Normalized Radiated Seismic Energy From Laboratory Fracture Experiments on Opalinus Clayshale and Barre Granite

We evaluate the radiated seismic energy normalized by external work for hydraulic fracturing, beam bending, and uniaxial compression experiments conducted on Opalinus clayshale and Barre granite specimens. Results suggest that normalized radiated seismic energy is highest for the beam bending, followed by uniaxial compression, and, finally, that the hydraulic fracturing experiments radiate the least seismic energy when normalized by external work. We also find that the normalized radiated energy during tests on Opalinus clayshale is 3% to 22% of that in Barre granite across multiple loading mechanisms

Normalized Radiated Seismic Energy From Laboratory Fracture Experiments on Opalinus Clayshale and Barre Granite

We evaluate the radiated seismic energy normalized by external work for hydraulic fracturing, beam bending, and uniaxial compression experiments conducted on Opalinus clayshale and Barre granite specimens. Results suggest that normalized radiated seismic energy is highest for the beam bending, followed by uniaxial compression, and, finally, that the hydraulic fracturing experiments radiate the least seismic energy when normalized by external work. We also find that the normalized radiated energy during tests on Opalinus clayshale is 3% to 22% of that in Barre granite across multiple loading mechanisms

Publishing Ethics

As all of our readers and authors know, there have been increasing problems with non-ethical behavior when publishing research. These problems range from not mentioning corresponding work by others, to publishing results that have not been sufficiently researched, to different degrees of plagiarism and fraud. So far, it appears that our journal has been spared the most serious infractions. However, there are subtle unethical aspects that have occurred with increasing frequency. Most notable is the publication of overlapping information in different journals; another issue is the resubmittal of articles that have been rejected by another journal. Both, the publication of overlapping material and resubmittal, are often justified. What is absolutely essential, however, is to inform the editors and thus the reviewers. This means that the overlapping material needs to be clearly identified or the rejection by another journal mentioned. This is not only the ethical standard that we, the editors, expect of our authors, but it is also in the authors’ interest to be associated with publications that follow these standards

Manuscripts Using Numerical Discrete Element Methods

The creation of numerical discrete element methods was a breakthrough in modeling discontinuous media and thus in modeling of rock masses. Recent developments in this domain, as also shown in a Special Issue of our Journal (Volume 45, Issue 5, September 2012), make it possible to simulate rock on any scale from intact rock composed of several particles to rock masse

Effects of tunneling on groundwater flow and swelling of clay-sulfate rocks

[1] Swelling of clay-sulfate rocks is a major threat in tunneling. It is triggered by the transformation of the sulfate mineral anhydrite into gypsum as a result of water inflow in anhydrite-containing layers after tunnel excavation. The present study investigates the hydraulic effects of tunneling on groundwater flow and analyzes how hydraulic changes caused by excavation lead to water inflow into anhydrite-containing layers in the tunnel area. Numerical groundwater models are used to conduct scenario simulations that allow one to relate hydrogeological conditions to rock swelling. The influence of the topographic setting, the excavation-damaged zone around the tunnel, the sealing effect of the tunnel liner, and the geological configuration are analyzed separately. The analysis is performed for synthetic situations and is complemented by a case study from a tunnel in Switzerland. The results illustrate the importance of geological and hydraulic information when assessing the risk of swelling at an actual site

Decision Support System for an Intelligent Operator of Utility Tunnel Boring Machines

In tunnel construction projects, delays induce high costs. Thus, tunnel boring machines (TBM) operators aim for fast advance rates, without safety compromise, a difficult mission in uncertain ground environments. Finding the optimal control parameters based on the TBM sensors' measurements remains an open research question with large practical relevance. In this paper, we propose an intelligent decision support system developed in three steps. First past projects performances are evaluated with an optimality score, taking into account the advance rate and the working pressure safety. Then, a deep learning model learns the mapping between the TBM measurements and this optimality score. Last, in real application, the model provides incremental recommendations to improve the optimality, taking into account the current setting and measurements of the TBM. The proposed approach is evaluated on real micro-tunnelling project and demonstrates great promises for future projects.Comment: 17 pages, 5 figures, 3 table

