SANS 10120-3 F-1983 Code of practice for use with standardized specifications for civil engineering construction and contract documents Part 3 Guidance for design Section F Piling《.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. Clause 1 . 1.1 1.1.1 1.1.2 1.1.3 1.1.4 1.2 1.2.1 1.3 1.3.1 1.3.2 1.3.3 1.3.4 1.3.5 1.3.6 1.3.7 1.3.8 1.3.9 2 . 2.1 SABS 0120 : Part 3 Section F-1983 Pi l

4、ing PAN 3 : i;UIL)ANCE FOR TlCSIGN SECTION F CONTENTS Page Number IRE-TENDER CONSlDERATIONS . Investigations . Expenditure on i.nvestigations Tests on substra1.a . setting out resu1t.s oi tests on substrata . Special test piles (trial test piles) Administration Guarantee . . Document.ation Condition

5、s of tender Conditions of contract . Selection of speciIications . Project and particular specifications Scheduling . Detail sheets Piling conditions and guarantee considerations . Measurement and payment in respect of alternative piling . Testing and acceptance criteria . DESIGN REQUlREMENTS Design

6、 Code . . Loads Nominal load and test load Safe or allowable load Uncertain Obstructions . Permanent Steel Casings Settlement Self Compacting Concrete . Reinforcing Steel Aggressive and Artesian Water Conditions Prestressed. Timber. and Steel Piles APPLICABILITY OF OTHER CODES Safety Design Other Re

7、ferences . TEST PROCEDURES . General QUALITY CONTROL AND OTHER CONSIDERATIONS General . Disputes August 1983 Approved by the COUNCII . OF THE SOUTH AFRICAN BUREAU OF STANDARDS i SABS 1200 F : PILING SABS 0120 : Part 3 Section F-1983 Filing NOTE: The clause number(s) given at the beginning or after t

8、he heading of a clause is/are, unless otherwise stated, the numher(s) of the relevant clause(s) of SABS 1200 F. PRE-TENDER CONSIDERATIONS INVESTIGATlONS Expenditure on Investigations. Expenditure, before the tender is prepared, on thorough investigations into the nature of the strata through which a

9、nd in which piles are to be installed is a sound investment because, if both the designer and the contractor know that the information supplied is correct, they should be able to produce the most economic design which should lead to the lowest tender prices and result in the lowest cost to the emplo

10、yer. Tests on Substrata (Subclause 5.1.2). Ensure that the results of tests on substrata required to be given in the project specification are as comprehensive as it is practicable to make them, and that all available data on known obstacles are disclosed. (See also 2.8 below and Subclause l.l(c) of

11、 Section F of Part 2 and Subclause 3.2.2 of Section F of Part 5 of the code.) Setting Out Results of Tests on Substrata. Unless the data are so brief that they can be dealt with in Clause PS3 of the project specification or, if such data and the positions at which tests were carried out are not show

12、n on the drawings, ensure that the results 01 subsoil investigations that were carried out (see 1.3.l(a) below) are included in an annexure to the project specification. (See 1.3.5.1 below and also Subclause 4.1 of Section 0 of Part 2 and Subclause l.l(c) of Section F of Part 2 of the code.) Spxial

13、Test Piles (Trial Test Piles). Where, in order to obtain or confirm data, a special test pile is installed either before tenders are invited or before the main piling installation is commenced, determine the nominal load per pile in the manner described in 2.2.1 below. ADMINISTRATION Guarantee (Subc

14、lauses 7.8.1 and 7.8.2). Ensure that the employer understands the implications of the guarantee and liability clauses and determine whether he is agreeable to their forming part of the contract. (See also 1.3.7 below.) DOCUMENTATION Conditions of Tender. When preparing the conditions of tender a) dr

15、aw attention to Clause PS 3 of the project specification, to the annexure to the project specification, if any, and to the drawings on which the results of a subsoil investigation carried out on the site of the works are given, and state that the positions at which tests were carried out are shown o

16、n the drawings; b) state that the tenderer is to base his tender and any alternative design and priced schedule on the information referred to in (a) above; C) where applicable, add that additional site investigation by the tenderer during the tender period will be permitted should he wish to obtain

17、 additional information pertinent to his foundation design and that the cost of such additional investigation will be for the tenderers account, the information obtained being for his use exclusively; and d) where an alternative tender, design, type of pile, or layout is required or will be consider

