ISO/DIS 22156

Bamboo -- Structural design

Bambou -- Conception des structures

Standards Content (sample)

DRAFT INTERNATIONAL STANDARD
ISO/DIS 22156
ISO/TC 165 Secretariat: SCC
Voting begins on: Voting terminates on:
2020-07-06 2020-09-28
Bamboo — Structural design
Bambou — Conception des structures
ICS: 91.080.20
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 22156:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2020
---------------------- Page: 1 ----------------------
ISO 22156:####(X)
ISO/DIS 22156:2020(E)
Contents

Foreword ................................................................................................................................................................ vi

Scope ................................................................................................................................................................. 1

Exceptions....................................................................................................................................................... 1

Normative References ................................................................................................................................ 1

Terms and Definitions ................................................................................................................................ 2

Symbols and Abbreviated Terms ........................................................................................................... 4

Basic Requirements of Design ................................................................................................................. 7

General ............................................................................................................................................................. 7

Design Methodology.................................................................................................................................... 7

Susceptibility to Splitting .......................................................................................................................... 7

Redundancy ................................................................................................................................................... 8

Non-redundant structural members .............................................................................................. 8

Redundant structural members ....................................................................................................... 8

Serviceability Considerations.................................................................................................................. 8

Service Classes .............................................................................................................................................. 8

Service Class 1 ......................................................................................................................................... 9

Service Class 2 ......................................................................................................................................... 9

Service Class 3 ......................................................................................................................................... 9

Durability ........................................................................................................................................................ 9

Use Classes ............................................................................................................................................ 10

Resistance to Corrosion of Metallic Elements .......................................................................... 10

Effects of Elevated Temperature ......................................................................................................... 10

Maintenance, Inspectability and Replacement Considerations ............................................... 11

Seismic Force Reduction Factor for Bamboo Structures ...................................................... 11

Alternate Design Methodologies ................................................................................................... 11

Partial Safety Factor Design (PSFD) or Load and Resistance Factor Design (LRFD)

Methodology ......................................................................................................................................... 11

Experience from Previous Generations ...................................................................................... 11

Design by Testing ................................................................................................................................ 12

Member Component and Material Properties ................................................................................ 12

General .......................................................................................................................................................... 12

Characteristic Material and Component Properties .................................................................... 12

Allowable Member Design Capacity ................................................................................................... 13

Allowable Design Strength .................................................................................................................... 14

Culm Geometry for Use with Allowable Design Strength ..................................................... 15

Component Flexural Stiffness ............................................................................................................... 15

Modulus of Elasticity ................................................................................................................................ 16

Structural Modelling Bamboo Structures ........................................................................................ 16

Flexural Members (Beams) ................................................................................................................... 17

COPYRIGHT PROTECTED DOCUMENT

General .......................................................................................................................................................... 17

© ISO 2020

Multiple Culm Flexural Members ........................................................................................................ 17

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

Bracing Requirements for Multiple Culm Flexural Members ............................................. 17

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

Flexural Member Capacity ..................................................................................................................... 18

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester. Flexural Capacity Determined from Component Capacity .................................................. 18

ISO copyright office Flexural Capacity Determined from Bending Strength ......................................................... 19

CP 401 • Ch. de Blandonnet 8

Calculation of Deflection ........................................................................................................................ 19

CH-1214 Vernier, Geneva

Flexural Stiffness Determined from Component Properties .............................................. 19

Phone: [phone]
Fax: [phone]

Flexural Stiffness Determined from Material and Geometric Properties ...................... 20

Email: [e-mail]
Website: www.iso.org
Published in Switzerland
̹ʹͲʹͲ–ŽŽ”‹‰Š–•”‡•‡”˜‡† ‹‹‹
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/DIS 22156:2020(E)
Contents

Foreword ................................................................................................................................................................ vi

Scope ................................................................................................................................................................. 1

Exceptions....................................................................................................................................................... 1

Normative References ................................................................................................................................ 1

Terms and Definitions ................................................................................................................................ 2

Symbols and Abbreviated Terms ........................................................................................................... 4

Basic Requirements of Design ................................................................................................................. 7

General ............................................................................................................................................................. 7

Design Methodology.................................................................................................................................... 7

