METHOD STATEMENT FOR CONSTRUCTION OF CW INTAKE PUMP STATION

The purpose of this method is to describe the methodology involved in construction work for the CW Intake Pump station item and to detail out the steps to be taken in order to meet the technical requirements of VP1 BOT Thermal Power Plant

PREFACE

The purpose of this method is to describe the methodology involved in construction work for the

CW Intake Pump station 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 1 BOT Thermal Power Plant

 Company/Owner Van Phong Power company limited (VPCL)

 ITEM CW Intake Pump station

MANPOWER & EQUIPMENT

• Manpower mobilized for construction of the Boiler are listed as followings:

• Equipment mobilized for construction of the Boiler are listed as followings:

No Equipment Unit Quantity Remark

VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

RESPONSIBILITIES AND ORGANIZATION

• It is overall responsibility of Site Manager to organize resources prior to perform construction activities as per project specification in compliance with the quality, schedule & safety requirements

• EHS Manager will ensure in coordination with Site Engineer that all measure/construction taken shall be maintained till completion of job

• It is the responsibility of Construction Manager/Site Engineer that construction activities are executed according to the relevant project specification in compliance with the quality, schedule & safety requirements

• Contractor will ensure that all works are performed safely according to the attachment

• The relevant Contractor Supervisor will ensure that the work is carried out in accordance with this method statement and project specification

• The QC Inspector will ensure that the work is executed according to the requirements of quality dossier are fulfilled

EHS Safety Supervisor DHI-Civil Site Engineer

CONSTRUCTION WORK

Excavation

Dry soil will be utilized for backfilling on-site, while wet soil will be designated for filling in the landfill area Additionally, mud will be transported to the designated disposal area.

• Before start excavate work, Dike, hard barricade system at EL: +5.6 surround pit shall be made.

• The clearance between the edge of foundation to bottom of slope (1.5m) will be complied with the submitted drawing

• The calculation for drainage of pump will be attached as an attachment

• The state of slope should be checked for stable before install ladder and during working time.

Reinforcement work

Steel bars should be stored on-site using racks or supports that elevate them above the ground to prevent contact with moisture Additionally, covering the bars with plastic sheets is essential to protect them from corrosion caused by the marine environment.

• Bar bending schedule shall be submitted before commencement of work

• Fabricating, installing foundation rebar comply with the approved design, project specification, ACI

117 and ACI 318, approved BBS Lap splicing method shall be used for rebar connection, the lap length shall comply with the approved design drawing and applied standard

• Any kind of hot cutting and bending rebar shall not be allowed

• Fabricated rebar will be transported from the workshop to construction site by lorry crane

• Rebar shall be erected such as to form a rigid cage within the formwork, with every intersection being bound together with appropriate binding wire

Rebar chairs with the specified diameter and spacing must be installed between layers of reinforcement to ensure proper positioning A detailed calculation of the rebar chairs will be submitted for review and approval.

• Specified concrete cover shall be maintained using precast concrete spacer blocks of the same grade as the concrete in which they are to be used

For securing reinforcing bars, 1mm thick black annealed steel binding wire will be utilized, with the wire being double folded to guarantee a strong and reliable connection.

• Concrete spacer shall be made by same grade concrete as structural grade

• In practicable, the subcontractor could use extra method such as steel tube frame, cables, turnbuckles… to keep the rebar stable before carrying out the next steps

• Inspection of rebar installation shall be conformed to design drawing and approved method statement, such as grid space, lap length, elevation…

Installation of Embedded plate, box out, cable entry ducts (If any)

• Inserts are fixed in a position in accordance with the drawings and checked for its line and level

The Site Engineer meticulously verifies the positioning and levels of embedded plates, box outs, and cable entry ducts before welding the inserts to the reinforcement, ensuring stability during concreting To prevent any lateral or vertical movement, adequate supports are provided for the inserts, and it is crucial to ensure that no shuttering props come into direct contact with them.

Regarding CW pipe, after finishing the pipe installation as the detail by the LOT3 and handover to LOT4, installation of rebar, formwork and cast concrete will be proceeded

Installation of cable entry ducts

Form work

Forms must be constructed from steel or durable waterproof plywood, ensuring they adhere to the specified shapes, lines, and dimensions outlined in the drawings These forms should be robust, rigid, and unyielding to maintain structural integrity.

Forms must be carefully designed and securely supported to prevent any deflection or bulging during the concrete placement and compaction process They should be tightly constructed to ensure that no mortar is lost.

• Forms for successive lifts on adjacent parts of the structure shall be so arranged that a continuous, uniform and harmonious texture of concrete surface results

• Fabricated forms will be erected on 3 sides and adequately supported using steel props and bolts/clamps

• The vertically, line and levels of the erected forms shall be checked by the formworks Foreman first instance and subsequently by the Site Engineer and Surveyor

• The last side of forms will be erected after the completion on fixing of all inserts and cleaning

• Formwork shall be strong enough to withstand, without distortion, all pressures resulting from placing and vibration of concrete and shall be rigidly and accurately fixed in position

• Formwork shall be securely fastened to prevent loss of mortar and surfaces in contact with concrete shall be uniformly smooth and true with no local defects

The Intake Pump Station's formwork features a combination of steel and plywood, thoughtfully designed to accommodate rebar placement and ensure safe access during both assembly and dismantling Standing at a height of 3 meters, this formwork system enhances operational efficiency and safety.

• The capacity of form and frame system are calculated following the attachments

The formwork will be constructed panel by panel and lifted into place using a crane Each panel is interconnected with tie rods and bolts, ensuring stability, while a supporting and cable system maintains their vertical alignment.

