Gabriela Medero - Academia.edu (original) (raw)
Uploads
Papers by Gabriela Medero
Computers and Geotechnics, Oct 1, 2023
Vadose Zone Journal, 2019
Proceedings of the Third International Conference on Railway Technology: Research, Development and Maintenance, Mar 10, 2016
CRC Press eBooks, Sep 13, 2012
The running of high-speed trains on ballasted railway tracks requires excellent track geometry an... more The running of high-speed trains on ballasted railway tracks requires excellent track geometry and reliability. Three-dimensional polyurethane GeoComposites have been used at many sites across the United Kingdom (UK) to help solve traditional ballast maintenance issues that arise at critical track assets like switch and crossings and transition zones. This paper presents work done on the technique and shows the results of laboratory tests and real site application. In particular the paper concentrates on the application of the technology to transition zones. The issues surrounding transition zone dynamics are discussed and the problem is analyzed through the results of advanced 3-dimensional finite element modeling using the DART3D software. The simulations presented in this paper show how the transition fault develops and how the track stiffness is affected by different transition attributes, such as voiding and track stiffness changes. The use of polyurethane GeoComposite technology for high-speed transition zone reinforcement is then presented and the results of simulations shown as to its effectiveness.
Social Science Research Network, 2022
Soils and Foundations, Jun 1, 2023
Geomechanics for Energy and the Environment, Mar 1, 2023
CRC Press eBooks, Jun 19, 2009
In this paper the application of polymer geocomposite technology to the reduction/elimination of ... more In this paper the application of polymer geocomposite technology to the reduction/elimination of long standing railway track faults is presented. The polymers used are urethane cross linked polymers that are applied directly to the ballast matrix using on site mixing equipment. Application of the urethane cross linked polymers allows a high degree of visco-elasticity and hence polymer damping characteristics. The formed structure cures within seconds to form a resilient and very strong polymer/ballast geocomposite. The paper describes how the polymer improves the engineering properties of the in situ ballast and presents typical laboratory studies on engineering behavior. Finite element simulations of railway track response before and after polymer application are included to show how the polymer geocomposite behaves under actual train loading. A typical application of the technique to a highspeed, high axle load switch and crossing on the UK West Coast Main Line is described.
International Journal of Geomechanics, Apr 1, 2023
Engineering Geology, Jul 1, 2023
Geometrical Optics (GO) and Physical Optics (PO) have been popular methods to analyse reflector a... more Geometrical Optics (GO) and Physical Optics (PO) have been popular methods to analyse reflector antennas. Although both techniques have extensively been used in the literature and are shown to produce overall accurate results, they lead to some differences in the obtained results. Earlier works have focused on the differences in the sidelobe estimation obtained by GO and PO. The present work presents a comparison of both methods in terms of cross-polarised fields prediction. The study includes both front-fed and offset configurations, using both linearly and circularly polarised feeds and exploits in-house GO and PO tools as well as commercial PO software.
GeoJournal, 2022
Smart city approaches have tended to be top-down, techno-centric/corporate and expensive approach... more Smart city approaches have tended to be top-down, techno-centric/corporate and expensive approaches which are promoted by large, global companies. Smart city narratives focus on their expected capacity to improve citizens’ quality of life. However, can technology-driven and municipally-led smart city initiatives address the issues faced by poor and vulnerable communities in urban and peri-urban areas? This paper explores key aspects of the implementation of smart city approaches in the Global South taking as a case study the Colombian city of Medellín, which has been recognized internationally for its social innovation and is considered a smart city by the Inter-American Development Bank. The paper draws on a local, national and international literature review; interviews with key local stakeholders involved in smart city initiatives; and an international workshop on smart cities and community data management organized by the authors in Medellín and bringing together three perspecti...
Computers and Geotechnics, Oct 1, 2023
Vadose Zone Journal, 2019
Proceedings of the Third International Conference on Railway Technology: Research, Development and Maintenance, Mar 10, 2016
CRC Press eBooks, Sep 13, 2012
The running of high-speed trains on ballasted railway tracks requires excellent track geometry an... more The running of high-speed trains on ballasted railway tracks requires excellent track geometry and reliability. Three-dimensional polyurethane GeoComposites have been used at many sites across the United Kingdom (UK) to help solve traditional ballast maintenance issues that arise at critical track assets like switch and crossings and transition zones. This paper presents work done on the technique and shows the results of laboratory tests and real site application. In particular the paper concentrates on the application of the technology to transition zones. The issues surrounding transition zone dynamics are discussed and the problem is analyzed through the results of advanced 3-dimensional finite element modeling using the DART3D software. The simulations presented in this paper show how the transition fault develops and how the track stiffness is affected by different transition attributes, such as voiding and track stiffness changes. The use of polyurethane GeoComposite technology for high-speed transition zone reinforcement is then presented and the results of simulations shown as to its effectiveness.
Social Science Research Network, 2022
Soils and Foundations, Jun 1, 2023
Geomechanics for Energy and the Environment, Mar 1, 2023
CRC Press eBooks, Jun 19, 2009
In this paper the application of polymer geocomposite technology to the reduction/elimination of ... more In this paper the application of polymer geocomposite technology to the reduction/elimination of long standing railway track faults is presented. The polymers used are urethane cross linked polymers that are applied directly to the ballast matrix using on site mixing equipment. Application of the urethane cross linked polymers allows a high degree of visco-elasticity and hence polymer damping characteristics. The formed structure cures within seconds to form a resilient and very strong polymer/ballast geocomposite. The paper describes how the polymer improves the engineering properties of the in situ ballast and presents typical laboratory studies on engineering behavior. Finite element simulations of railway track response before and after polymer application are included to show how the polymer geocomposite behaves under actual train loading. A typical application of the technique to a highspeed, high axle load switch and crossing on the UK West Coast Main Line is described.
International Journal of Geomechanics, Apr 1, 2023
Engineering Geology, Jul 1, 2023
Geometrical Optics (GO) and Physical Optics (PO) have been popular methods to analyse reflector a... more Geometrical Optics (GO) and Physical Optics (PO) have been popular methods to analyse reflector antennas. Although both techniques have extensively been used in the literature and are shown to produce overall accurate results, they lead to some differences in the obtained results. Earlier works have focused on the differences in the sidelobe estimation obtained by GO and PO. The present work presents a comparison of both methods in terms of cross-polarised fields prediction. The study includes both front-fed and offset configurations, using both linearly and circularly polarised feeds and exploits in-house GO and PO tools as well as commercial PO software.
GeoJournal, 2022
Smart city approaches have tended to be top-down, techno-centric/corporate and expensive approach... more Smart city approaches have tended to be top-down, techno-centric/corporate and expensive approaches which are promoted by large, global companies. Smart city narratives focus on their expected capacity to improve citizens’ quality of life. However, can technology-driven and municipally-led smart city initiatives address the issues faced by poor and vulnerable communities in urban and peri-urban areas? This paper explores key aspects of the implementation of smart city approaches in the Global South taking as a case study the Colombian city of Medellín, which has been recognized internationally for its social innovation and is considered a smart city by the Inter-American Development Bank. The paper draws on a local, national and international literature review; interviews with key local stakeholders involved in smart city initiatives; and an international workshop on smart cities and community data management organized by the authors in Medellín and bringing together three perspecti...