BRYAN DARRIN
SENIOR THESIS PRESENTATION
MILLENNIUM HALL
DREXEL CAMPUS
PHILADELPHIA, PA
Millennium Hall
+ Introduction
- General Building Information
- Existing Structural System
- Thesis Objective
- Structural Depth
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
34th Street and Race Street,
Philadelphia, PA 19104
Drexel University
Educational Residence Hall
153,000 Gross S.F.
17 Stories Total
General Building Information
Façade of glass and aluminum
screen curtain wall
Offset of each floor as a
rotation about the central core
creates spiral affect.
[Note: For this entire thesis
project, the spiral affect has
been removed. This
includes all data referred to
as existing design.]
Cast-in-place concrete
+ Introduction
- General Building Information
- Existing Structural System
- Thesis Objective
- Structural Depth
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
110 feet wide
70 feet deep
15 foot cantilever
Flat plate
Concrete moment frame
with concrete shear walls
Existing Building Problems
- Introduction
+ Thesis Objective
- Problem Statement/Solution
- Thesis Goals
- Structural Depth
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
Heavy weight due to concrete
Thick floor slabs due to large cantilever
Thesis Redesign Goals
Depth - Structural
1. Reduce the weight of the overall building by
replacing the gravity system
Redesign Solution
2. Minimize drift with a lateral force resisting
system in coordination with the gravity system
Design as steel moment frame
Use composite deck to reduce thickness
Move column line to exterior
Add braced frames for lateral resistance
3. Verify the impact on the foundation system
Thesis Redesign Goals
- Introduction
+ Thesis Objective
- Problem Statement/Solution
- Thesis Goals
- Structural Depth
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
Thesis Redesign Goals
Breadth #1 - Architectural
Breadth #2 – Construction Management
4. Determine the impact on the architectural
design including floor plan layout
5. Determine the impact that the redesign has
on the construction schedule and cost of the
building
- Introduction
- Thesis Objective
+ Structural Depth
- Gravity Redesign
- Lateral Redesign
- Foundation Check
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
SDL = 20 psf + 15 psf = 35 psf
LL = 100 psf
1.2 SDL + 1.6 LL
- Introduction
- Thesis Objective
+ Structural Depth
- Gravity Redesign
- Lateral Redesign
- Foundation Check
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
L = 35 + 100 = 135 psf > 147 psf
ok
Wu = [1.2(44+5+35) + 1.6(100)](12)/1000 = 3.13 klf
Mu = 452 ft-kips
Use W16x45 with 32 studs spaced at 12 inches
Ram Model
- Introduction
- Thesis Objective
+ Structural Depth
- Gravity Redesign
- Lateral Redesign
- Foundation Check
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
Used to verify hand calculations and determine
column sizes
Full composite construction was assumed
Same loading was used
Results #1
RAM member sizes were found to be close to the
hand calculated but generally smaller.
Results #2
Preliminary column sizes were found
W10x33 Typ.
As large as W10x100 at interior line
Design Loads
- Introduction
- Thesis Objective
+ Structural Depth
- Gravity Redesign
- Lateral Redesign
- Foundation Check
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
Wind controls in the North/South direction:
398 kips
Design Limits (IBC,2006)
(Allowable Building Drift)
Δwind = H/400 = 180*12/400 = 5.4 inches
(Allowable Story Drift)
Seismic controls in the East/West direction:
327 kips
Δseismic = 0.015Hsx = 0.015*10*12 = 1.8 inches
ETABS Design Process
- Introduction
- Thesis Objective
+ Structural Depth
- Gravity Redesign
- Lateral Redesign
- Foundation Check
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
First Evaluation
Model was built in ETABS
Member sizes from Gravity system were used
Columns were aligned with local beam axis
All connections were assigned as moment
connection
Diaphragm was assigned to each floor
Loading patterns for seismic and wind were
placed as individual story forces
Total Drift > 30 inches
Larger member sizes were not making
much improvement
Second Evaluation
- Introduction
- Thesis Objective
+ Structural Depth
- Gravity Redesign
- Lateral Redesign
- Foundation Check
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
Braced frames added to resist
North/South drift
North/South Wind
Maximum drift = 5.33 inches < 5.4 inches
East/West Seismic
- Introduction
- Thesis Objective
+ Structural Depth
- Gravity Redesign
- Lateral Redesign
- Foundation Check
- Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
Foundation Check
20 caissons
Assume equal distribution
920 kips / caisson
32 caissons
Assume interior 10
caissons take half
Maximum story drift = 1.22 inches < 1.8 inches
680 kips / caisson
- Introduction
- Thesis Objective
- Structural Depth
+ Architectural Breadth
- CM Breadth
- Final Summary/Conclusions
Connected directly to column
Connection points every 12 feet
Continuously up building
Existing Cost/Schedule
- Introduction
- Thesis Objective
- Structural Depth
- Architectural Breadth
+ CM Breadth
- Final Summary/Conclusions
Cost/Schedule Comparison
Includes structural concrete, reinforcement, and
framing
Estimated structural cost of $1.7 million
Estimated timeline of 330 days
New Cost/Schedule
Includes steel framing, steel decking, metal studs to
develop composite strength, concrete, reinforcement,
and fire proofing
Estimated structural cost of $2.3 million
Estimated timeline of 130 days
Cost has been increased by $600,000 or by 35%
Schedule has been reduced by 200 days or by40%
Goals Re-evaluated
- Introduction
- Thesis Objective
- Structural Depth
- Architectural Breadth
- CM Breadth
+ Final Summary/Conclusions
Summary
1. Reduce the weight of the overall building by
replacing the gravity system
Steel frame and composite deck provide lightweight
system
2. Minimize drift with a lateral force resisting system in
coordination with the gravity system
Steel braced frames partnered with steel moment
frame reduce drifts to allowable values
3. Verify the impact on the foundation system
Existing caissons have adequate strength for all
columns, most could be reduced in size
4. Determine the impact on the architectural design
including floor plan layout
Minimal façade connection changes and layout
adjustments have little impact on floor plan
5. Determine the impact that the redesign has on the
construction schedule and cost of the building
Structural cost has gone up but entire building
schedule time has been reduced
Summary
- Introduction
- Thesis Objective
- Structural Depth
- Architectural Breadth
- CM Breadth
+ Final Summary/Conclusions
Acknowledgements
I would like to thank:
Met project goals
Structural design is
feasible option
The Harman Group for a unique building idea
Drexel University for allowing me to analyze the
Millennium Hall building
The entire AE faculty, especially my Thesis Advisor
Dr. Hanagan
QUESTIONS?