Geotechnical Engineering for Mass Mining

SEG Discovery ◽  
2020 ◽  
pp. 22-31
Author(s):  
Andre van As

Editor’s note: The Geology and Mining series, edited by Dan Wood and Jeffrey Hedenquist, is designed to introduce early-career professionals and students to a variety of topics in mineral exploration, development, and mining, in order to provide insight into the many ways in which geoscientists contribute to the mineral industry. Abstract The rock mass response to mining is governed by the rock mass characteristics and the mining-induced changes that drive its behavior. To be able to study and accurately predict the response of the rock mass to mining, it is imperative that both the orebody and the enclosing country rocks are well characterized through the collection and analysis of large quantities of good-quality, representative geologic, structural, geotechnical, and hydrogeological data. These are the fundamental constituents of a good geotechnical model whose reliability improves as the mining project matures and moves from exploration and study phases, passes the decision to develop, and proceeds into construction and then operations. Each phase provides greater exposure to the rock mass, reduces uncertainty, and increases reliability in the geotechnical model and in an understanding of the rock mass behavior. The quest of the geotechnical engineer is to understand the rock mass behavior and is no different from that of the geologist who defines the mineral resource, and it warrants (at the very least) the same level of rigor in data collection, analysis, and reporting. Just as the geologist continues to improve the orebody model through grade reconciliation during mining, so the geotechnical engineer must continually revisit and calibrate the geotechnical model during the operational phase of mining through geotechnical monitoring. The increasing demand by investors and stakeholders that the performance of a mine does not deviate from plan due to unforeseen geotechnical surprises warrants a significant shift in the level of geotechnical data collection, analyses, and rock mass monitoring through all stages of study and operations. This demand warrants supporting budgets and assurance processes that are commensurate with the complexity and extent of the geotechnical uncertainties.

SEG Discovery ◽  
2020 ◽  
pp. 16-28
Author(s):  
Sarah Mackenzie ◽  
Jo-Anne Everingham ◽  
Pam Bourke

Editor’s note: The Geology and Mining series, edited by Dan Wood and Jeffrey Hedenquist, is designed to introduce early-career professionals and students to a variety of topics in mineral exploration, development, and mining, in order to provide insight into the many ways in which geoscientists contribute to the mineral industry. Abstract Geoscientists are often the first point of contact a local community has with a company conducting mineral exploration. The behavior of the geoscientists and the interest they take in understanding the local community and stakeholders will have ramifications well beyond their direct exploration activities. This article highlights some of the positive and negative impacts exploration can have for local communities (in part drawing on interviews with experienced geoscientists and others involved in exploration). The article explores the increasing complexity of deposits in terms of environmental, economic, social, and political parameters and the increasing scrutiny by local stakeholders and the international community. We argue that, although geoscientists are not social performance specialists, they still need the awareness, tools, and capabilities to understand and manage the social aspects of their exploration activities commensurate with the stage and resourcing of the project. We propose three interrelated aspects of social performance that can be applied during mineral exploration: meaningful and positive engagement, acquiring and documenting a social knowledge base, and strategic investment in the community. Two case studies provide cautionary examples of failure to do so and two case studies highlight how, through careful engagement and strategic collaboration, mutually beneficial and positive relationships can be built from early exploration.


SEG Discovery ◽  
2020 ◽  
pp. 23-34 ◽  
Author(s):  
John Orpen ◽  
David Orpen

Editor’s note: The Geology and Mining series, edited by Dan Wood and Jeffrey Hedenquist, is designed to introduce early-career professionals and students to a variety of topics in mineral exploration, development, and mining, in order to provide insight into the many ways in which geoscientists contribute to the mineral industry. Abstract The diamond drill is the most productive tool available for the earth scientist to explore and map the subsurface. However, the quality of the information obtained for analysis and modeling depends on how well the processes involved are understood so as to eliminate systematic and human error and effectively minimize the variables causing random error. This overview of the quality assurance and quality control (QA/QC) procedures required to manage these errors starts with the planning phase of a drilling program and goes through drill rig setup, borehole depth measurement, core recovery measurement, core depth registration, core orientation, borehole survey, and borehole path reconstruction. An outline follows of the methods used in the logging process to accurately depth reference the data recorded from both core and bore, as well as to ensure that the angles measured for structures are verified and correctly rotated to derive their in situ dip and dip direction or plunge and trend. To conclude, the provisions required for effective audits of the drilling and logging QA/QC processes are discussed: testing for inconsistencies, certifying that standards have been achieved, reporting on weaknesses, and making recommendations for improved performance.