18、ed, set out the requirements and draw attention to the requirement that the original schedule must be priced. (See Subclauses 5.1.3 and 0.1.2 of SABS 1200 F, and Subclause Z.l(h) of Section F of Part 2 of the code.) Conditions of Contract. Where the GCC) are not applicable to the contract, ensure th

19、at the applicable conditions of contract include a clause such as the following: to be materially different from those shown on the drawinas or aiven in the ;ender documents, the Contractor shkl notify the Engineer in writing of any intention to claim for additional payment on the grounds of additio

20、nal costs arising from the different subsoil conditions. Such notification shall be delivered to the Engineer within 14 d after the change in conditions has been so proved. (See also Subclause l.lfc) of Section F of Part 2, and Subclause 3.2.2.1(b) of Section F of Part 5 of the code. ) Selection of

21、Specifications General. SABS 1200 AH may be a more suitable general specification than either SABS 1200 A or SABS 1200 AA in the case of a “piling only“ contract. Earthworks. Unless the piling work forms a relatively minor part of a major civil engineering contract, neither SABS 1200 D nor SADS 1200

22、 DA need be included in the contract. Such clauses relating to earthworks as are required for the purposes of piling should be selected from SABS 1200 D and included in the project specification. 1) General conditions of contract for use in connection with works of civil engineering construction, pr

23、epared under the auspices of the SAICE, SAACE, and SAFCEC and recommended by these bodies for general use, and also endorsed for general use by the Civil Engineering Advisory Council. (See also Clause C-l(d1 of Annexure C of Part 1 of the code.) SABS 0120 : Part 3 Section F-1983 Filing Projec:t and

24、Particular Specifications a) Prtstressed piles. Where prestressed pile:; are required, compile a particular specification or include SARS 1200 F in the contract. and set out. suitable requirements in the project specification. b) Steel piles. Where steel piles arc required, set out, in a suitable pr

25、oject specification clause, the applicable requirements for steel piles, to replace those given in Subclause 5.6 of SAILS 1200 F for precast concrete piles. C) cnber piles. Where timber piles are required, compile a particular specification or include SABS 1200 I- in the contract. and set. out in th

26、e pro:ject specification requirements covering the types of timbox that will be acceptable, protection against infestation or attacks by marine borers, and any other requirements that are necessary to cover the construction of timber piles and their heads and caps. Scheduling Obstructions (Subclduse

27、s 3.4 and 8.2.5). Where pre-tender investigations have disclosed the presence of obstructions such as coarse gravel, boulders, etc., schedule them in accordance with the classification given in Subclause 3.4 of SABS 1200 F or designate them if they are foreign bodies such as foundations, old tree tr

28、unks, tinher, rails, rubber, etc. (See also Subclause 3.1.2 of Section F of Part 5 of the code. ) Additional foundation informati. (Subclauses 5.1.7 and 8.2.23). Where it is expected that additional - foundation information will be required durinq the contract, schedule suitable provisional items an

29、d state a provisional sum to cover the cost of obtaining the additional information. Detail Sheets (Subclauses 5.1.2 and 5.R). In order to establish details of the method, plant, and equipment the contractor proposes to use to achieve his intended rate of installation, compile a suitable detail shee

30、t, or sheets, based on that given LII Annexure A to Section F of Part 7 of the code, and include it/them in the tender document. Inclilslon of such sheets in the tender document simplifies the administration of a contract and the settlement of possible disputes wlwn obstructions are encountered or d

31、elays occur. (See also Subclauses 2.1 and 4.2 of Section F of Part 5 uf the code.) Piling Conditions and Guarantee Consideration!; (Subclauses 5.1.2, 5.1.7, and 7.8). The question whether or not a quarantee for piled foundations js oi any use should receive careful consideration for the following re

32、asons: a) The existence oi a guarantee may create a conflict as to the correct founding depths. If the engineer wants to found at shallow depth, the contractor may lnslst on going deeper to ensure that no tallure occurs that will render hm liable in terms at the quarantee. Conversely, if the contrac

33、tor experiences difficulties in the initial stages or sinking piles to the depth shown on the drawings (i.e. the depth on which he has priced the schedule) ancl 1s prep.nred to guarantee his work at some shallower depth, the engineer may he reluctant to accept the shallower depth of founding. b) Com

34、mon law may provide better protecLion for the employer (see also 5.2 below). When the tender documents are being drawn up, consider whether the amount stated as the limit of the contrmtors liability in Subclause 7.8 of SABS 1200 k is realistic. Measurement and Payment In Respect of AI t esna Live Pi

