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Janice Lynn Bennett - 81422.PDF Page 14 <br />Blasts <br />10.00 <br />1.00 <br />y 010 <br />a. <br />0 01 <br />0 00 <br />1 00 <br />H isto rical N YC Vibration D ata Plot <br />10 00 <br />100 00 <br />Scaled Distance <br />1000.00 <br />Carnegie <br />■ Con -Ed <br />Hunter <br />Figure 3.4 — Histo rical N YC Scaled Distance —PP V Data from Blasting at Carnegie Hall, the Con - Edison Shaft at <br />36' Street and I" Avenue and foundation blasting at H unter College at between 38' and 39' Streets (NOTE: the 95% <br />curve means that 95 percent of the t 'me, predicted values will be lower than the value calculated). <br />olorado <br />95% CurPPV= 46.6(D /Wo 5) -i i4 <br />When site - specific historical data is not . . flab e, the K fact r, value can be estimated based on <br />physical rock properties and degree of blast co ement. From the author's past experience, for <br />blasts in the Fort Hayes Limestone at the Red Rock s - a prediction equation with a K factor of <br />240 can be used to predict vibration intensities (PPV) at va s locations of concern. The <br />resulting prediction equation, which is used in the site - specific ev. .tions in Section 4 of this <br />report, is shown Equation 3.3 below. <br />Equation 3.3 <br />Colorado regulations, enforced by the Division of Labor, restrict vibration intensities to a range of <br />0.75 to 2.0 in /s depending on distance. As shown later in the vibration prediction calculations for <br />the Red Rock site, vibration intensities will be far below levels that could cause any form of <br />damage. <br />In addition to concerns about vibration damage, under certain conditions, humans and animals can <br />be startled or annoyed by blast - induced ground vibration. Research has also shown that the human <br />response to transient vibration - -like those caused by blasting - -varies depending on exposure time <br />and the intensity of the motion. Response curves defining how humans respond to transient <br />vibrations based on these variables are shown in Figure 3.5. <br />1 REVEY Associates, Inc. <br />Page 11 July 2002 <br />