SANS 10120-2 DM-1981 Code of practice for use with standardized specifications for civil engineering construction and contract documents Part 2 Project specification Section DM Ear.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 SABS 0120 : Part 2 Sectlon DM-1981 Earthworks (roads. subgrade) PART 2 : PROJECr SPEClFlCATlON . PORTlON 2 CONTENTS Page Number ESSENTLAL PROJECP

4、SPEClFICATlON CLAUSES . 1 ESSEmIAI. DATA 1 AnRITIONAL CLAUSES 1 General . l . Normal ProJects 1 Compactton specified by number of passes or by percentage of proof density 1 Amended requirements for materials 3 Crushing and screening 3 Constructton of high Eills 4 Unstable ground conditions . 4 Compa

5、ctton . 5 Boulders proJecting above finished slopes . 5 Slope of fills 5 AccommodaLion oE traffic 5 Prestige Projects 1 6 . Subeconomic ProJects . 6 . Labour-Based Projects 6 SABS 0120 : Part 2 Section DM-1981 Earthworks (roads, subgrade) SABS 1200 DM : MRTHWOKKS (ROADS, SUBGRADE) NOTE a) Number the

6、 PSDM clauses in Portion 2 of the proiect specification in the sequence in which the clauses to which they relate appear in SARS 1200 DM. b) The clause number(sf given at the beginning or after the heading oE a clause is/are, unless other- wise stated, the number(s) of the relevant clausc(s) of SABS

7、 1200 DM. ESSENTIAL PROJECT SPECIFICATION CLAUSES Set out suitabIe clauses in Portion 2 of the project specification to provide essential information, as f ol lows : a) (Subclauses 2.1 and 5.2.7) Where SABS 1200 ME does not form part of the contract document. set out the requirements for stabilizati

8、on, if any. b) (Subclause 5.2.2.3(c) Where applicahle, state areas required to be topsviled. C) (Subclarrses 5.2.4.3(d) and (f) Set out the requirements for preparation for grassing and for grassing. if any. ESSENTIAL DATA The availability of certain essential data may affect the prices tendered. Ex

9、cept where such data have been given in the schedule or on the tender drawings, set out fiuitable clauses covering items such ss the following in Portion 2 of the project specification: a) Give the thickness of the selected layer(s). b) (Subclause 5.2.2.7(b), and Subclause 5.2.5.1(c) of SABS 1200 D

10、or 5.2.6.1(c) of SABS 1200 DA, as applicable) If possible, designate disposal sites if the expected volumes of cut exceed those of fill. c) (Subclause 5.2.2.3(d). and Subclalse 5.2.5.1(c) of SABS 1200 D or 5.2.6.1(c) of SABS 1200 DA, as applicahle) If possible, designate borrow pit sites if the expe

11、cted volumes oE fill exceed those of cut. d) (Subclause 5.2.4.3(e) Give the thickness of the finishing layer of topsoil if it is to be other than the thickness specified. e) (Subclause 5.1.2) If bypasses are necessary for temporary accommodation of traffic,give details. E) (Subclauses 3.2.4 and 5.2.

12、6) State whether a gravel surface is required and, if so, state its thickness. g) (Subclause 6.2) Where Degree of Accuracy Z or LLI is required for any operation for which such a PD is not specified, give the requirements. ADDITIONAL CLAUSES GENERAL. Where it is necessary to amplify or otherwise to

13、vary the terms of SABS I200 DM to render them suitahle for use in proJects to be carried out in particular locations or under particular circumstances, include suitable PSIIM clauses in Portion 2 of the proJect specification to deal with such matters in addition to those covered by Clauses 1 and 2.

14、NORMAL PROJECTS NOTE: To meet requirements imposed by various norms of economic development, projects are classified as normal, prestige. subeconomic, and labour-based projects (see Section O of Part 3 of the code). Compaction Specified by Number of Passes or by Perstage of Przf Density (Subclauses

15、5.2.3.3 and 5.2.4.2). Where the engineer is prepared to specify compactfon by means of a stated number of passes or by a percentage OF proof density instead of by stated densit.ies, consider the inclusion of clauses such as the following (see also Subclause 1.1.2 of Section DM of Part 3 and Subclaus

16、e 3.2.7 of Section DM of Part 5 of the code): PSDM 1. COMPACTION BY NUMBER OF PASSES AND PERCENTAGE OF:.PKOOF DENSITY PSDM 1.1 Plant for treatment below select-ed layer PSDM 1.1.1 Pneumatic-tyred roller. A pneumatic-tyred roller shall consist of pneumatic-tyred wheels mounted on a rigid Frame with a

