Site effect of unconsolidated soil hill based on seismic array records
-
摘要: 选取2008年5月25日至8月7日期间由甘肃省文县上城山地形效应台阵获取的12次汶川地震余震事件(MS≥4.0)，在分析其地震动基本参数的基础上，采用参考场地谱比(RSSR)法和水平-竖向谱比(HVSR)法，研究了不同地震作用下上城山地形台阵的场地效应.分析结果显示：随着高程和覆盖层的增加，记录台站地震动的PGA呈增大趋势，地震频谱形状由宽变窄；上城山台阵记录到的地震波在地形基阶频段(2—4 Hz)和浅部土层频段(7—9 Hz)的幅值明显放大，RSSR曲线显示山顶NS向的土层频段谱比大于山体地形频段谱比；由于土层山体竖向地震动在中高频段放大，使得HVSR方法谱比结果在中高频段较RSSR方法所得结果明显偏低，而在山体基阶频段附近两种方法的谱比值接近.松散土层山体的台阵记录特征体现了地形和土层对地震动的联合作用，揭示了强震区起伏地形场地震害加重及地震滑坡集中发生的原因所在.Abstract: Following the 2008 MS8.0 Wenchuan earthquake, a topographical array including four digital seismograph stations was installed along Shangcheng hill, Wenxian, Gansu Province, which is a piedmont diluvial terrace about 50-m high and made up of Quaternary silty clay and gravelly soil with thin layer of coarse sand. One of the stations was installed at a rock cave in northeastern Shangcheng hill, and the other three stations were respectively installed at the foot of the hill, hill slope and hill top. From May 25 to August 7, 2008, a series of aftershocks of Wenchuan MS8.0 earthquake occurred, but only twelve events (MS≥4.0) were recorded at three of the four stations at least. In this study, seismic response of each station is evaluated as a function of frequency by reference site spectral ratio (RSSR) method and single-station horizontal to vertical spectral ratio (HVSR) based on all shear waves from the twelve earthquake events. The analyses lead to the conclusions that: ① with the elevation climbing and soil thickening, the PGAs of the twelve events increase and the broadband seismic spectra gradually narrow to the characteristic frequency band; ② dynamic amplification of Shangcheng hill occurs in both topographic characteristic frequency band (2--4 Hz) and shallow stratigraphic fundamental frequency band (7--9 Hz)in horizontal direction, while amplification caused by the soil stratigraphy near surface is comparatively more obvious than that by the topography in NS at hill top; ③ in medium-high frequency band, the spectral ratio from HVSR method is much lower than that from RSSR method due to the amplitude of seismic waves in vertical direction. The characteristics of seismic array records of the unconsolidated soil hill give expression to the combined effect of topography and soil stratigraphy, and reveal the reasons for the aggravation of structural damage and the concentration of seismic landslide on topographic site in strong ground motion zone.
-
中国地震局强震台网中心和甘肃省地震局监测中心提供了地震数据，审稿专家对本文评阅并提出了建议，作者在此一并表示感谢！
-
![]()
图 1 本文所用地震事件分布(a)和文县地震台阵位置(b)
Figure 1. Distribution of earthquake events used in this study (a) and location of Wenxian seismic array (b)
![]()
图 2 文县地震台阵的地质资料
(a) T2台站附近的钻孔剖面；(b) T3和T4台站附近上城山出露的地层剖面
Figure 2. Geological data of Wenxian seismic array
(a) Drilling geological section near the station T2; (b) Outcrop of Shangcheng hill near the stations T3 and T4
![]()
图 3 12次地震事件的地震动峰值加速度随地形相对高程的变化
Figure 3. Variation of PGAs with the relative elevation increasing for twelve earthquake events
![]()
图 4 文县台阵记录到的5次地震的傅里叶谱对比
Figure 4. Fourier spectra observed on Wenxian array in five earthquake events
![]()
图 5 5次地震事件中水平向参考场地谱比RSSR
Figure 5. Horizontal reference site spectral ratios (RSSRs) in five earthquake events
