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 5 Section DM-1981 Earthworks (roads . subgrade) PART 5 : CONTRACT ADMlNlSTRATlON SECTlON DM CONTENTS START OF CONSTRUCTION Cneral
4、 IMMBUIATFAY AFlXR THE HANDING OVER OF THE SITE . Six-Paas Roller Compaction . DURING CONSTRUCTLON Administration (Precautions to Minimize lle Dimensions of cuts . Disposal of surplus or unsuitable malerial Most economical use of material . In-place treatment Methods of Construction Drainage of rock
5、 cuts Placing Watering and mixing Addition of fine material to side slopes o Compaciion of rock fills . . Widening of side fills Compaction specified by numher oE passes . QUALITY CONTROL AND OTHER CONSIDERATlONS . Page Number aye) . . rock fi S. 1 . 1 1s I S 2 . 2 P 2 . 2 SABS 0120 : Part 5 Section
6、 DM-1981 Earthworks (roads, subgrade) SABS 1200 DM : EARTHWORKS (ROADS, SUBGRADE) NOTE: The clause numher(s) given at the heginning or after the heading oE a clause ia/are, unlhss otherwise stated. the numher(s) of the relevant clause(s) of SABS 1200 DM. START OF CONSTRUCTION GENERAL. For the purpos
7、es 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 AFPER THE HANDING OVER OF THE SITE SIX-PASS ROLLER COMPACTION (Subclause 5.2.3.3 and see also Subclause 1.1.1 of Section DM of Part 3
8、of the code). Where the preliminary testing has not been adequate, trial compaction runs should be made. at the earliest possible opportunity during conatruction, on each type of material encountered. DURING CONSTRUCTION ADMINISTRATION (PRECAUTIONS TO MINIMIZE DELAYS) Dimension8 nf Cuts (Subclause 5
9、.2.2.1). The contractor should, immediately after the nature of the material heing excavated has been disclosed, ask the engineer for instructions regarding the slope of the sides of cuttings and the depth to which cuttinge are to be taken. A similar request should be made regarding the dimensions o
10、f any cuts and regarding any in-place treatment that may be required below the level of the top of the subgrade, if possible before the excavation reaches the designated finished levels. Disposal of Surplus or Unsuitable Material (Subclause 5.2.2.5). The engineer may require that surplus material be
11、 used to widen fills or flatten slopes or for any other similar purpose. Such decisions should be given early to enahle the contractor to organize efficiently. Most Economical Use of Material (Suhclause 5.2.2.3(c). Economy in the use of material is not necessarily associated with the lowest contract
12、 price (for the engineer), or the highest profit margin (for the contractor). Such economy is the most economical use of available material to achieve the quality of construction required by the employer. The decision on how this should be achieved may be a matter of opinion. The engineer. represent
13、ing the employer, must decide. The contractor may resort to arhttration if he does not like the decision. In-Place Treatment (Subclause 5.2.3.3(b). The engineer should take drainage problems into account before ordering work that will disturb an existing road-bed. METHODS OF CONSTRUCTION Drainage of
14、 Rock Cuts (Suhclauae 5.2.3.1). In the interests of the contractor and of the quality of the finished work, any hollows in rock cuts should be linked for the purpose of drainage. Placing (Subclause 5.2.4.2). Where material can generally be broken down to a maximm sise of 150 mm, the thickness of the
15、 layer should not exceed 200 m after compaction except that. in the case of cohesionless sands, layer thicknesses of up to 400 m may be employed provided that the specified densities are attained over the full depth of compaction. Where, after the removal of grossly oversize material, the remaining
16、material cannot be reduced in size to 150 mm or less, the thickness of the layer should be auch that the maximum dimension of any particle does not exceed two-thirds of the thickness of the completed layer. Before he allows thicker layers than those specified above to be constructed, the engineer sh
17、ould satiafy himselZ that the specified densities can be obtained through- out the full depth oE each layer and that the layers will be uniformly compacted by means of the equipment that the contractor proposes to use. Watering. and Mixing (Subclause 5.2.4.2(e). The required amount of water should b
