GRBCC MS BXCV a1( box culvert)

Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN CONTENTS General Scope of Work and Locations 3 Construction Schedule 4 Site Organization Chart Material Equipment and Tools Construction Procedure Quality Control 16 Safety Control 17 10 Environmental Control 18 APPENDIX Appendix - Construction Schedule (03 paged Attached) Appendix - Construction Sequence for Box Culvert (01 page Attached) Appendix Appendix - Typical Drawing of Formworks - Inspection and Testing Plan (01 page Attached) (01 page Attached) Appendix - Inspection Sheet and Checklist (12 pages attached) Total: 41 pages page Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN General This Method Statement is to describe the work procedures for the construction of Underpass Box Culvert and Drainage Box culvert This work item shall be done in accordance with Section 06950 of the General Specifications Detailed Drawings indicate Detour/Temporary Waterway, Layout of site and Construction Schedule for each location of Box Culvert shall be submitted separately Scope of work and Locations The scope of work and locations of Underpass Box Culverts are as follows: No 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 Station Km191+960 Km192+890 Km194+486 Km195+912 Km196+460 Km196+832 Km200+700 Km201+658 Km202+354 Km203+420 Km204+319 Km204+610 Km205+415 Km206+239 Km206+865 Km207+452 Km207+609 Km207+834 Km208+040 Km208+400 Km208+835 Km210+141 Km211+035 Km211+565 Km211+983 Km212+473 Km213+015 Dimension 2.7*4m 2.7*4m 4.5*7.5m 2.7*4m 2.7*4m 2.7*4m 4.5*6m 2.7*4m 4.5*6m 2.7*4m 2.7*4m 2.7*4m 4.5*6m 2.7*4m 4.5*6m 2.7*4m 2.7*4m 2.7*4m 2.7*4m 2.7*4m 4.5*6m 2.7*4m 2.7*4m 4.5*6m 2.7*4m 2.7*4m 2.7*4m Length 62.00 53.68 16.04 15.99 27.31 45.58 29.76 13.25 13.25 65.45 46.84 22.15 18.11 24.90 13.25 13.72 13.25 13.25 13.72 13.25 13.25 35.09 24.87 13.71 13.25 13.25 13.25 page Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 28 29 30 31 32 33 34 35 Km213+625 Km214+230 Km214+440 Km214+856 Km216+244 Km216+697 Km217+277 Km217+980 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN 2.7*4m 2.7*4m 2.7*4m 2.7*4m 4.5*6m 2.7*4m 3.2*5m 4.5*6m 13.25 13.25 13.25 25.7 13.71 25.23 15.31 31.25 The scope of work and locations of Drainage Box Culvert are as follows: No 10 11 12 Station Km192+930 Km195+674 Km197+032 Km200+862 Km202+380 Km203+408 Km204+770 Km206+360 Km210+120 Km211+051 Km211+543 Km217+355 Dimension 3*3m 2（3*3m（ 2*2m 2*2m 2(3*2m) 2(3*3m) 2(2*2m（ 2(3*3m) 3*3m 2(3*3m) 2（3*3m（ 2(3*3m) Length 88.42 59.93 61.51 52.49 92.01 87.19 91.33 60.61 86.50 49.53 46.61 50.30 Construction Schedule Overall Construction Schedule and Detail Schedule for typical box culvert are attached in Appendix In addition, Box Culvert work shall be indicated and updated in monthly and weekly schedule For each location, Detail Schedule shall be submitted together with working drawing Site Organization Chart Organization Chart for management and construction of box culverts is as follows: page Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN Material List of required material for construction is shown below: No Material for Description Detail Backfill Excavated Soil / Borrow Material Blinding Stone Lean Concrete Crushed Rock or Cobble Stone Class G - Unreinforced Conc Concrete Class C-2 Strength - 30MPa - Conform to S06100 Reinforcing Steel bar CB400-V, CB204-T Conform to S06400 Granular Material Sand Conform to S03200 Cut off Plates (Water stop) Material proposal shall be submitted separately Joint filler PVC Pipes Refer to Submmited MS of Structure Excavation (GRBCC-MS-STEX-A7EN) 100mmØ for weep holes 10 Gavanized Wire Mesh Mimimum Diameter of 3.05mm, Tensile Strength of 4200~5980Kg/cm2, For Gabion Basket Opening shall not exceed 100mm 11 Rock 100~200 mm in size For Gabion Basket page Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN When stored at site, materials such as rebar and PVC pipes must be kept off the ground and shall be covered by vinyl sheet Other materials used for backfilling and blinding stone shall be timely transported to the site Equipment and Tools List of required equipment and tools for construction is shown below: page Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN Construction Procedure 7.1 Typical Construction Flow page Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN Typical Construction Flow (Continue) 7.2 Work Sequence Typical work sequence sketch is shown in Appendix Box Culvert shall be divided into several segments (as indicated on approved shop drawing) and each segment shall be constructed one by one The description of each segment work item is shown as follows: 1) Preparatory Works Construction of Box Culvert shall be commenced after shop drawing, method statement and working drawing have been approved from the Engineer Confirmation of approval for working drawings and preparation of working area shall be carried out before execution of