35、1 ing (SubcLuses 5.1.3 and 8.1.2) Comments and recommendations of the geotechnical divlsion of the SA Federation of Civil Engineering Contractors (SAFZ. The followirg are comments and recommendations of the SAFCEC with regard to measurements and paymrnt for piles constructed to an alternative design

36、 a) A requirement to the effect that the contractor must tender a lump sum price per pile 1s dcceptable to the SAFChC if the correctness of the soils information is guaranteed by the employer and if a clause coverlng unforeseen condition& (e.g. Clause 12 of the GCC) 1s operative. b) The basis of me

37、asurement In which a formula that lncorpoxates NI, XI, NZ, and X2 as symbols to relate the fmal payment to the numbers and depths oE piles and to other plling items requlred for the tendered and final installations, AS considered to be rather too involved for what t achieves. Where the said formula

38、1s used, the following should apply: 1) If the number of plles has been increased at the request of the engineer and not as a result of any deficiency in the alternative design, then N1 = N2 in the calculation of X. 2) If the final depth X? 1s less than the tendered depth X1, the contractor should g

39、aln proportionately X 2 to the ratio -. X1 C) Compliance wlth the SAFCEC recommendations and a compromise on the use of the formula referred to in (h) above are achieved by measuring each piling item up to the maximum depth indicated by the tenderer at the time of tender (beyond which depth no payme

40、nt is made) and taking into account the correctness of the soils information. NOTE: The recommendations of the SAFCEC are riot in conflict with the requirements of Subclauses 5.1.3, 8.1, and 8.2 of SABS 1200 F and the typical schedule qiven in Section F of Part 4 of the code. Tenders may therefore b

41、e analysed and compared Ln the manner given In (c) above. Application of Subclause 8.1.2 of S&RS 1200 F. The equity of Subclause 8.1.2 of SAUS 1200 F is dependent on accurate data as to the substrata being provided in the tender documents. The data set out In project specification Clause PS 3 (see C

42、lause 4 of Section 0 of Part 2 of the code) together with data glven on the drawings and in any annexures to the project specification, therefore form an important part of a contract to which the terms of Subclause 8.1.2 of SABS 1200 P are applicable. The incorporation, by the engineer, of a disclai

43、mer in Clause PS 3 is unlikely to be of any assistance in the event of a dispute. Should the substrata revealed durinq the execution of the work or during investigations or tests in terms of Subclause 5.1.7 of SABS 1200 F, be so different from these described in Clause PS 3 as to affect adversely th

44、e cost of constructing the piled foundations, a dispute is bound to arise. It would be difficult for the engineer to convince any arbitrator or any court that the contractor should have interpreted the data given in Clause PS 3 differently from the way in which the engineer interpreted them in arriv

45、ing at the design on which he called for tenders. 1) See p.1. SABS 0120 : Part 3 Section F-l983 Piling Testing and Acceptance Criteria (See 2.2 and 2.5 below and Suhclause 3.2.4.1 of Section F of Part 2 of the code. DESIGN REQUIREMENTS DESIGN CODE. Design the piling in accordance with the relcvant r

46、ecornendations of CP 2004) and the information and recommendations given in 2.2-2.8 below. LOADS Nominal Load and Test Load. Before inviting tenders, determine from an analysis of the critical load combination to be carried by a pile or a group or a system of piles a) the critical load (i.e. the wor

47、st combination of load cases: bending moments, live loads, dead loads, etc. ) b) the nominal load per pile (or target load per pile) for construction pur-poses. (tinder normal circum- stances this load will be stated as a round number of kilonewtons (or tons), the figure being given to the nearest 1

48、00 kN (or l0 t) above the highest actual load to be carried by a pile in any particular group of piles.) Under normal circumstances the test load for the purposes of Clause 7 of SABS 1200 F will be 1,5 times the nominal load. Safe or.Al10wable Los. The safe or allowable load is that determined by te

49、st after installation. It is the load that may safely be applied to a pile after taking into account the ultimate bearing capacity (i.e. the load at which the resistance of the soil becomes fully mobilized), negative friction, the pile spacing, the overall hearing capacity of the ground below the pile, and the allowable settlement. For commcnt on curves derived frctm the results of tests carried out in terms of Clause 7 of SABS 1200 F, see Subclause 3.1.10 of Section F of Part 5 of the code. UNCERTAIN OBSTRUCTIONS. Where the incidence of obstructions on a site is likely to be hig