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Rule 6.5 <br />L~ <br /> <br />SD = Scaled Distance (ft/161~~) <br />D= Distance (ft) <br />W= Maximum charge weight per delay (lbs) <br />These ground vibrations are elastic waves, meaning that the ground particles move as the <br />wave passes and quickly come to rest exactly as they were before the wave arrived. The <br />average person is quite sensitive to ground motion, and can feel the vibration at levels <br />several orders of magnitude lower than motion at damage threshold levels. Ground <br />particle motion occurring at velocities as low as 0.50 mm/s (0.02 inls) can be detected by <br />the human body. <br />Waveform -Seismic Signa3 <br />Velocity of Particle Motion measured <br />with respect to time <br />~ Peak <br />o A}dPL13llDE <br />m <br />> BASE <br />'~ -_ ~ LlNE <br />a ++ <br />1 CYCLE f <br />T <br />DURA310N <br />3-^--11N E -} <br />Particle Vibration Tinge History <br />Vibrating ground motion can be chazacterized by measuring particle displacement, <br />velocity, and vibration frequency. <br />Displacement is a measure of ground particle travel distance or directional position with <br />respect to time. Particle velocity measures the speed of the movement while acceleration <br />• is the rate of velocity change. Vibration frequency is a measure of how mane oscillations <br />a ground particle makes in each second of time. <br />ApP~ibitsA-T-APP(1180)RevBOmuary 19, 2002 <br />