01 MS for manhole

The crane operator will then be instructed to hoist lifting tackle clear of any obstructions and position the crane ready for the first required lift.. • Step 3: Lifting precast manhole

METHOD STATEMENT FOR EARTHWORK AND

CONCRETE WORK OF MANHOLES

(DOCUMENT CLASS: X)

Operation Centre JOB Code: Operation Centre Doc No.:

1 INTRODUCTION 3

2 SCOPE OF WORK 3

3 REFERENCES 3

4 ORGANIZATION CHART - RESPONSIBILITIES 5

5 EQUIPMENT 6

6 MATERIALS 6

7 RESOURCES 6

8 PROCEDURE 8

9 SAFETY 10

10 TRAFFIC MANAGEMENT PLAN 15

11 WASTE MANAGEMENT PLAN 15

12 APPENDIX #1 25

13 APPENDIX #2……… 42

3 REFERENCES

Earth Work Specification: 3550-8310-SP-0009

Specification for Concrete works: 3550-8310-SP-0005

Construction Specification for Concrete Work: S-000-1320-1001V

Scaffold Procedure: S-000-1654-0400V

Specification for The Foundation of Storage Tanks: 3550-8310-SP-f0006

HSSE Instructions to Sub-JGCSs: S-000-1654-0250V

Safety Transportation Management Plan: S-000-1654-0300V

HSE Instruction to JGCSs: 3550-8710-SP-0003

Drawing for construction issued from JGCS

Vinaconex E&C HSSE Management Plan VV3120-008-A-403

Vinaconex E&C Traffic Management Plan VV3120-008-A-406

Vinaconex E&C Waste Management Plan VV3120-008-A-404

Vinaconex E&C Emergency Response Plan VV3120-008-A-402

Construction Drawings for Manholes

Construction drawing for Pipes

Drainage Materials and workmanship 3550-8310-SP-0011

Standard pipe connections to manholes D-000-1316-1003V

4 ORGANIZATION CHART - RESPONSIBILITIES

Site Manager: Do Minh Chau

Directly in charge for daily schedule, mobilization of equipment, materials supply capacity.

Survey, daily schedule, location of work, equipment control, labor for each kind of works

HSSE

HSSE Manager: PN GiangHSSE Supervisor: LH Trung,

VN Hai,HD Bach, DT Ninh

Equipment HSSE control, Permit, access way, Traffic, Labor entry, HSSE training, HSSE at work place

- Labors for works

- Minor tool and equipment, sub- materials, form and

Const Equipment

Condition and number

of Equipment, fuels, drivers, transportation, traffic control, signal, service.

5 EQUIPMENT

Equipment Name, Capacity No

s

Year of Manuf.

Origin

2012-2014

China

16 Automatic Leveling machine:

NIKON

- Prior to using any machineries/equipment at site, it will be inspected and certified by

qualified person

- Periodic Preventive Maintenance will be made by all equipments and machineries

- All operators and drivers are to be educated with valid driver’s license/operator’s license or permit from concerned government agency

- Only authorized drivers and operators are allowed to operate equipment and machinery

- Only authorized signalman will be assigned together with the driver or operator

Sub Concrete: mainly from batching plant of VINACONEX E&C installed on site (batching plant

of Viet Han, SAKURA, VIMECO, OIC or other approved ones by JGCS are standby option)

- Reinforcement: Shall be transported to workshop in the site (submitted to JGCS forapproval)

- Non shrinkage: Shall be submitted by JGCS

- Prior to working any work at site, all workers will be trained safety and certified by JGCS’HSE

- All workers must to have name card for travel on the site

- There are 2 teams for this task

Team 1 working at C200

Table 7.1: LIST OF MANPOWER FOR TEAM 1

1 Driver of excavator 1 2

Table 7.1: LIST OF MANPOWER FOR TEAM 2

10 General workers 6

Notes:

- Labour mobilisation schedule would be revised based on updated plan

- VINACONEX E&C will assign HSSE Supervisor and First Aiders regarding worker ratio, 1per 50 workers

- Management staff (see paragraph 4)

24.1 Process for Manhole construction (For manhole with depth of less than 2500mm – Precast

concrete):

 Fabrication rebar, formwork and concrete work on the Fabrication yard (on the ground level)

 Preparation fabrication yard

 Concrete work

 Curing of concrete

 Excavate manholes located

(If slope higher than 1:0.5 use polythene sheet and sand bag)

 Instalation crush stone level thick 20-25cm (if soil condition is very wet and soft make the temporary trench)

