AS 1170.2—1989
Australian Standard SAA Loading Code
This is a free 6 page sample. Access the full version online.
Part 2: Wind loads
This Australian Standard was prepared by Committee BD/6, Loading on Structures. It was approved on behalf of the Council of Standards Australia on 19 December 1988 and published on 20 March 1989.
The following interests are represented on Committee BD/6: Association of Consulting Engineers, Australia Association of Consulting Structural Engineers, Australia Australian Clay Brick Association Australian Construction Services (Department of Administrative Services) Australian Council of Local Government Associations Australian Federation of Construction Contractors Australian Institute of Steel Construction Australian Mining Industry Council Building Management Authority, W.A. Bureau of Meteorology Bureau of Steel Manufacturers of Australia CSIRO, Division of Building, Construction and Engineering Department of Local Government, Qld Electricity Supply Association of Australia Engineering and Water Supply Department, S.A. James Cook University of North Queensland Master Builders’ Construction & Housing Association, Australia Monash University National Association of Australian State Road Authorities Public Works Department, N.S.W. University of Melbourne University of Newcastle Additional interests participating in preparation of Standard: Road Construction Authority This is a free 6 page sample. Access the full version online.
University of Sydney University of Western Australia
Review of Australian Standards. To keep abreast of progress in industry, Australian Standards are subject to periodic review and are kept up to date by the issue of amendments or new editions as necessary. It is important therefore that Standards users ensure that they are in possession of the latest ed ition, and any amendments thereto. Full details of all Australian Standards and related publications will be found in the Standards Australia Catalogue of Publications; this information is supplemented each month by the magazine ‘The Australian Standard’, which subscribing members receive, and which gives details of new publications, new editions and amendments, and of withdrawn Standards. Suggestions for improvements to Australian Standards, addressed to the head office of Standards Australia, are welcomed. Notification of any inaccuracy or ambiguity found in an Australian Standard should be made without delay in order that the matter may be investigated and appropriate action taken.
This Standard was issued in draft form for comment as DR 87163.
AS 1170.2—1989
Australian Standard Minimum design loads on structures (known as the SAA Loading Code)
This is a free 6 page sample. Access the full version online.
Part 2: Wind loads
First published as part of SAA Int. 350—1952. Revised and redesignated AS CA 34.2—1971. Revised and redesignated AS 1170.2 — 1973. Second edition 1975. Third edition 1981. Fourth edition 1983. Fifth edition 1989. Incorporating: Amdt 1 — 1991 Amdt 2 — 1993 Amdt 3 — 1993
PUBLISHED BY STANDARDS AUSTRALIA (STANDARDS ASSOCIATION OF AUSTRALIA) 1 THE CRESCENT, HOMEBUSH, NSW 2140 ISBN 0 7262 5485 1
AS 1170.2—1989
2
This is a free 6 page sample. Access the full version online.
PREFACE This Standard was prepared by the Standards Australia Committee for Loading on Structures to supersede AS 1170 — 1983, Minimum design loads on structures, Part 2 — Wind forces. This Standard is intended to be used for the determination of the minimum wind loads in structural design, and is in a limit states format. It provides a simplified procedure (Section 2) for the determination of wind loads on a limited range of small buildings and structures, and a detailed procedure (Sections 3 and 4) for determination of wind loads on a wide range of structures, varying from those less sensitive to wind action, to those for which dynamic response must be taken into consideration. It permits wind tunnel tests or similar determinations of wind loads on structures. Explanatory material for this Standard are given in Appendices C to F, which correspond to Sections 1 to 4. The Standards Australia Committee has considered exhaustive research and testing information from Australian and overseas sources in the preparation of this Standard with a view to reducing the design wind loads by the maximum extent consistent with safety. The design wind loads prescribed in this Standard are the minimum for the general cases. These will be circumstances arising in particular cases, which will result in additional loads requiring to be taken note of in the design of structures in those cases. Designers must be alert to the conditions to which their particular structure is exposed and must take note of all the provisions in clauses and notes under the clauses. This Standard differs from the previous Standard as follows: (a) Windspeeds are specified for the serviceability and ultimate strength/stability limit states, and for permissible stress design. (b) Return periods and windspeed contours (isopleths) have been deleted. (c) Regional boundaries have been included (boundaries of the tropical cyclone regions are slightly modified). (d) Direct shielding allowance is separately identified and extended. (e) A