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Doctor of Philosophy
Get PDFdissertationQuestar Corporation commissioned and funded this research, in partnership with the University of Utah and Bechtel Corporation, to develop methods of protecting steel natural gas pipelines crossing zones of permanent ground deformation. The goal of this research was the development and testing of an Expanded Polystyrene (EPS) Geofoam cover system for such pipelines across active faults or areas of permanent ground deformation (e.g., landslides, permafrost thaw, liquefaction-induced lateral spread). The goal of an EPS Geofoam cover system atop a buried pipeline is to reduce the lateral, longitudinal and vertical forces induced on the pipe as the surrounding ground undergoes permanent deformation. The properties of EPS Geofoam have distinct advantages that lead to improved pipe performance during large ground deformation. The most important of these are its low unit weight and relatively high compressibility. These advantages are the primary focus of this research. Further, the interaction of a pipe and EPS Geofoam was explored and analyzed in a loading case where the pipe was pushed directly into the EPS. In addition to laboratory-scale tests, full-scale tests were conducted with vertical and horizontal plane strain movement of pipe interacting with EPS Geofoam cover systems. Subsequently, numerical modeling was done of the field tests to further evaluate the use of an EPS cover system for applications experiencing large, permanent deformation. The results of the research program have shown that EPS Geofoam can be used as a cover system for steel pipelines crossings at active normal faults, or for other types of permanent ground deformation where the expected offset is predominately vertical
Protection of Pipelines and Buried Structures Using EPS Geofoam
No full textExpanded Polystyrene (EPS) geofoam is a lightweight, compressible material that can be used to protect buried infrastructure in areas with high to moderate seismicity. This paper summarizes recent research conducted at the University of Utah regarding the seismic design and construction of EPS geosystems to improve the seismic resiliency of pipelines and buried structures, particularly at normal fault crossings. It discusses the development and verification of an EPS cover/backfill system to protect buried pipelines and other structures from potential rupture caused by permanent ground deformation (e.g., tectonic faulting, subsidence, liquefaction, land sliding, etc. Full-scale experiments and numerical modeling show that a light-weight cover system constructed, in part, with EPS block offers significant benefits in protecting buried pipelines from the damaging effects of offset caused by permanent ground deformation. The prototype EPS cover system significantly reduced the vertical uplift force and stresses imposed on the buried pipe system as it was subjected to uplift through the EPS cover system
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
A Phased Reconnaissance Approach to Documenting Landslides Following the 2016 Central Italy Earthquakes.
Get PDFThe 2016 Central Italy earthquake sequence caused numerous landslides over a large area in the Central Apennines. As a result, the Geotechnical Extreme Events Reconnaissance Association (GEER) organized post-earthquake reconnaissance missions to collect perishable data. Given the challenging conditions following the earthquakes, the GEER team implemented a phased reconnaissance approach. This paper illustrates this approach and how it was used to document the largest and most impactful seismically induced landslides. This phased approach relied upon satellite-based interferometric damage proxy maps, preliminary published reports of observed landslides, digital imaging from small unmanned aerial vehicles (UAVs), traditional manual observations, and terrestrial laser scanning. Data collected from the reconnoitered sites were used to develop orthophotos and meshed three-dimensional digital surface models. These products can provide valuable information such as accurate measurements of landslide ground movements in complex topographic geometries or boulder runout distances from rock falls. The paper describes three significant landslide case histories developed and documented with the phased approach: Nera Valley, Village of Pescara del Tronto, and near the villages of Crognaleto and Cervaro
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Settlement of Large Embankment Construction Adjacent to a Buried Gas Pipeline — A Case History in Settlement Mitigation Using Lightweight Fill
Get PDFAs part of the $1.7 Billion I-15 CORE highway reconstruction project in Utah, several new or enlarged large embankments were constructed adjacent to existing buried utilities. Lightweight fill was selected as the technology to limit distress to the adjacent utilities. In order to estimate the impact from new construction to the utilities, settlement estimates for the lightweight embankment were performed using traditional settlement estimating techniques. Numerical models using FLAC3D were then performed to refined estimates. Estimates of lightweight embankment foundation settlements from this construction were obtained from the finite difference modeling. Three-dimensional numerical modeling was used in order to evaluate the foundation settlements since numerical modeling can better estimate the induced stresses and deformations of subsurface soils for complicated geometry, loading history, and for locations outside of the loaded area. During and after construction of the embankments, foundation soil settlement was measured for the lightweight embankments. Settlement estimates from traditional engineering methods and the FLAC3D analyses were compared to the observed settlement data. Sensitive buried utilities were successfully protected by use of lightweight fills, and engineering settlement estimates were shown to agree well with measured settlement data. This case history shows how urban highway re-construction on soft soils, which will likely become more common in the future, can be designed and constructed to reliably protect existing structures
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