• Drill and Blast Method

    This tunneling method involves the use of explosives. Compared with bored tunneling by Tunnel Boring Machine, blasting generally results in higher duration of vibration levels. The excavation rate is also less than TBM (usually 3 to 5m a day). The typical cycle of excavation by blasting is performed in the following steps: Drilling blast holes and loading them with explosives. Detonating the ...

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  • Tunnel Support Design

    Tunnel Support Design Summary Summary • Projectspecific ground characterization • Compatible excavation methodology –Hard rock tunnel: rock mass discontinuities, strength and abrasion –Softground tunnel: continuous face and periphery support/ GW control / monitoring • Contingency –Risk Mitigation measures: presupport / ground treatment/ temporary invert support

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  • Chapter 8 BLAST DESIGN

    Blasting analysis next becomes a function of the energy factor, explosives cost, fragmentation results, and subsequent production. Proper energy distribution is important in obtaining the desired fragmentation and movement of the bottom or toe portion of the shot. Energy distribution becomes an important factor when wet holes are encountered, as cartridged explosive products must be smaller ...

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  • (PDF) Drilling and blasting as a tunnel excavation method

    For most typical tunnel blasting, the. powder factor varies between and 5. kg/m3. The powder factor can vary. from 1 kg/m3 in a tunnel with an. opening size greater than 30 m2 to. more than 3 ...

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  • Underground Construction (Tunneling)

    A tunnel is "an excavation beneath the surface of the ground, the longer axis of which makes an angle not greater than 20 degrees to the horizontal." A shaft is "(1) a passage made from the surface of the ground to a point underground, the longer axis of which makes an angle greater than 20 degrees to the horizontal; or (2) a pit in which ...

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  • controlled blasting techniques – Mining and Blasting

     · controlled blasting techniques December 21, 2010 by PARTHA DAS SHARMA. Modifiion of Blasting Techniques as per Geological Conditions of Strata . View this document on Scribd. Posted in blasting, explosives, mining | Tagged blasting, blasting techniques, controlled blasting techniques, mining | Leave a comment. September 2, 2009 by PARTHA DAS SHARMA. Techniques of Controlled Blasting.

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  • Blasting_safely_with_proper_

    View Blasting_safely_with_proper_ from HUM MB21 at Northern Illinois University. Blasting safely with proper techniques Module one • The most important responsibility of the blaster

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  • TUNNELS, SHAFT AND DEVELOPMENT HEADINGS BLAST DESIGN

    This multiple face technique was used in the H3 highway tunnels in Hawaii. A by (12 by 18ft) center drift was excavated first and supported at the final tunnel perimeter with bolts and shotcrete. Subsequent side slash and center cut sections were then excavated and supported in the sequence shown below.

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  • 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 Engineering Geology Section, Geotechnical Engineering Bureau for review and written comment. After approval ...

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  • Techniques of Controlled Blasting

    Using millisecond delay sequence and use of inhole delays in decks: boxshadowdwn Delay blasting (with millisecond delays) permits to divide the shot into smaller charges, which are detonated in a predetermined millisecond sequence at specific time intervals. boxshadowdwn Millisecond delay initiation of the explosive charge is a technique used in most open pit, quarry, tunnel and underground ...

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  • Tunnel Construction Techniques And Methods Ppt PowerPoint ...

    Presenting this set of slides with name tunnel construction techniques and methods ppt PowerPoint presentation ideas layouts pdf. The topics discussed in these slide is tunnel construction techniques and methods. This is a completely editable PowerPoint presentation and is available for immediate download. Download now and impress your audience. Your ideas deserve the best accessories. Our ...

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  • Blasting

    View Blasting from SEA at Saint Louis University, Baguio City Main Campus Bonifacio St., Baguio City. BLASTING TECHNIQUES (TE6) Chapter 1 Introduction to Blasting • Blasting is

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  • 5 Explosives and blasting

    Blasting gelatin This is the most powerful explosive containing 92% NG and 8% Nitrocellulose (NC) which contains % nitrogen. Chalk, zinc oxide, air bubbles, acetone etc. are added to make the composition suitable for blasting purposes. Semi gelatin These are also termed as low NG, or high AN explosives due to the fact ...

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  • Pioneering drill+blast work in Hong Kong

     · The technique was first used by the Gammon Nishimatsu JV in development association with Orica on the JV's West Island Line metro extension contract and later by the John HollandLeighton JV on a contract for the South Island Line rail link project. Paul Grad introduces the technique and its appliion in meeting strict noise and vibration criteria for drill+blast excavation in Hong Kong (1 ...

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  • Geotechnical considerations in tunnel design and contract ...

    excavating equipment and techniques and for the highest possible rates of advance. Unfortunately, many of the contractual practices and the attitudes of owners, engineers and contractors which can still be found on many underground projects around the world are more appropriate to the more leisurely days of hand tunnelling. Operating a multiboom jumbo in a drill and blast tunnel or a high spe

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  • Blasting In Mining Ppt

    Introduction drilling and blasting are the most widely adopted excavation techniques for mining and civil blasting results in ground shock and vibration which may cause damage to the surrounding structures such as buildings, bridges, dams. Read More. Rock Blasting Ppt Xpowerpoint. view and download powerpoint presentations on rock blasting powerpoint presentations .

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  • TUNNELS, SHAFT AND DEVELOPMENT HEADINGS BLAST DESIGN

    This multiple face technique was used in the H3 highway tunnels in Hawaii. A by (12 by 18ft) center drift was excavated first and supported at the final tunnel perimeter with bolts and shotcrete. Subsequent side slash and center cut sections were then excavated and .

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  • (PDF) Rock Blasting Technique Mining Engineering ...

    Structure geology (fissure, joint, bedding plane, folliation) Rock Blasting Technique – Mining Engineering Department Rock Rippability Classifiion (Franklin, Broch Walton, 1971) Rock Blasting Technique – Mining Engineering Department Criteria for Blasting Succesfull • The production target is reached (ton/day or ton/month) • Efficient use of explosives are expressed in the .

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  • Ventilation System in Tunnel during Construction Works ...

    tunnel during construction to provide good environment for tunneling works. 1. Safe and health in tunnelling works In tunnelling works comprising drilling, blasting, excavation, shotcreting and mucking, appropriate measures are absolutely necessary to secure safe and healthy working environment. The ventilation system is the most effective method to settle the problem on the dust, smoke and ...

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