Construction method statement

TEMPORARY WORKS PLAN CONTENT: I/ Site preparation and temporary facilities Ii/ material and equipment III/ execution drawings for temporary works asattached I- Site preparation and tempo

TEMPORARY WORKS PLAN

CONTENT:

I/ Site preparation and temporary facilities

Ii/ material and equipment

III/ execution drawings for temporary works (asattached)

I- Site preparation and temporary facilities:

Soon after receiving a letter of award, the Contractor will immediately prepare to set upthe construction site, promptly contact with local Authorities and Public TransportationService and related Services for construction permission for worker and machine Thetemporary facilities are including but not limited to the followings according to layoutdrawings for temporary facilities:

1 Grading, compacting, sewage and drainage, cleaning, safety board

Temporary site road will be setup to ensure site traffic is thorough, conventional and safe.Temporary site road with sufficient notice boards to be maintained during wholeconstruction period

During the construction time the Contractor will maintain and spraying water forrestriction of dust and keeping environment

2 Temporary water supply:

The point of water supply should be supplied by the Owner The Contractor may sign thecontract with local supplier for delivery water by tanker to site if necessary The deliveredwater will be contained in the temporary water tank on site and supplying for constructionexecution, curing, fire prevention and living through pumping and piping system

In case this source is insufficient, the Contractor plans to drill well

3 Site drainage and dewatering:

Site drainage shall be maintained for protection of the Work Site and ensure the cleanenvironment Storm water will be caught to manholes and sum pit before connected tothe local existing drainage system

4 Temporary power supply:

The point of power supply should be from the Owner The Contractor shall liaise withlocal Electricity Company for getting permission of using power resource of them Inaddition, the Contractor will provide standby generators: 30KVA for constructionactivities in case of shortage at each project The temporary lighting and power system on

site is setup above with rubber electric cables and connected to power points throughbreak and relay for safety.

Electrical net for site will be made of double-insulated cable (3x35+1x16) and stable hangabove ground, each electrical device must have circuit breaker and safety grounded

5 Temporary telephone system:

Temporary wireless telephone system will be setup at site offices after completion oftemporary buildings

- Because construction area is very large so difficult for establishing temporary fence

We will protect material and equipment by using cover storage with lock, increasenumer of guarder and guard houses for sercurity insurance, restriction of theconstruction activities and avoid inconvenience to other part of project

- Cleaned water tank, portable WC will be made

- Temporary accommodation area for workers will be located out of project site (made

of prefabricaed structure or house rental) The camp for worker will be kept clean,ventilated, dry and good looking

Ii- Preparation of material and equipment:

- Reinforcing bar is from Hoa Phat, VIS ect…that conforming to projectspecification.

- Ready mixed concrete should be from PVV batching plant or other at the local areamatching the Owner requirement

Contractor will conform to the specification and design, any changes will be reported tothe Employer for approval

* Exploitation, transportation, preservation:

- Contractor will establish a material and equipment team under QS department for thepurpose of material procurement

Materials delivered to site will be preserved carefully in cover area above the ground or in

a good manner

2 Equipment and formworks

Construction equipment will be mobilized to site according to the progress of works.Scaffolds and Formwork preparation:

Contractor plans to use steel prefabricated formwork for main structures combining withwooden supports and plank for small and non-standard structure form

Kind of scaffolds should follow manufacturer’s specification and calculation for eachkind of works Before making scaffolds system for slab Contractor will preparecalculation to submit to the Consultant for approval

WORK METHODOLOGY

CONTENT:

I/ work Methodology statement

1 Survey and benchmarks works

7 STRUCTURAL STEEL AND ROOF WORK

8 Waterproofing and test

9 Masonry, plastering and other finishing works

10 Plumbing and electrical work

11 conclusion

II/ execution drawings (as attached)

4

I/ work Methodology statement

1 Survey and benchmarks works:

1.1 Survey works:

The Employer already carried out soil investigations for each site Contractor will takeadditional steps necessary for familiarization with the site condition The siteinvestigation work shall be carried out using modern methods, equipment undersupervision of a qualified engineer

The Contractor will study and investigate the entire site In place of excavation, workersshall use manual investigation method by pressing under the ground and through thatgetting information about underground obstacles to find an appropriate solution

