Blasting a presplit in Granite - YouTube
19-02-2017 · This was one of the most rocky home sites that Ive ever blasted, more than 50 individual blasts, 60 truck loads of hard Granite. This video gives a brief lo...
Understanding the connection between blasting …
01-01-2019 · Presplit blasting involves drilling a single row of holes along the back of the final excavation zone . Unlike smooth wall blasting, the presplit holes are fired on the first delay of the production blast. The presplit technique is the most commonly used controlled blasting technique for surface operations. 3.
(PDF) Optimizing Presplit Blasting for …
Presplit blasting is commonly practiced in open pit mines to create shear planes on in situ rock slope to ensure pit wall stability, and also protect nearby structures against blast damage.
smooth blasting presplit - benb-bennekom.nl
Presplit blasting can reduce vibration and back impact induced by cast blasting, thus resulting in a smooth bench slope. To design reasonable presplit blasting parameters, this research investigated the formation of presplit faces based on the explosion mechanics and revealed the cracking mechanism of presplit blasting.
Drilling and blasting - Wikipedia
Drilling and blasting is the controlled use of explosives and other methods such as gas pressure blasting pyrotechnics, to break rock for excavation.It is practiced most often in mining, quarrying and civil engineering such as dam, tunnel or road construction.The result of rock blasting is often known as a rock cut.. Drilling and blasting currently utilizes many different varieties of ...
Directional presplit blasting in an innovative no …
Directional presplit blasting (DPB) technology for an innovative no-pillar mining approach is introduced. First, a mechanical model is established to analyze crack initiation and …
PROCEDURES FOR BLASTING
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 stone that involve blasting on State ROW are subject to …
A REVIEW OF THE DESIGN CRITERIA AND PRACTICAL ASPECTS OF ...
Blasting of weak, highly fissured ground requires a more conservative design than blasting in tough massive rock. Blasthole patterns and charge loads will therefore change appreciably with the rock properties encountered. Perimeter blasting techniques are therefore more costly than re-designed production blasting because
A better way to presplit - Mining & Construction …
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 Circulation (RC) option for in-pit grade control.
Blasting and Explosives Quick Reference Guide 2010
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)
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
Deep-hole pre-split blasting mechanism and its …
01-12-2013 · The blasting boreholes use continuous couple charging method in forward direction, once-charging and blasting with short delay. The trial uses the Class-2 coal mine permissible emulsion explosive, the explosive package dimension is: diameter×length=∅50 mm×580 mm, and a diameter of ∅63 mm PVC drivepipe has been used to put the explosive into the blasting hole.
PRESPLITTING ROCK IN THE PRESENCE OF A STATIC STRESS FIELD
normal blasting procedures. It was believed that the inability to presplit in a horizontal direction underground was a direct consequence of the static stress conditions. If the in situ stress is due primarily to the weight of the overburden, the vertical
DW Drilling & Blasting, LLC. - Services
At DW Drilling & Blasting, LLC we pride ourselves in our presplit projects, we use various products to produce clean, low maintenance, safe cuts for a good appearance that will last decades. presplit …
CN101441055A - Presplit blasting method - …
Presplit blasting method Download PDF Info Publication number CN101441055A. CN101441055A CNA2008100802967A CN200810080296A CN101441055A CN 101441055 A CN101441055 A CN 101441055A CN A2008100802967 A CNA2008100802967 A CN A2008100802967A CN 200810080296 A CN200810080296 A CN 200810080296A CN 101441055 A CN101441055 A CN 101441055A …
Summary of Surface Blasting and Damages with …
While presplit blasting was beneficial, to improve stability of the final face requires proper design of all the blasts, especially those directly in front of the presplit face. Comparison of Blast-Induced Damage between Presplit and Smooth Blasting of High Rock Slope by Hu et al. (2013)
Design and Application of Blasting Parameters for ...
The blasting parameters and hole spacing were optimized. Moreover, the study illustrated the dynamic evolution of the strain and the complex fracture network in a blasted rock mass under the synergistic action of dynamic and static loads. The findings are expected to provide guidance on deep-hole presplit blasting for breaking rocks. 2.
Case Study Cost Reduction in Wall Control Blasting
configuration working on 2m flitches after blasting on 5m benches. Presplit blasts are carried out in advance of trim blasting. The 115mm diameter holes are drilled over two benches (10m), with the top bench drilled at the design wall angle and the bottom bench drilled 5 degrees steeper to allow for drill mast access. A range
pre-splitting | Encyclopedia.com
11-08-2020 · 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.