allison lamb structural emphasis april 16, 2003
DESCRIPTION
New Science Center. Lateral System Redesign. Allison Lamb Structural Emphasis April 16, 2003. Presentation Outline. Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations. Background. Project Team Owner - PowerPoint PPT PresentationTRANSCRIPT
Allison LambStructural Emphasis April 16, 2003
New Science CenterLateral System Redesign
Allison LambKutztown University
New Science Center April 16, 2003
Presentation Outline
Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations
Allison LambKutztown University
New Science Center April 16, 2003
Background
Project Team Owner
Pennsylvania System of Higher Education Architect
Stv Architects Engineer
Stv Incorporated
Allison LambKutztown University
New Science Center April 16, 2003
Background
Delivery Method Design – Bid – Build
Dates of Construction 3/18/02 – 10/3/04
Several Phase Project Addition
3/18/02 – Present Overall Cost
$16 million Addition Cost
$11.4 million
Allison LambKutztown University
New Science Center April 16, 2003
Background
Location Kutztown University
campus Berks County,
Pennsylvania Building Function
Academic Building Science Departments Classrooms, Labs, Offices
Allison LambKutztown University
New Science Center April 16, 2003
Background
Architecture Brick facade Large glass Atrium Floor Layout
Red – offices Green – Classrooms Blue – Labs Magenta – Vertical circulation Yellow – Storage/building systems Black – atrium space
First Floor
Second Floor
Third Floor
Fourth Floor
Allison LambKutztown University
New Science Center April 16, 2003
Presentation Outline
Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations
Allison LambKutztown University
New Science Center April 16, 2003
Existing Structural
Gravity System Composite Framing
5 in. Concrete 1 ½ in. composite metal deck 50 ksi Steel beams and girders 50 ksi Steel columns
Roof Framing Roof joists 50 ksi beams and girders
Allison LambKutztown University
New Science Center April 16, 2003
Existing Structural
Lateral System Steel moment frames
2 in E-W Direction 2 In N-S direction Typical Connection
Allison LambKutztown University
New Science Center April 16, 2003
Existing Structural
Foundations 4000 psi concrete rock bearing drilled
piers with grade beams in the unexcavated portion of the building
spread footings in the basement portion
Allison LambKutztown University
New Science Center April 16, 2003
Presentation Outline
Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations
Allison LambKutztown University
New Science Center April 16, 2003
Proposal
Replace current lateral system Redesign Criteria
lateral force resisting system must: be designed to resist the lateral loads perform to the required serviceability criteria
under the design loads lateral force resisting system must not:
compromise the architectural aesthetics and functionality of the building’s spaces
disrupt the other building systems be prohibitively expensive
Allison LambKutztown University
New Science Center April 16, 2003
Proposal
Alternative #1 incorporate braced frames into the
structure Alternative #2
create several frames with partially restrained connections
Alternative #3 some combination of braced frames
and partially restrained frames
Allison LambKutztown University
New Science Center April 16, 2003
Presentation Outline
Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Gravity System Realign columns into grid system for
more options Resize members using RAM
Check flexure, shear, deflection, composite action
Smaller member sizes Second Floor Vibration Issue
Leave second floor member sizes unchanged
Original Layout New Layout
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Lateral System Alternative #1 –
Braced Frames typical placement Architectural
repercussions Add a column
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Alternative #2 – PR Frames Use several frames and take advantage of
the stiffness in the PR connections
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Alternative #3 Use braced frames in East – West
direction and PR Frames in North – South Direction
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Braced Frames Initial member
sizes determined by gravity requirements
Checked with Ram using ASCE 7-95 lateral loads
Members increased to meet strength requirements
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Frames modeled in STAAD to determine stiffness
ASCE 7-98 Lateral Loads distributed by rigidity
Member sizes increased to meet strength and stiffness requirements under lateral loads including torsion
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Drift due to wind limited to H/400 Allowable 1.875” Actual 1.406”
Drift due to seismic limited to 2% of the story height below
LevelActual Drift
(inches)Story Drift
(inches)
Allowable Story Drift
(inches)
5(Roof) 1.113 0.306 5.08
4 0.807 0.349 3.52
3 0.458 0.307 3.52
2 0.151 0.151 2.88
LevelActual Drift
(inches)
Allowable Drift (inches)
Story Drift (inches)
Allowable Story Drift
(inches)
5(Roof) 1.406 1.875 0.409 0.635
4 0.997 1.240 0.439 0.440
3 0.558 0.800 0.353 0.440
2 0.205 0.360 0.205 0.360
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Final member sizes Columns - W14x109 Beams - W30x90 Braces - 2L5x5x7/8
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
PR Frames Method of Flexible wind connections or
type 2 with wind (ASD) Beams designed as simple beams Columns designed to provide frame stability connections designed to resist the factored
lateral loads and have sufficient ductility to accommodate the rotations
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Initial member sizes determined by flexible moment connection method
frames modeled in STAAD as FR and stiffness determined
Lateral Loads redistributed by rigidity
Member sizes increased to provide adequate strength and stiffness requirements
