1、 Collection of SANS standards in electronic format (PDF) 1. Copyright This standard is available to staff members of companies that have subscribed to the complete collection of SANS standards in accordance with a formal copyright agreement. This document may reside on a CENTRAL FILE SERVER or INTRA
2、NET SYSTEM only. Unless specific permission has been granted, this document MAY NOT be sent or given to staff members from other companies or organizations. Doing so would constitute a VIOLATION of SABS copyright rules. 2. Indemnity The South African Bureau of Standards accepts no liability for any
3、damage whatsoever than may result from the use of this material or the information contain therein, irrespective of the cause and quantum thereof. ISBN 978-0-626-22847-7 SANS 10155:2009Edition 1.2Any reference to SABS 0155 is deemedto be a reference to this standard(Government Notice No. 1373 of 8 N
4、ovember 2002)SOUTH AFRICAN NATIONAL STANDARD Accuracy in buildings Published by SABS Standards Division 1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001Tel: +27 12 428 7911 Fax: +27 12 344 1568 www.sabs.co.za SABS SANS 10155:2009 Edition 1.2 Table of changes Change No. Date Scope Amdt 1 1
5、994 Amended to comply with present accepted practices in the building industry. Amdt 2 2009 Amended to change the designation of SABS standards to SANS standards, and to update referenced standards. Acknowledgement The SABS Standards Division wishes to acknowledge the valuable assistance derived fro
6、m publications of the British Standards Institution. Foreword This South African standard was approved by National Committee SABS TC 59, Construction standards, in accordance with procedures of the SABS Standards Division, in compliance with annex 3 of the WTO/TBT agreement. This document was publis
7、hed in September 2009. This document supersedes SABS 0155:1980 (edition 1). A vertical line in the margin shows where the text has been technically modified by amendment Nos 1 and 2. SANS 10155:2009 Edition 1.2 1 Contents Page Acknowledgement Foreword 1 Scope . 3 2 Definitions 3 3 Accuracy in buildi
8、ng . 8 3.1 General 8 3.1.1 Factors relating to permissible deviations 8 3.1.2 Grades of accuracy 8 3.2 Sources of dimensional inaccuracy 9 3.2.1 General . 9 3.2.2 Inherent inaccuracies . 9 3.2.3 Induced inaccuracies 9 3.3 Allowance for inaccuracies 10 3.3.1 Design stage . 10 3.3.2 Components manufac
9、tured off site 10 3.4 Tolerances and fit in the design of a building 11 3.4.1 Design stage . 11 3.4.2 Prefabricated components . 11 3.5 The use of grids 12 3.6 Setting out . 12 4 The control of accuracy 12 4.1 Sources of inaccuracy . 12 4.2 Control of accuracy in setting out 13 4.2.1 General . 13 4.
10、2.2 Measuring instruments . 13 4.2.3 Use of measuring instruments. 14 4.2.4 Setting-out methods . 17 4.3 Control of accuracy in the manufacturing process. 18 4.3.1 Manufacture off site 18 4.3.2 Manufacture on site 19 4.3.3 Manufacture of formwork 19 4.4 Control of accuracy in the erection process (i
11、ncluding in situ work) . 19 4.4.1 Erection of components 19 4.4.2 Erection of formwork 20 4.4.3 Limitation of displacement during concreting . 20 5 Permissible deviations (PD) . 20 5.1 General 20 5.2 Selection of grades of accuracy 20 5.3 Setting out . 21 5.4 Concrete 22 5.4.1 In situ concrete and e
12、rection of precast concrete 22 5.4.2 Permissible deviations 22 5.4.3 Lift-shafts 27 SANS 10155:2009 Edition 1.2 2 Contents (concluded) Page 5.5 Masonry work 28 5.5.1 General . 28 5.5.2 Workmanship 28 5.6 Structural steel 29 5.6.1 General . 29 5.7 Timber . 30 5.7.1 General . 30 5.7.2 Structural frame
13、s (other than roof trusses) 30 5.7.3 Timber components 31 5.7.4 Timber roof trusses 31 5.8 Floor and ceiling finishes . 33 5.8.1 General . 33 5.8.2 Prefabricated floor units . 33 5.9 Stairs . 33 Appendix A Applicable standards 35 SANS 10155:2009 Edition 1.2 3 Accuracy in buildings 1 Scope 1.1 This c
14、ode of practice covers the method of measurement and accuracy of dimensions required for the setting out of structures and for completed building work. Permissible deviations are prescribed for the positioning and dimensions of the various elements. NOTE The standards referred to in the code are lis
15、ted in appendix A. 2 Definitions 2.1 For the purposes of this code the following definitions shall apply: bow curvature of the length or width of the component expressed as the maximum deviation from a straight line connecting the extremities component a building product formed as a distinct unit, h
16、aving specified sizes in three dimensions creep slow inelastic deformation (or movement) due to stress or other factors deviation the difference between a size or position (actual, limiting, etc.) and a specified size or position element a functional part of a building, constructed from building mat
17、erials, or building components, or both kicker a starter member used for locating construction which follows (see figures 1, 2, and 3) master datum MD the datum level from which all levels on site are derived NOTE The level of the master datum is determined usually by reference to the nearest conven
