Nijad Rudy Boukhalil structural option spring - PowerPoint PPT Presentation

About This Presentation
Title:

Nijad Rudy Boukhalil structural option spring

Description:

Nijad Rudy Boukhalil structural option spring 05 – PowerPoint PPT presentation

Number of Views:87
Avg rating:3.0/5.0
Slides: 40
Provided by: nrb3
Learn more at: https://www.engr.psu.edu
Category:

less

Transcript and Presenter's Notes

Title: Nijad Rudy Boukhalil structural option spring


1
Nijad Rudy Boukhalilstructural optionspring05
                                              
2
Presentation outline
  • Project background
  • Existing conditions
  • Problem statement
  • Proposed solution
  • Floor system
  • Lateral system
  • vibration
  • Construction management
  • Recommendations
  • Acknowledgements
  • questions

3
Project background
  • Location
  • on the corner of Bellevue Way
  • 5 stories
  • 3 above ground
  • 2 level parking
  • 39,000 square foot
  • Rectangular shape 131x147
  • Many openings
  • Project cost 14 million

4
Project background
  • The museum has
  • four classrooms for its Museum School
  • three interactive Explore Galleries
  • a 90-seat auditorium
  • a multimedia library
  • a Museum store
  • a small sidewalk café
  • 2 story atrium
  • Outdoor terraces

5
Project background
  • Project team
  • general contractor Sellen construction Co.
  • mechanical design/build contractor Mckinstry
    Co.
  • design architect Steven Holl architects
  • Associate ArchitectSclater Partners Architects
  • structural engineer Skiling Ward Magnusson
    barkshire, inc

6
Project background
  • Architectural layout
  • 3 galleries
  • 3 light qualities
  • 3 actions - see/explore/make (art, science,
    technology)
  • 3 main levels
  • 3 circulation directions

7
Existing conditions
  • Floor system
  • Composite steel deck
  • 3.5 concrete
  • normal weight concrete
  • compression strength fc 4000 psi
  • 3 metal deck
  • shear studs
  • Advantages
  • Good with Long span
  • efficient and economic
  • Good strength to weight ratio
  • Smaller foundation needed
  • Disadvantages
  • Crane demanding
  • Difficult coordination
  • vibration

8
Existing conditions
  • Lateral system
  • Shear walls
  • 10 Cast-in-place
  • 5 reinforcing bars
  • bearing walls along perimeter and core
  • around openings and the atrium.
  • Advantages
  • The cast in place system structure that is free
    of joints.
  • achieve a continuous appearance of the applied
    finishes.
  • ? provide the architect with the desired
    architectural finish

Shear walls
9
Existing conditions
  • Seismic Load Calculations (ASCE 7-02)
  • Assumptions
  • Occupancy Category III
  • Seismic Use Group II
  • Site Class D
  • Seismic response coefficient R6

10
Problem statement
  • Seismic hazard effect
  • Half of the states
  • 109 million people
  • 4.3 million businesses
  • More frequent vibration ? key issue for a museum
  • Original system
  • Floor system Composite floor
  • Lightweight system ? more subjected to vibration
  • Lateral system Shear walls
  • Good choice against earthquakes
  • Earthquake Cost damage
  • Direct cost 1 billion/year
  • indirect business losses 2 billion/year

11
Proposed solutions
  • floor system
  • How vibrations dies out
  • Stiff diaphragm ? share the earthquake forces
  • Joist system
  • ? spacing 2ft o.c (for vibration)
  • Advantages of joist
  • Lighter Weight
  • reduce sizes of beams, columns
  • Various sizes Good for long spans
  • Lowers the overall cost of the project
  • Construction Speeded
  • Each joist is a complete and independent unit.
  • Allows field work to progress efficiently.

12
Proposed solutions
  • Lateral system
  • types of Lateral Systems
  • Bracing
  • Moment Frame
  • Why choose brace frames
  • Have same advantages
  • used where shear walls are impractical.
  • Advantages of Braced Frames
  • High Strength and Stiffness
  • Minimizes Deflections
  • Uses less Material
  • Cost Effective Efficient and Economical
  • Strong visual element
  • speedy erection for faster return.
  • More flexible to future changes than shear walls

13
Proposed solution
  • Different types of bracings
  • Single Diagonals
  • has to resist tension and compression caused by
    sideways forces in both directions on a frame.
  • Cross Bracing
  • only need to resist tension
  • one brace is in tension for the sideways force in
    one direction on the frame,
  • the other brace is in tension when the force is
    reversed.
  • This is the most widely used type of bracing
    system.

