Tomas M Fernandez-Steeger

Heavy rainfall on February 20, 2010 triggered numerous shallow rapid landslides across Madeira Island. Most failures started asdebris slides or avalanches at high elevations and transformed into debris flows which rushed downslope into populated coastal areas. The exceptional storm event induced multiple landslide types which show the relations of a cascading effect between preceding landslide processes and triggered successive landslide processes. Cascading effects taken place as large-scale shallow landslides were subsequently channelized into debris flows, which in turn transformed into linked-chains of debris flows by the remobilization of older deposits. The cascading effect continued as channelized debris flows abruptly or transitionally diluted into abrasive hyperconcentrated flows, triggering further slope failures by removal of the lateral support of adjacent slopes. At abrupt changes to low flow velocities and low water-tosediment ratios, hyperconcentrated flows formed tem...

At present the pumped-storage hydropower plant Blautal is planned with a unsealed lower basin below the groundwater table in a limestone quarry at the southern margin of the Blautal, about 4 Km east of the karst spring Blautopf. The lower basin will be bordered in the east by a steep 95 m high rock face. Due to the high environmental sensibility minimal impact of basin and groundwater level fluctuations to the vicinity is required. To ensure this a detailed geohydraulic and geotechnical rock mass description is essential for modeling. Therefore, terrestrial laser scanning (TLS) was used to map the quarry and subsequently a high resolution digital elevation model (HRDEM) was established. This allows to perform spatial joint analysis with respect to the distribution of geohydraulic and geotechnical properties of the rock mass in the quarry. The results show a high quality and allow a distributed joint analysis and identification as well as projection of major joints in the quarry. Res...

ABSTRACT During mechanical headings with tunnel boring machines (TBM) in soft rocks (clay stones, silt rocks, etc.), the excavated material often sticks to the cutting tools, cutting wheel or conveying system. This may cause great difficulties in its excavation, transport and reuse or dumping, as well in the course of the construction progress. Responsible are mainly adhesion processes that occur at the interfaces and at the surfaces of the clay minerals and tools. In the frame of the joint project methods for the prediction and quantification, as well as appropriate countermeasures to face the problem of stickiness of the geomaterials and subsequent clogging will be investigated. Therefore, the geoscientific knowledge of interfacial processes and manipulation techniques on a micro- and nanoscale will be linked to the engineering sciences knowledge of macroscale processes and technical requirements.

ABSTRACT Für die Planfeststellung eines Pumpspeicherwerks (PSW) im Bereich des südlichen Blautals (Schwäbische Alb) werden derzeit umfangreiche geologische und geohydraulische Erkundungen durchgeführt, um insbesondere den Unterbeckenstandort im verkarstungsfähigen Malm zu charakterisieren. Die zur Genehmigung stehende Planung sieht als Vorzugsvariante für das Unterbecken vor, dieses ohne Sohl- und Böschungsabdichtungen im Niveau des Grundwasserleiters zu errichten. Diese Bauweise ist in der Bundesrepublik derzeit noch nicht realisiert worden, wodurch entsprechende Praxiserfahrungen fehlen. Ziel der Untersuchungen ist die Erarbeitung einer soliden Datenbasis für die Beurteilung der hydraulischen Verhältnisse im Karstgrundwasserleiter, um die Auswirkungen während der Bau- und Betriebszeit des Speichers auf umliegende Schutzgüter und Trinkwasserbrunnen zu modellieren und zuverlässig prognostizieren zu können. Neben dem geologischen Erkundungsprogramm (fazielle Erkundung und Trennflächenanalyse mittels LiDAR) zur Gebirgscharakterisierung werden umfangreiche hydraulische Versuche (Auffüllversuche, WD-Tests, Leistungspumpversuche, Langzeitpumpversuch) zur Erkundung der Durchlässigkeiten durchgeführt. Die Ergebnisse der Erkundungen fließen in ein 3-dimensionales numerisches Strömungsmodell ein. In diesem Beitrag werden erste Untersuchungsergebnisse vorgestellt und diskutiert. Abstract Extensive geological and hydrogeological investigations have been undertaken for the planned pumped-storage hydroelectric power plant in “Blautal” (Swabian Alb, Germany) in order to characterise the Jurassic karst aquifer in which the lower reservoir will be constructed. The preferred option for the plant setup is to integrate the lower reservoir into the groundwater without sealing. Therefore, in order to reliably predict the impact of the pumped storage plant operations on the surrounding drinking water wells and groundwater dependent ecosystems, a comprehensive database has been developed to assess the hydraulic conditions of the karst aquifer. A large scale geological site investigation was carried out to characterise the rock mass and extensive hydraulic tests were performed in many boreholes. The results of the hydraulic characterisation were then implemented in a three dimensional flow model. In this paper, the first results of the geological and hydrogeological investigations are presented and discussed.