Rock Slopes from Mechanics to Decision Making

http://lmrwww.epfl.ch/Eurock/Eurock2010/files/papers%20grouped.pdfRock slope instabilities are discussed in the context of decision making for risk assessment and management. Hence, the state of the slope and possible failure mechanism need to be defined first. This is done with geometrical and mechanical models for which recent developments are presented. This leads with appropriate consideration of uncertainties to risk determination and to the description of tools for risk management through active and passive countermeasures, including warning systems. The need for sensitivity analysis is then demonstrated, and final comments address updating through information collection.National Science Foundation (U.S.)MIT-Portugal ProgramPortuguese Science and Technology FoundationNorwegian Geotechnical Institute (International Centre for Geohazards)United States. Dept. of Energ

Fluctuations of an Atomic Ledge Bordering a Crystalline Facet

When a high symmetry facet joins the rounded part of a crystal, the step line density vanishes as sqrt(r) with r denoting the distance from the facet edge. This means that the ledge bordering the facet has a lot of space to meander as caused by thermal activation. We investigate the statistical properties of the border ledge fluctuations. In the scaling regime they turn out to be non-Gaussian and related to the edge statistics of GUE multi-matrix models.Comment: Version with major revisions -- RevTeX, 4 pages, 2 figure

Fractured reservoir discrete feature network technologies. Annual report, March 7, 1996--February 28, 1997

This report describes progress on the project, {open_quotes}Fractured Reservoir Discrete Feature Network Technologies{close_quotes} during the period March 7, 1996 to February 28, 1997. The report presents summaries of technology development for the following research areas: (1) development of hierarchical fracture models, (2) fractured reservoir compartmentalization and tributary volume, (3) fractured reservoir data analysis, and (4) integration of fractured reservoir data and production technologies. In addition, the report provides information on project status, publications submitted, data collection activities, and technology transfer through the world wide web (WWW). Research on hierarchical fracture models included geological, mathematical, and computer code development. The project built a foundation of quantitative, geological and geometrical information about the regional geology of the Permian Basin, including detailed information on the lithology, stratigraphy, and fracturing of Permian rocks in the project study area (Tracts 17 and 49 in the Yates field). Based on the accumulated knowledge of regional and local geology, project team members started the interpretation of fracture genesis mechanisms and the conceptual modeling of the fracture system in the study area. Research on fractured reservoir compartmentalization included basic research, technology development, and application of compartmentalized reservoir analyses for the project study site. Procedures were developed to analyze compartmentalization, tributary drainage volume, and reservoir matrix block size. These algorithms were implemented as a Windows 95 compartmentalization code, FraCluster

On the Possibility of Measuring the Gravitomagnetic Clock Effect in an Earth Space-Based Experiment

In this paper the effect of the post-Newtonian gravitomagnetic force on the mean longitudes $l$ of a pair of counter-rotating Earth artificial satellites following almost identical circular equatorial orbits is investigated. The possibility of measuring it is examined. The observable is the difference of the times required to $l$ in passing from 0 to 2$\pi$ for both senses of motion. Such gravitomagnetic time shift, which is independent of the orbital parameters of the satellites, amounts to 5$\times 10^{-7}$ s for Earth; it is cumulative and should be measured after a sufficiently high number of revolutions. The major limiting factors are the unavoidable imperfect cancellation of the Keplerian periods, which yields a constraint of 10$^{-2}$ cm in knowing the difference between the semimajor axes $a$ of the satellites, and the difference $I$ of the inclinations $i$ of the orbital planes which, for $i\sim 0.01^\circ$, should be less than $0.006^\circ$. A pair of spacecrafts endowed with a sophisticated intersatellite tracking apparatus and drag-free control down to 10$^{-9}$ cm s$^{-2}$ Hz$^{-{1/2}}$ level might allow to meet the stringent requirements posed by such a mission.Comment: LaTex2e, 22 pages, no tables, 1 figure, 38 references. Final version accepted for publication in Classical and Quantum Gravit