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Ne w Mountain State s Re g ional OfficeNe w Mountain State s Re g ional OfficePhase II, Build ing BPhase II, Build ing B

Gre e le y, Colorad o to Salinas, California

Me gan D. HawkStructural Op tion

Photo Credit: HCC Photo Credit: HCC

Pre se ntation OutlinePre se ntation Outline

�� Overview of Original Building and Existing ConditionsOverview of Original Building and Existing Conditions�� Introduction to my InvestigationIntroduction to my Investigation�� Implications of New LocationImplications of New Location�� Redesign Considerations and AssumptionsRedesign Considerations and Assumptions�� Analysis of Alternative Lateral Load Resisting SystemsAnalysis of Alternative Lateral Load Resisting Systems�� Attachment of Mechanical Equipment and DuctworkAttachment of Mechanical Equipment and Ductwork�� Curtain Wall Material Selection for Seismic ResilienceCurtain Wall Material Selection for Seismic Resilience�� ConclusionsConclusions�� Credits and Acknowledgements Credits and Acknowledgements �� Questions?Questions?

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Build ing Ove rvie w & Existing Build ing Ove rvie w & Existing Cond itionsCond itions

�� One of two buildings in One of two buildings in Phase II of a threePhase II of a three--phase, phase, fourfour--building campus project building campus project for a major insurance for a major insurance companycompany

�� 44--story office building, plus story office building, plus basementbasement

�� 200,000 square feet200,000 square feet�� Currently located just Currently located just

outside of Greeley, outside of Greeley, ColoradoColorado

�� $29 million$29 million�� 18 month construction 18 month construction

scheduleschedule

Photo Credit: Holder Construction

Build ing Ove rvie w & Existing Build ing Ove rvie w & Existing Cond itionsCond itions

�� Features individual office Features individual office spaces, training classrooms, spaces, training classrooms, open office spaces, a small open office spaces, a small medical area, and a large medical area, and a large kitchen and cafeteriakitchen and cafeteria

�� Roughly 120’ x 330’ with Roughly 120’ x 330’ with typical bay sizes of 44’ x 20’ typical bay sizes of 44’ x 20’ and 35’ x 20’and 35’ x 20’

�� Project Team:Project Team:�� Ellerbe Becket, Ellerbe Becket,

Architect/EngineerArchitect/Engineer�� Holder Construction, Holder Construction,

Construction Construction ManagementManagement

Photo Credit: Holder Construction

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Proje ct Introduction & Prop osalProje ct Introduction & Prop osal

�� Originally designed to be built in Greeley, Colorado. Originally designed to be built in Greeley, Colorado. �� The owner is quite pleased with the results of this design The owner is quite pleased with the results of this design �� Owner has requested the building be used as a prototype for a Owner has requested the building be used as a prototype for a

future regional office campus in Salinas, California.future regional office campus in Salinas, California.

�� Location change requires an extensive investigation or redesign Location change requires an extensive investigation or redesign of of many of the building’s systems. many of the building’s systems.

�� The focus of this investigation:The focus of this investigation:�� Effects of the earthquakeEffects of the earthquake--induced forces the building must now induced forces the building must now

be designed to withstand. be designed to withstand.

Imp lications of Ne w LocationImp lications of Ne w Location

�� New codesNew codes�� New fire protection New fire protection

requirementsrequirements�� Energy efficiency requirements Energy efficiency requirements

(use of more efficient (use of more efficient materials)materials)

�� Maximization of solar benefitsMaximization of solar benefits�� New mechanical loadsNew mechanical loads�� Different foundation designDifferent foundation design�� Labor force analysisLabor force analysis�� Impacts on construction Impacts on construction

schedule and sequencingschedule and sequencing�� Cost impactsCost impacts�� Site requirementsSite requirements

�� Seismic attachment for lighting Seismic attachment for lighting and electrical systemsand electrical systems

�� Seismic attachment of the Seismic attachment of the brick veneerbrick veneer

�� Architectural design for Architectural design for contextual cohesivenesscontextual cohesiveness

�� Effects of salty air on buildingEffects of salty air on building�� Increased Capacity of Lateral Increased Capacity of Lateral

