Proceedings of the Second International Conference on Underground Mining Technology最新文献

{"title":"Rapid automated processing of structural orientation from time-of-flight LiDAR mapping","authors":"James Smith, S. Yee","doi":"10.36487/acg_repo/2035_10","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_10","url":null,"abstract":"The three-dimensional axis mapping (3DAM) method allows rapid capture and orientation of point cloud data to magnetic north in GPS and survey denied environments. From the collected point cloud data, the 3DAM algorithm automates the identification of rock structures and the processing of their orientation into a stereonet format, at the point of data collection, on a timescale measured in seconds. A tool, the Axis Mapper, was created based upon this method and is intended to streamline geological and geotechnical underground mapping of structural orientation data. \u0000The objective of this paper is to compare the precision and speed of capture for the Axis Mapper’s orientation measurement to the most prevalent method of orientation capture in underground mines, the structural compass. \u0000Structural orientation data captured from two case studies—one, at a base metals mine in South America; the second, two mines in Ontario, Canada—were compiled and compared for precision and speed between the Axis Mapper’s 3DAM method and a compass. Additional locations of data captured were planned but could not be collected for this paper. Sources of measurement interference, which could not be mitigated, were present at both case study locations. \u0000The data collected from the case studies suggest that structural orientation captured by the Axis Mapper and compass are within 11° dip direction and 5° dip of each other; except in one discreet example which identified a dip difference of 23°. The Canadian case study suggests the Axis Mapper is up to three times faster at collecting structural orientation data when compared with the compass. The authors consider the conclusions preliminary and non-definitive due to the limited number of collection sites, limited available data, and uncontrolled sources of measurement interference. Additional data collected in controlled settings are necessary to better define the comparative precision and collection speed of the Axis Mapper data.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114757513","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 the mesh clamp and its evaluation","authors":"W. Roach, M. Rataj, B. Darlington","doi":"10.36487/acg_repo/2035_18","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_18","url":null,"abstract":"With mine owners and operators continuously looking to increase development rates and reduce extraction costs, whilst maintaining safety, the need to develop new innovative products has never been in higher demand. \u0000Working with the mining industry, Sandvik has recently developed and released a mesh clamp, which is designed to work with Sandvik’s MD and MDX bolt range. The mesh clamp enables the installation of mesh sheets to be quicker, safer and more cost-effective. \u0000The major challenge of designing the mesh clamp was to keep the design simple whilst still meeting the requirements of installation flexibility and remaining inobtrusive to the surrounding work area. \u0000After several design iterations were laboratory and field tested, a final concept was agreed upon. The systems performance of the mesh clamp and the mesh needed to be evaluated. This required the development of a unique laboratory test rig to simulate the relevant test environment and loading conditions. \u0000Laboratory test results proved that the mesh clamp is stronger than the 100 × 100 × 5.6 mm welded wire mesh. The mesh and mesh clamp arrangements were tested until failure occurred, at full mesh load capacity, where the mesh and mesh clamp performed well as a system to absorb a minimum of 50 kN with up to 250 mm of vertical mesh displacement.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121249789","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":"Can new technologies shake the empirical foundations of rock engineering?","authors":"D. Elmo, D. Stead, Beverly Yang, R. Tsai, Yaniv Fogel","doi":"10.36487/acg_repo/2035_01","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_01","url":null,"abstract":"The past decade has witnessed an increasing interest in applications of machine learning (ML) to solve mining and geotechnical problems. This is largely due to an increased use of high-level programming languages, development of user-friendly and open source ML libraries, improved computational power, and increased cloud storage capacity to handle large and complex data sets. The benefit of incorporating ML in rock engineering design are apparent, including the reduction in the time required to sort and characterise field data and the capability to find mathematical correlations between overly complex sets of input data. However, when applied to geotechnical engineering, the question arises as to whether ML can truly provide objective results. In geotechnical engineering, where the medium considered is typically heterogenous and only limited information is spatially available, experience and engineering judgement dominate the early stage of the design process. However, experience and engineering judgement alone cannot reduce data uncertainty. It is also true that the inherent variability of natural materials cannot be truly captured unless sufficient field data is collected in an objective manner. \u0000This paper investigates the readiness of the technical community to integrate ML in rock engineering design at this time. To fully realise the potential and benefits of ML tools, the technical community must be willing to accept a paradigm shift in the data collection process and, if required, abandon empirical systems that are considered ‘industry standards’ by virtue of being commonly accepted despite acknowledging their limitations.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"382 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126672797","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":"A new stope reconciliation approach","authors":"B. McFadyen, K. Woodward, Y. Potvin, M. Grenon","doi":"10.36487/acg_repo/2035_17","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_17","url":null,"abstract":"Open stope mining remains the most widely used method for the underground extraction of hard rock metalliferous deposits since mines became increasingly mechanised from the early 1980s. One of the most significant factors that influence the value creation and profitability of open stope mining is linked to the ability of the mining process to accurately extract a designed stope. The performance of a stope is quantified during a reconciliation of the achieved excavation with respect to a planned geometry. Deviations from a planned stope volume can be categorised as material unintentionally mined (overbreak) or material intended to be mined but not recovered (underbreak). Conceptually, minimisation of both cases is important to mine economics as overbreak represents extra costs of mining waste while underbreak represents lost value from the sterilisation of ore. \u0000This paper describes a new approach for stope reconciliation that facilitates the identification of the root causes of overbreak and underbreak at three progressively finer levels of detail. This is achieved by quantifying stope performance with respect to the entire stope, individual stope faces and octree blocks. \u0000The reconciliation of an entire stope volume is systematically performed at most open stope mines and is often complimented by the reconciliation by individual stope faces. The octree analysis is a novel stope reconciliation technique that subdivides stope volumes into small blocks (usually <1 m). The sparse grid structure of this analysis enables the investigation to understand the relationship between stope performance and multiple factors such as blasthole standoff distance, orientation and blasting energy, effective radius factor, distance to development, distance and orientation to faults, and distance to convex hull. Stope reconciliation on a per octree basis assesses the stope at a resolution where the variation of performance and influencing factors can be captured and investigated.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122265050","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":"Solving rock mechanics issues through modelling: then, now, and in the future?","authors":"J. Sjöberg","doi":"10.36487/acg_repo/2035_0.02","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_0.02","url":null,"abstract":"There is no dispute about the advances in numerical modelling for rock mechanics applications following its debut in engineering science some 50 years ago. Significant strides have been made since the days of punch cards and line printers, with modelling tools now being easy to use and capable of replicating many, but not all, aspects of rock behaviour. This paper explores some common rock mechanics problems in underground mining, and how these have been addressed through numerical modelling. The described issues include pillar design, ground support, caving prediction and ground subsidence, and mining-induced seismicity. Examples of how modelling technology has evolved over the years are given, while also pointing out current gaps and limitations in the technology. Finally, an outlook for the future is presented, including some of the challenges we are facing. An increased fundamental understanding of many rock mechanics issues is still required, but eventually one may envision a deep integration of rock mechanical modelling into mine planning and production, for a more sustainable future mining.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122825473","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":"Rock forecast tool: new tool for rock mass quality prediction in tunnelling","authors":"A. Tapia, A. Farias","doi":"10.36487/acg_repo/2035_02","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_02","url":null,"abstract":"The tool presented in this article, known as rock forecast tool (RFT), is based on the quantitative interpretation of the geological characteristics obtained from the drilling of exploratory drill holes towards the unexcavated zone of tunnels under construction. This correlates the drilling results with rock quality values that have been previously calculated on the advanced faces. The results provided by this new tool are numerical values of rock mass quality in each of the drill rods used in exploratory drilling. \u0000The results obtained by the RFT have been subjected to different statistical tests such as the Pearson's correlation coefficient, R hypothesis test, confidence intervals and covariance test. All the tests carried out show that the RFT, used as a predictor, has a high correlation with the rock mass quality values that are subsequently calculated in the excavated sections, with an R2 = 0.95.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114201489","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":"Ground support and strata monitoring: what is needed?","authors":"O. Vallati, W. Roach, S. Weaver","doi":"10.36487/acg_repo/2035_13","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_13","url":null,"abstract":"With the ever-moving challenge to increase safety and productivity in mines, the ability to understand what your strata is doing in ‘real-time’ is incredibly important. New technologies need to be developed to allow time efficient monitoring of strata behaviour over the excavations desired life, along with the condition of ground support systems and how effectively they are functioning. \u0000Monitoring systems play an important function in maintaining the safe operation of underground mines. This paper will review technologies currently available; those being utilised and the effectiveness of such systems. \u0000Key desired outputs will be investigated along with the constraints of available technologies. To assist the underground mining industry to continue evolving in this area, an overview of digital trends will be provided as a guide to the direction for current and future technology developments.