地震研究

以强地面运动加速度记录为基础,研究了竖向与水平向加速度峰值比值(V/H)的统计分布特征。结果表明,V/H服从对数正态分布。对记录按震级、震中距、场地条件和震源机制进行分类统计,研究了这些因素对V/H的影响。统计分析结果显示,V/H与震级的关系不明显; V/H随距离的增大而减小,在软土场地上尤为明显; V/H与场地条件有很大关系,在近场(R≤60 km)土层场地要高于基岩场地,而在远场则相反; 震源机制对V/H有较大影响,特别是在近场。

In this paper,the statistic analysis of peak ratios in vertical and horizontal acceleration(V/H)is done by using strong ground motion data.It is shown that V/H obeys the lognormal distribution.Based on the data,the effects of magnitude,epicentral distance,site conditions,and focal mechanism on V/H are analyzed.The results show that the effect of magnitude is inconspicuous,and V/H is reduced as the epicentral distance is increased,especially on soft soil site.In the near-field(R≤60 km),V/H on soil site is bigger than it on rock site,and it is opposite in the far-field.In addition,the focal mechanism affects to V/H greatly,especially in the near-field.

引言
1 V/H总体分布函数
2 距离和场地条件对V/H的影响
3 震源特性对V/H的影响
4 结论

图1 地震记录的震级—震中距分布<br/>Fig.1 Magnitude-distance distribution of strong ground motion data

图1 地震记录的震级—震中距分布
Fig.1 Magnitude-distance distribution of strong ground motion data

图2 V/H直方图与理论分布图<br/>Fig.2 Histogram and theoretic distribution of V/H

图2 V/H直方图与理论分布图
Fig.2 Histogram and theoretic distribution of V/H

表1 V/H概率分布检验表<br/>Tab.1 Probability distribution test of V/H

表1 V/H概率分布检验表
Tab.1 Probability distribution test of V/H

表2 不同超越概率水平对应的V/H值<br/>Tab.2 V/H of different exceeding probability

表2 不同超越概率水平对应的V/H值
Tab.2 V/H of different exceeding probability

图3 不同场地上V/H随距离的变化<br/>Fig.3 Relationship between V/H and distance on different sites

图3 不同场地上V/H随距离的变化
Fig.3 Relationship between V/H and distance on different sites

图4 不同距离内V/H随震级的变化<br/>Fig.4 Relationship between V/H and magnitude in different distances

图4 不同距离内V/H随震级的变化
Fig.4 Relationship between V/H and magnitude in different distances

表3 按震源机制分类的数据分布情况(单位:组)<br/>Tab.3 Distribution of the data classified by focal mechanisms(unit:group)

表3 按震源机制分类的数据分布情况(单位:组)
Tab.3 Distribution of the data classified by focal mechanisms(unit:group)

图5 V/H与场地条件、震源机制和距离的关系(a)基岩;(b)硬土;(c)软土<br/>Fig.5 Relationship between V/H,focal mechanism and distance on different sites (a)rock;(b)stiff soil;(c)soft soil

图5 V/H与场地条件、震源机制和距离的关系(a)基岩;(b)硬土;(c)软土
Fig.5 Relationship between V/H,focal mechanism and distance on different sites (a)rock;(b)stiff soil;(c)soft soil

董娣,桑向国,刘锐,等.2008.震源机制对近场地震动反应谱的影响[J].西北地震学报,30(1):6-10.
董娣,周锡元,闫维明,等.2006.地震动不确定性及其影响因素的初步分析[J].地震研究,29(2):167-175.
郭明珠,毛志清,魏秀丽,等.2002.伽师强震群地震动特点与震源机制关系的研究[J].地震工程与工程振动,22(1):28-31.
贺秋梅,闫维明,董娣,等.2006.震源机制和场地条件对近场强震地面运动特性的影响[J].地震研究,29(3):256-263.
李新乐,朱晞.2004.考虑场地和震源机制的近断层地震动衰减特性的研究[J].工程地质学报,12(2):141-147.
俞言祥,胡聿贤,潘华.2005.地震震源机制对长周期地震动的影响研究[J].岩石力学与工程学报,24(17):3 113-3 118.
周锡元,徐平,王国权,等.2006.1999年台湾集集地震近断层竖向与水平反应谱比值的研究[J].地震地质,28(3):325-335.
周正华,周雍年,卢滔,等.2003.竖向地震动特征研究[J].地震工程与工程振动,23(3):25-29.
周正华,周雍年,赵刚.2002.强震近场加速度峰值比和反应谱统计分析[J].地震工程与工程振动,22(3):15-18.
Bozorgnia Y,Niazi M,Kenneth W Campbell.1995.Characteristics of Free-Field Vertical Ground Motion during the Northridge Earthquake[J].Earthquake spectra,11(4):515-525.
Niazi M,Bozorgnia Y.1991.Behavior of near source peak vertical and horizontal ground motion over SMART-1 array,Taiwan[J].BSSA,81(3):715-732.
Ohsaki C S.1980.Analyses of seismic ground motion parameters including vertical components[J].Proc 7WCEE,269-276.

备注

引言

1 V/H总体分布函数

2 距离和场地条件对V/H的影响

3 震源特性对V/H的影响

4 结论

期刊信息