Trenches excavation shall be carried out without shoring/with light shoring/with heavy shoring depending on the stability of the ground. Light shoring/no shoring shall be used for shallow trenches in stable ground with lower ground water table. Arrangements for heavy shoring shall be submitted for the approval to the Engineer before using them.
Excavated surfaces too steep shall be protected and supported as necessary to safeguard the work and workmen, to prevent sliding or settling of the adjacent ground.
• Other support installation
The Contractor shall remove all the supporting installation once the work is finished.
Trenches shall be effectively supported including sheet piles where necessary to prevent any fall/run from any portion of the ground outside the excavation into the trench and to prevent settlement/damage to structures adjacent to the excavation.
Where battered sides shall be elected there shall be provided with stable slope (height at a slope of not steeper than one to one from point of 300mm above the pipe).
REMOVING OF TRENCH SUPPORT
Removing of trench support shall be done simultaneously with the backfilling. Lowest bracing shall be removed once completed the backfilling up to that level. So on for bracing for higher levels.
The Contractor shall be responsible for removing all the supporting systems that are used for the pipe laying process.
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