 Casting lean concrete to design level

24.2 Transportation and erection

24.2.1 General requirements

• Site checks before operating

Hard barricade and signage shall be set up around working area

Check for the safe entry and exit of the crane from the site

Check ground condition

Check where the crane is to be position to pick up, swing and deposit the load

Check all lifting gear to be used

Check whether site personnel have been informed as to the dangers of working in the vicinity

of any moving precast manhole and the crane

Check for power lines and correct distance for operation of crane

Check for location of overhead service lines (e.g Steam pipes) to ensure clear operation ofthe crane

Check for location of other facilities which may impact the lift

Check surrounding structures, including making allowance for rear end swing

Check for any obstructions

Ensure that the operating radius is clear of passageways and any pedestrian area, and if not,ensure adequate traffic controlling measures are put in place

Check for underground services, pipes, gas mains and tunnels or any weakness in the surfacewhich will not sustain the combined weight of the crane, the load and any gear to beemployed in the lifting process

Check for recently filled trenches

The correct weight of the load must be obtained by the operator prior to the lift This may be done

by weighbridge certificate, by engineer's certificate, or correct calculation by a competent person.The weight of the precast MH, CB and the gear must be checked with the relevant load chart toensure safe operation at all operating radius

The lifting are should be checked to ensure sufficient clearance if the load should drift

The position of the crane for lifting to ensure that sufficient area is provided for outriggers or

stabilisers to be fully extended and packed.

The size of the load must be combined with the height to be lifted and the radius to ensure that theload will not become "boom-proud"

• The safe use of th e crane:

The crane should not be used during inclement weather, if such weather would make safe useimpossible

The wind must be taken into consideration to ensure that the load can be adequately controlled, andbulky loads, such as too much or too large precast MH, CB will not overload or overturn the cranebecause of wind pressure

The precast manhole must be kept as near to the ground as possible at all times

Traffic control plans will be put into place to ensure safe operation in traffic, and ensure that theprecast manhole is not lifted over or near pedestrians, traffic or neighbours property

If necessary, the work area will be cordoned off, especially the area of rear end swing

The crane will be kept level at all times when lifting precast MH and CB to ensure that side- pullwill not occur

Sufficient turns of wire on hook will be used to ensure that the load is properly supported inaccordance with the load charts and crane specification

If moving the crane while with holding the load is required, the load will be secured to the craneand a spotter used to make sure the operator is aware of all hazards

If boom extension is needed, then the correct sequence of boom extension must be used

The crane operator must not leave the crane driving station while the crane is under load

The crane will, at all times, be operated in accordance with manufacturer's specification

Fly jib installation, if required, will only be carried out by qualified, experienced personnel, anderected in accordance with manufacturer's specification, and correctly stowed at the end of the jobfor travel

Check the lifting gear carefully before using it in the lift, and such gear must be used within theirrated Safe Working Load rating, and in accordance with their design

• Dismantling:

When lifting operations are finished, the operator will leave the hooks clear of all obstructions

The boom will be retracted and lowered in a safe manner, ensuring that the hook block(s) are raised

in conjunction to ensure that the hooks do not foul any object

When outriggers are out of sight, the supervisor will ensure that a lookout or observer will keeppeople away when

retracting the outriggers

Oncethecraneissecure

Methodology of transportation, loading, unloading and installation

The following Chart describes the lifting work sequence:

• Step 1 Preparation for work

The crane, together with the associated operating crew will arrive on site at the specified

and agreed date and time

At the beginning of each day starts, tool box meeting is required to inform all people about

the activity shall be conducted

Guide all workers for safety rule must be followed during lifting activity

Assign barricade, guide line and signage in the necessary location to inform people about

dangers may happen

Any traffic management, ancillary pans, maps or temporary roadways etc are required to

be positioned or other means, prior to the crane or cranes manoeuvring into position, it will

be done under the instruction of the Supervisor

Preparation for works

Installation lifting devices

Lifting MH to the trailer

Transportation of MH

Unloading MH

Finish the work

• Step 2: Installation lifting devices

Upon completion of the rigging procedure, the crane operator will carryout procedural

safety and checks again, implementing any specific operational requirements

The crane operator will then be instructed to hoist lifting tackle clear of any obstructions

and position the crane ready for the first required lift Any deliveiy/removal vehicles will

now be positioned adjacent to the crane as right position, ready for work to commence

