British Code BS 6399 1995 Part 2 Code of Practice for Wind Loads for Buildings 1

  • View
    215

  • Download
    0

Embed Size (px)

Text of British Code BS 6399 1995 Part 2 Code of Practice for Wind Loads for Buildings 1

  • 8/20/2019 British Code BS 6399 1995 Part 2 Code of Practice for Wind Loads for Buildings 1

    1/92

    BRITISH STANDARD

    BS 6399:

    Part 2:1995

    Loading for

    buildings

    Part 2. Code of practice for wind loads

    -Jj.q++ Jy:c,:,, . ‘-j

    ~~ 2

    :T””’L3   4

      ..-....3 ,,,--

    NO COPYING WITHOUT BS1 PERMISSION EXCEPT AS PERMITTED BY COPYRIGHI LAW

  • 8/20/2019 British Code BS 6399 1995 Part 2 Code of Practice for Wind Loads for Buildings 1

    2/92

    BS6399:Part2: 1995

    This British Standard, having

    bee” prepared under the

    direction of the Building and

    Chil Engineering %ctor Board,

    was published tinder the

    authority of the Standards

    Bozwd and comes into effect on

    15 Ausust 1995

    0 BSI 1 295

    Nmt published (as CP 4)

    November 1944

    First revision (as CP 3:

    Chapter V) Ausust 1952

    %rfitd second revision (as CP3:

    Chapter V : Part 1)

    Becember 1967

    Completion of second revision

    (= CP 3: Chapter V : Part 2)

    July 1970

    Published as KS 6399: Fart 2:

    Au@st 1995

    The following 9S1 references

    relate ro the work on this

    sta”dati.

    Committee reference 9/525/ 1

    Draft for comment 91 I 16625 DC

    ISBN06S0 23651 X

    Committees responsible for this

    British Standard

    ‘rhe preparation of this Britiih Standard was entrusted by ‘lbchnical

    Committee B/525, Buildings and civil engineering structures, to Subcommittee

    B/525/1, Actions (loadings) and basis of desigrr, upon which the following

    bodies were represented:

    British Constructional Steelwork Association Ltd.

    British Iron arrdSteel Producem’ Association

    British Masonry Society

    Concrete Society

    Department of the Environment (Building Research Establishment)

    Department of the Environment (Property and Buifdings Directorate)

    Department of Trarrsport (Highways Agency)

    Institution of Structural En@reers

    National House-building Council

    Royal Institute of British Architects

    Steel Construction Institute

    Amendments issued since publication

    Amd. No. Date

    Text affected

    I

    I

  • 8/20/2019 British Code BS 6399 1995 Part 2 Code of Practice for Wind Loads for Buildings 1

    3/92

    BS6299:Part2:

    Contents

    Fage

    Committees responsible

    Inside front cover

    Foreword

    iv

    Section 1. General

    1.1

    1.2

    1.3

    1.4

    1.5

    1.6

    1.7

    1.8

    Scope

    Informative references

    Definitions

    Main symbols

    Outline of proceducc for calculating wirrd loads

    Dyrramic claasiiication

    Site exposure

    Choice of method

    1

    1

    1

    2

    3

    7

    7

    8

    Section 2. Standard method

    2.1 Standard wind loads

    9

    2.2 Standad wind speeds

    12

    2.3 Standard pressure coefficients

    20

    2.4 External pressure coefficients for walls

    20

    2.5 External pressure coefficients for roofs

    25

    2.6 Internal pressure coefficients

    39

    2.7 Pressure coefficients for elements

    41

    Section 3. Directional method

    3.1 Dwectional wind loads

    44

    3.2 Directional wind speeds

    46

    3.3 Dnctional pressure coefficients

    51

    3.4 Hybrid combinations of standard arrd dkectional methods

    72

    Annexes

    A (normative) Necessary pruviaions for wind tunnel testing

    73

    B (irrfOmative) Derivation of extreme wind information

    73

    C (informative) Dynamic augmentation

    75

    D (nonnative) PmbabiIity factor and seasonaf factor

    77

    E (informative) ‘l&rain categories and effective height

    79

    F (informative) Gust peak factor

    81

    ‘lhbles

    1

    2

    3

    4

    L

    6

    7

    8

    9

    10

    11

    12

    Buifding-type faCtOr&

    Dynamic pressure g= [in Pa)

