Site Effects in Unstable Rock Slopes: Dynamic Behavior of the Randa Instability (Switzerland)

Moore, Jeffrey R.; Gischig, Valentin; Burjánek, Jan; Loew, Simon; Fäh, Donat

doi:10.1785/0120110127

Cited by 116 publications

(70 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In particular, there is evidence that seismic ground motion on landslide slopes can be considerably amplified, and such amplification has a directional character (Moore et al, 2011). Such directional effects were seen to be related with topographic, lithologic and structural factors as well as normal mode rock slope vibration (e.g.…”

Section: Discussionmentioning

confidence: 99%

Seismic site response of unstable steep slope using noise measurements: the case study of Xemxija Bay area, Malta

Panzera

D’Amico

Lotteri

et al. 2012

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

Abstract. Landslide phenomena involve the northern coast of Malta, affecting in particular the urban area of Xemxija. Limestones overlying a clayey formation represent the shallower lithotypes that characterize the surficial geology of this area, where lateral spreading phenomena and rockfalls take place.Ambient noise records, processed through spectral ratio techniques, were analysed in order to characterize the dynamic behavior of the rock masses affected by the presence of fractures linked to the landslide body existing in the area. Experimental spectral ratios were also calculated after rotating the horizontal components of the seismic signal, and a direct estimate of the polarization angle was also performed in order to investigate the existence of directional effects in the ground motion.The results of the morphologic survey confirmed the existence of large cliff-parallel fractures that cause cliff-edge and unstable boulder collapses. Such phenomena appear connected to the presence, inside the clay formation, of a sliding surface that was identified through the interpretation of the noise measurement data. The boundaries of the landslide area appear quite well defined by the pronounced polarization effects, trending in the northeastern direction, observed in the fractured zone and in the landslide body in particular.

show abstract

Section: Discussionmentioning

confidence: 99%

Seismic site response of unstable steep slope using noise measurements: the case study of Xemxija Bay area, Malta

Panzera

D’Amico

Lotteri

et al. 2012

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

show abstract

“…Previous numerical simulations have found that topographic amplification factors hardly exceed 2 (Assimaki and Kausel 2007), in particular, pure topographic effects have been found to be considerably smaller than the complex interaction of combined topographic and geologic effects (Geli et al 1988, Sanchez-Sesma and Campillo 1993. Indeed, a fundamental role seems to be played by shallow heterogeneities and impedance contrasts (see e.g., Moore et al 2011) in slope material properties. On the other hand, such shallow impedance contrasts are often clearly visible by high-frequency peaks of the H/V spectral ratios (see e.g., stations S11 and S19 in Figure 3 show significant peaks around 25 Hz and clear shallow impedance contrasts in Figure 6).…”

Section: Discussionmentioning

confidence: 96%

Combining Seismic Noise Techniques for Landslide Characterization

Pilz

Parolai

Bindi

et al. 2013

Pure Appl. Geophys.

View full text Add to dashboard Cite

The strong topographic relief and the presence of weakly consolidated sediments create favorable conditions for the development of landslides around the eastern rim of the Fergana Basin (Central Asia). In summer 2012, a field experiment employing small aperture seismic arrays was carried out on an unstable slope, using ambient vibration recordings. The aim of the study was to constrain the seismic response of a potential future landslide and to map

show abstract

“…Such effects have been revealed by instrumental recordings of seismic ground motion at landslide-prone areas Wasowski, 2007, 2011;Gallipoli and Mucciarelli, 2007;Garambois et al, 2010;Moore et al, 2011).…”

Section: Del Gaudio Et Al: New Developments In Ambient Noise Analmentioning

confidence: 96%

New developments in ambient noise analysis to characterise the seismic response of landslide-prone slopes

Gaudio

Wąsowski

Muscillo

2013

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

We report on new developments in the application of ambient noise analysis applied to investigate the dynamic response of landslide-prone slopes to seismic shaking, with special attention to the directional resonance phenomena recognised in previous studies. These phenomena can be relevant for seismic slope susceptibility, especially when maximum resonance orientation is close to potential sliding directions. Therefore, the implementation of an effective technique for site response directivity detection is of general interest. In this regard methods based on the calculation of horizontal-to-vertical noise spectral ratio (HVNR) are promising. The applicability of such methods is investigated in the area of Caramanico Terme (central Italy), where ongoing accelerometer monitoring of slopes with different characteristics offers the possibility of validation of HVNR analysis. The noise measurements, carried out in different times to test the result repeatability, revealed that sites affected by response directivity persistently show major peaks with a common orientation, consistent with the resonance direction inferred from accelerometer data. In some cases such a directivity turned out parallel to maximum slope direction, but this cannot be considered a systematic feature of slope dynamic response. At sites where directivity is absent, the HVNR peaks do not generally show a preferential orientation, with rare exceptions that could be linked to the presence of temporarily active sources of polarised noise. The observed variations of spectral ratio amplitude can be related to temporal changes in site conditions (e.g. groundwater level/soil water content variations affecting P wave velocity and Poisson's ratio of surficial layer), which can hinder the recognition of main resonance frequencies. Therefore, we recommend conducting simultaneous measurements at nearby sites within the same study area and repeating measurements at different times in order to distinguish significant systematic polarisation caused by site-specific response directivity from polarisation controlled by properties of noise sources. Furthermore, an analysis of persistence in noise recordings of signals with systematic directivity showed that only a portion of recordings contains wave trains having a clear polarisation representative of site directional resonance. Thus a careful selection of signals for HVNR analysis is needed for a correct characterisation of site directional properties

show abstract

Site Effects in Unstable Rock Slopes: Dynamic Behavior of the Randa Instability (Switzerland)

Cited by 116 publications

References 19 publications

Seismic site response of unstable steep slope using noise measurements: the case study of Xemxija Bay area, Malta

Seismic site response of unstable steep slope using noise measurements: the case study of Xemxija Bay area, Malta

Combining Seismic Noise Techniques for Landslide Characterization

New developments in ambient noise analysis to characterise the seismic response of landslide-prone slopes

Contact Info

Product

Resources

About