james dean baker - pennsylvania state university...james dean baker alcoa corporate center 201...

JAMES DEAN BAKERJAMES DEAN BAKERSTRUCTURAL OPTIONSTRUCTURAL OPTION

ALCOA CORPORATE CENTERALCOA CORPORATE CENTER

201 ISABELLA STEET201 ISABELLA STEET

James Dean BakerJames Dean Baker ALCOA Corporate CenterALCOA Corporate Center201 Isabella Street, Pittsburgh PA201 Isabella Street, Pittsburgh PA

Architectural EngineeringArchitectural EngineeringStructural OptionStructural Option

PRESENTATION OUTLINEPRESENTATION OUTLINEIntroductionExisting ConditionsStructural Existing ConditionsDesign Goals and CriteriaSuspension DesignConnectionsCost Analysis & Schedule ImpactsConstructability ProcessDaylighting ControlsDesign Results and RecommendationsConclusion



~ Design Team ~~ Design Team ~OWNERS:OWNERS:

ARCHITECT:ARCHITECT:

ENGINEERS:ENGINEERS:

GENERAL GENERAL CONTRACTORS:CONTRACTORS:

Aluminum Company of America

The Design Alliance

Atlantic Engineering Service (STRUCTURAL)

Dodson Engineering (MECHANICAL)

Hornfleck Engineering (ELECTRICAL)

Turner Construction

I N T R O D U C T I O NI N T R O D U C T I O N




LOCATIONLOCATION

77thth and 9and 9thth St. Bridges St. Bridges bookend the buildingbookend the building

Along the Allegheny RiverAlong the Allegheny River

North Shore of PittsburghNorth Shore of Pittsburgh

EXISTING CONDITIONS



Occupancy: Office Space, Company HeadquartersOccupancy: Office Space, Company Headquarters

MidMid--Rise Structure, 6 StoriesRise Structure, 6 Stories

236,200 sq. ft. of Flexible Office Space236,200 sq. ft. of Flexible Office Space

Below Grade Parking for 180 Vehicles Below Grade Parking for 180 Vehicles

Total Cost of 67 million dollarsTotal Cost of 67 million dollars

Completed in July of 1998Completed in July of 1998

ALCOA CORPORATE CENTERALCOA CORPORATE CENTER EXISTING CONDITIONSEXISTING CONDITIONS

Building Information



Typical Floor Plan:Typical Floor Plan:




STRUCTURAL SYSTEMSSTRUCTURAL SYSTEMS

FOUNDATION:FOUNDATION:FLOORING SYSTEMS:FLOORING SYSTEMS:SUPERSTRUCTURE :SUPERSTRUCTURE :

ROOF:ROOF:

CONNECTIONS:CONNECTIONS:

MOMENT FRAMES:MOMENT FRAMES:

BRACED FRAMES:BRACED FRAMES:

1400 Auger Cast Friction Piles

6” composite floor slab with a raised floor plenum

Steel Moment Frame (office Section)

Steel Frame with Braced Frames (supporting area)

Glass ceiling with structural steel framing

Full Moment connections throughout the office area

Office section of the building, full penetration welds

Lateral resisting system mainly in north side of the structure



Existing ConditionsExisting Conditions

Lateral System LayoutBraced Frames:

Types: I, II, III, IV

Stiffness:

I: 19.2 k/in

II: 19.2 k/in

III: 20.4 k/in

IV: 111.0 k/in

Moment Frames:

Type: I

Stiffness: 55.6 k/in

TYPE IV

TYPE III

TYPE II

TYPE III

TYPE I

MOMENT FRAMES

TYPE I

TYPE I



DESIGN GOALSDESIGN GOALS

Add an Exposed Roof Truss SystemAdd an Exposed Roof Truss System•• Support the Exterior of the Office AreaSupport the Exterior of the Office Area

Remove Full Moment ConnectionsRemove Full Moment ConnectionsAdd Pin Type ConnectionsAdd Pin Type ConnectionsEstablish Structurally FeasibleEstablish Structurally FeasibleConstructability and CostConstructability and CostImprove Lighting ControlsImprove Lighting Controls



Typical Floor LayoutTypical Floor Layout

Examples of the Examples of the

Areas to be SuspendedAreas to be Suspended



EXTERIOR BEAMSEXTERIOR BEAMSOffice SectionOffice Section

Beams:Beams:•• W 18 x 35 (typ.)W 18 x 35 (typ.)•• W 24 x 55 (typ.)W 24 x 55 (typ.)