Susceptibility to Splitting .......................................................................................................................... 7

Redundancy ................................................................................................................................................... 8

Non-redundant structural members .............................................................................................. 8

Redundant structural members ....................................................................................................... 8

Serviceability Considerations.................................................................................................................. 8

Service Classes .............................................................................................................................................. 8

Service Class 1 ......................................................................................................................................... 9

Service Class 2 ......................................................................................................................................... 9

Service Class 3 ......................................................................................................................................... 9

Durability ........................................................................................................................................................ 9

Use Classes ............................................................................................................................................ 10

Resistance to Corrosion of Metallic Elements .......................................................................... 10

Effects of Elevated Temperature ......................................................................................................... 10

Maintenance, Inspectability and Replacement Considerations ............................................... 11

Seismic Force Reduction Factor for Bamboo Structures ...................................................... 11

Alternate Design Methodologies ................................................................................................... 11

Partial Safety Factor Design (PSFD) or Load and Resistance Factor Design (LRFD)

Methodology ......................................................................................................................................... 11

Experience from Previous Generations ...................................................................................... 11

Design by Testing ................................................................................................................................ 12

Member Component and Material Properties ................................................................................ 12

General .......................................................................................................................................................... 12

Characteristic Material and Component Properties .................................................................... 12

Allowable Member Design Capacity ................................................................................................... 13

Allowable Design Strength .................................................................................................................... 14

Culm Geometry for Use with Allowable Design Strength ..................................................... 15

Component Flexural Stiffness ............................................................................................................... 15

Modulus of Elasticity ................................................................................................................................ 16

Structural Modelling Bamboo Structures ........................................................................................ 16

Flexural Members (Beams) ................................................................................................................... 17

General .......................................................................................................................................................... 17

Multiple Culm Flexural Members ........................................................................................................ 17

Bracing Requirements for Multiple Culm Flexural Members ............................................. 17

Flexural Member Capacity ..................................................................................................................... 18

Flexural Capacity Determined from Component Capacity .................................................. 18

Flexural Capacity Determined from Bending Strength ......................................................... 19

Calculation of Deflection ........................................................................................................................ 19

Flexural Stiffness Determined from Component Properties .............................................. 19

Flexural Stiffness Determined from Material and Geometric Properties ...................... 20

© ISO 2020 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/DIS 22156:2020(E)

Long Term Deflections ......................................................................................................................20

Axial Load Carrying Members ...............................................................................................................20

General ..........................................................................................................................................................20

Compression Member Effective Length .............................................................................................21

Lateral Restraint of Compression Members ..............................................................................21

Compression Capacity..............................................................................................................................22

Compression Capacity from Geometric and Material Properties ......................................22

Crushing Capacity................................................................................................................................22

Buckling Capacity ................................................................................................................................22

Tension Capacity ........................................................................................................................................23

Tension Capacity from Component Capacity ............................................................................23

Tension Capacity from Geometric and Material Properties ................................................23

Combined Axial and Flexural Loads ...................................................................................................23

Joints and Splices .......................................................................................................................................24

General ....................................................................................................................................................24

Design Properties by Complete Joint Testing ...........................................................................24

Design Properties by Component Capacities ............................................................................24

Allowable Joint Design Capacity ....................................................................................................25

Joint Stiffness ........................................................................................................................................25

Ductility of Joints .................................................................................................................................25

Robustness Against Culm Splitting ...............................................................................................26

Radial Clamping to Resist Splitting ...............................................................................................26

Splices joints .........................................................................................................................................26

Requirements for Non-bamboo Components of Joints ..........................................................26

Metallic Components of Joints ........................................................................................................26

Joints Utilising Flowable Infill Material (Grouted Joints) .....................................................27

Lashing ....................................................................................................................................................27

Mechanical and Proprietary Joint Systems ................................................................................27

End Bearing Capacity of Bamboo Culms .....................................................................................27

Circumferential Bearing Capacity of Bamboo Culms .............................................................28

Joints Having Through Culm Wall Dowels .................................................................................29

Capacity of Single Dowel ...........................................................................................................30

Requirements for Dowels .........................................................................................................31

Tension Forces on Dowel Joints .............................................................................................31

Trusses ..........................................................................................................................................................31

