A reinforced concrete bridge structure is shown in the figures provided that consists of a one- way 11-inch reinforced concrete slab (i.e., the slab spans in the N-S direction). The reinforced

concrete slab is supported by a total of two concrete beams that sit on bridge concrete piers. Furthermore, concrete railing walls are provided where indicated. You have been tasked by your project supervisor to design the flexural reinforcement for these concrete beams. However, in order to select the appropriate flexural reinforcement, you need to first calculate the maximum moment demands from the loads. Given the following: Concrete density: ► normal weight concrete = 150 lb/ft³ [pcf] Design service loads: > Superimposed Dead Load (DL)-25 psf (this is a DL in addition to selfweight DL) > Selfweight DL (you must determine this from the information given in the figures....make sure to calculate selfweight from all bridge components) > Live Load (LL) = 300 psf Part (1) Determine the total DL and total LL beam reactions at beam supports located at Grids B2 and C2. The beam supports can be idealized as simply supported (i.e., pin and roller as shown in the figure). Furthermore, the slab that is supported by the beams can also be idealized as simply supported but spanning in the N-S direction as shown in the figure. Hint: You will need two free-body-diagrams. A FBD of the slab acting as a simply supported beam with a cantilever at each end and a FBD of the beam along Grid 2 also as a simply supported beam with a cantilever at each end. You will need to calculate the reactions from one of these FBDs to use as the loading of the other FBD. This part of the homework assignment is an exercise in following the load path. Part (2) Draw the shear (V) and bending moment (M) diagrams for the total combined DL and LL service loads for the beam along Grid 2. Be sure to show all appropriate numerical values on these diagrams./n6-0 12'-0" 4'-0" North 10'-0" 11" concrete slab 6" thick concrete wall guard ralling 36" PLAN 4'-0" 24"x36" conc. beam below 32-0" 24"x36" conc. beams 12-06-0 SECTION ELEVATION slab span bridge pier below (typ.) 13'-0" 4'-0" bridge piers Note: concrete wall guard railing not shown.