Numerical and experimental investigation of blasting ...

Apr 10, 2018· The presplit-smooth blasting approach inherits the advantages of both presplit and smooth blasting and improved the blasting damage control effect significantly. The emphasis of this study is to evaluate the differences in the damage processes of the smooth and presplit blasting …

Aesthetic Blasting - Page 6 of 7 - GeoPrac.net

Smooth Blasting. In presplit blasting, the slope is defined by carefully aligned blast holes, containing light charges, which are fired prior to the detonation of production blast holes, either separately or within the same blast on an early delay. Either way, at the time the presplit blast holes detonate, their burden is mechanically infinite ...

1. Controlled Blasting Techniques-2011 | Drilling (111 views)

1. Controlled Blasting Techniques-2011 - Download as Powerpoint Presentation (.ppt), PDF File (.pdf), Text File (.txt) or view presentation slides online. control blasting techniques ... PRESPLIT BLASTING. CMRI Principle of Pre-split blasting: ... More drilling than in smooth blasting Ground vibration and air overpressure problems Practice ...

smooth blasting presplit - bondhumahal.in

smooth blasting presplit . Precision Presplitting: The Basics - Rock Products. Precision Presplitting: The Basics to presplit the weak or heavily jointed with typical presplit blasting, siltstones can be presplit to form smooth, Contact Supplier Technical Blasting - National Quarry Services, Inc.

PRESPLITTING ROCK IN THE PRESENCE OF A STATIC …

Preliminary tests on presplitting rock in the presence of an in situ static stress field were undertaken to study the influence of a horizontal static stress field on the creation of a vertical presplit fracture plane. These tests indicated that it is easier to fracture the rock parallel to the

Explosives Engineers' Guide - Dyno Nobel

Presplit blasting Spacing = Hole diameter x 12 Burden = 0.5 x production blast burden (B) Uncharged length at top = 10 x D Powder factor = 0.5kg per square metre of face Do not stem holes. Fire all holes on the same delay, or in groups of ≥ 5 holes Smooth Blasting Spacing = 15 x Hole diameter (hard rock) 20 x Hole diameter (soft rock)

Techniques of Controlled Blasting - SlideShare

Dec 17, 2009· Following are the techniques of controlled blasting: Line drilling, Trim (Cushion) blasting, Smooth (contour or perimeter) blasting, Pre-splitting, Selecting and employing various parameters of blast design, using modern technology, Precise and accurate timing delays, Muffle blasting at critical and congested areas. 4 5.

Resolution of Some Common Problems Highway Blasting

Resolution of Some Common Problems Highway Blasting In • ... The first presplit blast caused the entire ... Smooth blasting minimizes the danger of displacing the rock mass until each successive portion has been fragmented during the planned blasting sequence.

FHWA State Geotechnical Workshops - GeoPrac.net

Smooth Blasting. In presplit blasting, the slope is defined by carefully aligned blast holes, containing light charges, which are fired prior to the detonation of production blast holes, either separately or within the same blast on an early delay.

WALL CONTROL BLASTING TECHNIQUES - .com

Feb 25, 2011· Wall failures are costly and often life threatening. The goal of efficient wall control blasting is to make transition from a well fragmented rock …

Comparison of Presplit and Smooth Blasting Methods for ...

To understand differences of smooth and presplit blasting for the excavation of rock wells, two field experiments using these two techniques are implemented at the same test site, respectively. The ground vibrations induced by them have been monitored with the …

FINAL WALL STABILITY IN METAL OPEN PIT MINES USING ...

PRESPLIT BLASTING Presplit blasting is an effective technique for stabilizing the final wall in open pit metal mines. This technique is based on the phenomenon that the detonation shock wave is stopped and reflected at any free face. In presplit blasting, an intentional fracture is created at the excavation line prior to the detonation

Case Study Controlled Vibration Blasting

a presplit line was run along the back of the blast on the side closest to the structure. This served two purposes; since it was a final wall blast it helped to create a smooth wall, and the crack produced from barrier against transmitting blast vibration towards the structures. Where R = dist. (m) Q = mass

Theoretical Concept to Understand Plan and Design Smooth ...

Apr 15, 2008· The model firstly illustrates that rock burden for each hole should be sub-divided into thin micro strips/slabs to understand the characteristics of wave transmission through the medium and lastly with the help of beam theory of structural dynamics have put forward a mathematical model to analyze and design an effective smooth blasting pattern ...

FHWA - Center for Local Aid Support - Publications

Each type of blasting-presplit, smooth, and cushion blasting-has its own formula. Presplit Blasting. As discussed above, presplit blasting (or presplitting) is most often done before production blasting to create a secondary fracture plane that will protect the final slope face from damage in the main production blast.

