英文版深基坑土方开挖施工方案WPforEarthworkExcavationofMainPowerBuilding

1、BIssue for ApprovalAIssue for ApprovalREV.DESCRIPTIONDATEDESIGNED BYCHECKED BYREVIEWED BYAPPROVED BYOWNERVIETNAM ELECTRICITYTHERMAL POWER PROJECT MANAGEMENT BOARD 3CONSULTANTPOWER ENGINEERING CONSULTING JOINT STOCK COMPANY 3CONTRACTORTHE CONSORTIUM OF CHENGDA-DEC-SWEPDI-ZEPCSUBCONTRACTORZHEJIANG THE

2、RMAL POWER CONSTRUCTION COMPANYPROJECT:DUYEN HAI 3 THERMAL POWER PLANT PROJECTCONTRACT NO:DH3-05082011DOCUMENT NAME:Working Plan for Main House ExcavationPROJECT CONTROL NO.: DH3-31U-C-WP-0002REV: B Contents1 Project Overview12 Reference Standards and Codes13 Construction Preparation13.1 Technique P

3、reparation13.2 Labor Power Preparation13.3 Machinery Preparation23.4 Material Preparation23.5 Working Surroundings Preparation23.6 Working Schedule24 Main Method & Technique Measures34.1 Construction Sequence & Methods34.2 Slope34.3 Steel pile44.4 Drainage of Foundation Pit64.5 Foundation Pit Monito

4、ring65 Quality Assurance Measures65.1 Organization chart of QA/QC65.2 Flow chart of quality problems treatment75.3 Specific measures86 Supplement of Guarantee Measures to the Schedule86.1 Establish a Strict Censorship for Construction Schedule86.2 Warranty the Supply of Materials & Outward Processin

5、g Components86.3 The Coordination Work Between Civil Engineering & Equipments Installation97 Safety & Civilized Construction98 Attachment Drawing118.1 Drawing of excavation for #1 main house118.2 Layout of Drainage measures for #1 main house foundation pit128.3 Steel Sheet piles survey points layout

6、 for #1 main house138.4 Survey Record for Foundation Pit148.5 Calculation for steel pile wall15Working Plan for Main House Excavation1 Project Overview Project Name：Duyen Hai 3 2x622MW Thermal Power Plant;The Owner: Power Generation Corporation 1The Consultant: Power Engineering Consulting Joint Sto

7、ck Company 3Design Overview: The project of Vienam Duyen Hai 3 Power Plant is located in Duyen Hai, Tra Vinh Province. Which the foundation is located on mud layer or sea sand layer. Raw geographical elevation is -2.37m, and underground water level is -3.8m.Main house of #1 unit includes Turbine hou

8、se and bunker bay, axis AD is 52.6m, axis 09 is 91m. The excavation cushion bottom elevation for foundation of main house are -4.1m、-5.1m、-6.1m、-8.4m, the excavation cushion bottom elevation for turbine house foundation is 9.4m, the bunker bay cushion bottom elevation is -6.1m.As for elevation of so

9、me foundation is below underground water level, and excavation is deep, it is required to stress on dewatering for deep foundation pit and slop reinforcement to ensure the safety construction.2 Reference Standards and Codes Unified Standard for Constructional Quality Acceptance of Building Engineeri

10、ng（GB 50300-2001） Code for Acceptance of Constructional Quality of Building Foundation (GB 502022002) Code for Engineering Surveying（GB 50026-2007）3 Construction Preparation3.1 Technique PreparationPrepare, review and approve method statement in accordance with procedures.Prepare ITP in accordance w

11、ith acceptance standard.Prepare construction start report, reviewed and approved by related departments.Organize related personnel for drawing joint review and technique enclosure, making record and archive.Before start work, perform technique and safety enclosure for constructors.Complete site hori

12、zontal control network and leveling point monitoring work according to the surveying control point supplied by construction unit. 3.2 Labor Power PreparationLabor required by this project is as following table:S.N.Type of workQuantityS.N.Type of workQuantity1Site management staff27Excavator driver42

13、HSE Personnel18Piling machine driver23QC Inspector19Other staff154Electrician25Surveyor46Truck driver163.3 Machinery PreparationMachinery and equipments by this project is as following table:S.N.NameTypeQuantity (unit)Remarks1Loader12Hydraulic excavator23Submersible pump2.2kw174Dump truck85LevelATO