![]()
图 6 5次地震事件的竖向参考场地谱比RSSR
Figure 6. Vertical reference site spectral ratios (RSSRs) in five earthquake events
![]()
图 7 文县台阵12次地震事件的水平-竖向谱比HVSR
Figure 7. Horizontal to vertical spectral ratios (HVSRs) of Wenxian array in twelve earthquake events
![]()
图 8 利用参考场地谱比(RSSR)和水平-竖向谱比(HVSR)两种方法得到的场地效应对比
Figure 8. Comparison of site effects calculated by RSSR (solid lines) and HVSR (dotted lines) methods
表 1 本文所用12次地震事件的基本参数
Table 1 Parameters of the twelve earthquake events used in this study
地震事件 MS 震中距/km 文县地形台阵记录PGA/(cm·s-2) 发震日期 T1台站 T2台站 T3台站 T4台站 年-月-日 EW NS UD EW NS UD EW NS UD EW NS UD E1 2008-05-25 6.4 87 19.4 22.7 16.1 65.6 111.5 103.2 80.5 106.5 94.4 - - - E2 2008-05-27 5.7 88 11.1 14.2 10.4 51.3 61.6 44.6 54.2 67.6 48.9 46.3 105.6 51.7 E3 2008-06-05 4.8 78 5.9 6.5 3.8 21.6 25.7 27.1 22.7 22.6 23.8 18.8 29.5 26.4 E4 2008-06-07 4.2 83 - - - 5.3 5.4 6.1 6.3 8.8 6.2 8.1 14.7 7.2 E5 2008-06-08 4.7 63 - - - 20.6 16.4 14.5 18.9 17.6 16.7 15.4 24.8 18.0 E6 2008-06-17 4.3 87 - - - 5.7 6.6 5.4 6.8 8.2 9.7 7.6 13.0 7.9 E7 2008-06-19 4.4 78 - - - 9.8 10.2 7.3 12.7 14.2 11.0 12.7 24.5 11.6 E8 2008-06-22 4.2 84 - - - 9.0 6.7 7.8 8.3 7.8 8.8 13.6 12.1 6.0 E9 2008-06-23 4.0 72 - - - 6.0 4.8 6.6 5.8 5.6 6.3 6.9 8.2 5.3 E10 2008-06-28 4.5 136 - - - 10.1 5.7 9.4 13.4 10.2 9.5 11.0 10.9 10.1 E11 2008-08-01 6.2 104 7.6 8.0 5.8 37.1 28.1 27.2 39.6 39.5 38.3 41.6 44.3 33.0 E12 2008-08-07 5.0 92 3.6 2.5 3.0 9.9 11.6 9.8 14.1 18.4 15.2 19.4 23.5 17.7 
下载: 导出CSV
表 2 文县地震台阵各台站相对于T1台站的PGA放大系数γ
Table 2 Amplification factor γ of PGA of the stations to that of T1 for the Wenxian seismic array
地震事件 γT2/T1 γT3/T1 γT4/T1 EW NS UD EW NS UD EW NS UD E1 3.4 4.9 6.4 4.1 4.7 5.9 - - - E2 4.6 4.3 4.3 4.9 4.8 4.7 4.2 7.4 5.0 E3 3.7 4.0 7.1 3.8 3.5 6.3 3.2 4.5 6.9 E11 4.9 3.5 4.7 5.2 4.9 6.6 5.5 5.5 5.7 E12 2.8 4.6 3.3 3.9 7.4 5.1 5.4 9.4 5.9
下载: 导出CSV
-
洪海春, 尤捷, 陶小三, 王恒知. 2015. 2014年云南鲁甸地震和景谷地震的震害对比研究[J].地震工程学报, 37(4): 1013-1022. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=zbdz201504018&dbname=CJFD&dbcode=CJFQ Hong H C, You J, Tao X S, Wang H Z. 2015. Comparative study of seismic damage induced by 2014 Ludian MS6.5 and Jinggu MS6.6 earthquakes in Yunnan Province[J]. China Earthquake Engineering Journal, 37(4): 1013-1022 (in Chinese). http://www.en.cnki.com.cn/Article_en/CJFDTOTAL-ZBDZ201504018.htm
华卫, 陈章立, 郑斯华. 2010.利用不同方法估算流动台站的场地响应[J].地震, 30(3): 30-44. http://www.cqvip.com/QK/92280X/201003/34624150.html Hua W, Chen Z L, Zheng S H. 2010. Estimation of site responses for temporary stations using various methods[J]. Earthquake, 30(3): 30-44 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DIZN201003004.htm
李孝波, 薄景山, 王欣, 万卫. 2017.基岩地形对地震动影响研究[J].岩土工程学报, 39(3): 460-468. http://manu31.magtech.com.cn/Jwk_ytgcxb/CN/Y2017/V39/I3/460 Li X B, Bo J S, Wang X, Wan W. 2017. Effect of bedrock terrain on seismic ground motion[J]. Chinese Journal of Geotechnical Engineering, 39(3): 460-468 (in Chinese). http://www.iitk.ac.in/nicee/wcee/article/WCEE2012_1046.pdf
李小军. 2013.地震动参数区划图场地条件影响调整[J].岩土工程学报, 35(增刊2): 21-29. http://www.oalib.com/paper/4371000 Li X J. 2013. Adjustment of seismic ground motion parameters considering site effects in seismic zonation map[J]. Chinese Journal of Geotechnical Engineering, 35(S2): 21-29 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTOTAL-YTGC2013S2005.htm
