Backfilling Method Statement

Hydro Agricultural Development of South Lebanon Irrigation and Water Supply Scheme Conveyor 800

Water Resources & Development Co.S.a.r.l

Construction Method - Backfilling

Contents 1.

Introduction ................................................................................................ .................................................. 2

2.

Scope ........................................................ ................................................................. ....................................... 2

3.

Definitions......................................................... ................................................................. ............................ 2

4.

Responsibilities.......................................................... .............................................................. .................... 2

5.

Methodology .................................................................................... ............................................................. 3 5.1

Prior Activities .............................................................. .............................................................. ......... 3

5.2

Execution ........................................................................................................ ....................................... 3

5.3

Precautions ............................................................................................................ ............................... 4

6.

Risk Assessment ............................................................................. ............................................................. 4

7.

Health and Safety Requirements......................................................... .................................................. 5

8.

Environmental Requirements.............................................................. .................................................. 6

9.

Quality Control Requirements ............................................................. .................................................. 6

10.

Resource Allocations ........................................................................... .................................................. 6

11.

Document References ......................................................................... .................................................. 7

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Backfilling 1. Introduction This method statement outlines the backfilling works associated with the construction of Hydro Agricultural Development of South Lebanon Irrigation and Water Supply Scheme CONVEYOR 800 Project. The process describe the uniform work methods that are carried out during backfilling operations, taking into consideration all safety measures and environmental requirements.

2. Scope This procedure is applicable to all backfilling works requested for the construction of the Qelia Canal, its related structures and maintenance roads. It intends to co-relate and control all the tasks required in order to achieve satisfactory completion of backfilling activities on the project.

3. Definitions All terms used in the development of this procedure are defined in Item Specifications.

4. Responsibilities The construction manager is responsible in ensuring the implementation of construction procedure and method statement, supervising the work and reporting the progress of work to the planning engineer. The QA / QC engineer is responsible in monitoring the execution and performance of the works in relation to this method statement, approved drawings and technical specifications. The site engineer is responsible for all ongoing activities on site, ensuring it is in accordance with the schedule and the construction drawing. The safety officer is responsible in ensuring that all activities are carried out safely at site, establishing the site safety plan, conducting continuous safety inspection and stopping any unsafe work.

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The worker is responsible to properly wear the protective equipment provided and obey all the safety rules. He must also perform the work as described in the method statement.

5. Methodology 5.1

Prior Activities:

1. Use suitable material obtained from excavation of conveyor and from reservoir areas to construct embankments, if this quantity is inadequate use materials from approved borrow areas or quarries. 2. Stock the backfill material in piles and add appropriate water quantity. 3. Submit details to the Engineer of the material to use including at least three sets of test results comprising sieve analysis, optimum moisture content and maximum dry density. 4. Prepare access to the working area and plan for the dump truck and plant movements. 5. Ensure that all repair work for concrete surfaces -if any- have been done and inspected. 6. Remove all vegetation, topsoil and any other unsuitable overburden from areas on which fill is to be placed. 7. Compact the existing surface using a steel vibratory roller. 8. Carry out survey to obtain original surface levels and submit the results to the Engineer for agreement. 9. Set out and mark the limits of embankment fill using a steel rod driven into the ground with a maximum distance of 10 meters between rods, where the offset distance from edge of embankment depends on the height of fill and the edge slope. 10. Indicate the reference level of the layers on the offset rods or on shuttering or concrete sides -if any- taking into consideration the difference in levels between the final edge of embankment and the offset rods. 11. Check these rods and the marks on them routinely.

5.2

Execution:

1. Use a front end loader or hydraulic excavator to load the fill materials into tippers and transport it for spreading by dozer / hydraulic motor grader combination. 2. Place the fill in successive layers not exceeding 300 mm after compaction. The layers shall be parallel to the final fill surface covering the full width and length of the area to be filled to ensure the area is built up evenly.

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3. Remove oversize materials with a maximum dimension greater than the compacted layer thickness, and ensure that no segregation is allowed by thoroughly mixing on the surface with a motor grader. 4. Add water required to achieve optimum moisture content by applying it evenly and uniformly over the area concerned. 5. Compact each layer by using steel vibratory rollers, in a series of continuous operations in a longitudinal direction over the whole width of the layer so that each roll laps over half of the previous roll. 6. Use hand compactors in confined areas adjacent to structures where heavy equipment may cause damage. 7. Carry out a compaction test as to the satisfaction of the engineer at the end of each layer. 8. Recheck embankment levels at the end of backfilling to ensure they are in compliance with the drawings. 9. Finish the fill slopes with neat lines disposing all loose rocks and uncompact material.

