ISRM Suggested Method for In Situ Acoustic Emission Monitoring of the Fracturing Process in Rock Masses

Feng, Xia‐Ting; Young, R. P.; Reyes-Montes, J.M.; Aydan, Ömer; Ishida, Tsuyoshi; Liu, Jianpo; Liu, Hua-Ji

doi:10.1007/s00603-019-01774-z

Cited by 48 publications

(17 citation statements)

References 48 publications

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“…Fraction (%) 58.6 1.9 5.5 2.3 6.9 3.9 20.9 (Gibbons and Ringdal, 2006;Song et al, 2010). Another effective method for event-matching is based on the maximum time difference between the earliest and latest arrivals (Feng et al, 2019). The maximum time acts as a threshold and is usually calculated in terms of isotropy.…”

Section: Mineralmentioning

confidence: 99%

Effect of Velocity Anisotropy in Shale on the Acoustic Emission Events Matching and Location

Wang

Zhang

2022

Front. Earth Sci.

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Accurate source event location is important in fracturing monitoring and characterization. Velocity anisotropy has a great influence on both events matching and events location. Failure to take into account the velocity anisotropy can lead to huge errors in locating events. In this article, we have presented an experimental study on lower Silurian shale from the Sichuan Basin. The experimental observations include ultrasonic measurements, acoustic emissions (AEs) in a three-point bend experiment, and CT scanning of the original sample and the fractured sample. The ultrasonic measurements show that the shale sample has strong velocity anisotropy. Initially, AEs are analyzed using the conventional event-matching method and event location method (Geiger’s method), and the detected events are compared to the X-ray image of the fracture. Event-matching aims to obtain AE signals from the same source event and thus assists in selecting valid AE signals that come from the same source and are received by at least four sensors, to determine the location of the source. Although many reliable signals are obtained by isotropic event-matching, fewer sources were located than expected, and the event location results did not match the fracture distribution. To address this problem, an improved event-matching method is proposed using a stricter matching threshold based on directional velocity rather than a single threshold same for all directions. In addition, we propose an improved Geiger’s method using the anisotropic velocity model. The new methods located more sources that better match fracture distribution than the results of the isotropic method. We have concluded that both event-matching and the source location of the fracturing are largely influenced by velocity anisotropy, and thus in practice, the velocity anisotropy information obtained from various measurements (e.g., laboratory measurements, well logs, VSP, and velocity analysis of reflected seismic surveys) should be involved in both processing procedures. This study can be useful to provide some background for monitoring and predicting dynamic geo-hazards in relation to the AE method.

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Section: Mineralmentioning

confidence: 99%

Effect of Velocity Anisotropy in Shale on the Acoustic Emission Events Matching and Location

Wang

Zhang

2022

Front. Earth Sci.

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“…Based on the statistical analysis of the detection data of the grouting treatment in the goaf for many years, the transverse wave speed in the hole should be greater than 250 m/s for examining and accepting the quality of the grouting in the goaf of a subgrade [18]. After the grouting, the transverse wave speeds of all the strata exceed 250.0 m/s, indicating that the compactness of all the strata is strengthened after the grouting and that the grouting effect is good [19][20][21][22].…”

Section: Detection and Analysis Of Acoustic Wavesmentioning

confidence: 99%

Integrated Treatment Technology of Storage‐Mining Inclined Goaf under Expressway

Wei-xing

Wang

et al. 2020

Advances in Civil Engineering

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An inclined goaf caused by storage mining is a serious risk to subgrades and pavements. In this paper, effective investigation and detection methods of goafs were discussed considering the project of the Urumqi East Ring Expressway crossing the existing goaf of Zhongxing no. 2 mine. Moreover, by theoretical analysis and a series of field comparative tests, reasonable grouting parameters and the treatment plan were obtained. By comparing the test results of the field and laboratory, the influence of groundwater on the effect of grouting was revealed to reduce the compressive strength of the consolidating objects of the slurry. The high-density resistivity method presented strong anti-interference ability and high accuracy in a depth range of less than 150 m in the investigation of the goaf. The results of the treatment showed that it is necessary to conduct research and analysis from multiple aspects to obtain the best treatment plan of a goaf and ensure the safety of a project.

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“…Acoustic emission is a important physical phenomenon with a large number of internal cracks propagation in the failure process of rock mass, and the transient elastic waves are generated by the rapid release of local energy in materials (Shen 2015). As a negative monitoring method, acoustic emission monitoring technology could be used to monitor the micro-fractures in rock mass, and give an effective early warning for rock mass failure (Xiao et al 2016;Feng et al 2019). In this paper, the shear failure process of sandstone was studied by using variable angle shear test device, the failure and acoustic emission characteristics of sandstone under different normal stress conditions were obtained by using PCI-II acoustic emission system.…”

Section: Introductionmentioning

confidence: 99%

Study on Failure Characteristics and Acoustic Emission Characteristics of Sandstone Under Variable Angle Shear

Luo

Guo

et al. 2022

Geotech Geol Eng

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To study the shear damage and failure characteristics of red sandstone under different normal stress conditions, the failure process of sandstone under three different shear angles (50°, 55°, 60°) were studied by using variable angle shear test device. The shear stress-deformation curves and failure characteristics of sandstone were obtained, and the relationships between shear cracks and acoustic emission impact times, amplitude, peak frequency were established. With the increase of shear angle, the normal stress, shear stress and peak shear stress decrease gradually. The development of micro-cracks in the shear plane appear more earlier. The high frequency signal decreases signi cantly, which may have a signi cant corresponding relationship with the rock friction and shear effect. The failure mode of rock changes from plasticity to brittleness. The amplitude changes are concave, and more acoustic emission energy is released at compaction stage and plastic(failure) stage. The rock spalling mainly occur in the penetrating area of main and secondary cracks surrounding the two ends of specimen. The spalling degree was obviously weakened with the increase of shear angle. The results have important guiding value for judging and predicting the instability mechanism of rock engineering.

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ISRM Suggested Method for In Situ Acoustic Emission Monitoring of the Fracturing Process in Rock Masses

Cited by 48 publications

References 48 publications

Effect of Velocity Anisotropy in Shale on the Acoustic Emission Events Matching and Location

Effect of Velocity Anisotropy in Shale on the Acoustic Emission Events Matching and Location

Integrated Treatment Technology of Storage‐Mining Inclined Goaf under Expressway

Study on Failure Characteristics and Acoustic Emission Characteristics of Sandstone Under Variable Angle Shear

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