03 Saftey in Excavation & Blasting.ppt an | PPT

Simple Sloping • Type B - 1:1 450 • Type C - 1½ :1 340 Note :Greater than 20 feet deep shall be designed by ... equipment within 50 feet of loaded holes. Safety Code For Blasting And Related Drilling Operations 57. • Load only those holes intended to be fired in the next round. • Warning signs posted. • Check all holes for depth ...

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Numerical analysis of deep hole multi-stage cut blasting of vertical

Due to the high in situ stress of the deep rock mass and the restraining effect of the surrounding rock, the deep hole blasting of vertical shaft faces the problems of low borehole utilization rate and poor blasting effect. In this regard, this paper proposes a deep hole multi-stage cut blasting technology of vertical shaft. Preliminary engineering practice shows that such cut …

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1926.905

Powerlines and portable electric cables for equipment being used shall be kept a safe distance from explosives or blasting agents being loaded into drill holes. Cables in the proximity of the blast area shall be deenergized and locked out by the blaster.

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JAn 203 1 of 21 Surface Blasting Safety Procedures

• The minimum distance for personnel is 500 feet. • Safe distances will be determined based on conditions for each blast by the Blasting Foreman or designee. Blasting …

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Blasting for Fracturing and Improving the Permeability of Deep, …

To address the problems with deep-hole presplit blasting intended to fracture and improve the permeability of deeply buried, soft, high-gas-content coal seams, a method using a blasthole and a ...

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The Ultimate Guide to Drilling and Blasting

During the Blast. Red Flag Warning: A red flag marks the blast area for everyone's safety. Safe Distance: All personnel must evacuate to a minimum distance of 200 meters from the detonation site. ... Blast hole loading …

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Safe distance for mining blasting

Safe distance for blasting Blasting hazards: blasting earthquakes, air shock waves, scattered debris, toxic gases.

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29 CFR 1926.905 -- Loading of explosives or blasting agents.

(j) Powerlines and portable electric cables for equipment being used shall be kept a safe distance from explosives or blasting agents being loaded into drill holes. Cables in the proximity of the …

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Mechanism of Hard-Roof Rock Burst Control by the Deep-Hole Blasting

In underground coal mines, the deep-hole blasting (DHB) technology is generally adopted for thick hard-roof control. This technology uses the energy released by explosives to weaken the energy ...

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Deep hole liquid carbon dioxide cold explosion method

The invention relates to the technical field of rock breaking, and provides a deep hole liquid carbon dioxide cold blasting method which comprises the following specific steps: (1) designing and calculating drilling and blasting parameters, wherein the parameters comprise aperture, pitch, number of holes, warning distance and quality of used liquid carbon dioxide; (2) determining a …

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30 CFR Part 56 -- Safety and Health Standards—Surface Metal …

In determining the blast area, the following factors shall be considered: (1) Geology or material to be blasted. (2) Blast pattern. (3) Burden, depth, diameter, and angle of the holes. (4) Blasting …

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Experiment Study of Stemming Length and Stemming Material …

Stemming length and stemming materials are crucial factors in blasting design, which affect the sustainability of mining. This study investigates the influence of stemming length and stemming material on rock fragmentation, stemming recoil, and surface strain response through 15 small-scale model blasting tests. The results indicate that when using clay as a …

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Safe distance for mining blasting

Safe distance for blasting Blasting hazards: blasting earthquakes, air shock waves, scattered debris, toxic gases. Blasting must determine the scope and safety distance of blasting hazards, and set up warning and safety protection measures. ① Safe distance for blasting flying stones Blasting type Minimum safe distance for individual flying stones Shallow hole blasting to break …

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CMR-2017 NOTES ON EXPLOSIVE AND …

Deep-hole blasting. – ... the shot-firer shall charge or fire a shot only after sufficient warning is given over the area within a radius of 500 meters from the place of firing ... The distance between the 1st row of holes and …

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Chapter 8 BLAST DESIGN

The term SPACING denotes the lateral distance on centers between holes in a row. The BURDEN is the distance from a single row to the face of the excavation, or between rows in the usual case where rows are fired in sequence. Chapter 8 BLAST DESIGN (Figure 8-2) Staggered pattern (Figure 8-3) Sing (Figure 8-1) Square or rectangular pattern. 114 ...

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Safe Distance between the Deep-Hole Blasting and the Grouting …

And the safety criterion of the PPV of the grouting curtain was 4.84 cm/s. On the in-situ blasting vibration monitoring data, the Sadov's empirical formula was established, and the safe distance between the deep-hole blasting position and the grouting curtain under different maximum single-hole charges was obtained.

