This article is about Excavation, Trenching and Backfilling Requirements for Copper Cable Installation of OSP Telecom Distribution System as per International Codes and standards.
Excavation, Trenching and Backfilling Requirements for Copper Cable Installation
General
- Ensure that safeguards, warning devices and personal protective equipment is employed at all times.
- Check that all debris has been removed and that the trench bottom is leveled.
- Ensure that all spoil is kept at least 600mm from the trench edge during the excavation.
- Ensure that trenches or other excavations that are 1.5 meters or more in depth shall be safeguarded by shoring or sloping the trench walls in accordance with “GTE 622-105-209”.
- Verify that all conduit ends (including road crossings, pole risers, between pedestals and/or cabinets) are plugged or sealed to prevent sand or debris from entering the duct prior trench backfilling.
- Verify that the minimum 50mm sand or selected fill material has been placed in the trench bottom before cable laying operation commenced.
- Verify that hand digging or excavation is employed when the presence of underground utilities is suspected or the excavation is around or near electrical substations.
- Verify that marker posts is placed at the ends of conduits placed at roads, railroad, pipeline, and utility crossings during the trench backfilling operations.
Manhole
- Verify that excavations for precast manholes provide a minimum clearance of 205 mm between the exterior wall surfaces (ends and sides) of the manhole and the surfaces of the walls of the excavation.
- Verify that a minimum of 100 mm of sand or other base material is placed in the bottom of the excavation and compacted and graded to level prior to placement of a precast manhole.
- Check and verify that the excavated trench for the new manhole is the proper depth prior placing the form work.
- Check and verify that the excavated trench for the new manholes to be constructed in vehicular traffic areas will be having the minimum depth of cover of 355 mm from the MH roof.
For Direct Buried Cables
- Verify that the minimum cover requirements of 600 mm for copper buried cable is maintained for the excavated trench prior cable laying commenced.
- Ensure that telecommunication copper cables and power cables are not directly buried together in the same trench by the “Random Separation” method. Fixed separation as specified in Table 2 and paragraph 4.5.2.1 of SAES-T-928 is required prior commencing trench backfilling.
- Verify that orange colored detectable marker/identification tape is placed in the trench above the cable in accordance with Standard Drawing AA-036748, prior the final trench backfilling.
- Verify that the excavated trench for buried service wires installation will provide the minimum cover of 500mm (20″) over the cable.
- Check and verify that a ground resistance of 25 ohms or less is established for the installed main electrodes that consist of a minimum of 2.44 m (8 ft.) prior trench backfilling.
- Check and verify that the excavated trench for Pedestal installation and the trench backfilling is as per Standard drawing.
Conduit
- Check and verify that the excavated trench for the telecommunication main and lateral conduit sections in traffic areas will provide the minimum ground cover of 760 mm from top of the encasement.
- Check and verify that the excavated trench for the telecommunication main and lateral conduit sections in non-traffic areas will provide the minimum ground cover of 610 mm from top of the encasement.
- Verify that all lateral or stub-out conduits (installed for future connection/extension) are placed in the same trench line with the main conduits, they are extended a minimum distance of 12 m, or to the point where they leave the main trench prior trench backfilling.
Pipeline crossings
- Check and verify that the excavated trench will provide the minimum 1m vertical distance between the bottom of any pipe and the top of the buried, concrete encased conduit back.
- Check and verify that the excavated trench is extend for a minimum distance of ten (10) meters on each side of the pipeline.
- Check and verify that the excavated trench for any service point (manhole, pedestal etc.) on telecommunication cables is not closer than 25 m to any pipeline in the corridor.
Standards Codes and References for Telecom Excavation, Trenching and Backfilling
1. SAES-A-114, Excavation and Backfill.
2. SAES-T-603, Telecommunications -Safeguards and Warning Devices.
3. SAES-T-629, Telecommunications Buried Cable and Wire.
4. SAES-T-903, Outside Plant Electrical Protection and Grounding.
5. SAES-T-911. Telecommunication Conduit System Design.
6. SAES-T-928. Telecommunications – OSP Buried Plant.
7. AA-036748, Buried Telephone Cable /Distribution Wire Installation Details.
Telecom Closet / Telecom Equipment Room Size And Location.
Telecommunications Infrastructure Design Process.
ANSI/TIA/EIA 568-B Commercial Building Telecommunications Cabling Standard.
Telecommunications Outside Plant Systems Design SAES-T-938 Download.
Copper Cable Direct Buried Installation and Commissioning | Telecommunication