Laserfiche WebLink
i. <br />.. i_:.M1 <br /> <br />C~ <br />Five pipeline sections were studied by the U.S. Btrreatt of Mmes is txmj»netion with the State of <br />Indiana and AMAX Coal and its tmnsttltams in the advance of coal mine overhtrrdm blasting <br />(USBM RL 9523).' These tests were conducted tm the highwall of the Mi~thaha Mine near <br />Sullivan, Indiana sail wen desigtu~ for testing to failttte. <br />All five pipeline sections were 76 m (249 ft) long. Fora sections were welded steel pipe and one <br />section was PVC. The pipeline sections were laid parallel to one another, 3 m (9.8 ft) apart, with <br />1 m (3.3 ft) depths of burial. Thry were buried in a clay sm1 Each pipeline had threo uprights <br />for pressurization end gage access. Following is a summary of the pipeline attabtttes: <br />o~taae Diaoeter, <br />~ Cm) wau'fhielmeaa, <br />tmr4 Can) . ~ Muerial Ape <br />. Material Type <br />Stee1• <br />16.8, (6,6) 4.78, (.IBB) l3aa Uasd X-42 <br />324, (12.8) 6.35, (.Z50) Go Used tirade B <br />324, (12.8) 6.35, (.230) Crag New X-42 <br />50-& (20.0) 6.63, (.261) water Used X 56 <br />pVC: <br />Steil Pipelines: iaittal preeaaiatiort 62 MPa (900 pal <br />PVC PipoLne: Initial pceauti>mon 0.62 MPs (90 pad. <br />The pipelines evere monitored for vibration, strain, aatd pressure for a period of 6 momhs while <br />production advanced up to a point 15 m (49 ft) away. 29 productions bleats were measured. <br />The blasts used maximum charge weighs per delay of up to 950118 (2090 pounds) in 31 cm <br />(12.25 inch) diameter holes. <br />Following the production blasts, a single row of four blast holes was drilled between the <br />pipelines to complete the destructive test. The explosive charge was below the popes at 5 w 6 m <br />(16.4 to 19.7 ft) distances. The vibration level meastaed was greater than 900 mm/s (35.43 ids), <br />however, this was non-elastic response. The result of the destructive teat on each pipeline is as <br />follows: 1) 16.8 cm (6.6 in) diameter steel pipe -severely hero but unbroken, 2) new 32.4 tmi <br />(12.8 in) tiiame;ter steel pipe -bowed, but unbroken, 3) used 32.4 cm (12.8 in) diameter steel <br />pipe -cleanly broken at the risers, 4) water 5lled 50.8 tart (20.0 in) diameter steel pipe - <br />uplifttxl, parted, fell back down, and 5) 22 cm (8.6 in) diameter PVC pipe -came apart at O- <br />rings,but unbroken <br />The results of the closest production blast (15 m (49.2 R) distant from the closest pipeline) <br />resulted in a 635 cords (25.00 ids) measuremem at the surface and 234 to 274 mm/s (9.21 to <br />' Sisltin0. D.E., M.S. Stagg, J.E. Wiegand, and D.L Schulz Surface Mice BLsting Neer Preswrized <br />Ttaoamisrion Pipelaes. U.S. Btaew ofbfinea, Report of Tavot>g.tpoaa 9523. 1994. S I pp. <br />• <br />