14
Proposed solution
Moment frame
  • Why moment frames ok
  • Obstructions rejected
  • eliminates space limitations of solid shear walls
    braced frames.
  • Advantages
  • Allows for windows in walls, and other open
    spaces
  • Disadvantages
  • Large deflections
  • Larger Members
  • Cost increase

15
floor system
  • Joist system using Vulcraft
  • Spacing 2 o.c.
  • Supports unchanged slab
  • 3,5 concrete
  • 3 deck
  • Typical bay

16
floor system
  • Stress analysis
  • The areas to be concerned about were around the
    elevator core and the openings

17
floor system
  • Moment diagram analysis

18
floor system
  • Encountered problem
  • A suspended stairway transports the visitor to
    the third floor along the north wall over head

19
floor system
  • Size up the beam
  • The right side beam of the staircase is required
    to be a W 40 X 183. The columns at the left
    support of the beam are a W 14X145, and the
    column at the right support is a W10X45 as shown
    in the figure below.
  • Analysis in Etabs of the W 40 X 183
  • Deflection governed
  • The beam is spanning 60 feet, and with the shear
    walls gone, a W beam less than a W 40 X 183 will
    deflect more that L/480 1.5

20
Lateral system
  • Changes
  • Core around elevator
  • Shear walls ? braced frames
  • Add columns to replace shear walls
  • Need moment frames around openings

21
Lateral system
  • Core
  • Braces W12x96

22
Lateral system
  • New columns in floor plan

23
Lateral system
  • Bracing
  • West facade

24
Lateral system
  • Bracing
  • South facade

25
Lateral system
  • Bracing
  • East facade

26
Lateral system
  • Type of moment connection
  • SidePlate
  • Ideally suited against seismic
  • Up to 25 Reduction in Lateral Frame Tonnage
  • Up to 50-65 Reduction in    Field Welding
    Man-Hours

27
Lateral system
Moment connection distribution
28
Lateral system
  • ETABS was used to design the lateral force
    resisting system of the building
  • IBC 2000 earthquake pressure
  • ASCE 7-98 wind pressure.
  • Check
  • Deflection
  • Drift ? controls

29
Lateral system
  • Lateral drift

Level Height Disp Drift limit (H/400)
roof 60 0.72 1.8 Pass
3rd 34 0.48 1.02 Pass
2nd 18 0.15 0.54 Pass
30
Vibration
  • Floor vibration
  • Human activities walking
  • Room north gallery on 3rd floor
  • Vibration expectation small to nonexistent
  • Use design guide 11 from AISC
  • Goal to understand which system is more adequate
    for vibration
  • ? compare existing/new system

31
Vibration
  • Existing system
  • Composite steel deck

32
Vibration
  • Modified system
  • Joist floor system

Both systems have the approximately the same
percentage of the acceleration of gravity and are
satisfactory to damp vibration while walking in
the North gallery of the BAM.
33
Cost comparison
34
Cost comparison
  • Redesigned floor system

35
Cost comparison
  • Existing lateral system

36
Cost comparison
37
Recommendations
  • Disadvantages of Braced Frames
  • Obstructiveinterfere with architectural
    requirements
  • Low Ductility
  • Disadvantages of Moment Frames
  • ExpensiveLots of material plus labor-intensive
    connections.
  • Low Stiffness

decision
  • Floor system joist
  • Less expensive
  • Vibration checked
  • lateral system shear walls
  • Less expensive
  • Drift checked

38
acknowledgments
  • Thank you

faculty
Steven holl architects
Prof. Parfitt ? Dr. Boothby Dr. Hanagan ? Dr.
Memari
Mr. Tim Bade Mr Ziad Jamaleddine
friends family
My AE classmates My friends my family
39
Questions?
Write a Comment
User Comments (0)
About PowerShow.com