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沈阳2×200兆瓦低温核供热站厂址基准地面运动参数的确定 总被引：2，自引：0，他引：2
本文在综合厂址、近区域及区域地震地质资料的基础上,根据有关规范的要求,采用地震构造法、最大历史地震法和概率法分别计算了沈阳2×200兆瓦低温核供热站厂址的极限安全地震动SL-2,计算结果分别为200Gal、125Gal和170Gal。取三者最大值,厂址SL-2应当是200gal。厂址基岩地面运动SL-2水平向加速度反应谱取确定性法和概率法计算曲线的外包线作为用于厂址的基岩加速度反应谱。 相似文献
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地震动输入界面的选取对深软场地地震效应的影响 总被引：4，自引：0，他引：4
以天津和上海两个典型的深厚软弱场地为研究背景，探讨了地震动输入界面对场地地表地震动参数的影响。对于场地1(天津)和场地2(上海)，分别选择7个和8个剪切波速(υs)大小不同的土层位置作为地震动输入界面，并选用Taft、Northridge地震加速度记录和南京人工波作为输入地震动，将Taft波、Northridge波和南京人工波的加速度峰值水平调整为0．35m／s^2、0．70m／s^2和0．98m／s^2，用SHAKE91程序对这两个场地进行了不同的地震动输入界面、输入地震波和峰值加速度水平的128种组合的场地地震反应分析。与从假想基岩面(υs≥500m／s)输入地震动的结果(假想的实际值)相比，可得到如下结论：(1)随着地震动输入界面深度(剪切波速)的增加，场地地表加速度反应谱逐渐地向实际值接近；(2)地震动输入界面的深度相同时，地震动加速度峰值水平越高，两者的加速度反应谱谱值的相对差异也越大；(3)对于一般建筑物，可以把剪切波速为400m／s左右的土层作为地震动输入界面；对于中长周期的建筑物，则应慎重选择地震动输入界面，最好选取υs≥500m／s^2的土层或基岩面作为地震动输入界面。 相似文献
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《地震地质》2017,(5)
福岛核事故后,地震作为初始事件引发核电厂严重事故的问题引起了广泛关注。在此背景下,中国核电厂相继开展了抗震裕度评价,但在评价中选用了不同的地震谱形。基于美国针对早期运行核电厂开展的抗震裕度评价方法和中国核电厂址的地震危险性背景分析,对比了中美两国核电厂抗震设计基准的差异,针对中国目前的情况,建议优先对采用二代加堆型的运行电厂进行抗震裕度评价。通过将RG1.60谱与归一化厂址特定SL-2级加速度反应谱进行对比分析,发现部分核电厂址反应谱谱形在高频部分超过了RG1.60谱,对于这类厂址,直接放大标准反应谱作为抗震裕度地震是不恰当的。对于采用二代加堆型的核电厂,选择了某个厂址特定SL-2级地震动与标准设计比较接近的核电厂址进行了分析,采用不同方法确定其抗震裕度地震,结果表明0.3g标定的NUREG0098中值谱在平台段和长周期部分明显低于相同PGA水平的一致概率谱和设定地震谱,三者都能被0.3g标定的RG1.60谱所包络。考虑到中国运行电厂的抗震设计特点,为了评价核电厂实际抗震能力相对于厂址的抗震安全裕度,可以采用一致概率谱或设定地震谱;为了评价二代加运行核电厂实际抗震能力相对设计基准地震动的抗震安全裕度,建议采用给定PGA标定的RG1.60谱。 相似文献
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人造地震动的时域叠加法和反应谱整体逼近技术 总被引：11，自引：2，他引：11
介绍了两种新的人造地震动的加速度反应谱拟合方法:其一是时域叠加法．该方法通过在时程上叠加一谐波时程来调整某一反应谱控制点的值．其特点是交叉干扰小，计算量小且能兼顾强度包线的要求；其二是反应谱整体逼近法．其特点是在调整某一由幅值谱Ak及其相位谱k(k＝0，1，2，，n)决定的时程Ra(t)时，用反应谱与目标谱在各个控制点上相对误差Ej(j＝1，2，3，，M)的均方根值Vr＝是否减小来判定任一幅值谱Ak调整的方向．本文指出，由于Ej及Vr均是Ak及k的函数，所以，合成加速度时程中的反应谱拟合问题可变成寻找Vr极小点的数学问题．时域叠加法受最高截止频率的限制，不适用于反应谱高频部分的拟合．反应谱整体逼近法受FFT算法频率分布特征的限制，使反应谱低频部分的控制点密度不能太大．大量的试算结果表明，以上两种方法相互补充，可取得良好的拟合效果．文中还指出，由于有了较好的反应谱拟合方法，可在反应谱拟合的同时，对加速度时程的峰值加速度及峰值速度进行拟合． 相似文献
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针对核电厂CAP1400核岛结构地震反应问题，构建了核岛屏蔽厂房和辅助厂房整体结构的3个分析模型:原型和1/16、1/40缩尺模型，并在AP000谱和RG1.60谱地震动输入下进行了有限元模拟对比分析，探讨了振动台试验模型缩尺处理的合理性和精确性。研究表明，基于缩尺模型得到的结构自振频率相对于原型结构模型有所降低，降低幅度在8.5%以内；结构模型的缩尺对结构反应峰值加速度和高频（大于3Hz）加速度反应谱的影响较为显著，但对较低频（小于3Hz）的加速度反应谱影响较小；模型缩尺对结构不同方向反应的影响中，刚度越大的方向其影响越大。进一步将结构模型数值模拟结果与1/16缩尺模型的振动台试验结果进行了比较分析，试验给出的结构自振频率远低于模型数值模拟结果，但原型和1/16缩尺模型数值模拟得到的结构反应均与试验结果较为接近。基于模型数值模拟和振动台试验研究，认为对于缩尺比1/16或更大的模型可以忽略模型的缩尺效应。 相似文献
