MS road earthwork a1

Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks CONTENTS General - Quantity - 3 Construction Schedule - Site Organization Chart - Equipment and Workforce - Description of Materials - Construction Method 7.1 Working Flow 7.2 Construction Method - 8 Inspection and Test Plan - 24 Safety Control - 25 - 25 10 Environmental Control APPENDIXES Appendix-1 (Soft Soil Treatment Schedule) -Appendix-2 (Inspection and Test Plan) Appendix-3 (Inspection and Check Sheet) 31th May, 2010 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks GENERAL This method statement describes the Road Earthworks including Soft Ground Treatment work such as Geo-textile and Prefabricated Vertical Drain including Sand filling and Borrow Material (Embankment) which will be carried out in accordance with General Specifications Division 3: “EARTHWORK” List of document that will be submitted separately is as below: (1) Working Drawing (2) Proposal of Material (3) Subcontractor proposal (if any) (4) Detailed information of equipment and labor to be mobilized QUANTITY Estimated quantity (bidding quantity) is as follows But they are only for reference The design quantity will be made from approved working drawings The actual construction quantity will be shown on As-built Drawing Item Unit Common excavation m3 2,521,904 Rock Excavation to Fill m3 1,897,832 m3 1,035,623 m3 314,145 Unsuitable material Borrow Material Quantity Remarks CONSTRUCTION SCHEDULE Construction Schedule shall be referred to latest approved Overall Schedule 31th May, 2010 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks SITE ORGANIZATION CHART Organization Chart is as follow GRBCC Project Manager Construction Manager Quality Control Manager Site Manager Site Engineer QC Engineer Surveyor Sub-contractor (if any) – Road Earthwork Project Manager Site Manager Site Engineer Foreman Operator Worker EQUIPMENT AND WORKFORCE 31th May, 2010 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Road Earthworks of this project will be divide into five (03) section along alignment plan Scheduled Machinery to be mobilized for Road Earthwork for each section is as below section :1 no 10 11 Item Bulldozer Excavator Excavator Vibration Roller Tamping Rammer Dump Truck Dump Truck Water Pump Diesel Generator Lighting System Survey Instruments Description 180CV 1.4 m3 1.9 m3 12 54~80KG 15~23tons Class 8~10tons Class 2~4 inches 125 KVA Quantity Auto level, Total station nos 10 nos nos nos nos as required as required 12 nos nos as required set Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Dewatering Source of power Night work Survey work section no Item Bulldozer Excavator Excavator Vibration Roller Tamping Rammer Dump Truck Dump Truck Water Pump Description 110 ~140HP Class 0.7 ~1.0m3 Class 1.2 ~1.7m3 Class 12 54~80KG 15~23tons Class 8~10tons Class 2~4 inches Quantity nos nos nos nos nos as required as required nos 10 11 Diesel Generator Lighting System Survey Instruments 125 KVA Auto level, Total station nos as required set Description Quantity Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Dewatering Source of power Night work Survey work section no Item Bulldozer Excavator Excavator Vibration Roller Tamping Rammer Dump Truck Dump Truck Water Pump 110 ~140HP Class 0.7 ~1.0m3 Class 1.2 ~1.7m3 Class ~ 15tons Class 54~80KG 15~23tons Class 8~10tons Class 2~4 inches Diesel Generator 125 KVA 31th May, 2010 nos nos nos 9nos nos as required as required 10 nos nos Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Dewatering Source of power page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 10 11 Lighting System Survey Instruments Auto level,Total station Method Statement for Road Earthworks as required set Night work Survey work Note: Above stated quantity of equipments could be changed if any required and necessary Scheduled workforce to be mobilized for Road Earthworks and detailed information to be describe in “Checking record of Equipment and Labor at Site” will be submitted separately after DESCRIPTION OF MATERIALS The materials will be submitted to the Engineer for approval and material tests in laboratory will be implemented before commencement of embankment work under the inspection of the Engineer The general description of Embankment materials is as follows The detailed information for materials will be submitted separately as proposal of materials Description Borrow material Material Source of Material rock or Soil rock pit or Hill Soil  Embankment soil material < Tests in laboratory for Borrow material> - Sieve Analysis AASHTO T88 / ASTM D1140 - Natural Moisture Content ASTM-D2216 - Liquid Limit AASHTO T89 - Plastic Limit AASHTO T90 - Plastic Index AASHTO T90 - Test for moisture-density relation of soil AASHTO T180-D (maximum dry density & optimum moisture content) - Internal Friction Angle ASTM D3080 - Cohesion ASTM D3080 - Elastic Modulus or CBR AASHTO T193 - Organic content test: ASTM D2974 31th May, 2010 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks The frequency of test during construction is in accordance with Clause 3.7(f) under Section 03400 “Embankment Construction” in General Specifications, therefore the test frequency for Borrow Material cover for each sample lot (with 03 samples) / each borrow pit, submission and approval shall be required for one (01) sample lot (with 03 samples) / 1500m3 of filling soil at site The testing result of Borrow Material should be used for the classification of soil to be approved by the Engineer Borrow material