Load Resisting SystemLoad Resisting System�� Seismic Attachment of Seismic Attachment of

Mechanical SystemMechanical System�� Use of Unique Façade Use of Unique Façade

Elements to Avoid Breakage Elements to Avoid Breakage and Fallout in an Earthquakeand Fallout in an Earthquake

Adapting a building for a drastic location change such as this aAdapting a building for a drastic location change such as this affects ffects many aspects of the building’s design. Possible considerations many aspects of the building’s design. Possible considerations include:include:

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Se ismic Implications of New LocationSe ismic Implications of New Location

Seismic Load Effect Seismic Load Effect considers combined considers combined horizontal and vertical horizontal and vertical effects of an effects of an earthquake.earthquake.

Greeley, CO Salinas, CA Increase82.3 395.9 481%161.2 775.4 481%236.6 1138.3 481%236.4 739.9 313%716.5 3049.5 426%

Story Shear Forces

Story Force E Increase over Salinas Increase over Greeley395.9 1540 389% 1871%775.4 2182 281% 1354%1138.3 2796 246% 1182%739.9 1681 227% 711%

Story Shear Forces Considering Seismic Load Effect E

Orig inal Late ral Load Resisting Orig inal Late ral Load Resisting Syste m Ove rvie wSyste m Ove rvie w

�� Concentrically Braced Frames with Inverted VConcentrically Braced Frames with Inverted V--BracesBraces�� Wide Flange columns and beams, Square Tubes as cross bracesWide Flange columns and beams, Square Tubes as cross braces�� 7 braced frames in N7 braced frames in N--S directionS direction�� 4 braced frames in E4 braced frames in E--W directionW direction�� All frames are located in the building’s central coreAll frames are located in the building’s central core

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Re d e sign Consid e rations & Assump tionsRe d e sign Consid e rations & Assump tions�� Building is designed for a .4g earthquake, as prescribed by codeBuilding is designed for a .4g earthquake, as prescribed by codes. s. �� LIFE SAFETY is the main concern.LIFE SAFETY is the main concern.�� Beam depths are kept consistent with original design.Beam depths are kept consistent with original design.�� For this investigation, Member Shapes remain as they are in the For this investigation, Member Shapes remain as they are in the original original

design.design.�� All alternates use the original invertedAll alternates use the original inverted--V concentricallyV concentrically--braced frame designbraced frame design�� Interstory drift is limited to .00667h, 1/3 of the codeInterstory drift is limited to .00667h, 1/3 of the code--allowable interstory drift, allowable interstory drift,

to reduce nonto reduce non--structural damage in an earthquake.structural damage in an earthquake.�� For the alternate systems, drift is checked first, then strengthFor the alternate systems, drift is checked first, then strength..�� Roof and floor slabs are assumed to act as rigid diaphragms.Roof and floor slabs are assumed to act as rigid diaphragms.�� Redesign of the lateral system should not (minimally) interfere Redesign of the lateral system should not (minimally) interfere with the with the

existing building architecture and layout.existing building architecture and layout.�� Site Classification of D.Site Classification of D.�� Connection design would need to be considered, but is out of theConnection design would need to be considered, but is out of the scope of scope of

this project.this project.

Alte rnate Late ral Syste ms AnalysisAlte rnate Late ral Syste ms Analysis

�� Original lateral load resisting system failed miserably when Original lateral load resisting system failed miserably when subjected to the new lateral forces.subjected to the new lateral forces.

�� 10 alternate systems are investigated, all variations of the ori10 alternate systems are investigated, all variations of the original ginal design.design.

�� 5 basic ideas are explored:5 basic ideas are explored:�� Same number and layout of braced frames, larger membersSame number and layout of braced frames, larger members�� More braced frames, original member sizesMore braced frames, original member sizes�� More braced frames, larger member sizesMore braced frames, larger member sizes�� Combination of braced frames and moment frames, original Combination of braced frames and moment frames, original

member sizesmember sizes�� Combination of braced frames and moment frames, larger Combination of braced frames and moment frames, larger

member sizesmember sizes

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Alte rnate Late ral Syste ms AnalysisAlte rnate Late ral Syste ms AnalysisTrial ConclusionsTrial Conclusions

�� Only 2 trials were adequate for Interstory Drift.Only 2 trials were adequate for Interstory Drift.�� Both failed in strength analysis.Both failed in strength analysis.

