Two-dimensional nonlinear seismic response analysis for seabed site effect assessment in Jintang Strait

被引：0
|
作者：
Chen G.-X. [1 ,2 ]
Yue W.-Z. [1 ,2 ]
Ruan B. [3 ]
Wang Y.-Z. [1 ,2 ]
机构：
[1] Institute of Geotechnical Engineering, Nanjing Tech University, Nanjing
[2] Civil Engineering and Earthquake Disaster Prevention Center of Jiangsu Province, Nanjing
[3] Huazhong University of Science and Technology, Wuhan
来源：
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | 2021年 / 43卷 / 11期
关键词：
Seabed deep deposit; Site effect; Site response characteristic; Two-dimensional nonlinear analysis; Vertical motion;
D O I：
10.11779/CJGE202111002
中图分类号：
学科分类号：
摘要：
Ensuring the safety of coastal and offshore projects subjected to strong earthquakes is a major engineering challenge. A two-dimensional nonuniform gridding and fine finite element model for the seabed cross-section site in Jintang Strait is established using the geological and geotechnical exploration data. According to the regional tectonic setting and historical seismicity around the undersea tunnel site, the downhole array bedrock records during two strong earthquakes are selected as the input bedrock motions, the spatial inhomogeneous variation, nonlinear and hysteretic behaviors of the seabed soil are considered, and the site responses of the seabed deep deposits under various earthquake levels are simulated using the parallel method. The significant amplification and filtering effects of seismic propagation for the low-frequency components below 1 Hz and the high-frequency components higher than 10 Hz of the bedrock motions are observed in the site responses. With the increase of bedrock motion levels, the values of acceleration transfer function of the seabed site decrease, and the predominant frequencies of the seabed site response tend to be lower. The peak acceleration amplification factors of the seabed surface are obviously lower than those of the general land sites. The 5% damping spectral acceleration spectra and the cumulative absolute velocity at the seabed surface are significantly affected by the bedrock motion characteristics and seabed local site conditions. The coupled horizontal and vertical bedrock motions exhibit a substantial negative influence on the design ground motion parameters of the seabed site, compared to those in the cases of only the horizontal bedrock shaking. The determination of the design ground motion parameters of the seabed site based on the current seismic code may be unsafe. © 2021, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.
引用
收藏
页码：1967 / 1975
页数：8
相关论文
共 19 条
  • [1] DHAKAL Y P, AOI S, KUNUGI T, Et al., Assessment of nonlinear site response at ocean bottom seismograph sites based on S-wave horizontal-to-vertical spectral ratios: a study at the Sagami Bay area K-NET sites in Japan, Earth, Planets and Space, 69, 1, (2017)
  • [2] HU J J, TAN J Y, ZHAO J X., New GMPEs for the Sagami bay region in Japan for moderate magnitude events with emphasis on differences on site amplifications at the seafloor and land seismic stations of K-NET, Bulletin of the Seismological Society of America, 110, 5, pp. 2577-2597, (2020)
  • [3] TAN J Y, HU J J., A prediction model for vertical-to-horizontal spectral ratios of ground motions on the seafloor for moderate magnitude events for the Sagami Bay region in Japan, Journal of Seismology, 25, 1, pp. 181-199, (2021)
  • [4] ZHANG Q, ZHENG X Y., Offshore earthquake ground motions: Distinct features and influence on the seismic design of marine structures, Marine Structures, 65, pp. 291-307, (2019)
  • [5] CHEN Guo-xing, CHEN Lei, JING Li-ping, Et al., Comparison of implicit and explicit finite element methods with parallel computing for seismic response analysis of metro underground structures, Journal of the China Railway Society, 33, 11, pp. 111-118, (2011)
  • [6] CHEN G X, JIN D D, ZHU J, Et al., Nonlinear analysis on seismic site response of Fuzhou basin, China, Bulletin of the Seismological Society of America, 105, 2A, pp. 928-949, (2015)
  • [7] RUAN B, ZHAO K, WANG S Y, Et al., Numerical modeling of seismic site effects in a shallow estuarine bay (Suai Bay, Shantou, China), Engineering Geology, 260, (2019)
  • [8] TRIFUNAC M D., Nonlinear soil response as a natural passive isolation mechanism. Paper II. The 1933, Long Beach, California earthquake, Soil Dynamics and Earthquake Engineering, 23, 7, pp. 549-562, (2003)
  • [9] CHEN Guo-xing, LI Lei, DING Jie-fa, Et al., Nonlinear seismic response characteristics of extremely deep deposit site with volcanic hard rock interlayers, Rock and Soil Mechanics, 41, 9, pp. 3056-3065, (2020)
  • [10] CHEN G X, RUAN B, ZHAO K, Et al., Nonlinear response characteristics of undersea shield tunnel subjected to strong earthquake motions, Journal of Earthquake Engineering, 24, 3, pp. 351-380, (2020)
12