ABSTRACT We studied in a highly fractured Lower Carboniferous carbonate quarry close to Hastenrath (Voreifel, Germany) that provides a good analogue to a fractured carbonate reservoir, two modern techniques to collect data on fracture orientation semi-automatically in the field, and compared them to the results of traditional fracture measurements. Firstly, fractures were measured along several scanlines using a traditional compass and a modern application on an Android smartphone. Overall, the smartphone measurements reflect the same orientation as traditional compass measurements but generate in the same time a much higher number of data. Secondly, terrestrial laser scanning (TLS) was used to measure and visualise the topographic relief of the quarry walls down to centimetre resolution for close-up digital analysis of fractures. With this method, we were able to identify the same fracture groups as identified in the manually measured scanlines. All measurements indicate two dominant NE SW and NW SE striking fracture sets, regardless of the technique. An additional W E striking set is indicated immediately in the footwall of the Sandgewand Fault. Furthermore, fault-related fracturing is indicated by an increase of fracture densities towards the Sandgewand Fault. In addition to the fractures, minor NW SE striking faults were also observed in the Hastenrath quarry, some with tens of metres of displacement. Locally horizontal slickensides overprint earlier down-slip movement. Based on dextral slickensides on these fault surfaces oriented parallel to the large Sandgewand Fault, we assume that the latter also had a late dextral strike-slip motion component. Based on the results presented in this paper, we conclude that smartphone measurements of fractures and terrestrial laser scanning are appropriate tools to analyse fracture networks in reservoir analogues in a rapid and accurate way.

ABSTRACT Building the lower basin of a pumped-storage hydropower plant in an active limestone quarry without any sealing is a challenging project. A proper site investigation is crucial to increase the overall efficieny of planning as well as realisation by anticipating potential problems and sticking points. The local geology comprises a complex system of reef structures and bedded sequences that is intersected by faults. Sets of faults can be identified on different scales and the fracturing patterns vary vertically and horizontally. Both the ongoing quarrying as well the sheer size and steepness of the outcrop prevent any extensive data acquisition using traditional methods. Therefore, terrestrial laser scanning (TLS) was used to map the quarry and to create a high resolution digital elevation model (HRDEM). The HRDEM allows to perform spatial analysis with respect to the distribution of geohydraulic and geotechnical properties of the rock mass in the quarry. The major advantages of this approach are the increased level of detail, a substantial improvement of documentation and synergetic effects that arise from the multiple different applications of scan data e.g. for analysis, interpretation, planning and solving geohydraulic and geotechnical issues. It has shown in practice that this multi-facetted usage of the collected data outweighs the initial efforts of data collection and processing by far.

After the 2007 wildfires in the western Peloponnese (Greece) we started an investigation in 2009 in this area at different sites, aiming at the reconstruction of different landslide types and to investigate the relation between fire-induced deforestation and landslides. The village Frixa, particularly its southern part, has massive problems with big rotation slides, shallow slides and erosional features. Tertiary Flysch units and Neogene deposits in the Pyrgos area are generally landslide prone. The slopes in the area have the typical ...

The world-wide coal reserves can satisfy the world's primary energy demand for several hundred years. However, deep coal deposits with seams of low thickness and structural complexity do currently not allow an economic exploitation of many deposits. Here, underground coal gasification (UCG) can offer an economical approach for coal extraction. The intended overall process relies on coal deposit exploitation using directed drillings located at the coal seam base and the subsequent in situ coal conversion into a synthesis gas. The resulting synthesis gas is used for electricity generation in a combined cycle plant at the surface. A reduction of the CO2 emissions resulting from the combined process is realized by subsequent CO2 capture and its injection into the previously gasified coal seams. The scope of the present study was the investigation of UCG-CCS competitiveness on the European energy market and the determination of the impacting factors. For that purpose, a modular model for calculation of UCG-CCS electricity generation costs was implemented and adapted to the most relevant process parameters. Furthermore, the range of energy supply coverage was estimated based on different German energy generation scenarios.

This study focuses on the adoption of a modern, widely-used Terrestrial Laser Scanner (TLS) application to investigate volcanic rock slopes in Ribeira de João Gomes valley (Funchal, Madeira island). The TLS data acquisition in May and December 2008 provided information for a characterization of the volcanic environment, detailed structural analysis and detection of potentially unstable rock masses on a slope. Using this information, it was possible to determine specific parameters for numerical rockfall simulations such as average block size, shape or potential sources. By including additional data, such as surface roughness, the results from numerical rockfall simulations allowed us to classify different hazardous areas based on run-out distances, frequency of impacts and related kinetic energy. Afterwards, a monitoring of hazardous areas can be performed in order to establish a rockfall inventory.