The purpose of this method is to describe the methodology involved in construction work for the Boiler foundation item and to detail out the steps to be taken in order to meet the technical requirements of VP1 BOT Thermal Power Plant
Comment Response Sheet (CRS) Project Title Van Phong BOT Thermal Power Plant Project Document Title METHOD STATEMENT FOR BOILER FOUNDATION UNIT Document Type For Approval Document No VP1-1-L4-C-HBA-10046 Returned Status AC Prepared by CRS No VP1-1-L4-C-HBA-10046-A-CRS CRS Issued Date 08/05/2020 Engineer Construction Review Date Status O/C * Remarks 08/05/2020 Closed O No Section/ Page Owner’s Comment Response to Comment This MS is behind from MS for TG foundation Is the sub-contractor different from the subcontractor of STG foundation ? Does the sub-contractor has experience of Boiler foundation of same size ? Especially keeping method for quality control of massive concrete DHI is the prime contractor and has to manage strictly sub-contractors to keep the same quality of design, MS and construction work, although different sub-contractors Did DHI check this MS really ? -The sub-contractor of Boiler foundation is different to TG foundation L4 -The sub-contractor has been built some Boiler foundations which similar to this one in past For example: Duyen Hai extension thermal power plant, Qty=10000m3; Nghi Son thermal power plant, Qty=12778m3 -DHI sincerely reviewed MS and has full responsibility of quanlity How about Unit ? The method statement for boiler foundation unit will be submitted by another submission 08/05/2020 Closed O Stage ~ concrete volume is 2100 ~2700 m3 which is huge These stages should be divided in two stages to easily manage the measures for mass concrete like TG foundation DHI has calculated the concrete supply as well as checked with capacity of concrete batching, besides other method statements have been prepared to make sure the quality of massive concrete 08/05/2020 Closed O Page of Comment Response Sheet (CRS) This staging of pouring concrete is not adequate Stage 1, and is OK, but the last Stage concrete is restricted by Stage and concrete Then there must arise tension force and possibly cracked by shrinkage during hardening of massive concrete This is the common sense DHI has updated new procedure as following comments and sequence of Anchor bolts installation plan which is belonged to IHI 08/05/2020 Closed O Can not find de-watering system Please note that the buoyancy checking at +2.0mNDL, dewatering system is very important especially for SCC sump construction DHI will set up the ditch to collect water and arrange water pump 08/05/2020 Closed O This space is very narrow How can Re-bar & Formwork be constructed ? The vertical lean concrete will be cast before the next activities such as rebar and formwork installation 08/05/2020 Closed O 7 Is thickness of Lean concrete 50mm? If anchor frame for anchor bolts is fixed with lean concrete, 50mm is too thin Tolerance of excavated surface will be ± 20mm and thinnest lean concrete will be less than 30mm The thickness of lean concrete follows design drawing is 50mm, DHI makes sure the thickness which will be constructed (minimum 50mm) 08/05/2020 Closed O 8 Who will approve this and how will the approval request be submitted? DHI revised 08/05/2020 O Closed Is support bar re-bar ? Re-bar is not enough stiffness and unstable Steel sections should be used for support This is also HSE mater DHI uses proper chair bar which retain safety and enough capacity stiffness and stable 08/05/2020 10 If thickness of 3m and 1.5m foundation is poured concrete continuously, how is this portion constructed ? Please show the detail The lean concrete in the shape of chamfer will be cast