1、3Steel Design GuideServiceability DesignConsiderationsSecond Editionfor Steel Buildingscover DG3 revise.qxd 4/27/2004 8:58 AM Page 33Steel Design GuideServiceability DesignConsiderationsMICHAEL WEST AND JAMES FISHERComputerized Structural Design, Inc.Milwaukee, Wisconsinwith contributions fromLAWREN
2、CE G. GRIFFISWalter P. Moore and AssociatesAustin, TexasAMERICAN INSTITUTE OF STEEL CONSTRUCTION, INC.for Steel BuildingsSecond EditionCopyright 2003byAmerican Institute of Steel Construction, Inc.All rights reserved. This book or any part thereofmust not be reproduced in any form without thewritten
3、 permission of the publisher.The information presented in this publication has been prepared in accordance with recognizedengineering principles and is for general information only. While it is believed to be accurate,this information should not be used or relied upon for any specific application wi
4、thout com-petent professional examination and verification of its accuracy, suitability, and applicabilityby a licensed professional engineer, designer, or architect. The publication of the material con-tained herein is not intended as a representation or warranty on the part of the AmericanInstitut
5、e of Steel Construction or of any other person named herein, that this information is suit-able for any general or particular use or of freedom from infringement of any patent or patents.Anyone making use of this information assumes all liability arising from such use.Caution must be exercised when
6、relying upon other specifications and codes developed by otherbodies and incorporated by reference herein since such material may be modified or amendedfrom time to time subsequent to the printing of this edition. The Institute bears no responsi-bility for such material other than to refer to it and
7、 incorporate it by reference at the time of theinitial publication of this edition.Printed in the United States of AmericaFirst Printing: March 2004vPreface AcknowledgementsThis Design Guide is the second edition of AISC DesignGuide 3, which was originally titled Serviceability DesignConsiderations
8、for Low-Rise Buildings. The new title Ser-viceability Design Considerations for Steel Buildingsreflects the addition of information on tall buildings and thefollowing more general information:1. A review of steel building types, occupancies and ser-viceability design considerations related to each,
9、asapplicable.2. Revision to current editions of references.3. Information on ponding for roof design.4. Information on floors, including discussion regardingcambering beams and how deflection issues relate to theconstruction of concrete slabs.5. Revision of floor vibration information to follow AISC
10、Design Guide 11, Floor Vibrations Due to Human Activity(Murray and others, 1997).AISC would also like to thank the following people forassistance in the review of this Design Guide. Their com-ments and suggestions have been invaluable.Todd AlwoodHarry A. ColeCharles J. CarterCynthia J. DuncanTom Fer
11、rellLouis F. GeschwindnerJohn L. HarrisChristopher M. HewittLawrence KloiberJay W. LarsonRoberto LeonWilliam LiddyRonald L. MengCharles R. PageDavis ParsonsDavid T. RickerVictor ShneurWilliam T. SeguiEldon TippingThe authors wish to thank the Metal Building Manufactur-ers Association for its joint s
12、upport with AISC in the prepa-ration of the first edition of this Guide. viiTable of ContentsChapter 1Introduction 1Serviceability Requirements in the AISC Specification 1Storage/Warehouses 3Manufacturing3Heavy Industrial/Mill Buildings 3Mercantile/Shopping Malls4Health Care and Laboratory Facilitie
13、s 4Educational 4Office Buildings 4Parking Structures5Residential/Apartments/Hotels 5Assembly/Arenas 5Seismic Applications5Chapter 2Design Considerations Relative to Roofing7Ponding Stability7Roofing 9Membrane Roofs9Metal Roofs11Chapter 3Design Considerations Relative to Skylights13Chapter 4Design Co
14、nsiderations Relative to Cladding,Frame Deformation, and Drift 15Cladding-Structure Interaction 15Foundation-Supported Cladding for Gravity Loads15Frame-Supported Cladding at Columns 18Frame-Supported Cladding for GravityLoads Along Spandrels 19Special Considerations for Tall Buildings 19Chapter 5De
15、sign Considerations Relative to InteriorPartitions and Ceilings 21Support Deflection 21Flat and Level Floors 21Specifying Camber and Camber Tolerances22Maintaining Floor Elevation23Chapter 6Design Considerations Relative to Vibration/Acceleration 25Human Response to Vibration 25Machines and Vibratio
16、n 25Tall Building AccelerationMotion Perception 25Chapter 7Design Considerations Relative to Equipment 29Elevators 29Conveyors 29Cranes 29Mechanical Equipment 30References33AppendixSummary of Serviceability Considerations37DESIGN GUIDE 3, 2ND EDITION / SERVICEABILITY DESIGN CONSIDERATIONS FOR STEEL
17、BUILDINGS /1Serviceability is defined in the AISC Specification as “astate in which the function of a building, its appearance,maintainability, durability, and comfort of its occupants arepreserved under normal usage”. Although serviceabilityissues have always been a design consideration, changes in