1.2 Benchmark works:

In parallel with survey works, Contractor will deploy the benchmark works of woodenpiles Main benchmark will be made by concrete pile outside the building so they will notinterfere to any works during execution of this building Make offsets 2 m from twodirection of this benchmark and they will be used for control of the Benchmarks duringthe construction works

2 pilling works

1 GENERAL :

Generally, the pile driving procedure will be accordance with the order as follows:

Preparation for implements:

- Site plan

- Equipment, pile driving machine

- The staff on site

To carry out works as follows:

- The order of execution

- Checking allowable tolerances

- Forms

Including steps as follows:

- Preliminary handing over before driving

1 PREPARATION

2 THE PILE DRIVING

EXECUTION

- Detailed handing over after completion

- Forms

Checking the following conditions:

- The pile set

- The cut off level

- The general ordinate of pile gridline

- The other load testsPREPARATION WORKS:

Preparation of site plan:

- Site plan should be cleaned preliminarily such as excavating brush, stump, removingobstructions, thin mud from site area Checking the underground systems informed by theClient or strange obstructions, bomb…

- To carry out improvement soil at the site to reach the necessary strength to bear the liveload of facilities, equipment, temporary static load of pile layers on the site plan Toconstruct a public road system, pile storage and traffic signboard out of the site area

- To carry out constructing the inner road so that it is not blood, enough strength in case

of executing in the rain season

- Constructing sewage system for site area, hygiene equipment, electricity, water servingfor shift of executive and workers

Preparation for execution equipment:

The list of the execution equipment serving for work as follows:

No Machinery & Equipment Capacity Quantity

01 DH62 diasel pile driving rig 50 –75 Ton 05

6

4 COMPLETION

07 Welding machine 300 – 1000 A 01

- If it is necessary to add the execution equipment to complete the pile driving work, thatwill be further mobilized

- All machinery and equipment, which have certificate of calibration, will be mobilized tosite However, mobilization of automatic pile driving will be priority

- The leading pipe system of pile driving will be checked before driving The slippingsystem must be insured in two directions

- Checking vibration degree of whole rigs and hammers in the during of pile driving, ifexceeding and not ensuring settlement while driving that must be repaired or replaced abigger one

- Pile lifting equipment, cable, puly, winch that must be checked carefully before using

- Welding machines must be checked carefully at points of joint especially input voltage

to ensure the safe of electricity and fire

- Surveying equipment must have certification of calibration of The Testing Center Staff organization:

- Construction teams must submit the list of qualification workers, supervisors working

on the site and site organization diagram to Supervising Consultant or Client for approval

- Also, they must submit the range of duties, rights and connected way for each personnelworking on the site

- The Contractor must submit the certificates of Supervisors, Welders, Crane Drivers andpile driving drivers, etc… to The Supervising Consultant or the Client for approval beforecommencing any works

PILE DRIVING WORK:

The order of pile driving:

Pile maintaining at site:

All storage piles at site keep in good condition carefully Be specific to comply withregulations as follows:

Piles comply with number of layers exactly (non exceeded 03 layers)

Supporters must be put in the correct handling positions marked on pile body Piles arenot put on the ground directly which maybe generate particular stresses to crack or breakpile to effect on quality of pile

Absolutely do not put any heavy objects on the pile body as well as preventing to hitbeside of pile body

Do not put piles which have the differ lengths together.

While transporting, loading to truck-trailer as well as unloading storage or installing intolocations, hooks and cables must be good; and when workers wear the cable into handlingpoints, they should be careful to prevent slipping and breaking

The previous fabrication piles should be driven first, the next pile will be driven laterunless having the other requirements from the Client or the Supervising Consultant Maintaining methods at site must be done strictly, any violations must be penalizedadequately to ensure the strictness and safety for all works

Surveying of pile location:

The work will be done immediately after completion of site plan preparation and havingfull of designed pile drawings They includes works as follows:

Locating standard level is obtained from the National standard level It should be doneand handed-over with Supervising Consultant and the Client because it will be base oncutting pile head after completion

Locating points of co-ordinate standard in piling location gridline

Locating points of pile is obtained from locations of points of co-ordinate standard