• Tolerance: ±6mm for dimension, ±12mm per 1.5m length

Concrete work

• Reference Method statement: “VP1-0-L4-C-GEN-10007_ Method statement for General concrete work” for requirement and describe of concrete work

The foundation's subgrade must be thoroughly compacted to ensure the quality of the lean concrete, except when the surface is rock, which should be cleaned Additionally, any marshy areas must be removed and replaced with suitable material to achieve proper compaction.

• Lean concrete thickness will be complied with the design drawing After cast concrete, curing time is required to get enough strength of concrete before carry out the next activities

• Base slab shall be pouring concrete with one time The calculation of concrete supply will be depicting into an attachment

• Plan of Formwork for base slab

• Typical of formwork panel Space of pipe support, tie rod is 800mm

• Wall shall be pouring concrete with 5 times, maximum height is 3m

• Contractor will prioritize the execute for outside wall first After casting concrete of two phase for outside wall and inside wall will be followed

• Typical of formwork panel Space of tie rod is 800mm

Following the completion of the third stage of wall casting at elevation -0.75m, backfill the soil to elevation -0.70m Subsequently, proceed with the installation of rebar, formwork, and concrete casting for the mid slab, followed by the curing process.

• Slab shall be pouring concrete one time used scaffolding system as allow: The volume of concrete is around 788m3

The installation of a scaffolding system and platforms around the Intake Pump Station is essential for safe and efficient wall execution, with the height of the scaffolding varying according to each stage of the project Platforms are spaced 2 meters apart, providing ample room for workers to move and utilize the lower platform as a base for constructing the next one, thereby enhancing safety To comply with Doosan's safety standards, the working platforms are equipped with handrails on both sides and ladders for secure access between levels Prior to the installation of rebar and forms, the scaffolding and platforms will be thoroughly inspected by a scaffolding supervisor to ensure compliance with safety regulations.

 Calculation of support will be attached as an attachment to review and get approval

• Execution plan of horizontal construction joint

• Installation water stop bar W250 at construction joint location as follow:

• Concrete slump, temperature shall conform to approved mix design

• Sampling from trucks shall be advised by the Engineer/As per Site Inspection and Test Plan

• Casting time shall be informed to related party before at least three days for preparation work

• In case of hot weather, the nighttime for pouring is prioritize Cooling the aggregate and mixing water if necessary

• In case of sudden rain, plastic sheet will be used to cover the top surface

• If it rains during concrete pouring, Contractor will cover by plastic to ensure continue construction

Contractors will sew together plastic sheets large enough to fully cover the base slab, ensuring complete protection Additionally, a backup plastic cover will be kept on standby near the concreting area for added security during the project.

• Besides, the water pump will be arranged to pump water from inside to outside of working area

Concrete placement will be executed using a pump, with a flexible hose securely clamped at the pump's end This hose will be positioned within the pouring area to regulate the concrete pouring height The contractor will devise a plan for the hose's location, ensuring it passes through the top rebar layer Concrete will be poured in horizontal layers of 400mm until the desired height is achieved A smooth discharge of concrete will be maintained through effective coordination between the person operating the vibrator and the one discharging the concrete.

• Concrete should not be dumped in several locations at a time nor discharged in large hips and moved horizontally until final position

• The concrete casting shall be performed layer by layer, preventing the formation of cold joints The layers shall be separated with heights not greater than 2/3 of the vibrator length

6.5.7 Curing and Temperature Control for Mass concrete (bottom slab only)

• Control the temperature of the concrete when it is placed not to exceed 30 degrees Centigrade

• Cooling the mixing water with water chiller plant

• Cooling the aggregate by shading or spraying water prior to concrete mixing

• Mass concrete center temperature shall not exceed 70℃ and must be less than 50℃ per meter, difference of temperature in center and surface of the concrete not exceed 20℃

• Water shall be continuously introduced on the saturated burlaps in order to keep the burlaps being wet at all time during curing period

To ensure optimal curing of concrete, it is essential to cover the entire surface with burlap or plastic sheets about one hour after pouring Continuous watering of the saturated burlap is necessary to maintain moisture throughout the curing period.

• The measurement purposes are to find the temperature development within the concrete mass The results will show peak temperature and the temperature differential for such measuring points

A thermocouple is a sensor installed within concrete to monitor its internal temperature This monitoring process occurs every two hours, both day and night, ensuring accurate temperature readings during the curing of casted concrete.

Thermocouples will be strategically embedded within the concrete structure, with top and bottom sets positioned approximately 300mm from the edges These devices will convert the heat generated into electrical signals, which will be transmitted to a digital thermometer for accurate temperature recording The maximum temperature of the concrete is expected to occur 3-4 days after placement, gradually decreasing to match the surrounding air temperature by day seven.

• The process of monitoring of temperature will follow below:

Following the completion of casting, the Automatic Recorder initiates temperature measurements every 2 hours for the first 48 hours, then shifts to every 6 hours until reaching 120 hours After 120 hours, the measurement frequency changes to once per day until the peak temperature drops to 45°C, with the temperature difference falling below 20°C and the gradient being effectively controlled.

Table to record temperature inside mass concrete

To address a temperature difference exceeding 20℃ between the center and surface of concrete, it is essential to implement an immediate method statement This involves covering the top surface with a 3cm thick foam and maintaining the side formwork until the temperature differential is controlled Additionally, water curing should be continued for a minimum of 7 days following the concrete pour to ensure optimal results.

Side formwork should be removed 3-4 days after concrete pouring or when the temperature difference between the center and surface of the concrete does not exceed 20℃ During the required curing period of 7 days, the exposed concrete surfaces must be kept completely covered with a plastic sheet or burlap to maintain continuous moisture.