more rational system of multipliers for wind speed and external pressures is provided. (f) Methods of calculating wind loads on cantilevered roofs, attached canopies, awnings, carports, circular cross-sections, such as bins, silos and tanks, and lattice towers have been added. Existing data on pressure and force coefficients have been revised in the light of recent research. (g) Dynamic analysis has been expanded (replaces Annex: ‘Notes on Wind Forces on Tall Buildings’ in the previous edition). (h) References to other publications are listed numerically at the end of this document. (i) Statements expressed in mandatory terms in Notes to tables and figures are deemed to be requirements of this Standard. Notwithstanding the general copyright provisions applicable to all Australian Standards as detailed below, this Standard contains intellectual material provided by another party and permission to reproduce that material may be conditional on an appropriate royalty payment to Standards Australia, or the other party, or both. Details of the clauses applicable and the right to reproduce them either in printed or electronic form can be obtained from the Head Office of Standards Australia. Copyright STANDARDS AUSTRALIA Users of Standards are reminded that copyright subsists in all Standards Australia publications and software. Except where the Copyright Act allows and except where provided for below no publications or software produced by Standards Australia may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing from Standards Australia. Permission may be conditional on an appropriate royalty payment. Requests for permission and information on commercial software royalties should be directed to the head office of Standards Australia. Standards Australia will permit up to 10 percent of the technical content pages of a Standard to be copied for use exclusively in-house by purchasers of the Standard without payment of a royalty or advice to Standards Australia. Standards Australia will also permit the inclusion of its copyright material in computer software programs for no royalty payment provided such programs are used exclusively in-house by the creators of the programs. Care should be taken to ensure that material used is from the current edition of the Standard and that it is updated whenever the Standard is amended or revised. The number and date of the Standard should therefore be clearly identified. The use of material in print form or in computer software programs to be used commercially, with or without payment, or in commercial contracts is subject to the payment of a royalty. This policy may be varied by Standards Australia at any time.
3
AS 1170.2—1989
This is a free 6 page sample. Access the full version online.
CONTENTS Page
SECTION 1. SCOPE AND APPLICATION 1.1 SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 APPLICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 DESIGN PROCEDURES—SIMPLIFIED OR DETAILED 1.4 DESIGN REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . 1.5 DETERMINATION OF WIND LOADS . . . . . . . . . . . . . 1.6 DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 NOTATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
4 4 4 4 4 5 6
SECTION 2. SIMPLIFIED PROCEDURE 2.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 LIMITATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 BASIC PRESSURES (p′) . . . . . . . . . . . . . . . . . . . . . . . 2.5 MULTIPLYING FACTORS . . . . . . . . . . . . . . . . . . . . . 2.6 FATIGUE LOADING . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 SERVICEABILITY DESIGN LOADS . . . . . . . . . . . . . . 2.8 FARM BUILDINGS AND TEMPORARY STRUCTURES
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . . .
9 9 10 10 13 17 17 17
SECTION 3. DETAILED PROCEDURE: STATIC ANALYSIS 3.1 LIMITATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 GUST WIND SPEED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 DYNAMIC WIND PRESSURE (q z ) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4 FORCES (F) AND PRESSURES (pz ) ON ENCLOSED BUILDINGS, FREE ROOFS AND WALLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 FORCES ON EXPOSED STRUCTURAL MEMBERS . . . . . . . . . . . . . . 3.6 FATIGUE LOADING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23 33 35
SECTION 4. DETAILED PROCEDURE: DYNAMIC ANALYSIS 4.1 APPLICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 HOURLY MEAN WIND SPEED . . . . . . . . . . . . . . . . . 4.3 DYNAMIC WIND PRESSURE (qz ) . . . . . . . . . . . . . . . . 4.4 PROCEDURE AND DERIVATION . . . . . . . . . . . . . . .
. . . .
36 36 42 42
......
48
. . . . .
. . . . .
53 59 61 62 77
REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
90
INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
93
. . . .
. . . .
. . . .
. . . .
. . . .
APPENDICES A ADDITIONAL PRESSURE COEFFICIENTS . . . . . . . . . . . . . . . B SECTIONAL DRAG FORCE AND FORCE COEFFICIENTS AND ASPECT RATIO CORRECTION FACTORS . . . . . . . . . . . . . . . . C EXPLANATORY MATERIAL TO SECTION 1 . . . . . . . . . . . . . D EXPLANATORY MATERIAL TO SECTION 2 . . . . . . . . . . . . . E EXPLANATORY MATERIAL TO SECTION 3 . . . . . . . . . . . . . F EXPLANATORY MATERIAL TO SECTION 4 . . . . . . . . . . . . .