will be chosen how to meet requirements and conditions to fill or backfill embankment as shown on drawings Backfill materials must not contain organic substances such as: leaves, weeds, roots and garbage Any backfil materials are classified according to soil classification system ( Vietnam Standard 5747- 1993 ) belongs to OL, OH or Pt which will not be used Classified materials like: GW, GP, GM, GC, SW, SP, SM and SC will be approved of suitable materials provided that they are reasonable and not separate characteristics Unless it has other regulations on the drawing of Contract or of other parts, classified materials are CH, Cl or MH which can be used to embank base The backfill soil material must be taken from approved source Before using, it must have approval notice of openning the pit by the text of Supervision Consultant and notice on material suitability  Embankment rock material Rock fragments and boulders with a largest dimension of 80 cm could be used for Embankment Construction depending on the proposed plan of the Contractor, reviewed and approved by the Engineer In the case the use of rock fragments and boulders is allowed by the Engineer, the filling material between the large rock fragments and boulders shall be finer material, composed of rock fragments, gravel, sand or soil, in accordance with material requirements CONSTRUCTION METHOD 31th May, 2010 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 7.1 Method Statement for Road Earthworks WORKING FLOW Preparation Work Clearing, Grubbing, Stripping, Removal of Tree Demolition (if necessary) Removal or Diversion Water/ Temporary relocation of stream channel A Confirmation of approved working drawing Inspection of Ground Elevation and Location, Material Test Inspection of Mobilization of Equipment and Manpower Inspection of Ground Condition Survey and Inspection of Site Clearing Boundary Inspection and Confirmation of Demolition Quantity and Trees to be removed (if any) Removal and Disposal of Unsuitable Material, Demolished Materials (if any) Confirmation and Approval of Subsoil layer by the Engineer Top Soil Disposal and Removal of Existing Trees (if any) Acceptance of Construction Items (Demolition, Site Clearing and Grubbing, Removal of Trees) Acceptance to move to the next construction stage Confirmation and Approval of the existing condition of watercourses to relative authority and Engineer with working drawing B (A) excavation work Define construction range Base excavation to designed level Ispectiom of transport of material and method Inspection of mobilization work of material and manpower Inspection and control of base excavation fraction Acceptance council Road construction (base course - pavement, drainage, curb) Structure construction (cast-in-situ bored pile, retaining wall) (B) 31th May, 2010 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Soft soil demolition Backfilling by borrow materials Embankment Trial compaction to grade embankment Base embankment according to designed level Method Statement for Road Earthworks Inspection of soil conditions after clearing Engineer’s confirmation and approval of soft soil demolition Survey and inspection of soft soil bound Inspection of soil conditions while demolition Inspection of slope condition while demolition Definition of unsuitable materials or suitable materials while demolition Inspection of drain system (if requiref and necessary) Inspection and approval of auxiliary soil conditions by Engineer Survey andofinspection of material positionsand andmethod level Ispectiom transport of Backfilling layer by layer to clearing level of of surrounding area Inspection of field density testing Inspection of area and level Check and acceptance of construction items Check and acceptance to move to next construction phase Acceptance council Road construction (base course - pavement, drainage, curb) Structure construction (cast-in-situ bored file, retaining wall) 7.2 CONSTRUCTION METHOD 7.2.1 CLEARING, STRIPPING AND DEMOLITION  Implemeting to mark position, area limit that need felling, cutting grass weeds, grubbing root of a tree, demolishing construction debris and submit Supervision Consultant before doing next work  Removing all barrages within construction range ( old culvert, brick, fence ) All above materials after being removed will be gathered tidily, when need be, it will bre reused  Before embankment construction, Contractor will submit writing proposal on construction program of testing compact band to Supervision Consultant and Employer to consider The purpose to define construction equipment line, number of requirement path, humidity control methods  Tree root holes, holes are created after removing other barrages will be filled by backfill materials suit technical standard and compact reachs stipulated compactness  Under embankment bed, at this position, regolith and unsuitable materials will be abandoned or designated to compact, all tree roots will be domolished at least 50cm under natural ground or at least 80 cm under the lowest pavement layer At cutting part, all tree roots, removed trunks are not less than 50cm from underfoundation base layer  31th May, 2010 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks  Removing regolith on areas designated to implement at 20cm depth under initial earth and at least 30cm under the lowest bottom pavement layer and this layer dug-out earth must be isolated other dug-out earth  Contractor will fill holes which were born due to disassembling construction