河口盆地非线性地震效应及设计地震动参数
详细信息 本馆镜像全文    |  推荐本文 | | 获取馆网全文
摘要
针对基岩明显起伏、土层非均匀分布的典型河口盆地场地,考虑土体非线性特征,采用黏弹性人工边界模拟无限域对地震波动的影响,建立大尺度精细化二维有限元模型,分析了盆地地表地震动幅值、频谱、持时、传递函数特征,探讨了基岩起伏土层的地震动聚集效应及盆地边缘效应。结果表明:(1)盆地近地表土层表现出不同程度的地震动放大效应,且随土层深度增加呈非单调递减特征,基岩突变处地震动聚集效应明显,盆地两侧产生较为显著的边缘效应;场地中、长周期地震动的放大作用显著;(2)多遇地震、偶遇地震和罕遇地震水平时,场地卓越周期依次介于0.35~0.65 s、0.40~0.75 s和0.50~1.05 s之间;给出了盆地地表PGA(地表峰值加速度)、卓越周期均值等值线图及地表加速度反应谱放大因子建议值,地表设计地震动参数amax(地震影响系数)与Tg(特征周期)明显大于现行《建筑抗震设计规范》取值;(3)盆地特殊位置地表地震动持时得到不同幅度增长,且与输入地震动特性相关;(4)该盆地对0.5~2.0 Hz频段基岩地震动的放大效应比较显著,对小于0.2 Hz或大于2.5 Hz的基岩地震动,该盆地地震动放大效应不明显;(5)福州城区及其邻近区域地震动放大效应普遍较大。大尺度二维非线性分析一定程度上能合理反映微地形起伏、土层分布及土体非线性对地震波传播过程的影响。
Based on the explicit FE method and parallel computing cluster platform of ABAQUS,a large-scale refined two-dimensional(2D) nonlinear FE model is developed in the time domain with considering the heterogeneity of ground soils,for a typical site on the estuarine basin with undulating bedrock and nonuniformly distributed soil layers.The artificial viscoelastic boundary condition is proposed for simulating the semi-infinite field,the main characteristics of basin surface ground motion are analyzed,including the motion amplitude,spectrum,duration and transfer functions,and the accumulation effect of ground motion and edge effect of basin are investigated.The results show that:(1) The amplification effect at different observation points on the basin ground surface is observed;and the peak ground acceleration(PGA)of basin ground surface displays a non-monotonic decrease with soil depth;the prominent accumulation effect is found to be at particular positions where the bedrock surface sharply undulates,and the pronounced edge effect is found to be on both sides of basin;the moderate and long-period ground motions of the basin are significantly amplified compared to the short-period motions.(2) For the earthquakes with high,moderate and low occurrence probabilities,the predominant periods of the basin are 0.35-0.65 s,0.40-0.75 s and 0.50-1.05 s,respectively;the mean value contours of the peak ground acceleration and site predominant periods of the basin are plotted,and the recommended values of the amplification factor of ground motion acceleration response spectra for different period intervals are given.The seismic effect coefficient amax and characteristic period Tg of the design parameters of ground motion by this paper are significantly larger than those of the Chinese code for seismic design of buildings.(3) Ground motion durations at different points of basin ground surface extend over several orders,and the duration is also closely related to the bedrock motion characteristics.(4) Amplification effect and accumulating effect of the basin ground motion are more significant for the frequency band from 0.5 Hz to 2 Hz;while for thefrequency band lower than 0.2 Hz or higher than 2.5 Hz,the ground motion amplification characteristics are insignificant.(5) Ground motion amplification effects in Fuzhou city downtown area and its adjacent areas of the basin are generally larger,compared to other areas.It is indicated that the large-scale two-dimensional nonlinear FE model can describe the influence of micro topographic relief and nonuniformly distributed basin soil layers on seismic wave propagation.
引文
[1]ASSIMAKI D,JEONG S.Ground-motion observations at Hotel Montana during the M7.0 2010 Haiti earthquake:Topography or soil amplification[J].Bulletin of the Seismological Society of America,2013,103(5):2577-2590.
