Railway freight transport and logistics: Methods for relief, algorithms for verification and proposals for the adjustment of tunnel inner surfaces

In Europe, the attention to efficiency and safety of international railway freight transport has grown in recent years and this has drawn attention to the importance of verifying the clearance between vehicle and lining, mostly when different and variable rolling stock types are expected. This work consists of defining an innovative methodology, with the objective of surveying the tunnel structures, verifying the clearance conditions, and designing a retrofitting work if necessary. The method provides for the use of laser scanner, thermocameras, and ground penetrating radar to survey the geometrical and structural conditions of the tunnel; an algorithm written by the authors permits to verify the clearances. Two different types of works are possible if the inner tunnel surfaces interfere with the profile of the rolling stock passing through: modification of the railroad track or modification of the tunnel intrados by mean milling of its lining. The presented case study demonstrates that the proposed methodology is useful for verifying compatibility between the design vehicle gauge and the existing tunnel intrados, and to investigate the chance to admit rolling stocks from different states. Consequently, the results give the railway management body a chance to perform appropriate measurements in those cases where the minimum clearance requirements are not achieved

EXPERIMENTAL AND NUMERICAL MODELING OF WIND FLOW OVER COMPLEX TOPOGRAPHY

Wind mapping is of utmost importance in various wind engineering, wind environment, and wind energy applications. The available wind atlases usually provide wind data with low resolutions relative to the wind turbine height and size and usually neglect the effect of topographic features with relatively large or sudden changes in elevation. Developing a cost effective methodology to predict the wind patterns and to obtain wind maps over any topographic terrain is absolutely needed for wind turbine/farm siting. As the previous analytic and empirical attempts to resolve the flow over topographic features were limited to basic geometries that hardly exist in nature, applying Particle Image Velocimetry (PIV) measurement techniques in wind tunnel and Computational Fluid Dynamics (CFD) techniques in numerical simulation of the flow over topography seems to be the best alternative solution to the problem. PIV measurements and CFD simulations are carried out on a 1:3000 scale model of complex topographic area. Three distinct topographic features are investigated: a valley, a ridge and a hill. The PIV measurements compare well with hot-wire based mean velocity profiles for the three cases. Moreover, the turbulence intensity profiles match well for flow regions without recirculation. The ridge wake region shows discrepancies between the two techniques which are attributed to the complexity of the flow in this region and limitations of both techniques. A procedure incorporating Geographic Information System (GIS) and surface modeling techniques is introduced to build the CFD model of a complex terrain starting from the existing topography maps with desired resolutions. Moreover, a new approach is made to simulate the terrain roughness up to ultimate roughness heights, by implementing arrays of bell-shaped roughness elements in the CFD model. The velocity profiles and velocity vectors were compared with the PIV measurements and were found to be in good agreement near the ground and up to the full scale height of 300m. The study shows that PIV measurements and CFD simulations can be successfully used in qualifying and quantifying the flow over complex topography consisting of a wide range of roughness heights, enabling to map the flow structure with very high spatial resolution

A review of the use of terrestrial laser scanning application for change detection and deformation monitoring of structures

Change detection and deformation monitoring is an active area of research within the field of engineering surveying as well as overlapping areas such as structural and civil engineering. The application of Terrestrial Laser Scanning (TLS) techniques for change detection and deformation monitoring of concrete structures has increased over the years as illustrated in the past studies. This paper presents a review of literature on TLS application in the monitoring of structures and discusses registration and georeferencing of TLS point cloud data as a critical issue in the process chain of accurate deformation analysis. Past TLS research work has shown some trends in addressing issues such as accurate registration and georeferencing of the scans and the need of a stable reference frame, TLS error modelling and reduction, point cloud processing techniques for deformation analysis, scanner calibration issues and assessing the potential of TLS in detecting sub-centimetre and millimetre deformations. However, several issues are still open to investigation as far as TLS is concerned in change detection and deformation monitoring studies such as rigorous and efficient workflow methodology of point cloud processing for change detection and deformation analysis, incorporation of measurement geometry in deformation measurements of high-rise structures, design of data acquisition and quality assessment for precise measurements and modelling the environmental effects on the performance of laser scanning. Even though some studies have attempted to address these issues, some gaps exist as information is still limited. Some methods reviewed in the case studies have been applied in landslide monitoring and they seem promising to be applied in engineering surveying to monitor structures. Hence the proposal of a three-stage process model for deformation analysis is presented. Furthermore, with technological advancements new TLS instruments with better accuracy are being developed necessitating more research for precise measurements in the monitoring of structures

Integrated Photogrammetric-Acoustic Technique for Qualitative Analysis of the Performance of Acoustic Screens in Sandy Soils