in advance of rebar and formwork 08/05/2020 Note O Please provide chair bar in the bar bending schedule Closed O Page of Comment Response Sheet (CRS) Method of installation of Anchor bolts for Boiler structure is not shown These anchor bolts are very important for Boiler structure Please show it on detailed drawing Method statement of Bolts installation will be submitted by another contractor(IHI) DHI will coordinate to IHI for this matter on site 08/05/2020 Closed O 10 This support rebar is very flexible and must be moved during concreting Steel sections is better DHI has updated in method, the anchors will be added to make sure stable 08/05/2020 Closed O 13 12 How is this support bar fixed at the bottom ? Please show the detail DHI has updated in method drawing 08/05/2020 Closed O 14 14 To provide thermal calculation for the specific mass concrete block How to control the valued - cooling system inside the block is recommended and what will constructor if the real temperature exceed 70 deg C Please consider there is high difficulty to 08/05/2020 11 12 calculate exact heat of hydration DHI is all responsible to control concrete temperature as following related specification OPEN O Because the Contractor not assign a cooling system after pouring, request the Contractor to supplement the heat check of mix design to ensure the limitation of maximum temperature otherwise nothing can be done after casting 15 14 How is Metal mesh treated at the top re-bar, before new concrete pouring ? At top of rebar layer, DHI will use formwork to make the construction joint, when casting concrete next time, Contractor will chip the concrete to make rough surface 08/05/2020 Closed O 16 14 Additional condition, the difference temperature between points at 1m distance must be less than 50 deg (refer Art 6.6 - TCXDVN 305 for Mass concrete) How to check and control it? DHI has updated, the method of monitoring for temperature has been showed into method 08/05/2020 Closed O Page of Comment Response Sheet (CRS) 17 14 Show that concrete temperature will not raise more than 40C the concrete is placed there isOvery limited options to act if 08/05/2020 Please consider there is high difficultyOnce to check concrete temperature rises excessively ACI for example has exact heat of hydration DHI is all responsible to methodologies to calculate the temperature increase Heat of hydration might be available from the cement supplier or can be control concrete temperature as following related estimated based on the chemical composition of the cement specification 18 14 These conditions mean that the surface temperature may increase to 50C This is unlikely to be possible, especially with the water application during curing Cover top of surface by foam thickness 3cm, keep the side formwork until the temperature differential between the middle of concrete mass and any outer surface is under controlled 08/05/2020 O Closed 19 14 side vibration on formworks is recommended DHI has updated 08/05/2020 Closed O 20 14 There is no statement about production, transportation , pump car, agitating truck and etc for 2000 ~2700m3 concrete The calculation of concrete supply, transportation will be attached as an attachment 08/05/2020 Closed O 21 16 Show a calculation that tis assumption is correct It is very unlikely that the center of the foundation will be at air temperature after days DHI revised 08/05/2020 Closed 22 16 How long does the thermal monitoring take ? Please describe more for the thermal monitoring process DHI has updated 08/05/2020 23 16 Provide a calculation showing the temperature increase and then decrease of the mass concrete to ensure that it does not create a delay due to excessive temperatures DHI