Backfilling work

Filling work will begin only after receiving approval from the Engineer-in-charge and after the finish surface concrete and protective coating are approved A separate submission will be made detailing the method for repairing the concrete surface and applying Bituminous Waterproofing.

Approved excavated material from the site can be utilized for backfilling, while poor-quality excavated material should be replaced with fill from approved borrow pits or other compliant sources that meet the necessary specifications.

Backfill material must be approved by the Engineer and should be free from roots, stones, and debris It is essential to inspect for large stones or any other objects that may remain in the trench after the concrete has been poured.

To ensure a stable foundation, the material must be evenly distributed in uniform horizontal layers across the entire area, avoiding segregation Each layer's thickness should not exceed 30 cm after compaction.

• Care must be exercised to protect, pipes, joints and other features from damage due to backfilling and consolidation

• The type, size and efficiency of compaction equipment shall be capable of achieving the specified degree of compaction Use plate vibration, rammer, roller, bulldozer for compaction

• Field density test (FDT), Material backfill shall be carried out according with ITP General Excavation and Backfilling work The compaction density is K

• During backfilling work, GWL should be monitored, if it is higher, the dewatering must be applied.

INSPECTION AND TESTING

The Site Inspection and Test Plan (ITP) will be executed in accordance with the ITP for General Excavation and Backfilling work, ensuring that all concrete work adheres to the ITP guidelines for General Concrete Work.

ENVIRONMENT, HEALTH AND SAFETY (EHS)

Risk assessment and Job Safety Analysis

Project: Van Phong 1 BOT Thermal Power Plant Project Assessor(s):

Activity General Concrete work - Formwork fabricate and install - Assessment Purpose

Pouring concrete - Curing Preparation for Method Statement of

Job / Task People Cause of

Assessment at Risk Adverse Effect

1- Mobilization of manpower and materials, equipment

Site personnel /Public /Subcontra ctors

- Unauthorized vehicles and pedestrians passing through site entrances

- Lack of suitable access/egress from the project location

- Lack of awareness and suitable control measures implemented

- No control of delivery vehicles (& drivers) travelling to, from or around site

- Competent persons must be choose with suitable and talent, skill for job Their full legally documents with certificates, license must be checked and submitted Full PPE required

- Gate Entry: only authorized persons to enter site with the relevant ID card and site pass for vehicle

Both documents shall be given to personnel who have undertaken an EHS induction training

- All suitable access/egress locations, signage, pedestrian walkways and routes will be highlighted on the traffic management plan and site layout plan

- Suitable speed limits will be enforced for jobsite and public road

- Adequate warning signage will be erected on all routes

- Good visibility allowed for vehicles entering/exiting site and the public passing-by

- Entrance well maintained; kept clean, level and trip free

Control measures will be regularly reviewed and monitored to assess their suitability and improvements made if required

Any modifications to working conditions or operations, such as changes in sequencing, the introduction of new plant or equipment, or the involvement of new workers, will necessitate a new risk assessment This assessment will lead to the implementation of additional control measures tailored to the specific operation.

- Effect on people health from hazardous fumes

- Provision of Mobil toilet at site

- Provide waste bin at site with instruction and rules

All delivery vehicles (& drivers) travelling to, from or around site/

- Collision with vehicles and pedestrians due to lack of knowledge and awareness of traffic routes

- Not wearing the appropriate PPE when on site

- Bad vehicle technical quality status

- Overturning of vehicle when unloading

- Vehicle and equipment must have full legal document as Requirements and must be inspection before allowing to enter the site

- Any material enter to site must be declared and inform to the Consortium to be approved before enter the site

- Traffic management plan and site layout shall be produced and displayed at site entrance

- All suitable access/egress locations, signage, pedestrian walkways and routes will be highlighted on the traffic management plan and site layout plan

- All delivery drivers to receive brief induction & direction from gate attendant

- Delivery vehicles to be escorted by trained banks man at all times

- All delivery drivers to wear min PPE inclusive of safety helmet, safety shoes, safety glasses and high-visibility vest

- Traffic controllers assigned on intersections and congested areas

- Only certified and qualified riggers will load / unload materials during lifting operations

Any modifications to working conditions or operations, such as changes in sequencing, the introduction of new plant or equipment, or the involvement of new workers, will necessitate a new risk assessment This assessment will ensure that appropriate control measures are implemented to align with the updated operations.

Health ]- Use of public roads- Dust emissions into the air- Generation of noise- Soil contamination from vehicle/plant and equipment

Noise and dust pollution significantly impact public health, leading to respiratory issues and other health concerns Additionally, ground contamination arises from oil spills or leaks from plants, equipment, and vehicles, posing serious environmental risks Traffic congestion on public roads exacerbates these problems, affecting local road conditions and increasing stress for residents and nearby buildings Overall, the combined effects of noise, dust, and contamination underscore the urgent need for effective management strategies to protect public health and the environment.

To effectively manage the environmental impact of the project, we prioritize traffic control during peak hours on public roads and implement regular water spraying on roads to minimize dust All vehicles and equipment undergo thorough inspections before site entry to prevent oil spills or leaks Additionally, vehicles transporting bulk materials are covered to prevent dust dispersal during transit, both on-site and off-site We also monitor noise levels from plant and equipment, restricting high-noise machinery from entering the site To further reduce dust dispersion, we regularly spray water on stripped topsoil, and our secondary containment systems are designed to hold at least 110% of the container's storage capacity.