Comparison of Blast-Induced Damage Between Presplit and ...

PDF | This paper focuses on the comparison of damage induced by smooth blasting and presplit blasting based on the excavation of high rock slope. The whole damage process of the smooth blasting ...

A REVIEW OF THE DESIGN CRITERIA AND PRACTICAL …

A REVIEW OF THE DESIGN CRITERIA AND PRACTICAL ASPECTS OF DEVELOPING A SUCCESSFUL PRE-SPLIT. Simon St J Tose ... unconsolidated, weathered or highly fissured rocks, problems in obtaining a consistently smooth wall are usually encountered, but the overall result is always much better than the result from production ... As with Smooth Blasting ...

FHWA - Center for Local Aid Support - Publications

These techniques are presplit blasting, smooth blasting, and cushion blasting. Presplit Blasting: Presplit blasting, or presplitting, is used before production blasting to protect the final rock face from damage caused by the production blasting. Presplitting creates a fracture plane along the final slope face, which prevents the radial cracks ...

Summary of Surface Blasting and Damages with Analysis of ...

Comparison of Blast-Induced Damage between Presplit and Smooth Blasting of High Rock Slope by Hu et al. (2013) Advance of computers has allowed for more modeling techniques over the last decade. This is noted by the use of numerical modeling comparing the damages of presplit and smooth blasting for the study done by Hu et al.

Comparison of Presplit and Smooth Blasting Methods for ...

To understand differences of smooth and presplit blasting for the excavation of rock wells, two field experiments using these two techniques are implemented at the same test site, respectively. The ground vibrations induced by them have been monitored with the different distances through the corresponding devices. The vibration results illustrate that at the same monitoring distance and ...

pre-splitting | Encyclopedia.com

pre-splitting A method of blasting in which a planar crack is propagated by blasting to determine the final shape of a rock face before holes are drilled for the final blast pattern; firing with a minimum time scatter can then be used. The crack helps to screen the surroundings from ground vibrations during the firing of the main round. Source for information on pre-splitting: A Dictionary of ...

Comparison of Blast-Induced Damage Between Presplit and ...

ORIGINAL PAPER Comparison of Blast-Induced Damage Between Presplit and Smooth Blasting of High Rock Slope Yingguo Hu • Wenbo Lu • Ming Chen • Peng Yan • …

Controlled blasting for enhanced safety J in the ...

Blasting is a daily practice on the mines and ... presplit is performed with decoupled charges, such as the ... In smooth wall blasting, the final row of holes contains a lighter than normal charge, possibly a smaller burden and is ignited after the main charge is completed in order to limit the

Back to Basics - iseegoldenwest.org

Smooth-blasting – A cautious blasting technique similar to pre-splitting, except that the holes are detonated after the production holes in the main blast. The intent is not to form a crack, however, but to blast loose the remaining burden with the lighter charges without causing ... Back to Basics

Improved Blasting and Bench Slope Design at the Aitik Mine

effects of small-scale structures could be controlled through lighter smooth blasting, whereas the impact of larger, more dominant, structures, prevailed even for very light smooth (for open pit operations) blasting. For the footwall, presplit blasting in inclined (70°) …

Precision Presplitting: The Basics - Rock Products

May 26, 2016· Another feature of a precision presplit is that it's bottom-primed with either a cast booster or a cap-sensitive chub of emulsion or dynamite. While this does add a little extra power to the bottom of the blast, the main benefit is the extra weight it gives on the detonating cord. This makes the blast much easier and quicker to load.

"WALL CONTROL BLASTING AT THE ORPHAN BOY MINE – BUTTE ...

To explore the applicability of control blasting in underground mining operations, protect the safety of students, faculty, and staff, prevent overbreak, and to ensure the stability of openings and workings, four experimental control blasts, comprising of three smooth blasts and one presplit blast were conducted at the Orphan Boy Mine (an ...

Rock Blasting and Associated Damages | Geoengineer.org

6.2. Comparison of Blast-Induced Damage between Presplit and Smooth Blasting of High Rock Slope by Hu et al. (2013) Advance of computers has allowed for more modeling techniques over the last decade. This is noted by the use of numerical modeling comparing the damages of presplit and smooth blasting for the study done by Hu et al.

Blasting damage in rock - rocscience.com

correctly designed and executed, smooth blasting can be very beneficial in trimming the final excavation face. Figure 1 illustrates a comparison between the results achieved by a normal blast and a face created by presplit blasting in jointed gneiss. It is evident that, in spite of the fairly

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