revised 08/05/2020 24 16 Lack of other works to complete the foundation such as coating, backfilling Coating work, backfilling will be submitted by other submissions to get approval 08/05/2020 O Closed O Closed O Closed O Page of Comment Response Sheet (CRS) 25 16 Measures for Massive concrete of Boiler Foundation (2,000~2500 m3) is different from TG foundation Ð1500 m3) DHI should manage the sub-contractors for the same measures of massive concrete Casting time for each stage of Boiler foundation must be more than 20 hours and then Temporary Tent should be used for sudden rain and direct sunshine -The calculation of concrete supply, transportation will be attached as an attachment 08/05/2020 Closed O -Plastic cover will standby near concreting area 26 16 It is not acceptable because risk assessments used to assess based on method statement of each task, difference method means difference risk how come the risk assessment from general concrete work can cover all the risk for the boiler foundation activities? EPC to prepare the risk assessment for boiler foundation activities as project requirement DHI has updated 08/05/2020 OPEN Please O refer to section 8.1 for detail comment 27 17 Please describe detail risk assessment as per circular 07/2016/TT-BLĐTBXH required Please noted that we not want to repeated every single MS to asking about risk assessment, Please your job properly then VPCL is not your consultant The job safety analysis was not in line with DHI risk management procedure It's repeated again, It's seems that no one from DHI's EHS team review this MS before submitted to VPCL DHI has updated 08/05/2020 OPEN O Please refer to section 8.2 for detail comment 28 33 How about Unit #2 - will we have different MS ? The method statement for boiler foundation unit will be submitted by another submission 08/05/2020 Closed O Page of Comment Response Sheet (CRS) 29 41 Present the lighting arrangement, team of worker for each shifts Additional Notes (if any) * O - Open, C – Closed 30 41 Please provide the calculation for concrete supplier/transfer backup plan to ensure the pouring concrete will be carry out continually Time schedule must be estimated properly The calculation of concrete supply, transportation will be attached as an attachment 08/05/2020 Closed O DHI has updated, the worker will arrange appropriately in accordance with site activities 08/05/2020 Closed O Page of AP APPROVED Approved AC APPROVED WITH COMMENT Contractor to revise the correction and resubmit NA NOT APPROVED Revise the correction and resubmit before proceeding RE REVIEWED Information acknowledged with no comment For Approval RC REVIEWED WITH COMMENT Information acknowledged with comments Note: Approval or comment does not relieve the Contractor of all obligations covered under contract Discipline: Date: Civil 07 Jul 20 B 22-Jun-2020 For Approval J.H CHOI K.S KIM D.H JEONG A 23-Apr-2020 For Approval J.H CHOI K.S KIM D.H JEONG REV DATE DESCRIPTION Approved Checked Prepared OWNER VAN PHONG POWER COMPANY LIMITED PROJECT Van Phong BOT Thermal Power Plant Project Status □Approved □Approved with Comment □Not Approved □Reviewed OWNER’S ENGINEER Pöyry Switzerland Ltd EPC CONTRACTORS IHI–TESSC–CTCI–DHI CONSORTIUM PROJECT DOCUMENT No Document title is unit 1, then attached construction drawing is unit 2? REV VP1-1-L4-C-HBA-10046 B DOCUMENT TITLE METHOD STATEMENT FOR BOILER FOUNDATION UNIT EPC EPC DOCUMENT No VP1-1-L4-C-HBA-10046 Doosan Heavy Industries and Construction 1|Page REV B VAN PHONG BOT THERMAL POWER PLANT PROJECT Table of Contents PREFACE - - REFERENCE - 2.1 Applicable Code and Standard - 2.2 Drawing and Method Statement - - MANPOWER & EQUIPMENT - - RESPONSIBILITIES - - PROCEDURE AND SEQUENCE - - CONSTRUCTION WORK - 6.1 Excavation and disposal - - 6.2 Lean concrete - 10 - 6.3 Reinforcement work - 10 - 6.4 Installation of embedded plate, box out (if any) - 13 - 6.5 Please supplement the concrete surface finishing method with Formwork - 14 and/or without hardener 6.6 Concrete work - 17 - 6.6.1 Construction Joint - 17 - 6.6.2 Massive concrete - 19 - INSPECTION AND TESTING - 24 ENVIRONMENT, HEALTH AND SAFETY (EHS) - 24 8.1 Risk assessment - 25 8.2 Job Safety Analysis - 54 Attachment #1 : Calculation sheet for Formwork - 64 Attachment #2 : Method Drawing - 65 Attachment #3 : Calculation for concrete supply - 66 - - - | Page Rev B VAN PHONG BOT THERMAL POWER PLANT PROJECT PREFACE The purpose of this method is to describe the methodology involved in construction work for the Boiler foundation item and to detail out the steps to be taken in order to meet the technical requirements of VP1 BOT Thermal Power Plant Project Van Phong BOT Thermal Power Plant Company/Owner Van Phong Power company limited(VPCL) Contractor DHI ITEM Boiler Foundation Unit REFERENCE 2.1 Applicable Code and Standard • ACI 347-Guide to formwork for concrete • ACI 304-Guide for measuring, mixing, transporting, and placing concrete • ACI 301-Specifications for structural concrete for buildings • ACI 318-Building Code Requirements for Structural Concrete • ACI-305R-Guide to hot weather concreting • ASTM C33: Standard specification for concrete aggregate • ASTM C94: Standard specification for Ready-mix concrete • ASTM C150: Standard specification for Portland cement • ASTM C494: Standard specification for Chemical admixture for Concrete • TCVN 1651:2008: Concrete reinforcement • Part III-2 Exhibit B1 Tech Spec Section • Part III-2 Exhibit B1 Appendix G Civil/Structure Technical Guideline • VP1-0-EPC-H-GEN-10511-Health, Safety and Environment Plan • VP1-C-L4-H-GEN-00003- HSE Risk Management • VP1-C-L4-H-GEN-00005- HSE accident and incident • VP1-C-L4-H-GEN-00009- Working at height • VP1-C-L4-H-GEN-00012- Lifting operations • VP1-C-L4-H-GEN-00020- Scaffolding • VP1-C-L4-H-GEN-00024- Hot work • VP1-C-L4-H-GEN-00026- Excavation • VP1-C-L4-H-GEN-00027- Permit to work - - | Page Rev B VAN PHONG BOT THERMAL POWER PLANT PROJECT 2.2 Drawing and Method Statement • VP1-C-L4-C-HBA-17501_ Boiler excavation drawing • VP1-0-L4-A-UYX-00201_ General Rebar Standards • VP1-C-L4-C-HBA-17101_ Boiler foundation plan drawing • VP1-C-L4-C-HBA-17102_ Boiler foundation section drawing • VP1-C-L4-C-HBA-17103_ Boiler foundation detail drawing • VP1-C-L4-C-HBA-17301_ Boiler foundation reinforcement drawing • VP1-0-L4-C-GEN-10007_ Method statement for General concrete work • VP1-0-L4-C-GEN-10008_ Method statement for Excavation and backfilling work MANPOWER & EQUIPMENT • Manpower mobilized for construction of the Boiler are listed as followings: No Position Quantity Site Manager 01 Site engineer 06 Safety supervisor 01 Surveyor 02 Crane operator 02 Roller operator 01 Worker 100 • Equipment mobilized for construction of the Boiler are listed as followings: No Equipment Unit Quantity Total station nos 02 Auto level nos 02 Crane nos 02 Excavator nos 02 Roller nos 02 Rammer nos 05 Plate compactor nos 02 Cutting machine nos 05 Bending machine nos 02 - - | Page Remark Rev B EXECUTION PLAN OF CONCRETE WORK - UNIT #2 STAGE #4: 03 PULVERIZER FDNS,Quantity: 543m3 WORKING PLATFORM TOP LAYER BAR 3000 DETAIL A CHAIR REBAR BOTTOM LAYER BAR JOINT FILLER JOINT FILLER SECTION EXECUTION PLAN OF CONCRETE WORK - UNIT #2 STAGE #5: Axis BB-BD, Quantity: 3034m3 STAGE #6: Axis BD-BF, Quantity: 2803m3 STAGE #7: AXIS BF-BH, Quantity: 1787m3 HANDRAIL WORKING PLATFORM DETAIL A TOP LAYER BAR TUBE Ø48 CHAIR REBAR 600 SUPPORT BAR LEAN CONCRETE 250 3000 SIDE