Method-Statement-for-Road-Works-(道路施工方案英文)

1、精选优质文档倾情为你奉上精选优质文档倾情为你奉上专心专注专业专心专注专业精选优质文档倾情为你奉上专心专注专业METHOD STATEMENT FOR ROAD WORKSTABLE OF CONTENTSS.NoDescriptionPage No1.0Scope32.0Permits and Licenses 33.0Methodology (Sequence of Work For Surface Water Drainage Works )34.0Health and Safety315.0Risk Assessment356.0Environment Control397.0Inspe

2、ction and Testing398.0Supervision Responsibilities409.0Resources4010.0Drawings and Sketches4211.0Reference Documentation4212.0Attachments431.0 SCOPE The purpose of this Method Statement is to describe the Methodology involved in construction of Road Works in accordance with project technical specifi

3、cations, international standards and codes, local rules and regulations (QCS-2010). This method statement will cover the following works:Earth Works Preparation to Road FormationGranular Sub-base Preparation WorksAsphalt Works2.0PERMITS AND LICENSES The Permits and License required for commencement

4、of the work shall be obtained prior starting any site activities, the permits and license shall be obtained from the Following: Electricity and Water AuthorityTel-communication OperatorMunicipality GovernmentMinistry of EnvironmentPublic Work Authority (Roads)3.0SEQUENCE OF WORKS FOR ROADS3.1 Site p

5、reparationPrior to commencement of work, the contractor shall obtain the relevant work permits from ClientThe contractor shall under take clearing of site in order to remove any existing vegetation; steel, concrete, unused buildings identified for demolition, piping debris, loose windblown sand and

6、otherforeign materials.All existing structures, foundations, etc. as indicated above shall be entirely demolished, removed, transported and disposed of by the contractor to a debris yard designated by Client. All soft spots left shall be filled with suitable material and compacted as per specificati

7、on.Excavated material, if any, and suitable and approved by Client forbackfilling shall be transported and placed in fill areas within the limits of the work. 3.2 Survey and Setting Out3.2.1 Survey MarkersSurvey Markers shall be durable, appropriate to location and intended use. Survey Markers shall

8、 be clearly identifiable and protected from construction traffic. For installation of a Survey Marker into reinforced concrete, the JVs will ensure that steel reinforcement bars are to be avoided. Either removable anchors or epoxy adhesive shall be used as the methods of fixing Benchmarks are a part

9、icular type of Survey Markers used in the control of elevation.Benchmarks shall have a domed surface for unambiguous staff placement. Primary Benchmarks shall comprise a stainless steel bolt securely placed vertically into a concrete slab, or horizontally into a column. The protrusion shall not pose

10、 a safety hazard. Survey Markers used for horizontal control shall have an unambiguous point above (or below) which a survey instrument can be precisely centered. The point shall comprise either a punch mark or the intersection of 2 lines forming a cross. Cross-headed road nail (75mm long) complete

11、with a colored washer shall generally be used as a Survey Marker. 3.2.2 Control Observation, Adjustment and PresentationHomogeneous horizontal and vertical survey control is required prior to any setting out. Survey control shall evolve from the whole to the parts. Where practical, all survey points

12、 within a horizontal survey control network shall be occupied and observed from. Forced centering techniques shall be used throughout. A round of angular observations shall comprise the mean of observations taken on both faces of the total station. A minimum number of 4 rounds of horizontal and vert

13、ical angles shall be observed at each instrument set up. For control work, the angular spread of horizontal angles shall not exceed 3 of arc. Distances shall be measured in both directions. All raw data pertaining to each set up shall be electronically recorded. Survey control shall include redundan

14、t observations. Observation networks shall be processed using the method of least squares adjustment and the resulting residuals to the observations shall be inspected for magnitude. Any large residuals or error ellipses shall be examined and appropriate remedial action shall be taken. Precise level

15、ing shall be double run using equal back and fore sights at each instrument set up. Leveling sights shall never exceed 30 meters. On the ground surface, the Contractor shall establish stable bench marks adjacent to the site so that the distance between adjacent benchmarks does not exceed 250 meters.