Depending on the load of precast manhole (in this case the maximum load is the manhole

which have load around 10 ton], we can choose the cable for lifting It shall be check and

agree by supervisors and safety officer prior conducting work

• Step 3: Lifting precast manhole to the trailer

Flagman will issue instructions via hand signals or two-way radios to the crane operator to

position the crane over first required lift, flagman will plumb the boom head, directly over

the load or set short to allow for jib deflection where necessary

The flagman will instruct crane operator, the lower the hooks with lifting tackle to allow

trained rigger to attach lifting tackle to load

Once the load is clear of all obstructions, the flagman will give instructions to the crane

operator to manoeuvre the Precast manhole the right position on the trailer

The flagman will instruct the crane operator to lower the load to just above the landing

position and then instruct the operator to stop lowering, after that site supervisor will

confirm position and orientation of load prior to landing

Once the lifting tackle is clear of all obstructions the flagman will instruct the crane

operator to manoeuvre the crane ready for any further lifts that may be required and had

over to another flagman were required

• Step 4: Transport by trailer

The supervisor shall check again to make sure all precast MH and CB are in right position

and stable on the trailer Avoiding statement that precast MH, CB can be moved while

transporting it

Use chain to fix precast MH, CB on the trailer

The driver must have right certification and good experience for driving the trailer

Safety check for road travel must be carried out before transporting If there's any obstruct

object, remove it and make the ways always clean from dangers

• Step 5: Unloading the precast manhole

The Supervisor will then instruct the crane operator to lower all lifting tackle to the ground to

allow removal from hook.

The crane operator will then instigate the removal of any lifting tackle stored on the crane andthen commence the de-rig procedure

All personnel assisting with de-rigging will be under the guidance of the crane operator at alltimes The de-rig procedure will be carried out as per crane manufacturers manual

The remaining members of the lifting crew will ensure that any ancillary mats or equipmentetc.are removed from site or placed in an appropriate position ready for collection prior tothem leaving site

The supervisor will inform the Site Manager or site representative of the completion of theoperation and address any issues that may be raised and inform of any equipment left on sitefor later collection

24.2.2 Transportation to erection site

Precast manhole will be transported from the storage yard to the erection site by trailers.Precast manhole will be fixed properly during transportation

Worker will be control the precast mahole by tag line

Install temporary bearing with wedge

During lifting and unloading arrange some worker to control the precast manhole to locatedposition as design,put it down slowly and carefully

Surveyor will be check final correct position and level for each precast manhole

After install Manhole, Lifting hook will be cut and put motar (motar shall not be less than the

compress strength of panent concrete) in hole

8.2 Process for Manhole construction (For manhole with depth greater than 2500mm – In-situ concrete):

Removal of formwork

Installation ofMiscellaneousSteels

THE SEQUENCE FOR EXECUTION OF MANHOLES

-Using excavator excavating to design level

(If slope is higher than 1:0.5 use sand bag and plastic sheet to protect the slope)

b) Blinding concrete works

-Reinforced concrete foundation shall be placed upon blinding concrete whose strength classshall be C16/20, not less than 50mm thick, and laid over the ground immediately after

excavation to provide a clean working surface Blinding concrete shall not be laid until existingground to receive blinding has been approved by the JGCS.

-Under yard paving, 0.25mm thick heavy duty polythene sheet may be used instead of concreteblinding Polythene sheet shall be laid in the longest lengths and widest widths available withoverlaps not less than 150mm at all joints and intersections Polythene sheet shall be laid on asurface free of hard spots or projections likely to cause a puncture

c) Rebar works

Fabrication of Reinforcement:

- All Steel reinforcement shall be deformed, high yield and shall have a minimum characteristicyield strength of 460 MPa complying with BS 4449 grade 460 type 2 or ASTM A615 grade 60(fy=420 MPa) and approved by JGCS for types and brand names (paragraph 3.7 ConstructionSpecification for Concrete Work: S-000-1320-1001V)

- After delivery reinforcement on site, inspection will be conducted by delivery slip, the certificateand checking invoice until conforming to the specifications Reinforcement will be laid on themanholes Cover sheet will be used for preventing from rust

Cover sheet

Storage of reinforcing bar s

- After cutting and bending the reinforcing bar, shapes, numbers and bending radius will bechecked for conforming to the drawings and specifications Reinforcing bar shall be cut according

to mechanical method and bended follows requirements of the drawings and specifications.(paragraph 14 Construction Specification for Concrete Work: S-000-1320-1001V)

- Reinforcement which has been bent to facilitate transportation in short trucks shall not be used

Installation of reinforcing bar:

- Using concrete spacers to keep specified concrete cover for reinforcing bar The spacers aremade of precast concrete blocks having a compressive strength not less than that of theStructure concrete