of suitable materials to surrounding earth plan level, they must be compacted suits requirement in design document or direction of Supervision Consultant  Using safety methods and effective warning for construction area and arrange beacon at night if need be  Existing puplic works need confirming with fuctional agencies before implementing the work Plan of removing, demolishing need to have approval of Engineer and functional agencies Bedding surface will be filled and levelled after clearing, removal and demolition Regolith of clearing work, kind of material afterwards can be used for slope sodding of earth embankment or delimiter line, will be gathered and stored at suitable position Clearing work, removal, demolition of upper parts will be implemented carefully to avoid to damage and affect ground bed of embankment Cavity and space after clearing will be filled by approved and compacted borrow materials Water on earth foundation surface will pumped out by sinker pump or temporary sewer Morever, the above work will obey regulations according to article 02100- “ Site clearing” and article 02200- “ Demolition and Removal of existing structures and obstructions” stipulated in construction engineer direction and check and acceptance        31th May, 2010 10 The channels and ditches crossing the area of embankment will be treated as follows page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Check condition of existing Channels and Ditches Working Drawing for Approval (Relevant Authority) (case1) Diversion outside the area of embankment (case2) Clearing & Grubbing ~ Common excavation for installation of temporary drainage Dry up existing ~ clearing, stripping & demolition of existing channels and ditches Install temporary drainage on designed location to keep the watercourse Filling existing channels and ditches with suitable material, leveling and compaction as required Backfilling after installation of drainage with suitable material, leveling and compaction as required Next step The existing pond in the area of embankment will be treated as follows Check condition of existing Pond (with Engineer & relevant authority) Temporary dyke construction outside the area of embankment (In case that the pond is located within R.O.W., the temporary dyke is not necessary.) Dewatering pond water by pump Remove unsuitable material (mud, organic… ) with Inspection Backfilling void by approved embankment material with inspection (up to the Site Clearing Elevation of surrounding area) Soft Soil Treatment (if any) Embankment work 7.2.2 EXCAVATION 7.2.2.1 Common Excavation (a) Description Common Excavation shall consist of all excavation within the limits of the cleared area between the demarcations site clearing work as shown on the drawings or as directed by 31th May, 2010 11 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks  Rock ramp will be cut out in advance if Supervision Consultant requires Contractor must have plan on diameter, distance and load cut out holes in advance to have breaking point, and drill cut out hole in advance total depth of cut  Contractor has to demonstrate to Supervision Consultant through testing section 30 m is diameter, distance and load in accordance with permitted external sloping  In order to have stable and safe rock cutting, Contractor must split scale and prepare slope, demolish all debris and broken rock Contractor also have to demolish protruding rock because it is very dangerous for road user If Supervision Consultant requests, Contractor must demolish all debris and broken rock which lay outside slope range pile  Not less than two weeks before starting activities of shot-hole drilling or at any time Contractor propose to change shot-hole drilling method, Contractor have to submit Supervision Consultant blasting plan to consider Blasting plan must tell full information on diagram and shot hole drilling control, Contractor proposes two methods of control blasting and producing blast Blasting diagram contains information as follows: Proposing blasting station scope Plan and general section of proposal drilling model including free surface, burden, blast hole distance, blast hole diameter, blast hole angle, hoist height and drilling depth Loading diagram shows kind and quantity of explosive, detonator, used initiator Process of starting blast hole including delay of time and system Data sheet of manufacturer of explosive, detonator, initiator wil be used Blasting diagram consideration of Supervision Consultant will not reduce contractor’s responsibility on accuracy and suitability of plan when it is implemented on site  Safety method of blasting  Shooting mine must obey safety norm on blasting work is issued by State  Only allow to implement to shoot mine when finishing safety preparation work and having shooting mine licence of appropriate authorities, in which including :  Preserving and supplying explosive safely  Preserving, equipment construction safely in dagerous area  Protecting dangerous area, it has road signs, radar tracking station, command station within bound limit of blasting area  Inform local authorities and the people in advance before blasting and explaining home signal 31th May, 2010 14 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks  Checking and accepting blast holes, blasting net film before carrying out blasting according to regulations on checking and accepting of drilling and blasting mine  Contractor has to calculate specifically each position and geological condition of