Shear Panels (Walls) ................................................................................................................................32

General ....................................................................................................................................................32

Openings in Panels .............................................................................................................................32

Loads ........................................................................................................................................................33

Out-of-plane Loads .............................................................................................................................33

In-plane Loads ......................................................................................................................................34

Gravity Loads ........................................................................................................................................35

Determination of Design Strengths ..............................................................................................35

Fire Resistance ...........................................................................................................................................35

Structural Grading ....................................................................................................................................35

Quality Assessment and Control ..........................................................................................................36

Annex A (informative) – Bases of Provisions in this International Standard ..............................37

A.1 Bamboo Species ..........................................................................................................................................37

A.2 Culm Dimensions .......................................................................................................................................37

Annex B (informative) – Durability and Preservation Recommendations ..................................38

iv © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/DIS 22156:2020(E)

B.1 General .......................................................................................................................................................... 38

B.2 Recommendations for Designing Durable Bamboo Structures ................................................ 38

B.3 Bamboo Preservatives ............................................................................................................................. 39

Annex C (informative) – Examples of Seismic and Alternative Design Factors .......................... 41

C.1 – Seismic Force Reduction Factors for Bamboo Structures ........................................................ 41

C.2 – Partial Safety Factor Design (PSFD) or Load and Resistance Factor Design (LRFD) ...... 41

Annex D (informative) – Examples and Classification of Bamboo Connections and Joints ... 42

Annex E (informative) – Design of LCBF Components to Satisfy Requirements of 12 ............. 46

E.1 General........................................................................................................................................................... 46

E.2 Requirements of LCBF Components .................................................................................................... 46

E.2.1 Wall Matrix ............................................................................................................................................... 46

E.2.2 Render ........................................................................................................................................................ 47

E.2.3 Render Reinforcement ......................................................................................................................... 47

E.2.4 Vertical members (studs) .................................................................................................................... 48

E.2.5 Bracing ....................................................................................................................................................... 48

E.2.6 Head and Sole Plates ............................................................................................................................. 48

Bibliography ....................................................................................................................................................... 49

© ISO 2020 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/DIS 22156:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO

collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any

patent rights identified during the development of the document will be in the Introduction and/or on

the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the World

Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 165, Timber Structures

This second edition cancels and replaces the first edition (ISO 22156:2004), which has been technically

revised.
The main changes compared to the previous edition are as follows:

— adoption of design equations for material or component capacities for both members and joints

— adoption of service classes and specific consideration of susceptibility to splitting

— addition of Light Cement Bamboo Frame (LCBF) construction

— addition of informative Annexes addressing durability and representative details for connections

and LCBF construction
— removal of use of bamboo for reinforcing concrete or soil

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
vi © ISO 2020 – All rights reserved
---------------------- Page: 6 ----------------------
ISO/DIS 22156:2020(E)
Introduction

This standard provides a means of structural design for one- and two-storey building structures using

full-culm round bamboo poles as the primary vertical and horizontal structural load resisting systems.

This standard addresses connection design, light cement bamboo frame shear panel design, and

addresses issues of durability. Informative Annexes provide means of achieving design and performance

goals in these areas.
© ISO 2020 – All rights reserved vii
---------------------- Page: 7 ----------------------
ISO/DIS 22156:2020(E)
Bamboo — Structural Design
Scope

This International Standard applies to the design of bamboo structures whose primary load bearing

structure is made of round bamboo or shear panel systems in which the framing members are made from

round bamboo (12).

Except as indicated in 12, this International Standard applies to one- and two-storey residential, small

commercial or institutional and light industrial buildings not exceeding 7 m in height.

This International Standard is concerned only with requirements for mechanical resistance,

serviceability and durability of bamboo structures.

This International Standard permits an allowable load-bearing capacity design (ACD) and/or allowable

stress design (ASD) approach for the design of bamboo structures. Allowable load-bearing capacity and

allowable stress approaches may be used in combination in the same structure.

This International Standard additionally recognises design approaches based on partial safety factor

design (PSFD) and/or load and resistance factor design (LRFD) methods (5.11.1), previous established

experience (5.11.2), or documented ‘design by testing’ approaches (5.11.3).
Other requirements, such
...