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"52 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131830892","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":"Benchmarking of stope design and reconciliation practices","authors":"Y. Potvin, K. Woodward, B. McFadyen, I. Thin, D. Grant","doi":"10.36487/acg_repo/2035_14","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_14","url":null,"abstract":"In 2019, the Australian Centre for Geomechanics organised a benchmarking workshop in Perth, Australia, followed by a second workshop in Rouyn-Noranda, Canada, under the sponsorship of BHP Olympic Dam. The workshops aimed to document the current stope design and reconciliation practices in open stoping operations from Australia and Canada. A total of 19 underground mines—including copper, gold, and base metal mines—provided data to the benchmarking study. The benchmarking study has provided data to further our understanding of the stope design and reconciliation process. \u0000The process can be simplified into four main steps: \u0000The main input and output for each of the steps, which are common to all mines, will be summarised in the paper. Standard and advanced practices within each step of the process will be described. Our interpretation of what are the main gaps in the design and reconciliation process will be discussed.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130374381","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":"Efficient paste mix designs using new generation backfill admixtures: perception versus reality","authors":"F. Erismann, M. Hansson","doi":"10.36487/acg_repo/2035_07","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_07","url":null,"abstract":"Backfilling mined out stopes with cemented paste has become the standard in most modern, long-hole stoping and cut-and-fill operations globally. The implementation of large-scale paste production plants and efficient underground paste reticulation systems contributed significantly to maximised ore extraction, higher levels of mine-scale geotechnical stability, larger degree of automation and last, but not least, to a more conscious management of mine processing waste. However, paste backfilling comes at a cost. \u0000Binder costs alone amount to 70–80% of total operating costs of paste plants depending on the strength requirements and characteristics of tailings used for backfilling and it is not uncommon that underground paste filling contributes up to 20% of the overall cost structure of an underground operation. With a view towards improving the paste mix designs and keeping cement consumption under control, new generation paste backfill admixtures have been developed over the past years. The mine backfill industry can be compared to the concrete industry 40 years ago, when high performance admixtures started to emerge for landmark projects, where exceptionally high concrete qualities and specific, fresh concrete properties were required (Aitcin & Wilson 2015). These high range water reducers quickly transformed the construction industry and pushed concrete applications to new, previously unknown limits. \u0000This paper intends to give an overview of the reality of admixtures in the mine backfill industry and their performance and justification in modern paste backfill plants with pump driven reticulation systems. Data from different paste plants around the globe has been compiled for this study, covering different deposit types, strength requirements and pumped paste mix designs. The study illustrates the powerful effect paste backfill admixtures can have on standard paste mix designs and their potential to reduce binder consumption substantially by remaining within the required strength and workability limits of the paste to improve the overall cost structure of backfill operations.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130774919","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":"Ground support loading monitored with Rock Bolt Sensor (RBS™) and relationship to nearby production and seismicity","authors":"L. Smith-Boughner, Zara Anderson, Zhigang Sun, D. Lévesque, S. Kruger, Y. Quenneville, A. Jalbout, Jonathan Szirti, R. Royer, R. Lacroix","doi":"10.36487/acg_repo/2035_12","DOIUrl":"https://doi.org/10.36487/acg_repo/2035_12","url":null,"abstract":"The National Research Council of Canada has developed a novel ultrasound based Rock Bolt Sensor (RBS™) to monitor load, deformation, and integrity of rock bolts. Several RBSs were deployed to monitor bolts in the roof of an intersection of two drifts and with another region of monitoring tens of metres away in the roof of the drift. The intersection spanned two rock types with different stiffness characteristics. The region was also covered by an extensive seismic system with a mixture of triaxial geophones and both triaxial and uniaxial accelerometers. \u0000Using three weeks of recorded data, the loading on 12 bolts was monitored during the production of several nearby stopes and analysed alongside the recorded seismicity. A significant increase in loading on the bolts in the roof was recorded when production occurred within 40 m of the instrumented intersection despite several other stopes producing more significant seismicity following blasting. The load was also taken up asymmetrically, with more substantial changes in load occurring in the bolts in the greywacke. \u0000During the study period, several large seismic events occurred within 500 m of the study area. Seismic moment tensor analysis was conducted on several of the seismic events to estimate the mechanism of failure and, using seismic stress inversion, the orientation of the observed fractures was estimated and the directions of principal stress. \u0000There was a strong increase in the load on the bolts located in the intersection, across the two different formations, several hours after a large seismic event occurred on that contact several hundred metres away. This work showed a connection between loading on the bolt and large changes in the local stress field due to nearby production and significant seismicity along structures in the region. In addition to monitoring the loading of the rock bolts, the Rock Bolt Sensor can be utilised to better understand the coseismic and postseismic deformation within the mine and improve models of the local stress field.","PeriodicalId":241197,"journal":{"name":"Proceedings of the Second International Conference on Underground Mining Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130879836","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}