- Dust emissions into the air

- Use of hazardous substances and soil contamination

- Effect on public health due to dust and noise

- Effect on public health due to uncontrolled use of hazardous substances

- Control of noise by selecting efficient equipment

- Control of dust through regular water spray on roads

- Equipment inspection before entering to site to check any possible oil leakage

Site personnel /Public /Subcontra ctors

- Overturning and overloading of vehicles

- Lack of signage and speed limits

- Lack of barriers along roadways

- Lack of training and awareness

- Lack of designated parking areas

- Entering heavy equipment operated range/ high-risk activities operating

- Traffic management plan; informed during training and displayed on site entrance

- Only travel or driving at suitable and sufficient traffic routes (vehicle and pedestrian segregation) or through the access / egress to the jobsite No shortcut allow

- All reversing of vehicles control by a banks man

- Follow road/ access/ egress signage displayed

- Comply access routes and speed limits

- Roads of adequate width to allow traffic to move safely

- Heavy equipment designated flagman during travel

- Vehicles parking at designated areas

- Comply signboard, warning board along the route

- Speed down and careful vision when driving at Conner , cross road

- Do not using phone or calling/ answer the call during driving

- Do no pass any warning tape/ Isolated area without permission

- No Overload and stock material without tied properly

- Entering Hazard Area with High Risk Activities on Operating is profited

Any modifications to working conditions or operations, such as changes in sequencing, the introduction of new equipment, or the involvement of new personnel, will necessitate a new risk assessment and the implementation of additional control measures tailored to the specific operation.

- Traffic accident due to congestion

- Effect on public health due to dust emission

- Effect on public health due to generation of noise

- Managing traffic of the project considering the rush hours on public roads

- Control dust through regular water spray on roads

- Control noise by inspection of vehicle/equipment/plants

- Traffic controllers assigned on intersections and congested areas

- Every equipment must be daily check Any oil leak must be handling Oil Absorbed materials / contaminated material will be stocked properly and transfer to the 3rd Party for handling

- Spill kit / Emergency spill kit must be keep on each vehicles for sudden maintenance or oil leak accident

[ Safety ]- Collision with moving vehicles- Slips, trips and falls- Struck by moving, falling or flying objects- Falls from working at height

[ Safety ]- Fatality- Serious personnel injury

For optimal safety on site, always use designated pedestrian walkways that are separated from vehicle and work operations Maintain good housekeeping practices by keeping access routes clear of obstructions and hazards to prevent trips, slips, and falls Conduct regular housekeeping inspections and ensure suitable netting is installed over walkways, with waste materials transferred safely from height via waste chutes Stairways should be adequately wide and deep, equipped with handrails on both sides Segregate vehicle routes, unloading/loading areas, and material storage zones to enhance safety All vehicle reversing must be managed by a banksman and equipped with audible devices Site layout and traffic management protocols should be included in training and prominently displayed on notice boards and welfare areas Use clear signage at all pedestrian crossing points and ensure personal protective equipment (PPE) is worn at all times Canopies should be provided over access ways to buildings, along with netting and signage for easy identification Assign traffic controllers at intersections and congested areas, and strictly prohibit shortcut paths on site No vehicle should enter operational areas or lifting zones without proper authorization, and distractions such as phone use while walking must be avoided to maintain focus on safety.

Control measures will undergo regular reviews and monitoring to ensure their effectiveness, with improvements implemented as necessary Any alterations in working conditions, such as changes in sequencing, the introduction of new equipment, or the involvement of new personnel, will trigger a fresh risk assessment, leading to the implementation of additional control measures tailored to the updated operations.

- Over speeding of vehicles in public areas

- Information to community regarding heavy traffic movement

- Random checking by security of vehicle speed using speed gun

- Installation of additional speed limit and stop signage on roads

- Ignition of flammable gases and combustible materials

- Faulty cables, extension leads, plugs and sockets

- RCD or ELCB rated at 30mA (milliamp) to be installed and tested before use

- Distribution board must remain locked at all times

- Maintenance undertaken by competent person

- PPE shall be worn at all times

- Only qualified and certified (3rd Party) electrician allowed to terminate panel boards

- All distribution panel boards have warning signs, checklist and contact person attached on the front door

- Cables must be hung over the ground or installed underground and not obstruct the movement/ transportation activities

Any modifications to working conditions or operations, such as changes in sequencing, the introduction of new equipment, or the involvement of new workers, will trigger a new risk assessment This assessment will lead to the implementation of additional control measures tailored to the specific operation.

- Lack of control of access to electrical networks

- Fatality or serious injury due to unauthorized access to electrical networks

- Implementation of Lock out Tag Out system

- Restrict the unauthorized access to the electrical networks

- All distribution panel boards are locked and only authorized person can open the panel boards

- All distribution panel boards have warning signs, checklist and contact person attached on the front door

- Fire provisions in presence of all hot works

- Complete PPE must be worn by all operatives

- Hot works to cease before the end of the working day and work inspected prior to completion

- All work areas kept clear of debris and rubbish

- Fire watchman must be designated during hot work operation

- Mandatory prior start of hot work must comply with three requirements: Fire extinguisher available, fire blanket to be use and certified fire watchman in place

Any modifications to working conditions or operations, such as changes in sequencing, the introduction of new equipment, or the involvement of new personnel, will necessitate a new risk assessment Subsequently, appropriate control measures will be implemented to align with the updated operations.

- Effects on people health due to smoke and fumes

- Property damage due to fire

- Provision of suitable respiratory protection

- Implementation of fire prevention policy

- Hazard material remained from electric cut must be collect and stock properly

- Collisions between people and equipment

- Regular inspections and maintenance by competent persons Daily check before working

- Only competent persons with approved certification can use equipment

- Warning signage used on equipment

- Emergency stop devices and guards used on all equipment

- Suitable and sufficient training given to all operatives

- Proper PPE worn by all persons at all times

Any modifications to working conditions or operations, such as changes in sequencing, the introduction of new equipment, or the involvement of new personnel, will necessitate a new risk assessment This assessment will lead to the implementation of additional control measures tailored to the specific operation.

