共查询到20条相似文献，搜索用时 15 毫秒
1.
本文以国内川滇甘陕地区263个有详细场地资料的强震台站获得的802组地震动加速度记录为基础,研究了该地区加速度峰值比的总体分布特征,分别探讨了震中距和震级对加速度峰值比的影响特征,按照水平反应谱的标定方法对竖向反应谱进行标定并对其进行了统计分析。统计分析结果显示:竖向与水平向加速度峰值比的概率分布总体服从极值Ⅱ型分布,加速度峰值比均值为0.6,加速度峰值比≤0.65的累积频率为64%;Ⅱ类场地的加速度峰值比随震中距增大而减小;大震近场的加速度峰值比基本上远高于0.65;最后本文给出了不同场地类别下竖向反应谱特征参数,并与水平向反应谱特征参数进行了比较。 相似文献
2.
WANG Heng-zhi YU Yan-xiang HE Bin PENG Xiao-bo ZHAN Xiao-yan ZHU Sheng-chu 《地震地质》2018,40(6):1349-1361
An M4.9 earthquake occurred at the junction of Gaoyou and Baoying on July 20, 2012. In this paper, 43 sets of strong motion records of the main shock are analyzed. With these data, we analyzed the characteristics of the peak ground motion value, attenuation relation, duration and acceleration response spectrum. We draw the peak acceleration contour map of the region near the epicenter. The contour line is smooth and the trend of long axis is northwest-southeast. Distribution of peak acceleration of the observed records is basically consistent with the real intensity distribution. Compared with the predicted result based on the seismic attenuation relation proposed by Yu Yanxiang and Wang Suyunon for eastern China and the Fifth-generation ground motion zonation map, the horizontal PGA and PGV of Gaoyou-Baoying earthquake are higher than the predicted results that are based on the model of Fifth-generation ground motion zonation map, while the PGV is similar with the predicted results which are based on Yu Yanxiang and Wang Suyun's model. We regressively analyzed the spatial-temporal change curves of the two types of relative ground motion durations. Compared with the predicted results proposed by Bommer et al. (2009) based on the NGA strong motion records, the durations of all the three components of this earthquake are higher. 10 typical recordings' acceleration response spectra with 5% damping are calculated, their peak periods are around 0.1~0.3s. The acceleration response spectrum of the station 32BYT, which has the largest amplitude, is considerably larger than the Chinese code design spectra, while it becomes notably smaller when the period is larger than 0.4s. Compared with the horizontal bedrock acceleration response spectrum predicted by the attenuation relationship for the eastern part of China, the observed response spectrum shape is similar with the predicted ones, while almost all the observed response spectrum values (except station 32YCT)are smaller than the predicted bedrock acceleration response spectrum. These phenomena suggest that this earthquake has a weak impact on the seismic fortification standards in this area. Using H/V single-station spectral ratio method, amplitude and site amplification effect of the two typical stations are calculated, and the results show the H/V values are obviously larger than that of ground microtremor. This suggests that the site of the station has obvious amplification effect on ground motion. 相似文献
3.
选取分布在北川-映秀中央断裂两侧断层距120 km以内的40个强震动台站的记录,对汶川地震近断层地震动竖向和水平向加速度峰值、速度峰值、竖向和水平向加速度反应谱及谱比值进行了统计分析.研究表明:(1)地震动加速度峰值有显著的上盘效应,经验衰减模型的结果表明,在距地表破裂3~60 km的范围内,龙门山发震断层上盘一侧竖向与水平向的加速度峰值要比衰减模型得到的平均值大30%~40%.上盘的加速度峰值残差大部分是正值,而断层下盘残差大部分为负;水平地震动的东西分量幅值总体要大于南北分量,东西分量衰减相对较慢.(2)地震动长周期成分较弱,加速度反应谱值随周期增大而迅速减小,在周期1.0 s 时,即使在靠近中央断裂的最大加速度反应谱值也只有0.5 g;地震动加速度反应谱谱比值(竖向/水平向)沿龙门山断层周围的分布,在较长周期(T=0.2 s, 0.5 s, 1.0 s)与短周期(T=0.05 s, 0.1 s)有明显的不同.(3)近断层竖向地震动显著,地震动加速度峰值比在(竖向/水平向)可达1.4.在龙门山发震断层的上盘,地震动加速度峰值比整体上比下盘要大,竖向地震动尤为剧烈.部分近断层记录的地震动谱比值(竖向/水平向)在短周期(< 0.1 s)甚至超过1.5,统计分析还表明谱比值在短周期段(< 0.1 s)随断层距的增大而减小. 相似文献
4.