work Survey line marking and layout for Box Culvert shall be established Mobilize all necessary materials and equipment before execution of work 2) Making Detour/ Temporary water way, Soft soil replacement For underpass box culvert located at existing road Detour must be made to ensure traffic during construction of Box culvert Detour shall be designed and constructed with suitable width and curve Connection between detour and existing road must be smooth Safety signboard and turning lamp shall be installed at both ends of detour page Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN For Irrigation / Drainage box culvert that located at existing waterway, temporary waterway shall be made during construction of new box culvert Cross section of temporary waterway shall ensured that drainage and irrigation to be similar to previous situation Detail of Detour/Temporary waterway shall be shown on the working drawing and this temporary work shall be followed approved working drawing Soil replacement shall be followed approved shop drawing and approved method statement of road earthwork I- Construction of Base Slab 1) Excavation, Trimming Works, Blinding Stone, Lean Concrete Excavation and trimming works shall be carried out based on approved Working Drawing Survey marking shall be established prior for placing blinding stone Blinding Stone shall be placed following the Approved Shop Drawing and shall be compacted thoroughly to the satisfaction of the Engineer using portable compacting equipment or equivalent After placing blinding stone, Lean concrete shall be placed and casted as indicated in the Approved Shop Drawings Placing concrete shall be carried out either by direct pouring, using excavator or crane and concrete bucket For more detail of above works refer to Submitted Method Statement of Structure Excavation Note: Stability of slopes 1:0.5 shall be checked and approved by the Engineer prior to commencement of works The Contractor either shall perform an on-site test to validate stability or shall justify adopted slope angle by any means approved by the Engineer As to safety control activities on site, please refer to Section 9.3 and 9.4 2) Installation of Reinforcement Bar and Cut-off Plate for Concrete Base 2.1) Survey marking layout shall be carried out prior to rebar and formwork installation for concrete base 2.2) Rebar used for structures shall be in accordance with Specification of the Project and approved by the Engineer 2.3) Rebar, before and after fabrication, shall not be placed directly to the ground but firmly chocked and covered by nylon canvas to minimize all the external effects 2.4) Rebar shall be fabricated by cutting and bending machine at fabrication yard and shall be transported to construction site 2.5) Rebars shall be installed and fixed with wires in workmanship manner based on Approved Shop Drawings Rebar protection thickness shall be ensured by installation of pre-cast concrete spacer page Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN 2.6) Starting rebars for wall shall be installed and carefully protected from corrosion starting rebar shall be fixed during concreting of Base Slab 2.7) After installation, rebar must be inspected by the Engineer 2.8) Illustration of Cut-off Plate (Water stop) JOINT FILLER CONCRETE WALL SEGMENT NO.1 CONCRETE WALL SEGMENT NO CUT-OFF PLATE CUT-OFF PLATE & J OINT FILLER DETAIL Clip fastened to a rebar with a tie wire FORM CONCRETE WALL CUT-OFF PLATE SIDE FORM TIMBER SUPPORT FOR FIXING THE CUT-OFF PLATE FIXING OF CUT-OFF PLATE DETAIL As to safety control activities on site, please refer to Section 9.3 and 9.5 3) Installation of Side Formwork for Concrete Base 3.1) Side forms shall be installed based on the line marking at the surface of lean concrete 3.2) Forms support and bracings shall be installed and properly fixed Formwork and supporting system shall be ensured so that formwork is even without distortion and deformation during concreting 3.3) Installed formwork shall even and tighten to avoid water leakage during concreting which may influence the quality and appearance of the structure So the gaps on form page 10 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN joint shall be treated and filled by cleat 3.4) Prior to concrete, entire surface of formwork shall be oily coated for easy dismantling in the next stage 3.5) After installation, form alignment shall be carefully checked by survey works As to safety control activities on site, please refer to Section 9.3, and 9.4 4) Casting for Concrete Base of Box Culvert CA STING CO NCRETE OF BAS E SLA B 4.1) Supply of concrete, auxiliary equipments and tools shall be carefully considered to ensure continuous performance 4.2) Concrete shall be mixed at plant and shall be transported to site by concrete mixer trucks Mixer Truck’s tank must be rotated during transportation so that concrete shall not be segregated 