18、codes and materials have added importance to these mat-ters. The shift to a limit-states basis for design is one example.Since 1986, both the AISC LRFD and AISC ASD Specifi-cations have been based upon the limit-states designapproach in which two categories of limit states are recog-nized: strength
19、limit states and serviceability limit states.Strength limit states control the safety of the structure andmust be met. Serviceability limit states define the functionalperformance of the structure and should be met. The distinction between the two categories centers on theconsequences of exceeding t
20、he limit state. The conse-quences of exceeding a strength limit may be buckling,instability, yielding, fracture, etc. These consequences arethe direct response of the structure or element to load. Ingeneral, serviceability issues are different in that theyinvolve the response of people and objects t
21、o the behaviorof the structure under load. For example, the occupants mayfeel uncomfortable if there are unacceptable deformations,drifts, or vibrations.Whether or not a structure or element has passed a limitstate is a matter of judgment. In the case of strength limits,the judgment is technical and
22、 the rules are established bybuilding codes and design specifications. In the case of ser-viceability limits, the judgments are frequently non-techni-cal. They involve the perceptions and expectations ofbuilding owners and occupants. Serviceability limits have,in general, not been codified, in part
23、because the appropri-ate or desirable limits often vary from application to appli-cation. As such, they are more a part of the contractualagreements with the owner than life-safety related. Thus, itis proper that they remain a matter of contractual agreementand not specified in the building codes.In
24、 a perfect world the distinction between strength andserviceability would disappear. There would be no prob-lems or failures of any kind. In the real world all designmethods are based upon a finite, but very small probabilityof exceedance. Because of the non-catastrophic conse-quences of exceeding a
25、 serviceability limit state, a higherprobability of exceedance is allowed by current practicethan for strength limit states.The foregoing is not intended to say that serviceabilityconcerns are unimportant. In fact, the opposite is true. Byhaving few codified standards, the designer is left to resolv
26、ethese issues in consultation with the owner to determine theappropriate or desired requirements. Serviceability problems cost more money to correct thanwould be spent preventing the problem in the design phase.Perhaps serviceability discussions with the owner shouldaddress the trade-off between the
27、 initial cost of the potentiallevel of design vs. the potential mitigation costs associatedwith a more relaxed design. Such a comparison is only pos-sible because serviceability events are by definition notsafety related. The Metal Building Manufactures Associa-tion (MBMA) in its Common Industry Pra
28、ctices (MBMA,2002) states that the customer or his or her agent must iden-tify for the metal building engineer any and all criteria sothat the metal building can be designed to be “suitable forits specific conditions of use and compatible with othermaterials used in the Metal Building System.” Never
29、theless,it also points out the requirement for the active involvementof the customer in the design stage of a structure and theneed for informed discussion of standards and levels ofbuilding performance. Likewise the AISC Code of StandardPractice (AISC, 2000) states that in those instances wherethe
30、fabricator has both design and fabrication responsibility,the owner must provide the “performance criteria for thestructural steel frame.”Numerous serviceability design criteria exist, but they arespread diversely through codes, journal articles, technicalcommittee reports, manufacturers literature,
31、 office stan-dards and the preferences of individual engineers. ThisDesign Guide gathers these criteria for use in establishingserviceability design criteria for a project.Serviceability Requirements in the AISC SpecificationThe LRFD Specification (AISC, 1999) lists five topics thatrelate to service
32、ability concerns. They are:1. camber2. expansion and contraction3. deflections, vibrations, and drift4. connection slip5. corrosionCamberCamber may or may not be a solution to a serviceabilityissue, and the authors have attempted to identify appropri-Chapter 1Introduction2 / DESIGN GUIDE 3, 2ND EDIT
33、ION / SERVICEABILITY DESIGN CONSIDERATIONS FOR STEEL BUILDINGSate and inappropriate use of camber in this Design Guide. Inmost instances, the amount of total movement is of concernrather than the relative movement from the specified floorelevation, in which case camber is not an appropriate solu-tio
