Proceedings of the Ninth International Conference on Deep and High Stress Mining最新文献

{"title":"The validity of Es/Ep as a source parameter in mining seismology","authors":"Ig Morkel, Johan Wesseloo, Y. Potvin","doi":"10.36487/ACG_REP/1952_29_MORKEL","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_29_MORKEL","url":null,"abstract":"It is generally accepted that the ratio of energy associated with the S-wave (Es) and P-wave (Ep) is dependent on the focal mechanism (Mendecki (2013). In the mining industry, the ratio of S-wave energy to P-wave energy is regarded as an important indicator of the type of focal mechanism, with the ratio being lower for explosive sources and higher for fault slip (Cai et al 1998, Mendecki, 2013). In pure shear, the Es is considerably larger than Ep (Es/Ep > 20). For the tensile model, Sato (1978) has shown that Ep and Es are approximately equal. Gibowicz et al (1991) and Gibowicz and Kijko (1994) suggest that when Es/Ep   10. Hudyma and Potvin (2010) suggest that for events with Es/Ep < 3, the mechanism is non-shear. \u0000This paper investigates the Es/Ep ratio parameter and how sensitive it is to different seismic service setups. It will achieve this by investigating the consistency of the parameter for three different scenarios.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"32 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120942842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The geotechnical evolution of deep level mechanised destress mining at South Deep","authors":"P. Andrews, R. Butcher, J. Ekkerd","doi":"10.36487/ACG_REP/1952_02_ANDREWS","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_02_ANDREWS","url":null,"abstract":"The South Deep mine is located approximately 45 km south-west of Johannesburg in the Far West Rand goldfield of the Witwatersrand Basin. It is a deep level mine that is actively mining between 2600 m and 3000 m below surface with expectations to mine to 3400 m depth. \u0000South Deep is situated in the geologically unique and renowned Witwatersrand Basin, which is the world’s premier gold region. The South Deep ore body gradually increases in thickness to the west, from approximately two metres at the sub-crop to approximately 120 metres in thickness. The geometry of the Upper Elsburg Reef package, which is the primary economic target, lends it to a fully mechanised mining method. \u0000The main geotechnical challenges to successfully mine the South Deep orebody were to introduce a mechanised massive mining method at depth to destress and then extract the extensive orebody. The destressing method then had to allow a productive method for economic extraction of an essentially low-grade bulk volume orebody. \u0000Several variations of different mining methods have been used to date but all rely on a destressing method to reduce the in situ stresses. Originally the destressing was done conventionally (traditional South African narrow reef gold mining methods). \u0000Since Gold Fields acquired South Deep in 2007, the push for further mechanisation has seen four mining method changes, including: mechanised, low profile, apparent dip destress mining; the introduction of a low profile, horizontal destress method with backfill. The year 2011 saw the introduction of low profile, horizontal destress with 2m wide crush pillars And in 2015, the mine moved to high profile (5.5m high) horizontal destress development with mechanised installation of ground support. Crush pillars were replaced with yield pillars.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123880229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of the Gutenberg-Richter b-values of overlapping seismic clusters with application to Cooke 4 gold mine","authors":"Julius Ketelhodt, Dakalo Ligaraba, R. Durrheim","doi":"10.36487/ACG_REP/1952_25_DURRHEIM","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_25_DURRHEIM","url":null,"abstract":"The b-value of the Gutenberg-Richter frequency-magnitude relationship is an indicator of rock failure processes. Near-real-time analysis of the b-value has the potential to mitigate the risk posed by rockbursts, for example, by adjusting the geometry, sequence and rate of mining; or evaluating the re-entry time following a large seismic event. There are two main approaches to selecting a data set for b-value analysis: (i) select seismic events that fall within polygons or polyhedra associated with particular working places or seismic sources (e.g. a development end, stope or fault); or (ii) select seismic events that occur in the vicinity of each node of a 2D or 3D mesh that covers the entire region of interest. \u0000Challenges include the inevitable trade-off between statistical stability and space-time resolution, and overlaps of clusters of seismic events that arise from different sources. We wrote a Matlab code “Bplot” to conduct numerical simulations to investigate strategies to improve the resolution and reliability of b-value analysis. Bplot was also used to analyse seismicity during the extraction of the shaft pillar at Cooke 4 gold mine. Approximately 450 000 events, recorded from July 2011 to October 2011, were used to map spatial and temporal variations in the b-value. We find lower b-values close to the stope face. We attribute the higher b-value ahead of the stope to the occurrence of numerous small events caused by the fracture of intact rock by high stresses ahead of the mining front; while the relative increase in the number of larger events close to the face is considered to be the result of the growth and coalescence of these fractures.