construction, construction plan, size, construction shape, construction plan, size and shape of foundation pit to define mine quantity for each blasting Bore hole quantity must be defined based on technical economic index In special case, having to get approval from Supervision Consultant, contrator must blast in shallow holes with small bore holes but must chose position and calculate specifically for each case  When executing of shooting mine, only allow to use kinds of explosives and blasting devices that get State’s allowance to use and employer’s approval If it uses kinds of explosives and blasting devices different from the State’s regulations, it must get licence of competent management services and using process, conserving, separate transporting  Datas and arrangement of explosive are mentioned in construction design but it must be readjust precisely after each time of testing blasting or first blasting  Explosive has to be transported by special-purpose device with high safety  Radius of danger area must calculated based on field condition and suit regulations of safety, conserving, transporting and using of explosive materials  Technology of drilling and blasting mine card must be grant by Department of labor, invalids and social affairs  There must be person who is in charge guides blasting works in any case Those who undertake to shoot mine are specialized and trained before carrying out construction  Before shooting mine, Contractor will implement some essential procedures such as: making a notice board of shooting mine time and blasting order at construction of guide of blasting work 7.2.2.3 STRUCTURAL EXCAVATION Prior to starting excavation operations in any area, the Contractor shall :  take steps on his own initiative to regulate the natural drainage of the water flowing on the surface of the ground, to prevent flooding of excavations; these works shall not be 31th May, 2010 15 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks paid separately but deemed to be included in the scope of this Specification Section 03200 “Structural Excavation”  ensure that all necessary Site Clearance and Demolition in that area have been performed in accordance with these Specifications; and  notify the Engineer sufficiently in advance of the beginning of any excavation so that cross-sectional elevations and measurements can be taken of the undisturbed ground under the Engineer’ supervision The existing ground adjacent to the structures shall not be disturbed without the permission of the Engineer  Road inposition: drive gauge pile to limit road base construction, define excavation slope limit, mark white painted piles, this limit is maintained and supplemeted during construction  Use bulldozer, excavator and combine with manual methods to implement parts tidily, road base excavation will be transported by dump truct to places which get agreements from local authority and consulting engineer, employer to abandon  Dug soil is fully utilized to embank base if it has good quality  Dug soil is depriciated sepatately level, each level has enough width, safe enough for machines to construct on  Trenches or foundation pits for structures or structure footings shall be of sufficient size to permit the placing of structures or structure footings of the full width and length shown The sides of trenches or pits shall be adequately supported at all times The elevations of the bottoms of footings as shown on the Drawings shall be considered as approximate only and the Engineer may order, in writing, such changes in dimensions or elevations of footings as may be deemed necessary to secure a satisfactory foundation  All rock or other hard foundation material shall be cleaned of all loose material and cut to a firm surface, either level, stepped or serrated as directed by the Engineer All seams or crevices shall be cleaned out and grouted All loose and disintegrated rock and thin strata shall be removed  Where the footing is to rest on material other than rock, excavation to final grade shall not be made until just before the footing is to be placed Where the foundation material is soft or mucky or otherwise unsuitable soil, in the opinion of the Engineer, the Contractor shall remove the unsuitable material and replace it with granular backfill as required by the Engineer This foundation fill shall be placed and properly compacted in 15cm layers up to the foundation elevation  Excavation material as suitable and approved by the Engineer shall be unutilized or removed from the site in case of redundancy  During time of constructing road base, contractor’s technicians will always check base surface slope by level gauge, ensure geometrical dimension, superelevation, level, road base width, even ratio, copactness of road in accordance with technical standard 31th May, 2010 16 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks  In case, when digging to meet special geological situation different from design document, construction unit informs Supervision Consultant, Employer to handle Drainage method in road base construction:  Ensuring of drainage during time of executing construction plays an important role, it has an great influence on construction and construction schedule,so contractor will pay special attention to this work  At positions of excavation base will be made slope when constructing for natural drainage or arrange service key way along the road in order to be good drainage When it rains, any sweating position on road surface will be