Method Statement for Future and Split Ducts

CONTENTS

1. Purpose

• Scope of Work

• Definitions

• References

• Materials

• Plant  & Equipment

• Safety

• Prior Activities

• Procedure

1. Responsibilities

1. Attachments

1.0    Purpose

1. To ensure that future, split duct and related activities are executed safely and in

         accordance with the contract requirements and that all quality assurance / control     

         activities are conducted in a systematic manner, works are inspected and

         conformance is verified and documented.

2.0    Scope of Work

• This procedure is applicable to the following works associated with the project titled,

          New 2k Runway – Main Runway Works”- contract number NRTW-1008-CN

• This method statement outlines the procedures to be followed in the construction of

          future & split ducts at locations shown on Contract Drawings and as directed by

         Client / Consultant.

              Two types of ducts shall be constructed in this contract:

• Split Ducts.
•  Future Ducts.

3.0    Definitions

               3.1   CM                      Construction Manager

            3.2   SE                       Site Engineer

            3.3   CS                      Chief Surveyor

            3.4    ME                     Material Engineer

            3.5  ESHO                  Environmental, Safety, and Heath Officer     

• References

     4.1  Specifications:         Vol 3 – Section 9  – Part  A , B & E

         4.2   Drawings:              Vol 2 – Section 8 – Part E – Electrical and Mechanical

                                                            Vol 2 – Section 8 – Part B – Civil, Mechanical and Navaids

                                               Vol 2 –  Section 8 – Part G  – Electrical Infrastructure

         4.3     B.O.Q                  Bill of Quantities.                 

• Materials

5.1 uPVC Pipes

5.2 Class 25/20 Concrete

5.3 DI Pipes

5.4 GRP Pipes

5.5 Draw ropes

5.6 End caps

5.7 Warning tapes

5.8 Traffic cones

5.9 Duct markers

5.10 Formwork/Shuttering

5.11 Traffic Signs

5.12 Safety barrier

6.0  Tools, Plant & Equipment

6.1 Electrical grinder/saw

6.2 Excavator

6.3 Loader

6.4 Hand shovels

6.5 Picks

6.6 Generator

6.7 Concrete plant

6.8 Air compressors

7.0            Safety

         7.1         Prior to the commencement of any activities, the workforce will receive an induction        talk on the Project site safety requirements. This induction talk will include both   activity safety issues, as well as general safety requirements.

     7.2          Where possible hazards may arise from filling activities, the necessary safety                                  measures will be taken to prevent accident or injury at all times. This may include                              barriers, warning tape/ Net, signage, watchman, and proper lighting.

•         Where work upon existing services may be required, the necessary work permits         and safety equipment should be obtained prior to the activity commencement.
  •         ESHO will enforce that Personal Protective Equipment be worn by site personnel at             all times during construction activities.
  •         Heat Stress Training will be provided.
  •         Provisions of adequate cool drinking water, shade, and salt water tablets will be in       place.
  •         Plant & Equipment will be provided back-up alarms, lights, and all other applicable    safety Devices.
  •         For AOA work, safety requirements as defined per Section 107 will be implemented.           Specific safety training will be provided to personnel for AOA work.
  •         Safety Hazards and Precautions

	a)- Strike UG Services: Use Locator and/or hand excavation (trial holes)
	b)-Excavation Collapse:   Batter sides to safe slope or provide shoring (as directed by                            Geotechnical Consultant) and subject to Engineer’s approval Keep vehicles/equipment safely away from excavation edgeKeep spoil at least 2.0 meter away from edge   c)- Fall into excavation:   Provide fencing, guardrails or flagging tape around edges.Provide safely fixed ladders (every 50m)Provide banks man when operating equipment near excavation.   d)- Falling Objects:   Stand clear during lifting operationsWear hard hats   e)- Equipment & Vehicles:   Use Safety beltsSlow down and obey speed limitsProvide “back-ups” alarmsProvide banks man when operating equipment near excavation.   f)- Confined Space:.
	Check excavations for snakes and scorpions before entry
	Take precautions against flooding
	Develop rescue procedures

8.0               Prior Activities

•           Before commencing any part of the works, the CM/SE shall ascertain the actual            locations of all existing services. If the works conflict with any existing service or     road,    he should obtain the Engineer’s approval for the protection or relocation          (diversion) methods before commencing work.
  •           Obtaining requirements for future Ducts from the appropriate Service Authorities     should be the first step. This should be done at earlier stages when the notices of             intents are sent to the concerned departments. Also the typical section and    extension of duct beyond the road edge is to be confirmed by them.
  •           Final approval of the future duct layout should be obtained from the Engineer,      through the shop drawings submittal.
  •           As for the split ducts requirements, the location of the existing services with types and levels should be identified by the Survey Team. This is done through the trial pits    digging carried manually to locate these services
  •           Approval from the concerned service Authorities for the kind of protection/relocation or lowering of services should be sought.
  •           Final details of kind of protection or relocation/lowering are to be approved by the            Engineer.
  •           After the shop drawings approval, checking requests for site activities are submitted      to the Engineer.