18、ient Trigonometrical Survey Datum, or Local Authority Datum derived from it. Permissible deviation PD specified limit(s) of deviation SANS 10155:2009 Edition 1.2 4 starter bar reinforcement left projecting from concrete to provide continuity of reinforcement (see figure 1) tolerance the difference b
19、etween the permissible limits of size or between the permissible limits of position Transferred datum TD subsidiary datum level derived from the master datum twist spiral distortion of a surface of a component measured as the deviation of one corner from the plane containing the other three corners
20、work size the size together with its permissible deviations, as specified for the manufacture of a component the actual size of which should lie within these deviations, under reference conditions SANS 10155:2009 Edition 1.2 5 Section through floor/column junction showing the kicker NOTE Floor reinf
21、orcement and column links have been omitted for clarity. Figure 1 Typical column kicker SANS 10155:2009 Edition 1.2 6 Sectional evaluation of floor/wall junctionSection A - A NOTE1 Floorreinforcement has been omitted for clarity. NOTE2 Splice bars are required only wherefloor and wallreinforcement a
22、re of steel fabric. With rod reinforcement, wallbars should extend alap length above the kicker intothe wall above. Figure 2 Typical in situwall kicker SANS 10155:2009 Edition 1.2 7 Sectional evaluation of floor/wall junctionSection A - A NOTE1 Floorreinforcement has been omitted for clarity. NOTE2
23、Splice bars are required only wherefloor and wall reinforcement are of steel fabric. With road reinforcement, wall bars shouldextenda lap length above the kicker into the wallabove. Figure 3 Typical precast wall kicker SANS 10155:2009 Edition 1.2 8 3 Accuracy in building 3.1 General As absolute accu
24、racy exists only in theory, tolerable degrees of inaccuracy have to be accepted in practice. The code is concerned with degrees of inaccuracy that are acceptable for all practical purposes. The tolerances specified should be as large as possible without rendering the finished building, or any part o
25、f it, unacceptable for the purpose for which it is intended. If the permissible deviations specified are smaller than can be achieved by usual techniques, special action may be required, such as a) increased supervision and control; b) special training of workmen; c) revised methods of manufacture a
26、nd construction. These measures may increase the cost of individual processes or even of the whole project. It is for the designer to judge whether the increased cost is justified by the results obtained or whether it can be offset in part by savings in other directions. It is important that these p
27、oints should be borne in mind and detail drawings should provide for permissible deviations appropriate to the building being designed. 3.1.1 Factors relating to permissible deviations In determining permissible deviations, take into account the following considerations: a) Aesthetic. The deviation
28、that is permissible depends on the function of the building and the standard of finish appropriate to it. b) Structural. The design of structural components and their erection should avoid eccentricities of loading or inadequate areas for load bearing that may result in design stresses being exceede
29、d. c) Legal. The finished building should be located correctly in relation to the boundaries of the site. Correct location may be affected by the accuracy of the survey, or the setting out, or both. d) Practical. To avoid excessive production costs or the cost of cutting to fit or of other such adju
30、stments, the tolerances specified should be consistent with the expected methods of manufacture and construction and should be related to the combined costs of both. 3.1.2 Grades of accuracy Where different grades of accuracy are given in the code, decide on the grade required for each element or co
31、mponent. For example, while grade II may be suitable for the majority of the concrete work in a building, some work may have to conform to grade I (see 5.2). SANS 10155:2009 Edition 1.2 9 3.2 Sources of dimensional inaccuracy 3.2.1 General There are two kinds of dimensional inaccuracy: a) Inherent (
32、i.e. inaccuracies due to the nature of the materials involved); and b) induced (i.e. inaccuracies brought about by the work done). 3.2.2 Inherent inaccuracies Causes of inherent inaccuracies include the following: a) movement of foundations (caused by, for example, movement of the substrata); b) def
33、lection under load (excluding designed cambers (see 5.4.1); and c) changes in dimensions caused by variations in temperature or moisture content or other similar causes. The inaccuracies to be expected in respect of (a), (b), and (c) above are dependent upon the materials concerned and upon their en
