BS 5507-1-1977 Methods of test for falsework equipment - Floor centres《脚手架设备试验方法 第1部分 可调钢梁》.pdf

1、BRITISH STANDARD BS 5507-1: 1977 Incorporating Amendment No. 1 Methods of test for Falsework equipment Part 1: Floor centres UDC 69.057.5:620.17BS5507-1:1977 This British Standard, having been prepared under the directionof the Builders Plant and Equipment Standards Committee, was published underthe

2、 authority of the Executive Board on 31August1977 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference PEB/1 Draft for comment 75/10230 DC ISBN 0 580 09875 3 Cooperating organizations The Builders Plant and Equipment Standards Committee, under whose direc

3、tion this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: British Mechanical Engineering Confederation Concrete Society Limited* Contractors Plant Association Department of the Environment, Building Res

4、earch Station* Federation of Civil Engineering Contractors Federation of Manufacturers of Construction Equipment and Cranes Health and Safety Executive* National Association of Scaffolding Contractors* National Federation of Building Trades Employers* Royal Institute of British Architects Truck and

5、Ladder Manufacturers Association The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Aluminium Federation British Steel Industry Confederation of British Industry

6、 Construction Health and Safety Group Construction Industry Training Board Department of the Environment (PSA) Incorporated Association of Architects and Surveyors Institution of Civil Engineers Institution of Municipal Engineers Institution of Structural Engineers Prefabricated Aluminium Scaffoldin

7、g Manufacturers Association Amendments issued since publication Amd. No. Date of issue Comments 5360 May 1989 Indicated by a sideline in the marginBS5507-1:1977 BSI 10-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 1 Scope 1 2 Reference 1 3 Principles 1 4 Test arrangem

8、ent and apparatus 2 5 Testing procedure 3 6 Interpretation 4 7 Test report 4 Appendix A Checking previously used floor centres 5 Appendix B Basic considerations 5 Appendix C Uses of test report 6 Figure 1 Test 1 (for bending moment and deflection) 6 Figure 2 Test 2 (for shear and support forces) 7 F

9、igure 3 Test 3 (for interaction forces at lapped joint) 8 Figure 4 Test 4 (for intermediate propping force) 8 Figure 5 Cross sections at loading points 9 Figure 6 Support details in tests 1, 2 and 3 9 Publication referred to Inside back coverBS5507-1:1977 ii BSI 10-1999 Foreword The need to establis

10、h accurately the structural properties of equipment has become more important, and in consequence, the need to have satisfactory test methods. These should relate as closely to practice as possible and be completely reproducible. This British Standard, prepared under the direction of the Builders Pl

11、ant and Equipment Standards Committee, is the first of a series of test methods for common types of falsework equipment. Floor centres are usually of lattice construction with each unit consisting of two or more sections telescoping one within another. There are many practical difficulties in assess

12、ing the strength and other related properties of these units by analytical approach alone and it has become customary for the users to rely on safe load tables and other information largely based on test results and published in the suppliers literature. At present in the UK there is no generally re

13、cognized method of conducting these tests or interpreting their results. It is hoped the tests described here will provide a common and verifiable basis for the determination of structural properties. Using appropriate safety factors, load/span tables can be prepared. These methods can also be used

14、as a design tool when developing a new or modified type of floor centre, as an aid in quality control in production and for assessing the degree of serviceability of used floor centres. Guidance on the application of test1to the last kind is given in Appendix A. Guidance on which tests to use in par

15、ticular circumstances is obtainable from Appendix B, which sets down the basis on which tests were formulated. Appendix C suggests how the test data may most usefully be interpreted for the user. At least two tests of each type should normally be undertaken. The material of which the samples tested

16、are made will sometimes have significantly better properties than the minimum required by its specification. Thus the test results from such samples will give optimistic results for the equipment. Consideration was given to adjusting the results based on the relationship of minimum strength expected

