1. |
- Barbens, P.T., et al.
(author)
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Improving teaching methods of rock mass classification parameters
- 2014
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In: Rock Engineering and Rock Mechanics. - : CRC Press. - 9781138001497 - 9781315749525 ; , s. 451-455
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Conference paper (peer-reviewed)abstract
- To promote knowledge in rock mass classification methods, a short course was arranged in research tunnels beneath Aalto University in Espoo, Finland. After the course, the participants had a short (45+45 min) hands-on tunnel mapping exercise where they logged 12 core boxes and one 10 m tunnel wall section. The attendees were asked to submit their mapping sheets for a post-study. The objective of the study was to discover which parameters show most scatter and to develop suggestions to improve the teaching methods. Statistical analysis of the data was carried out and RQD parameter was analyzed in more detail as it had the largest amount of data. Insufficient logging time may be one of the causes for the lack of data for other parameters. Significant scatter was observed in the RQD parameter and the comparison between inexperienced and experienced mappers show no clear difference. The teaching arrangements and problems faced are stated and recommendations on how to improve the situation are presented.
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2. |
- Bhadani, Kanishk, 1991, et al.
(author)
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CDIO Course Development for Faculty in Raw Materials Programmes
- 2017
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In: The 13th International CDIO Conference Proceedings, Calgary, Canada. - 1796-9964. - 9780889533998 ; , s. 315-326
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Conference paper (peer-reviewed)abstract
- In Europe, the existing MSc programmes which are linked to the thematic Raw Material content often focus mainly on technical knowledge in itself, and students graduate as professionals who know how to solve pre-defined technical problems. Students in such programmes seldom practice entrepreneurial, communication and innovation skills at a level that is needed in working life. On the other hand, the CDIO Initiative has developed a framework for modernizing engineering education by introducing such skills and thinking into the technical programmes and courses. It is widely discussed in the CDIO community that one of the constraints in implementing CDIO is faculty staff professional development. CDIO standards 9 and 10 focus on the faculty development and competencies both in terms of pedagogic as well as learning methods to deal with personal and interpersonal skills, and product, process, and system building skills. In order to bring a change and implement CDIO into the Raw Materials programmes in Europe, a modular course for training in CDIO was developed and delivered for the faculty member in the Raw Materials sector. This paper accounts for the development of the faculty training course, and provides a unique perspective on the implementation of CDIO into raw materials related programmes capturing the different models of implementation from different universities’ programmes and courses. The various universities involved provide programmes and courses across the entire value chain of raw materials from mining and minerals processing to materials design, sustainability and recycling. This paper will serve as a reference for the educators to develop and implement CDIO education methods in specific disciplines as illustrated here in the field of raw materials related programmes.
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3. |
- Edelbro, Catrin, et al.
(author)
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A quantitative comparison of strength criteria for hard rock masses
- 2007
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In: Tunnelling and Underground Space Technology. - : Elsevier BV. - 0886-7798 .- 1878-4364. ; 22:1, s. 57-68
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Journal article (peer-reviewed)abstract
- Knowledge of the rock mass strength is important for the design of all types of underground excavations. A frequently applied approach for estimation of the rock mass strength is through an empirical failure criterion, often in conjunction with rock mass classification/characterisation systems. This paper presents a review of existing methods to estimate the rock mass strength using empirical failure criteria and classification/characterisation systems—in this study, commonly denoted as estimation methods. A literature review of existing methods is presented, after which a set of methods were selected for further studies. The selected methods were used in three case studies, to investigate their robustness and quantitatively compare the advantages and disadvantages of each method. A Round Robin test was used in two of the cases. The case studies revealed that the N, Yudhbir-RMR76, RMi, Q-, and Hoek–Brown-GSI methods, appeared to yield a reasonable agreement with the measured strengths. These methods are thus considered the best candidates for realistic strength estimation, provided that care is taken when choosing values for each of the included parameters in each method. This study has also clearly shown the limits of presently available strength estimation methods for rock masses and further work is required to develop more precise, practical, and easy-to-use methods for determining the rock mass strength. This should be based on the mechanical behaviour and characteristics of the rock mass, which implies that parameters that consider the strength of intact rock, block size and shape, joint strength, and physical scale, are required.
