住宅木结构建筑 第1部分：设计准则

AS 1684.1—1999 Residential timber-framed construction

Part 1

Design criteria

(Incorporating Amendment No.1)

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This Australian Standard was prepared by Committee TM/1, Timber Structures. It was approved on behalf of the Council of Standards Australia on 10 October 1999 and published on 5 December 1999.

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The following interests are represented on Committee TM/1:

• Australian Building Codes Board
• Australian Timber Importers' Federation
• Building Research Association of New Zealand
• CSIRO, Building, Construction and Engineering
• Curtin University of Technology
• Institution of Engineers, Australia
• Master Builders Australia
• Monash University
• New Zealand Forest Research Institute
• New Zealand Timber Industry Federation
• New Zealand Timber Suppliers Group
• Pine Australia
• Plywood Association of Australia
• Queensland Forestry Research Institute
• Timber Research and Development Advisory Council of Queensland
• University of Technology, Sydney

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This Standard was issued in draft form for comment as DR 97320.

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Australian Standard^TM

Residential timber-framed construction

Part 1: Design criteria

First published as AS 1684.1—1999.

Reissued incorporating Amendment No. 1 (February 2002).

COPYRIGHT

© Standards Australia International

All rights are reserved. No part of this work may be reproduced or copied in any form or by any means, electronic or mechanical, including photocopying, without the written permission of the publisher.

Published by Standards Australia International Ltd

GPO Box 5420, Sydney, NSW 2001, Australia

ISBN 0 7337 3040 X

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PREFACE

This Standard was prepared by the Joint Standards Australia/Standards New Zealand Committee TM/1, Timber Structures.

This Standard incorporates Amendment No. 1 (February 2002). The changes required by the Amendment are indicated in the text by a marginal bar and amendment number against the clause, note, table, figure, or part thereof affected.

This Standard is the result of a consensus of representatives on the Joint Committee that it be produced as an Australian Standard.

The objective of this Standard is to provide users with the design methods, assumptions and other design criteria, which have been used in the preparation of the Span Tables, uplift forces and racking pressures contained within AS 1684.2, AS 1684.3 and AS 1684.4.

Continued development of timber framing systems and the need to cater for a widening variety of materials and design conditions have led to a total revision of structural framing design. These developments include —

(a) provision for limit state design methods;

(b) revised/new structural grades for timber;

(c) provisions catering for open plan living—larger spans, wider openings and bigger rooms, which need a more rational approach to bracing design;

(d) special ‘engineered’ and fabricated timber products;

(e) recognition of a wider range of high wind and cyclonic design; and

(f) computer-aided design software for member sizes, bracing and tie-down.

This Standard is a companion publication to the following:

AS

1684	Residential timber-framed construction
1684.2	Part 2 Non-cyclonic areas
1684.3	Part 3 Cyclonic areas
1684.4	Part 4 Simplified—Non-cyclonic areas

The term ‘normative’ ‘has been used in this Standard to define the application of the appendix to which it applies, A ‘normative’ appendix is an integral part of a Standard.

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CONTENTS

Page

SECTION 1 SCOPE AND GENERAL

1.1 SCOPE AND APPLICATION 4

1.2 REFERENCED DOCUMENTS 4

1.3 OTHER METHODS 5

1.4 BASIS FOR DESIGN 5

1.5 DEFINITIONS 7

1.6 NOTATION 8

SECTION 2 DESIGN OF ROOF MEMBERS

2.1 ROOF BATTENS 10

2.2 RAFTERS 15

2.3 ROOF BEAMS—RIDGE OR INTERMEDIATE BEAMS 21

2.4 UNDERPURLINS 26

2.5 STRUTTING BEAMS 31

2.6 COUNTER STRUTTING BEAMS 35

2.7 COMBINED HANGING STRUTTING BEAMS 39

2.8 CEILING BATTENS 43

2.9 CEILING JOISTS 46

2.10 HANGING BEAMS 50

2.11 COUNTER BEAMS 54

2.12 VERANDAH BEAMS 58

SECTION 3 DESIGN OF WALL MEMBERS

3.1 POSTS 63

3.2 LOADBEARING WALL STUDS 66

3.3 WALL PLATES FOR LOADBEARING WALLS 74

3.4 LINTELS 80

SECTION 4 DESIGN OF FLOOR MEMBERS

4.1 FLOOR JOISTS 88

4.2 BEARERS 93

A1 SECTION 5 DETERMINATION OF UPLIFT FORCES

5.1 SCOPE AND GENERAL 99

5.2 DETERMINATION OF NET UPLIFT PRESSURES 99

SECTION 6 PRESSURES FOR DETERMINATION OF RACKING FORCES

6.1 SCOPE AND GENERAL 104

6.2 EQUIVALENT PRESSURES ON PROJECTED AREAS 106

APPENDICES

A CHARACTERISTIC BEAM SHEAR STRENGTHS FOR F-GRADES 110

B WIND CLASSIFICATIONS AND DYNAMIC GUST PRESSURES 111

C DESIGN OF OVERHANGS FOR PARALLEL BIRDSMOUTH NOTCHED RAFTERS 112

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SECTION 1 SCOPE AND GENERAL

1.1 SCOPE AND APPLICATION

1.1.1 Scope

This Standard sets out the design methods, assumptions and other criteria used in the preparation of the Span Tables, uplift forces and racking pressures contained within AS 1684.2, AS 1684.3 and AS 1684.4.

The design criteria apply for the preparation of design data for traditional timber-framed construction where the loading and performance requirements correspond to those for Class 1 and Class 10 buildings as defined by the Building Code of Australia.

This Standard should be read in conjunction with AS 1684.2, AS 1684.3 and AS 1684.4, the AS 1170 series, and AS 1720.1.

NOTE: Whilst this Standard may be used as a reference for the design of Class 10 buildings, less conservative levels of design for this building class may be permitted by building regulations and other Australian Standards.

1.1.2 Application

The design criteria contained herein may be used as a basis for the preparation of Span Tables and design data for structural wood products, having stress grades and sizes other than those included in AS 1684.2, AS 1684.3 and AS 1684.4 where the application and performance are claimed to be consistent with AS 1684.2, AS 1684.3 and AS 1684.4.

NOTE: The use of the design criteria contained in this Standard may provide evidence of satisfactory safety and serviceability performance.

1.2 REFERENCED DOCUMENTS

The following documents are referred to in this Standard:

AS
1170	Minimum design loads on structures (known as the SAA Loading Code)
1170.1	Part 1: Dead and live loads and load combinations
1170.2	Part 2: Wind loads
1170.3	Part 3: Snow loads
1170.4	Part 4: Earthquake loads
1684	Residential timber-framed construction
1684.2	Part 2: Non-cyclonic areas
1684.3	Part 3: Cyclonic areas
1684.4	Part 4: Simplified —Non-cyclonic areas
1720	Timber structures
1720.1	Part 1: Design methods

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