BAR 600 3000 600 1500 600 CHAIR REBAR 0.5 BOTTOM LAYER BAR SECTION SPAPE OF CHAIR REBAR EXECUTION PLAN OF EXCAVATION WORK - UNIT #2 EXECUTION PLAN OF EXCAVATION WORK - UNIT #2 2.3 2.2 2.4 2.1 2.5 2.6 2.7 CONECTED FLYWOOD DETAL CONSTRUCTION JOIN GRAPHIC SCALE BOILER FOUNDATION 300 300 550 300 550 320 1220 1220 800 800 800 PILE SUPPORT Ø49 600 600 STEEL BOX 50x50x1.8mm SECTION 2-2 STEEL BOX 50x50x1.8mm 600 600 600 STEEL BOX 100x50x1.8mm 3200 600 STEEL BOX 100x50x1.8mm PLYWOOD 18mm 600 250 250 PLYWOOD 18mm 600 CONSTRUCTION JOINT AT TOP WALL 1220 SECTION 1-1 CONSTRUCTION JOINT AT BOTTOM WALL GRAPHIC SCALE BOILER FOUNDATION MS-DETAIL OF CONCRETE-FORM WORK VAN PHONG BOT THERMAL POWER PLANT PROJECT Attachment #3 : Calculation for concrete supply - 66 - | P a g e Rev B Tính tốn khối lượng bê tông thời gian đổ bê tông / Volume concrete and time Thể tích khối móng/Foundation concrete volume :Vi (m ) Số lượng bơm mẻ đổ/Quantity truck mounted line pumps: n1 = Năng suất bơm bê tông lý thuyết/Ideal Capacity per pumps car : Pide = 60 m3 /h/pump Năng suất bơm bê tông thực tế/Actual Capacity per pumps car : Pact = 42 m3 /h/pump pumps Thời gian đổ/Pour time: h1 = 24 h Tổng thể tích khối đổ/Total capacity : V2 = P x n1 x h1 = 3024 (m3) Hệ số an toàn/safety factor : V2/V1 Hạng mục/ Items Nội dung/Content 1) Kích thước/ Mat size bê tơng/ Concrete 2) Xe bơm bê tông/ Truck mounted line pumps 801 m2 2764 m3 (Strength: fc=30Mpa ) Năng suất/ capacity 42 m3/h/pump Số lượng/ quantity xe bơm/pumps (1 back-up pumps) 3) Xe bê tông/ Agitator truck ( 8m3/ car) See detail below 4) Thời gian đổ bê tông/pouring time 5) Total capacity (m3) 6) Hệ số an toàn / Safety factor 24 giờ/h 2764 1.1 m3 -Tương tự cho mẻ đổ khác/Similar to other casting stages Phân tích chu kỳ bê tơng / Analysis of cycle concrete supply Time periods table references from supplier Trạm/Batching Classification VIMECO Day Night 0.8 Time periods (min) Distance (km) 8.0 8.0 Transport 3.0 3.0 Waiting 5.0 5.0 Casting 11.0 11.0 Washing 2.0 2.0 Turn back 3.0 3.0 Total 32 32 Tính tốn số lượng xe bê tông 8m3 tối thiểu Chu kỳ xe 32 phút/Time periods 32 minutes Thời gian chờ + đổ = 16 phút (~42m3 /h cho suất xe bơm bê tông) Waiting time+casting=16minutes(~42m3 /h capacity of truck mounted line pump) ●16 ● Finish1 period start ● 16 Truck 0.8 Product Truck Total 32min Theo biểu đồ bơm cần xe (dự trù xe) Follow the chart: pump need concrete trucks (1 stand by) Dự kiến trạm cấp từ bơm nên số xe bê tông tối thiểu cần thiết cho trạm bảng bên VIMECO will arrange pump trucks hence, the minimum of concrete trucks which need to provide Batching Vimeco Distance(km) 0.8 Max time periods 32 Quantity of pump pumps Min agitator trucks Checking with the capacity of concrete supply from Vimeco As confirmation from Vimeco, Total of capacity of product Mix concrete is: Within 24 hours Tcap=T1+T2+T3= Conclusion: Tcap>V2 7920 m3 OK Page Checking the Pump truck and the concrete truck: Qpump truck= Qconcrete truck= nos 10 >9(as requirement) Page OK OK Tính tốn khối lượng bê tơng thời gian đổ bê tông / Volume concrete and time Thể tích khối móng/Foundation concrete volume :Vi (m ) Số lượng bơm mẻ đổ/Quantity truck mounted line pumps: n1 = Năng suất bơm bê tông lý thuyết/Ideal Capacity per pumps car : Pide = 60 m3 /h/pump Năng suất bơm bê tông thực tế/Actual Capacity per pumps car : Pact = 42 m3 /h/pump pumps Thời gian đổ/Pour time: h1 = 22 h Tổng thể tích khối đổ/Total capacity : V2 = P x n1 x h1 = 2772 (m3) Hệ số an toàn/safety factor : V2/V1 Hạng mục/ Items Nội dung/Content 1) Kích thước/ Mat size bê tơng/ Concrete 2) Xe bơm bê tông/ Truck mounted line pumps 801 m2 2537 m3 (Strength: fc=30Mpa ) Năng suất/ capacity 42 m3/h/pump Số lượng/ quantity xe bơm/pumps (1 back-up