4.3) Concrete slump and temperature shall be checked at site prior to concreting 4.4) Concrete of base slab shall be done by concrete pump and/or chute, crane and concrete bucket depending on site condition 4.5) Concrete shall be placed layer by layers with the thickness of 25 ~ 30 cm each layer During concreting, concrete shall be continuously compacted by vibrator to ensure concrete quality While compacting, end of vibrator shall be 10 cm embedded in the previous concrete layer to ensure adhesion between old layer and the new one page 11 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 50cm Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN 50cm 10cm30cm Vibrator New concrete layer Previous concrete layer 4.6) During concreting, formworks and supporting system shall be always supervised to prevent problems if any 4.7) As to safety control activities on site, please refer to Section 9.3, 9.4, 9.5, 9.6, and 9.7 5) Concrete Curing, Removal of Forms and Treatment of Construction Joint 5.1) Curing shall be done after concrete surface start dry Concrete surface shall be covered by wet burlap or vinyl sheets These burlaps or vinyl sheets shall be kept moisture during curing period Curing shall be at least days from finishing concrete Wet burlap Surface of concrete CONCRETE 5.2) Formwork removal can only be done at least day after completion of concrete casting for vertical structure After remove forms, concrete shall be covered by vinyl sheet for curing 5.3) Construction joint shall be chipped by steel brush and water to ensure loose concrete shall be removed until sound aggregate is exposed page 12 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Chipping of surface of construction joint Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN Rebar of wall Bottom slab 5.4) Prior to casting of the next lift, the previously cast concrete top surface must be covered with a pure cement mortar layer 5.5) As to safety control activities on site, please refer to Section 9.3, 9.4, and 9.7 II- Construction of Vertical Wall and Top Slab 1) Survey Marking for Vertical Wall of Box Culvert Survey layout for vertical wall of box culvert shall be marked on top surface of concrete base 2) Installation of Working Platform and Scaffolding for Vertical Wall and Top Slab Vertical wall and top slab shall be cast together For this casting procedure, stability and rigidity of formwork and scaffolding shall be checked carefully Scaffolding and working platform shall be installed prior to install rebar and formwork for vertical wall and top slab of box culvert As to safety control activities on site, please refer to Section 9.3, 9.4, 9.7 and 9.8 3) Installation of Rebars and Cut-off Plate for Vertical Wall of Box Culvert Reinforcing bar for vertical wall shall be installed and properly fixed with wires in appropriate position according to Approved Shop Drawing Concrete spacer shall be installed to ensure thickness of concrete cover Cut-off plate shall be installed and set on its proper position based on the submitted Shop Drawings 4) Installation of Inner Side Forms for Vertical Wall and Bottom Forms of Top Slab 4.1) Panel forms shall be set to its proper position using the lines marked on top surface page 13 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN of the box culvert base Bottom formworks for top slab shall be installed based on design elevation as referred to the Approved Shop Drawings 4.2) Shoring, bracing and form support shall be properly installed and fixed Gaps on form joint shall be treated and filled by cleat 4.3) Prior to concrete, entire surface of formwork shall be oily coated for easy dismantling in the next stage 5) Installation of Rebars and Cut-off Plate for Top Slab Rebar shall be installed in workmanship manner, arrangement and location of rebar shall be referred on Shop Drawings Cut-off plate and joint bar shall be installed and set on its proper position based on the submitted Working Drawings 6) Installation of Outer Side Forms for Vertical Wall of Box Culvert 6.1) Panel forms shall be installed following the survey layout 6.2) Shoring, bracing and form support shall be fixed properly 6.3) Concrete covering shall be checked 6.4) All forms shall be cleaned and free from dirt, dust, grease or other foreign substance and shall be applied with the form-release-oil 6.5) All gaps between the forms shall be treated and filled with cleat 6.6) Prior to concrete, entire surface of formwork shall be oily coated for easy dismantling in the next stage 6.7) Typical drawing of formwork is attached as Appendix 7) Concrete Casting for Vertical Wall and Top Slab of Box Culvert 7.1) Prior to casting concrete, the below items shall be strictly followed: - Mobile pump shall be used for casting concrete Plastic hose shall be provided and attached on the tip of mobile pump pipe to avoid the concrete segregation during casting - Cleaning inside