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1、DRAFT FOR DEVELOPMENT DD 7995:2003 Specification for temporary access platforms Performance and design requirements, and test methods ICS 53.020 ? Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:22:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD 7995:2003 Th
2、is Draft for Development was published under the authority of the Standards Committee and comes into effect on 3 December 2003 The following BSI references relate to the work on this Draft for Development Committee reference B/514/42 Draft for comment 01/104223 DC ISBN 0 580 42449 9 Committees respo
3、nsible for this Draft for Development The preparation of this Draft for Development was entrusted by Technical Committee B/514, Access and support equipment, to B/514/42, Access and working platforms, upon which the following bodies were represented: Forestry Commission Institution of Civil Engineer
4、s National Access and Scaffolding Contractors Association Timber Trades Federation Health and Safety Executive British Ladder Manufacturers Association Building Research Establishment Amendments issued since publication Amd. No.DateComments Licensed Copy: London South Bank University, London South B
5、ank University, Tue Dec 12 05:22:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD 7995:2003 BSI 3 December 2003 i Contents Committees responsibleInside front cover Forewordii Introduction5 1Scope1 2Normative references1 3Terms and definitions2 4Materials2 5General performance requirements2 6Structur
6、al performance requirements4 7Design requirements for assessment of platforms or platform units6 8Test methods7 9Marking15 10Information to be supplied15 Annex A (normative) Classification of non-standardized materials16 Annex B (normative) Loads and partial factors for design17 Annex C (normative)
7、Adjustment coefficients for test results18 Figure 1 Test for verifying slip resistance8 Figure 2a) Layout for platform robustness test12 Figure 2bi) End-on impact13 Figure 2bii) Oblique impact13 Figure 3 Test rig for resistance to unintentional displacement14 Table 1 Percentage of each load to be us
8、ed in combinations of loads5 Table 2 Test details for flammability test11 Table B.1 Partial safety factors for materials (M) not covered by British Standards17 Table B.2 Partial factors, F, to be applied to characteristic loads18 Licensed Copy: London South Bank University, London South Bank Univers
9、ity, Tue Dec 12 05:22:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD 7995:2003 ii BSI 3 December 2003 Foreword This Draft for Development has been prepared by a Task Group from Technical sub-committee B/514/42. It specifies requirements for the construction, performance and testing of temporary ac
10、cess platforms intended for use as part of a temporary access system. The requirements contained in this Draft for Development result from the best technical information available to the committee at the time of writing. This Draft for Development is intended for use by designers, engineers, scaffol
11、ding contractors and authorities having jurisdiction. Product certification/inspection/testing. Users of this Draft for Development are advised to consider the desirability of third-party certification/inspection/testing of product conformity with this Draft for Development. Appropriate conformity a
12、ttestation arrangements are described in BS EN ISO 9001. Users seeking assistance in identifying appropriate conformity assessment bodies or schemes may ask BSI to forward their enquiries to the relevant association. This publication is not to be regarded as a British Standard. It is being issued in
13、 the Draft for Development series of publications and is of a provisional nature because UK experience needs to be gained. It should be applied on this provisional basis, so that information and experience of its practical application may be obtained. A review of this Draft for Development will be c
14、arried out no later than 2 years after its publication. Notification of the start of the review period, with a request for the submission of comments from users of this Draft for Development, will be made in an announcement in the appropriate issue of Update Standards. According to the replies recei
15、ved, the responsible BSI committee will judge whether the Draft for Development can be converted into a British Standard or what other action should be taken. Observations which it is felt should receive attention before the official call for comments will be welcomed. These should be sent to the Se
16、cretary of BSI Technical sub-committee B/514/42 at British Standards House, 389 Chiswick High Road, London W4 4AL. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 19 and a back cover. The BSI copyright notice displayed throughout this documen