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4. |
- Edelbro, Catrin
(author)
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Bestämning av bergmassans hållfasthet med hjälp av bergkaraktärisering
- 2004
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In: Bergmekanikdag 2004 Föredrag. - : SweBeFo. ; , s. 41-51
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Conference paper (other academic/artistic)abstract
- Knowledge of the rock mass behaviour in general, and the failure process and the strength in particular, is important for the design of all kinds of underground excavations. Existing classification/characterisation systems and rock mass failure criteria have been studied due to their applicability to hard rock masses. The most important parameters that are needed to determine the rock mass strength is identified and described. The existing rock mass failure criteria have been studied in a critical case, divided into two parts. The first part consists of a "Round Robin Test", in which a number of participants, working with rock mechanics, have determined the rock mass strength for some chosen systems and criteria, based on the same input data. Two cases where studied - one pillar from the Laisvall mine and one fictitious tunnel case. The second part treats a strength determination based on a large-scale test from Stripa. The aim of the case studies is to study the robustness of each system and criteria and to identify which parameters that are important for the rock mass strength determination and sensitive due to variations and/or have a definition that gives a large interval of the result. Based on the case studies, the most applicable and robust failure criteria and characterisation system could be identified.
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5. |
- Edelbro, Catrin
(author)
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Different Approaches for Simulating Brittle Failure in Two Hard Rock Mass Cases: A Parametric Study
- 2010
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In: Rock Mechanics and Rock Engineering. - : Springer Science and Business Media LLC. - 0723-2632 .- 1434-453X. ; 43:2, s. 151-165
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Journal article (peer-reviewed)abstract
- One of the aims of rock mechanics analysis is to predict fallouts in underground excavations. The objective of this paper was to study the relative importance of different strength parameters and their significance on the simulation of brittle failure and fallouts. This work was conducted as a parametric study, using numerical modelling and a number of approaches. The results were compared with observed fallouts. More obvious and distinct shear bands could be observed with decreased element sizes close to, and at, the boundary. The maximum shear strain was the most reliable indicator for fallout prediction. The results of the (instantaneous) cohesion softening friction softening models were sensitive to changes of the peak strength parameters and less sensitive to variations in residual parameters. The result from the cohesion-softening friction-hardening (CSFH) model, when using a peak cohesion equal to the intact rock strength, best captured the observed rock behaviour.
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6. |
- Edelbro, Catrin, et al.
(author)
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Engaging with Program Stakeholders to Support Program Development
- 2017
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In: The 13th International CDIO Conference Proceedings - Full Papers. - Calgary.
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Conference paper (peer-reviewed)abstract
- Luleå University of Technology (LTU) has adopted CDIO as the framework for developing its engineering programs. At the Department of Civil, Environmental and Natural Resources Engineering, there are two programs focusing on tunnelling, mining and rock excavation. Despite very positive prospects for professionals in the field, the number of students has decreased for the last two years. Further, program content might not reflect recent developments or new requirements in the industry. Therefore, the programs and their courses are taken under renewed consideration. Given the nature of the challenges facing the programs, it is in this case particularly important to inform of the planned development through a dialogue with stakeholders. Stakeholder dialogue is also a key feature of a CDIO curriculum development (CDIO Standard 2). This paper reports on a process of engagement with industry representatives, initiated through a meeting to discuss the competence of newly graduated from LTU as well as the future needs in the industry. The input will make it more visible what programme and course development work needs to be done in the nearest future. A continued support and feedback from the industry is warranted during the programme development.
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7. |
- Edelbro, Catrin, et al.
(author)
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European initiative on CDIO in raw material programmes
- 2017
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In: Proceedings of the 13th International CDIO Conference in Calgary. - Calgary.
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Conference paper (peer-reviewed)abstract
- One of five Knowledge and Innovation Communities (KICs), was launched in Europe in 2014and has its focus on exploration, extraction, mineral processing, metallurgy, recycling andmaterial substitution of raw materials. To reach the vision, where the European Union’sindustrial strength is based on a cost-efficient, secure, sustainable supply and use of rawmaterials, a new generation of skilled people entering industry, universities and researchneeds to be developed. Today’s technical MSc graduates in raw materials and especiallyprimary resources (i.e. exploration, extraction, mining and mineral processing and metallurgy)best suits large companies where they often act as specialists and experts. For small tomedium enterprises as well as for our future engineers other skills than technical arenecessary. As a part of the KIC Raw Materials, the education project “The implementation ofCDIO in raw material programmes” started in 2016. The project focuses, during 2016-2017,on (WP1) faculty- and (WP2) pilot case development. There are no academic institutes inEurope that have yet applied CDIO for primary resource related MSc programmes. Thispaper describes an education project within the KIC Raw material and presents key outputswith implementing CDIO in mining and metallurgy related programmes.
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8. |
- Edelbro, Catrin
(author)
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Evaluation of rock mass strength criteria
- 2004
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Licentiate thesis (other academic/artistic)abstract
- Knowledge of the rock mass behaviour in general, the failure process and the strength in particular, is important for the design of all kinds of underground excavations. One of the most common ways of estimating the rock mass strength is by using a failure criterion. The existing rock mass failure criteria are stress dependent and often include one or several parameters that describe the rock mass properties. These parameters are often based on classification or characterisation systems. A comprehensive literature review of existing classification/characterisation systems and rock mass failure criteria has been performed. As the application of this licentiate thesis is for hard rock masses some limitations have been stated on the systems and criteria. The limitations of the classification/ characterisation systems are that they should present a result that is relevant for the strength, give a numerical value, have been used after the first publication and be applicable to hard rock masses. Based on the literature review, it was concluded that the uniaxial compressive strength, block size and shape, joint strength and a scale factor are the most important parameters that should be used when estimating the rock mass strength. Existing rock mass failure criteria and classification/characterisation systems have been evaluated through the use of case studies. The aim of the case studies was to identify robust systems and criteria, parameters having the strongest impact on the calculated rock mass strength and those giving a large interval of the result. The case study revealed that the rock mass quality (Q-system), rock mass Number (N-system), Rock Mass index (RMi) system, Yudhbir – Rock Mass Rating (RMR76) and Hoek-Brown – Geological Strength Index (GSI) seem to be the most suitable systems and criteria to use when determining the rock mass strength. None of the systems or criteria complies with the requirements of a method to determine the rock mass strength and a better rock mass strength estimation method should be developed. This requires more case histories where the determined/estimated rock mass strength from the criteria/systems can be compared to the measured/determines rock mass strength.
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9. |
- Edelbro, Catrin, et al.
(author)
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Implementering av 2:a generationens Eurokod inom bergbyggande
- 2022
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In: Bergdagarna 2022. - Stockholm.
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Conference paper (pop. science, debate, etc.)abstract
- I november 2020 publicerades de första kompletta utkasten till 2:a generationen av Eurokod inom geoteknikområdet (EN 1997-1, EN 1997-2 samt EN 1997-3). Dessa reviderade Europastandarder förväntas vara implementerade i branschen år 2026. Denna artikel belyser delar av det pågående arbetet inom Implementeringskommissionen för Europastandarder inom Geotekniken (IEG 2.0). Indelning i delområden som IEG 2.0 valt att fokusera på och etablering av arbetsformer för dessa områden presenteras. Inom varje delområden genomförs olika typer av projekt med syfte att bidra till en fungerande och kommunicerad standard i branschen. Konkreta exempel på projekt som pågår och som fångar upp de förändringar som blir med den nya generationen beskrivs. Vidare presenteras projekt som berör nya definitioner och beskrivningar som bedömts ha en stor nationell påverkan på bergbranschen. Under år 2021 utfördes i huvudsak projekt som berör grundläggande frågeställningar. Projekt som berör tillämpning och samordning startade under början av år 2022.
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