pumps) 3) Xe bê tông/ Agitator truck ( 8m3/ car) See detail below 4) Thời gian đổ bê tông/pouring time 5) Total capacity (m3) 6) Hệ số an toàn / Safety factor 22 giờ/h 2537 1.1 m3 -Tương tự cho mẻ đổ khác/Similar to other casting stages Phân tích chu kỳ bê tông / Analysis of cycle concrete supply Time periods table references from supplier Trạm/Batching Classification VIMECO Day Night 0.8 Time periods (min) Distance (km) 8.0 8.0 Transport 3.0 3.0 Waiting 5.0 5.0 Casting 11.0 11.0 Washing 2.0 2.0 Turn back 3.0 3.0 Total 32 32 Tính tốn số lượng xe bê tông 8m3 tối thiểu Chu kỳ xe 32 phút/Time periods 32 minutes Thời gian chờ + đổ = 16 phút (~42m3 /h cho suất xe bơm bê tông) Waiting time+casting=16minutes(~42m3 /h capacity of truck mounted line pump) ●16 ● Finish1 period start ● 16 Truck 0.8 Product Truck Total 32min Theo biểu đồ bơm cần xe (dự trù xe) Follow the chart: pump need concrete trucks (1 stand by) Dự kiến trạm cấp từ bơm nên số xe bê tông tối thiểu cần thiết cho trạm bảng bên VIMECO will arrange pump trucks hence, the minimum of concrete trucks which need to provide Batching Vimeco Distance(km) 0.8 Max time periods 32 Quantity of pump pumps Min agitator trucks Checking with the capacity of concrete supply from Vimeco As confirmation from Vimeco, Total of capacity of product Mix concrete is: Within 24 hours Tcap=T1+T2+T3= Conclusion: Tcap>V2 7260 m3 OK Page Checking the Pump truck and the concrete truck: Qpump truck= Qconcrete truck= nos 10 >9(as requirement) Page OK OK Tính tốn khối lượng bê tông thời gian đổ bê tông / Volume concrete and time Thể tích khối móng/Foundation concrete volume :Vi (m ) Số lượng bơm mẻ đổ/Quantity truck mounted line pumps: n1 = Năng suất bơm bê tông lý thuyết/Ideal Capacity per pumps car : Pide = 60 m3 /h/pump Năng suất bơm bê tông thực tế/Actual Capacity per pumps car : Pact = 42 m3 /h/pump pumps Thời gian đổ/Pour time: h1 = 21 h Tổng thể tích khối đổ/Total capacity : V2 = P x n1 x h1 = 2646 (m3) Hệ số an toàn/safety factor : V2/V1 Hạng mục/ Items Nội dung/Content 1) Kích thước/ Mat size bê tông/ Concrete 2) Xe bơm bê tông/ Truck mounted line pumps 801 m2 2403 m3 (Strength: fc=30Mpa ) Năng suất/ capacity 42 m3/h/pump Số lượng/ quantity xe bơm/pumps (1 back-up pumps) 3) Xe bê tông/ Agitator truck ( 8m3/ car) See detail below 4) Thời gian đổ bê tông/pouring time 5) Total capacity (m3) 6) Hệ số an toàn / Safety factor 21 giờ/h 2403 1.1 m3 -Tương tự cho mẻ đổ khác/Similar to other casting stages Phân tích chu kỳ bê tơng / Analysis of cycle concrete supply Time periods table references from supplier Trạm/Batching Classification VIMECO Day Night 0.8 Time periods (min) Distance (km) 8.0 8.0 Transport 3.0 3.0 Waiting 5.0 5.0 Casting 11.0 11.0 Washing 2.0 2.0 Turn back 3.0 3.0 Total 32 32 Tính tốn số lượng xe bê tơng 8m3 tối thiểu Chu kỳ xe 32 phút/Time periods 32 minutes Thời gian chờ + đổ = 16 phút (~42m3 /h cho suất xe bơm bê tông) Waiting time+casting=16minutes(~42m3 /h capacity of truck mounted line pump) ●16 ● Finish1 period start ● 16 Truck 0.8 Product Truck Total 32min Theo biểu đồ bơm cần xe (dự trù xe) Follow the chart: pump need concrete trucks (1 stand by) Dự kiến trạm cấp từ bơm nên số xe bê tông tối thiểu cần thiết cho trạm bảng bên VIMECO will arrange pump trucks hence, the minimum of concrete trucks which need to provide Batching Vimeco Distance(km) 0.8 Max time periods 32 Quantity of pump pumps Min agitator trucks Checking with the capacity of concrete supply from Vimeco As confirmation from Vimeco, Total of capacity of product Mix concrete is: Within 24 hours Tcap=T1+T2+T3= Conclusion: Tcap>V2 6930 m3 OK Page Checking the Pump truck and the concrete truck: Qpump truck= Qconcrete truck= nos 10 >9(as requirement) Page OK OK