Health ]- Uncontrolled access- Oil spill/leakage

[ ES&H ]- Exposure of unauthorized person to site- Soil contamination

To ensure safety and compliance with environmental standards, it is essential to restrict unauthorized access to the site Prior to entry, all equipment must undergo thorough inspections to identify any potential oil leaks Additionally, implementing secondary containment measures for all stationary equipment is crucial to prevent environmental contamination.

- Electrical equipment register containing all electrical equipment on site as well as relevant documentation

- Temporary power supply, portable electrical tools, cables will be tested and inspected every three months by competent persons, and tagged to certifying it is safe for use

- All defective items reported immediately, if defect renders equipment unsafe to use it will be removed from site until repaired

- Double insulated cables to be used on hand held tools

- All cable routes shall be designated so that to not obstructed access/egress walkways

- PPE must be worn at all times

- Use of industrial plug 44 for all power tools at site

Any alterations to the working conditions or operations, such as changes in sequencing, the introduction of new plant or equipment, or the involvement of new workers, will prompt a fresh risk assessment This assessment will lead to the implementation of additional control measures tailored to the specific operation.

- Generation of noise and vibration

- Generation of hazardous dust from wood saw and concrete grinding

- Effect on health due to noise and vibration

- Effect on health due to hazardous dust emission into air

- Control of noise and vibration through inspection of tools and equipment before entering to site

- Segregation of wood cutting area from other activities

- Control of concrete dust by using dust suckers

- Use of appropriate PPE (ear plug respiratory protection)

- Collisions between people and plant

- Segregation of working area while lifting in progress

- Only competent authorized persons with the relevant certificates and license, to operate machinery and conduct lifting operations

- All lifting operations to have a banks man at all times

- Warning signage displayed notifying of lifting operations

- Regular inspections and maintenance of equipment undertaken by competent persons

- Records and registers of all equipment to be maintained on site

- Suitable and sufficient training given to all operatives

- Lifting plan to be developed and distributed to relevant parties

- PPE shall be worn at all times

- Full implementation 333 for Safety for lifting operation:

- Use of green lifting raid by all rigger prior start of any normal lifting operation

- No person shall be on the load during lifting operation

- In case of critical lift mandatory supervision of Subcontractor

Safety, Doosan Construction Manager, and Doosan EHS representative

Any modifications to working conditions or operations, such as changes in sequencing, the introduction of new equipment, or the involvement of new personnel, will necessitate a new risk assessment Subsequently, additional control measures will be implemented to ensure safety and compliance with the updated operational requirements.

Health ]- Uncontrolled access- Unauthorized operator- Oil spill/leakage

[ ES&H ]- Exposure of unauthorized person to site- Equipment operation by unauthorized operators- Soil contamination

To enhance safety and security on-site, it is essential to restrict access to unauthorized individuals Operators must have their identities clearly displayed on the equipment they operate Additionally, a thorough inspection of all equipment should be conducted prior to site entry Furthermore, implementing secondary containment for all stationary equipment is crucial to prevent environmental hazards.

- Falling of materials and objects

- Clear and safe access and egress

- Effective material storage in segregated areas

- Regular monitoring of work areas

- Unwanted materials remove from site immediately

- Sharply or acutely exposed material must be covered

- Material must stock invidually and tidily as per type and length Small pierces must be stock in pack or box

- Material temporary stock at site must kept far from the edge to prevent falling Distance at least 1.5 m Shortly and tidily is in need

Any modifications to the working conditions or operations, such as changes in sequencing, the introduction of new plant or equipment, or the involvement of new workers, will trigger a new risk assessment This assessment will ensure that appropriate control measures are implemented to align with the updated operations.

- Social conflicts in shape of community complaints

- Effective waste management (waste bins provided around site and skips segregated, with waste disposed of by an approved licensed contractor)

- Monitoring of waste collection contractor and ensuring the dumping in licensed area

4- Installing formwork, form frame, rebar work

Asphyxiation- Entrapment- Explosion- Poor illumination

[ Safety ]- Fatality- Serious personal injury

ATTACHMENT

Attachment #1 Calculation sheet for Form work

CALCULATION SHEET OF FOUNDATION FORMWORK

PROJECT : VANPHONG 1 BOT THERMAL POWER PLANT

ITEM : CW INTAKE PUMP STATION

I Formwork of Base slab (Foundation) :

- The specifications of film faced plywood (Tekcom catalogue) Thickness of plywood, t = 1.80 (cm)

Strength limit, s = 180 (kg/cm 2 ) Modulus of elastic, E = 45,000 (kg/cm 2 )

- Vertical beam (steel box) 50x50x1.8mm

Moment of inertia of steel box: J x

Check strength : s = M/W x < R = 2100 (kg/cm 2 ) Maximum moment uner sterngth condition :

Modulus of elastic, E = 2100000 (kg/cm 2 )

- Cross beam ( 2 steel box) 100x50x1.8mm

Moment of inertia of steel box: J x

Check strength : s = M/W x < R = 2100 (kg/cm 2 ) Maximum moment uner sterngth condition :

Modulus of elastic, E = 2100000 (kg/cm 2 )

Select diameter of steel bar : D = 12 (mm)

+ h - The height of concrete: 3 (m) + g - The weight density of concrete: 2500 (kg/m 2 )

+ k 1 - The slump coefficient: 1.2 (8cm ~ 12cm)

+ k 2 - The temperature coefficient: 0.9 (28 0 C ~ 32 0 C) + The maximun pressure exerted on formwork by concrete is the lesser of: p = gh When h ≤ 0.7 p = g(0.27V + 0.78)k 1 k 2 When V ≥ 0.5 m/h and h ≤ 4 m