李渝生, 黄润秋. 2009. 5·12汶川大地震损毁城镇的震害效应与重建选址问题[J].岩石力学与工程学报, 28(7): 1370-1376. doi: 10.3321/j.issn:1000-6915.2009.07.010 Li Y S, Huang R Q. 2009. Earthquake damage effects of towns and reconstruction site selection in Wenchuan earthquake on May 12, 2008[J]. Chinese Journal of Rock Mechanics and Engineering, 28(7): 1370-1376 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTotal-YSLX200907012.htm
廖振鹏, 杨柏坡, 袁一凡. 1981.三维地形对地震地面运动的影响[J].地震工程与工程振动, 1(1): 56-77. http://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ201405028.htm Liao Z P, Yang B P, Yuan Y F. 1981. Effects of three-dimensional topography on earthquake ground motion[J]. Earthquake Engineering and Engineering Vibration, 1(1): 56-77 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DGGC198101006.htm
刘甲美, 高孟潭, 陈鲲. 2015.地形效应影响下地震动参数与斜坡稳定性的相关性研究[J].地震学报, 37(5): 865-874. doi: 10.11939/jass.2015.05.014 Liu J M, Gao M T, Chen K. 2015. On the correlation of ground motion parameters with slope stability incorporating topographic effects[J]. Acta Seismologica Sinica, 37(5): 865-874 (in Chinese). http://www.dzxb.org/Magazine/Show?id=29131
卢育霞, 石玉成, 万秀红, 马林伟, 卢芳琴. 2014.近地表速度结构对场地强地震动特征的影响[J].地震工程学报, 36(4): 813-819. http://www.cnki.com.cn/Article/CJFDTOTAL-ZBDZ201603006.htm Lu Y X, Shi Y C, Wan X H, Ma L W, Lu F Q. 2014. Influence of near-surface velocity structure on site characteristics of strong ground motion[J]. China Earthquake Engineering Journal, 36(4): 813-819 (in Chinese). http://www.en.cnki.com.cn/Article_en/CJFDTOTAL-ZBDZ201404008.htm
荣棉水, 李小军, 王振明, 吕悦军. 2016. HVSR方法用于地震作用下场地效应分析的适用性研究[J].地球物理学报, 59(8): 2878-2891. doi: 10.6038/cjg20160814 Rong M S, Li X J, Wang Z M, Lü Y J. 2016. Applicability of HVSR in analysis of site-effects caused by earthquakes[J]. Chinese Journal of Geophysics, 59(8): 2878-2891 (in Chinese). http://www.iitk.ac.in/nicee/wcee/article/WCEE2012_3537.pdf
石玉成, 卢育霞. 2009.汶川8.0级地震甘肃灾区震害特点及恢复重建对策[J].西北地震学报, 31(1): 1-7. http://edu.wanfangdata.com.cn/Periodical/Detail/zhx201302007 Shi Y C, Lu Y X. 2009. The damage features of Wenchuan 8.0 earthquake in Gansu disaster area and countermeasures of reconstruction[J]. Northwest Seismological Journal, 31(1): 1-7 (in Chinese). http://d.wanfangdata.com.cn/Periodical_xbdzxb200901001.aspx
唐晖, 李小军, 李亚琦. 2012.自贡西山公园山脊地形的场地效应分析[J].振动与冲击, 31(8): 74-79. http://www.cqvip.com/QK/88497X/201104/40595209.html Tang H, Li X J, Li Y Q. 2012. Site effect of topograghy on ground motions of Xishan park of Zigong city[J]. Journal of Vibration and Shock, 31(8): 74-79 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTOTAL-ZDCJ201208016.htm
王海云, 谢礼立. 2010.自贡市西山公园地形对地震动的影响[J].地球物理学报, 53(7): 1631-1638. http://www.oalib.com/paper/4869548 Wang H Y, Xie L L. 2010. Effects of topography on ground motion in the Xishan park, Zigong city[J]. Chinese Journal of Geophysics, 53(7): 1631-1638 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTotal-DQWX201007015.htm
