基于地脉动单点谱比的场地特征参数测定方法适用性研究

PDF(1242 KB)

振动与冲击 ›› 2020, Vol. 39 ›› Issue (11) : 138-145.

论文

师黎静1，陈盛扬1.2

作者信息 +

The applicability of site characteristic parameters measurement based on micro-tremor’s H/V spectra

SHI Lijing1 ,CHEN Shengyang1.2

Author information +

文章历史 +

摘要

通过克拉玛依、浙江46个场地的地脉动单点三分向记录和两次地震的强震记录，对比了戈壁荒漠地区地脉动与地震动的H/V谱比，分析了地脉动H/V谱比卓越频率与覆盖层厚度、不同深度等效剪切波速以及特征周期之间的相关性，研究了基于地脉动单点谱比的场地特征参数测定方法在戈壁荒漠等覆盖层较薄以及东部沿海等覆盖层较厚地区的适用性，对该方法的高频、低频部分进行修正，扩展了适用频带范围。结果表明，在戈壁砂砾地区，地震动与地脉动H/V谱比的卓越频率具有很高的一致性；基于地脉动单点谱比的场地特征参数测定方法在计算场地覆盖层厚度、覆盖层等效周期时，对于东部沿海等深厚覆盖层场地会低估，对于戈壁荒漠等浅覆盖层场地会高估；对该方法修正后，适用频带范围扩展到了0.58~12.5Hz，计算的场地覆盖层厚度、覆盖层等效周期与实测值的平均相对误差提高到了22%和27%；在0.58~12.5Hz频带，场地Vs20、Vs30、Ts20、Ts30、Ts与地脉动卓越频率也体现出了明显的相关性，Vs30，Ts30与地脉动卓越频率的相关性要大于Vs20，Ts20。

Abstract

Combine the 46 microtremor single 3-components records of Karamay and Zhejiang with records of two earthquakes, the H/V spectral ratio of microtremor and earthquake motion in the desert region are compared, the correlation between the predominant frequency of microtremor and the equivalent shear wave velocity at different depth of overburden and the characteristic period are analyzed, and studies the applicability of the method to determine the site characteristic parameters based on the single point spectral ratio of microtremor in areas with thinner overburden in desert and thicker overburden in eastern coastal areas. The results show that in the desert region, the predominant frequency of H/V spectral curve of ground motion and microtremor has high consistency, when use the method to determine the site characteristic parameters based on the single point spectral ratio of microtremor to calculate the thickness of sediments and site period, deep overburden sites such as the eastern coast will be underestimated and shallow overburden sites such as the desert will be overestimated. The method was modified with the results of 46 microtremor tests, and the fitting relationship between the predominant frequency and the site characteristic parameters with the interval distribution of 0.58~ 12.5Hz in frequency domain was obtained. In this range, Vs20, Vs30, Ts20, Ts30 has a significant correlation with predominant frequency of microtremor, the correlation between Vs30, Ts30 and the predominant frequency of microtremor is greater than Vs20, Ts20.

关键词

地脉动 / 卓越频率 / 覆盖层厚度 / 等效剪切波速 / 特征周期

Key words

Microtremor

/ Predominant frequency / Thickness of sediments / Equivalent Shear wave velocity / site period

引用本文

EndNote

Ris (Procite)

Bibtex

导出引用

师黎静1，陈盛扬1.2. 基于地脉动单点谱比的场地特征参数测定方法适用性研究[J]. 振动与冲击, 2020, 39(11): 138-145

SHI Lijing1,CHEN Shengyang1.2. The applicability of site characteristic parameters measurement based on micro-tremor’s H/V spectra[J]. Journal of Vibration and Shock, 2020, 39(11): 138-145

参考文献

[1] 薄景山, 李秀领, 李山有. 场地条件对地震动影响研究的若干进展[J]. 世界地震工程, 2003, 19(2):11-15.
BO Jing-shan , LI Xiu-ling , LI Shan-you. Some progress of study on the effect of site conditions on ground motion[J]. World Earthquake Engineering, 2003, 19(2):11-15.
[2] Seht I V, Wohlenberg J. Microtremor Measurements Used to Map Thickness of Soft Sediments[J]. Bulletin of the Seismological Society of America, 1999, 89(1):250-259.
[3] Parolai S. New Relationships between Vs, Thickness of Sediments, and Resonance Frequency Calculated by the H/V Ratio of Seismic Noise for the Cologne Area (Germany)[J]. Bulletin of the Seismological Society of America, 2002, 92(6):2521-2527.
[4] Brown C J, Voytek E B, Lane J W, et al. Mapping bedrock surface contours using the horizontal -to-vertical spectral ratio (HVSR) method near the Middle Quarter area, Woodbury, Connecticu[J]. Center for Integrated Data Analytics Wisconsin Science Center, 2013.
[5] 曾立峰. 地脉动在黄土地区厚覆盖层探测中的应用研究[D]. 中国地震局兰州地震研究所, 2012.
Zeng Li-feng, Application of microtremors to estimate sediment thickness in loess region, Lanzhou institute of seismology[D].China Earthquake administration，2012
[6] 陈棋福, 刘澜波, 王伟君,等. 利用地脉动探测北京城区的地震动场地响应[J]. 科学通报, 2008,(18):2229-2235.
CHEN Qi-fu, LIU Lan-bo,WANG Wei-qun,et al.Site effects on earthquake ground motion based on microtremor measurements for metropolitan Beijing[J]. Chinese Science Bulletin, 2008,(18):2229-2235.
[7] 刘宇实，师黎静. 基于地脉动谱比法的场地特征参数快速测定[J]. 振动与冲击, 2018, 37(13): 235-242.
LIU Yu-shi, SHI Li-jing. Site characteristic parameters quick measurement based on micro-tremor’s H/V spectra[J]. Journal of vibration and shock, 2018, 37(13): 235-242.
[8] 石玉成. 西北地区戈壁砂砾石场地的地脉动特征[J].华南地震, 1996, 16(2): 46-52.
SHI yu-cheng. Characteristics of microtremor of sandy gravel site in Gobi desert, Northwest of china[J]. South China Journal of Seismology, 1996, 16(2): 46-52.
[9] 林建生, 王源毅. 泉州市地面脉动特征[J]. 地震工程学报, 1993(3):76-80.
Lin jian-sheng ,WANG yuan-yi. Observation and analysis of the earth microtremor of Quanzhou city[J]. China Earthguake Engineering Journal, 1993(3):76-80.
[10] Nakamura Y. A Method for Dynamic Characteristics Estimation of Subsurface Using Microtremor on Ground Surface, QR of RTRI, 30(1), 25-33[J]. Quarterly Report of Rtri, 1989, 30(1).
[11] Nakamura. A modified estimation method for amplification factor of ground and structures using the H/V spectral ratio[EB/OL]. http://www.sdr.co.jp，Mar. 2012.
[12] 彭艳菊, 吕悦军, 黄雅虹, 等. 工程地震中的场地分类方法及适用性评述[J]. 地震地质, 2009, 31(2):349-362.
PENG Yan-ju, LU Yue-jun, HUANG Ya-hong, et al. A review on site classification method and its applicability in earthquake engineering [J]. Seismology and Geology, 2009, 31(2):349-362.