I. General regulations
When various blasting, blasting equipment destruction and blasting equipment warehouse accidental explosion, the safety distance between the explosion source and personnel and other protection objects shall be respectively determined and taken according to various blasting effects (earthquake, shock wave, individual scattered objects, etc.). value.
Second, the blasting earthquake safety distance
(1) The blasting seismic safety of general buildings and structures should meet the requirements of safe vibration speed. The safety vibration speed of the main types of building (structure) ground mass points is as follows:
1. Earthen cave, adobe house, and Maoshi house 1.0 cm/s
2, general brick house, non-earthquake large block building 2 ~ 3 cm / s;
3. Reinforced concrete frame house 5 cm/s;
4. The hydraulic tunnel is 10 cm/s;
5. The traffic tunnel is 15 cm/s;
6. Mine roadway:
The surrounding rock is unstable and has good support of 10 cm/s;
The surrounding rock is moderately stable with good support of 20 cm/s;
Surrounding rock stability without support 30 cm / s;
(2) The blasting seismic safety distance can be calculated according to formula (1)
Where: R—burst safety distance, m;
Q—explosive quantity, kg; the total amount of explosives is taken by blasting; the maximum amount of blasting is obtained by millisecond blasting or second blasting;
V-seismic safety speed, cm/s;
M—drug index, take 1/3;
K, α—the coefficient and attenuation index related to the topography and geology of the blasting point can be selected according to Table 1. Or determined by experiment.
Table 1 K and α values ​​of different lithologies in the explosion zone
(3) When blasting is carried out near a special building (structure) or in a complex blasting area, necessary monitoring or special tests of blasting seismic effects must be carried out to determine the safety of the protected object.
Third, the blasting shock wave safety distance
(1) When exposed to open blasting, the explosive quantity of one blasting shall not exceed 20kg, and the safety distance of the air shock wave to the occupant in the shelter shall be determined according to formula (2).
Where: R k — the minimum safe distance of the air shock wave to the person in the shelter, m;
Q—Explosive quantity of one blasting, kg; Q is calculated according to the maximum dose in each extension period when blasting is delayed; Q is calculated according to the total explosive quantity of one blasting when blasting in milliseconds.
(2) The blasting operation of the blasting operation index n<, for the protection of people and other protected objects, the safety distance of individual scattered objects and earthquakes should be first verified. When it is necessary to consider the protection against air shock waves, the safety distance is determined by the design.
(3) When underground blasting, the safety distance of air shock waves to personnel and other protected objects is determined by design. The safety distance of the air shock wave of underground large blasting shall be invited to be determined by experts and approved by the chief engineer of the unit.
(4) Underwater blasting When the thickness of the covered water is less than 3 times the radius of the package, the calculation principle of the safety distance of the air shock wave to the person above the water surface or other protection objects is the same as that during the ground blasting.
(5) Under the underwater blasting in waters with a water depth of not more than 30 m, the minimum safe distance of shock waves in water shall comply with the following provisions:
1. Determine the personnel according to Table 2;
Table 2 Safety distance of shock wave in water for personnel
2. For the ship:
Non-construction ship: 1000m upstream of the blasting point, 1500m downstream of the blasting point or in the still water area;
Construction vessel: Determined according to Table 3.
Table 3 Safety distance of shock wave in water for construction vessels
The amount of blasting explosives is more than 1000kg. The safety distance of shock waves in water for personnel and construction vessels can be calculated according to formula (3).
Where: R - the minimum safe distance of the shock wave in the water, m;
Q—the amount of explosive that is detonated once, kg;
K 0 — coefficient, selected according to Table 4.
Table 4 K 0 value
(6) Perform underwater blasting in waters with a water depth greater than 30 m, and the safety distance of the shock wave in the water shall be determined by actual measurement and experimental research.
(7) Underwater blasting in the vicinity of important waterworks, port facilities or other complex environments, testing and inviting experts to determine the safety distance should be conducted.
Fourth, the safety distance of individual scattered objects
When blasting (except for throwing blasting), the safety distance of individual scattered objects to personnel shall not be less than that specified in Table 5;
The safe distance to equipment or buildings should be determined by design.
When throwing blasting, the safety distance of individual scattered objects to personnel, equipment and buildings shall be determined by design and reported to the chief engineer of the unit for approval.
V. External safety distance in the reservoir area and safe distance between the reservoirs
(1) When setting up blasting equipment warehouse or blasting equipment in the open air, the distance between the warehouse or the pile to the external protected objects shall be determined according to the following conditions:
1. The starting point of the external distance is the outer wall wall of the warehouse, the edge of the medicine pile, and the mouth of the tunnel type storage;
2. When determining the external distance, the nature of the explosive may not be considered;
3. When there is more than one warehouse or drug heap in the storage area of ​​the blasting equipment, the external distance shall be verified according to each warehouse or drug pile;
4. Determine the distance between the warehouse or the drug pile to the residential area of ​​the enterprise or the edge of the village. The ground warehouse or medicine pile is not less than the provisions of Table 6: the tunnel type warehouse is not less than the provisions of Table 7.