16、 Height datum transfer accuracy shall be better than 2mm in a 30m deep shaft. The transfer of height datum shall be by various independent means. azimuth transfer from surface to underground shall be better than 3“ of arc and point transfer shall be accurate to within 2mm. Such transfers shall be by

17、 various independent means. At 3 month intervals, the Contractor shall conduct a complete survey of all existing survey control. A bound, A4 size survey control report shall be submitted to the Engineer for acceptance within 2 weeks of completing the field work.The convention adopted shall comprise

18、Station Name, Easting, Easting, Northing and Elevation reading from left to right report shall contain the following information report shall contain the following information: dates of survey, fixed survey control and values, specification of instrumentation used, calibration status of instrumentat

19、ion used, observational acceptance criteria, list offinal adjusted co-ordinates findings and conclusion.Attached to the report shall be the observations (A4 print out of electronic booking sheet or customized spread sheet), adjustment with residuals and station error ellipses, table of differences i

20、n mm from previous co-ordinates and elevations (if applicable),a drawing clearly showing layout of scheme and measured quantities and final co-ordinates in tabular form.3.2.3 General Setting OutThe Contractor shall carry out a comprehensive level survey of the Contract area before any work commences

21、 on the site that may alter original ground levels.Pre-computation shall be carried out prior to any setting out. For rail projects, the effects of cant and throw shall be incorporated into pre-computation wherever relevant. All pre-computation shall be readily available in a spread sheet format for

22、 use on site. The method of setting out for each particular element of the work shall commensurate with the required accuracy, the method of construction, and shall be appropriate for site conditions.In the setting out process, all elevation transfer conducted by leveling shall start on an establish

23、ed benchmark and finish on a different benchmark. If a significant disclosure is detected, the reason shall be determined and the necessary corrective action taken. After the erection of the formwork and prior to concreting, a survey check shall be carried out on the formwork to ensure that the sett

24、ing out has been done correctly. A spreadsheet shall be used in all instances to tabulate the difference (or offset) in mm between the actual set out (or as-built) co-ordinates from the design co-ordinates. In cases where the design is an alignment, offsets to the alignment shall be computed for eac

25、h surveyed point.3.3Earth Works3.3.1Earthwork GeneralThe JV will carry out all earth work in such a manner as to prevent erosion or slips and shall limit working faces to safe slopes and height.The JV will ensure that all surfaces have at all times sufficient gradients to enable them to shed water w

26、ithout causing erosion.Hauling of material from cuttings or the importation of fill material to the embankments or other areas of fill shall proceed only when sufficient compaction plant is operating at the place of deposition to ensure compliance with the requirements of Client.Construction traffic

27、 other than that required for the excavation and trimming shall not use the surface of the bottom of a cutting unless the cutting is in Rock or the Contractor maintains the level of the bottom surface at least 300 mm above formation level.Any damage to the sub-grade arising from such use of the surf

28、ace shall be made good by the Contractor at his own expense with material having the same characteristics as the material which has been damaged.The JV will arrange for the rapid dispersal of water shed on to the earth works or completed formation during construction, or which enters the earth works

29、 from any sourceThe JV will provide where necessary temporary water courses, ditches, drains, pumping or other means of maintaining the earth works free from waterThe JV will take special care that naturally occurring materials within the site are not rendered unsuitable by his method of working. Ar

30、eas of cuttings and excavation shall be so worked that rainfall is conducted rapidly away from the exposed material and at times of expected heavy rain that the cutting areas are protected by appropriate methods of working and drainage provisions.3.3.2Classification of Earth Work MaterialThe followi

31、ng definitions of earth works shall apply to this and other clauses of the Specification in which reference is made to the definitions:Top Soil shall mean the top layer of soil that can support vegetation.Suitable Material shall comprise all that is acceptable in accordance with the Contract for use

