Seismic compression susceptibility in dry loose sandy and silty soil in a seismic microzonation perspective

Fabozzi, Stefania; Porchia, Attilio; Fierro, Tony; Peronace, Edoardo; Pagliaroli, Alessandro; Moscatelli, Massimiliano

doi:10.1016/j.enggeo.2019.105324

Cited by 6 publications

(3 citation statements)

References 15 publications

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“…The results obtained from this preliminary analysis confirms the possibility to model a 1D column characterized by a generic lithostratigraphic succession with an equivalent one representative of a geological-technical unit within the SM without introducing significative errors. However, to get more general conclusions, we need to extend this study to a significant number of cases to take into account the high vertical variability typical of the subsoil conditions (Rathje et al, 2010;Kaklamanos et al, 2013;Pagliaroli et al, 2014a,b;Kim et al, 2016;Foti et al, 2019;Fabozzi et al, 2019aFabozzi et al, , 2019b. For the scope, an extensive parametric analysis is discussed hereinafter ( §3 and §4), with reference to the cases of sand-silt and sand-gravel 1D lithostratigraphic successions.…”

Section: Preliminary Analysismentioning

confidence: 99%

The possible use of equivalent homogeneous subsoil models for 1D seismic response analyses in seismic microzonation studies

Fabozzi

Albarello

Pagliaroli

et al. 2022

Bull Earthquake Eng

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The possibility is here explored to use an 'equivalent' homogeneous configuration to simulate 1D seismic response of heterogeneous engineering-geological bodies when relatively weak seismic impedance contrasts (≤150 m/s) only exist above the seismic bedrock. This equivalent configuration is obtained by considering an equivalent Vs value the harmonic average of the actual Vs values and a linear combination of G/G0 and D curves relative to the lithotechnical components present in the actual configuration. To evaluate feasibility of this approach, a wide set of numerical simulations was carried out by randomly generating subsoil layering including sequences of alternating thin layers of geotechnical units (e.g., sands and clays) each characterized by a characteristic nonlinear curve. Outcomes of these simulations are compared with those provided by considering a single homogeneous layer characterized by equivalent nonlinear curves obtained as a weighted average of the original curves. By comparing the heterogeneous and the homogeneous columns seismic response in terms of amplification factors and fundamental period, the results confirm the possibility to model a 1D column characterized by a generic lithostratigraphic succession with an equivalent one without introducing significative errors that, at least for the studied cases, do not exceed the 6%. This conclusion is substantially confirmed by extending the comparison to a real case, i.e. the 113 m-thick heterogeneous soil profile at Mirandola site (Norther Italy), presented in the last part. INTRODUCTIONAccounting for nonlinear behavior of soil under dynamic loads is necessary to provide a consistent modelling of local seismic response during strong earthquakes (Kramer, 1996). Two methods of analysis can essentially be chosen to this purpose: equivalent linear, based on a series of iterative analyses assuming a visco-elastic soil behavior, or a true nonlinear approach, this latter involving a broad range of simplified (i.e., hyperbolic family models) and advanced soil constitutive models (Hashash et al., 2010). The nonlinear curves, i.e. the normalized shear modulus (G/G0-g) and the damping ratio (D-g) curves, are directly employed in the equivalent linear strategy or used to calibrate the constitutive parameters in the true nonlinear approach. In the Seismic Microzonation (SM) studies the equivalent linear analysis is still the preferred approach because the limited data generally available on cyclic behavior as well as the large number of numerical simulations to be carried out (Pagliaroli, 2018). A crucial step in these analyses is defining variation of shear modulus and damping ratio when excitation strength increases (G/G0-g and D-g curves). These can be obtained ad hoc from laboratory

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Section: Preliminary Analysismentioning

confidence: 99%

The possible use of equivalent homogeneous subsoil models for 1D seismic response analyses in seismic microzonation studies