17、 and that of the critical part of the centre. However, owing to the difficulty of setting down a precise and reliable method for local testing and adjustment of the properties it was not possible to include this proposal. Successful use of this standard method will produce more meaningful data from

18、fewer tests. It is hoped users will record problems so that if necessary improvements can be made in due course. The test methods specified in this standard provide information for the great majority of requirements. Where other tests are needed the information given will be of direct use in formula

19、ting them. 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 of itself confer immunity from legal obligations. Summary of pages This document

20、 comprises a front cover, an inside front cover, pages i and ii, pages1 to 10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS5507-1:1977 BS

21、I 10-1999 1 1 Scope Four tests are specified for establishing the structural properties of floor centres in respect of bending strength, deflection, shear, strength at the overlap and the effect of propping from below. These can be used both for initial assessment, and to assess used equipment. Meta

22、llurgical examination is not considered. 2 Reference The title of the publication referred to in this standard is shown on the inside back cover. 3 Principles 3.1 Symbols and subscripts. The following are the meanings of the main symbols and subscripts used in this standard. Symbols Subscripts The m

23、eanings of other symbols used are given in the text. 3.2 Definition. For the purposes of this Part of BS5507the following definition applies. floor centre an adjustable metal beam of two ormore telescoping sections usually of lattice construction used to support soffit formwork. Its use is structura

24、l 3.3 Accuracy of readings and tolerances. testloads, deflections and spans should be measured within the following limits. a) 0.04P or 0.02P ultwhichever is the more restrictive for the test load P; b) 1mm for the central deflection m ; c) 0.2mm for the local deformation p ; d) 5 mm for the clear s

25、pan 1; e) 2 mm for the dimension locating the bearer tongue support b. 3.4 Sampling. Before setting up the tests, the tester shall identify the specimens by comparing them with drawings and other documents supplied by the organization requesting the test and note complete agreement on points of disc

26、repancy. The compliance shall be within specified or implied tolerance limits and include dimensions, weight, form and construction details. The purpose of this inspection is to ensure that the units tested are representative samples of the group and to allocate to them an appropriate identification

27、 reference. 3.5 Preparation of specimens. Units shall be tested with fixing components such as bolts, turnbuckles, pins and wedges in position and fully tightened up in accordance with instructions for use from the supplier so as to eliminate slackness at joints and thus achieving maximum camber. a

28、length of the horizontal part of the bearing tongue see Figure 6(a). b horizontal distance between the support face (at the root) of the bearing tongue and the centre of the end bearing see Figure 6(a). c clearance between a loading platform and the adjacent section (see Figure 3). d dimension of a

29、loading platform along the centre line of the unit (see Figure 1, Figure 2 and Figure 3). k clear distance between the ends of two non-adjacent sections in a three section unit (see Figure 4). l overall length of the floor centre excluding the horizontal parts of the bearing tongues see Figure 1, Fi

30、gure 2, Figure 3 and Figure 6(a). P test load applied through one loading platform or loading beam to two units (seeFigure 1, Figure 2, Figure 3 and Figure 5). the deflection of the points specified in various tests, calculated or observed as appropriate. m deflection of the top surface at the centr

31、e of the span in tests 1, 2 and 3 with reference to the ends. P the deformation remaining, in test 4, when the load is removed. max andmin refer to the maximum and minimum extension of the units. i initial reading. m at the centre. P permanent deformation. 1 to 4 refer to the tests of these numbers.

32、 ult the figure at failure.BS5507-1:1977 2 BSI 10-1999 4 Test arrangement and apparatus 4.1 General. Floor centres are generally used in assemblies of two (inner member and outer member) or three (two outers and one inner or two inners with the centre section an outer). These assemblies are usually

33、free standing, i.e. simply supported at each end, but sometimes an intermediate support is used. Where such supports are used it is usual for the screw or wedge connector adjacent to the prop to be loosened so that the spans are simply supported on the prop. If it is required to determine the ultima

34、te bending strength of a floor centre assembly it may be necessary to consider the position of an overlap between members as this can be the most critical section of the assembly when subjected to bending. It is also important to consider the shear capacity of assembled floor centres, both at the en