ConnectionsConnections•• Shear Type (inner)Shear Type (inner)•• Seat Angles (outer)Seat Angles (outer)



Suspension System OptionsSuspension System Options

Truss SystemsTruss SystemsCable TensionCable Tension

4 Symmetrical Spans4 Symmetrical Spans

Two Large SpansTwo Large Spans

Several Shorter SpansSeveral Shorter Spans



SUSPENSION BRIDGESUSPENSION BRIDGETruss TypeTruss Type

Original Columns:Original Columns:New Columns:New Columns:Original Connections:Original Connections:•• Full MomentFull Moment

Proposed Connections:Proposed Connections:•• Shear Shear •• WeldsWelds

Hangars: W12 x 30 (top)Hangars: W12 x 30 (top)W10 x 19 (bottom)W10 x 19 (bottom)



SUSPENSION BRIDGESUSPENSION BRIDGETruss TypeTruss Type

Truss Type :Truss Type :Back to Back Channels: MC6 x 18Back to Back Channels: MC6 x 18

Plate Welded Connections: 3/8” weldsPlate Welded Connections: 3/8” welds

Gusset Plate Connections: 1” thick platesGusset Plate Connections: 1” thick plates

Bottom Chord: W36 x 245Bottom Chord: W36 x 245

Extended Columns: W12 x 83Extended Columns: W12 x 83



SUSPENSION BRIDGESUSPENSION BRIDGECable Tension TypeCable Tension Type

Original Columns: W 12 x 72New Columns: W 12 x 83Cable Connections: Clamp TypeCable Sizing: 7 Compact 0.6” diameter bundles of 270 ksi wiresBuckling Difficulties in the columns

Recommendation: Not Viable due to Aesthetics, and Story Connection difficulties

OVERVIEWOVERVIEW



Truss LocationsTruss Locations



Truss ConfigurationTruss Configuration



ConnectionsConnections

Truss ConnectionsTruss Connections

Welded Gusset Plate ConnectorsWelded Gusset Plate Connectors

12” Longitudinal Welds Required12” Longitudinal Welds Required

3/8” E 70 xx Fillet Weld3/8” E 70 xx Fillet Weld

Both Sides of Both ChannelsBoth Sides of Both Channels



ConnectionsConnections

Hanger ConnectionsHanger Connections

Connect to the W 24 x 55 Beams viaConnect to the W 24 x 55 Beams via

Angled Bolted ConnectionsAngled Bolted Connections

Beams are Spliced at 2 Story intervalsBeams are Spliced at 2 Story intervals

Ranging in Size fromRanging in Size from••W 12 x 30 in the Upper LevelsW 12 x 30 in the Upper Levels

••W 10 x 19 in the Bottom LevelsW 10 x 19 in the Bottom Levels

Sizes Decrease as they go down the Sizes Decrease as they go down the Building Due to Lower Cumulative Building Due to Lower Cumulative Loads on the HangersLoads on the Hangers



COST BENEFIT ANALYSISCOST BENEFIT ANALYSIS

RS Means, 2003RS Means, 2003-- $67,000 for Field Welds$67,000 for Field Welds-- $35,000 for Weld Inspections$35,000 for Weld Inspections+$53,700 for Crew & Crane+$53,700 for Crew & Crane= $48,000 = $48,000 SAVINGSSAVINGSPushes Schedule Back One WeekPushes Schedule Back One WeekSteel Erection Becomes Critical PathSteel Erection Becomes Critical Path