为了研究2021年5月22日玛多MS 7.4地震地震动特征,收集16个强震台的峰值加速度和其中9个台的强震波形数据,利用峰值加速度衰减及反应谱等分析玛多MS 7.4地震强震动特征。结果表明,多数台站的PGA值都随震中距的增大而平稳下降,PGA的衰减特征与青藏区衰减关系间有较好的一致性;土层台与基岩台的加速度反应谱明显不同,震中距越小,短周期高频成分越多,衰减越快,震中距越大,长周期高频成分越少,衰减越慢;加速度反应谱的水平向与竖向比值曲线在4 s内呈现两峰一谷的现象,初步认为,距发震断层较近的野马滩1号大桥所受到的破坏及水泥路面的明显错断受水平向地震动作用的影响更大。 相似文献
5.
基于欧美规范确定了坐落在深厚覆盖层上KH抽水蓄能电站上、下库场地基本运行和最大设计地震动峰值加速度、反应谱和时程等动参数。首先依据场地区域地震烈度区划图、特征周期区划图和依据场地地质地震条件选取的5条种子实测地震动确定场地基岩输入加速度时程、峰值加速度和设计反应谱,进而基于各土层地质参数和一维弹性波传播模拟程序确定覆盖层表面的平均峰值加速度、平均反应谱和5条地震动时程,对所得到的平均反应谱和峰值加速度进行光滑处理后确定可用于各建筑物结构抗震设计的地震动参数,包括覆盖层表面水平向动力响应加速度时程、峰值加速度和设计反应谱。该方法可较好地保留输入地震动的真实动力特性,如持时、相位和频率等,为我国规范中建议的确定场地地震动参数的方法提供有益的补充。 相似文献
6.
为研究AP1000核电厂基底隔震性能,设计了缩尺比为1/40的AP1000核电厂模型结构,进行了AP1000核电厂模型基底隔震振动台试验。试验中采用铅芯橡胶隔震支座进行隔震,并选取RG1.60人工波、El Centro波和Kobe波作为地震动输入。本文从加速度响应、楼层加速度反应谱、加速度峰值放大系数、减震率等方面对隔震与非隔震核电厂结构的地震响应特性进行了研究。试验结果表明:隔震能明显减小上部结构水平向加速度响应和加速度反应谱峰值,而在隔震频率处隔震模型加速度反应谱有所增加;隔震模型由于摇摆效应在隔震频率处的水平向楼层加速度反应谱随楼层高度的升高先减小后增大;在三向输入地震动作用下,隔震和非隔震AP1000模型各楼层在竖向基频附近的竖向加速度反应谱较竖向输入的地震动放大较为明显。 相似文献
7.
根据强震动观测、实验研究与数值模拟结果表明,山脊地形对地震动具有显著影响.文章基于汶川地震主震及余震的三个地形效应观测台阵记录的三分量地震动加速度时程,经基线校正后计算得到各观测点的地面峰值加速度、峰值加速度比和反应谱比,分析山脊地形对地震地面运动的影响.结果表明:山脊地形对地震地面运动的影响显著,其地形地震效应随山脊地形的不同而变化,且地形效应具有方向性;水平向地形效应显著于垂直向;谱比是周期相关的,在所分析的周期范围内谱比不总是大于1．0. 相似文献
8.
Rotation-invariant measures of earthquake response spectra 总被引：1，自引：1，他引：0
A new procedure for combining the response spectra of two horizontal components of recorded ground motion is presented. The presented formulation accounts for different orientations of accelerometer sensors and derives the maximum and the expected (mean) horizontal response spectra at a site, both of which are invariant to rotation of sensor axes. The maximum response spectrum is derived as the peak resultant response of single degree of freedom oscillators subjected to the as-recorded ground acceleration. The expected spectrum is derived by projecting the displacement response (due to as-recorded motion) along two orthogonal axes to a principal axes in which the displacement responses are uncorrelated. This property is used to formulate an approximation for the expected response spectrum over all possible sensor orientations. A large set of accelerometric data from Europe and the Middle East is used to demonstrate the applicability of the proposed response spectral measures. 相似文献
9.
作为一种特殊的地震动,长周期地震动对结构的危害已引起国内外学者的关注。选取10条KiK-net、K-NET台网中典型的长周期地震动,以及10条国内外的短周期地震动,对比分析两者时程特征和反应谱特征的差异。将所选长、短周期地震动输入钢框架结构模型;通过非线性时程分析,研究钢框架结构在长、短周期地震动作用下的响应差异。结果表明：短周期地震动的平均地面峰值加速度是长周期地震动的3.26倍,而平均地面峰值位移比长周期地震动低10.89%;短周期地震动作用下,钢框架结构顶点加速度响应平均值是长周期地震动的5.16倍,结构顶点位移响应平均值仅比长周期地震动多0.91%;长周期地震动作用下,钢框架结构层间位移角响应较大,结构底部受影响范围更广。对于长周期地震动隐患地区的高层钢框架结构,应对长、短周期震害分别进行考虑;对于中、长周期钢框架结构,建议选用峰值位移作为抗震分析指标。 相似文献
10.