    [2]CADET Hélose.Site effect assessment using Ki K-net data:Part 1.c[J].Bulletin of Earthquake Engineering,2012,10(2):421-448.
    [3]LANZO G,SILVESTRI F,COSTANZO A,et al.Site response studies and seismic microzoning in the Middle Aterno valley(L’aquila,Central Italy)[J].Bulletin of Earthquake Engineering,2011,9(5):1417-1442.
    [4]ASSIMAKI D,LEDEZMA C,GONZALO A,et al.Site effects and damage patterns,special issue on the Maule 8.8earthquake[J].Earthquake Spectra,2012,28(1):55-74.
    [5]VINCENZO Di Fiore.Seismic site amplification induced by topographic irregularity:Results of a numerical analysis on 2D synthetic models[J].Review on Engineering Geology,2010,114(3–4):109-115.
    [6]盛志强,卢育霞,石玉成,等.河谷地形的地震反应分析[J].地震工程学报,2013,35(1):126-132.SHENG Zhi-qiang,LU Yu-xia,SHI Yu-cheng,et al.Seismic response analysis of valley topography[J].China Earthquake Engineering Journal,2013,35(1):126-132.
    [7]RICHTER C F.Elementary Seismology[M].San Francisco:WH Freeman and Company,1950.
    [8]钱培风,沈蕴芬,郭载瑜,等.通海地震的某些震害与分析[J].地震研究,1984,7(3):357-363.QIAN Pei-feng,SHEN Yun-fen,GUO Zai-yu,et al.Parts of seismic hazard in the Tonghai earthquake and their analysis[J].Journal of Seismological Research,1984,7(3):357-363.
    [9]SOMERVILLE P G,GRAVES R.Conditions that give rise to usually large long period ground motions[J].The Structural Design of Tall Buildings,1993,2(3):211-232.
    [10]SINGH S K,MENA E,CASTRO R.Some aspects of source characteristics of the 19 September 1985Michoacan earthquake and ground motion amplification in and near Mexico City from strong motion data[J].Bulletin of the Seismological Society of America,1988,78(2):451-477.
    [11]FRANCISCO J,CHáVEZ-García,PIERRE-YVES Bard.Site effects in Mexico City eight years after the September 1985 Michoacan earthquakes[J].Soil Dynamics and Earthquake Engineering,1994,13(4):229-247.
    [12]CAMPILLO M,GARIEL J C,AKI K,et al.Destructive strong ground motion in Mexico city:Source,path,and site effects during great 1985 Michoacán earthquake[J].Bulletin of the Seismological Society of America,1989,79(6):1718-1735.
    [13]STEWART J P,CHIOU S J,Bray J D,et al.Ground motion evaluation procedures for performance-based design[R].Berkeley:College of Engineering,University of California,2001.
    [14]BARD P Y,CAMPILO M,CHAVEZ-GARCIA F J,et al.The Mexico earthquake of September 19,1985—A theoretical investigation of large and small-scale amplification effects in the Mexico City valley[J].Earthquake Spectra,1988,4(3):609-633.
    [15]SEMBLAT J F,DUVALB A M,DANGLA P.Numerical analysis of seismic wave amplification in Nice(France)and comparisons with experiments[J].Soil Dynamics and Earthquake Engineering,2000,19(5):347-362.
    [16]SEMBLAT J F,DANGLA P,KHAM M,et al.Seismic site effects for shallow and deep alluvial basins:in-depth motion and focusing effect[J].Soil Dynamics and Earthquake Engineering,2002,22(9):849-854.
    [17]CHáVEZ-GARCíA F J,RAPTAKIS D,MAKRAB K,et al.Site effects at Euroseistest-II.Results from 2D numerical modeling and comparison with observations[J].Soil Dynamics and Earthquake Engineering,2000,19(1):23-39.
    [18]MAKRAA K,CHáVEZ-GARCíA F J,RAPTAKIS D,et al.Parametric analysis of the seismic response of a 2D sedimentary valley:Implications for code implementations of complex site effects[J].Soil Dynamics and Earthquake Engineering,2005,25(4):303-315.
    [19]MOCZO P.Finite-difference technique for SH waves in2-D media using irregular grids:Application to the seismic response problem[J].Geophysical Journal International,1989,99(2):321-329.