32、 in the works and which is capable of being compacted in the manner specified in project Technical Specifications to form a stable fill having side slopes as indicated on the drawings.Not Suitable Material shall mean other than suitable material and shall include :Material from swamps, marshes or bo

33、gs;Peat, logs, stumps or other organic matter and perishable and toxic materials;Material susceptible to spontaneous combustion.Clay of liquid limit exceeding 80 and/or plasticity index exceeding 55.Rock shall mean hard material found in ledges or masses in its original position, which would normall

34、y have to be loosened either by blasting or by pneumatic tools, or if excavated by hand, by wedges and sledge hammers. Rock shall also include all solid boulders or detached pieces of rock exceeding 0.10 m 3 in size in trenches or exceeding 0.20 m 3 in general excavation.3.3.3Excavation Excavation w

35、ill be carried out to the dimensions, lines, levels and slopes as indicated on the IFC Drawings.If the JV excavates deeper than the depths shown on the Drawings or as instructed by the Client, then he shall fill in such excessive depths with acceptable materials to the satisfaction of the Client.The

36、 bottom of all excavations shall be free from mud and water, trimmed clean, protected from the effects of weather and thoroughly compacted and consolidated The JV will be responsible to excavate to the top of soft or defective soil below the formation level and backfill with Suitable Material. Such

37、backfill will be well compacted in layers of accepted thickness by approved manners and means.3.3.4Cuttings and Cut SlopesUnless otherwise specified, no portion of the earth cutting shall vary from the specified or ordered formation level by an amount exceeding 150mm.In the case of cut slopes, no po

38、rtion of the completed slope shall vary by an amount exceeding 100mm (measured at right angles to the slope).In all cuttings, whether in earth or rock, undulations in the general plane of the slope will not be permitted. Unless otherwise specified, excavation in rock shall extend to at least150mm be

39、low the specified formation level and backfilled with approved materials. Any overhanging, loose or unstable material shall be removed. The excavation shall be so arranged that the working areas are adequately drained throughout the period of construction. In cutting where the strata consists of ear

40、th overlaying rock which is required to be cut to a slope of 1 (H): 2 (V) or steeper, the face of the rock shall be given its appropriate slope up to the junction of the rock and earth and the latter shall be stripped to form a bench 900mm wide and sloped to the gradient as specified.3.3.5Maintenanc

41、e of Excavated AreaContinuously monitor the dimensions / level of excavation to avoid over Cutting if any accidental over cutting takes place, fill and compact with Suitable material to the desired level. Remove any undesirable material (vegetation, organic soils etc.)Encountered during excavation a

42、nd fill with approved granular material.Take necessary measures to keep the excavation free from water by De-wateringwherever required.Arrange shoring so that it does not interfere with the progress of work andFunctioning of nearby facilities as work proceeds, remove the shoring carefully without ca

43、usingany danger to the excavation.If any accidental slips or settlement occurs in the excavated area, Properly fill by selected fill or with mass concrete.3.3.6Sloping the Sides of ExcavationWherever there are chances of sliding, properly slope sides of Excavation.Trim the slopes by hand to uniform

44、batters as shown on the IFC Drawings.Trim any rock or boulder appearing in the face of the slope, and remove italtogether, if it seems unstable.If any rock is removed, fill the resulting void with compacted material.Imported Rock Fill shall be clean well-graded quarry waste provided by the Contracto

45、r from sources outside the Site. It shall be resistant to weathering, to the acceptance of the Client. The maximum size particles in the material shall pass through a rigid 200mm square grid and the largest dimension of any particle shall not exceed 300 mm. The material shall not have more than 10%

46、of its particles passinga0.75 mm BS sieve.Fill Material shall mean Suitable Material for backfilling with the exception of Rock and Imported Rock FillSpecial Fill Material shall mean Suitable Material of which at least 95 per cent shall pass a 125mm BS sieve and at least 90 percent shall pass the 75

