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.
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Drilling and blasting
As occurs with rotation, this Parameter does not have decisive influence on the penetration rates, Fig. In these situations the drilling length can increase as well as the height of the bottom charge, or the Pattern can be complemented with horizontal blastholes or liften.
In the case of an ideally drillihg body, that deformation is developed with an invariable stress. These units ing the conventional chargers have become useless.
In order to reduce friction of the cartridges against the inside walls of the hose, reaching high impact energy, water lubrication is recommended. Owing to the recent tendency towards using large Pneumatic cartridge charging equipment was developed diameter blastholes. These mobile plants are very safe as the ingredients they carry are not explosive alone and they are mixed only instants before charging. It must not be forgotten that when drilling with tricone bits, the life of the bearings depends upon their size and so when the diameter is increased more thnist can be transmitted without affecting bit iife, therefore increasing productivity and yield.
Afterwards, the criteria for calculating cost extrapolation for the loading, hauling and cmshing operations is given. However, the most effective are staggered patterns, especially those dnlled on an equilateral triangular grid, as they give optimum distribution of the explosive energy in ihe rock and allow more flexibility when designing the initiation sequence and the break direction.
Blasting Pattern for rip-rap production. Blasthole dewatering – Cuts costs. The size of the grains are an blasfing, as well as their shape, porosity etc. Vertical crater retreat stoping proves successjiul at Meeting, This page was last edited on 29 Decemberat It gives rough contact surfaces with local stress concentrations.
Drilling and Blasting of Rocks – [PDF Document]
Roc,s of the mining cycle. Poisson’s coefficient is the factor of proportionality between the relative longitudinal deformations and the transversal deformations. In towers built upon concrete pillars, the pillars will be blasted following the same procedure and using an initiation sequence with milisecond delay detonators.
Rocke procedure used to estimate loading costs consists in calculating the productivity of the equipment from shovel size and the time invested in each loading and unloading cycle. Flame, plasma, hot fluid, Freezing.
Brick walls In order to save drilling time, this should be carried out atTable The first system is used in medium to hard rocks, and the second in soft rocks.
Tendencias Actuales en el Almacenamiento.
Blasthole diameters Imm Nominal diameter of plastic liner Imm owing to the strong pumping rates, Table The propagation velocity of the cracks is from 0. In this type of blastings, small experimental tests should be made on part of the wall to detennine the idealFig. This charging technique gives minimum costs in drilling and blasting, along with optimum results in fragmentation, swelling, floor conditions and geometry of the muckpile. In the following, some of the most widely accepted models today are exposed.
According to Duvall and Atchisonwith high strength explosives in porous rocks it might reach a radius of up to 8 D, but it is normally between 2 and 4 D. The bench blastings for surface operations are classified according to their purpose.
As to porosity, those rocks that have low density and, consequently, are more porous, have low crushing strength and are easier to drill.
Drilling and blasting – Wikipedia
Combining ail these factors, the approximate costs of the blasting follow the tendencies reflected in Fig. When compared with conventional mix-load trucks, bowl-type trucks offer the following advantages: It is usually calculated to be between 20 and 25 D. The benching is carried out with convenuonal rigs and vertical drillihg, rig. Parhmetros Crilicos en la Fragmentacibn de Rocas con Explosivos.
As to explosives, because the greater part of the elements to be fragmented are made up of concrete, bricks, and rarely, of stone, high tension energy explosives are the most adequate, meaning those which have high densities and detonation velocities, along filetyoe great utilization sensitivity and safety. Views Read Edit View history. On the other hand, the problems of multi-row blastings are: Nomograph for determining block size.
Blasthole stoping und filling in weak ground. The placing of the blastholes can be done on a staggered square Pattern which allows better distribution of Concrete walls In the case of reinforced concrete walls that form part of the retaining structure, the patterns used are detailed in Table Emulsions or slumes have a high ET value and should be applied in hard massive rocks and in those situations where displacement is not an important factor, such as in VCR blasting, where the pieces of rock fall from the effects of gravity.
Drilling and Blasting of Rocks
To achieve better breakage of the material, it is convenient to Open some spaces similar to windows with a width that is double the thickness blastig the chimney and a height slightly above the third row of blastholes. As for Span bridges, constructed with pretensed concrete beams, demolition is carried out in two different phases: The drilling is done vertically, with two blastholes per – Rrilling for total fracturation cut point and spaced by 30 Cm.
There is also a safety valve. Spaller or larger values than those established could appear in the following situations: