620.21 GROUND VIBRATION LIMITS FOR CIVIL WORKS.
   (a)   Ground vibrations at locations of the following structures shall not exceed a peak particle velocity of 2.0 inches per second at any pipeline, underground utility or other structure similarly restrained underground. Blasting will not be permitted adjacent to concrete less than 10 days old unless the concrete has already attained a required strength of 3,000 psi. Shotcrete placed as initial support is exempt from the specification.
   (b)   Where the proximity of the structure to the blast precludes direct monitoring, analytical shall be used means to show conformance with these limits. This determination shall be provided to the engineer prior to blasting.
(Ord. 2005-5-4. Passed 5-3-05.)