A wide variety of near-fault strong ground motion records were collected from various tectonic environments worldwide and were used to study the peak value ratio and response spectrum ratio of the vertical to horizontal component of ground motion, focusing on the effect of earthquake magnitude, site conditions, pulse duration, and statistical component. The results show that both the peak value ratio and response spectrum ratio are larger than the 2/3 value prescribed in existing seismic codes, and the relationship between the vertical and horizontal ground motions is comparatively intricate. In addition, the effect of the near-fault ground motions on bridge performance is analyzed, considering both the material nonlinear characteristics and the P~? effect. 相似文献
11.
Specially designed arrays of strong-motion seismographs near to the earthquake source are required for seismological and engineering studies of the generation and near-field properties of seismic waves. The first such large digital array, called SMART 1 (with radius 2 km and 37 accelerometers), to record substantial ground motion (up to 0·24g horizontal acceleration) became operational in late 1980 in a highly seismic region of Taiwan. During the first 6 months of operation, SMART 1 recorded nine earthquakes with magnitudes ranging from ML 3·8 to 6·9. Three were located directly below the array at focal depths of 59 to 76 km. The remaining six had shallow depths and epicentral distances from 7 to 193 km. Digital records from 27 three-component accelerographs were obtained from a magnitude 6·9 (ML) local earthquake on 29 January 1981. Representative measurements are described of seismic wave coherency and power spectrum as a function of wave number, frequency, azimuth of propagation and wave type. Acceleration waveforms varied significantly across the array for each event. On average, peak acceleration of horizontal components was about three times that of the vertical component. Relative spectral changes from earthquake to earthquake were large. 相似文献
12.
地震安全性评价工程师资格考试大纲已审定通过 总被引：12，自引：0，他引：12
把美国西部地区作为参考区,采用我国地震动参数区划图工作时所使用的美国西部地区强震资料建立参考区水平向基岩短周期加速度反应谱衰减关系;采用美国南加州地区数字宽频带记录建立参考区水平向基岩长周期加速度反应谱衰减关系。与由丰富的等震线资料统计得出的我国东部地区和西部地区的地震烈度衰减关系一起,用转换方法分别得到了我国东部和西部地区水平向基岩加速度反应谱衰减关系。对该衰减关系在重大工程地震安全性评价工作中的应用提出了建议。 相似文献
13.
软土具有高灵敏度、低强度等特性，在地震过程中极易产生震陷。基于OpenSees数值模拟方法对软土场地的震陷反应进行非线性动力有限元分析，通过改变地震动峰值加速度、频谱特性、输入方式来研究其对软土震陷的影响。结果表明，地震动峰值加速度对地基土的不均匀震陷有显著影响，地震动峰值加速度越大，震陷量显著增大，震陷影响深度更大，对水平地表造成的破坏范围也更大；地震动频谱特性对软土震陷有重要影响，当地震动卓越频率与场地自振频率相近时，其幅值越大，产生的震陷越严重；水平、竖向同时输入地震动的方式能更好地反映土体的振动及震陷响应。该研究成果对探索软土震陷的机理有一定的指导意义。 相似文献
14.
Soil amplification characteristics of earthquake ground motion were investigated in terms of peak ground acceleration and transfer function based on the Chiba array observation records. The amplification of peak ground acceleration occurred mostly at the top soft layer and was similar for the three components. The effects of non-linear response of soil deposits on the transfer function were examined. Transfer functions calculated by ensemble average were close for the two horizontal components while those obtained from a smoothing operation were generally different. Both the transfer functions from the ensemble average and the smoothing operation underestimated the gain factor around the natural frequencies. A two-step smoothing procedure was proposed and a rotary spectrum was used to improve the estimation of the transfer function. Microtremors were observed at the locations of the boreholes where seismometers are buried. The power spectrum and spatial coherency of the microtremors were compared with those of the earthquake ground motion. Emphasis was placed on the wavetypes which dominated the peaks in the power spectra. 相似文献
15.
Attenuation relations for horizontal peak ground acceleration and response spectrum in northeastern Tibetan Plateau region 总被引：1，自引：0，他引：1
Introduction Developing local attenuation relations of ground motion is one of the key steps in seismic hazard assessment. Because of inadequate strong ground motion records in China, the attenuation relations used in China are usually developed by using the transforming method (Hu, Zhang, 1983; HU, ZHANG, 1984). To use this method, we need to have both the attenuation relation of seismic intensity for the studied region and the attenuation relations of seismic intensity and ground mo-tion… 相似文献
16.