18、e spplied by repeated passes of tank trucks with distributors of approved pattern and capacity, or by sprinkler irrigation equipment. and should be thoroughly mixed with the material in the layer concerned by oieana of disc harrovs, ploughs, motor graders. or other suitable machines. Addition of Fin
19、e Material To Side Slopes of Rock Fills (Subclause 5.2.4.3(c). The contractor should establish, in advance, whether it will be necessary to add fine material to the side slopes of rock fills and, if necessary. he should add the fine material as the fill is being constructed. May 1981 Approved by the
20、 COUNCIL OF THE SOUTH AFRICAN BUREAU OF STANDARDS SABS 0120 : Part 5 Section DM-1981 Earthworks (roads, subgrade) Compaction of Rock Fills (Subclause 5.2,4.2(d) a) Depending on the nature of the material, a number oE combinations of roller mass. number of passes, and width of vibratory roller should
21、 produce adequate compaction with a satisfactory lock. b) Studies of compaction processes have shown that because of many interdependent factors such as area of application, speed of operation, methods of generating vibrations. and variations in grading, moisture content, and pore pressure of the ma
22、terial being compacted, there is no simple way of determining compaction potential from machine data. Nonelheless. the data set out in (c) and (d) below will provide some guidance for the contractor and the engineer particularly if the data are used in the light of the experience of the parties carr
23、ying out the work. c) h order that a satisfactory “lock“ should be achieved the type of vibratory roller used. the operating speed, the number of passes, and the thickness of the layer should be such as to satisfy the following formula: - 1200 (minimum) h xv where Pe = total static and dynamic force
24、 per metre of width exerted by the vibratory roller at the operating frequency given by manufacturer, kN/m n - number of passes required h - thickness of layer, m v - roller speed. m/s Operating frequencies should be limited to 1100 - 1800 vibrations per mintite and the value of the ratio Pe/h shoul
25、d be at least 120 kN/rnZ. d) Because values of Pe and v are not always readily available. the following table, which is based on data from various manufacturers of vibrating rollers. may be useful in indicating the number of passes of various rollers required for a layer of thickness 750 mm. Widenin
26、g of Side Fills (Subclause 5.2.4.1(b). In general, the widening of side fills should be restricted to Fills of depth not exceeding 1,5 m. However, where the engineer find8 it necessary, in order to dispose of material that has unexpectedly become available or surplus, to order that addi- tional mate
27、rial be tipped over the side of an exfsting fill without further shaping and finishing, he should also order that the existing slope be benched prior to tipping and he should be prepared to pay under Subclause 8.2.4.4 of SABS 1200 DM for such benching. Compaction specified by Number of Passes Number
28、 of passes for a 750 mm layer StatLc mass of roller, t General (See Subclause 3.2.1 of Part 2 of Section DM of the code). While it is not the intention that water be applied to the road-bed by the contractor when compaction is specified by number of passes, and while no rigid control of moisture wil
29、l be exercised during compaction, the contractor should nevertheless satisfy the engineer that every endeavour is being made to take full advantage of favourable soil moisture conditions during the rainy season and, as far as is possible, to carry out such compaction when theroad-bedis neither exces
30、sively dry nor excessively wet. Total applied force, kN Verifying of output of vibratory roller (See Subclause 3.2.1 of Part 2 of Section DM of the code) a) Vibratory roller. As verification in the field of the dynamic load and frequency of a vibratory roller is not practical and the engineer has on
31、ly the data provided by the manufacturer to rely on, neither the static load in kilonewtons per metre of roller nor the dynamtc load in cycles per minute have been speciEied in PSDM 1.1.2, as set out in Subclause 3.2.1 of Part 2 of Section DM of the code. QUALITY CONTROL AND OTHER CONSIDERATIONS The relevant recommendations of SABS 0157) should be applied to the subgrade for urban and industrial roads. -. 1) Quality management systems.
