2010 Construction and Material Specifications - Ohio Department of ...

208.09
During the 5-minute delay, the blaster is responsible for going into the shot
area and checking all the holes to make sure that they have detonated. If any holes
have not fired, the blaster shall handle these misfires before others enter the work
area.
Halt the blasting operations if the methods being employed result in the
required slopes not being in a stable condition or the safety and convenience of the
traveling public is jeopardized.
D. Misfire Handling Procedures. If a visual inspection indicates that complete
detonation of all charges did not take place, proceed as follows:
1. If the system was energized and no charges fired for electric systems,
test the lead wire continuity before inspection of the remainder of the blast. For
nonelectric systems, check the lead in or tube to make sure that detonation has
entered the blast area.
2. If an inspection of the electrical trunkline or lead in tubing-line
indicates that there is a break in the line or if the tubing did not fire, repair the
system and refire the blast. If the inspection indicates that the trunkline has fired,
and misfired charges remain, the blaster shall do the following:
problem.
a. Exclude all employees except those necessary to rectify the
b. Close traffic, if a premature explosion could be a hazard to traffic
on nearby roads.
c. Correct the misfire in a safe manner. If the misfire poses a
problem that the blaster cannot safely correct, the Contractor shall call a consultant
or an explosive company representative skilled in the art of correcting misfires to
rectify the problem.
208.09 Presplitting. Perform all presplitting, including that carried out in
conjunction with the blasting test section requirements of 208.07, according to the
following requirements:
A. Completely remove all overburden soil and loose or decomposed rock along
the top of the excavation for a distance of at least 30 feet (9 m) beyond the end of
the production hole drilling limits, or to the end of the cut, before drilling the
presplitting holes.
B. Remove potentially dangerous boulders or other material located beyond the
excavation limits.
C. Drill the presplit holes 3 ± 1 inch (75 ± 25 mm) in diameter.
D. Control the drilling operations by using proper equipment and technique to
ensure that no hole deviates from the plane of the planned slope by more than 12
inches (300 mm) either parallel or normal to the slope.
E. Extend presplit holes a minimum of 30 feet (9 m) beyond the limits of the
production holes to be detonated, or to the end of the cut as applicable.
F. Drill the presplit holes for any individual lift to a vertical depth of less than
or equal to 30 feet (9 m). Demonstrate that the blast can stay within the above
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