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FLYROCKFLYROCKFlyrock is the propelling rock from the blast area.
Leading cause of fatalities and equipment damage
CORRECTION OF IDENTIFIED CAUSES CAN SOLVE FLYROCK PROBLEMS
FLYROCKS OCCUR WHERE ENERGY IS VENTED INTO ATMOSPHERE AND PROPELS ROCKS
WHERE BURDEN AND STEMMING IS TOO SMALL OR HOLES ARE INITIATED OUT OF SEQUENCE
DRILLING INACCURACY
OVERCHARGING
GEOLOGICAL CONDITIONS
SYMPATHETIC DETONATION
COLLARING TOO NEAR TOP OF THE FACE IN HIGH BENCH OR HIGHLY INCLINED FACE
LARGE BURDEN & TOP PRIMING CAUSES FLYROCK
GEOLOGICAL CONDITIONS
Open joints, mud seams and cavities may result in escape of gases and also blasting nuisances.
DRILLING INACCURACY CAUSES INSUFFICIENT BURDEN RESULTING IN
FLYROCK
REMOVAL OF TOE USING SHORTHOLES CAN CAUSE EXCESSIVE FLYROCK
FAULTY DELAY TIMING AND INITIATION SEQUENCE
Re-enactment of where the operator's body was found after the accident
MEASURES TO CONTROL FLYROCK DAMAGE
1. Proper blast design
2. Bench height, borehole diameter, hole
inclination, burden and spacing, charge
distribution in holes, stemming, initiation
sequence and timing
3. Site control during blasting
4. More experienced drilling/blasting crew
5. More effective communication
6. Covering
7. Miscellaneous measures loose stone, toe
holes
COVERING WITH WIRE NET
PROPER STEMMING TO CONTROL FLYROCK