the form and water shall be sprayed on construction joint - Resources of materials shall be checked such as supply of concrete and equipments - Concrete casting equipment shall be set-up and check its condition before casting concrete - Pouring guide level shall be established for finishing the top slab surface Pouring page 14 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN guide level shall be placed at the centerline transversely and a maximum distance of meter longitudinally 7.2) During casting, the below items shall be strictly followed: - Vibrators shall be used in workmanship manner in order to consolidate and compact the concrete properly Vibrator shall be applied to area of concreting on a vertical position at to10 sec at one place - Regularly check the verticality of forms and necessary adjustment shall be made immediately if displacement or movement on forms is found - Discharging concrete on wall shall be done layer by layer with a max of 50cm / lift - Concrete supply shall be closely monitored to avoid cold joint - Tightness of the formworks shall be inspected regularly by the pouring guards to make sure that there is no deformation or displacement of forms and rebar and leaks at the formworks If displacements occur, immediate adjustment shall be done to reposition the forms or rebar before concrete placing continues 7.3) After placing concrete, top slab surface shall be hand finished by trowel CASTING CONCRETE OF WALL AND TOP SLAB 7.4) As to safety control activities on site, please refer to Section 9.3, 9.4, 9.7 and 9.8 8) Curing and Removal of Forms 8.1) Just after removal of formwork and completion of finishing work, the entire exposed surface of the newly cast structure must be covered with vinyl sheet for curing 8.2) Formworks shall be removed after the concrete has achieved 80% of the designed concrete strength 8.3) As to safety control activities on site, please refer to Section 9.3, 9.4, 9.7 and 9.8 9) Finishing works for Concrete Surface Just after formwork removal, exposed wires and rebars used to support formworks in page 15 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN right positions shall be removed or cut off at least 2.5cm beneath the concrete surface Any edges or grout stains and all false work shall be treated Any minor voids, depressions and honeycombs shall be filled with cement mortar mixed in the same concrete proportions of the structure but without coarse aggregate Any excessively honeycombed structure portions shall be rejected, and then, upon receipt of the Engineer’s written instructions, shall be removed and constructed again at the Contractor’s expense 10) Removal of Working Platform Working platform shall be removed, after inspection and approval for the finishing works of concrete surface As to safety control activities on site, please refer to Section 9.3, and 9.4 III) Construction of Wing Wall and Apron Wing wall and Apron shall be commenced after finishing of all segment of box culvert This method is similar to method statement of Substructure So that Construction of Wing Wall shall be refer to Method Statement for Construction of Substructure (submit separately) IV) Backfilling and Compaction Refer to Submitted Method Statement for Construction of Pipe culvert V) Construction of Approach Slab Refer to Method Statement for Construction of Approach Slab (Submit separately) VI) Cleaning Up Site All excess materials and rubbish shall be removed and disposed leaving the site neat, tidy and acceptable to the Engineer  In Case of Emergency 15.1) If it is necessary to stop placing concrete before a casting is completed, make the surface flat until the last available batch of concrete, and make proper construction joint In case of rainfall, pooling water shall be removed from concrete surface before making the surface flat 15.2) Extra specimens for concrete compression test shall be taken from emergency stopped concreting area in order to confirm the strength of concrete at the corresponding section 15.3) In case of rainfall, all areas of concreting shall be covered by plastic vinyl sheet 15.4) If casting equipment breakdown, a standby casting equipment shall be utilized for concrete casting Casting concrete shall follow the direction initially poured Quality Control The whole procedure shall be thoroughly checked by the Engineer in charge for operation Quality control shall be carried out in accordance with this Method Statement and other applicable specifications Inspection and Test Plan and Inspection Checklist are attached as Appendix Inspection and Test Plan and Inspection Checklist are subject to revision in accordance with the instruction by the Engineer page 16 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN 8.1) Tolerance for Concrete Structures Tolerance for concrete structure is shown as below table: Box Culvert Center Position Top Level Invert Level Dimension