14、3216Total StationNTS 312R+17Piling MachineType 4501For steel sheet piling work3.4 Material PreparationPlastic film：4000 m2；Sand bag：600 m；Scaffoldings：7 t；Fastening：1000 pieces；Water pipes：700m；12m steel sheet piles：160 pieces.All above material shall be traced in the whole construction process, and

15、 added if found not enough.3.5 Working Surroundings PreparationWater: lead from Phase 3 steel factory water pipes;Electricity: lead from II cabinet located in the southwest of phase 3 #1 boilerRoad: a concrete road used for transportation locates in the southwest of the working site;Temporary roads

16、are built by actual demands between the working site with the concrete road. 3.6 Working Schedule4 Main Method & Technique Measures 4.1 Construction Sequence & MethodsThe sequences & methods for various working parts are as following table:S.N.Working PartContents & Sequence1Bunker bay excavationExc

17、avated to the depth of -6.1m, adopt slope excavationusing plastic film to cover slope surfaceafter the excavation is completed, drainage ditch & pit are set at the bottom of the foundation for pumping water.2Turbine foundation axis ABExcavated to the depth of -4.1m，adopt slope excavationusing plasti

18、c film to cover slope surfaceafter the excavation is completed, drainage ditch & pit are set at the bottom of the foundation for pumping water.3Excavation for Turbine foundationB row of steel sheet piles constructionThe foundation of depth to -9.4m，The rest adopts slope excavation, vertical excavati

19、on for B rowusing plastic film to cover slope surfaceafter the excavation is completed, drainage ditch & pit are set at the bottom of the foundation for pumping water.See 8.1 for drawing of the foundation excavation4.2 SlopeThe slope of this project is as 1：1.5 according to the Code for Acceptance o

20、f Constructional Quality of Building Foundation (GB 502022002); the distance between the boundary of earthwork excavation with foundation boundary is: b= 0.6+0.3+0.3+1.5h, which h is excavation depth. See following sketch for details:Since the soil of the site has a good stability itself, reinforcem

21、ent measures need not to be taken for the slope during excavation.The slope covered with color band cloth preventing from rain. As following pic. shows :4.3 Steel pileTo assure construction progress, the foundation by the side of B should be supported with steel sheet piles。According to the data of

22、exploration & the manufacturers, the type & layout of the teel sheet piles are as follows:Type: 12m in length（See attachment 8.5 for calculation ）, 0.4 in width, 76.1kg/m, as following picture:Site layout of the steel sheet of piles is as picture 8.1；Install guide positioning bracket: it is installe

23、d for ensuring the verticality and level of piles. The enclosing purlins are welded by 2pieces of 20# U-steels in two-way, and the height for Installing guide positioning bracket is 2.5m, two theodolites are set for controlling the verticality. When the installation is completed, the beams of guide

24、positioning bracket cannot be sunk and deformed and shall keep vertical in the process of steel sheet piling.Steel sheet piling: the steel sheet piles shall be inspected before piling, vertical face shall be flat and alignment, and lock catch shall meet requirements, and be fixed if not. Meanwhile c

25、lose groove bottom in tip of piles with grease painted onto it to avoid mud into the lock catch. Crawler crane is used for piling, the steel sheet piles will be lifted to the inserting point by cranes, the lockcatch shall be in alignment when pitching of piles, pile cap and hardwood mat will be cove

26、red on top and piled normally. In order to ensure the verticality of piles, the piling shall be performed along with the enclosing purlins by using two theodolites for controlling. When start piling, the location and direction of the first and second pieces of pile shall be accurate for the function

27、 of guiding, they shall be measured for every meter into the earth. When it reaches the height of bracket, it shall be fixed by welding of steel plate with guide positioning bracket. After that, mark the position of each steel pile on steel enclosing purlings in convenient of correction at any time.