35、ds where the lug supports occur and at any other positions including where intermediate supports may be positioned. In all tests two floor centres shall be placed side by side450mm to750mm apart and parallel to each other. The load shall be applied to the centres distributed as uniformly as possible

36、, and transmitted via loading beams spanning transversely between floor centres. Packing pieces may be used to ensure that the pressure on the top of the floor centre is uniform, e.g. under the horizontal loading beams in cases where two floor centres have slightly varying profiles. Loading beams us

37、ed to transmit loads to the floor centres should be sufficiently stiff to prevent any torsion being induced in the floor centres. It is important that any load spreading equipment should not give additional stiffness or strength to the floor centres being tested. Failure of the floor centres can occ

38、ur in the vicinity of an overlapping joint; consequently, loading beams and any packing material should be kept clear of these areas. To produce a loading simulating a UDL a number of loading beams, at least 4, should be positioned at equal centres of not more than1m and such that the distance from

39、the supports to the nearest loading beam is half the distance between loading beams. 4.2 Details of supports. For tests 1, 2 and3the end details shall be generally in accordance with Figure 6(a) except that, if preferred, the20mm diameter roller may be replaced by a half-round ridge of20mm diameter

40、and either securely fixed to the underside of the packing or forming an integral part of it. The packing piece shall be secured to the bearer tongue by screws, clamps, clips or similar means in such a manner as not to affect the strength or stiffness of the end attachment. The dimension b shall be e

41、qual to a/2 when a 40mm, and to20mm in all other cases. The packing piece (with the 120 locating groove) and the20mm roller bar should be of steel. 4.3 Load points and unit configuration 4.3.1 Test 1. Bending moment and deflection. SeeFigure 1, Figure 5(a) and Figure 6. This test procedure produces

42、information on bending and deflection characteristics of floor centre assemblies spanning freely between end supports and where an overlapping joint does not occur near to the span centre. The maximum bending moment is therefore applied to a part of the structure other than at an overlap. The number

43、 of loading points may vary with the span so that the load distribution on the centres follows closely a uniformly loaded condition, e.g.Figure 1 shows a satisfactory arrangement for a span of5m using8point loads. Test 1 is suitable for both two and three member assemblies simply supported at the en

44、ds. Unless otherwise required test 1 shall be carried out on fully extended floor centres when 1 = 1 max . 4.3.2 Test 2. Interaction forces at lapped joint. SeeFigure 2, Figure 5(a) and Figure 6. The intention of this test is to subject the minimum overlap length of two members to bending. The proce

45、dure will provide information on bending and deflection characteristics of an appropriate combination of two members spanning freely between end supports. The overlap joint should be positioned as near to the centre of the span as is possible when the floor centre is fully extended. This arrangement

46、 is designed to test the bending strength of the minimum overlap length. Figure 2 shows a typical testing arrangement. The number of loading points may vary with the span with the intention of applying a maximum and constant bending moment in the vicinity of the lapped joint.BS5507-1:1977 BSI 10-199

47、9 3 4.3.3 Test 3. Shear and support forces. See Figure 3, Figure 5(a) and Figure 6. This test produces information on shear at floor centre ends and bearing tongue strengths. The floor centre under test will consist of two members as far as possible, provided that there is at least150mm between the

48、support under test and the end of the further member. Loads are to be applied close to the end under test and each type of end should be tested. Figure 3 shows a typical testing arrangement. 4.3.4 Test 4. Intermediate propping force. SeeFigure 4 and Figure 5(b). This test produces information about

49、propping a component and any deformation caused. For units with solid webs the load shall be placed at the centre line. In the case of lattice construction, it shall be placed under the node point nearest the centre line. Alternatively, it may be placed midway between the node points nearest the centre line. Exceptionally for this test, only a pair of single components is used. In this test the load P shall be capable of being completely released at any stage by removing the loading beam so as to permit measuring the local def