+ n i - partial safety factor for load: n 1 = 1.3 for load caused by equipment n 2 = 1.3 for concrete pressures

- Total design ultimate load in meters: q 1 =P 1 x b = 4140.5 (kg/m)

- Total design service load in meters: q 2 =P 2 x b = 2835 (kg/m)

- Moment of inertia : J x = bt 3 /12 = 48.60 (cm 4 )

Resistance of beanding moment: W x = 2 J x /t = 54 (cm 3 )

- Diagram is a simple beam, restraints are post

So: Formwork ensure bearing capacity

II Check the post (Vertical beam) :

- Total load on the inner brace : q = P 1 a = 1242.15 (kg/m)

- Reaction force at the post caused by total design ultimate load:

- Reaction force at the post caused by total design service load:

- Diagram is a simple beam, restraints are post

So: Formwork ensure bearing capacity

- Deflection : f = qL 1 4 /(128EJ x ) = f = 1.40 (mm) < [f]=(1/400)L 1 = 2 (mm)

So: Deflection ensure permitted limit

III.Check the cross beam :

- Diagram calculation with maximum moment

- The number of rection force : n = 3

- Reaction force at the post caused by total design ultimate load:

- Reaction force at the double waller caused by total design ultimate load:

- Reaction force at the double waller caused by total design service load:

- Diagram calculation is a simple beam, restraints are the waller.

M max = V a (2nx+n 2 y-3ny+2y)/4 = 149.1 (kg.m) < [Mmax] = 296.10 (kg.m) x

So: Deflection ensure permitted limit

III.Check area of tie rod :

- Traction exerted on tie rod : F = S x P 1 = h x a x P 1 = 2649.92 (kg)

- Area of steel bar : F a = 1.13 (cm 2 )

- Bearing capacity of steel bar : [N]k = 0.8 R a F a = 2666.8 (kg)

So: Tie wire ensures bearing capacity

II CACULATION FORMWORK FOR WALL

1/ Load exerted on side of the formwork (TCVN 4453:1995)

- Concrete pressures on parallel forms

Trong đó : g : The weight density of concrete:

H : The height of concrete: n : Partial safety factor for load

- Checking strength of tie rod

Trong đó : q : Load distribute (Kg/m) l : Beams span (m)

W : Resistance of beanding moment(cm³)

J : Moment of inertia (cm4) f : Bending deflection (cm)

E : Modulus of elastic (Kg/cm²)

J 1 = 48.6000 (cm 4 ) + Layer 2 : Vertical beam (steel box) 50x50x2

Space a00mm Beams span l = 600 mm l 2 = 0.60 (m)

J 2 = 9.30 (cm 4 ) + Layer 3 : Cross beam ( steel box) 50x100x2

Space a = 600 mm Beam span l = 800 mm l 3 = 0.80 (m)

Checking bending deflection : q = 855.00 (Kg/m) (q=( g.H + Pủ)*B1)

Checking bending deflection : q = 855.00 (Kg/m) (q=( g.H + Pủ)*B2)

III CACULATION FORMWORK FOR SLAB

Form weight - timber and plywood kg/m 2

●Temporary material added weight of area which support excess 3.5m kN/m

●Plywood 18mm(Cross to the lower part of beam material) Allowable bending stress N/cm 2

(Perpendicular to the bottom beam)

●Plywood 18mm(Cross to the lower part of beam material) Young coefficient N/cm 2

(Perpendicular to the bottom beam)

● Allowable bending stress N/cm 2 (SS400 equivalent)

● Allowable shearing stress N/cm 2 (SS400 equivalent)

●φ48.6 breaking limit of NK system (Connectionl interval H00mm） kN/support

⇒ Allowable load of NK system = 130 / n = 130 / 1.5 = 72.220 kN/support

●φ48.6 Allowable horizontal strength Allowable load of NK system kN/support

●φ48.6 Allowable horizontal strength Span L29mm, 1524mm, 1219mm, 914mm kN

●φ48.6 Allowable horizontal strength Span La0mm kN

Vibration loading 200 kg/m 2 1.30 200 kg/m 2 260 kg/m 2 325 kg/m 2

Loading from worker 250 kg/m 2 1.30 250 kg/m 2 110 kg/m 2 Live Load

Form weight - timber and plywood 100 kg/m 2 1.10 100

Item loading Intensity Heihgt-H Load Factor

Frequent Load Total Load excerter t

ｂ） Inspection of sheathing board Plywood 18mm (Perpendicular to the bottom beam)

●Bearing distance @ : ●Bearing length L : ●Bearing length L' : ●Section coefficient Zx :

●The second moment coefficient Ix:

●Bearing distance @ : ●Bearing length L : ●Bearing length L' : ●Shearing force coefficient k:

●Bearing distance @ : ●Bearing length L : = ( inside distance) (=1.219m-0.136m)

●Bearing length L' : ●Shearing force coefficient k:

●Longitudinal distance between supports @ : = ( Horizontal ： HL12C )

●Transverse distance between supports w : = ( Horizontal ： HL12C )

●Support height H : ●Temporary material added weight of area which support excess 3.5m W 1 :

Based on Article 240, Paragraph 3 of Occupational Health and Safety Regulations, the following consideration shall be made.

●Vertical load applied to vertical P :

●Allowable horizontal strength of dedicated brace HaB :

●Arrangement span of dedicated brace @ : ( Horizontal ： HL12C )

●Arrangement height of dedicated brace h : ( Horizontal bar layout distance )

●Arrangement interval of dedicated brace n : Span

According to Occupational Safety and Health Regulations, when support is assembled for formwork that is predominantly horizontal and meets "Factory manufacturing accuracy" standards, the horizontal load can be calculated using a specific formula.

