Z1ZZ 2010
Analysis of Effect on Vibration and Air Blast 
in Rock Quarrying
Senadeera SMADSI, Erangika MD, Herath MHBCW, 
Wickramasmghe WIUS, *Chaminda SP and Dharmarathna PGR
Corresponding author - spcchaminda@yahoo.com
Blasting induced ground vibration occurring in the quarries has 
ecome a serious environmental issue in Sri Lanka. To achieve high production 
targets the number of blasts has increased in the quarries and, therefore, mitigate 
measures to minimize the detrimental effects of the vibrations have to be identified. 
This research project on rock blasting was carried out to design a suitable indicating 
system to predict the ground vibrations and air blasts. In order to assess the 
variation of intensity of the ground vibration and the air blast over pressure, ground 
vibrations and air blasts results from two different types of explosives on different 
types of rocks were monitored. Statistical analysis of the data sets found a high level 
of confidence on the best fitting empirical relationship between peak particle 
velocity and scaled distance. By that two site-specific factors were established. A 
comparison of the analytical work revealed that the level of ground vibration varies 
significantly with the changing of charge weight per delay, explosive type, rock type 
and the distance from blasting point to monitoring point.
Key Words: Air Blast Over Pressure (ABOP), Geographic Positioning system (GPS), 
Peak Particle Velocity (PPV), Scaled distance (SD).
Abstract:
Introduction1.
The relationship between PPV and the 
scaled distance is well known over a 
long period of time 
relationship has been proven for 
selected quarries and quarry factors 
have been established to predict 
ground vibration and air blast at any 
distance.
In reality, ground vibration measured 
at a location is influenced by a number 
of controllable parameters, such as 
blast geometry, charging patterns,
explosive
and the
initiation sequence,
characteristics and delay timing while 
others like rock properties, weather 
conditions are not under control.
SP chaminda, B.Sc.Eng.(Hons) Moratuwa, 
AMIE(SL),
Department of Earth Resources Engineering, 
University of Moratuwa.
PGR Dharmarathna BA.Sc. (Hons) (S.L), 
M.Sc. (New Castle), Plt.D. (Leeds), C.Eng. 
(U.K), F.l.M.M. (U.K), F.l.E. (S.L), F.G.A. 
(U.K), F.G.G. (Ger.), Senior prefacer in 
Department of Earth Resources Engineering, 
University of Moratuwa.
SMADSI Senadeera, MD Erangika, MHBCW 
Herath, WIUS Wickramasinghe, final year 
undergraduate students of Department of Earth 
Resources Engineering.
Rock mass properties such as joints, 
fractures, and bedding planes 
causes of amplification at the vibration 
and air blast. The prediction of ground 
vibration components has a great 
importance in the minimization of 
several environmental issues. In this
designed to
M.Sc(AlT), Lecturer inare
was
ABOP for well
research, a system 
predict the GV or 
controlled blasts at a pabular
blast,
unt of explosive is used.
thefromdistance 
particular amo
33
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(2)ABOP = a SD -bThe investigation of the ground 
vibration was carried out at a quarry 
of Mathugama and two other locations
Transport
PPV - Peak Particle Velocity in mm/s, 
ABOP- Air Blast Over Pressure, SD - 
Scaled Distance in m/kg-1/2, a & b 
constants (commonly known as 
Quarry Factors)
Scale Distance is defined as,
For Ground Vibration,
Southern
Development Project.
This research project was carried out 
to understand the sophisticated 
principals of . rock blasting, modem 
blast technology with respect to site 
conditions and the control of its 
environmental impacts.
theat
are
(3)SD= D/ (W)'h
2. Methodology
2.1 Field work and Data
Collection
For Air Blast Over Pressure,
(4)SD= D/ (W) V3
In field work rock type, state of the • 
rock, joint pattern and slope was 
identified. Then the borehole pattern, 
borehole parameters and explosive 
details such as type of explosive 
(Emulsion, Dynamite and ANFO), 
amount of explosives used and the 
number of electric detonators used 
were recorded and sketched on site 
map. Location of the blast and the 
location of the monitoring points were 
also noted on the map. Locations at 
the monitoring points were in parallel 
and perpendicular with respect to the 
joint pattern.
D - Distance from Charge in m, W- 
Maximum charge weight per delay in
kg
Equation (1) and (2) could also be 
written as follows,
log (PPV) = - b log (SD) + log (a)....(5)
Results3.
The series of monitored data was 
analyzed with the aid of "Minitab 15" 
which provided complete data 
analysis environment with a high
The coordinates of the blasting points 
and the location of measuring points 
were taken by using GPS Receiver. 
The measurements of GV and ABOP 
were taken with aid of blastmates.
2.2 Data 
Analyzing
The resultant "Ground Vibration (in 
terms of Peak Particle velocity - PPV)" 
has been commonly assessed using the 
following formula.