[EN] In this work, we present an integrated photogrammetric-acoustic technique that, together with the construction of a scaled wind tunnel, allows us to experimentally analyze the permeability behavior of a new type of acoustic screen based on a material called sonic crystal. Acoustic screens are devices used to reduce noise, mostly due to communication infrastructures, in its transmission phase from the source to the receiver. The main constructive difference between these new screens and the classic ones is that the first ones are formed by arrays of acoustic scatterers while the second ones are formed by continuous walls. This implies that, due to their geometry, screens based on sonic crystals are permeable to wind and water, unlike the classic ones. This fact may allow the use of these new screens in sandy soils, where sand would pass through the screen, avoiding the formation of sand dunes that are formed in classic screens and drastically reducing their acoustic performance. In this work, the movement of the sand and the resulting acoustic attenuation in these new screens are analyzed qualitatively, comparing the results with those obtained with the classic ones, and obtaining interesting results from the acoustic point of view.Bravo, JM.; Buchón Moragues, FF.; Redondo, J.; Ferri García, M.; Sánchez Pérez, JV. (2019). Integrated Photogrammetric-Acoustic Technique for Qualitative Analysis of the Performance of Acoustic Screens in Sandy Soils. Sensors. 19(22):1-17. https://doi.org/10.3390/s19224881S1171922Castiñeira-Ibañez, S., Rubio, C., & Sánchez-Pérez, J. V. (2015). Environmental noise control during its transmission phase to protect buildings. Design model for acoustic barriers based on arrays of isolated scatterers. Building and Environment, 93, 179-185. doi:10.1016/j.buildenv.2015.07.002Fredianelli, L., Del Pizzo, A., & Licitra, G. (2019). Recent Developments in Sonic Crystals as Barriers for Road Traffic Noise Mitigation. Environments, 6(2), 14. doi:10.3390/environments6020014Martínez-Sala, R., Sancho, J., Sánchez, J. V., Gómez, V., Llinares, J., & Meseguer, F. (1995). Sound attenuation by sculpture. Nature, 378(6554), 241-241. doi:10.1038/378241a0Morandi, F., Miniaci, M., Marzani, A., Barbaresi, L., & Garai, M. (2016). Standardised acoustic characterisation of sonic crystals noise barriers: Sound insulation and reflection properties. Applied Acoustics, 114, 294-306. doi:10.1016/j.apacoust.2016.07.028Castiñeira-Ibáñez, S., Rubio, C., Romero-García, V., Sánchez-Pérez, J. V., & García-Raffi, L. M. (2012). Design, Manufacture and Characterization of an Acoustic Barrier Made of Multi-Phenomena Cylindrical Scatterers Arranged in a Fractal-Based Geometry. Archives of Acoustics, 37(4), 455-462. doi:10.2478/v10168-012-0057-9Sanchez-Perez, J. V., Castineira-Ibanez, S., Romero-Garcia, V., & Garcia-Raffi, L. M. (2015). PERIODIC SYSTEMS AS ROAD TRAFFIC NOISE REDUCING DEVICES: PROTOTYPE AND STANDARDIZATION. Environmental Engineering and Management Journal, 14(12), 2759-2769. doi:10.30638/eemj.2015.293Wang, Y.-F., Wang, Y.-S., & Laude, V. (2015). Wave propagation in two-dimensional viscoelastic metamaterials. Physical Review B, 92(10). doi:10.1103/physrevb.92.104110Wang, Y.-F., Liang, J.-W., Chen, A.-L., Wang, Y.-S., & Laude, V. (2019). Wave propagation in one-dimensional fluid-saturated porous metamaterials. Physical Review B, 99(13). doi:10.1103/physrevb.99.134304Valkenburg, R. J., & McIvor, A. M. (1998). Accurate 3D measurement using a structured light system. Image and Vision Computing, 16(2), 99-110. doi:10.1016/s0262-8856(97)00053-xHui, Z., Liyan, Z., Hongtao, W., & Jianfu, C. (2009). Surface Measurement Based on Instantaneous Random Illumination. Chinese Journal of Aeronautics, 22(3), 316-324. doi:10.1016/s1000-9361(08)60105-3McPherron, S. P., Gernat, T., & Hublin, J.-J. (2009). Structured light scanning for high-resolution documentation of in situ archaeological finds. Journal of Archaeological Science, 36(1), 19-24. doi:10.1016/j.jas.2008.06.028Bruno, F., Bianco, G., Muzzupappa, M., Barone, S., & Razionale, A. V. (2011). Experimentation of structured light and stereo vision for underwater 3D reconstruction. ISPRS Journal of Photogrammetry and Remote Sensing, 66(4), 508-518. doi:10.1016/j.isprsjprs.2011.02.009Bertani, D. (1995). High-resolution optical topography applied to ancient painting diagnostics. Optical Engineering, 34(4), 1219. doi:10.1117/12.196545Buchón-Moragues, F., Bravo, J., Ferri, M., Redondo, J., & Sánchez-Pérez, J. (2016). Application of Structured Light System Technique for Authentication of Wooden Panel Paintings. Sensors, 16(6), 881. doi:10.3390/s16060881Arias, P., Herráez, J., Lorenzo, H., & Ordóñez, C. (2005). Control of structural problems in cultural heritage monuments using close-range photogrammetry and computer methods. Computers & Structures, 83(21-22), 1754-1766. doi:10.1016/j.compstruc.2005.02.018Rocchini, C., Cignoni, P., Montani, C., Pingi, P., & Scopigno, R. (2001). A low cost 3D scanner based on structured light. Computer Graphics Forum, 20(3), 299-308. doi:10.1111/1467-8659.00522Bianchi, M. G., Casula, G., Cuccuru, F., Fais, S., Ligas, P., & Ferrara, C. (2018). Three-dimensional imaging from laser scanner, photogrammetric and acoustic non-destructive techniques in the characterization of stone building materials. Advances in Geosciences, 45, 57-62. doi:10.5194/adgeo-45-57-2018Alvarez, L., Moreno, H., Segales, A., Pham, T., Pillar-Little, E., & Chilson, P. (2018). Merging Unmanned Aerial Systems (UAS) Imagery and Echo Soundings with an Adaptive Sampling Technique for Bathymetric Surveys. Remote Sensing, 10(9), 1362. doi:10.3390/rs10091362Miller, B. S., Wotherspoon, S., Rankin, S., Calderan, S., Leaper, R., & Keating, J. L. (2018). Estimating drift of directional sonobuoys from acoustic bearings. The Journal of the Acoustical Society of America, 143(1), EL25-EL30. doi:10.1121/1.5020621Zhang, D., Li, S., Bai, X., Yang, Y., & Chu, Y. (2019). Experimental Study on Mechanical Properties, Energy Dissipation Characteristics and Acoustic Emission Parameters of Compression Failure of Sandstone Specimens Containing En Echelon Flaws. Applied Sciences, 9(3), 596. doi:10.3390/app9030596Hartley, R. I., & Schaffalitzky, F. (2009). Reconstruction from Projections Using Grassmann Tensors. International Journal of Computer Vision, 83(3), 274-293. doi:10.1007/s11263-009-0225-1Ahmadabadian, A. H., Robson, S., Boehm, J., Shortis, M., Wenzel, K., & Fritsch, D. (2013). A comparison of dense matching algorithms for scaled surface reconstruction using stereo camera rigs. ISPRS Journal of Photogrammetry and Remote Sensing, 78, 157-167. doi:10.1016/j.isprsjprs.2013.01.015Olague, G., & Dunn, E. (2007). 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Wind characteristics over complex terrain: laboratory simulation and field measurements at Rakaia Gorge, New Zealand: final report, part II

