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First, the amount of charge per hole of shallow hole blasting can be calculated according to the volume formula:
q=kW 3
Or q=kV-kɑHW
In the formula:
Q-load per hole, kg;
K-explosive unit consumption, kg/m 3 ;
V-single hole blasting rock volume.
The total amount of blasting is calculated as follows:
Q=Nq-kV total
In the formula:
Q- total amount of blasting explosives; kg;
N-the total number of blasting holes;
V total - the total amount of blasting of one blasthole; m 3 .
Second, deep hole blasting charge calculation:
(1) Calculation of the cost of a single deep hole blasting fashion:
Under normal circumstances:
Q=qɑHW d
When ɑ≥W d , replace the hole pitch with the chassis resistance line;
Q=qHW d 2
When the step slope angle is less than 55°, the chassis resistance line should be replaced with the minimum resistance line:
Q=qɑHW,
When W d is very different from the segment height H,
Q=qɑW d H 1
In the formula:
H 1 - conversion elevation, m.
H 1 = W d / ( 0.7 ~ 0.8)
When calculating the charge per hole by the above formula, it is also necessary to check with the maximum possible charge G of each hole.
G=g(L-Lr)
In the formula:
G-gun hole may be the maximum charge, kg;
G-the possible charge per metre of the blasthole, kg/m;
L-gun hole length;
Lr-filler length.
Should be satisfied: G ≥ Q is:
G(L-Lr)≥qW d ɑH
(2) Calculation of the volume of multi-row hole blasting fashion:
When multi-row hole blasting, the charge of the first row of holes is calculated as above, and the amount of charge should be increased from the second row.
Q 1 =kqɑbH
In the formula:
Q 1 - the amount of charge per hole in each row after the second row, kg;
K-rock resistance clamping coefficient, when using millisecond blasting, take k=1.0~1.2. When using blasting, take k=1.2~1.5, the second row of holes take the lower limit, and the last row of holes take the upper limit.
(3) Calculation of deep hole charge amount of inclined step
Q'=qWÉ‘L
In the formula:
Q'-the amount of charge per hole of the inclined hole;
Q-explosive unit consumption;
L-oblique hole (excluding ultra deep) length, m.
Tilting deep holes, the ultra-deep part of the dose should be calculated separately:
Q c =ph
In the formula:
Q c - ultra-deep part of the blasthole charge, kg;
P-charge per metre of blasthole, kg / m;
H-super deep.
(4) Subsection charge:
The charge of each segment of the segmented charge is calculated separately:
Q 1 =q 1 É‘W 1 2
Q 2 =q 2 É‘W 2 2
Q 3 =q 3 É‘W 3 2
...
In the formula:
W 1 , W 2 , W 3 - the minimum resistance line of each segment, m.
January 17, 2024