PPV - a SDb
Preparation and
accuracy. The results derived from the 
graphs were given in the following 
tables.
Figure 1: Scatter plot of log (PPV) Vs 
log (SD)0)
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Best regression fit for vibration,
The Comparison of GV in all three 
Quarries with respect to the distance 
be graphically represented asLog (PPV) = 2.033 -1.051 log (SD)
PPV = 107.89 (SD)-i-05i
Table 1: Site factors for the GV
can
follows.
highway 02 
highway 01
Location ba
Hyundai 107.89 -1.051
46+900-47+400 252.35 -1.205 . 0 ;
oooooooooooo^'irfocooi-'j-roco©
49+200-49+470 1.721 -0.199 Distinct (m)
Figure: 3 Comparisons between PPV 
and DistanceFor the Air Blast Over Pressure,
Discussion
The results of highway shows higher 
value for GV and less value for air 
blast over pressure than that of the 
quarry. The reason for this may be, 
that the energy dissipate along the 
joint easily converts to gas pressure 
pulse. This does not take place when 
the wave moving in the perpendicular 
direction of joint strike. The reason for 
variation of results from the quarry to 
highway is due to the type of 
explosive used, safety aspects, 
elevation, rock type and the size of the 
free face.
The reasons for the selecting these 
formula is as it involve three 
important variables, namely ground 
vibration or air blast over pressure 
with distance and explosives. After 
deriving the site factors, maximum 
charge per delay can be calculated 
with respect to a given distance and 
also, the minimum distance that a 
residence can be established for given 
weight of explosive per delay.
The propagation of the shock wave 
depends on the properties of the 
medium and the gas release pulse
4.
Figure 2: Scatter plot of log (ABOP) 
Vs log (SD)
Best regression fit for Air Blast Over 
Pressure,
Logio (PPV) = 2.236 - 0.085 log (SD) 
ABOP = 172.19(SD)
Table 2: Site Factors for the ABOP
-0.085
bLocation a
-0.085172.19Hyundai
-0.093176.2046+900-47+400
-0.014119.1249+200-49+470
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The test blast results for air blast over 
have reflected similar values, 
resulted from clearance of
depends on the nature of the joints 
and other rock mass properties.
made in the course of
pressure 
This was
face between measured and blast 
The vibration value of the
Assumptions
project work were as follows.
• The property of rock mass 
constant for each blast.
• The type of soil surrounding the 
quarry was the same.
• This carried out under same
point.
always between the twowas quarry
vibration values of the highway. This 
could probably be due to the variation 
in compressive strength of the rocks. 
In addition type of explosive used also 
would have been a reason for the 
above difference. The air blast of the 
higher than that of the
weather conditions.
• The explosive type, delay type, 
stemming and the charging 
procedure was same for the each 
blast.
quarry was 
Southern Transport Development 
Project. This may be possibly due to 
the use of air blast and flyrock 
controlling methods, such as use of 
covers, sand bags, and etc in southern 
Transport development Project.
Some errors can occur during data 
collection which could affect the final 
result of the analysis. The bench to be 
blasted varied for each blast and three 
or four benches were employed with 
different angles. The direction of blast 
propagation was different according to 
the delay pattern. Variations in 
weather conditions and wind direction 
specially affected air blast over 
pressure. The soil profile variation can 
be seen with dumping of soil 
overburden around the quarry.
Acknowledgement
Our sincerely thanks go to Department 
staff of ERE for the success of this 
project. Special thank goes to Mr. D.M. 
Wijepala, Consultant Engineer of 
Hyundai Quarry, Mathugama and 
Mining engineer for the arrangement 
of site visits. We would like to extend 
our thanks to GSMB technical services 
for helping us during data collection.Conclusion
It was observed that highest value of 
ground vibration recorded was at the 
point along joint and the lowest 
that of perpendicular to the joint 
plane. The values for the air blast 
pressure show opposite results, that of 
the ground vibration.
Sometimes back side of the blasting 
location showed abnormal changes in 
monitoring. And according to the test 
blast which was carried out at the 
quarry site illustrated 
variation between measured 
mathematical value. The reason for the 
above observation could be the 
profile and/or the morphological 
differences between the blast point 
and the measured point.
5.
References
Balkema A.A, Rotterdam (1995), Drilling 
and Blasting of Rocks, p. 333 - 370.
Roy fitzgerald Nocholson, Determination of 
vibrations using peak particle velocity at 
Bengal quarry, in st. Ann Jamaica, Lulea 
University of technology.
S. M. F. Hossaini, G. C. Sen , (2006), A study 
of the influence of different blasting modes 
And explosive types on ground vibrations. 
Vol. 30, No. B3.
http://ro. uow.edu. au/coal/62,
22nd March 2010
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