INITIAL SCHEDULEINITIAL SCHEDULE



FINAL SCHEDULEFINAL SCHEDULE



CONSTRUCTABILITYCONSTRUCTABILITY

PHASE ONEPHASE ONE PHASE TWOPHASE TWO

•Friction Piles

•Foundations

•Sub Level

•Columns

•Inner Beams

•North Side

•Truss Placement

•Build Back Down the Outside, Connecting



LIGHTING CONTROLSLIGHTING CONTROLSLightscape Rendering of the Daylighting in the Main Office AreasLightscape Rendering of the Daylighting in the Main Office Areas

Use of Open Loop Photo Sensors which Sense Daylight and ElectricUse of Open Loop Photo Sensors which Sense Daylight and Electric LightLight

Proportional ControllersProportional Controllers



LIGHTING CONTROLSLIGHTING CONTROLS

Proportional ControllersProportional Controllers••Produce a Voltage that is Inversely Proportional to the DetectedProduce a Voltage that is Inversely Proportional to the Detected LightLight

••Perform By Dimming the Electric Lights in a Linear Relationship Perform By Dimming the Electric Lights in a Linear Relationship According to SettingsAccording to Settings

Zoning of the Office SpacesZoning of the Office Spaces••Two Zones in the Office AreaTwo Zones in the Office Area

••Group Fixtures Run Parallel to the WindowsGroup Fixtures Run Parallel to the Windows

••Separate Control for Each Zone (outer & inner)Separate Control for Each Zone (outer & inner)

Features of ControlFeatures of Control

••Independent BehaviorIndependent Behavior

••Read their own ZoneRead their own Zone

••Target IlluminationTarget Illumination



DESIGN RESULTSDESIGN RESULTS

Floor: Floor: Full Moment Connections are Removed. Camber must be Increased tFull Moment Connections are Removed. Camber must be Increased to 5.25” for o 5.25” for

the 60 ft. interior office beamsthe 60 ft. interior office beams

Roof: Roof: Remains Largely Unchanged, Structurally. Columns are held at W Remains Largely Unchanged, Structurally. Columns are held at W 12 x 83. Span 12 x 83. Span Beams on Roof Remain W 36 x 245Beams on Roof Remain W 36 x 245

Suspension Systems: Suspension Systems: Symmetrical Dual Channel Truss Placed on Roof to Suspend Symmetrical Dual Channel Truss Placed on Roof to Suspend the Exterior of the Structurethe Exterior of the Structure

Lighting: Lighting: Controls Selected for Power Savings Controls Selected for Power Savings DuringDuring Elevated Day Light TimesElevated Day Light Times

Cost: Cost: Modest SavingsModest Savings

Foundations: Foundations: Remain UnchangedRemain Unchanged



FINAL RECOMMENDATIONSFINAL RECOMMENDATIONS

Structural: Owners ConsentStructural: Owners ConsentI Recommend to build it to Pay Homage to the Bridges of the I Recommend to build it to Pay Homage to the Bridges of the City of PittsburghCity of PittsburghConstructability Timing Becomes CriticalConstructability Timing Becomes Critical



THANK YOUTHANK YOU

ALL OF THE AE FACULTY AND STAFFALL OF THE AE FACULTY AND STAFFFRIENDSFRIENDSFAMILY FAMILY ATLANTIC ENGINEERING SERVICE PERSONNELATLANTIC ENGINEERING SERVICE PERSONNEL

JULES AND JEFFJULES AND JEFF--FRY FOR COMING OUT TO SEE THIS PRESENTATION. FRY FOR COMING OUT TO SEE THIS PRESENTATION. MUCH LOVE TO ALL THE PEEPS WHO PUT UP WITH MY HECTIC DAYS OF EXHMUCH LOVE TO ALL THE PEEPS WHO PUT UP WITH MY HECTIC DAYS OF EXHAUSTION.AUSTION.

I’D LIKE TO OPEN THE FLOOR TOI’D LIKE TO OPEN THE FLOOR TO

QUESTIONSQUESTIONSPLEASE PLEASE

james dean baker - pennsylvania state university...james dean baker alcoa corporate center 201...

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