BRYAN DARRIN SENIOR THESIS PRESENTATION MILLENNIUM HALL DREXEL CAMPUS PHILADELPHIA, PA
description
Transcript of BRYAN DARRIN SENIOR THESIS PRESENTATION MILLENNIUM HALL DREXEL CAMPUS PHILADELPHIA, PA
BRYAN DARRIN
SENIOR THESIS PRESENTATION
MILLENNIUM HALL
DREXEL CAMPUSPHILADELPHIA, PA
+ Introduction- General Building Information- Existing Structural System
- Thesis Objective- Structural Depth- Architectural Breadth- CM Breadth- Final Summary/Conclusions
Millennium Hall
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.]
+ Introduction- General Building Information- Existing Structural System
- Thesis Objective- Structural Depth- Architectural Breadth- CM Breadth- Final Summary/Conclusions
Cast-in-place concrete
Flat plate
Concrete moment frame with concrete shear walls
110 feet wide
70feet deep
15 foot cantilever
- Introduction+ Thesis Objective
- Problem Statement/Solution- Thesis Goals
- Structural Depth- Architectural Breadth- CM Breadth- Final Summary/Conclusions
Thesis Redesign Goals
Depth - Structural
1. Reduce the weight of the overall building by replacing the gravity system
2. Minimize drift with a lateral force resisting system in coordination with the gravity system
3. Verify the impact on the foundation system
Existing Building Problems
Heavy weight due to concreteThick floor slabs due to large cantilever
Redesign Solution
Design as steel moment frameUse composite deck to reduce thicknessMove column line to exteriorAdd braced frames for lateral resistance
- Introduction+ Thesis Objective
- Problem Statement/Solution- Thesis Goals
- Structural Depth- Architectural Breadth- CM Breadth- Final Summary/Conclusions
Thesis Redesign Goals
Breadth #1 - Architectural
4. Determine the impact on the architectural design including floor plan layout
Thesis Redesign Goals
Breadth #2 – Construction Management
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 psfLL = 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
- Introduction- Thesis Objective+ Structural Depth
- Gravity Redesign- Lateral Redesign- Foundation Check
- Architectural Breadth- CM Breadth- Final Summary/Conclusions
Ram Model
Used to verify hand calculations and determine column sizes
Full composite construction was assumed
Same loading was used
Results #1RAM member sizes were found to be close to the hand calculated but generally smaller.
Results #2Preliminary column sizes were foundW10x33 Typ.As large as W10x100 at interior line
- Introduction- Thesis Objective+ Structural Depth
- Gravity Redesign- Lateral Redesign- Foundation Check
- Architectural Breadth- CM Breadth- Final Summary/Conclusions
(Allowable Story Drift)
Δseismic = 0.015Hsx = 0.015*10*12 = 1.8 inches
Design Limits (IBC,2006)
(Allowable Building Drift)
Δwind = H/400 = 180*12/400 = 5.4 inches
Design Loads
Wind controls in the North/South direction:
398 kips
Seismic controls in the East/West direction:
327 kips
- Introduction- Thesis Objective+ Structural Depth
- Gravity Redesign- Lateral Redesign- Foundation Check
- Architectural Breadth- CM Breadth- Final Summary/Conclusions Total Drift > 30 inches
Larger member sizes were not making much improvement
First EvaluationETABS Design Process
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
- Introduction- Thesis Objective+ Structural Depth
- Gravity Redesign- Lateral Redesign- Foundation Check
- Architectural Breadth- CM Breadth- Final Summary/Conclusions Maximum drift = 5.33 inches < 5.4 inches
Second Evaluation North/South Wind
Braced frames added to resist North/South drift
- Introduction- Thesis Objective+ Structural Depth
- Gravity Redesign- Lateral Redesign- Foundation Check
- Architectural Breadth- CM Breadth- Final Summary/Conclusions
Maximum story drift = 1.22 inches < 1.8 inches
East/West Seismic Foundation Check
20 caissons
Assume equal distribution
920 kips / caisson
32 caissons
Assume interior 10 caissons take half
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
- Introduction- Thesis Objective- Structural Depth- Architectural Breadth+ CM Breadth- Final Summary/Conclusions
Cost/Schedule Comparison
Cost has been increased by $600,000 or by 35%
Schedule has been reduced by 200 days or by40%
Existing Cost/Schedule
Includes structural concrete, reinforcement, and framing
Estimated structural cost of $1.7 millionEstimated 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 millionEstimated timeline of 130 days
- Introduction- Thesis Objective- Structural Depth- Architectural Breadth- CM Breadth+ Final Summary/Conclusions
Goals Re-evaluated
Summary
1. Reduce the weight of the overall building by replacing the gravity system
2. Minimize drift with a lateral force resisting system in coordination with the gravity system
3. Verify the impact on the foundation system
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
Steel frame and composite deck provide lightweight system
Steel braced frames partnered with steel moment frame reduce drifts to allowable values
Existing caissons have adequate strength for all columns, most could be reduced in size
Minimal façade connection changes and layout adjustments have little impact on floor plan
Structural cost has gone up but entire building schedule time has been reduced
- Introduction- Thesis Objective- Structural Depth- Architectural Breadth- CM Breadth+ Final Summary/Conclusions
Acknowledgements Summary
I would like to thank:
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
Met project goals
Structural design is feasible option
QUESTIONS?