5.3

Precautions:

1. Ensure that the fill material do not contain boulders of height more than 2/3 of the compacted thickness of the layer. The Fill shall not include any substances that are injurious to the permanent works such as peat, timber, tree roots or stumps, refuse, degradable matter, organic content, chlorides, sulphates or other chemicals. 2. Cease the work when disposed fill material that have not been compacted becomes too wet due to rain or other causes until the fill dries and its suitable to resume compaction, if necessary harrow the material. 3. Decrease the depth of layer, increase the number of passes or change the type of equipment when the dry density is not obtained. 4. Ensure that water sprays are not directed on the fill with such force as to cause fines to be washed out. 5. Place the fill so that the surface has sufficient camber to shed surface water and to avoid ponding.

6. Risk Assessment Works shall be carried out in line with the issued Health and Safety, Control, Monitoring and Inspection Plan. Risk Assessment sheet of each activity shall be prepared by our specialist before commencing any activity.

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7. Health and Safety Requirements To ensure a safe working environment during the entire backfilling process, it is necessary to control all occurrences of injuries and damages to equipment and properties in accordance to the approved HSE plan and the following mentioned measures: 1. Check that safe working condition is obtained and identify any specific site hazards prior to any backfilling works. 2. Ensure that all personnel follow the Health and Safety Rules by attending Site Safety Induction Courses relevant to their work activities. 3. Confirm that all operators and drivers are equipped with valid driver’s / operator’s license. 4. Alert all drivers to use safety belts, slow down and obey speed limits. 5. Ensure that drivers are not operating the machines in a manner likely to endanger themselves. 6. Employ authorized signalman with the operator or driver when necessary. 7. Check that any machine or equipment at site, is authorized, inspected and certified by qualified person prior to using. 8. Carry out a periodic preventive maintenance on all equipment and machines to ensure it is in a good working condition. 9. Assign a stand-by man with radio to coordinate for providing a rescue team when the emergency action is required. 10. Provide Frist Aide Facility on working site in case of minor injury treatment. 11. Enforce all workmen, supervisors and engineers to wear proper personnel protective equipment including safety helmet, safety shoes, ear / eye protectors, dust mask, gloves and / or high visibility vest. 12. Agree with the Engineer and the relative authority for all traffic routes and access points used for fill material delivery in such a way to minimize contact with pedestrians prior to commencement of operations. 13. Provide and Maintain barricades and signs sufficiently when required, as precautionary measures during the entire stage of construction, to protect the work, workmen and safety of the public. 14. Ensure that the weight of dump truck containing fill material is not exceeding the limited weight allowed by the local traffic law. 15. Take all precautions to avoid fire in storage of fuel and oil.

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8. Environmental Requirements Backfilling works shall be carried out in accordance with requirements as described in the Contractor's Environmental Management and Monitoring Plan, taking into consideration the following precautions: 1. Ensure that there is no dumping of garbage, waste, construction debris, motor oils and the same on the site or on the adjoining vegetated areas. 2. Mark fuel containers with contents and prohibit its storage near to watercourses or drains. 3. Identify any watercourses surface or field drains that maybe affected by the work. 4. Take preventive measures to contain water containing silt or sediment and prevent it entering drains and water courses. 5. Take steps to ensure that water is not wasted during watering the fill. 6. Alert all residents or occupiers near working area for the risk due to noise and dust. 7. Minimize noise by selecting pertinent plant and equipment. 8. Take Arrangements for controlling the flying dust created during backfilling activities. 9. Wear eye goggles and use dust mask to avoid eye wound and dust inhalation. 10. Check, cover and secure all fill materials prior to its movement and prevent overloading and overfilling of transporting vehicles. 11. Ensure that the transportation path from site to stock area is always clean and free from soil or waste matter that may fall down during transportation. 12. Assign areas for washing vehicles wheel before leaving the site to public roads. 13. Carry out appropriate survey on roads that will be used for transporting fill material before commencing any works. 14. Reinstate all damages accompanying transportation of the fill material. 15. Switch off all vehicle engines when not in use to minimize combustion emissions.

9. Quality Control Requirements Quality control shall be as per the checklist and corresponding inspection plan to be developed in line with the work to be constructed. The inspection checklist filled by QC inspector shall include the specific requirements, safety and environmental measures.

10.

Resource Allocations 10.1 

Man Power: Site Engineer:

01

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

Supervisor:

01



Flagman:

01



Unskilled Labors:

04



Operators:

As Required

10.2

Equipment / Machinery Required:



Excavator:

02



Wheel or Chain Loader:

02



Tipper Trucks:

08



Bobcat or JCB:

02



Motor Grader:

02



Vibrating Steel Roller:

02



Hand Compactor:

02



Water Tanker:

02

The major equipment used in for site clearance works include, but are not limited to the above.

11.

Document References

All backfilling works on the project shall be executed as per the following sections of the technical Specification - Volume 2.2: 

Section 1.4 - Filling



Section 5.2.1 - Crushed Stone Materials



Section 5.3.1 - Natural Road Materials



Section 5.3.2.2 – Classification of Compaction



Section 5.3.2.6 - Treatment of the Roadbed



Section 5.3.2.7 - Fill

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Backfilling Method Statement

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