    Valves of dwection factor S,j

    Factor .%,for standard methud

    ExcemaA pressure cucfficients Cw for verticaI walk

    Frictional drag coefficients

    External pressure Cw coefficients for walls of circulm-plan buildhrgs

    Extemaf pressure ceefficienta Cw for flat roofs of buiIdings

    External presarrc coefficients Cw for monOpirch mOfs Of buildin@

    External pressure coefficients C& for duopitch roofs of build@s

    External pressure coefficients Cw for hipped roofs of buildings

    Reduction factor for multi-bay roofs

    7

    9

    17

    20

    21

    25

    25

    26

    31

    31

    32

    35

    i

  • 8/20/2019 British Code BS 6399 1995 Part 2 Code of Practice for Wind Loads for Buildings 1

    4/92

    Dcr

    .s : - z :

    Page

    13 Net pressure coefficients CP for free-standing monopitch canopy roofs 36

    14 Net pre~um coefficients CP for free-standing duopitch canopy roofs

    15 Reduction factors for free-standing multi-bay camopy roofs

    16 Internal pressure coefficients CPi for enclosed build@s

    17 Internal pressure coefficients Cpi for buildings with dominant

    opmings

    HI Internal

    pressure coefficients Cpi for open-sided buildings

    19 Internal pressure coefficients Cpi for open-tOpped vertical ~lindem

    20 Net pressure coefficients CP for long elements

    21 Net pressure coefficients CP for free-standing W*

    22 Factom .SCind $

    23 A@stment factors I“c and Tt for sites in town terrain

    24 Gust peak factor gt

    25 Values of L, and .Sh

    26 External pressure coefficients Cp, for vertical walls of

    rectangular-plan buildings

    27 Reduction factom for zone A on verticaf walls of polygon&plan

    buildings

    28 External pressure coefficients CP, for vertical gable w~k adjacent tO

    non-vertical walls and roofs

    29 External pressure coefficients Cw for windward-facing nOn-vefiical

    walls

    30 ExtemaJ pressure coefficients Cw for flat roofs with sharp eaves

    31 Reduction factor for zones A to D, H to J and Q to S of flat roofs

    with parapets

    32 External pressure coefficients Cm for flat roofs with curved eaves

    33 External pressure coefficients Cw for flat roofs with mansard eaves

    34 External pressure coefficients CP, for pitched roof zones A to J

    35 Extemaf pressure coefficients CR for pitched roof zOnes K tO S

    36 External pressure coefficients Cw for additional zones T to Y of

    hipped roofs

    37 Intemaf pressure coefficients Cpj for open-sided buildings

    D. 1 Values of seasonal factor

    Figures

    1 Flowchart illustrating outline procedure 4

    2 Basic deftitions of building dimensions

    6

    3 Dynamic augmentation factor C,

    8

    4

    Size

    effect factor Ca of standard method

    11

    5 Definition of diagonal of loaded areas

    12

    6 Basic wind speed

    Vb

    (in rds) 13

    7 Definition of significant topography

    14

    8 Definition of topographic dimensions

    15

    9

    lbpogmphic location factors for hills and ridges

    16

    10 ‘f@ographic kxation factors for cliffs and escarpments 17

    11 Division of buildings by parts for lateral loads 19

    12 Key to wall pressure data 21

    13 Typical examples of buildhygs with m-entrant comers and recessed

    bays 22

    37

    37

    39

    40

    40

    40

    41

    42

    48

    49

    50

    51

    52

    .52

    54

    55

    59

    60

    60

    61

    63

    66

    70

    72

    78

    ii

  • 8/20/2019 British Code BS 6399 1995 Part 2 Code of Practice for Wind Loads for Buildings 1

    5/92

    Page

    14 Examples of flush irregular walls

    15 Key for walls of inset storey

    16 Key for flat roofs

    17 Key to cave details for flat roofs

    18 Key for inset stomy

    19 Key for monopitch roofs

    W Key for duopitch roofs

    21 Key for hipped roofs

    22 Key for mansard and multipitch roofs

    22 Key for multi-bay roofs

    24 Key for free-standing canopy roofs

    25 Reduction factor for length of elements

    26 Key for free-stamding walls

    27 Shelter factor for fences

    26 Key for signboards

    29 Wind directions for a rectarrgulm-plan building

    26 Key to overall load

    P

    31 Key for vertical walls of builrlii

    32 Key to vertical gable wrdls

    23 Key for walls of buildings with m-entrant comers

    24 Key for walls of buildings with recessed bays

    35 Key to general method for flat rcofs

    26 Examples of zones of flat roof of arbM’ary Plan shape

    37 Additional zones around inset storey

    28 Key for monopitch roofs

    39 Synrmetries for pitched roofs

    40 Key for duopitch roofs

    41 Key for hipped roofs

    42 Key to multi-bay roofs

    E. 1 Effective heights br towns

    F. 1 Gust peak factor gt

    L&t of references

    23

    24

    26

    27

    28

    29

    30

    33

    34

    35

    38