000004995 001__ 4995
000004995 005__ 20201023115000.0
000004995 0247_ $$2DOI$$a10.3390/geosciences10100418
000004995 037__ $$aSCART-2020-0179
000004995 100__ $$aMartin, Aurélie 
000004995 245__ $$aCharacterizing Stalagmites’ Eigenfrequencies by Combining In Situ Vibration Measurements and Finite Element Modeling Based on 3D Scans
000004995 260__ $$c2020
000004995 520__ $$aA good assessment of the long-term seismic hazard is necessary for the management of critical infrastructure, Seveso or nuclear industries. One way to do this is to evaluate ground motions necessary to break candlestick stalagmites because the presence of undamaged candlestick stalagmites in a specific cave provides invaluable information about the level of ground motions that have not been reached locally. The knowledge of the transfer function of ground motion inside cave compared to the outdoor is necessary to transpose these underground observations to the surface and thus to reassess seismic hazard levels. Effects related to the depth, the size of the rooms and the substratum of the stalagmites must be considered. We undertook an investigation in the Han-sur-Lesse cave (Belgian Ardennes) at less than 100 km E/SE of the Rhine Graben. The first tests of the methods envisaged already give a good overview of the possibilities and precautions to take to avoid damaging the stalagmites. We conducted a 3D scan of stalagmites to measure their shape precisely and to model their natural resonance frequency. The installation of seismic sensors on an metal post (traffic sign post, without sign) without forced excitation shows the feasibility of studying the natural resonance frequency with seismic noise. Finally, simplified numerical modelling of a stalagmite as well as analytic tests show the influence of sensors on frequency measurements (because of their weight) and suggests limiting this effect by putting the sensors lower and favour lighter sensors as much as possible
000004995 536__ $$a3Fullcost/$$c3Fullcost/$$f3Fullcost 
000004995 594__ $$aNO
000004995 6531_ $$acave
000004995 6531_ $$astalagmite
000004995 6531_ $$anatural frequency
000004995 6531_ $$a3D scan
000004995 6531_ $$anumerical modeling
000004995 6531_ $$aambient seismic noise
000004995 700__ $$aLecocq, Thomas 
000004995 700__ $$aHinzen, Klaus-G. 
000004995 700__ $$aCamelbeeck, Thierry 
000004995 700__ $$aQuinif, Yves 
000004995 700__ $$aFagel, Nathalie 
000004995 773__ $$n10$$pGeosciences $$v10$$y2020
000004995 8560_ $$faurelie.martin@observatoire.be
000004995 85642 $$ahttps://www.mdpi.com/2076-3263/10/10/418
000004995 905__ $$apublished in
000004995 980__ $$aREFERD