Dyno42 and SignaShot: Proprietary Signature Hole Analysis Software and Technical Expertise Control Coal Mine Cast Shot Vibration
Document type: Case Study
Categories: Case Study

DYNO42 & SIGNASHOT: PROPRIETARY SIGNATURE HOLE
ANALYSIS SOFTWARE AND TECHNICAL EXPERTISE
CONTROL COAL MINE CAST SHOT VIBRATION
 The project was successful as the vibration limits were not
 PROJECT SUMMARY exceeded and the mine was able to maintain the status
 quo with regards to its cast blasting programing. The
DYNO42 & SIGNASHOT PROVIDE SIGNATURE postponement of transitioning to smaller diameter holes
HOLE ANALYSIS (SHA) TOOLS TO DETERMINE saved operational costs and efficiency. Additionally, the
OPTIMAL CAST BLAST TIMING FOR VIBRATION “business as usual” cast performance and costs resulted
 in an agreement with the pipeline owner, who had been
A cast blasting coal mine located in Indiana had begun holding out in anticipation of the mine feeling financial
to deck cast blasts and was considering a switch to a pressure, to move the pipeline removing the vibration
smaller diameter hole as the mine progressed closer to constraints on the pit. two separate two-inch-per-second (IPS) limit pipeline
risers. The objective of the project was to not only stay The results of each blast were also reviewed for adherence
under the two-inch-per-second vibration, but to do this to SignaShot prediction and compared to a scaled distance
while continuing cast blasting maintaining a single powder calculated PPV to quantify the efficacy of the software.

SignaShot could then be used on a shot-by-shot basis to
determine a predicted average PPV, as well as upper and COAL MINE VIBRATION LIMITS NEARED AS
lower bounds of PPV for the specific shot scenario. This MINE PROGRESSES TOWARDS PIPELINE
was particularly useful due to the layout of the pit to the RISERS
two pipeline risers that were each monitored by permanent The coal mine located in Indiana is a multi-seam dragline
seismographs with fixed geophone locations. SignaShot’s operation utilizing cast blasting that allows explosive
inputs and calibration process account for the increasing energy to move a percentage of the overburden to its final
or decreasing distance and orientation of the geophone to location. The 10-5/8’’ cast holes are drilled at an incline
each respective pipeline location with regards to the cast and range from 85’ to 95’ in depth. blast.

vibration, but to do this to SignaShot prediction and compared to a scaled distance
while continuing cast blasting maintaining a single powder calculated PPV to quantify the efficacy of the software. column, current hole diameter, efficient shot lengths, and
the mine’s desired timing ranges.

The DynoConsult team utilized the Dyno Nobel suite of
signature hole analysis (SHA) tools, Dyno42 and SignaShot,
in conjunction to identify a timing scheme that was optimal
for vibration but also fell within the mine’s desired timing
ranges for hole-to-hole and row-to-row timing. The project
utilized six signature holes per every other mining cut. Dyno42 would use these waveforms to analyze all desired
timing sequences and shot length scenarios for the cast
blast. These results could then be filtered down based on
peak particle velocity (PPV), frequency (Hertz, Hz), and
other attributes such as minimum delay (milliseconds,
ms). Once one or multiple timings had been proposed then
this timing scenario(s) could be simulated by SignaShot to
provide a statistical analysis of the PPV resulting in high Cast Blasting at Coal Mine in Indiana
confidence in the upper and lower bounds of the PPV. This
process would result in a selection of a timing scheme for
that area of the cut. BACKGROUND
SignaShot could then be used on a shot-by-shot basis to
determine a predicted average PPV, as well as upper and COAL MINE VIBRATION LIMITS NEARED AS
lower bounds of PPV for the specific shot scenario.

CASE STUDY

ring the project Dyno42 was used to generate a range
had started to deck for this section of the pit. of timings for each additional signature hole, and these
 results were analyzed through SignaShot. The mine would
 provide final approval upon reviewing the recommended
 timing(s). With this timing selected, then SignaShot could
 run a shot-by-shot simulation based on shot location and
 other needed inputs. The simulated PPV average and
 minimum/maximum were compared to the actual PPV
 to measure the efficacy of the software. Additionally, the
 SignaShot accuracy results were compared to the result
 of the site accepted scale distance prediction to show
 differences in the results of the two approaches.

For the 27 SignaShot simulations run for shots there
 was no exceedance of the max predicted value and
 average difference of actual vibration versus simulated of
 .00974 IPS. The deviation for the values was .165 IPS.
 For the same 27 events the site calibrated scale distance
 prediction averaged a -.388 IPS showing the equation
Pipeline Riser and Permanent Seismograph trending towards being overly conservative and potentially
 leading to premature adaption of changes to the cast blast
 design. Additionally, the scale distance prediction had
 been previously drastically exceeded contributing to the
 decision to deck some shots in the middle of the pit and
 was then exceeded again by a decked shot prior to the full
 introduction of SignaShot to the site.

