Overbreak and Underbreak in Underground Openings Part 1: Measurement using the Light Sectioning Method and Digital Image Processing

Abstract

Quick, simple, reliable, and inexpensive measurements of overbreak and underbreak are needed for proper evaluation of tunnelling by the drill and blast method. Problems causing rock damage can be identified and remedied while the work is still in progress. The measurements are also useful in identifying causes of overbreak and overbreak, and in helping to settle contractual disputes relating to payment for replacement concrete and secondary blasting of 'tights' (zones of underbreak). A newly developed method to measure underbreak and overbreak is presented here. The light sectioning method (LSM) uses a radial sheet of light to define the tunnel profile. An image of the final tunnel profile is acquired and digitized, using digital image analysis. This profile is superimposed over the design profile, and from this zones of overbreak and underbreak are identified, quantified, and presented graphically.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Blasting Assessment; Digital Image Processing; Overbreak; Tunnel Profiling; Tunnelling; Underbreak; Digital Signal Processing; Rock Drilling; Rock Mechanics; Light Sectioning Method (LSM)

International Standard Serial Number (ISSN)

0960-3182

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1996 Springer Netherlands, All rights reserved.

Publication Date

01 Dec 1996

Link to Full Text

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