<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The present study shows the results of a 2D local seismic response (LSR) analysis, simulated for a geomechanical model consisting of a layered carbonate rock mass with hypogean karst caves and a structural–lithostratigraphic complex setting, in an area within the Municipality of Turi (Apulia, Italy). In this case study a Distinct Element Code (DEM) code (UDEC) was used for the LSR simulations conducted on a model both in the absence and in the presence of two overlapping karst caves. The preliminary stress–strain model analysis show some tensile yielding points clustered on the roof of the upper karst cave, already in static conditions, and the phenomenon becomes even more noticeable in dynamic conditions. This is perfectly in agreement with the real occurrence of a sinkhole that brought to the light the underlying karst cave, in the case study area, in the recent past.</p><p>The amplification/deamplification factor (FA) was calculated as the ratio of the top value to the bottom value in the model, both of the max X-acceleration and of the spectral Fourier amplitude in three different ranges of frequencies, in order to estimate the effects of LSR on the X-component of the seismic input. According to the previous studies, the results obtained show a generalised deamplification of the seismic ground motion at the top of the model, both without and with underground karst caves, caused by the presence of the upper karst cave and by the seismic energy absorption because of layers’ discontinuity.</p></abstract>

The present study shows the results of a 2D local seismic response (LSR) analysis, simulated for a geomechanical model consisting of a layered carbonate rock mass with hypogean karst caves and a structural–lithostratigraphic complex setting, in an area within the Municipality of Turi (Apulia, Italy). In this case study a Distinct Element Code (DEM) code (UDEC) was used for the LSR simulations conducted on a model both in the absence and in the presence of two overlapping karst caves. The preliminary stress–strain model analysis show some tensile yielding points clustered on the roof of the upper karst cave, already in static conditions, and the phenomenon becomes even more noticeable in dynamic conditions. This is perfectly in agreement with the real occurrence of a sinkhole that brought to the light the underlying karst cave, in the case study area, in the recent past.The amplification/deamplification factor (FA) was calculated as the ratio of the top value to the bottom value in the model, both of the max X-acceleration and of the spectral Fourier amplitude in three different ranges of frequencies, in order to estimate the effects of LSR on the X-component of the seismic input. According to the previous studies, the results obtained show a generalised deamplification of the seismic ground motion at the top of the model, both without and with underground karst caves, caused by the presence of the upper karst cave and by the seismic energy absorption because of layers’ discontinuity.

2D numerical analysis of the seismic response of a karst rock mass: importance of underground caves and geostructural details

Politecnico di Bari, Department of Civil, Environmental, Land, Building Engineering and Chemistry

Studia Geotechnica et Mechanica

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

The present study shows the results of a 2D local seismic response (LSR) analysis, simulated for a geomechanical model consisting of a layered carbonate rock...

2D numerical analysis of the seismic response of a karst rock mass: importance of underground caves and geostructural details

Article Category: Research Article

Published Online: Mar 19, 2020

Page range: 61 - 73

Received: Apr 12, 2019

Accepted: Aug 21, 2019

DOI: https://doi.org/10.2478/sgem-2019-0028

Keywords
2D local seismic response analysis, rock mass, karstic underground caves

© 2020 Bruno Giovanni et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

2D numerical analysis of the seismic response of a karst rock mass: importance of underground caves and geostructural details

Article Category: Research Article

Published Online: Mar 19, 2020

Page range: 61 - 73

Received: Apr 12, 2019

Accepted: Aug 21, 2019

DOI: https://doi.org/10.2478/sgem-2019-0028

Keywords2D local seismic response analysis, rock mass, karstic underground caves

© 2020 Bruno Giovanni et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
2D local seismic response analysis, rock mass, karstic underground caves