Table 5 Safety distances of individual scattered objects to personnel when blasting (except for blasting)
Note: 1 When blasting along a hillside, the safe distance of the flying rock in the downhill direction should be increased by 50%.
2 The amount of bare blasting charge (including the amount of detonating charge used at the same time) for simultaneous detonation or millisecond delay. Should not exceed 20kg.
3 To prevent ships and rafts from entering dangerous areas. Lines and signals should be blocked with peripherals at minimum safe distances upstream and downstream.
4 When the blaster is placed deeper than 50m in the well, the minimum safe distance can be reduced to 20m.
Table 6 Minimum external distance from the ground blasting equipment library or stack to the edge of a residential area or village
Note: The distance in the table is suitable for flat terrain. When the following specific terrains are encountered, the values ​​can be increased or decreased as appropriate;
1 When the dangerous building is placed close to the foot of the mountain 20 to 30 m high. When the slope of the mountain is 10 to 25 degrees, the distance between the dangerous building and the building behind the mountain can be appropriately reduced by 10% to 30% compared with the flat terrain;
2 When the dangerous building is placed at the foot of the mountain 30 to 80 m high and the slope of the mountain is 25 to 35 degrees, the distance between the dangerous building and the building behind the mountain can be reduced by 30% compared with the flat terrain. ~ 50%;
3 In a ravine, the height of one side of the mountain is 30 to 60 m, the slope is 10 to 25 degrees, the height of the other side is 30 to 80 m, the slope is 25 to 30 degrees, the width of the ditch is about 10 m, and the two buildings placed at the foot of the two slopes in the ditch are The distance between the two should be increased by 10% to 50% compared with the flat terrain;
4 In a ravine, the height of one side is 30 to 60 m, the slope is 10 to 25 degrees, the height of the other side is 30 to 80 m, the slope is 25 to 35 degrees, the width of the ditch is 40 to 100 m, and the longitudinal slope of the ditch is 4 to 10%. The distance between the depth of the ditch and the direction of the exit of the ditch should be increased by 10% to 40% compared with the flat terrain.
Table 7 Minimum external distance from tunnel diversion to residential or village edge
When determining the distance according to Table 7, the data should be based on the data in the table (Figure 1), and the protected residential area or village should be located outside the envelope of the diagram (dashed line in Figure 1).
Figure 1 is a diagram to determine the distance between the library and the residential area or village.
In the figure, point O is the center of charge, which is the center of the map from 90° to 180°; point O' is the center of the mouth, which is the center of the map from 0° to 90°.
5. For the distance from the warehouse or the drug pile to other protected objects, the protection level coefficient of each protection object shall be determined according to Table 8, and the distance specified in Table 6 and Table 7 shall be multiplied by the specified coefficient to determine.
Table 8 Degree of protection of various protected objects
NOTE: Cave axis within ± 90 ° ~ ± 180 ° range, if high-rise building (structure), when the iron tower transmission line, should by seismic safety evaluation, special protection level determining factor.
(2) To determine the safe distance between warehouses, the following provisions shall be observed:
1. The distance between the A 1 warehouse or the drug stack is not less than the provisions of Table 9;
Table 9 Minimum distance between A Class 1 warehouses
Note: This form is applicable to black gold , ammonium ladder black explosives, black ladder medicine injections and gelled explosives.
2. The distance between the A 2 warehouses or the drug piles is not less than the provisions of Table 10;
Table 10 Minimum distance between A Class 2 warehouses
Note: This table is applicable to TNT, detonator and detonating cord. The detonator and detonating cord are calculated according to their charge.
3. The distance between the A 3 warehouses or the drug piles is not less than the provisions of Table 11;
Table 11 Minimum distance between A Class 3 warehouses
Note: This watch is applicable to ammonium nitrate explosives and black powder.
4. In the range of 75° around the axis of the tunnel of the tunnel type warehouse, it is not advisable to set up other blasting equipment warehouses or medicine piles.
Xinxiang SKF Machinery Providing the highest precision solutions for all materials and industries. And specialzied in the design, research, manufacture and sales of high precision double side surface grinding mahcine.
Xinxiang SKF Machinery Co., Ltd Double Side Surface Grinding Machine are suited for unlimited applications, from automotive, aerospace, semiconductor, ceramics, plastics, powder metallurgy, carbide tools, etc.
Max size of parts: 330mm
Flatness: 0.002mm
Parallelism: 0.002mm
Surface roughness: Ra 0.1um
Double Side Surface Grinding Machine
Double Side Surface Grinding Machine,Surface Grinding Machine,Double Surface Grinding Machine,Double Disc Surface Grinding Machine
Xinxiang SKF machinery Co., Ltd. , https://www.facegrindingmachine.com