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.
By taking into account the compressive strength of the rocks and the drilling diameter, the fields of application of the different methods can be defined as refiected in Fig. The fall of the chimney is eliminated by blasting part of the sustaining base in such a way that the vertical of the Center of gravity moves out of the remaining base, producing a lack of balance of the constmction and a turning of the same in a deterrnined direction, as happens during the felling of a tree, Fig.
Driilling injluence of controllable blast parmeters on fragmentation and mining costs. If the explosive columns are intersected lengthwise by a pre-existing crack, these will Open with the effect of the strain wave and the development of radial cracks in other directions will be limited.
These have a hopper of ammonium nitrate and a tank of fuel oil. AcknowledgementsThe authors wish to express their most sincere gratitude to the following experts, companies and official organisms for their collaboration and release of technical material as well as permission to reproduce certain data and figures.
All these aspects have significative influence on drilling performance. Recycling of Demolished Concrete and Masonry Illustrated ed. Deposits on a rnix-load tmck. Please accept our apologies for any inconvenience this may cause.
The fill factors that correspond with roks relative size are indicated in Table Experimentally, this velocity has been calculated using the following equation: Sometimes values of 2 or more are used. Blating, the mining is divided into phases which begin in the top part with a pilot drift 1 and lateral stope holes 2to follow by benching in the lower part with horizontal or vertical blastholes 3Fig. This article incorporates text from this source, which is in the public domain.
While drilling and blasting saw limited use in pre-industrial times using gunpowder such as with the Blue Ridge Tunnel in the United States, built in the sit was not until more powerful and safer explosivessuch as dynamite patentedas well as powered drills were developed, that its potential was drillign realised.
Drilling and blasting
The influence of these fissured beds of the rock can be evaluated by considering the different types of fillings of the joints and consequently the different coefficients of absorption of the strain waves when they Cross these planes. From these access drifts, other horizontal dnfts are excavated at intervals, following the ore boundary as closely ciletype possible.
Swedish Mining Research Foundation, The explosive is important not only for the energy it develops but for its actual yield. During this Stage there is filetyppe compressed ar pushing against the piston from the front end 5 and also pushing against the back end Blast design considerationsfor underground mining and construction operations.
The fiiletype of C, and C2 are calculated considering that K, and K2 are equal to 1, which implies that, for the moment, the burden and spacing are equal: It is of vital importance in this System to have a correct design of the centralizer in the charging tube. Sideling Hill road cut formed by rock blasting.
Bench blasting is the easiest and therefore should be used as rockss as possible. Parhmetros Crilicos en la Fragmentacibn de Rocas con Explosivos. Electric arc, magnetic induction.
Underground Mining Methods Handbook. However, those parameters are usually subject to some on the indicated calculations and estimations.
Concrete walls Cast into the ground In these instances, where the walls are usually high, narrow and cast into the ground, the blastholes are drilled vertically to achieve fragrnentation of the concrete and3 14Drilling und blasting of rocks facilitate its digging and haulage, Fig. The rocks that contain quartz grains are highly abrasive.
Other criteria to be accounted for in the selection of drilling equipment are: When analyzing the actual blast criteria, the most important are: Cornpany Estudios y Proyectos Mineros, S. Loading blast holes with ANFO. A number of controlable Parameters influence fragmentation, as well as the rock properties themselves.
Comparison between a square pattem a versus a staggerd pattem with equilateral triangles b 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.
Partial demolition of a breakwater wall. If the ground is good, a systematic bolting of the surface with gunite reinforcement steel ribs is usually performed and, if the rock is poor, the excavation is carried out in transversal sections, leaving between them others that are not excavated until the arches aiready opened have been concreted.
Estimated drilling und blasting cost – An analysis und prediction model. Fundaci6n G6mez Pardo, Rock type Specific gravity m3 2. Volume of a high and narrow wall. In blastings where large blocks result from stemming, short pocket charges should be used, Fig. If there is water present in the blastholes, the loading can be done after placing a plastic liner. As to porosity, those rocks that have low density and, consequently, are more porous, have low crushing strength and are easier to drill.
The efficiency of this transmission is difficult toRotary percussive drillingTahle 2. The guidelines to follow for the design of rip-rap blastings are: Concrete bridges Within this group, which is the most recently constructed,Fig. Cobeiia Precision Blasting Services: It must be taken into account that drilling costs usually This chapter will study the first three types of blastdescend as the diameter increases. The yield of the chargers depends upon the interior diameters of the hoses and their length, which should never be over 50 m, and the inclination of the boreholes.
The first are applied to small and medium diameter 63 to rnm blastholes with a maximum bench height of about 15 meters.