SANS 10120-5 LE-1982 Code of practice for use with standardized specifications for civil engineering construction and contract documents Part 5 Contract administration Section LE S.pdf

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. SAUS 0120 : Part 5 section LE-1982 Stormwater drainage PART 5 : CONTRACT ADMINISTRATION SECTION LE CONTENTS Clause 1 . 1.1 2 . 2.1 2.2 3 . 3.1 3.1.1 3.1.

4、2 3.1.3 3.1.4 3.1.5 3.1.6 3.1.7 3.1.8 3.2 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 4 . Page Number START OF CONSTRUCTION 1 General 1 . IMMEDIATELY AFTER THE IIANDING OVER OF THE SITE 1 Phasing of Work 1 Skewed Ends 1 . DURING CONSTRUCTION 1 Methods of Construction 1 General 1 Materials . 1 . Stoppihg of mechan

5、ical excavation above final invert 1 Excavation to below bottom of pipes 1 Prevention of unstable conditions 1 Dealing with water during laying and backfilling . 1 Backfilling of trenches 1 Road surfaces 1 . Administration 2 Using unreinforced in lieu of reinforced concrete pipes 2 . Program for des

6、ign details 2 . esting of stormwater drains 2 Measurement and brickwork 2 Corrugated metal culverts 2 . QUALITY CONTROL AND OTIIER CONSIDERATIONS 2 First Revision November 1982 This section of the code supersedes SABS 0120 : Part 5 : Section LE-1980 Approved by the COUNCIL OF TI1E SOUTli AFRICAN BUR

7、EAU OF STANDARDS SABS 0120 : Part 5 Section LE-1982 btormwater drainage SABS 1200 LE : STOHMWATEH DHAINALE NOTE: The clause number(s) given at the beginning or after the heading of a clause is/are, unless otherwise stated, the numberls) of the relevant clause(s) oL LABS 1200 LE. START OF CONSTRUCTIO

8、N GENERAL. For the purposes of this part of the code contract administration starts with instructions to the contractor to commence work as set out in Subclause 4.1 of Section 0. IMMEDIATELY AFTER TIIE IlAIJDING OVER OF THE SITE PIIASING OF WORK. The program that is agreed for the sequence of constr

9、uction should be suh that both excavation and construction are free-draining at all tlmes. Stormwater drains are frequently constructed in trenches excavated below ground level, or through completed embankments, or in and through roads. Construction in tlre open is preferable for cast-in-situ culver

10、ts and tlre larger portal or rectangular culverts. The practicability of excavating through tinlshed embankments depends upon the size of the culvert and the embankment arid on local and climatic conditions that should be known to the engineer. lie should make known such information while the progra

11、m is bemg prepared. SWWED ENDS (Subclause 8.2.4(b). Immediately after handing over the site, the engineer should provide the contractor with a schedule of skewed ends, if any. DURING CONSTRUCTION METHODS OF CONSTRUCTION General. Pipes of the tlnest quality and complying with a standard specification

12、 can be ruined by improper handling and by improper bedding and backfilling. In calculating the strength of a pipeline, certain dssumptlons are made 111 the design criteria regarding trench width, type of bedding, and backfilling, and 1t is the purpose of 3.1.2 - 3.1.8 below to describe how optimum

13、conditions can be achieved in practice. Materials. Each plpe used should corrply with the applicable specification, should be protected during transportation and handling from damage caused by impact, dropping, etc., and should be inspected for defects immediately before laying. Faulty pipes or pipe

14、s that have suffered damage sufficient to affect their serviceability should not bc used in the work. Stopping-pf Mechanical Excavation-Above Final Invert. Where a pipe is to be bedded directly on a natural earth bed, i.e. on Class D bedding, the mechanical excavatiou of trenches should be stopped s

15、ufficiently above the final elevation of the bottom of the pipe to enable the pipe barrel to be laid on a firm undisturbed earth Led. If overdigging occurs, all loosened earth should be removed and the trench bottom brought back to grade with well-compacted material. Excavation to Relow Uott_om of P