The surveying work are done by theodolites and checked in two perpendicular directions,also constructing fixed intermediate survey-marker to perhaps check promptly the co-ordinate system of pile driving

Pile driving:

Preparation works before driving pile:

Gathering full of pile quantity of adjacent driven pile positions Checking the number ofpile, diameter, length, pile location, hammer type, drop height of hammer to record onpile driven record sheet

Marking each 25cm for final piece of combination pile nos to determine the depth ofdriven pile

Preparation equipment use for recording pile set such as pile set recording form, drawingpencil and supporters etc…

If execution at area recorded to have obstructers, it should be removed out which is nearthe nature ground level or boring in advance if it is more deeper

Prepared dolly is soft wood such as fir or plywood with 5-10cm thickness The wooddolly is used one time for a driven pile only, it is not used for the next pile although itstill be in good status

Should use cover and dolly suitable with pile cross section The slits between pile hip toeach of the edge of cover should not exceed 1cm

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Pile driving execution:

Piles are installed in the rig and positions by chain-wheel crane or wheel crane withcapacity of 40-50 Ton or winch system of rig directly While handling, should payattention to points of wearing hook is necessary exactitude, especially dragging pile intothe rig at one point must be complied with Engineer’s instructions

Piles are checked the vertical degree in two perpendicular directions by theodolites and it

is careful continuously during driving procedure

Diesel hammer of 2.5 Ton is used to drive 0.30x0.30 square pile, 4.5 Ton, 6.0 Ton to

500 spun pile, 6.0 Ton, 6.5 Ton to 600 spun pile (when trial driving if stratum is soft,

it can be used the 4.5 Ton hammer to drive 600 spun pile)

When jointing pile, the joint is the welding joint, height and width welding is done asshown in design detailed pile drawing and welding rod is type of ELEPHANT KR-3000

On the other hand, alignment of under piece must be line to the upper piece and centricaxis of under piece is line to the upper piece

When driving, follow and check frequently as well as counting the blows of 100cmpenetration length to record in the pile driven record sheet

When driving to the final 3 meters, it has to count the number of blows of 25cmpenetration length When pile meets the required level, stop driving and record by mean

of pencil, supporter and paper of 10 blows continuously

To bearing pile, the ultimate bearing capacity of driven pile will confirm by Hiley’sformula to define the pile set, rebound and height of hammer

About 5-20 first piles, it is researched the pile set carefully to adjust the power’s hammerfor suitability and determine the penetration length of pile so that combination method ofpile is save and the execution time is shorten

In case of reaching the designed penetration depth but the pile set is not or contrary is tostop driving pile and inform to Surveying Consultant or The Client immediately to decidewhether continuously or not to prevent damaging pile body

To friction piles, driving pile will be stopped when pile tip reach the designed level orbearing capacity of pile is over the designed bearing capacity

While pile driving procedure, if any strange phenomenon are happened is to stop toinform to the Engineer to be instructed treatment method complied with 6.1-6.4 clausesbelow

Checking:

Checking before pile driving procedure: Checking slits on the pile body, bending degree,perpendicular degree to site plan

Checking certification of calibration of rig and pile driving equipment whether metallowable calibration criterions

Checking pile installation position suitable for design

While pile driving procedure, perpendicular of pile need to be checked frequently in twodirections as well as center of both of piece when jointing, especially appeareddeformations

Allowable tolerances:

The declination of pile position to drawing must be un-exceeded 75mm to the horizontal

of pile gridline and 75mm to the along of pile gridline

Axial direction deviation of pile that compares with axial direction of pile shown indrawing will not exceed 2%

Tolerances of installation will be specified as follows:

Form 1: Inspection and Test Plan

Form 2: Pile Driving Report

Form 3: Pile Driven Record

HANDING-OVER WORK:

Preliminary handing-over:

Piles transported to site will be checked preliminarily by means of tape ruler and visuality

to basic data as follows:

The length of pile: +50mm, -10mm

The width and quantity of cracks

Checking the clean pile body

Handing-over after pile driving:

The completion driven piles will be checked the bearing capacity of pile by Hiley’sformula as follows:

10

) (

* )

* 2

1 (

)

* (

*

*

Wp Wr c s

Wp n Wr H Wr ef Qu









Where:

Qu: The ultimate bearing capacity of pile (Ton)

ef: The efficiency of hammer, ef = 0.7 to diesel hammer

ef = 0.5 to drop hammerWr: The weight of ram (Ton)

H: The height of hammer (m)

Wp: The weight of pile (Ton)

s: Pile set (m)

c: Rebound of pile to a blow (m)

The general safety factor, FS = 3

Hiley’s formula will confirm the bearing capacity of working piles The actual bearingcapacity of piles will be re-tested by The static load test in accordance with VietnameseStandard TCXD 88:1982 “ Piles – Method for Site Testing” of Construction Ministry The result of driving piles shown as recording formatted forms, accepted piles whichapproved by Driving Contractor, Manufacturer, Supervising Consultant and the Client onthe above recording papers

Formatted forms:

Formatted forms of recording the pile set are attached in Appendix

Safety regulations on Site

SAFETY REGULATION ON SITE

5.1 The machine operators must be skill workers and have safety certification

5.2 Check the qualification of machine and major accessories: safety and precautionequipments, safety brake, bearing cable, … to ensure the common abilities of workingwithout breaking down Any unusual signals should be repaired before operation

5.3 Maintain coordination closely during fastening and pulling piles to minimizecomplications

5.4 Forbid lifting pile while the fixation is not tight

5.5 Forbid lifting pile while it is covering by other object or being underground

5.6 Forbid lifting pile during moving or turning the hammer

5.7 Forbid lifting or lowering over speed

5.8 Forbid releasing bearing cable before pile getting steady position

5.9 Not allow operators to move the pile which carrying worker over

5.10 Not allow operators to move piles overhead

5.11 Not allow operators to leave the pile in suspended situation during temporarystopping.

5.12 Forbid to carry out in strong wind weather

5.13 Forbid to carry out in dim light, foggy or lack of light

Pile reached at the designed depth before reaching the required pile set: in this case, itshould be to inform to Supervising Consultant or the Client immediately to considertreatment methods or connect the second pile to drive the pile until reaching the requiredpile set or stopping to drive to cancel it and adding the other

Pile is broken at the pile head in driving: if happened, it should be to inform toSupervising Consultant or the Client and Manufacturer to consider the grade of destroyedpile head together

If the pile head is damage slightly such as appearing the slits around the hook or peelingoff concrete outside the pile head, it is done to cut off damage part of 0.3-0.5m from theend of slits, then pasted the end plate other by Epoxy glue and it is driven continuouslyafter 30 minutes

If the pile head is damaged strictly such as collapsing on side or the length of breakingcompletion concrete to expose reinforcements are large, at that time, it should beapproved by Supervising Consultant or the Client to permit to treat as the above or addthe pile other

Pile is driven over the above allowable tolerances in 3.2 clause: adding the pile other orenlarging the pile cap if Supervising Consultant or the Client approved

3 earth works

* Sequence and method of excavation works:

- The Contractor will receive and protect established benchmarks in the manner approved

by the Engineer Grading work will be carried out to the line and levels shown on thedrawings

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- Use excavator machine for excavation approximately to the design level, combiningwith the workers trimming Special care should be taken during excavating near the RCpile.

- Obstacles, voids and excess excavation will be treated in the way indicated in thespecification and executed under prior approval of the Engineer Commonly excessexcavation will be fill with lean concrete or selected hard aggregates

* Access planning and traffic movement in and around the site:

- Appoint signal persons for regulating traffic of dump trucks transporting surplus soil andmud out of the site

- Maintain access road in a good condition during earthwork

* The de-watering system, discharge point:

- Excavation will be kept free from water at all times, contract sumps with suitable sizeand keep the water table below the bottom level of foundation by using of water pumpwith big capacity A team shall be appointed specially in charge of maintaining dischargewater system on site This team will consist of pump operators and labors The team willstay 24 hour per day in the rainy days for immediately action

* Disposal and store of excavated material:

- Truck for transportation of soil should be covered with sheet

- Backfill simultaneously on each side of the foundation, protect the waterproofing workunder strict supervision of the Engineer

- Compact sand by layer being less than 30 cm by hand or hand rammer, care will betaken during compaction to avoid fracture or harm to the underground structures andpiping works

- Check the foundation elevation by the leveling machine, do preparation for leanconcrete

4 form work