ABSTRACT
Langefors and Kihlström, 1978 c
crack-, fracture-or fissure propagation velocity and fracture growth velocity (m/s)
* c d velocity of detonation (m/s)
confined velocity of detonation (m/s) c
non-ideal detonation velocity (m/s) c
dssteady state velocity of detonation (m/s) c
hydraulic conductivity or hydraulic permeability (m/s) * c
P-wave-, sonic-or longitudinal wave velocity (m/s) c
P-wave velocity measured in the laboratory often in drill cores (m/s) c
Po P-wave velocity in homogeneous material free of prestresses and without natural physical discontinuities or blast induced cracks (m/s)
Rayleigh wave propagation velocity (m/s) c
S-wave – or transverse wave propagation velocity (m/s) c
sonic wave velocities (m/s)
subsonic speed (m/s) c
c t transient velocity (m/s)
D
* D drillhole-or borehole deviation (degree, % or m/m) D modulus of deformation (MPa) D
(degrees, mm/m or %) D
D c collaring deviation error in drilling (m or %)
D e equivalent support dimension (m)
D f fractal dimension (dimensionless)
D fs surface fractal dimension (dimensionless)
D i blast damage index (BDI) defined Yu and Vongpaisal, (dimensionless)
D ib blast damage index or damage index at blasting defined by
Paventi (dimensionless) D
setting-out deviation (error) in drilling (m) D
D T total borehole deviation or drilling accuracy (degrees, m or %)
< 1 (dimensionless) * d diameter (mm) d diameter of borehole or blasthole (mm or m) d
d c diameter of cartridge (mm or m)
critical diameter of cartridge (mm or m) d
external diameter (mm or m) d
diameter (mm) d
d o outside diameter or set outside diameter of a bit (mm)
optimal blasthole diameter (mm or m) d
diameter of plastic zone after crater blasting (m) d
diameter of rupture zone after crater blasting (m) d
d tc diameter of true crater after crater blasting (m)
E
E east (cardinal point) * E modulus of elasticity or Young’s modulus (MPa)
E d dynamic modulus of elasticity or dynamic Young’s modulus (MPa)
decrease Young’s modulus (MPa) E
eeffective Young’s modulus or effective modulus of elasticity (MPA) E
flexural modulus of elasticity for core specimen (MPa) E
quasi dynamic modulus of elasticity or quasi dynamic Young’s modulus (MPa) E
E t modulus of rupture in torsion (MPa)
e dilatation or volumetric strain (dimensionless) * e natural logarithm (dimensionless) * e void ratio (dimensionless) e
F
* F force, load or thrust (N or MN) F shape factor (dimensionless) F
F bi force on the drill bit or bit load (N)
F c crack extension force (N)
F f feed force on drill machine at drilling (N)
maximum force (N or MN) F
F t tangential force (N or MN)
* f confinement, degree of confinement, fixation factor (dimensionless) f factor or coefficient (dimensionless) * f frequency (Hz) f
b degree of confinement dependent on the bench slope in blasting (dimensionless)
f bi inclination factor for the blastholes (dimensionless)
boulder frequency (No./1000 t or No./1000 m3) f
f d frequency of discontinuities (No./m)
mean frequency of discontinuities (No./m) f
f i frequency of incoming blast wave (Hz)
frequency of joints (No./m) f
3-D volume density of joints (No./m3) f
joint plane spacing (dimensionless) f
RQD-value (Rock quality designation) (dimensionless) * f
(Hz or cycles/s)
natural frequency of a building (Hz) f
f o overbreak factor (%)
seismicity (No./year and 100 km2) f
stress reduction factor (dimensionless) f
f x ground vibration frequencies induced by a blast (Hz)
G
* G shear modulus of elasticity, modulus of elasticity in shear, rigidity modulus or modulus of rigidity (MPa)
G strain energy release rate (crack resistance, crack resistance energy, energy of rupture, fracture energy or fracture surface energy) (J/m2)
critical strain energy release rate (J/m2 orMJ/m2) G
strain energy release rate for a mode I loaded crack (J/m2 orMJ/m2) G
loaded crack, respectively (J/m2 orMJ/m2)
* g acceleration due to gravity (m/s2)
H
* H height (m) H height of specimen or beam (mm or m) H
height of abutment (m) H
H d height of tunnel, drive, crosscut, adit, incline or decline (m)
height of draw (m) H
height of lip of crater or crater lip height (m) H
h draw height (m) h
I
* I electrical current (A) * I impulse or momentum (Ns) * I movement of inertia of mass (kgm2) I sound pressure or acoustic intensity (W/cm2) I
block size index (m)
blasting index (dimensionless) I
coal dust index (%) I
I D density index (dimensionless)
joint intensity, number of joints per unit of area (No./m2) I
joint intensity, total joint trace length per unit of area (1/m) I
I L liquidity index (dimensionless)
maximum (recommended) firing current (A) I
I p drilling index
I P plasticity index (mass-%)
I rc rock quality index regarding drillability (kPa·min/m)
* I s point load strength or point load index (Pa or MPa)
I st stray current (A)
J
J a joint alternation number (dimensionless)
J d joint length density (1/m2)
J n joint set number (dimensionless)
J r joint roughness number (dimensionless)
J v number of joints per m3 orvolumetric joint count (No. of joints/m3)
J w joint water reduction factor (dimensionless)
K
* K bulk modulus or incompressibility (the inverse of compressibility) (Pa) K Fischer constant (dimensionless) K number of cycles at breakage of structure (No.) K
K c scaled strain intercept (dimensionless)
K d dynamic bulk modulus (MPa)
K o number of cycles when damage of a structure starts (No.)
K s shear stiffness (MPa)
K I , K
loaded cracks (MN/m3/2) * K
loaded crack (MN/m3/2) K coefficient of permeability or permeability coefficient (m/s).