immediately released by workers and machines  During the construction of road base, contractor always ensures to implement parts tidily Construction is carried out promptly in dry weather phase, make full use of convenient influences of the weather in the raining season on construction quality and construction schedele  Contractor will dig horizontal drain ditch system or vertical drain dich system to drain temporarily or permanently according to drawing at positions are requested to prevent water from blowing to road base during construction.We, contractor always ensure a suitable drainage system and will come into use before carrying out pavement works Contractor will tidy up and clean drainage ditchs so that they can flow freely during the time of execution and construction warranty  During construction of road base excavation, it needs to pay attention to safety mathods as follows:  Position for excavator to stand firmly, stably,reach and range of dipper must be suitable  Excavation slope must be maintained carefully, not let heavy lorries travel nearby excavation slope, easy to cause landslip and unsafe Paying attention to cofferdam structure: Trenches or foundation pits for structures or structure footings shall be of sufficient size to permit the placing of structures or structure footings of the full width and length shown The sides of trenches or pits shall be adequately supported at all times The elevations of the bottoms of footings as shown on the Drawings shall be considered as approximate only and the Engineer may order, in writing, such changes in dimensions or elevations of footings as may be deemed necessary to secure a satisfactory foundation After digging the base reach the height according to design Contractor will rip soil base, ensure humidity on the road, skim supplementally by roller if need be,compact to ensure topmost 30 cm reach compactness as required 31th May, 2010 17 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Each time afer finishing to dig soil, Contractor should inform Supervision Consultant of work result, and when Supervision Consultant has not yet approved of digging depth and base material characteristic, be not allowed to fill any base material or footing After finishing the work of digging road base, Contractor will combine with Supervision Consultant to take the minutes to check and accept finished works, carry out next construction phase 7.2.3 CONSTRUCTION BLINDING STONE  Blinding stone for use as a foundation for structures shall be provided as shown on the Drawings or instructed by the Engineer  The main component of the blinding stone shall be approved cobble-stone or crushed rock, of the maximum size compatible with the thickness of blinding stone as shown on the Drawings The minimum height of any stone as placed shall be cm Stone shall be closely packed by hand placing, to the dimensions shown on the Drawings, and then thoroughly rammed by mechanical rammer Smaller stone pieces of minimum size mm shall then be placed between the larger stones and the upper surface brought up to the finished level shown on the Drawings or instructed by the Engineer The completed surface shall then be thoroughly compacted to the satisfaction of the Engineer using a mechanical rammer or vibrating roller  At his own cost the Contractor may substitute some of the blinding stone with Lean Concrete to provide a level surface for subsequent placing of formwork or reinforcement 7.2.4 REMOVAL AND REPLACEMENT OF SOFT SOIL The removal and replacement of soft soil shall be carried out at the locations will be shown on approved working drawing Prior to removal of soft soil, Site clearing work shall be conducted and inspected to conform to Division “Site Clearing” of General Specifications Before removal of soft soil and after site clearing, temporary earth dyke and drainage shall be constructed around the soft soil removal area to prevent water from outside flowing into excavated area during removal of soft soil and backfilling by borrow material Slope of excavation is about 1:1 and it shall be in accordance with ground condition in order to prevent from collapse during excavation After completion of soft soil removal, surface at bottom of excavated area shall be repaired smoothly and natural soil condition shall not be disturbed Elevation, shape, dimensions and slope of excavated areas shall be measured, inspected and approved by the Engineer before backfill and all these data shall be shown on the As-built Drawings The backfilling shall be constructed layer by layer with approved borrow material The compacted thickness of the first layer shall be 20cm~30cm The second and next layers shall be backfilled with 20cm of compacted thickness respectively 31th May, 2010 18 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks The compaction for 1st layer and the succeeding layers shall be carried out using proposed vibration rollers or other proper equipment The compaction will continue until 95% of the maximum dry density is reached Inspection by the Engineer will be carried out for confirmation of in-situ density testing for each layer In-situ density test shall be implemented for each layer in accordance with AASHTO T204 or AASHTO T191 using samples at each 500m3 of filling volume or 1500m2 of filling area depend on which ever is lesser 7.2.5 BACKFILLING BY BORROW MATERIAL AFTER CLEARING 7.2.5.1 GRANULAR BACKFILLING Material The material shall be well graded crushed or uncrushed gravel, stone, rock-fill or natural sand