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Drift determined as per conservative British Wind-Moment Approach
Drift determined using FR connections, then multiplied by 1.5 to account for actual PR connections
Wind drift limited to H/400 Allowable total drift = 1.875” Actual total drift = 1.220”
Seismic Drift limited to 2 inchesLevelActual Drift
(inches)Allowable Drift
(inches)Story Drift
(inches)Allowable Story
Drift (inches)
5(Roof) 1.220 1.875 0.080 0.635
4 1.140 1.240 0.202 0.440
3 0.938 0.800 0.336 0.440
2 0.602 0.360 0.602 0.360
LevelActual Drift
(inches)Story Drift
(inches)
Allowable Story Drift
(inches)
5(Roof) 1.938 0.162 5.08
4 1.776 0.355 3.52
3 1.421 0.536 3.52
2 0.885 0.885 2.88
Allison LambKutztown University
New Science Center April 16, 2003
Redesign
Final Member sizes Beams W30x99 Columns W14x145
Connection Double Web Angle Top and Bottom Seat Designed to resist shear Moment-Rotation Characteristics determined Typical connection
Allison LambKutztown University
New Science Center April 16, 2003
Presentation Outline
Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations
Allison LambKutztown University
New Science Center April 16, 2003
Other Considerations
Foundations Changing layout of frames, adding
additional columns and relocating columns
Redesign for bearing, shear, and overturning
Architectural New column layout changes room sizes
slightly
Allison LambKutztown University
New Science Center April 16, 2003
Other Considerations
Mechanical System Changing some room sizes will affect
the mechanical load for those spaces Lighting System
Room size changes will affect the lighting layout
Allison LambKutztown University
New Science Center April 16, 2003
Other Considerations
Cost Comparison Gravity System
Redesign = total savings of $72,596.67 Lateral System
PR Frames = increase of $23,696.66 Braced Frames = Savings of $54,633.43
Allison LambKutztown University
New Science Center April 16, 2003
Presentation Outline
Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations
Allison LambKutztown University
New Science Center April 16, 2003
Fire Protection
Automatic wet sprinkler protection to provide 100% protection coverage
IBC 2000 Code Requirements Business Group B occupancy type Type IB construction
Building Element Fire Rating (hours)
Structural FrameIncluding columns, girders
2
Floor ConstructionIncluding supporting beams
2
Roof ConstructionIncluding Supporting beams, joists
1
Allison LambKutztown University
New Science Center April 16, 2003
Fire Protection
Floor Construction UL Design No. D902
4.5” concrete min. Spray applied fire
resistive materials None required for floor 1-1/16” inch to the
beams and girders
Allison LambKutztown University
New Science Center April 16, 2003
Fire Protection
Columns UL Design No. X501
Spray Applied Fire resistive materials
1 3/8” coating Glass Fiber Gauze 2 1/16” coats
Allison LambKutztown University
New Science Center April 16, 2003
Presentation Outline
Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations
Allison LambKutztown University
New Science Center April 16, 2003
Acoustical
300 seat auditorium/lecture hall Room Size
109 ft3 per person Preferred range 80–150 ft3 per person
Room Shape Sloped 5˚ Best sloped 7˚ or more
Allison LambKutztown University
New Science Center April 16, 2003
Acoustical
Room Materials Red - Gypsum Board Blue - Fabric-Wrapped
acoustical panels Magenta - Acoustical
ceiling tile Yellow - Wooden chair
rail Green - Pinch-pleated
drapery
Allison LambKutztown University
New Science Center April 16, 2003
Acoustical
Reverberation Times Calculation using sound absorption
properties of materials Optimal - less than 0.8s from 250 to 4000
Hz
Reverberation Times (s)
Conditions 125 Hz 500 Hz 4000 Hz
Fully Occupied 0.49 0.33 0.26
One-half Occupied
0.52 0.35 0.27
Allison LambKutztown University
New Science Center April 16, 2003
Presentation Outline
Background Existing Structural Proposal Redesign Other Considerations Fire Protection Acoustical Recommendations
Allison LambKutztown University
New Science Center April 16, 2003
Recommendations
Gravity System Consider redesigned member sizes but verify
vibration requirements Lateral System
Use braced frames in the east-West direction Use original moment frames in North-South
Direction Fire Protection
Choose system to meet minimum code requirements
Acoustical Consider increasing the slope of the room
Allison LambKutztown University
New Science Center April 16, 2003
acknowledgements
Thank you
Stu Rothenberger of STV Architects for all of the information that made thesis possible
All of my Friends and Family especially Mike, I couldn’t have done this without you
The AE Faculty for their expertise and help
Happy Birthday to me
Allison LambKutztown University
New Science Center April 16, 2003
Questions
Any Questions?
Allison LambKutztown University
New Science Center April 16, 2003
Background
Mechanical System Variable Volume System 8 AHUs handling 146,275 CFM Lab Spaces
Once Through Air Humidified
Other Spaces – 50% Outside Air, 50% Recirculated
650 Ton Chiller 650 Ton Cooling Tower Natural gas fired 143 HP Boiler
Allison LambKutztown University
New Science Center April 16, 2003
Background
Lighting System Interior lighting provided by fluorescent
lighting fixtures auditorium/lecture hall has fluorescent fixtures
for normal lighting and 75 watt incandescent fixtures for dimming
controlled by local switches throughout the building
Exit and emergency lighting connected to the emergency distribution system
exterior building lighting consists of metal halide fixtures
Allison LambKutztown University
New Science Center April 16, 2003
Background
Electrical System Splice into existing13.2kV campus distribution
feeder Interior unit substation transforms voltage to
208/120 volt service main power distribution is a 208/120 volt, 3
phase, 4 wire system emergency and standby power provided by a
natural-gas-fired engine generator