34、n. There are, however, situations where camber is appro-priate, such as in places where it is possible to sight downthe under side of exposed framing.Expansion and ContractionExpansion and contraction is discussed to a limited extent.The goal of this Design Guide is to discuss those aspects ofprimar
35、y and secondary steel framing behavior as theyimpact non-structural building components. For many typesof low-rise commercial and light industrial projects, expan-sion and contraction in the limited context given above arerarely an issue. This does not mean that the topic of expan-sion and contracti
36、on is unimportant and, of course, theopposite is true. For large and/or tall structures, careful con-sideration is required to accommodate absolute and relativeexpansion and contraction of the framing and the non-struc-tural components.Connection SlipConnection slip has not been addressed explicitly
37、 in thisDesign Guide. However, it is the authors intent that the var-ious drift and deflection limits include the movements dueto connection slip. Where connection slip, or especially theeffect of accumulated connection slip in addition to flexuraland/or axial deformations, will produce movements in
38、excess of the recommended guidelines, slip-critical jointsshould be considered. Slip-critical joints are also required inspecific instances enumerated in Section 5 of the Specifica-tion for Structural Joints Using ASTM A325 or ASTM A490Bolts (RCSC, 2000). It should be noted that joints madewith snug
39、-tightened or pretensioned bolts in standard holeswill not generally result in serviceability problems for indi-vidual members or low-rise frames. Careful considerationshould be given to other situations.CorrosionCorrosion, if left unattended, can lead to impairment ofstructural capacity. Corrosion
40、is also a serviceability con-cern as it relates to the performance of non-structural ele-ments and must be addressed by proper detailing andmaintenance. The primary concerns are the control or elim-ination of staining of architectural surfaces and preventionof rust formation, especially inside assem
41、blies where it caninduce stresses due to the expansive nature of the oxidationprocess. Again, the solutions are proper detailing and main-tenance.Serviceability Requirements in ASCE 7ASCE 7-02, Minimum Design Loads for Buildings andOther Structures (ASCE, 2002) addresses serviceability inparagraph 1
42、.3.2 Serviceability as follows:“Structural systems, and members thereof, shall bedesigned to have adequate stiffness to limit deflec-tions, lateral drift, vibration, or any other deforma-tions that adversely affect the intended use andperformance of buildings and other structures.”ASCE 7-02 provides
43、 an appendix with commentary enti-tled Serviceability Considerations. While this appendix isnon-mandatory, it does draw attention to the need to con-sider five topic areas related to serviceability in the designof structures:deflection, vibration, and driftdesign for long-term deflectioncamberexpans
44、ion and contractiondurabilityThe ASCE 7 appendix introduction notes that “service-ability shall be checked using appropriate loads for the limitstate being considered.” The commentary to the Appendixprovides some suggestions with regard to loads and loadcombinations. For example, two load combinatio
45、ns are sug-gested for vertical deflections of framing members:D + LD + 0.5SThese are recommended for limit states “involving visu-ally objectionable deformations, repairable cracking orother damage to interior finishes, and other short termeffects.” For serviceability limit states “involving creep,
46、set-tlement, or other similar long-term or permanent effects,”the suggested load combination is:D + 0.5LWith regard to lateral drift, the commentary cites thecommon interstory drift limits of L/600 to L/400. The com-mentary also notes that an absolute interstory drift limit of3/8 in. (10 mm) may oft
47、en be appropriate to prevent damageto non-structural elements. This absolute limit may berelaxed if there is appropriate detailing in the non-structuralelements to accommodate greater drift. The commentaryprovides the following load combination for checkingshort-term effects:D + 0.5L + 0.7WThe reade
48、r is encouraged to refer to the appendix commen-DESIGN GUIDE 3, 2ND EDITION / SERVICEABILITY DESIGN CONSIDERATIONS FOR STEEL BUILDINGS /3tary, which provides additional insights into the issue of ser-viceability and an extensive list of references. This Guide will address the following serviceabilit
49、ydesign criteria:1. roofing2. skylights3. cladding4. interior partitions and ceilings5. vibrations6. equipmentMost of these criteria limit relative and absolute deflec-tion and, in the case of vibrations, place limits on the rangeof response and controls for the physical characteristics ofstructures and elements. Additionally, the presentation anddiscussion of a consistent loading and analysis approach isessential to these criteria. Without these three elements(load, analysis approach, and serviceability limit) a service-ability design criterion is useless.This Design Guide provides servi