Therefore, each 4 spans need one NK support's dedicated brace to prevent horizontal force of the entire examination area kN ≦ 12.000 kN ∴ OK kN

Vibration loading 200 kg/m 2 1.30 200 kg/m 2 260 kg/m 2 325 kg/m 2

Loading from worker 250 kg/m 2 1.30 250 kg/m 2 110 kg/m 2 Live Load

Form weight - timber and plywood 100 kg/m 2 1.10 100

Total Load excerter Dea Load

Item loading Intensity Heihgt-H Load Factor

ｂ） Inspection of sheathing board Plywood 18mm (Perpendicular to the bottom beam)

●Bearing distance @ : ●Bearing length L : ●Bearing length L' : ●Section coefficient Zx :

●Unit load for calculating stress W0 :

●Unit load for calculating deflection W 0 ' :

●Bearing distance @ : ●Bearing length L : ●Bearing length L' : ●Shearing force coefficient k:

●Unit load for calculating stress W0 : ●Shearing force coefficient k:

●Unit load for calculating deflection W0' : ●Section area A:

●Bearing distance @ : = ●Section coefficient Zx:

●Bearing lenght L : = ●Second moment coefficient Ix:

●Load dimension a: ●Load dimension a' : ●Load dimension b: ●Load dimension b' : ●Load dimension c: ●Load dimension c' : 【Load】

●Maximum deflection position X2 ： ●Non-static constant C3 : cm 2

Zx 37.500 is the position of maximum bending moment ) 2L

●Longitudinal direction interval @ : ●Traverse direction interval from end a : ●Traverse direction interval w : ●Support height H : ●Temporary material added weight of area which support excess 3.5m W 1 :

【Load applied to the brace material】

●Applied force on a support Pmax: kN

●Lateral force resistance limit of brace HaB : kN (914mm wide)

●Distance to arrange brace n : Support

＊ In case of flat formwork, lateral force is calculated as below.

（Values are in accordance with labour safety and sanitation law and production safety research department.）

【Total force to resist lateral force】

【Inspection of brace arrangement distance】 ΣH ≦ Bn

＊ As above, because of fitting NK 's specialized braces such as at transverse section, total lateral force is resisted. f)-1 Calculation of lateral force

Calculate according to Item 3, article 240 in labour safety and sanitation law

NIKKEN INTERNATIONAL ASIA CO.,LTD.

●Lateral force resistance limit of brace HaB : kN (914mm wide)

●Distance to arrange brace n : Support

＊ In case of flat formwork, lateral force is calculated as below.

（Values are in accordance with labour safety and sanitation law and production safety research department.）

【Total force to resist lateral force】

【Inspection of brace arrangement distance】 ΣH ≦ Bn

＊ As above, because of fitting NK 's specialized braces such as at transverse section, total lateral force is resisted.

NIKKEN INTERNATIONAL ASIA CO.,LTD.

PROJECT : VAN PHONG 1 BOT THERMAL POWER PLANT

LOCATION : Ninh Phuoc commune, Ninh Hoa district, Khanh Hoa province

SUB-CONTRACTOR : CONSTRUCTION CORPORATION NO.1 - JSC

Vertical NK18 Horizontal HL12C Brace NKB1212K Vertical NKS15

Vertical NKS15 Upper Vertical BC150 TSH2N

Vertical NK18 Horizontal HL12C Brace NKB1212K Vertical NKS15

Horizontal HL09C TSH2N Upper jack

Attachment #3 Calculation sheet for water pump of dewatering-Pump station

=>Select the surface drainage plan

In which: k: Permeability coefficient (m / day) k= 8.64 m/day

Amount of water flowing into the foundation pit:

In which: C - width of rectangular foundation pit = 65.88m

: B - length of the rectangular foundation pit = 57.88m

: ɳ - coefficient, can be checked in table 9 2

1 Based on the geological section of the bore holes BH42 and BH44, the pump station location is hard clay and weathered rock with small permeability coefficient.

2 Elevation required to lower the water level and groundwater level is 0.5m lower than the bottom of the foundation pit

3 Foundation pits are dug in the form of open excavation

4 Area of foundation pit is small

II Methods of surface drainage

1) Calculated from the distance from the edge of the foundation to the foot of the wall, the bottom of the ditch trough is

0.3m wide, measuring 1% - 5% slope, simultaneously have sump pit.

To ensure proper drainage, maintain a height difference where the bottom of the drainage ditch is 0.3 to 0.5 meters lower than the excavated surface, and the bottom of the sump pit should be 1 meter lower than the bottom of the drainage ditch (refer to Figure 9.2).

The typical diameter of a water collection pit ranges from 0.7 to 1 meter, with walls constructed from bricks, concrete pipes, or lean concrete It is essential to implement soil guard walls or temporary holding measures, along with a graded filter at the bottom of the sump pit, utilizing 0.3 meters of macadam or gravel The design layout of the sump pit will be illustrated in the accompanying drawing and can be modified to suit the specific site conditions.

III Calculating the pump selection

The volume of water entering the foundation pit can be estimated using empirical methods or suction tests Alternatively, it can be assessed through the large well method, where a rectangular foundation pit is treated as a large well with a diameter of 2 meters By calculating the water flow in the sump pit, one can determine the necessary pump capacity.

Refer to soil investigation report, take from borehole BH42, calculate the amount of water that penetrates to the foundation pit with high water level: +0.07m

How much depth is Water collection pit ?

How is this permeability coefficient calculated ?

*Amount of rainfall discharge is calculate by this formular

During the rainy season, the daily rainfall can be quantified by the variable 'g', which averages 8.1 mm The maximum rainfall factor is represented by 'k', set at 3, while 'm' accounts for water flow from surrounding areas into the foundation, with a chosen value of 1.50.

