Seismic Coal Exploration (eBook)

In-Seam Seismics

L. Dresen, H. Ruter (Autoren)

eBook Download: PDF

2013 | 1. Auflage
446 Seiten
Elsevier Science (Verlag)
978-1-4832-8706-5 (ISBN)

Infos

The efficient mining of hard coal in deep coal mines using highly mechanized longwall techniques requires information on the geological structure ahead of the operating face. Even minor tectonic faults with throws of only a few metres mean a loss in productivity, as they present severe working problems for underground mining equipment. Because investment costs to install a mechanized face are high, 'insurance' in the form of spare capacity by both machine shifts or spare faces is uneconomic. Thus, to reduce mining costs it is essential to delineate the geology prior to mining. Today, the only effective geophysical tool to detect and to map minor faults in front of the coal cutter is in-seam seismics using channel, or so called seam waves. The techniques are well established and successfully applied for more than two decades.

In-Seam Seismics covers the entire range of elementary and advanced topics in mathematics, physics and data processing of dispersive channel waves. The results of analogue and numerical modelling provide a thorough understanding of transmission, reflection, recording and interpretation of seam waves and coal seam disturbances. Fire damp proof instrumentation, target orientated underground layouts, processing and interpretation of real data impart the state-of-the-art of in-seam seismics. Selected and well-rounded case histories complete the presentation of in-seam seismics. They can help the mining engineer to come to a decision to plan and to apply in-seam seismics in case of underground mining problems.

A clear text, only formulae which are necessary, many carefully designed figures, an extended list of references and a lucid index make it easy for the reader to get acquainted with seam waves or to promote the technique of in-seam seismics.

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The efficient mining of hard coal in deep coal mines using highly mechanized longwall techniques requires information on the geological structure ahead of the operating face. Even minor tectonic faults with throws of only a few metres mean a loss in productivity, as they present severe working problems for underground mining equipment. Because investment costs to install a mechanized face are high, "e;insurance"e; in the form of spare capacity by both machine shifts or spare faces is uneconomic. Thus, to reduce mining costs it is essential to delineate the geology prior to mining. Today, the only effective geophysical tool to detect and to map minor faults in front of the coal cutter is in-seam seismics using channel, or so called seam waves. The techniques are well established and successfully applied for more than two decades.In-Seam Seismics covers the entire range of elementary and advanced topics in mathematics, physics and data processing of dispersive channel waves. The results of analogue and numerical modelling provide a thorough understanding of transmission, reflection, recording and interpretation of seam waves and coal seam disturbances. Fire damp proof instrumentation, target orientated underground layouts, processing and interpretation of real data impart the state-of-the-art of in-seam seismics. Selected and well-rounded case histories complete the presentation of in-seam seismics. They can help the mining engineer to come to a decision to plan and to apply in-seam seismics in case of underground mining problems.A clear text, only formulae which are necessary, many carefully designed figures, an extended list of references and a lucid index make it easy for the reader to get acquainted with seam waves or to promote the technique of in-seam seismics.

Inhalt

Front Cover 
1 
Seismic Coal Exploration: In-Seam Seismics 4
Copyright Page 
5 
Table of Contents 
6 
Acknowledgements 12
CHAPTER 1. Introduction 14
1.1. Overview 14
1.2. Coal mining concerns 14
1.3. Typical geologic disturbances 17
1.4. Geological sequences with seams as channels of lower seismic velocities 18
1.5. Procedures in fault detection 22
1.6. In-seam seismic activities worldwide, a general overview 23
CHAPTER 2. Physics of Channel Waves in Coal Seams 28
2.1. Introduction 28
2.2. Seam waves as a result of interfering body waves 29
2.3. Dispersive wave trains, phase and group velocity 37
2.4. Dispersion curves 46
2.5. Attenuation of channel waves in coal seams 70
2.6. Reflection and transmission of Love channel waves at faults and seam ends 82
2.7. Anisotropy of coal seams 95
2.8. Generation of seam waves 97
2.9. Sensitivity curves 104
CHAPTER 3. Data Processing 108
3.1. Introduction 108
3.2. Preprocessing 108
3.3. Analysis 112
3.4. Imaging (mapping) 135
CHAPTER 4. Analogue and Numerical Modeling 158
4.1. Introduction 158
4.2. Analogue model techniques 159
4.3. Numerical methods 170
4.4. Results of numerical and analogue modeling 187
4.5. Conclusions drawn from the model seismic investigations for the in situ application of the in-seam seismic method 289
CHAPTER 5. Instrumentation 292
5.1. Introduction 292
5.2. Conditions for instrumentation in a coal mine 293
5.3. Requirements for the measuring instruments 297
5.4. Examples of seismic equipment 298
5.5. Wave sources 308
5.6. Receivers 326
CHAPTER 6. Data Acquisition 338
6.1. Introduction 338
6.2. Transmission surveys 339
6.3. Reflections surveys 342
6.4. Wave sources and receivers 356
6.5. General survey operations 360
CHAPTER 7. Case Histories 366
7.1. In-seam seismic surveys in Australian coal mines 366
7.2. In-seam seismic surveys in the U.K. 369
7.3. In-seam seismic surveys in Germany 382
REFERENCES 410
SUBJECT INDEX 434

Produkt-Details

• Erscheint lt. Verlag: 22.10.2013
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Geowissenschaften ► Geologie
• Themenwelt: Naturwissenschaften ► Geowissenschaften ► Geophysik
• Themenwelt: Naturwissenschaften ► Physik / Astronomie
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Bergbau
• Themenwelt: Wirtschaft
• ISBN-10: 1-4832-8706-8 / 1483287068
• ISBN-13: 978-1-4832-8706-5 / 9781483287065