or a well mixed combination of any of these Grading requirements for the material are as follows: Maximum size cm Passing 4.75 mm sieve 25% to 90% Passing 0.075 mm sieve 0% to 10% Plasticity Index 10 max Construction The granular backfill shall be placed in layers not exceeding 15cm (measured before compaction) and compacted to a density of 95% of the maximum dry density determined according to AASHTO T180-D 7.2.5.2 PERMEABLE BACKFILL Material Material shall be hard, clean, crushed rock or gravel complying with the following grading : Sieve Size 63 mm 37.5 mm 31th May, 2010 19 % Passing by Weight 100 85 – 100 19 mm – 20 9.5 mm 0–5 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Construction: The method of construction will be at the discretion of the Contractor, but details must be submitted for the Engineer's approval before commencement of the work All details of the permeable backfill shall be as shown on the Drawings and the degree of compaction shall be as instructed by the Engineer 7.2.6 EMBANKMENT  Prior to the construction of roadway embankments, all necessary surface drainage, clearing and grubbing in that area shall have been performed in conformity with Specification Section 02100 “Site Clearing” After topsoil stripping, Cohesive Material can be excavated underneath and deposited aside as a protection dyke or the stock for slope protection as directed by the Engineer  Before construction, site technical officer must redefine embankment level to find out defects ( if any ) and measure on detailed construction organization for sections which are submitted to Supervision Consultant and Employer for approval  Before embankment construction, Contractor will submit writing proposal on construction program of testing compact band to Supervision Consultant and Employer to consider The purpose to define construction equipment line, number of requirement path, humidity control methods  Pilot compact at site to be implemented until Supervision Consultant approves essential handling to attain requirement compactness Unification including kinds of roller, compact order and number of required compact to tamp ready thickness layer Soil moisture limit during compact is written down and foundation for checking compact work humidity at site  Where embankments are to be widened, slopes of the existing embankment steeper than to shall be prepared by removing all surface vegetation and stepped so that the new embankment is keyed into the existing embankment to the satisfaction of the Engineer Stepping shall be done by cutting horizontal benches in the existing slope to a sufficient width to accommodate placement and compaction operations and equipment; cutting of benches shall begin at the intersection of the original ground and the vertical cut of the previous bench The widened embankment shall then be built up in horizontal layers to the subgrade level where it shall be covered as soon as practical with subbase so that the widened area can be used by traffic as soon as possible, enabling construction to proceed on the other side of the road if required  Stepping and digging drain ditch always ensure to keep embankment surface dry  If contractor will carry out transporting backfill materials from field or from positions of utilized excavation soil ( ensure quality ) to construction position by dummp truck, heaping up suits calculation thickness ( ensure base course thickness after compact not exceed 20cm ), then using bulldozer combines with grader to aggrade according to required level Use vibrating roller to compact When first layer has required compactness, to impplement to check compactness, geometrical dimension with Supervision Consultant Engineer and Employer,only when getting allowance, it can carry our next layer  Base backfill material of carriage way is placed layers with thickness not exceed regulations in article 3.7( in condition backfill soil is still loose ) in article 03400, then 31th May, 2010 20 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks allow to implement compaction as regulated Supervision Consultant will check and accept compactness of backfill soil layer before filling another layer Effective skim equipments wll be used based on number of placed times to ensure uniform thickness before compacting When inplement compaction, each backfill soil layer must be adjusted and flattened to ensure even compactness If need be,it can supplement water to have required compactness Draining can be carried out by method of ventilation (ditch plough, keep airy, create ditch ) or other method satisfy requirements of Supervision Consultant At positions need covered or finned granular draining backing or other porous draining material, need to pay attention to avoid phenomena of two admixed material  Compaction work for layer and next layers will carry out by using roller proposed or suitable equipments and water ( if need be ) Compaction work will be implemented until have compactness of 98 percent for foundation base layer and 95 percent for layers under foundation base layer During construction, it pays attention to material humidity how material alwals to have optimal humidity,when compacting, if materials are too wet, it must dry then it is compacted, if materials too dry, water truck will be used to irrigate subsoil ( Note:irrigate like shower to have uniform humidity ) At positions that machines can not approach, they will be levelled by manual methods and compacted by small vibrator for each layer  Diagram of mechanism