17、 loading platfonn or body suitable for ballast loading to produce a load of at least 70 kN on each wheel and arranged in a manner that allows all wheels to bear equally while operating on uneven surfaces. The total load on any axle line shall not exceed 300 kN. Tyres shall be uniformly inflated unde

18、r operating conditions to a pressure within the range 500-800 kPa. PSDM 1.1.2 Vibratory roller. A vibratory roller shall be capable of exerting a combined static and dynamic load that is sufftcient to produce a compaction effort compatible with that of the other specified compaction equipment. PSDM

19、1.1.3 Grid roller. A grid roller shall have a mass of at least 13 t when ballasted, and shall be operated at this mass. May 1981 Approved by the COUNCIL OF THE SOUTH AFRICAN RUREAIJ OF STANDARDS SARS 0120 : Part 2 Section DM-1981 Earthworks (roads, subgrade) PSDM 1.1.4 Impact roller. An impact rolle

20、r shall be a single mtLtiEaced roller having a maximrm of five flat or nearly E lat faces and a mass of over 8 L. The roller shall be of the Free fall type. and the roller and towing mechanism shali be so designed Lhat all the energy applied in lifting the roller to the position in which it is suppo

21、rted on an edge between consecutive faces, is dissipated on impact when the roller drops again. PSDM 1.2 Preparation and compaction PSDM 1.2.1 Below selected Payer. Each portion of the road-bed below the selected layer which, by virtue oE its inadequate natural density, is shown on the drawings or s

22、pecified or directed to be compacted, shall be prepared by shaping where necessary,and each such portion shali be compacted by means of at least six complete passes (or such other number of passes as is ordered) by an approved combination of two or more of the rollers specified in PSDM 1.1. PSDM 1.2

23、.2 Within the selected layer. Any portion of the road-bed falling within the selected horizon and classified as suitable for use in place, save that it fails to comply with the requirements Eor density, shall he scariEied, watered, and compacted to a minimum of 98 X of the proof density, measured in

24、 the top 150 mm of the layer in the case of gravels and between 100 mm and 250 mm below the surface in the case of non-plastic sand. PSDM 1.2.3 *rmination of proof density. In order to determine the proof density the Contractor shall construct a trial section from material that is representative of

25、the material under test. The material shall be placed as specified in 5.2.4.2 of SABS 1200 DM and compacted by means of a combination of items of compaction equipment that gives the most efficient performance for the material in question, applied in twelve passes per 150 mm OF completed layer thickn

26、ess over every section of the area to be compacted. The compaction equipment used shall be all or any of the following: Heavy grid rollers, impact rollers, sheepsfoot rollers, tamping rollers, heavy pneumatic-tyred rollers, flatwheel rollers, vibratory rollers. and any other acceptable equipment. On

27、 completion of the compactton of the trial section at least 10 dry density measurements shall be made in the top 150 mm of the layer, or, in the case of non-plastic eand, in the Layer that lLes between 100 mm and 250 mm below the surface, and the average of these taken as the proof density. PSDM 1.2

28、.4 Determination of density not practicable_. Where, becauae of a high percentage of rock particles. the determination of in-situ densities is impractlcahle, the Engineer may, notwith- standing that the density is not specified and cannot be determined, order that the matertal be processed and compa

29、cted with at least the compacttve effort specified in PSDM 1.2.3. PSDM 1.2.5 Variation In naterials. If, in the opinion of the Engineer, the characteristics of new materials vary sufficiently to warrant the determination of ra new proof density, he may order that more or fewer passes of the equipmen

30、t than specified in PSDH 1.2.3 be used. PSIIM 1.3 Measurement and payment PSDM 1.3.1 Compaction on basis of proof rolling. Where measurement is on the basis of proof rolling and the unit of measurement is the cubic metre, it will be assumed that in each cubic metre 6.5 layers, of thickness each appr

31、oximately 150 mm, have been subjected to 12 passes of the comblnation of compacting equipment (i.e. 80 passes per cthlc metre). The rate for proof rolling shall cover the cost of compacting a layer of thickness 150 mm. Where the actual thickness of the layer on which the proof density is established

32、 dif fers from 150 mm, payment will be adjusted according to whether more or less than 80 passes per cubic metre of material are required to estab lish the prooE density. The tendered rates for proof rolling shall cover the cost OF at least two passes each by a vibratory roller and an impact rolier,

33、 i.e. 4 passes of the 12-pass roller combination. PSDM 1.3.2 Where determination of in-situ density is impracticable. Material processed and compacted as specified in PSDM 1.2.4 will be measured and paid CO; as compaction to a percentage oE proof density except that the Contractor will be paid for a

34、nd he required to apply only the twelve passes of any combination of compaction equipment specified in PSDM 1.2.3 with adjustment in payment, where applicable, for any variation in compactive effort that the Engineer may have ordered. PSDM 1.3.3 Dealing with variations in materials. Where, in terms