CER77-78RNM29.Prepared for the United States Department of Energy, Division of Solar Technology, Federal Wind Energy Program.DOE contract no. EY-76-S06-2438, A001.Includes bibliographical references (pages 93-102).May 1978

Aeronautical Engineering. A continuing bibliography, supplement 115

This bibliography lists 273 reports, articles, and other documents introduced into the NASA scientific and technical information system in October 1979

New Advances in Fluid Structure Interaction

Fluid–structure interactions (FSIs) play a crucial role in the design, construction, service and maintenance of many engineering applications, e.g., aircraft, towers, pipes, offshore platforms and long-span bridges. The old Tacoma Narrows Bridge (1940) is probably one of the most infamous examples of serious accidents due to the action of FSIs. Aircraft wings and wind-turbine blades can be broken because of FSI-induced oscillations. To alleviate or eliminate these unfavorable effects, FSIs must be dealt with in ocean, coastal, offshore and marine engineering to design safe and sustainable engineering structures. In addition, the wind effects on plants and the resultant wind-induced motions are examples of FSIs in nature. To meet the objectives of progress and innovation in FSIs in various scenarios of engineering applications and control schemes, this book includes 15 research studies and collects the most recent and cutting-edge developments on these relevant issues. The topics cover different areas associated with FSIs, including wind loads, flow control, energy harvesting, buffeting and flutter, complex flow characteristics, train–bridge interactions and the application of neural networks in related fields. In summary, these complementary contributions in this publication provide a volume of recent knowledge in the growing field of FSIs