1、Thermal performance of buildings - Thermal design of foundations to avoid frost heave BS EN IS0 L3793:2001 The European Standard EN IS0 137932001 has the status of a British Standard ICs 91.120.10; 93.020 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW STD-BSI BS EN IS0 l13793
2、-ENGL 2OOL W Lb24bb9 090bb78 726 M BS EN IS0 13793:2001 Amd.No. This British Standard, having been prepared under the direction of the Sector Committee for Buiiduig and Cid Engineering, was published under the authority of the Standards Committee and comes into effect on 15 May 2001 Date Comments Q
3、BSI 05-2001 ISBN O 580 36063 6 National foreword This British Standard is the official English language version of EN IS0 137932001. It is identical with IS0 137932001. The UK participation in its preparation was entrusted by Technical Committee WO, Energy performance of materials, components and bu
4、ildings, to Subcommittee B/540/1, European Standards for thermal insuiation, which has the responsibility to: - aid enquirers to understand the text; - present to the responsible internationavEuropean committee any enquiries on the interpretation, or proposals for change, and keep the UK interests i
5、nformed; - monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an a
6、nnex which lists nomative references to international publications with their corresponding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Corres
7、pondence Index“, or by using the “Find“ facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not
8、 of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside hnt cover, the EN title page, pages 2 to 48, an inside back cover and a back cover. The BSI copynght notice displayed in this document indicates when the document was last issued. Ame
9、ndments issued since publication - - STD.BS1 BS EN IS0 13793-ENGL 2OOL m 1624669 0906679 662 EUROPEAN STANDARD EN IS0 13793 NORME EUROPENNE EUROPISCHE NORM March 2001 ICs 91.020; 91.120.00 English version Thermal performance of buildings - Thermal design of foundations to avoid frost heave (IS0 1379
10、3:2001) Performance thermique des btiments - Conception thermique des fondations pour viter les pousses dues au gel (IS0 13793:2001) Wrmetechnisches Verhalten von Gebuden - Wrmetechnische Bemessung von Gebudegrndungen zur Vermeidung von Frosthebung (IS0 13793:2001) This European Standard was approve
11、d by CEN on 7 July 2000. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standa
12、rds may be obtained on application to the Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the
13、 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kin
14、gdom. EUROPEAN COMMITEE FOR STANDARDIZATION EUROPISCHES KOMITEE FR NORMUNG COMITE EUROPEEN DE NORMALISATION Management Centre: rue de Stassart, 36 8-1050 Brussels Q 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN IC0 13793:200
15、1 E Page 2 EN IS0 13793:2001 Contents Foreword Introduction 1 2 3 4 5 6 7 8 9 10 Scope Normative references Definitions, symbols and units Design principles Material properties Climatic data Foundation depth greater than frost depth in undisturbed ground Slab-on-ground floors for heated buildings Su
16、spended floors for heated buildings Unheated buildings Annex A (normative) Definition and calculation of freezing index Annex B (normative) Numerical calculations Annex C (normative) Design data for clab-on-ground floors based on O “C criterion Annex D (informative) Frost susceptibility of the groun
17、d Annex E (informative) Worked examples Annex ZA (normative) Normative references to International Standards and Annex ZB (informative) Informative references to International Standards and Bibliography corresponding European publications corresponding European publications 3 4 5 5 6 9 10 11 12 13 2
18、1 26 30 34 38 41 43 46 47 48 Page 3 EN IS0 13793:2001 Foreword The text of EN IS0 13793:2001 has been prepared by Technical Committee CENTTC 89 “Thermal performance of buildings and building components“, the secretariat of which is held by SIS, in collaboration with Technical Committee ISO/TC 163 “T
19、hermal insulation“. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2001, and conflicting national standards shall be withdrawn at the latest by September 2001. References to Internation
20、al Standards that have also been published as European Standards are given in normative annex ZA, which is an integral part of this European Standard. Annexes A, B and C form an integral part of IS0 13793. Annexes D and E are for information only. According to the CENKENELEC Internal Regulations, th
21、e national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United King
22、dom. STD-BSI BS EN IS0 l3793-ENGL 2001 W Lb24bb7 090bbB2 157 Page 4 EN IS0 13793:2001 Introduction Frost heave is the deformation of a building due to ice lenses in the ground below it, which can occur when soil freezes under the foundations or other structural members in contact with the soil. This
23、 is relevant to the design of building foundations in climates where the depth of penetration of frost into the ground may exceed the minimum foundation depth necessary for structural reasons. Not all types of soil are susceptible to frost heave (this is discussed in annex D). The risk of frost heav
24、e can be avoided in various ways. One is to have foundations deep enough so as to be below the frost penetration depth. Thus, special design procedures for frost heave are not necessary for buildings with basements extending more than the frost penetration depth below ground level (except to ensure
25、the use of suitable backfill material that will not adfreeze to the basement wall). Another possibility is to remove the frost-susceptible soil down to a depth below the frost penetration depth, and replace it with material that is non-susceptible to frost before constructing the foundations. A thir
26、d option is to insulate the foundations so as to avoid frost penetrating below the foundations. In cold climates the latter option is frequently the most economic as it allows shallower foundations, and this standard gives methods for determining the width, depth, thermal resistance and placement of
27、 insulation in the foundation region in order to reduce the risk of frost heave to a negligible level. In unheated buildings the heat available from the building itself is less than with heated buildings, and more perimeter insulation is needed to protect the foundations. The procedures in this stan