SEG Discovery ◽  
2019 ◽  
pp. 1-22
Author(s):  
Dan Wood, AO ◽  
Jeffrey Hedenquist

Editor’s note: The Geology and Mining series, edited by Dan Wood and Jeffrey Hedenquist, is designed to introduce early-career professionals and students to a variety of topics in mineral exploration, development, and mining, in order to provide insight into the many ways in which geoscientists contribute to the mineral industry. Abstract For economic geologists, mineral exploration has a specific objective: the discovery of mineral concentrations that can be recovered economically to provide resources essential for society. This was achieved consistently until the first decade of the current century, but exploration since then has been wealth destructive. This outcome is a major issue for the mining industry unless reversed. We believe the technologies presently used to discover ore deposits will be as useful in making future discoveries as they were previously. However, we argue that a new approach is required in how exploration is conducted and in how these and emerging technologies are applied. The required changes in approach include improved business models for conducting exploration and acceptance that fewer deposits are likely to be discovered near the surface. We argue that discovery of deeper deposits will be facilitated if exploration teams (1) seek to identify subtle evidence of mineralized rock recognizable within 500 m of the surface, (2) conduct follow-up investigations with a clear understanding of the volumetric dimensions of the discovery target, and (3) drill boldly as a critical exploration tool. We propose that improving the way geoscientists think when exploring—being more predictive—is the immediate key to increasing the number of discoveries.


SEG Discovery ◽  
2021 ◽  
pp. 25-36
Author(s):  
Adrian Pratt

Editor’s note: The Geology and Mining series, edited by Dan Wood and Jeffrey Hedenquist, is designed to introduce early-career professionals and students to a variety of topics in mineral exploration, development, and mining, in order to provide insight into the many ways in which geoscientists contribute to the mineral industry. Abstract Mining narrow deposits presents a discrete set of additional challenges to those common to most mining. Some challenges arise from the deposit’s width, its geometry—dip and planar continuity—and its interaction with the surrounding rock mass. The geology of the surrounding rock mass and associated physical properties of its geologic units and structures influence the application of mining method and mine design for both surface (open-pit) and underground mining. Successful mine development is the product of teamwork and depends on the collaboration, coordination, collective experience, and confidence of the team. Above all, it relies on relationships shared by the team members along the value chain. These relationships are extremely important, since miscommunication, misunderstandings, missing data, etc., can result either in lost opportunities to develop a better mine, or will load the project with unnecessary risk. This article is focused on underground mining of narrow-width deposits (veins) and the role of economic geologists in the definition and development of these deposits. The crucial importance of recognizing potential for value creation early in the life of a narrow-width mine project is highlighted, when an economic geologist is often a project’s key proponent. This role as the key proponent may change as a project progresses toward development, but early geologic contributions provide the foundation for narrow-width mine development.


2019 ◽  
Vol 1 (02) ◽  
pp. 64-67
Author(s):  
Meilisha Putri Pertiwi ◽  
Suci Siti Lathifah

Research on the condition of the nesting habitat of Chelonia mydas (green turtle) in Pangumbahan Beach, Ujung Genteng, South Sukabumi has been carried out. Data retrieval is done 6 times for 2 days, 27-28 November 2017 at 3 observation stations. The abiotic parameters measured include surface temperature and depth of 50 cm, surface humidity and depth of 50 cm, beach width, beach slope, and the size of sand grains. While the biotic parameters measured were density, relative density, the frequency of attendance, and distribution patterns of Pandanus tectorius (sea pandanus) vegetation. Based on the results of data processing, the biophysical conditions in Pangumbahan Beach are still suitable for the Chelonia mydas nesting habitat. It also got clear evidence of the many Chelonia mydas landings during the data collection.


2019 ◽  
Vol 7 (2) ◽  
pp. 150-159
Author(s):  
Suharyanto H Soro

Lecturer plays an important role in teaching Englishas a foreign language, in spite of the success of teaching English itself depends on the many factors, one of them is students’ participation in the English class. In the other words, the teaching of English becomes useful and more systematically when the lecturer is fully aware of the aims and values of teaching of English subject since the core principle of any teaching  is “know what you do and only do what you know”. Hence it is essential to understand the aims and values of teaching English. In linguistics study,performance and competence are different, competence is study about language rules in the abstract form or one’s capacity to use a language, while performance is the application of one’s ability in the concrete form, or the actual application of this competence in speaking or listening. Chomsky (1965:18) said that  performance is the effect or the application of competence. Further he said that clearly, the actual data of linguistic performance will provide much evidence for determining the correctness of hypotheses about underlining linguistic structure. Notice the following figure. The data collection procedures in the present study are based on classroom participant observation, student interviews, and questionnaire  are the primary sources of data collection. As a point of departure, unstructured interviews conducted with English and students to gain initial understanding of the learning English as a foreign language. This also serves as a pilot study, paving the way for designing the guidelines for the semi structured individual interviews. Notes taken in these unstructured interviews were included in the data analysis. Taking lecture involves the lecturer and the students in formal setting. Lecturer is one who transfers special knowledge (English teaching materials) to his students in form of academic setting. They are engaged in academic norms, for example lecturer has qualified education (magister or doctorate degree) and the students  have already registered their status as a university student. The lecturer’s function is threefold. In the presentation stage of the material, the lecturer serves as a model, setting up situations in which the need for the target structure is created and modeling the new structure for students to repeat. The lecturer was required to be skillful manipulator, using questions, commands, and other cues to elicit correct sentences from the students. The students wanted the lecturer to give more opportunities for English practice. They can learn from mistakes and develop in real situation. Role play is one of methods can be applied in teaching English. The students like this methods (96%) because they can imitate and practice their English pronunciation.