Fabozzi

Albarello

Pagliaroli

et al. 2022

Bull Earthquake Eng

Self Cite

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Section: De< Fgmentioning

confidence: 99%

The Possible use of Equivalent Homogeneous Subsoil Models for 1D Seismic Response Analyses in Seismic Microzonation Studies

Fabozzi

Albarello

Pagliaroli

et al. 2021

Preprint

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The possibility is here explored to use an ‘equivalent’ homogeneous configuration to simulate 1D seismic response of heterogeneous engineering-geological bodies when relatively weak seismic impedance contrasts (150 m/s) only exist above the seismic bedrock. This equivalent configuration is obtained by considering an equivalent Vs value the harmonic average of the actual Vs values and a linear combination of G/G 0 and D curves relative to the lithotechnical components present in the actual configuration. To evaluate feasibility of this approach, a wide set of numerical simulations was carried out by randomly generating subsoil layering including sequences of alternating thin layers of geotechnical units ( e.g., sands and clays) each characterized by a characteristic nonlinear curve. Outcomes of these simulations are compared with those provided by considering a single homogeneous layer characterized by equivalent nonlinear curves obtained as a weighted average of the original curves. By comparing the heterogeneous and the homogeneous columns seismic response in terms of amplification factors and fundamental period, the results confirm the possibility to model a 1D column characterized by a generic lithostratigraphic succession with an equivalent one without introducing significative errors that, at least for the studied cases, do not exceed the 6%. This conclusion is substantially confirmed by extending the comparison to a real case, i.e. the 113 m-thick heterogeneous soil profile at Mirandola site (Norther Italy), presented in the last part.

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“…Changes occur in the amplitude of the seismic waves depending on some physical properties of the soil environment in which they spread (Bonnefoy-Claudet et al 2008). Seismic microzonation studies have an important application to prevent earthquake damage for this reason (Fabozzi et al, 2020). Furthermore, understanding the dynamic properties of the soils has a key role in geotechnical problems on the soil (Guler and Afacan, 2019).…”

Section: Introductionmentioning

confidence: 99%

Investigation of the Effects of Waste Tire, Water Content and Relative Density on Soil Dominant Frequency in Separate Grained Soils by Microtremor Method

Cakici¹,

Kocadagistan

Özer

et al. 2022

JER is an international, peer-reviewed journal that publishes f

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This paper presents the effects of the waste tire, water content, and relative density on soil dominant frequency using the experimental application. In this study, metal cylindrical molds with a diameter of 30 cm and a height of 50 cm are prepared to understand the effects of these materials. These molds are filled with sand in different relative densities (60% and 80%). Also; the samples are prepared by adding waste tire particles at different rates (0%, 0.5%, 1%, 2%) to this sand for different relative densities and water contents (0%, 5%, 10%, 15%). The soil dominant frequency and H/V amplitude are determined with the microtremor technique by measuring at 60 minutes of measurement on each cylinder using a broadband seismometer. Microtremor data are analyzed by using the Horizontal/Vertical spectral ratio method. As a result of the experiments, it has been observed that the waste tire particles added to the sand affect the H/V amplitude in a decreasing way. It is detected that the most suitable environment is obtained to be 1% waste tire and 0% water content for 60% relative density. Moreover, the most suitable environment has been achieved in 0% water content and 0.5% waste tire ratio for 80% relative density. It has been concluded that the prepared composite material with waste tires may have positive effects on decreasing the earthquake devastating effects.

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Seismic compression susceptibility in dry loose sandy and silty soil in a seismic microzonation perspective

Cited by 6 publications

References 15 publications

The possible use of equivalent homogeneous subsoil models for 1D seismic response analyses in seismic microzonation studies

The possible use of equivalent homogeneous subsoil models for 1D seismic response analyses in seismic microzonation studies

The Possible use of Equivalent Homogeneous Subsoil Models for 1D Seismic Response Analyses in Seismic Microzonation Studies

Investigation of the Effects of Waste Tire, Water Content and Relative Density on Soil Dominant Frequency in Separate Grained Soils by Microtremor Method

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