17、t indicates when the document was last issued. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:22:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD 7995:2003 BSI 3 December 2003 1 Introduction With most structures, an ability to support the loads that will be
18、applied during its working life is the governing criterion. For temporary access platforms, this is not always the case because, in addition: they are used in harsh environments; they are often not maintained; and they regularly receive rough treatment. Their design should recognize the implications
19、 of these adverse conditions. Consequently, access platforms require a robustness that ensures that, in the event of accidents or rough treatment, the damage will not be disproportionate to its cause. This robustness requires the careful design of each component to ensure that it is not too sensitiv
20、e to the effects of such incidental loads. In addition, the design of temporary access platforms should facilitate their fabrication, erection, use, dismantling and future maintenance. This Draft for Development is intended to cover all types of platform. It extends the relevant requirements of EN 1
21、2811-1 by providing additional requirements, and tests that are a means of verifying some of these requirements. 1 Scope This Draft for Development specifies requirements for performance and the basis for the design of temporary access platforms for general use. It forms an extension to EN 12811-1,
22、which specifies the basic requirements for six different load classes of access platform. This Draft for Development also specifies test methods. For materials not covered by an appropriate design standard, this Draft for Development contains information for their use. While the draft is principally
23、 about platforms and platform units, it also gives information on preventing their dislodgement. It considers both individual components and the assembled access area. Components conforming to this Draft for Development may be said to be a product in conformity with it. 2 Normative references The fo
24、llowing referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. BS 476-12:1991, Fire tests on building materials and st
25、ructures Part 12: Method of test for ignitability of products by direct flame impingement. BS 3212, Specification for flexible rubber tubing, rubber hose and rubber hose assemblies for use in LPG vapour phase and LPG/air installations. EN 12811-1, Temporary works equipment Scaffolds Part 1: Performa
26、nce requirements and general design. ISO 7892, Vertical building elements Impact resistance tests Impact bodies and general test procedures. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:22:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD 7995:2003 2 BSI 3
27、December 2003 3 Terms and definitions For the purposes of this Draft for Development, the following terms and definitions apply. NOTEThese definitions are not identical to those in EN 12811-1. 3.1 platform nominally horizontal surface on which a person can work and/or store materials necessary for t
28、he work, comprising a full width section of decking made up of a single component, or two or more platform units 3.2 platform unit single component which can form a platform, or part of a platform but is generally not wide enough to constitute a platform when used on its own 3.3 impact load load app
29、lied almost instantaneously 3.4 normal load load which can be expected to occur frequently during the service life of the platform NOTEThis includes the permanent and variable loads as defined in BS EN 1990. 3.5 accidental load impact load which can occur during the service life of a platform but wh
30、ich is infrequent 3.6 protruding connecting lug projecting piece forming part of a platform or platform unit which provides a connection with its supporting structure 4 Materials Where materials are covered by existing design standards, this draft requires the design of the platform to satisfy those
31、 requirements. NOTEAnnex A gives information on classifying and establishing design values for materials that may be used where no published data is available. When EN 12811-2 is approved, it will also give some information on materials. 5 General performance requirements 5.1 General Platforms and t
32、heir individual components shall be capable of supporting the imposed loads in all the combinations specified in 6.4. 5.2 Ergonomics 5.2.1 Weight The platform or the platform units shall be such that, during assembly, no operative is required to handle more than 25 kg. NOTEFurther advice on manual h
33、andling is given in “Manual handling” 1. 5.2.2 Centre of gravity Where the centre of gravity of any platform or platform unit is not within 5 % of the longer dimension of the geometrical centre of the platform, the centre of gravity shall be marked. NOTEThis is because it is sometimes assumed that t