CASE STUDY

The pit runs parallel to a pipeline and progressing towards
the structure. When buried, the pipeline has a state PROJECT GOALS AND RESULTS
regulated 5-inch-per-second (IPS) limit but risers, of which
there were two in proximity to the pit, are limited to 2 IPS. DYNO42 DELIVERS SUCCESSFUL TIMING &
One riser was located mid-pit with the other riser located SIGNASHOT PROVIDES CONFIDENCE NEEDED
at the end of the pit. These risers were monitored by
 The objective of the project was not only to stay under
permanent seismographs with fixed geophone orientation. the two-inch-per-second vibration, but to do this while
 continuing cast blasting, maintaining a single powder
The monitors were able to remotely report the vibration
 column, current hole diameter, efficient shot lengths, and
results. The life of mine plan anticipated negotiation
 the mine’s desired timing ranges. with owners of the pipeline to allow waiver of vibration
limits and later relocation of the pipeline. However, at the
 DynoConsult expertise along with the use of both Dyno42
time of the project, inception negotiations had ceased. and SignaShot allowed the project to meet this goal with
Due to this, the mine anticipated higher operation costs
 provided timings that allowed the mine to keep its cast
and lower efficiency as hole size would be reduced,
 blast design as-is.

his goal with
Due to this, the mine anticipated higher operation costs
 provided timings that allowed the mine to keep its cast
and lower efficiency as hole size would be reduced,
 blast design as-is. SignaShot performed so well in its
which would result in more holes and shot length being
 predicted PPV the mine ceased decking in mid-pit after
decreased. This would result in more blast delays and
 the simulations of the selected Dyno42 timing showed
lower cast performance, and other blasting parameters
 vibrations would not exceed the 2 IPS limit. would potentially need to be adjusted to ensure the 2 IPS
limit was not exceeded. The two guiding determinations
 The postponement of detrimental changes to the cast
to the mine for when to deck and change hole size were
 program contributed to the pipeline owners resuming
their site-specific scaled distance equation and trends in
 negotiations and reaching an agreement on the future of
the vibration results. An example of this is the mine had
 the pipeline
observed higher than expected peak particle velocities
(PPV) when blasting in the middle of the pit and therefore
 During the project Dyno42 was used to generate a range
had started to deck for this section of the pit. of timings for each additional signature hole, and these
 results were analyzed through SignaShot.

CASE STUDY

Processing Signature Hole Signal for SignaShot
SignaShot Predictions Outperformed Scale Distance with
a Mean Difference of ~0 IPS and Lower Deviation

n the geology in which it travels. SignaShot is an additional software tool that utilizes
Various timing sequences can then be modeled based
 statistical analysis in its simulation of delay sequences. upon this wave to find a timing scenario that targets a
 The in-depth analysis utilizes synthetic waves from Fourier
higher frequency, a lower amplitude, or both while best
 series, calibration to blast event, and statistical probability
maintaining blast performance. to drive its prediction capability. The stochastic approach
 for additional evaluation of the Dyno42 timing results
During the project Dyno42 was used to generate a range
 provides statistical confidence in the upper and lower
of timings for signature holes and these results were
 limits of the prediction values. analyzed through SignaShot.

Dyno42 utilizes the signature hole data and the Dirac
signal processing algorithm to provide timing analysis
based on amplitude (PPV in IPS), frequency (Hz), or a best
practices combination. The analyzed delay range can be
automatically set based upon industry or set to a custom
range. The design and quick results allow for a wide range
of delays for different shot configurations and monitoring
points to be analyzed. The deterministic results of this
software are determined solely by the inputs and initial
conditions.

For this project the signature hole waveform would be
 captured at both pipeline risers. Six different shot lengths
 would be analyzed using the respective waveform to
 TECHNOLOGY APPLIED each location. The excel output for these 12 scenarios
 could then be compiled and sorted to find a common
DYNO42 & SIGNASHOT SIGNATURE HOLES timing sequence that produced higher frequencies, lower
ANALYSIS (SHA) SOFTWARE amplitude, and met the mine’s desired delay ranges for
 cast performance. Dyno42 & SignaShot are proprietary software offerings
available through Dyno Nobel that facilitate signature hole
 Finding a common timing that performed well amongst
analysis (SHA) to predict and control blast vibrations. SHA
 all scenarios and to both pipeline riser locations was
is a technique in which one blasthole in the project area
 beneficial to the mine in terms of operational consistency
is detonated and the vibration results captured as points
 for the blasters on the bench. of concern. The goal is to capture a waveform free from
all influences other than the geology in which it travels. SignaShot is an additional software tool that utilizes
Various timing sequences can then be modeled based
 statistical analysis in its simulation of delay sequences.

