Department of Civil Engineering, N-W.F.P UET Peshawar
Hall Design (Option 2)
Note: dg = effective depth of girder = 33″ bwg = width of girder web = 18″ hwg = depth of girder web = 30″ (ii)
(U.D.L)self wt = Factored self weight of girder rib =1.2hwgbwgγc =1.2 × (30 × 18 × 0.15)/144 =0.675 k/ft Part of slab on girder {(U.D.L) sg}:
(iii)
(U.D.L) sg = wu (on slab) x bwg = 0.214 × 18/12 =0.321 k/ft Therefore wg = (U.D.L) self wt + (U.D.L) sg = 0.675 + 0.321 = 1.0 k/ft 81 k
81 k
81 k
81 k
81 k
81 k
81 k
81 k
1.0 k/ft
30.75'
30'
30.75'
Figure 13: Factored loads on girder. Girder spans are according to ACI 8.7. Step No 3: Analysis. (i)
Kinematics indeterminacy of girder: K.I = 4
i.e. (θA, θB, θC, θD) Table 1.7: Slope Deflection Method
span
I (ft4)
l (ft)
I/l
k
AB, BA
1
30.75
1/30.75
1
BC, CB
1
30
1/30
1.025
CD, DC
1
30.75
1/30.75
1
(ii)
Fixed End moments. MF(AB) = wgl2/12 + Pab2/l2 + Pba2/l2 MF(AB) = 1.0 × 30.752/12 +81 × 10.25 × 20.52/30.752 + 81 × 20.5 × 10.252/30.752 = – 632.297 ft-k
Prof Dr. Qaisar Ali (http://www.eec.edu.pk)
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