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Rule QS <br />• Abhreviaticins: <br />SN =Shear wave., horizt7ritai <br />SV --== Shear wave, vertical <br />FZ = Rayiei~h wave <br />F = Cc~mpressinnal wave <br />y <br />~~~r~S. z •iR <br />:y P. $ <br />V ~ ~~ ~~ CS <br />S hpt tir ing <br />`'~~ aoint <br />~~ <br />Vi6ratinn t~,'a.ves <br />~S <br />:.r,- <br />P <br />Seismic waves decay with distance as they travel through the surrounding azeas. These <br />waves have different forms, such as body and surface waves. Their characteristics will <br />vary somewhat with changes in the local geology, but the rate at which they dissipate is <br />reasonably consistent, and allows controlled blasting operations by means of <br />relationships between distance and the explosive charge quantities. Each time the <br />distance is doubled, the vibration intensity drops to about 1l3rd of its former value. The <br />consistency of ground motion attenuation is supported by research done by the U.S. <br />Bureau of Mines (Nichols et al., 1979). The researchers found that under widely varying <br />conditions, if a sealed distance of 50-ft/Ib112 is used to limit charge weights, it is highly <br />unlikely that ground motion would cause any damage. For the purposes of ground <br />vibration ,assessments, scaled distance (SD) is distance from the blast divided by the <br />squaze root of the maximum charge weight per delay. The log-log lineaz realationship <br />between scaled distance and predicted peak particle velocity (ppv) is shown below: <br />ppv = K(SD)"' and SD=DJ~W <br />Where: ppv = Peak Particle Velocity (inchlsec.) <br />K and M= Site Attenuation Constants <br />AppExhibi~sA-T-APPQ ISO)Rev817enoary 17, 2002 5 <br />