Vertically Top Grade Irregularities Spacing of Reinforcement Concrete Cover ±5mm ±5mm ±5mm -10 to +20 in 300 ±2.5mm Wing Wall, Apron, Approach Slab ±25mm ±25mm ±25mm -6 to +13mm ±19mm ±13mm in 3m Within ±10mm Within ±10mm 8.2) Testing frequency of materials for concrete shall be complied with Section 06100 of General Specifications 8.3) Necessary tools shall be used such as level bar for controlling the elevation of concrete top surface during casting concrete 8.4) Sampling of concrete for compressive strength test shall be in accordance with Inspection and Test Plan 8.5) Slump test and temperature check shall be done on each concrete mixer truck delivered to site The slump tests shall be carried out in accordance with ASTM C143 Safety Control Safety control shall conform to Approved “Project safety control plan” and that method shall be part of this Method Statement Prior to start the construction work, the following particular matters are to be through to all members working in the construction site in order to complete the Box Culvert and construction efficiently without any accident or casualty 9.1) Joint Meeting Prior to start any activity, a joint meeting with relevant staffs shall be held for the purpose of general explanation on the whole contents of works as well as the method for the implementation of efficient work in accordance with this Method Statement 9.2) Instruction All workers shall wear Personal Protective Equipment (PPE) at all times, such as hardhat (helmet), safety shoes and working uniform 9.3) Prevention of Accident by Heavy Machine Only skilled operator shall be allowed to operate equipment on site In case of new operators, a test of skill shall be conducted first prior to his acceptance to the job Preventive page 17 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN maintenance check shall be done regularly at equipment working at site prior to full operation Stability of working area and foundation of equipment shall be checked particularly at locations of outrigger and track pad of cranes 9.4) Prevention of Accident of the Falling Object During handling of materials and equipment, it shall be tied up properly to prevent from falling Lifting wire ropes shall have designed capacity for heavy lifting Lifting wire of lifting equipment such as crane shall be carefully checked 9.5) Prevention of Accident of Electrocution Electric generating equipment shall be properly protected and properly installed with earth connection Electric wires shall be connected with electrical tapes to prevent electric leakage Only skilled operator shall be allowed to operate equipment on site 9.6) Prevention of Accident in Night Shift Works Sufficient quantity of lighting system shall be provided for night shift works especially installed at working platforms If necessary all of the surrounding working area shall be lighted up 9.7) Existing Facilities Existing facilities especially existing overhead electric line, water line, telecommunication line and other important facilities at surrounding area shall be taken with care not to damage 9.8) Working platform Working platform and access ladder shall be provided for work efficiency and safety as well 10 Environmental Control Environmental control shall conform to the submitted “Environment control and protection plan” That Method Statement and shall be part of this method statement Responsibility for surrounding environment during construction work and shall comply with 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 page 18 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN APPENDIX Overall Schedule of Box Culvert : 01 pages A4 size Attached Detail Schedule for typical Box Culvert : 02 pages A4 size Attached page 19 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN APPENDIX Construction Sequence for Box Culvert (1 sheet attached) page 20 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN APPENDIX Typical Drawing of Formworks (1 sheet attached) page 21 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN APPENDIX Inspection and Testing Plan (1 sheet attached) page 22 Noi Bai-Lao Cai Highway Project Package A7: Km190+420 – Km218+040 Method Statement For Construction of Box Culvert GRBCC-MSCBC-A2-EN APPENDIX (Inspection Sheet and Checklist) (12 sheets attached) page 23 ... For Construction of Box Culvert GRBCC- MSCBC-A2-EN General This Method Statement is to describe the work procedures for the construction of Underpass Box Culvert and Drainage Box culvert This work... Construction of Box Culvert GRBCC- MSCBC-A2-EN For Irrigation / Drainage box culvert that located at existing waterway, temporary waterway shall be made during construction of new box culvert Cross... Method Statement For Construction of Box Culvert GRBCC- MSCBC-A2-EN APPENDIX Overall Schedule of Box Culvert : 01 pages A4 size Attached Detail Schedule for typical Box Culvert : 02 pages A4 size Attached