易液化深厚覆盖层地震动放大效应台阵观测与分析

周燕国; 谭晓明; 陈捷; 裴向军; 陈云敏

doi:10.11779/CJGE201707015

易液化深厚覆盖层地震动放大效应台阵观测与分析 English Version

周燕国^{1, 2, 3},
谭晓明^{1, 2, 4},
陈捷^{1, 2},
裴向军^3, ,,
陈云敏^{1, 2}

1. 浙江大学软弱土与环境土工教育部重点实验室,浙江杭州 310058;
2. 浙江大学岩土工程研究所,浙江杭州 310058;
3. 成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都 610059;
4. 中建三局投资发展有限公司,湖北武汉 430070

基金项目: 国家自然科学基金项目（51578501）; 浙江省自然科学基金项目（LR15E080001）; “国家特支计划”青年拔尖人才项目（2013）; 国家重点基础研究发展计划（“973”计划）项目（2014CB047005）; 地质灾害防治与地质环境保护国家重点实验室开放基金项目（SKLGP2015K017）

详细信息

作者简介:
周燕国(1978- ),男,博士,副教授,博士生导师,主要从事土动力学与地震工程,岩土工程减灾,土工离心机物理模拟方面的研究和教学工作。E-mail: qzking@zju.edu.cn。

通讯作者:
裴向军，E-mail：peixj0119@tom.com

计量
- 文章访问数: 356
- HTML全文浏览量: 13
- PDF下载量: 267
出版历程
- 收稿日期: 2016-06-16
- 发布日期: 2017-07-24

Observations and analyses of site amplification effects of deep liquefiable soil deposits by geotechnical downhole array

ZHOU Yan-guo^{1, 2, 3},
TAN Xiao-ming^{1, 2, 4},
CHEN Jie^{1, 2},
PEI Xiang-jun^3, ,,
CHEN Yun-min^{1, 2}

1. MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Hangzhou 310058, China;
2. Institute of Geotechnical Engineering, Zhejiang University, Hangzhou 310058, China;
3. State Key Laboratory of Geo-Hazard Prevention and Geo-Environment Protection, Chengdu University of Technology, Chengdu 610059, China;
4. Investment Development Co., Ltd., CCTEB, Wuhan 430070, China

摘要

摘要: 基于美国加州Caltrans/CDMG的两个井下台阵加速度记录,从时域和频域分析了百米级易液化深厚覆盖层在不同地震下的地震动放大效应,揭示了地震动从基岩向覆盖层传播的4个重要特征：①加速度放大效应受土层深度影响,近地表20~30 m以内放大效应突出;②地震动三分量的放大效应具有方向性,水平向与竖向地震动放大效应差异显著;③基岩加速度呈现“小震放大、大震衰减”的规律;④加速度放大规律与频率相关,深厚覆盖层放大频带较宽。初步分析了造成上述放大效应的可能原因。在此基础上,基于平面波动假设提出了考虑层间波阻抗比放大和传播路径衰减的深厚覆盖层加速度放大效应简化函数,改进了1/4波长法的参数取值,并结合自由表面效应,对前述台阵记录的放大效应进行了估算,发现无论时域还是频域,预测结果与实际观测都较接近。本文研究成果可为深厚覆盖层液化判别和抗震设计的加速度选取提供理论依据和简化分析方法。
- 深厚覆盖层 /
- 地震动 /
- 放大效应 /
- 井下台阵 /
- 峰值加速度 /
- 反应谱 /
- 平面波
Abstract: Based on the accelerations recorded from two downhole arrays instrumented by the Caltrans/CDMG project, the site amplification effects of deep liquefiable soil deposits are analyzed in both time and frequency domains, and several important features of the wave propagation from the bedrock to the overlying soil layers are observed: (1) The depth of soil deposit affects the site amplification considerably, and large part of the amplification occurs in the near-surface zone within the depth of 20~30 m; (2) The amplification differs from one to another direction, and the difference between the horizontal and vertical shakings is significant; (3) The amplification occurs when the input bedrock motion is small, while the de-amplification effects are observed when the bedrock input motion is large enough; (4) The amplification is frequency dependent, and the deep deposits amplify the bedrock ground motion in a wide frequency band. The underlying mechanisms are preliminarily analyzed. The simplified function accounting for the impedance contrast amplification and thickness attenuation effects is proposed based on the plane wave assumptions, and the parameters are improved for the quarter wave length method. The amplification ratios are predicted for all four events in conjunction with "free-surface effect", where the predictions are found in good agreement with the observations either in time or frequency domain. The present study provides a theoretical basis and simplified method for estimating the ground motions for liquefaction evaluation and seismic design of deep liquefiable soil deposits.
- deep deposit /
- ground motion /
- site amplification /
- geotechnical downhole array /
- peak acceleration /
- response spectrum /
- plane wave

HTML全文

参考文献(36)