28、dard are essentially those that have been used in the Nordic countries over many years, and have been found to be satisfactory in practice in preventing frost heave. They are based on the results of dynamic computer calculations, which took account of the annual temperature cycle, the heat capacity
29、of the ground, the latent heat of freezing of water, etc., and which have been validated by experimental data from actual constructions. The standard is concerned with ensuring that the ground below the foundation (if frost-susceptible) does not become frozen. In permafrost areas (annual average tem
30、perature less than O OC), the appropriate design may, by contrast, be based on maintaining the ground fully frozen for the whole year. That involves quite different solutions that are not considered in this standard. - STD.BS1 BS EN IS0 13793-ENGL 200L = Lb24bb9 090bb3 093 Page 5 EN IS0 13793:2001 1
31、 Scope This standard gives simplified procedures for the thermal design of building foundations so as to avoid the occurrence of frost heave. It applies to foundations on frost-susceptible ground, and includes buildings with both slab-on-ground floors and suspended floors. It covers heated and unhea
32、ted buildings, but other situations requiring frost protection (for example roads, water pipes in the ground) are not included. The standard is not applicable to cold stores and ice rinks. The standard applies in climates where the annual average air temperature is above O OC, but does not apply in
33、permafrost areas where the annual average air temperature is below O OC. 2 Normative references This European Standard incorporates, by dated or undated references, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are
34、 listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references, the latest editions of the publication referred to applies (including amendments)
35、. IS0 6946 Building components and building elements - Thermal resistance and thermal transmittance - Calculation method IS0 7345 Thermal insulation - Physical quantities and definitions IS0 10211-1 Thermal bridges in building construction - Heat flows and surface temperatures - Part 1: General calc
36、ulation methods IS0 10456 Building materials and products - Procedures for determining declared and design thermal values Page 6 EN IS0 13793:2001 3 Definitions, symbols and units 3.1 Terms and definitions For the purposes of this standard, the terms and definitions in IS0 7345 and the following app
37、ly. 3.1.1 slab on ground floor floor construction directly on the ground over its whole area 3.1.2 suspended floor floor construction in which the floor is held off the ground, resulting in an air void between the floor and the ground NOTE This air void, also called underfloor space or crawl space,
38、may be ventilated or unventilated, and does not form pari of the habitable space. 3.1.3 vertical edge insulation insulation placed vertically against the foundation internally and/or externally, or within the foundation itself 3.1.4 ground insulation insulation placed horizontally (or nearly so) bel
39、ow ground, external to the building NOTE See Figure 1. 3.1.5 freezing index 24 times the sum of the difference between 0C and daily mean external air temperature, accumulated on a daily basis over the freezing season (including both positive and negative differences) 3.1.6 freezing season period dur
40、ing which the mean daily external air temperature remains less than O“C, together with any freezinghhawing periods at either end of this period if they result in net freezing 3.1.7 frost depth depth of penetration of frost into the ground 3.1.8 foundation depth depth of foundation below the outside
41、ground level NOTE If the foundations are put on a layer of well-drained material that is non-susceptible to frost, the thickness of such a layer may be included in the foundation depth. STD.BSI ES EN IS0 L3773-ENGL 2001 W Lb24bb7 090bb85 bb Symbol Quantity Page 7 EN IS0 13793:2001 Unit 3.1.9 frost-s
42、usceptible soil soil of a type which may cause frost heave forces when frozen as part of the ground width of ground insulation, measured from outer limit of footing width of ground insulation at corner width of ground insulation along wall bg bgc b“, 3.1.1 O floor insulation position height of lower
43、 surface of the floor insulation layer above external ground surface m m m NOTE If there is no insulation in the floor this quantity is measured from the floor surface. HO Ht HtC 3.2 Symbols and units The following is a list of the principal symbols used. Other symbols are defined where they are use
44、d within the text. maximum frost depth in undisturbed, snow-free ground m foundation depth for walls m foundation depth for corners m h L, f “ IB I width (smaller dimension) of building Im I floor insulation position m length of corner insulation (measured along external surface of wall) m m2-W ther
45、mal resistance of floor construction (average value over the outer 1 m of floor) thermal resistance of vertical edge insulation m2.W gw - e, 4.m I Fd I design freezing index I K-h I thermal resistance of ground insulation along wall annual average external air temperature average internal air temper
46、ature in month m m2.W “C “C I Fn I freezing index which statistically is exceeded once in a period of n years I K.h I I4 I depth of vertical edge insulation Im I I !4 I thermal resistance of ground insulation I m2.W I I Qc I thermal resistance of ground insulation at corner I m2.W I Page 8 EN IS0 13
47、793:2001 a) Lightweight concrete foundation wall with ground insulation li2 c) Concrete foundation wall with ground insulation and internal vertical edge insulation rr 1 II e) Raf construction with ground insulation and vertical edge insulation Key 1 Ground insulation 3 Non frost-susceptible soil 2
48、4 b) Floor slab with edge beam d) Concrete foundation wall with external . f) Raft construction over a bed of crushed stones (h 0,6 m, either undertake numerical calculations in accordance with annex B or use the procedures for unheated buildings (clause 1 O). 8.3.3 Thermal resistance of floor slab
49、The thermal resistance of the floor construction, f, is the total thermal resistance between the floor surface and the soil. It includes any insulation layers above, below or within it, together with that of any floor covering. If the thermal resistance of the floor construction varies over its area, take Rf as the average value over the outer 1 m of floor. The foundation depths and frost insulation specified in this clause apply to slabs with Rf not exceeding 5 m2.W. If Rf 5 m2.W, either undertake numerical calculations in accordance with a