场地地震安全性评价中确定设计地震动参数方面若干问题的研究 总被引：5，自引：0，他引：5
研究了确定设计地震动参数中涉及的若干问题,其中包括基岩水平加速度反应谱衰减关系的选择、震源深度对基岩水平加速度峰值及基岩反应谱曲线的影响、强度包络线函数及输入随机相位的选择、土体非线性特性参数和土层剪切波速值的选择、设计地震动反应谱的标定等问题。在有关方面的研究中基于一个典型场地计算剖面,采用一维等效线性化模型并通过逐项变换某些研究参数的方法,研究了有关方面对设计地震动参数可能产生的影响及存在的误差和相应的规律,有关研究结果对合理确定设计地震动参数具有一定的实用价值。 相似文献
17.
本文收集了从南北地震带川滇甘陕地区263个有详细场地资料的强震台站获得的802组强震动记录，按照场地、震级和震中距等因素统计分析了竖向与水平向加速度反应谱比的形状以及不同场地、震级和震中距下不同周期段内的谱比平均值，并与建筑抗震规范GB50011—2010规定的0.65进行了比较。结果表明:竖向与水平向加速度反应谱比受场地、震级和震中距等因素的影响； Ⅰ类和Ⅱ类场地在全周期段的谱比均值基本上大于0.65；无论何种分组情况谱比均值在0.1—1.0 s周期范围内基本低于定值0.65，周期大于1.0 s的谱比均值基本上远高于0.65。因此对于大部分抗震规范直接把竖向地震作用取为水平向地震作用的0.65倍，有待商榷。本文建议根据水平向反应谱的标定方式来确定现有竖向强震动记录的竖向地震作用。 相似文献
18.
According to the epicenter distance and the site classification, the 404 groups of earthquake recordings of the main shock of the Chi-Chi, Taiwan China earthquake in 1999 are catalogued. Based on these data, we analyze the statistical features of duration, PGA, envelopes and the response spectra ratio of the horizontal and vertical components of the acceleration recordings. The results of these analyses show that the effect of site classification on the acceleration of various components is obvious; furthermore, fault direction also has certain effects on the characteristics of the horizontal components of ground motion. The detailed research results are as follows： （ 1 ） the duration of the horizontal components of acceleration records increases with the softening of the site; （2） the direction of fault slip has some effects on PGA＇s attenuation features; （3） the average envelopes of acceleration records at different distances and site dames are basically single peak functions of time and the envelopes of horizontal and vertical components of ground motion are obviously different; （4） with the same epicenter distance, EW/NS response spectrum ratios tend to approximate 1.0 as the site becomes softer and the period shorter. V/H response spectrum ratios in short periods （〈 0. 1s） increase with the softening of site, however, V/H ratios within the long-period range （ 〉 characteristic period） decrease with the softening of the site, and the decrease of V/EW ratio speeds up relatively. 相似文献
19.
地震作用下黄土边坡的动力响应特征与变形失稳机制是具有重要理论与实践意义的课题,但从动力响应频谱特性方面开展的研究还相对较少.以大型振动台模型试验获得的黄土边坡地震动峰值加速度数据为基础,通过分析其变化规律,着重从频谱特性的角度分析,讨论黄土边坡的动力失稳机制.进一步通过对坡面不同高程测点、边坡内部垂直方向以及水平方向上测点的加速度时程进行绝对加速度反应谱分析,从频谱变化角度提出黄土边坡的动力失稳机制.研究表明,黄土边坡在地震动作用下的响应过程可以分为三个阶段:弹性阶段、塑性阶段与破坏阶段;黄土边坡进入破坏阶段时均会伴随反应谱峰值的增幅或者主周期的变化,在弹性阶段反应谱加速度峰值增幅与输入地震动幅值增幅一致,进入塑性阶段后反应谱峰值增幅比输入地震动幅值增幅小;研究提出将反应谱首峰的凸显情况作为坡体破坏程度的判断依据之一. 相似文献
20.
利用近几年在川滇地区破坏性地震及汶川地震强余震中获得的951条加速度记录, 通过选取合适的衰减关系形式和距离参数, 经统计获得了川滇地区水平向峰值加速度与35个周期点对应的加速度反应谱(阻尼比0.05)衰减关系. 统计结果显示, 震级越大, 地震动随距离的衰减越慢; 加速度反应谱的短周期部分随距离的衰减明显快于长周期部分; 中强地震在近场也会产生较大的峰值加速度和较高的短周期加速度反应谱. 由于统计资料的非完整性, 本文统计结果尚不宜直接应用于相关工程场地的设计地震动参数确定中. 但本文结果与目前由转换方法得到的我国西部地震动参数衰减规律的较大差异提示: 进一步深入研究我国地震动参数衰减规律应是紧迫而重要的任务. 相似文献