• Comparison of Blast-Induced Damage Between Presplit and

    Abstract 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 and presplit blasting excavation method is studied by using a cumulative blasting damage numerical simulation technology based on the secondary development of the dynamic finite element code LS

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  • 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

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  • A better way to presplitMining Construction online

    2011-8-3 · With ROC rigs presplit holes can always be drilled as planned. Furthermore ROC rigs are not just better at presplit drilling they can also be used for a variety of other tasks such as leveling benches for the large rigs complementary drilling of buffer holes up to 203 mm drilling long horizontal dewatering holes or using the Reverse

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  • Comparison of Blast-Induced Damage Between Presplit and

    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 and presplit blasting excavation method is studied by using a cumulative blasting damage numerical simulation technology based on the secondary development of the dynamic finite element code LS-DYNA.

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  • Blasting damage in rockRocscience

    2018-9-21 · 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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  • FINAL WALL STABILITY IN METAL OPEN PIT MINES USING

    2016-9-19 · The common controlled blasting techniques are line smooth cushion and presplit blasting. The latter technique has become the most widely used in metal open pit mines due to good results and its operational nature in hard rock formation. PRESPLIT BLASTING Presplit blasting is an effective technique for stabilizing the final wall in open pit

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  • A REVIEW OF THE DESIGN CRITERIA AND PRACTICAL

    2006-3-22 · Smooth Blasting The back holes are fired last as usual relying on a reduced charge mass per hole for overbreak control. The South African Institute of Mining and Metallurgy International Symposium on Stability of Rock Slopes in Open Pit Mining and Civil Engineering

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  • Comparison of Blast-Induced Damage Between Presplit and

    Abstract 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 and presplit blasting excavation method is studied by using a cumulative blasting damage numerical simulation technology based on the secondary development of the dynamic finite element code LS

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  • FINAL WALL STABILITY IN METAL OPEN PIT MINES USING

    2016-9-19 · The common controlled blasting techniques are line smooth cushion and presplit blasting. The latter technique has become the most widely used in metal open pit mines due to good results and its operational nature in hard rock formation. PRESPLIT BLASTING Presplit blasting is an effective technique for stabilizing the final wall in open pit

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  • Paper Improved Blasting and Bench Slope Design at the

    The detrimental 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°) holes over the full double-bench height proved to be

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  • A better way to presplitMining Construction online

    2011-8-3 · With ROC rigs presplit holes can always be drilled as planned. Furthermore ROC rigs are not just better at presplit drilling they can also be used for a variety of other tasks such as leveling benches for the large rigs complementary drilling of buffer holes up to 203 mm drilling long horizontal dewatering holes or using the Reverse

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  • Comparison of Blast-Induced Damage Between Presplit and

    2013-9-14 · Comparing the presplit blasting and smooth blasting holes they have similar charge structures and blasting parameters so the peak value and rise time of the blasting load are almost the same. However the burden of presplit blasting is much greater than that of smooth blasting

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  • Numerical and experimental investigation of blasting

    2018-4-10 · 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 methods.

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  • Safety threshold of blasting vibration velocity in

    2020-6-19 · Blasting damage control is one of the main problems in the dam foundation excavation of Baihetan Hydropower Station and it is important to study the relationship between the blasting vibration and blasting damage. In this paper a horizontal presplit blasting experiment was carried out at the dam foundation. By combining vibration monitoring and sonic wave detection before and after blasting

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  • Pre-Split Blast Design For Open-Pit And Underground Mines

    PRE-SPLIT DESIGN THEORY Various theories have been put forward over the years regarding the mechanism by which a presplit mine is formed. Most of these theories involve the interaction of the ground vibrations resulting from the detonation of the explosives In the pre-split blast holes.

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  • Safety threshold of blasting vibration velocity in

    2020-6-19 · Blasting damage control is one of the main problems in the dam foundation excavation of Baihetan Hydropower Station and it is important to study the relationship between the blasting vibration and blasting damage. In this paper a horizontal presplit blasting experiment was carried out at the dam foundation. By combining vibration monitoring and sonic wave detection before and after blasting

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  • CHAPTER 3ROCK EXCAVATION METHODS Asad Aijaz

    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.

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  • Explosives Engineers Guide

    2020-4-22 · 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)

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  • Pre-Split Blast Design For Open-Pit And Underground Mines

    SYNOPSIS Perimeter blasting techniques limit damage to the final walls of excavations. This is accomplished by lowering the explosive energy concentration of the excavation boundary. The most common method is pre-splitting which involves the formation of a crack coincident with the excavation boundary prior to firing the main blast.

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  • controlled blasting.PDFWall Control(construction by

    EXPLOTECH Presplitting (Preshear Smooth Blastin A technique designed to provide the best possible p the final excavation wall Row of presplit holes are drilled at reduced spacing burden Presplit row may be fired days in advance of drillin blasting the production holes or at least 200 ms pri production holes in the same blast Holes are loaded with decoupled charges Presplit holes are detonated

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  • Explosives Engineers Guide

    2020-4-22 · 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)

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  • Resolution of Some Common Problems Highway Blasting

    Smooth blasting minimizes the danger of displacing the rock mass until each successive portion has been fragmented during the planned blasting sequence. It is possible also to lessen the tendency of presplitting to displace rock by introducing more delays into the blast. The­ oretical considerations suggest that it is necessary to detonate

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  • Final Wall Stability in Metal Open Pit Mines Using

    2016-9-19 · Importance of presplit drilling and blasting in open pit mines. slope stability study is one of the most considerable parameter for safety and economical factors of open pit mines. failure of mines walls can potentially cause loss of lives roads blocking damaging to mining machinery temporarily or permanently halt production and in the worst case scenario closing the mine.

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  • Comparison of Blast-Induced Damage Between Presplit and

    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 and presplit blasting excavation method is studied by using a cumulative blasting damage numerical simulation technology based on the secondary development of the dynamic finite element code LS-DYNA.

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  • PRESPLIT BLASTING PROCEDURES BULL RUN STEAM

    •SINCE ITS DEVELOPMENT in 1958 presplit blasting has become an accepted method of obtaining essentially smooth vertical walls in rock excavation. The usual technique has been to drill a line of vertical blast holes spaced from 1 to 2 ft on centers generally to the depth of the required cut. These holes are loaded with charges made up of 1 -

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  • Explosives Engineers Guide

    2020-4-22 · 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)

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  • PROCEDURES FOR BLASTING

    2015-9-17 · blasting in conjunction with required presplit blasting or for general rock excavation. The Contractor may also elect to use blasting for trenching operations structure excavations and structure demolitions. Permit jobs that involve blasting on State ROW are subject to the same requirements as Department-let contracts.

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