9762 papers found
This paper presents an experimentation, which has been conducted in the underwater archaeological site of Capo Colonna, aimed to verify the joined use of optical and acoustic techniques for the generation of multi-resolution textured 3D models of underwater sites, obtained by merging the results of surveys carried out with these two types of systems.
The industry of submarine cables, both for power connection and for telecommunication (TLC) has experienced growing development in recent years and these assets have become strategic. We describe here the main methods and procedures that are followed during geophysical and geological investigations (site surveys) preparatory to the installation of submarine cables.
Submarine geotechnical exploration is a challenging task that is currently undergoing a paradigm change thanks to robotics and teleoperation. The MD500 Project is an underwater subsea geotechnical drilling and in situ testing device designed to sample and probe up to 150 m of soils of rock beneath the seabed in water depths of up to 500 m. The system has applications in several areas of marine activity, such as port infrastructure, nearshore and offshore renewable energy projects, oil & gas, submarine mining, etc. The machine consists of a group of devices operated remotely and that must...
The 5 km wide Banco della Montagna (BdM) morphological high is located on the seafloor of Naples Bay (Tyrrhenian Sea, Italy) and is characterized by a hummocky surface. Oceanographic surveys revealed active fluid vents at BdM. High-resolution mono-channel seismic and multibeam bathymetry allow us to define the detailed morphology and the inner geometry of BdM, which consists of a complex set of dome-like structures (pagodas) affecting the present-day seabed. We suggest that a gas-water-sand sediment mixture upraises from a gas saturated layer pushing up the overlying marine deposits and...
The development of dedicated software has opened a new frontier in Earth Sciences, leading to a more accurate spatial analysis of geological structures and to 3D geospatial models. We studied the offshore of the Salento Peninsula (Italy) that is part of the stable Apulian foreland of the Southern Apennines thrust belt. We interpreted a seismic grid, calibrated by borehole data, using seismic stratigraphy and structural geology approaches in a dedicated GIS environment. We built 2-D models of relevant geological surfaces and 3-D digital models of the subsurface showing NW-SE and NNW-SSE...
This paper presents an overview of achievements and hurdles in international standardisation of geotechnical practice for in situ testing and offshore geophysical survey. Standardisation of in situ testing is progressing from a historic, specification-type approach to a performance-based approach. The tools for actual demonstration of achieving the performance-based requirements for accuracy are shown to be lagging behind. Work is now underway for standardisation of sub-seafloor geophysical surveys for geotechnical applications. Standardisation of metrology issues proves challenging. The...
Surface dam monitoring has been always based on traditional surveying techniques that are time consuming and characterized by some limitations in space coverage and frequency. More recently DInSAR (Differential Synthetic Aperture Radar Interferometry) satellite-based technologies allow us to integrate and improve the monitoring capabilities provided by ground-based methods, thanks to their effectiveness to measure displacements on reflecting elements of the structure, acting as non-destructive control points. Therefore the availability of a large number of measurements points distributed...
This paper presents selected results from the study on the seismic behaviour of a large earth dam. The study relies on the availability of field and laboratory tests, as well as on monitoring data collected during the construction and impounding phases. Specifically, a two- dimensional numerical model was calibrated by comparing the settlements of the dam measured during the construction with the computed values. Iterative pseudo-static numerical analyses were carried out to investigate the plastic mechanisms forming under critical conditions. The seismic performance of the dam was then...
The Farneto del Principe dam in southern Italy is a critical infrastructure, equipped with a complete monitoring system. Over the years, the effectiveness of this system has been drastically reduced, mainly due to a consistent number of malfunctioned piezometers. A substantial geotechnical investigation campaign was performed in 2015, and new piezometers installed. They are beneficial for supplementing monitoring data and enhance the reliability of the old monitoring system. This paper describes the results from standard geotechnical laboratory and chemical-physical tests, as well as first...
The paper describes the preliminary results of ground-based and remote sensing techniques applied to monitor the displacements and seepage flow of a bituminous faced rockfill dam located on the Aspromonte mountain in southern Italy (Menta Dam). The analysis and interpretation of the seepage flow highlighted the overall good performance of the dam during the first impoundment. Moreover, the application of Differential Interferometric Synthetic Aperture Radar technique for measuring the dam’s displacements produced fairly good results, highlighting the effectiveness of remote sensing...