3
were conducted as a preliminary step to the formulation of
the different blast designs, varying the product densities.
The blaster-in- charge lets the product gas after loading the
hole, to attain a 15% product raise to reduce the density
from the normal 1.33 g/cc to 1 g/cc (Austin Powder, 2022
Revised).
The evaluated scenarios changed the drill pattern from
a square 10 feet x 10 feet (3 meters x 3 meters) to staggered
patterns of 10 feet x 11 feet (3 meters x 3.3 meters) and
10 feet x 12 feet (3 meters x 3.6 meters) with 4-to-5.5-inch
diameter blast holes.
METHODOLOGY
Modelling
The 3GSM BlastMetrix software is a scientific tool used
across CRH operating companies to design, model, or audit
the blasts to help implement the drill and blast continuous
improvement program. The 3D models from aerial imagery
are the efficient valuable data source for designing, docu-
menting, and quantifying surface blasts (Andreas Gaich M.
P., 2020). With this tool, we analyzed the minimum bur-
den on three-dimensional view and, more importantly, the
inter-hole distances at the designed floor plane, which has
been a key for loader diggability issues.
Explosive properties such as density, velocity of detona-
tion, energy values, and energy partitioning were calculated
for the type of explosives used. During the blast, drone
photography/videography and seismographs were used to
document the detonation to assist in developing the base
case. The post-blast muck pile was then surveyed to deter-
mine the heave results. A fragmentation analysis was also
performed.
This software modeling package deals with new meth-
ods for automatically designing surface blasts and improved
quantification of the muck pile, both together aiming at
a procedure that allows a stepwise, reproducible improve-
ment of the blasting works. The main data source is aerial
imagery from the DJI Phantom 4 Pro drone that generates
a comprehensive 3D model from image processing algo-
rithms. The following sections discuss the optimized design
techniques using this tool.
Design Process
This process includes understanding the blasting results
between both the traditional profiles and 3D modeling
minimum burden acquired. The key focus in the design
process is keeping the two main KPIs in the plan: frag-
mentation and volumes (which relate to the powder fac-
tor). Figure 1 shows the highwall face looking towards the
east, where the mine development plan is reconciled for
applying various blast design scenarios. Below case study is
representing one of the optimized case of 4 inch blast hole.
A minimum burden profile shown in Figure 2 looking
at the highwall face towards the north, and Figure 3 shows
towards the east. This geometric entity consists of a borehole
on the corners or open face, to fulfill the minimum burden
criterion at best (i.e., minimum burden equals design bur-
den) or vice versa (Andreas Gaich M. P., 2020). The soft-
ware also has an algorithm capable of aligning boreholes
Figure 1. Highwall face looking at the east
Figure 2. Minimum burden for the highwall face looking
towards the north
Figure 3. Minimum burden for the highwall face looking
towards the east
were conducted as a preliminary step to the formulation of
the different blast designs, varying the product densities.
The blaster-in- charge lets the product gas after loading the
hole, to attain a 15% product raise to reduce the density
from the normal 1.33 g/cc to 1 g/cc (Austin Powder, 2022
Revised).
The evaluated scenarios changed the drill pattern from
a square 10 feet x 10 feet (3 meters x 3 meters) to staggered
patterns of 10 feet x 11 feet (3 meters x 3.3 meters) and
10 feet x 12 feet (3 meters x 3.6 meters) with 4-to-5.5-inch
diameter blast holes.
METHODOLOGY
Modelling
The 3GSM BlastMetrix software is a scientific tool used
across CRH operating companies to design, model, or audit
the blasts to help implement the drill and blast continuous
improvement program. The 3D models from aerial imagery
are the efficient valuable data source for designing, docu-
menting, and quantifying surface blasts (Andreas Gaich M.
P., 2020). With this tool, we analyzed the minimum bur-
den on three-dimensional view and, more importantly, the
inter-hole distances at the designed floor plane, which has
been a key for loader diggability issues.
Explosive properties such as density, velocity of detona-
tion, energy values, and energy partitioning were calculated
for the type of explosives used. During the blast, drone
photography/videography and seismographs were used to
document the detonation to assist in developing the base
case. The post-blast muck pile was then surveyed to deter-
mine the heave results. A fragmentation analysis was also
performed.
This software modeling package deals with new meth-
ods for automatically designing surface blasts and improved
quantification of the muck pile, both together aiming at
a procedure that allows a stepwise, reproducible improve-
ment of the blasting works. The main data source is aerial
imagery from the DJI Phantom 4 Pro drone that generates
a comprehensive 3D model from image processing algo-
rithms. The following sections discuss the optimized design
techniques using this tool.
Design Process
This process includes understanding the blasting results
between both the traditional profiles and 3D modeling
minimum burden acquired. The key focus in the design
process is keeping the two main KPIs in the plan: frag-
mentation and volumes (which relate to the powder fac-
tor). Figure 1 shows the highwall face looking towards the
east, where the mine development plan is reconciled for
applying various blast design scenarios. Below case study is
representing one of the optimized case of 4 inch blast hole.
A minimum burden profile shown in Figure 2 looking
at the highwall face towards the north, and Figure 3 shows
towards the east. This geometric entity consists of a borehole
on the corners or open face, to fulfill the minimum burden
criterion at best (i.e., minimum burden equals design bur-
den) or vice versa (Andreas Gaich M. P., 2020). The soft-
ware also has an algorithm capable of aligning boreholes
Figure 1. Highwall face looking at the east
Figure 2. Minimum burden for the highwall face looking
towards the north
Figure 3. Minimum burden for the highwall face looking
towards the east