A comparative study on seismic response of two unstable rock slopes within same tectonic setting but different activity level

0479851 - GFÚ 2018 RIV GB eng J - Článek v odborném periodiku
Kleinbrod, U. - Burjánek, Jan - Hugentobler, M. - Amann, F. - Fäh, D.
A comparative study on seismic response of two unstable rock slopes within same tectonic setting but different activity level.
Geophysical Journal International. Roč. 211, č. 3 (2017), s. 1428-1448. ISSN 0956-540X. E-ISSN 1365-246X
Institucionální podpora: RVO:67985530
Klíčová slova: seismic noise * site effects * wave propagation
Obor OECD: Volcanology
Impakt faktor: 2.528, rok: 2017

In this study, the seismic response of two slope instabilities is investigated with seismic
ambient vibration analysis. Two similar sites have been chosen: an active deep-seated slope
instability at Cuolm da Vi and the geologically, structurally and morphologically similar, but
presently not moving Alp Caschl`e slope. Both slopes are located at the upper Vorderrheintal
(Canton Graub¨unden, Switzerland). Ambient vibrations were recorded on both slopes and
processed by time–frequency polarization and site-to-reference spectral ratio analysis. The
data interpretation shows correlations between degree of disintegration of the rock mass and
amplification. However, the ambient vibration analysis conducted, does not allow retrieving a
resonance frequency that can be related to the total depth of the instability of Cuolm da Vi.
Even though seismic waves can be hardly traced in rock instabilities containing open fractures,
it was possible to retrieve a dispersion curve and a velocity profile from the array measurement
at Cuolm da Vi due to the high level of disintegration of the rock material down to a depth
of about 100 m. From the similar amplification pattern at the two sites, we expect a similar
structure, indicating that also the slope at Alp Caschl`e was active in the past in a similar manner
as Cuolm da Vi. However, a smoother increase of amplification with frequency is observed at
Alp Caschl`e, which might indicate less disintegration of the rock mass in a particular depth
range at this site, when comparing to Cuolm da Vi where a high level of disintegration is
observed, resulting from the high activity at the slope.

Trvalý link: http://hdl.handle.net/11104/0275777