DRILLING ÄND BLASTING OF ROCKS CARLOS LOPEZ JIMENO Project Director for EPM, SA EMLIO LOPEZ JIMENO FRANCISCO JAVIER. Submitted By. drilling blasting rocks filetype pdf free Engineer requires continuous use of drilling and blasting or special power. Facts About: Underwater Drilling. faced with a number of challenges in the area of drilling and blasting such as blasting cost, explosives consumption, airblast, blast induced ground vibration and flyrocks. Sorry, there is no online preview for this file type.
Geotechnical engineeng techniques und pracdces. The quantity of ore extracted can be as large four meters vertically, because the total height of the excavation would be excessive and the blastholq are placed with a 50 to 65′ inclination. When using air with top hammers, it is not filetpe to have a high pressure compressor for flushing alone.
The important historical events which have marked an era were the invention of dynamite by Alfred Nobel inthe use of ANFO starting in blastinng, the development of slumes from the late fifties on and, lastly, the preparation of blasting agents such as emulsions, heavy ANFO, etc.
Meanwhile, the cylinder front end 5 is at atmospheric pressure since the exhaust port 6 is Open. Charging and Dewatering Equipment. In relation with the height of the chambers, these are classified as follows: This is often done by connecting these labors with the previous drifts.
The height of the colurnn charge is calculated by the difference between the length of the blasthole and the sum of the stemrning length and that of the bottom charge. E Seccionado de Cargas: Demolition filletype the shucture of a concrete building. Spherical charges development vertical crater retreat method in stope und pillar driling. The loading flow of these tmcks varies between and kglmin. Deposits on a rnix-load tmck. The working pressures go from 0.
Drilling and Blasting of Rocks – CRC Press Book
Fiushing with air is used in surface operations, where the dust produced can be eliminated by means of dust collectors. From this it can be Seen that the drilling diameter that gives minimum costs of fragmentation with explosives is not always the Same,’ Fig. Owing to the inconveniences that the angulation of the mast presents in this type of drills, especially in hard rock, vertical drilling is systematically used. Structure and Building Demolition The number and length of the opened and developed cracks strongly depend upon the pressure of the gases, and a premature escape of these due to insufficient stemming or by the presence of a plane of weakness in the free face could lead to a lower performance of the explosive energy.
The backedge of the piston flange uncovers the exhaust port. On the other hand, depending upon the type of mining or civil engineenng surface project, the most comrnon equipment and diameters for bench blastings are indicated in Fig.
It is used in surface projects as well as in underground operations, usually with vertical blastholes, although horizontal holes can be drilled on occasion.
The purpose of this Handbook is to give basic knowledge of the drilling systems, the types of available explosives and the accessories and the parameters that intervene in blast designing, whether controllable or not; at the same time the objectives and contents contribute to improved safety in mining.
Recent und future development in surface coal mining. On the other hand, quality control is more difficult than with pump trucks. Masonry bridges This is the oldest type of construction and it usually has, pillars, abutments and arches of masonry of quite large size, along with materials like mass concrete injected rockw gravel, Fig.
Even though this practice gives quite good fkletype, there are filettype in which the changing conditions of the rock masses make the cutting of the rocks in the lower part of the benches more difficult.
Drilling and Blasting of Rocks – [PDF Document]
The decrease in dynamic tensile strength of the rock and the attenuation of the Strain Energy. Specific drilling of four types of rock in 12 m high benches. Typically a rock support system would include a number of these support methods, each intended to undertake a specific role in the rock support such as the combination of rock bolting and shotcrete.
In view of these advantages and characteristics, the type of operations where it is used are: Steels nch in carbon, chains, cables, reinforcing bars, high resistance elements, etc. It is quick and efficient, having been successfully tned in blastholes of up to mm in diameter. Real rocks are deformed and consolidated at the Same time: All instructor resources are now available on our Instructor Hub. The loading costs are calculated with a rate equation: For button bits from 51 to 89 mm, the speeds should be lower, between 40 and 60 r.
The initiation should be carried out with rnillisecond delay detonators and the surfaces that are to be blasted should be carefully covered. A variation of the room and pillar method in inclined orebeds is composed of sloping drifts which serve as access to the operation zones and can be climbed by the jumbos. The optimum displacement results are obtained with reduced burdens between filetyep.
Not so easy to blast. Note than the front edge of the control head 7 is just about to Open the back supply port.
Drilling and Blasting of Rocks
Piston at the end of its return stroke. The texture of the rock also has influence blastig this Parameter, as the elasticity module in the direction of the bedding or schistosity is usually larger than when perpendicular. Apart from this, an additional cost must be taken into consideration due to secondary fragmentation of boulders or blocks of rock that cannot be handled by the loading, haulage and crushing equipment.
Tunnel construction Mining Explosives Civil engineering. It is the equivalent of the powder factor of gellatin dynarnite necessary to fragment the rock, normally between 0. Since the fifties, many formulas and methods to deter In other projects Wikimedia Commons. The total energy consumed by the equipment is 2xNrTr? Drioling wire laid in the hole during this process was then removed dgilling replaced with a train of gunpowder.
Drilling and blasting
Home Documents Drilling and Blasting of Rocks. Design and Performance of Underground Excavations. I1 Curso sobre Control sion energy infans und rings of blasrholes. This sequence repeats itself with the Same impact rhythrn of the piston upon the system of energy transmission to the bit.