COPYRIGHT
. . . .
. . . .
. . . . .
. . . .
. . . . .
. . . .
. . . . .
. . . .
. . . . .
18 18 23
AS 1170.2—1989
4
STANDARDS AUSTRALIA Australian Standard Minimum design loads on structures Part 2: Wind loads
This is a free 6 page sample. Access the full version online.
SECTION 1. SCOPE AND APPLICATION 1.1 SCOPE. This Standard sets out procedures for determining design wind speeds and wind loads to be used in structural design of all buildings and components of buildings, bridges (minimum design wind speed only), and other structures subjected to wind. For bridges, the design wind loads shall be determined in accordance with the AUSTROADS Bridge Design Code. Major offshore structures remote from the coast and transmission lines are not covered, nor are the effects of tornadoes which are special-event winds. The design wind loads for structures containing high risk contaminants, such as some nuclear or biological materials is considered outside the scope of this Standard. This Standard does not attempt to account for possible future climatic changes. 1.2 APPLICATION. This Standard applies to structures, other than bridges, designed to Australian Standards using both limit state and permissible stress design rules. 1.3 DESIGN PROCEDURES — SIMPLIFIED OR DETAILED. 1.3.1 Simplified procedure. For the determination of wind loads on a limited range of small buildings and structures, including domestic buildings, a simplified procedure is given in Section 2 with limitations given in Clause 2.2. Simplified and detailed procedures shall not be mixed. (See Paragraph C1.3.1 of Appendix C.) 1.3.2 Detailed procedure — static and dynamic analysis. For the determination of wind loads on a wide range of structures, detailed procedures are given in Section 3 (Static analysis) and Section 4 (Dynamic analysis). These structures vary from those less sensitive to wind action to those in which dynamic response must be taken into consideration. The dynamic analysis shall be undertaken for the calculation of overall forces for any structure with both a height-(or length)-to-breadth ratio greater than five and the first mode frequency is less than 1 Hz. (See Paragraph C1.3.2 of Appendix C.) 1.4 DESIGN REQUIREMENTS. 1.4.1 General. Wind loads associated with any limit state or permissible stress design requirement, which is relevant to the safe and proper functioning of the
structure or its components, shall be determined from the appropriate clauses in this Standard. 1.4.2 Stability limit state. Wind loads acting alone or in combination with other loads, which cause failure or overturning of the structure as a whole, uplift or sliding, shall be calculated using ultimate limit states design wind speeds (V u). 1.4.3 Strength limit state. Wind loads acting on a structure and its components, which are required to be withstood without failure during the life of the structure, shall be calculated using ultimate limit states design wind speeds (V u). 1.4.4 Ultimate limit states. For the purpose of this Standard, stability and strength limit states are together called ultimate limit states. 1.4.5 Serviceability limit state. Serviceability limit state wind speeds (V s) are given to calculate wind loads acting on a structure and its components for serviceability limit states, such as excessive deflection, cracking and vibration. 1.4.6 Permissible stress design procedure. Where an Australian Standard has adopted a permissible stress design procedure, the wind loads acting on a structure or its components shall be calculated using permissible stress design wind speeds (V p). (See Paragraph C1.4 of Appendix C.) 1.5 DETERMINATION OF WIND LOADS. 1.5.1 Methods of determination of wind loads. Wind loads on a structure or part of a structure shall be determined by one or more of the following: (a) The applicable clauses of this Standard. (b) Reliable references used consistently with the clauses of this Standard. (c) Reliable data on wind speed and direction. The use of uncorrected anemometer data is not permitted. (d) As an alternative to the methods outlined in Clauses 3.2.3 and 4.2.3, the use of a detailed probability analysis for the effects of wind direction is allowed. (e) Wind tunnel or similar tests carried out for a specific structure or reference to such tests on a similar structure (see Clauses 1.5.2. and 1.5.3), together with applicable clauses of this Standard. (See Paragraph C1.5.1 of Appendix C.)
COPYRIGHT
This is a free 6 page sample. Access the full version online.
AS 1170.2-1989 Minimum design loads on structures (known as the SAA Loading Code) - Wind loads
The remainder of this document is available for purchase online at www.saiglobal.com/shop
SAI Global also carries a wide range of publications from a wide variety of Standards Publishers:
Click on the logos to search the database online.