Author(s):  
Mohammad Lutfur Rahman

Purpose Among the many studies about risk perception, only a few deal with Bangladesh. Paul and Bhuiyan’s (2010) study has shown the earthquake-preparedness level of residents of Dhaka, but there are some biases in the data collection. This paper aims to examine the seismic-risk perception and the level of knowledge on earthquake and preparedness among the residents of Dhaka. Design/methodology/approach A questionnaire was developed, and data collection was undertaken through home and sidewalk surveys. This paper investigates how attitude, perception and behavior differ depending on gender, age, education and casualty awareness. This research tries to examine and make a comparison of the risk perception and preparedness level between different groups of gender, age and level of education. Findings This research shows that female respondents have a much better risk perception of and are better prepared for earthquakes than male respondents; younger people have a higher knowledge about earthquake preparedness than older people and less-educated people are at a higher risk of unpreparedness than more-educated people. Research limitations/implications This research is only limited to the Dhaka Division. Originality/value This paper concludes by noting that public awareness on seismic-risk perception and mitigation is poor, and their knowledge on basic theory and emergency response must be improved.


2007 ◽  
Vol 44 (8) ◽  
pp. 1151-1168 ◽  
Author(s):  
Peter J Barnett

Many previously published studies of the behaviour of Pt and Pd in till and soils have been done in areas of complex stratigraphy or very thin overburden cover, making the interpretation of soil results difficult because of the many variables associated with these settings. At the Lac des Iles mine site in northwestern Ontario, there are excellent exposures of the overburden in a series of exploration trenches. Glacial dispersal trains can be observed in till (C horizon) geochemistry (e.g., Ni, Cr, Cu, and Co). Regional geochemical dispersal trains of elements, such as Ni, Cr, Mg, and Co associated with the North Lac des Iles intrusion, can be detected for about 4 km beyond the western margin of the Mine Block intrusion. Entire dispersal trains range from 5 to 7 km in length and about 1 to 2 km in width. The dispersal of North Lac des Iles intrusion rock fragments tends to mask the response of the Mine Block intrusion. Dispersal trains of Pt and Pd are not well defined and tend to be very short, <1 km in length, due to the initial low concentrations of these elements in C-horizon till samples from the Lac Des Iles area. An exception to this is the Pd dispersal train originating from the high-grade zone that is up to 3 km long. Pd, Pt, Ni, and Cu appear to be moving both within and out of the soil system downslope into surface and shallow groundwater. It is suggested that these elements, to varying degrees, are moving in solution. Airborne contamination from mine operations of the humus has adversely affected the ability to determine the effectiveness of humus sampling for mineral exploration at Lac des Iles. The airborne contamination likely influences the geochemical results from surface water, shallow groundwater, and near-surface organic bog samples, particularly for the elements Pd and Pt.


Author(s):  
Seth J. Schwartz

This book covers the process of writing for publication from start to finish—from selecting a topic and reviewing literature to working with coauthors, writing theoretical and review articles, and responding to editor and reviewer comments when revising manuscripts. Dr. Schwartz uses examples from his own scholarly publishing career and provides concrete advice for both early-career and more experienced writers. The book also covers important topics such as planning studies, managing and supervising data collection, retaining participants in longitudinal studies, data analytic ethics and conflicts of interest, and dealing with writer’s block. Dr. Schwartz provides guidance for writing journal articles, books, and book chapters, as well as for dealing with manuscripts that have been repeatedly rejected. He offers guidance for writing first drafts, editing drafts, incorporating coauthor feedback, and working with difficult or resistant coauthors. This book is a “how-to” in terms of writing for publication.


Author(s):  
M Perras ◽  
E Ghazvinian ◽  
M Diederichs ◽  
F Amann ◽  
H Wannenmacher

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