Introduction

Dresen, L.; Rüter, H.

doi:10.1016/b978-0-08-037226-6.50005-6

Cited by 3 publications

(3 citation statements)

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“…Channel waves are shaped by reflection at strata boundaries, seam thickness and consequent interference, and other seam parameters; thus, they carry substantial information about the coal seams. The thickness and other parameters of the coal seam can be calculated using the dispersion curves of channel waves (Wang et al 2012;Dresen and Rüter 2013;Ji et al 2020). When channel waves encounter geological anomalies in coal seams, they reflect or scatter, and this property can be used to detect such structures (Buchanan et al 1981;Pant et al 1992;Teng et al 2019;Guo et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Detection of geological anomalies in coal mining working faces using a scattered-wave imaging method

Zhang

Cai

Liu

et al. 2023

J Petrol Explor Prod Technol

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A concealed geological structure encountered during the excavation of a coal working face could connect the working face to high-pressure water in limestone strata, which can result in a serious or catastrophic water inrush accident. However, existing geophysical detection methods used to ensure the geological safety of working faces cannot detect small geological anomalies reliably. Based on the generalized theory of scattered waves, we have developed a novel and superior scattered wave imaging method for the detection at the roadway lateral wall, capable of wave vector extraction and multiwave imaging. In this method, the waves scattered from a geological anomaly can be dynamically and accurately extracted by the polarized filter function during the mapping processes of common scattering point (CSP) gathers. A numerical simulation was performed to study the seismic wave response characteristics of a small collapse column in a coal working face. The P and channel waves of the model were extracted and imaged using the novel imaging method. A field study of three-component seismic detection was performed in the Xuzhuang Coal Mine, demonstrating that the joint imaging of body and channel waves can detect small drop faults invisible to channel wave imaging alone. These results indicate that the proposed method can effectively image anomalous bodies on working faces in complex and noisy mine wavefields using multiwave information, providing a new approach for the reliable and timely detection of hazardous geological features hidden in working faces.

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Section: Introductionmentioning

confidence: 99%

Detection of geological anomalies in coal mining working faces using a scattered-wave imaging method

Zhang

Cai

Liu

et al. 2023

J Petrol Explor Prod Technol

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“…As a dispersion parameter, we obtain frequency‐dependent group velocity, which is the velocity of wave transport. Measurement of group velocity from guided wave signals and inversion of the data deliver seam structure, which is crucial for the safety of underground mining (Dresen & Ruter, 1994; Liu et al., 1994; Hu et al., 2018; Zhu et al., 2019). The measurement of observed group velocity is generally performed through multiple filtering and time–frequency analysis (Bhattacharya, 1983; Cox & Mason, 1988).…”

Section: Introductionmentioning

confidence: 99%

Dispersion computation of guided waves in a layered transversely isotropic elastic medium sandwiched between two half‐spaces

Bhattacharya

2023

Geophysical Prospecting

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A transversely isotropic (TI) elastic medium with vertical axis of symmetry (VTI) is considered. We obtain dispersion equations in real terms for guided Love and Rayleigh waves in a VTI medium consisting of horizontal layers sandwiched between two half‐spaces by brief modifications of the available literatures on dispersion equations in elastic layered media through transfer matrix. To illustrate the applicability, dispersion curves of guided waves are computed for 3‐layered and 5‐layered symmetric models with a VTI coal seam in the middle. Airy phase is marked by a minimum or maximum of group velocity in a dispersion curve and this phase is important to get seam structure for mining safety. For the first 3 modes, the effect of VTI Thomsen parameters γ, ε and δ of a coal seam on frequency (fA) and group velocity (UA) of Airy phase is similar in 3‐ and 5‐layered models. For guided Love waves, fA and UA have nearly an uniform increase with increase of γ. For guided Rayleigh waves, increase of ε causes fA and UA to increase; while increase of δ causes fA and UA to decrease.This article is protected by copyright. All rights reserved

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“…Therefore, high-resolution underground active-and passive-source seismic surveys may be good alternatives to expensive conventional large-scaled active-source seismic surveys from the surface to enhance geological models of the subsurface or support drilling procedures. While underground reflection seismic imaging in the form of In-Seam Seismic (e.g., Dresen & Rüter, 1994;Schott & Waclawik, 2015), Horizontal Seismic Profiling (HSP) (e.g., Bohlen et al, 2003;Dickmann, 2005), or conventional reflection seismic (e.g., Orlowsky et al, 2018) are common methods for the identification of geological structures from underground mines and tunnels, the utilization of passive-source seismic interferometry (PSI) is rather unknown for use in underground mines. To date only Olivier (2015) approached the application of PSI in an underground mine with respect to microseismic monitoring to improve mine safety.…”

Section: Introductionmentioning

confidence: 99%

Active and Passive-Source Underground Seismic Data Acquisition

2022

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As part of the European research project Seismic Imaging Techniques for Mineral Exploration (SIT4ME), in-mine seismic active-source and continuous noise measurements were performed within an underground mine gallery of a former radioactive waste repository -the Asse II salt mine (Lower Saxony, Germany) to investigate its geological conditions. Inspired by recent underground active-seismic surveys in the Cote Blanche salt mine and former In-seam seismic surveys in the German hard-coal district of the Ruhr area, we apply conventional exploration and processing methods to an image of the subsurface. Among others, these include data sorting, bandpass filtering, normal moveout correction, static correction and depth (distance) conversion. To process the passive seismic data, we perform an illumination diagnosis for the retrieval of body-wave arrivals and apply passive-source seismic interferometry by cross-correlation (PSI CC ) on noise data dominated by S-waves. We show that active-source seismic measurements can be used from underground mine galleries for the identification of geological structures. Furthermore, we demonstrate that PSI CC can be used to produce virtual-source underground seismic surveys resembling an active-source seismic survey.

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Introduction

Cited by 3 publications

References 0 publications

Detection of geological anomalies in coal mining working faces using a scattered-wave imaging method

Detection of geological anomalies in coal mining working faces using a scattered-wave imaging method

Dispersion computation of guided waves in a layered transversely isotropic elastic medium sandwiched between two half‐spaces

Active and Passive-Source Underground Seismic Data Acquisition

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