Underwater laying
Underwater power cable The route selection shall meet the requirements that the cable is not vulnerable to mechanical damage, can implement reliable protection, is easy to lay, and is economical and reasonable, and shall comply with the following provisions:
1 The cable should be laid in the water area where the riverbed is stable, the flow rate is slow, the shore is not easy to be scoured, the seabed is free of obstacles such as rock mountains or sunken ships, and there are few sunken anchors and trawlers.
2 Cables should not be laid near wharves, ferries, hydraulic structures, dredging areas and planned port building areas.
The underwater cable shall not be suspended in the water and shall be buried at the bottom. In navigable waterways and other waters that need to be protected against external mechanical force damage, the cable should be buried in a trench of appropriate depth at the bottom of the water, and should be firmly covered for protection; The burial depth of shallow water area should not be less than 0.5m, and that of deep water channel should not be less than 2m.
Crossing and overlapping of underwater cables are strictly prohibited. Adjacent cables shall be kept with sufficient safety distance, and shall meet the following requirements:
1 In the main channel, the cable spacing should not be less than 1.2 times the average maximum water depth. The distance to the bank can be reduced appropriately.
2 In the non navigable river where the flow rate does not exceed 1m/s, the distance between single core cables in the same circuit shall not be less than 0.5m, and the distance between cables in different circuits shall not be less than 5m.
3 In addition to the above situations, it shall be determined according to factors such as water flow rate and cable burial depth.
The horizontal distance between underwater cables and industrial pipelines should not be less than 50m; When restricted by conditions, it shall not be less than 15m.
For the section from underwater cable to shore, protective measures suitable for laying conditions shall be taken, and the following provisions shall be met:
1 When the shore is stable, protective pipes and trenches shall be used to lay cables. If necessary, working wells can be set for connection. The lower end of the pipe trench should be placed at least 1m below the lowest water level.
2 If the shore is not stable, it is advisable to lay in a circuitous way to reserve cables of appropriate spare length.
Eye catching warning signs shall be set on both sides of the underwater cable.