47、mm BS sieve. Up to 5 per cent of the material may be made up from isolated boulders of maximum dimensions not exceeding half the thickness of the layer of material being placed. Liquid limit not exceeding 35plasticity index not exceeding 12(h) Selected Fill shall be well graded granular natural sand

48、s, gravel, crushed rock, crushed concrete, well burnt shale or other materialsaccepted by the Client. The material passing a 425 micron BS sieve, when tested inaccordance with BS 1377, shall have a plasticity index of less than 6%.Imported Fill Material shall be Fill Material supplied by the Contrac

49、tor from a source outside the Site and accepted by the Clients.3.3.7 Compacting and Levelling the FillDuring compaction, maintain the M.C of fill material, usually +/- 3 Percent of OMC. IfRequired, add clean water to the fill material in order To maintain the necessary M.CAchieve minimum density of

50、specified M.D.D. of soil, by using roller / Plate compactor or any other approved equipment.Around new (or existing remaining) concrete foundations or other Substructures doNot compact by rolling. Instead, use mechanical Rammers or plate compactors to Compact the space in vicinity of Concrete struct

51、ure.After compaction, level the surface free from undulations using suitable Equipment.3.4 Materials forSub-base3.4.1Fine Aggregate for Sub-BaseFine aggregate (Passing the 4.75 mm sieve) shall consist of crushed mineral aggregate and/or natural sand.The fine aggregate shall be clean and free from or

52、ganic matter, clay balks and other extraneous or detrimental materials.The ratio of aggregates passing the 0.075 ram sieve shall not exceed 66% of the portion passing the 0.425 mm sieve.The material passing the 0.425 mm sieve shallhave a maximum liquid limit of 25% and the plasticity index shall not

53、 exceed 6%.Where the source of fine aggregate does not meet the above requirements, with the Engineers approval, add fine aggregate and filler to correct the gradation or to change the characteristics of the material passing the 0.42 mm sieve so as to meet the requirements. Such additional material

54、shall be added in a manner which ensures a completely homogeneous material3.4.2Coarse Aggregate for Sub-BaseCoarse aggregate (retained on the 4.75 mm sieve) shall consist of crushed stonecrushed gravel with minimum of 50% by weight having at least one fractured face.The flakiness index of the aggreg

55、ate shallnot exceed 35% when tested in accordance with BS 812.The Los Angeles Abrasion Loss, as defined by ASTM C131/C535, shallbe 40% maximum.The aggregate type for the sub-base shall be crushed limestone.The coarse aggregate shall be hard and durable and free from organic matter, clay and other ex

56、traneous or detrimental materials.Coarse aggregate shall have a maximumloss of 20% by the magnesium sulphate soundness test when performed as per ASTM C88 for 5 cycles.The minimum CBR value obtained when preparing samples of aggregate base and aggregate Sub-base at optimum moisture content and at 10

57、0% relative compaction and soaking them for 4 days shall be 80% and 60%; respectively. The maximum permitted swell shall he 0.5% and 1.0%; respectively3.4.3 Mix Design for Sub-baseAggregates sub-base shall consist of crashed mineral aggregates or natural mineral aggregates of the designated gradatio

58、n and thickness.The maximum dry density and the Optimum moisture content of the material shall ascertained as per the test procedure given in CML 12- 97 andthis shall be used to assess the degree of compaction of the mix after rolling170-7.5.66The pavement layer designated as sub-base, the material

59、shall conform to Class B or Class CThe particle size shall be determined by the washing and sieving method of BS 812: Part. 103.Fine and coarse aggregates for sub-base shall be combined gradation of material that meets the requirements of the specification for density and other properties,The aggreg

60、ate bases shall conform to the class A or class B gradation and the aggregate sub-base shall conform to the class C gradation, as given in the following Table:BS Sieve mPercent PassingClass AClass BClass C36100-5090-100100-37.560-9070-100-2524-7755-851002035-7050-8090-1001026-6040-7050-85515-4030-60