1、英文原文Efficient mine microseismic monitoringMaochen GePennsylvania State University, University Park, PA 16802, USAAbstract:During the past 20 years, the microseismic technique has grown from a pure research means for rockburst study to a basic industrial tool for daily safety monitoring at rockburst-
2、prone mines. This article examines the important issues for efficient mine microseismic monitoring programs. The key technical issues for such a program are discussed from three aspects: monitoring planning, data processing, and microseismic event location. An efficient monitoring program would be i
3、mpossible without a firm commitment of the mine management. Issues related to the management and mine operations are discussed, including monitoring program integration, efficient use of microseismic data, and the benefit of monitoring programs for mine safety and productivity.Keywords: Microseismic
4、; Rockburst; Source location; Ground control; Mining1. IntroductionRockbursts and coal bumps are sudden and violent releases of energy stored in rock masses and geological structures. They have been a persistent threat to mine safety, causing catastrophic failures of mine openings, paralyzing mining
5、 operations, damaging mining equipment, and posing a severe safety threat to underground workers. In 1958, a rockburst at the Springhill Coal mine in Nova Scotia claimed 75 lives. In the U.S., a total of 100 rockburst-caused fatalities were reported in the last 60 years (Blake and Hedley, 2003).The
6、energy released by a rockburst can be staggering. In 1995, a rockburst with a local magnitude of 5.2 ML was recorded at the Solvay trona mine, Wyoming, when an entire 1000 m 2000 m panel collapsed. The US coal mining industry has experienced bumps since the 1920s, with magnitudes up to 4.5 (Blake an
7、d Hedley, 2003).The technique that is widely used for studying rockburst activities is the microseismic monitoring technique. The technique utilizes signals generated by the material to study fracture/failure processes. The real time monitoring capability of the microseismic technique, in terms of e
8、vent source location, magnitude and source mechanisms, makes it an ideal tool for studying mine seismicity and related ground control problems.The phenomenon of the emission of micro-level sounds by stressed rocks was first discovered in the late 1930s by two U.S. Bureau of Mines (USBM) researchers,
9、 Obert and Duvall, when they carried out sonic studies in a deep hard rock mine (Obert, 1975). In the early 1960s, South African researchers began to utilize this phenomenon to study the rockburst problem associated with deep gold mines (Cook, 1963). This early study convincingly demonstrated the fe
10、asibility of the rockburst location by the microseismic technique, the central element of mine microseismic monitoring.In the middle of the 1960s, the USBM started a major research program in order to make the microseismic technique an efficient tool for mine safety monitoring. The hardware and soft
11、ware developed from this program, as well as the research and field tests carried out during this period, laid the foundation for the industrial use of the microseismic technique (Leighton and Blake, 1970 and Leighton and Duvall, 1972).From the middle of the 1980s to the early 1990s, severe rockburs
12、t problems occurred spontaneously in Canadian mines. Over 20 rockburst-prone mines installed microseismic systems for daily monitoring purpose. From the late 1980s to the 1990s, large-scale rockburst research was carried out in Canada, sponsored by the Canadian federal government, the Ontario provin
13、cial government, and major mining companies. This research fundamentally changed the role of the microseismic technique in the Canadian mining industry. It is no longer a pure research tool, but the basic monitoring means for mine safety and ground control.This article examines the important issues
14、for efficient mine microseismic monitoring programs. The discussion is carried out from three aspects: monitoring planning, data processing, and microseismic event location. Although the focus of this paper is the technical issues, it is important to note that an efficient monitoring program would b
15、e impossible without a firm commitment from the mine management. For this reason, we will also discuss issues related to the management and mine operations, including monitoring program integration, efficient use of microseismic data, and the benefit of an efficient monitoring program for mine safet
16、y and productivity.2. Planning and optimization of monitoring systemsCareful planning is the foundation for establishing an efficient monitoring program and has a profound impact on the systems long-term performance. There are three important issues to be resolved at this stage: engineering assessment of monitoring objective and monitoring condition; determination of the monitoring system size (number of channels); and optimization of the sensor array layout.