compact has two way: forward, backward compact and bend compact If it carry out bend compact, it must reduce translational speed of compact at bend and not compact residually.Path of vibrator goes longitudinally axis of embankment construction and from external edge to construction centerline, from low position to high one Distance from last compact point of vibrator to construction edge not less than 0,5m  For foundation base ( Required compactness K98% ), after leveling according to required thickness Use bulldozer and grader to level and compact preliminarily getting interest of geometrical dimension to ensure that embankment level will not affect above material layers  Leveling equipments and soil transporting equipments must be arrange in accordance with route and distribute each soil layer so that it can utilze fully effect of compact while moving those equipments, minimize wheel pot hole and diminish unsteady compact situation  Backing course surface must be homogeneous, even and has suitable cross slope to ensure that it drain well  If base is embanked that it has rubber phenomena, it must dig and scrap completely that rubber layer and recompact pit bottom, when it is checked and accepted, we shall embank like normal base and pay attention to execute promptly to utilized fully on days of dry weather Earth fill after compacting, use grader to level to turn into cross fall to drain  Embankment layers shall be compacted and shaped to a % grade from the center to both sides for drainage of rainwater during construction The grade of last two layers shall be gradually modified to obtain % grade below the pavement structure 31th May, 2010 21 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks  In case, it can not avoid to compact backfill material in flooding condition, contractor should submit Supervision Consultant his construction method, proposal to ensure compact coverage for Supervision Consultant to pass  Where placing and/or compaction of material under saturated or flooded conditions cannot be avoided, the Contractor shall submit to the Engineer for approval his proposed methods to ensure adequate compaction  To avoid interference with the construction of bridge abutments, wing walls and box culverts, the Contractor shall, at points to be determined by the Engineer, suspend work on embankment forming the approaches to any such structure until such time as the construction of the latter is sufficiently advanced to permit the completion of the approaches without the risk of interference or damage to the bridge works  Material for embankment at points inaccessible to normal compacting equipment shall be placed in horizontal layers of loose material not more than 100mm thick and thoroughly compacted by the use of tamper vibrator  In carrying embankments up to or over culverts and where required in the Contract up to or over bridges, the Contractor shall bring the embankments up equally on both sides If conditions require placing backfill or embankment appreciably higher on one side than on the opposite side, the additional material on the higher side shall not be placed until permission shall have been given by the Engineer and preferably not until the structure has been in place 14 days, and tests made by the laboratory/s under the supervision of the Engineer establish that the structure has attained sufficient strength to withstand any pressure created by the methods used and materials placed without damage or strain beyond a safe factor  Contractor will arrange transporting behaviour, level suitably backfill soil to utilize fully compaction work, minimize wheel pot hole and unsteady compaction situation  During construction, Contractor should pay attention to ensure traffic Have barricade sign and flagman to ensure traffic safety, when it is sunny, it always irrigates to prevent dust  If Supervision Consultant allows to use ashlar and stone block with maximum size 80cm, those stone must be ripraped from foundation base layer level 200cm, according to requirements on riprap and material compaction are stipulated in contractor’s proposal construction plan which is considered and passed Those kinds of stones must ripraped in embankment and far minimum 2m from embankment slope, distance among stone blocks must be ensured to carry out compacting reach required closeness of Supervision Consultant  All backfill materials and big ashlars are covered with a material layer or other material layers of thickness 20cm which are classified well ensure not to have stone with cm bigger size and have ability to fully cover all apertures to backfill layer surface of big ashlar These cover layers must be ensured required compactness as stipulated in this technical direction  During construction at the site, always ensure not affect producing activities and traffic activities in the area 31th May, 2010 22 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks  When finishing the work, must have acceptance certificate on geometrical dimension, compactness, flatness and other requirements of Supervision Consultant, we can next works Inspection and Test Plan “Inspection and Test Plan” is attached as Appendix-2 “Inspection and Check sheet” is attached as Appendix-3 The “Inspection and Check sheet” is subject to further revision if necessary following the Engineers instruction Checking backfill soil has to be conducted in two positions: - Material pit: Before exploiting material, it has to take testing sample to recheck some physico-mechanical