n limits on the pipeline. This and other factors led
 to an agreement between the pipeline and mine providing
PROJECT ALLOWS CONTINUED USE OF LARGE a vibration waiver until the pipeline was relocated. DIAMETER HOLES LEADING TO OPERATIONS
COST SAVINGS AND MORE
The project delivered value to the mine on multiple levels. This included operational cost, operational efficiency,
license to operate, and long term mine strategy.

roject based upon these factors was average accessory and bulk explosive costs. The assumed
more than $100,000. pattern dimensions for a smaller hole diameter were made
 in consultation with the mine. The cost savings were
Regarding operational efficiency, being able to maintain calculated for elimination of decked holes for a length of
the same hole size and not having to reduce shot length a cut at the beginning of the project, the postponement of
(as a function of a restriction on number of holes) versus a a change in hole size for the entire length of the following
smaller hole size, decked holes, or shortened shot length cut, and the length of the next cut that had been blasted
results in greater cast and effective cast performance. The prior to the signing of a vibration waiver limit. efficiency gains can be hard to quantify as a final number

In terms of drill and blast operational cost, by continuation AUTHOR’S NOTES
of the use of the larger 10 5/8’’ diameter the number of
drill holes did not increase. An increase in drill holes would Vibration data from 3/6/2020 was omitted due to
have led to an increase in number of detonators and geophone being reset to a different orientation by vendor
boosters used and a drastic increase in drill footage. The prior to shot. mine credited SignaShot with providing the confidence
needed at the time to proceed with two additional cuts Operational costs saved calculated in “Value Added” are
in the pit with 10 5/8’’ holes. A projected cost savings for based upon an approximation of drill cost per foot and
the duration of the project based upon these factors was average accessory and bulk explosive costs. The assumed
more than $100,000. pattern dimensions for a smaller hole diameter were made
 in consultation with the mine.

Disclaimer: This case study is provided for informational purposes only. No representation or warranty is made or intended by Dyno Nobel or
its affiliates as to the applicability of any procedures to any particular situation or circumstance or as to the completeness or accuracy of any
information contained herein, and, to the full extent permitted by law, Dyno Nobel expressly disclaims any liability arising from the use of this
document or the information contained herein. User assumes sole responsibility for all results and consequences. © 2020 Dyno Nobel

CASE STUDY

For the project, SignaShot was utilized in two ways. First, due to the various impacts on cast performance and lack
if there were timing scenarios that produced similar results of empirical data for a smaller diameter hole in this pit. in Dyno42 then a SignaShot simulation of the various However, it is known cast performance did not suffer a
scenarios could provide additional insight and help on reduction in performance during the project and was
selection of the timing sequence. Secondly, SignaShot not exposed to a potential reduction through changes in
was routinely used to simulate upcoming blasts to provide the cast design due to the effectiveness of the vibration
a predictive PPV whether as a check or validation to a control timing generated through Dyno42 and SignaShot. change in shot length, etc. Lastly, it impacted the mine’s long term mine plan for this
Over the course of the project the SignaShot predicted pit. The mine had anticipated negotiation for a waiver
PPV versus the recorded PPV had an average difference and relocation of the pipeline within the mine plan. While
of.00974 IPS. These results speak not only to the negotiations with the pipeline owners were ongoing the
accuracy but also to the flexibility of the software.

the pipeline within the mine plan. While
of.00974 IPS. These results speak not only to the negotiations with the pipeline owners were ongoing the
accuracy but also to the flexibility of the software. Often mine began to forecast increased operational costs
at points of concern there are permanent seismographs anticipating an agreement would not be reached in time
with a fixed geophone orientation which can lead to issues to prevent impacts to the drill and blast program. With
with SHA due to the shot location changing in distance negotiations at an impasse, DynoConsult assisted the
and orientation to the monitoring equipment. This could customer in setting up a signature hole analysis project
require an inordinate amount of signature holes to achieve utilizing Dyno42 and SignaShot. By eliminating the area
consistent results. where holes were being decked and postponing changes
 to the cast design, the project contributed to reducing the
 negotiation leverage of the pipeline while also maintaining
 a regulatory and social license to operate by not exceeding
 VALUE ADDED vibration limits on the pipeline. This and other factors led
 to an agreement between the pipeline and mine providing
PROJECT ALLOWS CONTINUED USE OF LARGE a vibration waiver until the pipeline was relocated.