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Blaspa
includes simulators which make it possible to evaluate
the flyrock for a given blast method in a given rock.
A simulation calculates the range and altitude of each
fragment of rock projected from the free surfaces of
the rock mass being blasted, and informs the user of
the maximum values of these ranges and altitudes.
There are three simulators which deal with a bench
blast, and one simulator which deals with a blast to
open a cut (e. g. to blast a ramp, or a tunnel round).
A simulation
calculates the range and altitude of each fragment of
rock projected from the top free face of the bench and
from the vertical free face of the bench, and informs
the user of the maximum values of these ranges and
altitudes. The user can obtain these maximum values
for any one of three cases, as follows: (1) the front
row of the bench (simulator called Maximum Flyrock
from Top and Face); (2) a back row of the bench
(simulator called Maximum Flyrock from Back Row); (3)
the vertical face of the front row, the top of the
bench being covered with a net to stop flyrock
(simulator called Maximum Flyrock from Face Only-Net
on Top). For more information on any one of these
simulators, click according to your choice:
-
Maximum Flyrock from
Top and Face
-
Maximum Flyrock from
Back Row
-
Maximum Flyrock from
Face Only (Net on Top)
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This simulator (Flyrock
Maximum Open Cut) calculates the range and altitude of
each fragment of rock projected from the horizontal
free face around the top of a vertical blast hole
during an open cut blast, and informs the user of the
maximum values of these ranges and altitudes. The
user can obtain these maximum ranges and altitudes for
a ‘plug’ hole, or for a hole further from the center
of the initiation.
This simulator is
useful to evaluate the risk of hazardous flyrock
during the excavation of a ramp, or if during a bench
blast the horizontal movement of the rock is
inadequate to prevent excessive upward swell of the
rock of a back row of the bench (Note: see the other
simulators explained below to learn how to remedy the
problem of inadequate horizontal rock movement to
prevent excessive upward swell of the rock of a back
row of the bench). For more information on this
simulator, click:
Note :
The simulators <
Flyrock Maximum Bench> and <Flyrock Maximum Open Cut>
do not simulate a ‘canon’ type rock projection, i. e.
one where the explosion gases push directly and in
concentrated fashion on a single slab of rock. A
‘canon’ type rock projection is exceedingly rare; it
can be simulated on request, if the detailed structure
of the open joints in the rock mass is known. The
person responsible for the blasting must avoid a
‘canon’ type rock projection by recognizing the joint
conditions likely to create such projections. |
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