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How to Conduct Blasting Operations Safely? [PDF]

Safety Precautions while Blasting. For the safety of workers, red flags shall be prominently displayed around the area where blasting operations are to be carried out. All the workers at the site shall withdraw to a safe distance of at least 200 meters from the blasting site. An audio warning by blowing whistle shall be given before igniting ...

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Clarification concerning allowable drilling distance between …

No activity of any nature other than that which is required for loading holes with explosives shall be permitted in a blast area. 1926.905(k) states: Holes shall be checked prior to loading to …

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Theory and numerical simulation of deep hole cut blasting based …

For deep hole blasting, the original oblique hole cutting method necessitates the explosive to be concentrated at the bottom of the blast hole, making the distribution of the explosive energy unreasonable. ... The distance between the center hole and the face ZY is 250 mm, the length of the charge is 1.21875 m, and the length of the plug is 1. ...

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Long hole charging and blasting

the final swelling void before the full production blasting is started, all these opening methods are followed by initial long-hole production blasting of the closest surrounding holes to enlarge this void. As a general rule, good practice in drilling and charging will include: • Reamed holes, charged and uncharged. • High precision drilling.

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The Ultimate Guide to Drilling and Blasting

Red Flag Warning: A red flag marks the blast area for everyone's safety. Safe Distance: All personnel must evacuate to a minimum distance of 200 meters from the detonation site. Whistle Warning: A shrill whistle is blown …

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(PDF) Coupling Technology of Deep-Hole Presplitting Blasting …

The Datong Mine was a background to study the blast crush zone and drainage influence range following deep-hole blasting with holes laid in coal seams, which resulted in a 24% increase in gas flow ...

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CMR-2017 NOTES ON EXPLOSIVE AND …

Comprehensive notes on Chapter 14 (Explosives and Shotfiring) of CMR 2017. Chapter 14 of Coal Mines Regulations, 2017 deals with provisions regarding Drilling and Blasting. In this blog, notes are made by compiling the …

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Blaster's Training Modules

blasting results or require changes in hole-loading practices. Drilling Methods The components of a drill rig are (1) the rig itself, which supplies the power to mobilize, drill rock, and remove the drill cuttings from the hole; (2) the mounting; (3) the drill steels or drill string; and (4) the

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Key Blasting Parameters for Deep‐Hole Excavation in an …

In the four-hole blasting scheme, the average unit explosive consumption is 1.809 kg/m 3, the average footage of single cycle excavation is about 3.4 m, and the utilization rate of blast holes is up to 92%. From the scenes two empty hole and four empty hole blasting effect data, without changing the total charge and the number of blast holes ...

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DIVISION 1 — GENERAL REQUIREMENTS

(2) The blast hole diameter must not exceed 75 mm (3 in). (3) The bench height to burden ratio must be at least 2 to 1. (4) In respect of blast holes, (a) all blast holes must be effectively stemmed with small crushed aggregate rock or an energy confinement device, and (b) the use of drill cuttings alone does not meet the requirements of ...

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Behind the Boom: How Blasting Works in Construction Projects

Safety is non-negotiable in blasting. Here are the top safety practices that every blasting company—and any contractor working with them—should prioritize: Blast Zones and Barriers: Setting up a clear blast zone is essential. Blasting companies use barriers and signage to keep unauthorized personnel far away from the blast site.

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Application of Long-Distance Drilling and Blasting Technology to …

By comparing the micro seismic activity cloud maps of the three stages of long-distance drilling blasting and roof deep hole blasting before and after the implementation of long-distance drilling blasting, it can be seen that in the initial roof deep hole blasting stage, the micro seismic activity index in front of the mining area reached 0.5.

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Construction Blasting Fundamentals

From a safety perspective, it is important to know how sensitive an explosive is to impact, friction, and heat. ... stringent blast effect control measures, and effective blast area security and warning methods must be evaluated for close-in blasting. ... Large blast holes may be as large as 9 inches or 225 mm. in diameter, while small holes ...

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Mechanism of Hard‐Roof Rock Burst Control by the Deep‐Hole Blasting

The key to prevention of hard-roof rock burst is the modification of thick hard roof by weakening the strata structure. At present, the commonly adopted methods include deep-hole blasting [] and hydraulic fracturing [].The principle of DHB for lowering rock burst risk is to use the energy released by explosives to increase the beddings and fractures of specific strata, weaken their …

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