What is blast air decking?
The use of air space or a void within a blast hole between an explosive charge and inert stemming to enhance the shock wave detonation force.
What is burden and spacing in blasting?
The term SPACING denotes the lateral distance on centers between holes in a row. The BURDEN is the distance from a single row to the face of the excavation, or between rows in the usual case where rows are fired in sequence. Chapter 8. BLAST DESIGN.
What is Post splitting in blasting?
Post-split blasting consists of drilling a row of closely spaced blastholes with a spacing to burden ratio greater than 1.0 along the final limit (Figure 5.). To avoid loss of blastholes through caving, post-splitting blastholes should be drilled after firing the adjacent production shot.
What is buffer holes in blasting?
Cushion blasting, another type of controlled blasting that’s typically done after production blasting, uses a row of lightly loaded “buffer” holes filled with crushed stone (stemming), which reduces the impact on the surrounding rock as well as the finished slope face.
What is Deck charging?
Deck charge is divided into multiple sections of the column charge, by air, water, rock slag and other separation. According to the principle of resonance detonation of detonation energy, it is a method of rational allocation of energy.
What is the K factor in blasting?
K-factor – A scaling factor correlating the distance (D) and Net Explosive Weight (W) with a particular peak incident overpressure based on the Kingery-Bulmash relationship, as shown in Figure 1.
What is deck charge?
[′dek ‚chärj] (mining engineering) A charge that is separated into several smaller components and placed along a quarry borehole.
What is Deck charging in mining?
i. A charge that is divided into several separate components along a quarry borehole. Compare with: columnar charge. ii. A charge separated by stemming.
How do you calculate live load on a deck?
Therefore, a deck of 120 square feet multiplied by 50 shows that your deck can hold 6000 pounds, including the structure. Dividing by 5 will allow you to determine that 4500 lbs is the max live load your deck can hold.
What is decking a load?
The load that is placed on your deck is expressed in pounds per square foot (psf) and the total load or more appropriately, the design load, is comprised of the dead load and the live load. Dead load is basically the load created by the weight of the deck itself. This is usually about 10 psf.
What is deck mining?
A method of loading blast holes in which the explosive charges, called decks or deck charges, in the same hole are separated by stemming, air cushion, or a plug.
What is deck loading?
How is air decking used in underground blasting?
Better Air Decking using the Saver Plug, offers a reduction in fly rock, vibration, drilling costs, and the volume of explosives used in blasting. It is used across all sectors of the mining industry, including underground horizontal hole blasting. Increased fragmentation and cast percentage is achieved with the same or reduced Powder factor.
How is air deck blasting used in imp rovemen?
Air deck blasting is one of most com monly used for imp rovemen t o f b lasting eff iciency. It is comple tel y cha n ges the blas tin g m e c h anism p hen om ena fo r trans f er of bla sting mechan i s m to under stand the phenom en a of rock breakage under air space.
What happens when an Explosive Hits the air deck?
The path of least resistance is always taken by the shock waves when an explosive detonates in a borehole. The bottom portion of the hole in the air deck will first be subjected to a high intensity shock wave. After the initial shock wave front hits the bottom of the hole it creates a reflection and increases the pressure at that point.