�� Why?Why?�� Tube shapes cannot provide enough crossTube shapes cannot provide enough cross--sectional area to sectional area to

support the high axial forces.support the high axial forces.

�� What to do?What to do?�� Consider Alternate Designs!Consider Alternate Designs!

Alte rnate Late ral Syste ms AnalysisAlte rnate Late ral Syste ms AnalysisAlte rnate Brace d Frame De signsAlte rnate Brace d Frame De signs

�� Four additional alternates were (roughly) considered:Four additional alternates were (roughly) considered:�� Original Design, Replace Tubes with W14x211’sOriginal Design, Replace Tubes with W14x211’s�� XX--Braces using Double AnglesBraces using Double Angles�� Two Story XTwo Story X--Braces, WBraces, W--Shapes as BracesShapes as Braces�� Original Design, Add Moment Frame “Crutches”Original Design, Add Moment Frame “Crutches”

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Alte rnate Late ral Syste ms AnalysisAlte rnate Late ral Syste ms AnalysisAlte rnate Brace d Frame De signsAlte rnate Brace d Frame De signs

�� Four additional alternates were (roughly) considered:Four additional alternates were (roughly) considered:�� Original Design, Replace Tubes with W14x211’sOriginal Design, Replace Tubes with W14x211’s�� XX--Braces using Double AnglesBraces using Double Angles�� Two Story XTwo Story X--Braces, WBraces, W--Shapes as BracesShapes as Braces�� Original Design, Add Moment Frame “Crutches”Original Design, Add Moment Frame “Crutches”

�� Alternate Worthy of Further Investigation:Alternate Worthy of Further Investigation:�� Original Design, Replace Tubes with W14x211’s, Use Larger Original Design, Replace Tubes with W14x211’s, Use Larger

MembersMembers�� Interstory Drifts 81% less than original design, 67% less than Interstory Drifts 81% less than original design, 67% less than

the limit imposed for this analysisthe limit imposed for this analysis�� Almost all members are adequate for strengthAlmost all members are adequate for strength�� Cost EffectiveCost Effective�� Minimal Construction Impact, if anyMinimal Construction Impact, if any

Attachme nt of Me chanical Equip me ntAttachme nt of Me chanical Equip me nt

�� Why is Proper Attachment Important?Why is Proper Attachment Important?�� LIFE SAFETYLIFE SAFETY�� Reduces damage to equipment (consider small earthquakes)Reduces damage to equipment (consider small earthquakes)�� Reduces damage to other building componentsReduces damage to other building components�� Reduces downtime caused by seismic damageReduces downtime caused by seismic damage

�� Current AttachmentCurrent Attachment�� Vibration isolators are usedVibration isolators are used�� Inadequate for seismic restraintInadequate for seismic restraint�� Kinetics Noise Control products are usedKinetics Noise Control products are used

www.kineticsnoise.comwww.kineticsnoise.com

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Attachme nt of Me chanical Equip me ntAttachme nt of Me chanical Equip me nt

�� Kinetics Model FHSKinetics Model FHS�� For use with floorFor use with floor--mounted fans, pumps, mounted fans, pumps,

and air compressorsand air compressors�� Provides 1.0g (minimum) seismic Provides 1.0g (minimum) seismic

restraintrestraint�� Recommended for Noise and Vibration Recommended for Noise and Vibration

IsolationIsolation

�� Kinetics Model FLSSKinetics Model FLSS�� For use with floorFor use with floor--mounted cooling mounted cooling

towers, chillers, and boilerstowers, chillers, and boilers�� Provides 1.0g (minimum) seismic Provides 1.0g (minimum) seismic

restraintrestraint�� Recommended for Noise and Vibration Recommended for Noise and Vibration

