Final Presentation
for
CE 331 Introduction to Structural Engineering
Your Assignment for Project 2 was to:
Visit a construction site
Photograph structural components,
copy structural drawings
Calculate structural adequacy
Create an interesting presentation that:
Describes your structure
Pu
Pn
UC 
Pu
 Pn
Summarizes your structural analysis
The following slides are examples.
Feel free to use copy and paste any
sketches into your own presentation.
Gravity Load
Analysis for Sears
Tower
by
Matt Damon and
Jennifer Lopez
for
CE 331, Spring
2007
Project 2
The Sears Tower is a 108-story steel-frame
office building in downtown Chicago Illinois.
(Original) Owner: Sears & Roebuck Co.
Contractor: Morse-Diesel Inc.
Structural Engineer: Skidmore, Owings,
and Merrill
The Sears Tower is constructed of nine
steel “tubes”, each 75 feet across.
Insert several slides using your own photos here.
We analyzed a typical interior
column and spread footing.
- steel roof deck
- bar joist
- joist girder
- steel tube column
- reinforced concrete foundation
Elevation View
Roof dead load = 14 psf
Section of Roof
waterproof membrane
4 psf
steel deck
4 psf
purlins
3 psf
suspended ceiling
2 psf
sprinklers
1 psf
14 psf
We checked the design of an interior
column for axial buckling.
Pu
 Pn
Column live load = 15 psf
Interior Column
Specified live load = 20 psf
Column live load = 15 psf
specified live load = 20 psf
tributary area = 525 sf
live load reduction factor = 0.75
reduced live load = 15 psf
Factored load to column (Pu) = 30.6k
Pu
Pu = [ 1.2 (14psf) + 1.6 (15psf) ] (30ft)(25ft) = 30.6k
Column capacity (Pn) = 44k
failure mode:
axial buckling
grade 50 steel
E = 29,000ksi
fy = 50ksi
HSS 3x4x3/16
slenderness (kLu/r)
r = 23.4in
k = 1.0
Lu = 10.5ft
AISC Table
Pn = 44k
Design check shows column design is OK
Pu
 Pn
Pu
30.6k
UC 

 0.82
k
 Pn (0.85)(44 )
We checked the design of a typical reinforced
concrete spread footing for flexure failure.
Flexure failure occurs when demand (Mu)
exceeds capacity ( Mn).
Pu, factored axial force from column
location of flexure failure
factored soil pressure, qu
C
T
qu
Mn
Mu