- Area for storage of reinforcing bar shall be covered to be avoided from dust, raining water in

case casting concrete has not been started

DETAILS OF ANGLE BAR , ANCHOR

-Formwork is made of steel or plywood with steel frame

- Store for form and scaffold shall be covered and form condition should be regularly maintainedafter each time of using

- When the formwork have been checked and accepted, using separation materials for formwork

to prevent adhesion between concrete and formwork, in addition, this shall make easydisassembly, flatness, evenness for structures

- Form tie of steel rod will be applied at two level, the hole remained after removing of form tie will

be filled with cement mortar

Concrete mixing at batching plant and transportation:

- The batching plant will be ready for supply at the time of placing concrete

- Accurately scaling and measurement of concrete is required for concrete mixing Water andhumidity of sand and aggregate should be regularly checked and adjusted in order to get theslump as required

- Transporting concrete from batching plant to casting location by concrete mixer trucks Based

on concrete volume casted for each item and casting speed as well, JGCS shall arrange number

of concrete mixer trucks as required assuring the concrete’s uniformity and slump specified in theproject technical specification

- Water must not be added to the mix after the concrete has left the mixer

Casting and Compacting Concrete:

- Concrete will be cast with concrete pump truck

- The vibrators will be inserted into concrete vertically The intervals of the insertion of vibratorsare constant and suitable space in consideration of effective area of the vibration It is prohibited

to contact vibrators with reinforcing bar and move concrete by vibration Vibrators (needlevibrator) shall be inserted at such distances apart or applied in such a manner as will ensure thatthe concrete is satisfactorily and uniformly compacted Immersion vibrators shall penetrate thefull depth of the layer, and shall be withdrawn slowly to prevent the formation of voids When theunderlying layer is of fresh concrete, they shall enter and re-vibrate that layer to ensure thatsuccessive layers merge together Vibration shall be carried out in a manner which does notpromote segregation of the concrete Immersion vibrators shall be withdrawn slowly to preventthe formation of voids

- Compaction shall take place within 30 minutes from the time when agitation of the mix hasceased When ready mixed concrete is supplied in purpose-made agitators the time between theintroduction of cement to the mix and compaction shall not exceed 2 hours and shall not exceed

1 hour when air temperature exceeds 25°C (paragraph 9.2 of the Construction Specification forConcrete Work: S-000-1320-1001V)

- During concrete casting, it is required to regularly check and observe formwork and seal anyleakage, if any

- Concrete shall be placed in layers that are approximately horizontal and not exceeding 450mm

in depth

- The cover seat will be prepared for preventing rain during concrete casting

- Fabrication of test cylinders and transportation to the laboratory shall be the responsibility ofsub-JGCS The rate of sampling for strength testing shall be one per 50 m3 of concrete Theminimum number of test cylinders to be prepared from each sample shall be six, three for testing

at age 7 days and three at 28 days

e) Finishing and curing works

Finishing and Curing Concrete:

- After concrete progresses hardening, concrete surface shall be finished by steel trowels so thatcoarse aggregates do not appear in the concrete surface

- Curing shall be carried out in anncodance with the requirement of BS 8110 Immediately afterfinishing or removal of formwork, the exposed surface of the concrete shall be protected duringhardening from the effects of sun, drying winds, cold, rain or running water Until after the initialset of the concrete the means of protection used shall not be supported from the concrete.During curing the concrete shall be protected from damage by shock, vibration, water, frost, orany agent likely to interfere with the process of setting and hardening Loads of any kind shall not

be placed on the concrete during the curing period without permission from EMPLOYER/JGCS

Removal Formwork of Structure:

- Vertical formwork shall be removed after 01 day Removal works shall be carefully carried out

so that no damage or defect occurred to the structure

- After removal, formwork shall be cleaned and maintained at site workshop

f) Connect pipes works

DETAILS OF CONNECTION GRP PIPES

DETAILS OF CONNECTION RCP PIPES

DETAILS OF BOX OUTS FOR PUDDLE FLANGE

BOX-OUT SIZE FOR RCP AS FOLLOW:

BOX-OUT AND PUDDLE FLANGE SIZE FOR GRP AS FOLLOW:

g) Backfilling works

Backfilling by excavated soil after casting of concrete of manholes

Using of roller and Rammer for compaction (less then 5T) in adjacent area to newly castedmanholes will be carried out minimum after 3 days or when the compressive strength of concretegain more than 70% of the design compressive strength Backfilling by layer less than 300mmun-compacted thickness

Construction tolerance for in-situ construction and placement to complied with paragraph 16 of

the Construction Specification for Concrete Work: S-000-1320-1001V

1.1 Manholes

Each manhole shall be tested for watertightness in the presence of the Engineer by filling with