IsolationIsolation

www.kineticsnoise.comwww.kineticsnoise.com

www.kineticsnoise.comwww.kineticsnoise.com

Attachme nt of Me chanical DuctworkAttachme nt of Me chanical Ductwork

�� Seismic Consideration Not Required For:Seismic Consideration Not Required For:�� Duct hung 12” or less from supporting structureDuct hung 12” or less from supporting structure�� Duct with crossDuct with cross--sectional area less than 6 square feetsectional area less than 6 square feet

www.kineticsnoise.comwww.kineticsnoise.com

�� Rigid Cable Restraint:Rigid Cable Restraint:�� For large ductsFor large ducts�� Wire Rope, Rod Wire Rope, Rod

Stiffener, Limit Stop, Stiffener, Limit Stop, and Isolation Hangerand Isolation Hanger

�� Interferes with plenum Interferes with plenum space space ---- Install after Install after plenum completionplenum completion

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Curtain Wall Mate rial Se le ctionCurtain Wall Mate rial Se le ction

�� ““EarthquakeEarthquake--induced damage to architectural glass components induced damage to architectural glass components often necessitates expensive repairs, exposes building contents often necessitates expensive repairs, exposes building contents to to weather, theft and vandalism, causes a disruption of activities weather, theft and vandalism, causes a disruption of activities within within the building, and presents a threat to life safety when glass fathe building, and presents a threat to life safety when glass falls from lls from a damaged wall system” (Memari 2002).a damaged wall system” (Memari 2002).

�� Four Alternate Glazing Four Alternate Glazing Systems are ConsideredSystems are Considered

Photo Credit: Holder ConstructionPhoto Credit: Holder Construction

Curtain Wall Mate rial Se le ctionCurtain Wall Mate rial Se le ction

�� Alternate Glazing Systems:Alternate Glazing Systems:�� Structural Silicone Adhesive as SealantStructural Silicone Adhesive as Sealant

�� Requires precise applicationRequires precise application�� Requires maintenanceRequires maintenance

�� EarthquakeEarthquake--Isolated Curtain Wall SystemIsolated Curtain Wall System�� ExpensiveExpensive�� Affects exterior appearanceAffects exterior appearance

�� Anchored Applied Film over Architectural GlassAnchored Applied Film over Architectural Glass�� Requires proper anchorage/applicationRequires proper anchorage/application�� Costly replacement is likelyCostly replacement is likely

�� Glass Panels with Rounded CornersGlass Panels with Rounded Corners

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Curtain Wall Mate rial Se le ctionCurtain Wall Mate rial Se le ction

�� Alternate Glazing Systems:Alternate Glazing Systems:�� Structural Silicone Adhesive as SealantStructural Silicone Adhesive as Sealant�� EarthquakeEarthquake--Isolated Curtain Wall SystemIsolated Curtain Wall System�� Anchored Applied Film over Architectural GlassAnchored Applied Film over Architectural Glass�� Glass Panels with Rounded Corners (1” Radius)Glass Panels with Rounded Corners (1” Radius)

�� Requires no modification to the originally designed wall Requires no modification to the originally designed wall systemsystem

�� Uses original window frames, etc.Uses original window frames, etc.�� Also practical for individual windowsAlso practical for individual windows�� Extremely costExtremely cost--effectiveeffective�� Very few construction concerns, if anyVery few construction concerns, if any�� No architectural impactNo architectural impact

ConclusionsConclusions

�� Lateral Load Resisting System:Lateral Load Resisting System:�� Use original design, but replace tube braces with wide flange Use original design, but replace tube braces with wide flange

column sectionscolumn sections

�� Mechanical Attachment:Mechanical Attachment:�� Use Kinetics products mentioned to restrain equipment and Use Kinetics products mentioned to restrain equipment and

ductworkductwork

�� Curtain Wall Material Selection:Curtain Wall Material Selection:�� Use original window framesUse original window frames�� Use 1” rounded corner windows in place of original rectangular Use 1” rounded corner windows in place of original rectangular

windowswindows

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Cre d its and Acknowle d g eme ntsCre d its and Acknowle d g eme nts

My FamilyMy Family

AE FacultyAE Faculty

Bill HeadleyBill HeadleyScott SheelerScott Sheeler

Friends at HomeFriends at Home

Penn State FriendsPenn State Friends

Fellow AE StudentsFellow AE Students

Que stions???Que stions???