16、ipes. In rock or waterbearing earth or where a concrete or granular bed is to be provided, excavation should be carried to the depth below the pipe bottom required for the specified class and thickness of beddiny to be used. Prevention of Unstable Conditions. Particular care should be taken with ear

17、th which, though firm when trenched, may be rendered unstable by rain or by seepage from drainage lines or leaking water mains. Dealing-with Water During Laying and Backfilling Urrtil the pipeline has been laid and backfilled, t 1s essential that the bottom of the trench should be kept sufficiently

18、free from water to enable the bedding to be prepared and the pipelme laid. In the cases of Class A, Class B, and Class C bedding this means the trench must be kept very dry. The following precautions should be taken for dealing with water: a) Surface water shuuld be so controlled by the deposition o

19、f excavated material and the construction of dramage channels as to prevent such water or stormwater from entering the trench. b) When ground water is present, an adequate side channel should be made in the trench bottom at one side of the trench, to drain such water away. Provision should be made t

20、o drain the water away from this channel at a low punt or to remove it by pumping. Care should be taken to prevent water from entering backfilled trcnclres. Backfilling of Trenches (Subclause 5.4). Except when Class A bedding is used, trenches should be backflled as soon as possible after the pipe h

21、as been laid. It is of ingortance that backfilliny should be properly compacted in layers of suitable thickness, depending on local conditions. Filling around and on top of the pipe should be done accurdiriy to the requirements given for the class of bedding used. Compactior should be carried out un

22、iformly so as not to displace the pipeline laterally or in a vertical direction. Where machines are used for backfilling and compaction, care must be taken not to subject the pipeline to loads greater tlrau those for which it has been designed. Where excess material does not have to be rcnoved, it s

23、hould be spread uniformly over the top of the trench fill, a,d provision should be made for cross-drainage. 3.1.8 Road Surfaces. Hardened road surfaces should be reinstated promptly. SN3S 0120 : Part 5 Section LE-1982 Stormwater drainage 3.2 ADMINISTRATION 3.2.1 Using Unreinforced in lieu nf Reinfor

24、ced Concrete Pipes. Where a project specification clause requires all stormwater pipes to be of reinforced concrete, the alternative of usin3 nreinforced pipes may be considered by the engineer provided that they contply with SABS 67711, the applicable proof load being increased by a factor of 1,3.

25、(See Subclause 3.2.l(a) of Section LE of Part 2 of the code.) 3.2.2 Program for Design Details. The engineer should provide design details in a sequence such that all trenching and plpelaylng is commenced from the lower end of each culvert or stormwater drain so as to permit laying to proceed upgrad

26、e and the outlet end to be free-draining at all times. 3.2.3 Testing of Stormwater Drains. Except where the engineer has ordered a water test, a stormater drain should only be inspected by the engineer to ensure that it has been laid in accordance with the specification. 3.2.4 Measurement and Brickw

27、ork (Subclause 8.2.8 or 8.2.9). Attention is drawn to the fact that brickwork is measured not externally or internally but on the centre line. This is the standard nethad of measurement adopted by quantity surveyors and is the logical and correct method to adopt for civil engineering work. 3.2.5 Cor

28、rugated Metal Culverts. The contractor should pay attention to the manufacturers recomendations. He should check these carefully against the specification and design application and he should check especially the quality of material to be used for backfill, with particular reference to any warranty

29、that the contractor (and hewe the manufacturer) may be required to give to the employer. NOTE a) In one case involving a metal culvert it was found that the corrugations had been fomed by bending over rollers in a local factory that was not equipped to comply with the parent companys (nor the engine

30、ers) specification with the result that adjoining sections did not mate properly. b) In the case of a very large twin metal culvert constructed in 1972, the supplier insisted that, for the warranty to be valid, subbase material was to be used as backfill. The cost to the client of the finished struc

31、ture was increased by about R150 000 because it was necessary to import sukbase material instead of using the backfill available on site. 4. QUALITY CONTROL AND OTIIER CONSIDERATIONS 4.1 Apply the relevant recommendations of SABS 0157) to the construction of stormwater drairage. 1) Concrete non-pressure pipes. 2) Quality management systems.