Review on In Situ Acoustic Emission Monitoring in the Context of Structural Health Monitoring in Mines

Abstract

: A major task in mines and even more in underground repositories for nuclear waste is to investigate crack formation for evaluation of rock mass integrity of the host rock. Therefore, in situ acoustic emission (AE) monitoring are carried out in mines as part of geomechanical investigations regarding the stability of underground cavities and the integrity of the rock mass. In this work, the capability of in situ AE monitoring in the context of structural health monitoring (SHM) in mines and in various geological settings will be reported. SHM pointed out, that the AE network is able to monitoring AE activity in rock with a volume up to 106 cubicmeter and distances up to 200 m (e.g., 100 m × 100 m × 100 m) in the frequency range of 1 kHz to 150 kHz. Very small AE events with source size in approximately centimeter to millimeter scale are detected. The results show that AE activity monitors rock deformation in geological boundaries due to convergence of the rock. In addition, high AE activity occurs in zones of dilatancy stress in homogenous rock. In conclusion in situ AE monitoring is a useful tool to observe instabilities in rock long before any damage becomes visible.

Structural Health Monitoring of Large Structures Using Acoustic Emission–Case Histories

“…There were 28 papers submitted to this special issue, and 14 papers were accepted (i.e., a 50% acceptance rate). A key review paper, authored by Manthei and Plenkars [7], covered AE applications for the SHM of mines and in various geological settings. Of these, underground repositories for nuclear waste are especially significant, and millimeter-size defects were located in a million cubic meter volume, demonstrating in situ AE monitoring is a useful tool to observe instabilities in rock long before any damage becomes visible.…”

A Tilt Sensor Node Embedding a Data-Fusion Algorithm for Vibration-Based SHM

“…The goal of providing early anomaly detection and damage localization is pivotal in SHM [4][5][6][7][8][9]. Compactness and reduced power consumption make microelectromechanical (MEMS) sensors suitable for structural monitoring; also, they can be directly deployed on-structure, all the while allowing for low-cost frameworks and extending electronics life cycle.…”

Mapping lithological boundaries in mines with array seismology and in situ acoustic emission monitoring

“…Since the beginning of last century seismic networks are used to study seismic events in mines (Gane et al, 1946;McGarr, 1971a,b;Spottiswoode, 1989;Gibowicz and Kijko, 1994;Collins et al, 2002;Plenkers et al, 2010). Microseismic and sometimes in-situ Acoustic Emission (AE) monitoring networks are operated in mines worldwide and provide large amounts of data (see Manthei and Plenkers, 2018 for a review).…”

“…To our knowledge, these methods have not yet been applied to mine-scale investigations and picoseismicity, even though, despite the different scales and magnitudes, it is well documented that waveforms of picoseismicity events are well suited for extended waveforms analysis; e.g., source parameter analysis (Dahm et al, 1999;Kwiatek et al, 2011). We test the application of these techniques to high-frequency AE picoseismicity that occurs in a frequency range from 1 kHz up to 200 kHz (Manthei and Plenkers, 2018) on a data set recorded by a sensor network in a salt mine.…”

“…To reduce the amount of stored data, the sensors were equipped with a trigger system for the detection and the recordings of events. The recording time for each trigger is 32.768 ms (Manthei and Plenkers, 2018), allowing the recording of the P-wave and S-wave onsets, necessary for locating the events. A more detailed description of the events and sensors is found in Phillip et al (2015).…”