[1]	许强, 陈伟, 张倬元. 对我国西南地区河谷深厚覆盖层成因机理的新认识[J]. 地球科学进展, 2008, 23(5): 448-456. (XU Qiang, CHEN Wei, ZHANG Zhou-yuan. New views on forming mechanism of deep overburden on river bed in southwest of china[J]. Advance in Earth Science, 2008, 23(5): 448-456. (in Chinese))
[2]	王启国. 金沙江虎跳峡河段河床深厚覆盖层成因及工程意义[J]. 岩石力学与工程学报, 2009, 28(7): 1455-1466. (WANG Qi-guo. Causes of riverbed deep cover and engineering significance of tiger leaping gorge reach of jinsha river[J]. Chinese Journal of Rock Mechanics and Engineering, 2009, 28(7): 1455-1466. (in Chinese))
[3]	裴向军, 黄润秋.“4•20”芦山地震地质灾害特征分析[J]. 成都理工大学学报（自然科学版）,2013, 40(3): 257-262. (PEI Xiang-jun, HUANG Run-qiu. Analysis of Characteristics of geological hazards by “4·20” Lushan earthquake in Sichuan, China[J]. Journal of Chengdu University of Technology (Science & Technology Edition), 2013, 40(3): 257-262. (in Chinese))
[4]	LIU Y F, HUANG R Q. Seismic liquefaction and related damage to structures during the 2013 Lushan M w 6.6 earthquake[J]. Disaster Advances, 2013, 6(10): 55-64.
[5]	CETIN K O, SEED R B. Nonlinear shear mass participation factor ( r d ) for cyclic shear stress ratio evaluation[J]. Soil Dynamics and Earthquake Engineering, 2004, 24(2): 103-113.
[6]	韩超, 周燕国, 凌道盛, 等. 液化判别应力折减系数分布特征研究[J]. 岩石力学与工程学报, 2010, 29(9): 1833-1839. (HAN Chao, ZHOU Yan-guo, LING Dao-sheng, et al. Study of distribution features of stress reduction coefficient in liquefaction evaluation[J]. Chinese Journal of Rock Mechanics and Engineering, 2010, 29(9): 1833-1839. (in Chinese))
[7]	GAO Y F, ZHANG N, ZHANG D Y. Effects of topographic amplification induced by a U-Shaped canyon on seismic waves[J]. Bulletin of the Seismological Society of America, 2012, 102: 1748-1763.
[8]	金丹丹, 陈国兴, 董菲蕃, 多地貌单元复合场地非线性地震效应特征二维分析[J]. 岩土力学, 2014, 35(6): 1818-1825. (JIND Dan-dan, CHEN Guo-xing, DONG Fei-fan. 2D analysis of nonlinearseismic effect characteristics of muti-geomorphic compositesite[J]. Rock and Soil Mechanics, 2014, 35(6): 1818-1825. (in Chinese))
[9]	KRAMER S L. Geotechnical earthquake engineering[M]. New York: Prentice-Hall, 1996.
[10]	陈国兴, 陈继华. 软弱土层的厚度及埋深对深厚软弱场地地震效应的影响[J]. 世界地震工程, 2004, 20(3): 66-73. (CHEN Guo-xing CHEN Ji-hua. The effect of depth and thickness of soft soil layer on earthquake response for deep soft sites[J]. World Earthquake Engineering, 2004, 20(3): 66-73. (in Chinese))
[11]	庄海洋, 刘雪珠, 陈国兴. 互层土的动参数试验研究及其地震反应分析[J]. 岩土力学, 2005, 26(9): 1495-1498. (ZHUANG Hai-yang, LIU Xue-zhu, CHEN Guo-xing. A study on dynamic parameters and seismic response of interbeddedsoil[J]. Rock and Soil Mechanics, 2005, 26(9): 1495-1498. (in Chinese))
[12]	高广运, 陈青生, 何俊锋, 等. 地下水位上升对上海软土场地地震反应的影响[J]. 岩土工程学报, 2011, 33(7): 989-995. (GAO Guang-yun CHEN Qing-sheng, HE Jun-feng, et al. Effect of rise of groundwater table on seismic ground response of soft soil in Shanghai[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(7): 989-995. (in Chinese))
[13]	黄雨, 叶为民, 唐益群, 等. 上海软土场地的地震反应特征分析[J]. 地下空间与工程学报, 2005, 1(5): 773-778. (HUANG Yu, YE Wei-min, TANG Yi-qun, et al. Characteristic analysis for seismic ground response of soft soils in Shanghai[J]. Chinese Journal of Underground Space and Engineering, 2005, 1(5): 773-778. (in Chinese))
[14]	李平, 薄景山, 李孝波, 等. 安宁河河谷及邛海地区土层场地对地震动的放大作用[J]. 岩土工程学报, 2016, 38(2): 362-369. (LI Ping, BO Jing-shan, LI Xiao-bo, et al. Amplification effect of soil sites on ground motion in Anning River valley and Qionghai Lake area[J]. Chinese Journal of Geotechnical Engineering, 2016, 38(2): 362-369. (in Chinese))
[15]	WALD L A, MORI J. Evaluation of methods for estimating linear site-response amplifications in the Los Angeles region[J]. Bulletin of the Seismological Society of America, 2000, 90(6B): 32-42.
[16]	王海云. 渭河盆地中土层场地对地震动的放大作用[J].地球物理学报, 2011, 54(1): 137-150. (WANG Hai-yun. Amplication effects of soil sites on ground motion in the Weihe basin[J]. Chinses Journal of Geophysics, 2011, 54(1): 137-150. (in Chinese))