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129985688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2019 status report: Drilling into seismogenic zones of M2.0–M5.5 earthquakes in South African gold mines (DSeis project)","authors":"H. Ogasawara, B. Liebenberg, M. Rickenbacher, M. Ziegler, H. V. Esterhuizen, T. Onstott, R. Durrheim, M. Manzi, S. Mngadi, Y. Yabe, S. Kaneki, E. Cason, Jan-G. Vermeuren, E. Heerden, T. Wiersberg, M. Zimmer, C. Kujawa, R. Conze, G. V. Aswegen, N. Wechsler, A. Ward, S. Enslin, S. Tau, Mavuso Bucibo, DSeis Team","doi":"10.36487/ACG_REP/1952_28_OGASAWARA","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_28_OGASAWARA","url":null,"abstract":"In 2014, a M5.5 earthquake ruptured the range of depths between 3.5 km and 7 km near Orkney, South Africa. The main and aftershocks were very well monitored in the nearfield by dense, surface, strong motion meters and a dense underground seismic network in the deep gold mines. The mechanism of this M5.5 earthquake was left-lateral strike-slip faulting, differing from typical mining-induced earthquakes with normal-faulting mechanisms on the mining horizons shallower than 3.5 km depth. To understand why such an unusual event took place, the aftershock zone was probed by full-core NQ drilling during 2017-2018, with a total length of about 1.6 km, followed by in-hole geophysical logging, core logging, core testing, and monitoring in the drilled holes. These holes also presented a rare opportunity to investigate deep life. In addition, seismogenic zones of M2–M3 earthquakes were probed on mine horizons that were also very well monitored by acoustic emission networks. This paper reviews the early results of the project.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127060631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of a remote control rock bolting system for narrow seam hard rock mines","authors":"D. O’Connor, T. Sertić","doi":"10.36487/ACG_REP/1952_18_O_CONNOR","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_18_O_CONNOR","url":null,"abstract":"An estimated 90 percent of South Africa’s gold-bearing reefs are less than 1 m thick Joughin (1976). A large mineral resource therefore lies in seams that are becoming increasingly uneconomic to extract because of the grade dilution caused by raising the mining height to suit currently available mechanized mining equipment Harper (2008). A similar situation applies to platinum resources. \u0000Historically in SA, mining of these narrow seams has been carried out by labour intensive methods, with little equipment beyond hand-operated rock drills. However, the arduous and hazardous work environment is becoming increasingly unattractive to both the workforce and mine operators. Globally, major mining companies are striving to increase safety by removing workers from the immediate vicinity of the operations and increasing productivity by better integration of the phases of the regular mining cycle to reduce cycle times Lynch and White (2013). Attaining both objectives requires going beyond mechanization to high degrees of automation and/or remote control of equipment. \u0000These factors present a challenge to South African mine operators and their equipment suppliers as mechanization of the narrow seam, hard rock mining environment has proven difficult with scant success Pickering and Ebner (2006), and Harper (2008). \u0000This paper describes the development of a semi-automated, remote controlled rock bolting system for hard rock mines with a mining height of between 0.9 m and 1.2 m (ULP Project). The rock bolting system required development of fully mechanized, remote controlled rock bolting rig, novel rock bolts and a pumpable, fast-acting resin grout to secure the bolts. \u0000The introduction of systematic rock bolting has resulted in a decrease in rock-related accidents, but the many manual operations required in drill-steel and bolt handling in confined spaces and close proximity to high-powered equipment, has led to increased injuries (particularly hand injuries) to the rock bolting operators Makusha (2015). Remote-control equipment has the potential to mitigate such injuries. \u0000The rock bolter is one component of an equipment suite enabling full mechanization of rock breaking by blasting, clearing broken rock and rock support. Development started in 2012 and the bolting rig has been operating on a platinum mine since 2017. Deployment of further equipment suites is planned for 2019.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127355885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic response to mining the massive ore body at South Deep gold mine","authors":"N. Naicker","doi":"10.36487/ACG_REP/1952_26_NAICKER","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_26_NAICKER","url":null,"abstract":"Mining currently takes place at depths of between 2400 m and 2650 m below surface at South Deep gold mine. The ore body comprises Witwatersrand conglomerates and varies from 1 m to 120 m thick and extends over several kilometres. A mining method, specific to the geometry of the ore body, is utilized and comprises an initial destressing cut followed by massive mining in the destressed shadow. \u0000A high profile stoping (HPS) mining method was introduced to reduce or eliminate many of the mining difficulties experienced with the previous low profile stoping (LPS) method. A system of regional stabilising pillars, together with the placement of backfill is utilized to minimise seismic energy emissions. Improvements to the ground support to mitigate rockburst damage were introduced and further improvements are ongoing. \u0000A mine-wide seismic system comprising 35 sensors is used to monitor seismic activity. Attempts to improve seismic monitoring include velocity calibrations, sensor orientation studies, more accurate determination of the attenuation factor (Q) and batch reprocessing of data to ensure consistency across software versions. \u0000In this paper, the level of seismic activity in relation to the level of production, inclusive of production ramp ups and stoppages, from different sections of the mine, is evaluated. The type and severity of damage to workings is assessed together with a comparison of peak particle velocities at the damage locations. Preconditioning, other rockburst risk mitigation strategies and the sources of seismicity (in particular the role of geological features), are assessed. The seismic hazard for different periods of time is calculated.