Excavation of Trenches. Before excavation of trenches the route should be marked for trenching. Care should be taken to see that the route of the trench to excavate is reasonably straight avoiding the existing underground service. • The Vendor should take trial pits to locate the underground services before commencement of actual trenching. These trial pits shall be 30 cms. wide, 120 cms. deep and 120 cms. Long at right angles to the proposed trench at an interval of 20 to 50 Mtrs along the proposed cable route. If a slab is encountered, the same may be removed and trial pits may be made. • In city areas, the trench will normally follow the footpath or the road except where it may have to come to the edge of carriage way or cutting across roads with the specific permission from the concerned authorities maintaining the road (such permission shall be obtained by the Vendor). Outside the city limits, the trench will normally follow the boundary of the roadside land. However, where the roadside land is full of xxxxxx pits or when the cables have to cross culverts / bridges or streams, the trench may come closer to the road edge or in some cases, over the embankment or shoulder of the road (Permission for such deviations for cutting the embankment as well as shoulder of the roads shall be obtained by the Vendor). • The alignment of the trench will be decided by Engineer‐In‐Charge or by TPA. Once the alignment is marked, no deviation from the alignment is permissible except with the approval of Engineer‐In‐Charge or TPA. While marking the alignment only the center line will be marked and the Vendor shall set out all other works to ensure that, the excavated trench is as straight as possible. The Vendor shall provide all necessary assistance and labour, at his own cost for marking the alignment. Vendor shall remove all bushes, undergrowth, stumps, rocks and other obstacles to facilitate marking the center line without any extra charges. It is to be ensured that minimum amount of bushes and shrubs shall be removed to clear the way and the Vendor shall give all consideration to the preservation of the trees. The line‐up of the trench must be such that cables shall be laid in a straight line except at locations where it has to necessarily take a bend because of change in the alignment or gradient of the trench.
Excavation of Trenches along the roads (which are carpeted end to end) The excavation of trenches along the roads which are carpeted from end to end including dismantling of' asphalt, concrete and WBM shall be done up to a depth such that the top of the cable is 1.0 M below the normal ground level. The excavation along the roads shall be done manually. The Vendor shall have to provide shoring wherever necessary, in case the depth of trench is more than one meter. It is expected that the other services may be present below the roads, therefore, extra care need to be exercised while excavation of trenches.
