Effects of topographic irregularity on seismic site amplification considering input signal frequency

A case study

authored by: Zhe Xing Chen, Guan Chen, Yong Liu
Abstract: The topographic amplification effect has significant impacts on structural safety since it causes inconsistencies in seismic response. Previous studies on topographical influence focus on a certain point and cross-sections, which is insufficient to comprehensively understand the topographic amplification effect. Besides, few studies analyze the relationship between seismic response and ground motion frequency. Hence, this study aims to investigate the effects of topographic irregularity of the whole site, and explore the relationship between seismic response characteristics and signal frequency. An analysis procedure for modeling and meshing an actual 3D site is proposed by combining SolidWorks, SketchUp and Abaqus. Finite element method (FEM) is applied to simulate the seismic response. Results show that the site amplification and de-amplification are associated with topographic features. Specifically, the seismic responses of ravine and ridge areas could differ by a factor of two. However, acceleration response in ravine areas shows unusual amplification under input signal frequencies over 4 Hz. Besides, the frequency of input ground motion certainly affects the seismic site amplification. Specifically, in this study, the seismic response peaks when the input frequency is in the range of 0.4–0.8 Hz, which corresponds to the resonance frequency of the numerical model. In terms of frequency, site amplification showed a correlation between actual recordings and artificial signal inputs, but lower intensities are observed when actual records are input. Therefore, the engineering risk will be underestimated when the topographic irregularity and frequency characteristic of input ground motion are inappropriately considered. The findings of this study provide a new approach to investigate the actual 3D site amplification effects and shed new insight on regional seismic risk analysis.
Organisation(s): Institute for Risk and Reliability
External Organisation(s): Wuhan University
Type: Article
Journal: Engineering structures
Volume: 304
No. of pages: 13
ISSN: 0141-0296
Publication date: 01.04.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Civil and Structural Engineering
Electronic version(s): https://doi.org/10.1016/j.engstruct.2024.117667 (Access: Open)

BibTeX

@article{964e4dc5b5d64550b122eba3e94d466a,
title = "Effects of topographic irregularity on seismic site amplification considering input signal frequency: A case study",
abstract = "The topographic amplification effect has significant impacts on structural safety since it causes inconsistencies in seismic response. Previous studies on topographical influence focus on a certain point and cross-sections, which is insufficient to comprehensively understand the topographic amplification effect. Besides, few studies analyze the relationship between seismic response and ground motion frequency. Hence, this study aims to investigate the effects of topographic irregularity of the whole site, and explore the relationship between seismic response characteristics and signal frequency. An analysis procedure for modeling and meshing an actual 3D site is proposed by combining SolidWorks, SketchUp and Abaqus. Finite element method (FEM) is applied to simulate the seismic response. Results show that the site amplification and de-amplification are associated with topographic features. Specifically, the seismic responses of ravine and ridge areas could differ by a factor of two. However, acceleration response in ravine areas shows unusual amplification under input signal frequencies over 4 Hz. Besides, the frequency of input ground motion certainly affects the seismic site amplification. Specifically, in this study, the seismic response peaks when the input frequency is in the range of 0.4–0.8 Hz, which corresponds to the resonance frequency of the numerical model. In terms of frequency, site amplification showed a correlation between actual recordings and artificial signal inputs, but lower intensities are observed when actual records are input. Therefore, the engineering risk will be underestimated when the topographic irregularity and frequency characteristic of input ground motion are inappropriately considered. The findings of this study provide a new approach to investigate the actual 3D site amplification effects and shed new insight on regional seismic risk analysis.",
keywords = "Frequency, Ground motion, Seismic response, Site amplification, Topographic irregularity",
author = "Chen, {Zhe Xing} and Guan Chen and Yong Liu",
note = "Funding Information: This research is supported by the National Natural Science Foundation of China (Grant No. U22A20596 ) and the Natural Science Foundation Innovation Group Project of Hubei Province, China (Grant No. 2023AFA017 ). Guan Chen would like to thank the financial support of Sino-German (CSC-DAAD) Postdoc Scholarship Program . ",
year = "2024",
month = apr,
day = "1",
doi = "10.1016/j.engstruct.2024.117667",
language = "English",
volume = "304",
journal = "Engineering structures",
issn = "0141-0296",
publisher = "Elsevier BV",
}