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128009555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Stoping sequence optimisation at Eleonore Mine based on stress analysis through horizon scale numerical modelling","authors":"L. Bouzeran, M. Pierce, A. Jalbout, M. Ruest","doi":"10.36487/ACG_REP/1952_20_BOUZERAN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_20_BOUZERAN","url":null,"abstract":"The orebody at Eleonore Mine (Eleonore) consists of multiple lenses of narrow thickness. Owing to ground stability issues, the capacity of the support was increased and the mine sequence was changed successfully in 2016. In 2018, mine-scale geomechanical numerical analyses were conducted in the continuum code FLAC3D to better understand the conditions leading to these improvements and further optimise the sequence. Locations of falls of ground and damage, blast hole performance and a micro-seismic database were used to calibrate the model, and different future mining sequences were analysed. The models helped demonstrate that persistent shallow dipping joints subject to high horizontal stress put a lot of demand on bolts in the back of excavation; they are likely to be the main source of energy release as they are sheared peripheral to the top and bottom of the stopes. The narrow-mined width and good rock strength involve limited stope interaction, resulting in highly stressed remnant stopes and limited impact of the sequence.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125302504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large scale testing of surface support","authors":"R. Brändle, R. Fonseca, T. Hangartner","doi":"10.36487/ACG_REP/1952_12_BRANDLE","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_12_BRANDLE","url":null,"abstract":"Ground support for dynamic conditions must be able to withstand the associated loads and deformations and the support scheme must work as a system. In order to prove the suitability of such support systems with high-tensile steel mesh and bolts, and also to analyse their bearing behaviour, a large-scale test setup was commissioned in Walenstadt, Switzerland. On this test rig, it was possible to apply large energies on variable ground support schemes with variable bolt patterns and meshes with a total support area of 3.6 m x 3.6 m. The test site is instrumented by load cells, high-speed video analysis and accelerometers. In this paper the analysis of the load cells, the accelerometers and the high-speed video cameras is given, and results are discussed. It could be shown that a combination of high-tensile steel mesh with a specific bolt pattern can result in high energy capacity surface support. Distribution of the impact loads during the stoping process to the different elements of the bearing support system depends on the strength and flexibility of the mesh and the bolts resistance and his pattern.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132259191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances and applications for automated drones in underground mining operations","authors":"E. Jones, J. Sofonia, Christian Canales Cardenas, S. Hrabar, F. Kendoul","doi":"10.36487/ACG_REP/1952_24_JONES","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_24_JONES","url":null,"abstract":"The development and current state of the Hovermap autonomous flight system in underground and GPS-denied areas is discussed, with examples obtained during the development and early adoption of the system. The current performance of the system and subsequent data interpretation suggest some scenarios in which Hovermap deployment is appropriate and have been proven. The examples focus principally on improving safety through a better understanding of the rock mass behaviour and failure mechanisms commonly encountered in deep and high-stress mining conditions, and from feeding these insights back into the design process. Recent and future developments in the hardware and software platforms and the associated data analytics are also outlined","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122563462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seismic Risk Management practices in metalliferous mines","authors":"Y. Potvin, Johan Wesseloo, G. Morkel, S. Tierney, K. Woodward, D. Cuello","doi":"10.36487/ACG_REP/1952_10_POTVIN","DOIUrl":"https://doi.org/10.36487/ACG_REP/1952_10_POTVIN","url":null,"abstract":"The management of seismic risks in metalliferous mines operating in developed mining countries such as Australia, Canada, Chile and Sweden has been very successful during the last decade. The occurrence and magnitude of large seismic events in deep mines has continued to increase with mining reaching deeper horizons, yet, injuries and fatalities due to rockbursts remain very rare in these countries. \u0000Although there are many common practices used to manage seismic risks in mines, there is no recognised process to do so. In 2017, Newcrest Mining Ltd, in collaboration with the Australian Centre for Geomechanics (ACG), undertook a benchmarking campaign to document the different seismic risk management practices currently implemented in mines which are considered leaders in this area. Data was gathered from 16 mines operating in five countries, experiencing different degrees of seismicity. Analysis of the data from the benchmarking study led to a better understanding of seismic risk management practices applied in the industry. \u0000One of the important outcomes of this project was the development of a flowchart describing in detail a generic seismic risk management process. The process is broken into four different layers of activities: data collection, seismic response to mining, control measures, and seismic risk assessment. \u0000Within each layer of activity, there are a number of components, and within each component, there are a number of practices, which have been benchmarked and are discussed in this paper. \u0000In addition to providing a road map for managing seismicity in underground metalliferous mines, this work enables users to assess their own practices against standard and advanced practices in the management of seismic risks. A full description of the seismic risk management process is available to the mining industry at https://acg.uwa.edu.au/srmp.","PeriodicalId":213743,"journal":{"name":"Proceedings of the Ninth International Conference on Deep and High Stress Mining","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127035855","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}