[17]	任叶飞, 温瑞智, 山中浩明, 等. 运用广义反演法研究汶川地震场地效应[J]. 土木工程学报, 2013, 46(增刊): 146-151. （REN Ye-fei, WEN Rui-zhi, HIROAKI Yamanaka, et al. Research on site effect of Wenchuan Earthquake by using generalized inversion technique[J]. China Civil Engineering Journal, 2013, 46(S0): 146-151. (in Chinese)）
[18]	迟明杰, 陈永新, 李小军. 地表岩土层对地震动特性的影响分析[J]. 国际地震动态, 2015, 37(3): 743-747. (CHEN Yong-xin, CHI Ming-jie, LI Xiao-jun. Effect of overlaying rock and soil layers on ground motion characteristics[J]. China Earthquake Engineering Journal, 2015, 37(3): 743-747. (in Chinese))
[19]	ELGAMAL A W, ZEGHAL M, PARRA E, et al. Identification and modeling of earthquake ground response: I site amplification[J]. Soil Dynamics and Earthquake Engineering, 1996, 15(8): 499-522.
[20]	GRAIZER V, CAO T, SHAKAL A, et al. Data from downhole arrays instrumented by the California Strong Motion Instrumentation Program in studies of site amplification effects[C]// Proceedings of the 6th International Conference on Seismic Zonation. Palm Springs, 2000.
[21]	YOUD T, CARTER B. Influence of soil softening and liquefaction on spectral acceleration[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2005, 131(7): 811-825.
[22]	SALVATI L, PESTANA J. Small-strain behavior of granular soils: II seismic response analyses and model evaluation[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2006, 132(8): 1082-1090.
[23]	PENZIEN J, WATABE M. Characteristics of 3-dimensional earthquake ground motions[J]. Earthquake Engineering & Structural Dynamics, 1974, 3(4): 365-373.
[24]	YANG J, SATO T. Interpretation of seismic vertical amplification observed at an array site[J]. Bulletin of the Seismological Society of America, 2000, 90(2): 275-285.
[25]	ZEGHAL M, ELGAMAL A W, TANG H T, et al. Lotung downhole array: Ⅱ evaluation of soil nonlinear properties[J]. Journal of Geotechnical Engineering, 1995, 121(4): 363-378.
[26]	王海云. 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, 2014, 57(5): 1498-1509. (WANG Hai-yun. 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))
[27]	PESTANA J, SALVATI L. Small-strain behavior of granular soils: I model for cemented and uncemented sands and gravels[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2006, 132(8): 1071-1081.
[28]	YANG J, YAN X R. Site response to multi-directional earthquake loading: a practical procedure[J]. Soil Dynamics and Earthquake Engineering, 2009, 29: 710-721.
[29]	SHEARER P M, ORCUTT J A. Surface and near-surface effects on seismic waves—theory and borehole seismometer results[J]. Bulletin of the Seismological Society of America, 1987, 77(4): 1168-1196.
[30]	BOORE D M. The uses and limitations of the square-root-impedance method for computing site amplification[J]. Bulletin of the Seismological Society of America, 2013, 103(4): 2356-2368.
[31]	ANDERSON J G, LEE Y, ZENG Y, et al. Control of strong motion by the upper 30 meters[J]. Bulletin of the Seismological Society of America, 1996, 86: 1749-1759.
[32]	姜慧. 地震动随机模拟方法中的场地效应研究[D]. 北京: 中国地震局地球物理研究所, 2005. (JIANG Hui. Study on site effects of stochastic simulation of earthquake ground motions[D]. Beiijing: Institute of Geophysics, China Earthquake Administration, 2015. (in Chinese))
[33]	曾立峰, 吴志坚, 陈拓, 等. 天水黄土地区覆盖层厚度的反演研究[J]. 岩土力学, 2012, 33(6): 1912-1916. (ZENG Li-feng, WU Zhi-jian, CHEN Tuo, et al. Inversing study of overburden thickness in loess area of Tianshui[J]. Rock and Soil Mechanic, 2012, 33(6): 1912-1916. (in Chinese))
[34]	BERESNEV I A, WEN K L. P-wave amplification by near-surface deposits at different excitation levels[J]. Bulletin of the Seismological Society of America, 1995, 85(5): 1490-1494.
[35]	IDRISS I M. An NGA empirical model for estimating the horizontal spectral values generated by shallow crustal earthquakes[J]. Earthquake Spectra, 2008, 24(1): 217-242.
[36]	李伟华, 赵成刚. 含软夹层的层状沉积河谷场地的地震动力响应分析[J]. 岩土力学, 2009, 30(1): 45-51. (LI Wei-hua, ZHAO Cheng-gang. Analysis of seismic dynamic response of layered alluvial valleys with soft interlayer[J]. Rock and Soil Mechanic, 2009, 30(1): 45-51. (in Chinese))