王海云. 2014.土层场地的放大作用随深度的变化规律研究:以金银岛岩土台阵为例[J].地球物理学报, 57(5): 1498-1509. doi: 10.6038/cjg20140514 Wang H Y. 2014. Study on variation of soil site amplification with depth: A case at Treasure Island geotechnical array, San Francisco Bay[J]. Chinese Journal of Geophysics, 57(5): 1498-1509 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTotal-DQWX201405014.htm
王兰民, 吴志坚. 2013.岷县漳县6.6级地震震害特征及其启示[J].地震工程学报, 35(3): 401-412. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=zbdz201303002&dbname=CJFD&dbcode=CJFQ Wang L M, Wu Z J. 2013. Earthquake damage characteristics of the Minxian-Zhangxian MS6.6 earthquake and its lessons[J]. China Earthquake Engineering Journal, 35(3): 401-412 (in Chinese). http://en.cnki.com.cn/Article_en/CJFDTotal-ZBDZ201303002.htm
王伟, 刘必灯, 刘欣, 杨明亮, 周正华. 2015.基于汶川MS8.0地震强震动记录的山体地形效应分析[J].地震学报, 37(3): 452-462. http://www.dzxb.org/Magazine/Show?id=29093 Wang W, Liu B D, Liu X, Yang M L, Zhou Z H. 2015. Analysis on the hill topography effect based on the strong ground motion records of Wenchuan MS8.0 earthquake[J]. Acta Seismologica Sinica, 37(3): 452-462 (in Chinese). http://www.dzxb.org/Magazine/Show?id=29093
章文波, 谢礼立, 郭明珠. 2001.利用强震记录分析场地的地震反应[J].地震学报, 23(6): 604-614. http://www.dzxb.org/Magazine/Show?id=26991 Zhang W B, Xie L L, Guo M Z. 2001. Estimation on site-amplification from different methods using strong motion data obtained in Tangshan, China[J]. Acta Seimologica Sinica, 23(6): 604-614 (in Chinese). http://www.dzxb.org/Magazine/Show?id=26991
Borcherdt R D. 1970. Effects of local geology on ground motion near San Francisco Bay[J]. Bull Seismol Soc Am, 60(1): 29-61. https://pubs.geoscienceworld.org/bssa/article-lookup/60/1/29
Géli L, Bard P Y, Jullien B. 1988. The effect of topography on earthquake ground motion: A review and new results[J]. Bull Seismol Soc Am, 78(1): 42-63. https://pubs.geoscienceworld.org/ssa/bssa/article-abstract/78/1/42/102266/the-effect-of-topography-on-earthquake-ground?redirectedFrom=fulltext
Hartzell S, Meremonte M, Ramírez-Guzmán L, McNamara D. 2014. Ground motion in the presence of complex topography: Earthquake and ambient noise sources[J]. Bull Seismol Soc Am, 104(1): 451-466. doi: 10.1785/0120130088
Lermo J, Chávez-García F J. 1994. Are microtremors useful in site response evaluation?[J]. Bull Seismol Soc Am, 84(1): 1350-1364. https://www.mendeley.com/research-papers/microtremors-useful-site-response-evaluation/
Massa M, Lovati S, D′Alema E, Ferretti G, Bakavoli M. 2010. An experimental approach for estimating seismic amplification effects at the top of a ridge, and the implication for ground-motion predictions: The case of Narni, Central Italy[J]. Bull Seismol Soc Am, 100(6): 3020-3034. doi: 10.1785/0120090382
Moya C A, Aguirre J, Irikura K. 2000. Inversion of source parameters and site effects from strong ground motion records using genetic algorithms[J]. Bull Seismol Soc Am, 90(4): 977-992. doi: 10.1785/0119990007
Nakamura Y. 1989. A method for dynamic characteristics estimation of subsurface using microtremor on the ground surface[J]. Rep Railway Tech Res Inst Jpn, 30(1): 25-33. http://www.oalib.com/references/18986827
Paolucci R. 2002. Amplification of earthquake ground motion by steep topographic irregularities[J]. Earthq Eng Struct Dyn, 31(10): 1831-1853. doi: 10.1002/(ISSN)1096-9845
计量
- 文章访问数: 1322
- HTML全文浏览量: 566
- PDF下载量: 32