34、he visual centre is the centre of gravity, which is not necessarily the case. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:22:52 GMT+00:00 2006, Uncontrolled Copy, (c) BSI DD 7995:2003 BSI 3 December 2003 3 5.2.3 Trips and falls It shall be possible for pe
35、rsons to walk on a platform without having to make conscious efforts to place their feet to avoid tripping, falling or knocking hazards. NOTE If the requirements of 5.4.1, 5.4.2, 5.4.3, 5.6 and 6.5 are met, this subclause will be deemed to be satisfied. 5.3 Safety in handling and erection 5.3.1 Surf
36、acing The surface and edges of platforms and individual components shall be free from edges and other imperfections that can cause injury to persons during handling. 5.3.2 Width Where a platform is made up of a number of individual platform units, the width of the individual platform units shall not
37、 be less than 200 mm. NOTEThe 200 mm limit is to provide an adequate space on which to stand. 5.4 The completed platform 5.4.1 Gaps The gaps between adjacent platforms or platform units shall not exceed 25 mm. NOTE Clearances between components should as far as possible follow the requirements given
38、 in BS EN 349. 5.4.2 Slots The width of slots in platform surfaces shall not exceed 25 mm, and the area shall not exceed 150 mm2. 5.4.3 Flatness Unloaded platforms or platform units shall be flat within 20 mm over any 3.0 m length. In addition, between adjacent units, there shall be no steps greater
39、 than 25 mm in any direction. 5.5 Resistance to environmental degradation Platforms and their support components shall be fabricated out of materials that have a calculatable resistance to environmental degradation during their intended design life. The calculated resistance shall be based on recogn
40、ized published data. NOTEThis resistance can be natural or can be provided by other recognized means. 5.6 Slip resistance Platforms shall have a slip resistant surface. The surface of the platform shall have a minimum coefficient of friction of 0.35 when in contact with rubber with an IRHD of 70, de
41、termined in accordance with the test method given in 8.3. 5.7 Security against unintentional displacement Platforms shall be secured against unintentional displacement so that they cannot be dislodged. NOTE 1It should not be possible to displace the platform, or its individual decking units, more th
42、an 25 mm horizontally. This requirement will be satisfied when, on completion of the test specified in 8.8, the load carrying capacity of the platform is not affected. Security against uplift by wind shall be verified by calculation, using a characteristic pressure of 770 N/m2. NOTE 2770 N/m2 will b
43、e sufficient for most situations. However, special consideration should be given in any location liable to greater pressure, for example, exposed north-westerly sites. Licensed Copy: London South Bank University, London South Bank University, Tue Dec 12 05:22:52 GMT+00:00 2006, Uncontrolled Copy, (c
44、) BSI DD 7995:2003 4 BSI 3 December 2003 5.8 Flammability Platforms shall be fire-resistant. This requirement will be satisfied if it is shown that when tested in accordance with 8.5 that the following are met: a) there is no transient ignition as defined in BS 476-12:1991, 2.2; b) there are no flam
45、ing droplets after flame removal; c) the flames do not reach any edge of the test specimen during application of the ignition source; and d) the spread of flame does not reach the edge of the test specimen at any point within the first 30 s after removal of the flame. 6 Structural performance requir
46、ements 6.1 General Vertical and horizontal loading requirements shall be as specified in EN 12811-1. NOTEThese include a small allowance for dynamic effects normally experienced and which treat it as an equivalent static load. In addition, this clause specifies tests for accidental loads, which repr
47、esent more severe conditions than those specified in columns 3 and 4 of Table 4 in EN 12811-1. Annex B of this Draft for Development gives the associated limit state partial factors associated with these cases. All loads are summarized in the following subclauses. 6.2 Vertical loads/actions 6.2.1 No
48、rmal loads Platforms shall be capable of supporting the loads for the appropriate class of load specified in column 2 of Table 4 in EN 12811- 1. Tests to verify conformity with static load requirements shall be in accordance with those prescribed in 8.4. NOTEEN 12811-1 specifies several different cl
49、asses of load. The load tests specified in 8.4.5.1a) and b) shall be carried out. To satisfy the requirements of 6.2.1, the platform or any individual platform unit: a) shall not, at the completion of the test in 8.4.5.1a), have a residual deflection, d1, which exceeds 10 % of the deflection under the maximum test load Fmax defined in 8.4.5.1; b) shall show no identifiable yielding, fracture (e.g. a crack beginning to spread), or separation of any part of the assembly a