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4.08 Use of Exploaives, (continued) <br />• close to the pipe line blasting could safely be accoplishsd. <br />Lewicki and Associates engaged the services of Geosonics, <br />Inc,, a fir^ with 18 years of experience in providing specific <br />blast and vibration engineering work to the mining industry, for <br />expert assistance with the problems. <br />The results of the study is herewith submitted in a 43 page <br />document titled 'Blasting Plan Variance Ri~rock Mins•. The <br />study implies that welded steel gas pips lines constructed after <br />1949 are safe at particle velocities of 10 inches per second or <br />more, and a safe particle velocity arrived at by Geosonics, on <br />information supplied by Lewicki, is 9 inches per second with a <br />safety factor of 2. Consequently a 6.5 inches per second <br />velocity will be used by Ri~rock Coal in all of their blast <br />• calculations within 500 feet of the pips line. <br />Exhibit QO shows the powder chargs(AMFO) necessary between <br />Bas delays to achieve a particle velocity of 6.5 inches per <br />second at distances ranging from 500 feet to 50 fast of the pips <br />line. <br />Lewicki and Associates suggests a monitoring plan to bs <br />followed for the first and subsequent blasts through the use of <br />a Everlert II blasting seisaograph a~anufactursd by Vibra-tech <br />Engineers,Inc., and located in Mest~inistsr, Colorado. Ths <br />specifications of the instrument are in the report. All of the <br />blasts monitored by the seis~ogroaph will bs recorded and stored <br />on a floppy disk for psr~ansnt storage. Ths peak velocity in <br />• 3 <br />