    [20]MOCZO P,BARD P-Y.Wave diffraction,amplification and differential motion near strong lateral discontinuities[J].Bulletin of the Seismological Society of America,1993,83(1):85-106.
    [21]MOCZO P,LABáK P,KRISTEK J,et al.Amplification and differential motion due to an antiplane 2D resonance in the sediment valleys embedded in a layer over the half-space[J].Bulletin of the Seismological Society of America,1996,86(5):1434-1446.
    [22]SUN Chang-guk,CHUNG Choong-ki.Assessment of site effects of a shallow and wide basin using geotechnical information-based spatial characterization[J].Soil Dynamics and Earthquake Engineering,2008,28(12):1028-1044.
    [23]郑国明.影响福州城市地下空间开发的地质因素分析[J].地下空间与工程学报,2013,9(1):13-17.ZHENG Guo-ming.Analysis of geological factors of exploiting underground space resources in Fuzhou city[J].Chinese Journal of Underground Space and Engineering.2013,9(1):13-17.
    [24]郑荣章,陈桂华,徐锡伟,等.福州盆地埋藏晚第四纪沉积地层划分[J].地震地质,2005,27(4):556-562.ZHENG Rong-zhang,CHEN Gui-hua,XU Xi-wei,et al.Sedimentary strata division of buried late quaternary of Fuzhou Basin[J]Seismology and Geology,2005,27(4):556-562.
    [25]中国人民共和国住房和城乡建设部.GB50011-2010建筑抗震设计规范[S].北京:中国建筑工业出版社,2010.
    [26]MARTIN P P,SEED H B.One dimensional dynamic ground response analysis[J].Journal of Geotechnical Engineering,ASCE,1982,108(7):935-952.
    [27]陈国兴,庄海洋.基于Davidenkov骨架曲线的土体动力本构关系及其参数研究[J].岩土工程学报,2005,27(8):860-864.CHEN Guo-xing,ZHUANG Hai-yang.Developed nonlinear dynamic constitutive relations of soils based on Davidenkov skeleton curve[J].Chinese Journal of Geotechnical Engineering,2005,27(8):860-864.
    [28]庄海洋,陈国兴,梁艳仙,等.土体动非线性黏弹性模型及其ABAQUS软件的实现[J].岩土力学,2007,28(3):436-442.ZHUANG Hai-yang,CHEN Guo-xing,LIANG Yan-xian,et al.A developed dynamic viscoelastic constitutive relations of soil and implemented by ABAQUS software[J].Rock and Soil Mechanics,2007,28(3):436-442.
    [29]刘晶波,谷音,杜义欣.一致黏弹性人工边界及黏弹性边界单元[J].岩土工程学报,2006,28(9):1070-1075.LIU Jing-bo,GU Yin,DU Yi-xin.Consistent viscous-spring artificial boundaries and viscous-spring boundary elements[J].Chinese Journal of Geotechnical Engineering,2006,28(9):1070-1075.
    [30]陈国兴,陈磊,景立平,等.地铁地下结构抗震分析并行计算显式与隐式算法比较[J].铁道学报,2011,33(11):112-117.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[J].Journal of the China Railway Society,2011,33(11):112-117.
    [31]JIN Dan-dan,CHEN Guo-xing,DONG Fei-fan.Large-scale two-dimensional nonlinear analysis on seismic effect of Fuzhou Basin[J].Applied Mechanics and Materials,2011,90(1):1426-1433.
    [32]金丹丹,陈国兴.福州盆地地震效应特征的一、二维模型对比研究[J].土木工程学报,2012,45(S1):48-53.JIN Dan-dan,CHEN Guo-xing.Large-scale two-dimensional nonlinear FE analysis vs.one-dimensional equivalent linearization analysis on seismic effect of Fuzhou Basin[J].China Civil Engineering Journal,2012,45(S1):48-53.
    [33]中国地震局.GB 18306中国地震动参数区划图(2012报批稿)[S].北京:[s.n.],2012.

版权所有:© 2023 中国地质图书馆 中国地质调查局地学文献中心