Desertlab is a Quality Control Engineer working in the Infrastructure projects in Middle East for more than 10 years.
This article will give you a basic idea on how to write a methodology in the construction of telecom network (i.e. installation of duct pipes, construction and installation of concrete chambers and testing of the installed telecom network.
An example below of what we usually do at site.
The purpose of this method statement is to outline the materials, labour and workmanship required to undertake the activity in a safe and controlled manner, complying with all Relevant Legislation, Standards and Codes of Practice.
Scope of Work
The scope of this method statement covers excavation and installation for D54/D56 duct pipes, chamber and Pull boxes construction, duct pipe installation under road crossings, backfilling, placing of warning tape and mandrel test in accordance to the Contract Specification and international standards applicable.
Plant and Equipment
The following equipment are required.
- Survey Equipment and Accessories
- Measuring Tapes, Spirit Levels, Plumb Line
- Transit Mixer
- Excavator / Backhoe
- Water Tanker
- Compactor (Plate or Roller)
- Clamps and Belts
- Mechanical Vibrators
- Cutting & Bending machine
- Testing Tools and Apparatus
- Permit to Work should be approved and in place prior to commencement of work.
- Provision of No Objection Certificates from all related service authorities when required.
- Approval of shop drawings and verify all the applicable drawings for the latest revision.
- Obtain approval of all materials related to the activity.
- Liaise with Employer to confirm the start date, program of work and any matters related to the Health and Safety, Security and Environment.
Excavation and Formation Preparation for Trench and Chambers
- Prior to start excavation, survey and setting out of the D54/D56 uPVC duct pipe and chambers shall done as per approved drawings.
- Equipment to be used for excavation will depend on the type of material to be excavated.
- The trench shall be excavated to the required width and depth; the trench bottom shall be free from stones and leveled.
- Prior to the installation of duct pipes, sand surround shall be placed as per the approved shop drawing.
Installation of D54/D56 uPVC Duct Pipe:
- Duct pipes will be shifted to site from store with proper care, to avoid damage to the pipe.
- The lifting of pipe will be done by nylon slings and the pipe will be shifted on a proper vehicle.
- Just before laying, each pipe will be cleaned and inspected for defects, both inside and outside. Any damaged pipes will be removed.
- The D54/D56 uPVC shall be laid on the trench bottom and proceed with jointing or may be jointed above the ground and lowered into position on the trench bottom or as per instructions by the Engineer.
- All duct banks (4-way/ 6-way/ 9-way) shall be constructed as per the approved shop drawings.
- All ducts shall be provided with pull cords.
- Pipe ends of the future / plot connections shall be fixed with end cap.
- After the completion of duct laying all the ducts shall be checked for horizontal and vertical alignment and shall be supported properly during surround placing works.
- Duct pipe surrounding / protection shall be done as follows:
- The surroundings, the spaces between the ducts and 100mm on top of the duct pipe being filled with sand (free from stones) as per the approved shop drawing.
Concrete encasement shall done for the duct pipes under the any traffic and/or paved areas.
- C20/20 blinding shall be placed after the trench excavation as per the drawing.
- Prior to fixing of formworks and steel reinforcements as per approved drawing, duct pipes shall install.
- Concrete encased ducts shall be reinforced concrete grade C40/20.
- Concrete encased duct external surface shall be coated with the 2 coats for coal tar epoxy with min 400 micron per coating. If concrete is case against the soil surface no coating required on sides.
Backfilling and Mandrel Testing
- Backfilling of trenches up to FGL using layer of approved suitable materials.
- Placing of warning tape as per level specified in the approved drawing.
- After the completion of compaction between two jointing chambers, a cylindrical brush and a Mandrel shall be passed once through each “way”. The Mandrel shall follow the brush to minimize possible breaking of the D54/D56 uPVC.
- Pull aluminum or wood test mandrel through duct to prove joint integrity and test for out-of-round duct.
- Provide mandrel equal to 80% fill of duct.
- All tests shall be carried out in the presence of the Engineer.
Installation of JRC Chambers and Pullboxes
- Setting out for chamber as per approved shop drawings.
- Excavation for chamber in accordance with the approved shop drawings. Excavation shall be one stage depending on sub-soil conditions and depth of manhole. Final 100mm to formation level will be done manually and prior to blinding. Dewatering system will be provided if required as noted.
- Compaction of formation layer prior to blinding shall commence .
- Polythene sheet of 1000 gauge shall be provided under all blinding concrete.
- Casting of blinding concrete as per level and thickness shown on approved shop drawings. Blinding concrete shall be Class C20/20 with minimum compressive strength of 20 N/mm².
- Primer shall be applied on the blinding concrete and waterproofing membrane shall be installed.
- Transport the precast chambers to the site with clamps and belts using crane.
- Installation of chamber as per approved location, orientation, levels and approved shop drawing.
- Final level checking shall be done and level sheet shall be prepared.
- Connect the ducts to the chamber.
- Protection board shall be fixed as per the approved drawing.
- Backfilling around the chamber will be done after the ducts connection as per specifications.
- Install all the chamber accessories such as grating, cable bearers, ladders as per approved drawings.
- Install precast cover slab including D.I. Cover and frame.
- Clean the area.