Kollisionssicherheit TRANSRAPID. Teilbericht LF4: Horizontal liegender Baum

Available from TIB Hannover: RR 4849(3579,04) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Kollisionssicherheit TRANSRAPID. Teilbericht LF2: 50 kg-Stein mitten auf dem Fahrweg

Available from TIB Hannover: RR 4849(3579,02) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Kollisionssicherheit TRANSRAPID. Teilbericht: Fahrgastbeschleunigungen

Available from TIB Hannover: RR 4849(3579,08) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Kollisionssicherheit TRANSRAPID. Teilbericht LF7: Anprall Strassenfahrzeug/Fahrwergtraeger

Available from TIB Hannover: RR 4849(3579,07) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Kollisionssicherheit TRANSRAPID. Teilbericht LF1: 15 kg-Stein auf der Gleitleiste

Available from TIB Hannover: RR 4849(3579,01) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Kollisionssicherheit TRANSRAPID. Teilbericht LF5: Kollision 50 kg-Stein/Tragmagnet

Available from TIB Hannover: RR 4849(3579,05) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Location of microseismic swarms induced by salt solution mining

International audienceGround failures, caving processes and collapses of large natural or man-made underground cavities can produce significant socio-economic damages and represent a serious risk envisaged by the mine managements and municipalities. In order to improve our understanding of the mechanisms governing such a geohazard and to test the potential of geophysical methods to prevent them, the development and collapse of a salt solution mining cavity was monitored in the Lorraine basin in northeastern France. During the experiment, a huge microseismic data set (similar to 50 000 event files) was recorded by a local microseismic network. 80 per cent of the data comprised unusual swarming sequences with complex clusters of superimposed microseismic events which could not be processed through standard automatic detection and location routines. Here, we present two probabilistic methods which provide a powerful tool to assess the spatio-temporal characteristics of these swarming sequences in an automatic manner. Both methods take advantage of strong attenuation effects and significantly polarized P-wave energies at higher frequencies (>100 Hz). The first location approach uses simple signal amplitude estimates for different frequency bands, and an attenuation model to constrain the hypocentre locations. The second approach was designed to identify significantly polarized P-wave energies and the associated polarization angles which provide very valuable information on the hypocentre location. Both methods are applied to a microseismic data set recorded during an important step of the development of the cavity, that is, before its collapse. From our results, systematic spatio-temporal epicentre migration trends are observed in the order of seconds to minutes and several tens of meters which are partially associated with cyclic behaviours. In addition, from spatio-temporal distribution of epicentre clusters we observed similar epicentre migration in the order of hours and days. All together, we suggest that the recorded microseismicity mainly represents detachment and block breakage processes acting at the cavity's roof, indicating a zone of critical state of stress and where partial fractures cause chain reaction failures as a result of stress redistribution processes

The largest induced earthquakes during the GEOVEN deep geothermal project, Strasbourg, 2018-2022: from source parameters to intensity maps

International audienceBetween 2019 November and 2021 July, four induced earthquakes of local magnitude equal to or greater than than three were felt by the population of Strasbourg, France. These events were related to activity at the deep geothermal site GEOVEN located in Vendenheim in the northern suburb area of the city of Strasbourg. The first earthquake, with a local magnitude (Mlv) of 3.0, occurred on 2019 November 12, at the same depth as the bottom of the wells (approximately 4 km) but 5 km to the south. The second (Mlv 3.6) occurred a year later, on 2020 December 4, below the wells, and led to the termination of the project by the authorities. The third (Mlv 3.3) was initiated three weeks after shut-in on 2021 January 22, while the largest earthquake to date (Mlv 3.9) occurred on 2021 June 26, more than 6 months after shut-in. We constrained these four events' absolute locations using a 3-D velocity model of the area and here present regional intensity maps. We estimated moment magnitude and focal mechanism trough waveform inversion and inferred the fault plane activated during the largest event from an analysis of rupture directivity effects in the recorded waveforms. Our analysis highlights the existence of a critically stressed fault that hosted three of these widely felt events. We show how the derived source properties of these four earthquakes are directly linked to ground shaking observations at the surface. Notably, we demonstrate how earthquake moment, location, direction of rupture and stress drop impact the regional intensity distribution. Our results suggest that the traffic light system could benefit from including ground shaking scenarios based on realistic subsurface properties and potential earthquake source models