. Engineering and Contracting . the seal was perfected the pumps were startedand cinders were dropped in small quantities down the out-side of the sheeting. These cinders were drawn into anysmall leak that developed either in the sheeting or in the seal was then tested out for some time before anv mud (79) 331 Eiif/iiiccriiH/ (Uiii (niiiiacliiip for Mdicli :>. 1!>J0. was banked around the dam. and on the dam just dewatered?, nead of about 15 ft. was secured without any banking. When the pumps had produced sufficient head on the damthe diver made an examination of tlie seal and,
. Engineering and Contracting . the seal was perfected the pumps were startedand cinders were dropped in small quantities down the out-side of the sheeting. These cinders were drawn into anysmall leak that developed either in the sheeting or in the seal was then tested out for some time before anv mud (79) 331 Eiif/iiiccriiH/ (Uiii (niiiiacliiip for Mdicli :>. 1!>J0. was banked around the dam. and on the dam just dewatered?, nead of about 15 ft. was secured without any banking. When the pumps had produced sufficient head on the damthe diver made an examination of tlie seal and, at the sametime, an examination w-as made by the use of a current-meterinside the dam to detect the location of leaks. These leaksare usually caused by sand or gravel deposits in rock seams,and may extend far out from the dam. The hardest leaks todetect are bottom leaks. So far they have given no trouble inthese dams, but there is kept on hand a compressed-air grout-ing machine ready to meet such a condition should it ?-Zaii^ ^RM^?^^Jil»^/ Bottom of Pier 4, Showing Rock Foundation. After the test of the seal, a mud bank from 6 to 10 ft. highwas placed around the dams. The pumps used were two pulsometers and one Emersonsteam pump. The Emerson pump has a capacity of 2,000 minute, one pulsometer 2,200 gal. and the second 750 minute. The steam for these pumps is supplied from portable boilers, mounted upon a scow. Three dams have already been placed and pumped shortest time required to dewater a dam was in the caseof No. 3, which was eleven days from the time the pumpswere started. No. 1 dam required four weeks and No. 4 re-quired 6 weeks. Immediately after the dams had been dewatered, formswere placed 2 ft. inside the lower wales, the rock thoroughly —Sheefino Slnnfre^ of ctn<Jers 6t m<jcf. Says fij/ed rtith sanef.
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisherchicago, bookyear19