28、 If the pile is inclined in piling, steel rope will be used for pulling the piles, pulling, piling and correction by steps. When the first row piling finished, and be piled to the designed depth by second time. 4.4 Drainage of Foundation PitWater collection and drainage by ditches are taken for foun

29、dation pit drainage, see foundation pit drainage drawing for the drainage facilities. Bags covered with plastic film on the top of slope are used for stop water to prevent outside water from flowing into the pit. The bags shall be stacked closely with the gap filled by clayey soil.Width of 300mm dit

30、ch are set at the position of 600 mm higher the pit bottom, the depth of ditch at slope starting point is 300mm and the gradient is in 0.1%. 600mm600mm water collection pits are set along with the ditch, the distance between two pits is no more than 30m. The depth of water collection pit is 500 mm d

31、eeper than the ditch. And the water in the pit will be pumped outside.See attachment 8.2 for water stop, ditch and water collection pit arrangement.4.5 Foundation Pit MonitoringIn order to ensure the construction safety, displacement and settlement for steel sheet pile shall be monitored in the peri

32、od of foundation excavation and using.The layout of monitoring points: one monitoring point is set on the middle steel sheet pile, which both sides of 12m and 24 m away are also set monitoring points, the total quantity Is 5, see attachment 8.3 for monitoring points layout.Method of monitoring point

33、s: when the construction of steel sheet piling is completed, one small hole on the top of pile drilled by nail is considered as the monitoring point for displacement and settlement.Monitoring: The initial value shall be measured in the 12h after the completion of foundation pit excavation; And in th

34、e 3days after the initial value measured, it shall be measured once in each day; and after that once one week.See attachment 8.4 for Table of monitoring record.5 Quality Assurance Measures 5.1 Organization chart of QA/QC Project ManagerProject Chief Engineer Deputy Project DirectorProject Quality in

35、 charge Specialized person for quality inspection of projecttechnical person in charge Specialized person for quality inspectionTeam technician Surveying teamMaterial management teamMachinery dispatching teamUnskilled workers5.2 Flow chart of quality problems treatmentIf any quality problem is found

36、, it is required to be treated as followingfind quality problems or quality accident confirm the protective measuresinvestigate the said above Analyze cause unclearimplement the protective measuresclearInvestigate more, and analyze the cause furtherno need to treat treat or notneed to treatconfirm t

37、reatment plandesign or constructioninspection and acceptanceconclusionsubmit the treatment plan 5.3 Specific measures5.3.1 Surveying and LayoutTotal station and level used for surveying shall be calibrated with calibration certificate.Sideline shall be re-surveyed in the process of excavation to ass

38、ure the accurate excavation position.5.3.2 Earth work100 mm above elevation of foundation pit basement shall be excavated by manpower to avoid disturbing the basement soil and lowering its load capacity. Under-excavation and over-excavation are not allowed.If over-excavation happens, it shall be bac

39、kfilled with the material permitted by the Owner/Consultant, and the compaction factor shall meet the design requirements.ITP for Earth Workshall be implemented. 6 Supplement of Guarantee Measures to the Schedule6.1 Establish a Strict Censorship for Construction ScheduleThe construction progress and

40、 the time for each kind of workers joining into the work shall be controlled in accordance with the network plan, the management shall arrange construction sequences in accordance with aggregate scheduling. Check everyday construction progress and finish everyday work in schedule, ensure todays work

41、 will not affect tomorrow, this process will not influence next. The site manager will take command by himself for key part which affect schedule.6.2 Warranty the Supply of Materials & Outward Processing ComponentsOrganize personnel making subproject and item project analysis sheet, and processing,

42、procurement and supplying plan for material, production and semi-production. Ensure the machinery allocation work and material procurement and supplying. Determine time for material enter-site according to the Drawing of Construction Scheduling Network Plan.6.3 The Coordination Work Between Civil En

43、gineering & Equipments InstallationThe civil engineering & equipments installation working team need to cooperate in construction, and protect each others production and semi-production. A coordination meeting is required to hold by project manager once a week to solve the problems for cooperation a

44、mong various of works. Construction groups with many years of construction experience are selected for this project. And complete the management organization. Arrange labor power and material supplying reasonably and improve construction efficiency according to the construction schedule network plan

45、. Distinguish primary and secondary parts according to the the characteristics of this project, interchange the work in accordance with construction sequences and technology to assure the project is done on schedule.7 Safety & Civilized ConstructionThe personnel shall wear safety helmet when enter i

46、nto the site.All the constructor shall wear required safety shoes when enter into the site.Power distribution by classes and three-phase five little system for power distributing line are taken in site. Forbid to stay wire without permission. One break for one electric equipment, one leakage circuit breaker for one distribution box, use standard distribution box to ensure ele