Hence, the total amount of water which need to pump out

The pump will be operated regularly to ensure GWL should be lowered to 0.5m under excavated bottom

=> Choose 03 pumps (10HP) with a capacity of 96m3 / h

Calculate the total capacity of the pump N

H: Total height of bottom , suction range and water column losses due to resistance forces (m) a: Safety factor equal to 2 ɳ 1: pump capacity is taken from 0.4-0.5 ɳ 2: Engine power 0.75 - 0.85

R: The radius of depends on K taken from table 9.3

H: Depth of the water level is stable to the bottom of the foundation pit as designed

The record of rainfall table, source from http://www.mpi.gov.vn/Pages/tinhthanhchitiet.aspx?idTinhThanh#:~:text=Kh%C3%AD%20h%E1%BA%ADu%20

Kh%C3%A1nh%20Ho%C3%A0%20v%E1%BB%ABa,80%25%20l%C6%B0%E1%BB%A3ng%20m%C6%B0a%20c

This table is translated in English please.

Is this amount of Ground water ?

This rainfall intensity is too small in tropical area.

From Meocean and Hydrodynamic Study report, Hourly rainfall intensity is much larger than the below table.

Average of rainfall is not annual, but maximum rainfall during construction duration should be taken.

What is the other area ?

Ground water will infiltrate from surrounded area to the central area of excavation bottom

How is this GW dewatered ?

Attachment #4 Calculation sheet for concrete supply of massive concrete

Thời gian đổ/Pour time: h 1 = 16 h

Tổng thể tích khối đổ/Total capacity : V 2 = P x n 1 x h 1 = 2016 (m3)

Hệ số an toàn/safety factor : V 2 /V 1

29x41.035 m2 bê tông/ Concrete 1839 m3 (Strength: fc0Mpa )

Số lượng/ quantity 3 xe bơm/pumps (1 back-up pumps)

-Tương tự cho các 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.

Tính toán số lượng xe bê tông 8m 3 tối thiểu

Chu kỳ một xe 28 phút/Time periods 28 minutes

Thời gian chờ + đổ = 16 phút (~42m3 /h cho năng suất xe bơm bê tông)

Waiting time+castingminutes(~42m3 /h capacity of truck mounted line pump) start ● 16 min ● 16 min ● Finish1 period

Theo biểu đồ 1 bơm cần 2 xe (dự trù 1 xe)

Follow the chart: 1 pump need 2 concrete trucks (1 stand by)

Dự kiến trạm sẽ cấp từ 3 bơm nên số xe bê tông tối thiểu cần thiết cho mỗi trạm như bảng bên dưới

VIMECO will arrange 3 pump trucks hence, the minimum of concrete trucks which need to provide

2 Checking with the capacity of concrete supply from Vimeco

As confirmation from Vimeco, Total of capacity of product Mix concrete is:

2) Xe bơm bê tông/ Truck mounted line pumps

3) Xe bê tông/ Agitator truck ( 8m3/ car)

4) Thời gian đổ bê tông/pouring time

6) Hệ số an toàn / Safety factor

Trạm/BatchingVIMECODistance (km)

Checking the Pump truck and the concrete truck:

Qconcrete truck= 10 >9(as requirement) OK

Attachment #5 The design for foundation of Tower crane

- TCVN 9362-2012: Specifications for design of foundation for buildings and structures

We use the parameter at the Bore Hole BH-42 at the level -10.56m (layer 6B)

For safety, we use the compression strength in the saturated case with minimum value:

Effective width of foundation ho = 1.45 m

Compression strength of rock when it satured R = 700kN/m 2 Calculation compression strength of rock R c = 583kN/m 2

2 Loads on foundation including 2 case: Working and none - working

Two forces impact on foundation central corresponding:

According to the catalog of Crane that issued by contractor, forces impact on foundation.In detail, the wind velocity calculated into catalogue is 150km/h (V 0 A.67m/s)

Thus, according to TCVN 2737-1995, the pressure of wind is:

In addition, refer to appendix E, TCVN 2373-1995, In Ninh Hoa district, wind zone is II.A, therefore, W 0 daN/m2.

In conclusion, It is safer to use the figure as catalogue to check the foundation

F2lv= 157 T Two forces impact on foundation central corresponding:

3 Foundation calculation in none-working case:

Total weight in bottom foundation: Pn = N1+Fn= 270.1 T

Moment in bottom foundation: M= 177 Tm a Check on stability

Anti-turn over moment: [M]cl=Pn*B/2= 1060 kNm

Turn over moment: Mn= 177 Tm

Ratio between anti and turn over moment: r= 6.0

Conclusion OK b Check constraints under bottom foundation

Conclusion OK c.Calculation longitudinal rebars:

4 Foundation calculation in working case:

Total weight in bottom foundation: Plv = N1+Flv= 266.1 T

Moment in bottom foundation: Mlv= 349 Tm a Check on stability

Anti-turn over moment: [M]cl=Plv*B/2= 1044 kNm

Turn over moment: Mlv= 349 Tm

Ratio between anti and turn over moment: r= 3.0

Conclusion OK c.Calculation longitudinal rebars:

Conclusion OK c.Tính toán thép móng

Conclusion OK max W tt tt x m x

S < [S] = 8cm OK Settlement of Soil under Foudation Calculation follow: TCVN 9362-2012

E 0 – Modul Settlement of Soil (According to Tassios, Anagnostopoulos)

Where: a - Coefficient, a@ if N>15 and a=0 if N15 and a=0 if N

Tiêu đề	Method Statement For Construction Of CW Intake Pump Station
Thể loại	For Approval
Năm xuất bản	2020

Định dạng
Số trang	138
Dung lượng	17,38 MB