GAIL (India) Limited

82a) The contractor shall at all times during the progress of the work keep the trenches and excavations freefrom water which shall be disposed of by him in the manner as will neither cause injury to the publichealth nor to the public or private property nor the work completed or in progress nor to the surface of anyroads or streets, nor cause any interference with the use of the same by the public.b) if any excavation is carried out at any point or points to a greater width than specified cross section ofthe sewer with its envelope, the full width of the trench shall be filled with concrete by the contractor athis own expense and charges to the requirements of the Consultant4.1.11 WIDTH OF TRENCHESThe Consultant shall have power by giving an order in writing to the contractor to increase the maximumwidth in respect of which payment will be allowed for excavation in trenches for various classes of sewer,manholes and other works in certain lengths to be specifically laid down by him where on account of badground or other unusual conditions, he considers that such increased widths are necessary in view of thesite conditions.4.1.12 RECOMMENDED WIDTH OF TRENCHES at the bottom of the trench are as follows:-100 mm dia pipe 55 cms150 mm dia pipe 55 cms225 - 250 mm dia pipe 60 cms300 mm dia pipe 75 cmsMaximum width of the bed concrete shall also be as above. No additional payment is admissible forwidths greater than specified.4.2 SALT GLAZED STONEWARE PIPESStoneware pipes shall be of first class quality salt glazed and free from rough texture inside and outsideand straight. All pipes shall have the manufacturers names marked on it and shall comply to IS : 651 -1971.I) LAYING AND JOINTING OF STONEWARE SALT GLAZED PIPESa) Pipes are liable to be damaged in transit and not with standing tests that may have been made beforedispatching pipe shall be examined carefully on arrival at site. Each pipe shall be rung with a woodenhammer or mallet and those that did not ring true and clear shall be rejected. Sound pipes shall becarefully stacked to prevent damage.b) The pipes shall be laid down with sockets leading uphill and should rest on solid and even foundations forthe full length of the barrel. Socket holes shall be formed in the foundation sufficiently deep to allow thepipe jointer room to work right round the pipe and as short as practicable to admit the socket and allowthe joints to be made.c) Where pipes are not bedded in concrete the trench bottom shall be left slightly high and carefullybottomed up as pipe laying process, so that the pipe barrels rest on firm ground If excavation has beencarried too low it shall be made up with cement concrete at the contractor’s cost and chargesd) If the bottom of the trench consists of rock of very hard ground that cannot be easily excavated to asmooth surface the pipes shall be laid on cement concrete bed to ensure even bearingII) JOINTING OF PIPESa) Tarred gaskin shall first be wrapped round the spigot of each pipe and the spigot shall then be placed intothe socket of the pipe previously laid, the pipe shall then be adjusted and fixed in its correct positions andthe gasking caulked tightly home so as to fill not more than on quarter of the total length of the socketb) The remainder of the socket shall be filled with stiff mix of cement mortar (1 cement: 1 clear sharpwashed sand) When the socket is filled, a fillet should be formed round the joint with a trowel forming anangle of 45 degrees with the barrel of the pipe. The mortar shall be mixed as needed for immediate useand no mortar shall be beaten up and used after it has begun to set.c) After the joint has been made, any extraneous material shall be removed from inside of the joint with asuitable scraper or badgar. The newly made joints shall be protected until set from the sun, drying winds,rains or dust. Sacking or other materialist which can keep damp shall be used. The joints shall be exposed