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Rule 6. SD (@ 2,000 ft) = 2,000 ft / 360)~Z = 258 fdlb)~2 At this scaled distance, using conservative response constants in the vibration prediction formula, the ground motion at the nearest structure would be around .042 in/sec. ppv (@2,000 ft) = 300(258)~1~6 = .042 in/sec. The intensity of this motion is approximately 12 times slower than the 0.5 in/sec-damage- threshold limit. Since all other private property is located at greater distances than the Blake Ranch, vibration intensities will further attenuate to values less than .042 in/sec at the more distant structures; therefore, since blast induced ground motion at nearby structures will be an order of magnitude lower than the threshold of damage, Rio Grande believes that the Red Rock Limestone Mine will cause no vibration damage to adjacent property. Potential for Damage to Buried Utility Lines When explosive charges detonate in rock, most of the energy is used to break and displace the blasted burden of rock between the charge and the nearest free face; however, other energy is released in the form of ground vibration, air overpressure (concussion), elastic strain waves and high-pressure gas pulses. When blasting occurs . very close to buried utility tines (within about 10 ft), damage can occur in the line lies within ground that is physically ruptured by the blast. Crushing usually occurs in the rock very neaz the charge. The extent of this compressive and shear failure zone is usually limited to one or two chazge radii. Beyond the plastic crushing zone, the rock or ground is temporarily deformed by the elastic strain waves. For some distance, tangential strain intensity exceeds the rock's strength and new fractures are created. The magnitude of strain wave energy and induced particle motion decreases as distance from the chazge increases. Rock damage is a result of the induced strain, which is generally proportional to the particle velocity. AppExhibitsA-T-APP(I180)RevB/ranuary 17,2002 (~