GAIL (India) Limited

7If required to protect the sides of pits and trenches, timber shoring and strutting shall be erected. Thetimbering shall be closed or open depending on the nature of the soil and work, and arrangement oftimbering including sizes and spacing of members used shall be as approved by the Consultant. NO extracharges shall be admissible on this account.The bottoms of all excavation shall be trimmed and leveled in accordance with drawings / directions ofthe Consultant / Engineer-in-charge. The bottoms of all excavation shall be rammed and wetted beforedeposition of concrete. The contractors shall report to the Consultant / Engineer-in-charge when theexcavation is ready to receive concrete. NO concrete shall be placed in foundations until the contractorhas obtained the approval of Consultant / Engineer-in-charge.1.6.2 PROTECTIONAll foundation trenches and similar excavations shall be strong, fenced and marked with red lights at nightfor watchmen to avoid accidents.Adequate protective measures shall be taken to see that the excavation does not affect or damageadjoining structures. All measures required for the safety of the excavation, the people working in andnear the foundation trenches, property and the people in the vicinity shall be taken can by the Contractorat his own cost, being entirely responsible for any injury and damage to property caused by his negligenceor accident due to his construction operations.1.6.3 STACKING OF EXCAVATED MATERIALS:Work for excavation shall include sorting out of useful materials and stacking them on site as directed.Materials suitable and useful for back-filling, plinth, filling, leveling of the plot or other use shall bestacked convenient places, but not in such a way as to obstruct free movement of men, equipment andvehicles or encroach on the area required for constructional purposes.1.7 BACKFILLING1.7.1 Earth obtained from excavation (or approved earth brought from out side for which no extra paymentshall be made) shall be filled in layers as described in 1.7.3 around the foundations and under floors, Incase extra earth used for filling is required under floors, plinth protection including sit outs, courtyards,the contractor will do at their own cost. The lump sum offer shall be deemed to include the earth filingrequired under floors and plinth protection with plinth height shown in Drawing above the bottom offoundation concrete and finished courtyard level shown in Drawing below D PC /coping level of the mainbuilding.1.7.2 QUALITY OF FILLFill shall be of well compacted, well graded earth or sand and shall be free from tree stumps, organicmatter, seed and peat etc Where earth or sand from source other than excavation at site is used, the qualityof such earth or sand shall be the same as that obtained from excavation at site, or superior to it. Fine sandfor filling is River Sand. Black cotton soil shall not be used for back filling or plinth filling.1.7.3 COMPACTIONThe fill shall be spread in layers not exceeding 20 cm thick and each layer shall be watered andthoroughly consolidated by suitable mechanical rollers, rammers, vibrators or other approved plant orsystem of compaction. The fill material shall be pulverized before depositing in place. An optimummoisture content shall be maintained for the filled materials. Compaction shall be done so as to achieve adry density of not less than 90% of the maximum density obtained at optimum moisture content, exceptfor the upper 20 cm layer which shall be compacted to a density of not less than 95% of the maximumdensity.In order that the fill shall be reasonably uniform through out, the material shall be dumped in place inapproximately horizontal layers “Edge dumping”, a process by which the materials is pushed off edge ofthe fill and allowed to roll down the slope shall not be carried out. If there is traffic over the fill duringconstruction, either by construction equipment or otherwise, it should be routed to make the compactionas uniform load shall be maintained and also care shall be taken to prevent any wedging action.