34、vironment in the structure. Ensure that allowance is made for these effects as the resulting movement could be considerable and may not take place until long after construction has been completed. 3.2.3 Induced inaccuracies Measuring instruments are only relatively accurate and at best can be read o
35、nly to the smallest division of graduation. The interpretation of instrument readings varies between individuals, thereby adding to instrument inaccuracy. Dimensions, shape, and location of building elements are established by measurement and these will therefore be inaccurate, at least to the exten
36、t of error in measurement. Other dimensional deviations will arise from the manufacturing and the erection processes and may be larger than measurement deviations. The sources of induced inaccuracies are as follows: a) In setting out. Inaccuracies that may arise in the following: 1) the survey; 2) t
37、he survey drawing; 3) the positioning of survey stations on the site; 4) the positioning of site grid stations that gives rise to errors of distance between site grid lines; 5) the positioning of site grid stations that gives rise to errors of angular relationship (non-parallelism) between site grid
38、 lines; 6) the establishing of the level of the master datum (MD) from the Trigonometrical Survey Datum; 7) the establishing of the levels of transferred datums (TD) from the MD; SANS 10155:2009 Edition 1.2 10 8) the establishing of the desired level of building elements with reference to an adjacen
39、t TD; 9) the setting out of the lines of the site and structural grids or secondary reference system that gives rise to errors of distance between grid lines; 10) the setting out of the lines of the site and structural grids or secondary reference system that gives rise to errors of angular relation
40、ship (non-parallelism) between grid lines; and 11) the establishing of the desired position of a building element with reference to adjacent grid lines. NOTE Items (1) - (7) may not affect the fit of elements within a building but any one could affect the position of a whole building (i.e. in relati
41、on to the Trigonometrical Survey Datum, adjacent buildings, or other existing features). b) In manufacture. Inaccuracies that may arise in the determination of the following: 1) Size: Dimensions in three directions (e.g. length, width, height); 2) Shape or form: Squareness, bow, twist, and regularit
42、y of surface or line. c) In assembly and erection. Inaccuracies in assembly and erection (errors in location) include the following: 1) Position in plan; 2) verticality; and 3) level. 3.3 Allowance for inaccuracies 3.3.1 Design Stage Bear in mind during the design stage that inherent and induced ina
43、ccuracies may exist or be caused during construction and make allowance for these by specifying permissible deviations. Some causes of the induced inaccuracies that may be expected under normal conditions are given in section 4. The space for a component, the size of the component, the design of the
44、 joints between the component and adjacent components, and the appropriate manufacturing, setting-out, and assembly tolerances are all interrelated. To avoid problems of fit, ensure that the values chosen for each of these are compatible one with the other, the combined effect of the tolerances bein
45、g determined as in SANS 993. 3.3.2 Components manufactured off site Obtain values of permissible deviations from the appropriate South African standard(s) or, where no South African standard exists, from any standard(s) recommended by the South African Bureau of Standards. The permissible deviation
46、values for work on site are given in section 5. Individual attributes of components, e.g. bow, twist, may not occur in isolation and therefore cannot always be checked individually. In such cases, make check measurements to determine the combined effects. SANS 10155:2009 Edition 1.2 11 3.4 Tolerance
47、s and fit in the design of a building 3.4.1 Design stage For each factor given in column 1 of table 1, factors are set out in column 2, values of which may be known or assumed. Determine in each case, by calculation or that is not known or can not be assumed. Table 1 Design factors 1 2 Factors to be
48、 determined Known or assumed factors Setting-out and assembly tolerances Space available for component Component size, and manufacturing tolerance Joint design, including tolerances Joint design, including tolerances Space available for component Component size, and manufacturing tolerance Setting-o
49、ut and assembly tolerances for the project Size of component, and manufacturing tolerances Space available for component Joint design, including tolerances Setting-out and assembly tolerances Dimensions of space to accommodate component Component size, and manufacturing tolerance Joint design, including tolerances Setting out and assembly tolerances for the project 3.4.2 Prefabricated components a) Where prefabricated components are built in as work proceeds, problems of fit should not arise. However, where prefabricated components are to be fitted into spaces left for them,