35、of PSDN 1.2.5, the Engineer orders that a new proof denity be determined by the use oE more or fewer passes of the equipment than are spectlied in PSDW 1.2.3, a pro rata adjustment in payment will be made, The acttal number of passes used by the Contractor to compact the material to 98 X of such new

36、 proof density will not be taken into account wben the adjustment in payment to the Contractor is determined. SABS 0120 : Part 2 Section DM-1981 Earthworks (roads, subgrade) PSDM 1.3.4 Scheduled items for compaction (Subclause 8.3.3). Compaction will be measured and paid for as set out in (a) or (h)

37、 or (c) below. a) Six-pass roller compaction using 1) Heavy pneumatic-tyred roller Unit: m2 2) Vibratory roller Unit: m2 3) Impact roller . Unit: m2 The rates shalt cover the cost of subjecting the road-bed to six passes of the respective campactor, including the cost of providing the rollers and of

38、 holding them in readiness for the time when soil moisture conditions are favourable. b) Road-bed preparation and compaction of the material to a minimum of 98 X; of proof density . Unit: m3 The rate shall cover the cost of detenining the proof density in addition to the cost of the operations speci

39、fied in Subclause 8.3.3 of SABS 1200 DM. c) Cut to fill, borrow to Pill compacted to 98 X of proof density Unit: m3 The rate shall cwer the cost of determining the proof density in addition to the cost oE the oerations soecified in Subclause 8.3.4 of SABS 1200 DM. d) Eriat ions in com active ef Fort

40、: 1) Vibratory rollersP . . Unit: m2.pasa . 2) Impact rollers . Unit: d.ass . 3) All other rollers Unit: nz.ass Item (d) shall apply to (a), (b), or (C), as applicable. The unit will be computed by multiplying the area to which the variation applies by the increased or decreased number of roller pas

41、ses by which the speciEied effort has heen increased or decreased on the order of the Engineer. in relation to the specified number of passes. The rate shall cover the relevant operations specified in PSDM 1.2 and PSDM 1.3.1-1.3.3. Any increase or decrease in the area or number of passes (or both) w

42、ill be added or deducted at the appropriate rate when payment is made. 3.2.2 Amended Requirements for Materials. Where for economic reasons or where the nature or size of a project is such that the required properties of the materials require amending, include in the project specification clauses su

43、ch as the following: PSDM 2. USE OF MATERIALS PSDM 2.1 Minimum CUR for fills over 12 m high (Subclause 3.2.2). The Eill material in the lower layers of fills higher than 12 m shall be PSDM 2.2 Strength requirements for selected layer (Subclause 3.2.3). For the selected layer the Contractor may use F

44、ill material that has a P1 of . (NOTE: Maximum PI = 3 x grading modulus + 10.) 3.2.3 Crushing and Screening. Where necessary, include a method of breaking down the oversize material by crushing and screening in a clause such as the Following: PSDM 3. CRUSHlNG ANI) SCREENLNG (Subclause 5.2.4.2(c) PSD

45、M 3,l Processing selected layer material by crushing and screening (Subclause 5.2.4.2(c). Where approved by the Engineer, material to he used as the selected layer shall be passed through a) a single stage crusher to break down the material to the maximum size specified in Subclause 3.2.3 of SARS 12

46、00 DM; or h) a screening plant to screen out the oversize material. PSUM 3.2 Measurement and payment for crushing and screening of selected layer gravel a) Provision of cruehing or screening plant. or both: 1) Single stage crusher Unit: No 2) Screeninn plant . Unit: No -. 3) Crushing and screening p

47、lant h) Re-erection of crushing or screening plant. or bolh: 1) Single stage crusher . 2) Screening plant 3) Crushing and screening plant . c) Crushing and screening: 1) Single stage crushlng 2) Screening . 3) Crushing and screening Measurement and payment will be made as specified in SABS 1200 ME U

48、nit: No Unit: No Unit: No Unit: No Unit: m3 Unit: m3 I . Unit: m3 1) Subbase. SABS 0120 : Part 2 Section DM-1981 Earthworks (roads, subgrade) 3.2.4 Construction of High Fills (Subclause 5.2.4). The construction of high fills may require special techniques to prevent the development of excessive pore

49、 pressure and to ensure the stability of such fills during and after construction. These techniques may include, inter alia, the selection of better class material for use in the lower layers of the Pill, the construction of sand blankets, and the strict control of moisture content during compaction. Where Fills are designated as high fills and such measures are required include clauses such as the following in the project specification: PSDM 4. SAND BLANKETS FOR NIGH FlLLS PSDM 4.1 Construction. A sand blanket consisting of a layer of selected sand having a grading such that