properties and factors of collated materials with essential requirement - At construction: implementing to check regularly embankment process to ensure technological process and embankment quality Samples must be taken at important representative places, distribute homogeneously on plan It has to check compaction density compared to design requirement, when filling grit construction must check further gradation, depend on construction behaviour and design degree, also must check further coefficient, shear resistance of materials, shrinkage degree when carrying out compaction During soil filling, it must check compaction quality,number of check sample at field, calculate according to area (s.m) When recheck backfilling soil, it calculates according to quantity (c.m) and table Position is taken samples must distribute homogeneously on plot, upper layer and under layer must alternate ( fill plot ) Each layer after being compacted must be checked k Only allow to embank next layer if previous layer reachs design closeness requirement Table (Vietnam Standards TCVN 4447 – 1987) Kind of soil backfill soil quantity equivalent to group of check samples Clay, sandy soil and sand without gravel, grain 100 – 200 (c.m) Gravel, grain or sand admixed with gravel 200 – 400 (c.m) Kind of soil backfill soil quantity equivalent to group of check samples 31th May, 2010 23 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Clay, sandy soil and sand without gravel, grain 100 – 200 (c.m) Gravel, grain or sand admixed with gravel 200 – 400 (c.m) Safety Control “Safety Control Plan” shall be submitted separately and shall be part of this method statement Prior and during the execution of the Road Earthworks, basic safety precautions shall be implemented to work efficiently and to prevent any accident or casualty Particular Item for safety control is as follows No Anticipated Accident Traffic accident with third person Collision accident (heavy equipment & Truck) Wedged accident between equipment Electric Accident Person Accident Preventive Action  Setting signalman at entrance of site  Set signalman at each working site  Keep speed limit 20km/h in site  Set wheel stopper at the location of unloading soil  Notice and instruct worker the work description  Set safety fence around heavy equipment working area  Electric under ground shall be fully protected from electric leakage and shall be buried at least 40cm from the surface when electric line is crossing access road  Electrical equipment shall have earth or ground connection  Install warning sign or notice at locations of electrical connection and lines  Staff, worker and operators shall wear the Personal Protective Equipment (PPE) at all times during working  Maintain working site condition neat and tidy at all times 10 Environmental Control “Environmental Management Plan” shall be submitted separately and be part of this method statement Responsibility for surrounding environment shall be implemented during Road Earthwork and in compliance to the Condition of Contract and Vietnam’s National Law on Protection of Environment and other relevant legislation such as: Government Decree No.175/CP, Government Decree on providing Guidance for the Implementation of the Law on Environmental Protection, 1994 If any other problems occurred in the site, applicable counter measures or prevention action shall be considered immediately and executed as soon as possible 31th May, 2010 24 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Particular Item to be controlled is as follows Particular Item No Coarse particulate and dust to purlieus Noise and vibration to purlieus Water contamination Pollution Action to be taken  Spraying water on access road daily  Cleaning entrance of site (utility road)  All sand/ soil trucks shall be covered by canvas  Keep speed limit 20km/h or less in site  Motorized equipment is not allowed to operate from 10p.m to 6a.m near by residential area  Photo record of the actual situation of residential houses and existing utilities adjacent to construction site before construction in accordance with the plan of investigation which will be submitted separately  Investigation of above houses and utilities during construction  Install sedimentation pit before outlet, (if required)  Set safety fence around heavy equipment working area  Equipment shall be properly maintained to prevent the emission of large amount of smoke for air pollution  Used oil and lubricants shall be disposed properly to prevent water and air pollution \ \ 31th May, 2010 25 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Appendix-1 (Soft Soil Treatment Schedule) 31th May, 2010 26 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Appendix-2 (Inspection and Test Plan) 31th May, 2010 27 page Noi Bai-Lao Cai Highway Construction Project Package A7: Km190+420 ~Km 218+040 Method Statement for Road Earthworks Appendix-3 (Inspection and Check Sheet) 31th May, 2010 28 page ... nos nos nos nos as required as required 12 nos nos as required set Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Dewatering Source of power Night work Survey work section... Auto level, Total station nos as required set Description Quantity Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Earthwork Dewatering Source of power Night work Survey work section... Method Statement for Road Earthworks Road Earthworks of this project will be divide into five (03) section along alignment plan Scheduled Machinery to be mobilized for Road Earthwork for each section