Design of Steel Structures
Homework No.1
Due Date: September 11, 2023
The floor framing plan shown below is typical for a 15-story office building in
Taipei. Please consider live load reduction and answer the following questions
(always consider live load reduction, express the answers in terms of ton force
and meter):
a. Compute the tributary area for Beam B, Girders G1 and G2.
b. Compute the tributary area for Columns C1, C2, C3 and C4 for just one floor.
c. Compute the support reactions, maximum dead and live load bending
moments for Beam B and Girder G1 in a typical floor.
d. Compute the column axial dead load from just one floor for Column C3 by two
approaches:
i. Using the column tributary area.
ii. Adding the beam or girder end reactions together.
e. Compute the total gravity dead load of each floor by
i. Using total floor area.
ii. Adding all column dead loads from just one floor.
f. Find the axial design dead and live loads for Column C2 above the 8th floor
slab.
g. Find the design dead and live loads for Column C4 at the 1st story.
h. The building does not have basement. What is the total weight of the
building?
Using simplified approach, assume the averaged dead load=0.85 tf/m2
(including beams, columns, slab, partition, window wall, ceiling, lighting and
piping), design live load=0.30 tf/m2.
Live Load Reduction:
Y3
“A” is tributary area (m2) of the
member being considered and
B
R ≤ min[60 %, 23.1(1 + D L )% ]
Y2
C3
C4
G1
Y1
X1=9.9m, X2=9.9m, X3=9m
Y1=9m, Y2=12m, Y3=12m
X3
X2
X1
R = 0.85(A - 14m 2 )%,
C2
G2 C1