer the loads to interior precast girders. The exterior ends of the double tees will rest in pockets in the spandrel girders. The girder ends will bear on column haunches. The floor-to-floor and floor-to-roof heights will be 14 feet. Anticipated loads for the structure are shown below. Those listed as TBD are to be determined by referring to the handout on dead and live loads given to you during lecture. FLOOR: Structural double tees - total weight each 2 inch topping HVAC, plumbing, electrical, lighting & ceiling Hardwood Flooring inch thick Acoustic ceiling tile & track Moveable partition load 18,800 lbs. TBD 18 psf TBD TBD TBD TBD Live load- open office area ROOF: Structural double tees-total weight each 2 inch topping Roofing, built-up 5 ply with gravel HVAC, plumbing, electrical, lighting & ceiling Acoustic ceiling tile & track Roof live load Snow load Rain/ice load 13,440 lbs. TBD TBD 18 psf TBD 30 psf 45 psf 25 psf Estimated girder size (all interior girders): 20 inches wide x 36 inches deep Spandrel girders are deep rectangles with an estimated weight of 650 lbs. per lineal foot that will serve as the finished exterior walls. They will also carry window loads at the second and third floor levels that add an additional 35 lbs per lineal foot. Estimated column size (all columns): 20 inches x 20 inches Refer to the attached sheets for a transverse section, typical floor and roof framing plans, and pictures of the building. Required: (1) Derive the magnitude of the uniform factored load that a typical second floor double tee will double tee. Draw the factored shear and moment diagrams showing the critical values needed for support based on the loads and dimensions given. Compute the reactions at each end of the design. (2) Do the same for a typical double tee supporting the roof. (3) Derive the magnitude of the factored load that a typical second floor G2 girder will support based on the loads and dimensions given. Compute the reactions at each end of the girder. Draw the factored shear and moment diagrams showing the critical values needed for design. (4) Compute the magnitude of the factored axial load that a typical Cl column will support at its base. (5) Compute the magnitude of the factored axial load that a typical C3 column will support at its base. Remember to take into account the floor openings at both the second and third levels. Coumn haunch Roof Concrete topping Third Floor Double bee- Spandrel girder vtenor grder Second Floor Column Foundation Concrete slap Taroverse building section First Floor 091 E 28-0 D-522 A Pouble tee (PT) Double tee on 200 @ 25-0 400 400 562 Double tee m Double teen 400 561 [82] 40-0 302 #1- DT DT DT 9 DT DT DE 5 DT PT 55 55 55 56 5 120 DT 5555& laz Copen to below> DT CADRA P DT C2 561 Place Framing Plan 40-0 e DG 02 S 40-0 (4 DT DT EX 8. PT. 2 DT PT DT Dr DT S PT e DT DT PT 162 DT DT PPT DT D PT DT DT 361 DT 8 PT PT PT Roof Framing Plan