• Procedure

All activities carried out will comply with the OAJ-JV Inspection Test Plan which reflects the testing requirements of the Contract.     

9.01   General

9.01.1            Construction of the future & split ducts have to be properly coordinated with other      activities (sewerage, storm water, road works…etc) at the same area and should        basically follow the approved programme of works.

9.01.2            When the type of activities involve sewer and drainage works, excavation for           sewer lines which involve the deepest excavation comes first, followed by storm         water works (again, depending on depth). Care should always be taken if the           existing services interfere with these excavations.

9.01.3            Sequence of works for earthworks and ductworks depend whether the section is       in cut or in fill. In cut areas, excavation precedes ducts and protection works, until          the appropriate level is reached. In fill areas, embankment layers are        constructed up to the ducts top level after which excavation for ducts starts. Split      ducts can be constructed simultaneously with the future ducts, depending also on     their design depth/level.

9.02     Split Ducts

9.02.1            Split Ducts shall be used for protection of existing cables / services           crossing  the new carriageway and at locations approved by the Engineer.

9.02.2            Excavation to expose the existing services for protection has to be carried

                     out according to specifications and to MS-1012

9.02.3           Prior to commencing any works, the CM/SE shall verify on site the proper

                      location, routing and depth of existing concerned cables/services.

           The method of identification shall be based on the Contract Drawings; trial pits findings and notices of intents replies from the concerned departments. Excavation to uncover the services shall be done manually.

9.02.4            The CM/SE shall submit working drawings detailing the findings and his proposal for their protection to the Engineer for approval.

9.02.5            Excavate around the existing cable to allow for placement of shuttering. The duct shall be excavated to the exact width and depth, as per the approved shop drawings. Installation and handling of shattering/formwork should be carried out as per the specifications.

9.02.6            Cut the uPVC pipes longitudinally for the required length of protection. Splitting can be made on site by a portable electrical disc grinder / saw.

9.02.7            Install the split pipe around the cable and wrap it twice with polyethylene sheeting, 0.6mm thick and make sure that both ends of pipes are properly protected to prevent concrete or soil from entering the duct.

9.02.8            Pour concrete as specified in the approved shop drawings.

9.02.9            Remove shuttering and backfill with suitable compacted material.

         9.03     Future Ducts

Future Ducts shall be constructed at locations shown on Contract Drawings and /

or as directed by Engineer. Ducts are to be provided as required by the relevant                              

authorities, in response to the Notices of intents sent to them and according to the       approved shop drawings by the Engineer.

9.03.1            Prior to commencing any works, the CM/SE shall notify the Engineer of his intentions to carry out any protection activities to existing services that may conflict with his planned works.

9.03.2              The CM/SE shall submit working drawings for the Future Ducts.

9.03.3              The construction of future ducts shall begin before starting the construction of road layers. Excavation shall be to the exact length, width and depth of the ducts as per the approved drawings and shall be carried out by a mechanical excavator. Proper care should be taken however for the locations of existing services if any.

9.03.4             The length of ducts shall extend beyond the road edge / footpath as specified                                 in the relevant authorities’ requirements.

9.03.5             Shattering/formwork shall be erected and handled as per specifications.

9.03.6             Position pipes on concrete spacers or square blocks spaced at 3 meters intervals.

                       Provide 15mm dia nylon draw ropes inside pipes for the entire length, and provide

                        PVC end caps for pipes less than 300mm dia and plywood planks for 300mm dia

                        And bigger ducts in order to plug ducts ends.

9.03.7                 The length of each draw rope shall be such that at least 1m extends from each

                           End of the duct. The free ends of draw ropes shall be attached to duct marker as

                           shown per drawing no. PGAD745/1008/C/813

9.03.8                 Pour concrete or use aggregates as per approved shop drawings.

9.03.9              Curing of concrete shall be carried out .

9.03.10            Remove shuttering and backfill with suitable compacted material .

9.03.11            Continue with embankment construction but with extreme care especially during

                        laying and compaction of materials above duct.

9.03.12   Install utility duct markers as specified in Contract drawing No.                                                        PGAD745/1008/C/813

9.03.13            Testing of concrete shall be carried out according to specifications.

9.03.14            After completion of works, the area shall be cleaned from any pipes, ropes and                                loose material. 

              Cleaning and Testing of Ducts

Throughout the construction, the interior surface of all pipelines should be kept clean and free from all superfluous matter. As per the Service Departments requirements, and on completion of the ducts construction, two mops of appropriate sizes connected to each end of an iron mandrel shall be passed twice each way to clean the ducts and to remove foreign matter as per .

10.0     Responsibilities

It is the overall responsibility of the CM, to ensure that the identification, protection

and/or removal/rerouting, to existing services, are conducted in a safe, methodical

Sequence as defined by this method statement.

The CE / SE will deal with the investigation of existing services from the

Authorities.

The ST will accurately plot and record all existing services on the site, and then

Set out the proposed split & future ducts (alignment and depth).

The ESHO task is to follow up all safety requirements on site, since duct workers

Involve hazardous activities such as excavation for pipes, trenches protections

And others miscellaneous work.