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Drilling patterns - QueensMineDesignWiki

Blasting tunnels (or drifts) is a necessity in all underground mining operations. Drill and blast techniques are the most conventional and common method and is most useful in high UCS and homogeneous rock types albeit slower than other methods. These tunnels are created for many reasons including: Using the excavated space for transport

Special Tunnel Blasting Techniques for Railway Projects

Special Tunnel Blasting Techni ques for Railway Projects 481 q = q1. s t.f. swr. def, kg/m 3 (1) where, q1=specific charge for breaking of rock against a free face in kg/m 3, st = factor for structure and texture of rock, f = rock confinement = 6.5 / A, (1a)

Understanding the connection between blasting and highwall ...

Jan 01, 2019· Jan 01, 2019· The six controlled blasting techniques that will be discussed are (1) line drilling, (2) trim blasting, (3) buffer blasting, (4) smooth wall blasting, (5) air decking, and (6) presplitting. There are a number of uncommonly used controlled blasting techniques. These techniques work efficiently in specific situations.

(PPT) Study and Quantification of Tunnel Works by drilling ...

• To study various techniques, different types of drilling patterns, blasting techniques, explosive requirements, work procedures for various tunneling activities, boring of tunnel through TBM and safety measures to be adopted during tunnel excavation works etc. • Quantification of major items to be executed for the excavation of shaft and ...

Chapter 11 SPECIALIZED BLASTING TECHNIQUES

blasting of cornices increases efficiency, boring holes along the presumed tension line exposes the ava-lanche blaster to considerable danger. Safety in borehole blasting depends critically on: 1. The blasting crews ability to judge correctly the safe working line. techniques for working with this high explosive (See Chapter 5 - Detonating Cord)..

Drill and Blast Tunneling Practices

Drill and Blast Tunneling Practices Gerhard Girmscheid1 and Cliff Schexnayder, F.ASCE2 Abstract: High-performance drill and blast methods for tunnel construction require that each of the individual working elements that constitute the construction process are optimized and considered as a system of sequential and parallel activities.

PROCEDURES FOR BLASTING

in blasting safety and blasting techniques, and are available to provide assistance during all phases of the blasting operations. Prior to blasting the Contractor shall submit a written blast plan to the Engineer for conditional approval. The Engineer will forward the blast plan to the

Tunnels ppt - SlideShare

Jan 26, 2017· • The largest tunnel in ancient times was a 4,800-foot- long, 25-foot-wide, 30-foot-high road tunnel (the Pausilippo) between Naples and Pozzuoli, executed in 36 B.C. • In 1681 gunpowder was first used for blasting the tunnels. First time the …

Tunnel blasting techniques in difficult ground conditions ...

The quality of tunnelling can be improved by proper blast design which takes into account the rock mass conditions. The effects of different rock mass properties on tunnel blast performance need to be assessed. The strength of the formation and joint orientation critically affected fragmentation and overbreak in a model study of blasting. Similar effects were noted in situ when the performance ...

Tunnels ppt - SlideShare

Jan 26, 2017· • The largest tunnel in ancient times was a 4,800-foot- long, 25-foot-wide, 30-foot-high road tunnel (the Pausilippo) between Naples and Pozzuoli, executed in 36 B.C. • In 1681 gunpowder was first used for blasting the tunnels. First time the ventilation system for tunnel was developed in 1927 in Holland tunnel. 5. • In 1952 James . S.

controlled blasting techniques – Mining and Blasting

Dec 21, 2010· controlled blasting techniques December 21, 2010 by PARTHA DAS SHARMA. ... Tagged blasting, coal mines, control of ground vibration, controlled blasting techniques, mines, tunnel blasting | Leave a comment. April 20, 2009 by PARTHA DAS SHARMA. Ground Vibration Problem in Openpit Mega Blast.

Tunnelling - SlideShare

Nov 22, 2014· The tunnel powerpoint ishict. Tunnel making methods and tunnel boring machine ... Fire-setting is an alternative to blasting. In this technique, the tunnel wall is heated with fire, and then cooled with water. ... Better understanding of ventilation techniques Awareness of new safety and environmental legislation. 31.

Techniques of Controlled Blasting - SlideShare

Dec 17, 2009· 4. 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 …

PPT – TUNNEL CONSTRUCTION PowerPoint presentation | free ...

Carpal Tunnel Syndrome - Carpal tunnel syndrome is a common disorder that causes pain, numbness, tingling, and weakness in the hand and wrist. It occurs when there is a high amount of pressure within the wrist on a nerve called the median nerve. This median nerve provides sensation to the thumb, index, and middle fingers, and half of the ring finger.

Techniques of Controlled Blasting - SlideShare

Dec 17, 2009· 4. 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.

Drill and Blast Method - rail system

Drill and blast method is mostly used method for the excavation throughout the world. The method can be used in all types of rocks and the initial cost is lower than the mechanical method like TBM. This tunneling method involves the use of explosives. Compared with bored tunneling by Tunnel Boring Machine, blasting generally results in higher ...

(PDF) Drilling and blasting as a tunnel excavation method

The blasting sequence in a tunnel or drift always starts from the "cut", a pattern of. holes at or close to the center of the face, desi gned to provide the ideal line of deformation. The ...

Drilling and Blasting - an overview | ScienceDirect Topics

Jan 01, 2012· Jan 01, 2012· A disturbed zone surrounding a tunnel is related to two different techniques: (1) mechanical boring or tunneling and (2) drilling and blasting method. A disturbed zone by drilling and blasting is much larger than that by mechanical tunneling such as the tunnel boring machine (TBM technique), as summarized in the chapter: Single-Hole Blasting in ...

Tunnel Construction Methods and ... - Mining and Blasting

Jul 27, 2011· Tunnel Construction Methods and their comparison . 1. Introduction – This paper gives a general description of the tunnelling techniques such as cut and cover, drill and blast, bored tunnelling and sequential mining construction, reviewed for possible use in various projects. A summary of environmental merits and demerits associated with these methods are also given.