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液化土层对地表加速度反应谱的影响 总被引：4，自引：0，他引：4
采用一种改进的有效应力方法研究土层液化对地表加速度反应谱的影响，分析中考虑了砂层的厚度、埋深和输入地震波的幅值和波型等因素。分析结果表明，土层液化使地表加速度反应谱的特征周期至少延长0．1秒以上，使原Ⅱ类场地变为Ⅲ类场地，高烈度时易变成Ⅳ类场地，反应谱中周期0．8秒-1．0秒是液化砂层加震或减震的一个分界点，液化对反应谱短周期分量具有一定的减震作用，而对长周期分量有非常显著的放大作用。 相似文献
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2003年2月24日新疆巴楚—伽师地区发生了Ms6．8级地震，极震区地震烈度Ⅸ度．布设在西克尔水库、伽师、巴楚强震固定地震台获取了该震的加速度记录。各地震台震中距分别为25km,47km、113km，记录到最大水平加速度峰值分别为85．39cm／8／8、50．71cm／s／s、76．03cm/s/s，反应谱的卓越周期为0．45—0．51s．对一次余震也作了介绍，同时提出几个问题供地震学者、地质学家及地震工程人员进一步探讨． 相似文献
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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
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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
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SMART-1台阵记录的长周期反应谱特性 总被引：3，自引：0，他引：3
利用台湾SMART－1台阵的数字强震仪加速度记录分析了同类场地上的地震动长周期分量特性，结果表明：同一次地震震中距基本相同的同类场地加速度反应谱短周期部分有较明显的差别，长周期部分则基本相同；震级和震中距对短周期反应谱影响明显，对长周期反应谱也有一定影响。最后将SMART－1台阳场地的平均谱与新的建筑抗震设计规范修订稿中提出的设计反应谱作了比较。 相似文献
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Markušić Snježana Herak Marijan Herak Davorka Ivančić Ines 《Studia Geophysica et Geodaetica》2002,46(1):83-92
Residuals of the peak horizontal acceleration for site-independent attenuation relations are shown to have weak positive correlation with the average observed peak horizontal/vertical acceleration ratio (q) at the recording site. This ratio systematically increases as the hardness of the soil decreases. Taking the average observed q at the recording station into account reduces the scatter of data slightly in fitting the assumed peak acceleration attenuation law. If the soil classification of the data is available, soil dependence is found to be weaker if the data are corrected for the effect of q prior to regression. This correction reduced the mean value of q = 1.85 for the Dinarides area to q = 1.52, which, on the average, is characteristic of rock sites. 相似文献
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A simple calculation procedure for estimating absolute maximum slip displacement of a freestanding rigid body placed on the ground or floor of linear/nonlinear multi‐storey building during an earthquake is developed. The proposed procedure uses the displacement induced by the horizontal sinusoidal acceleration to approximate the absolute maximum slip displacement, i.e. the basic slip displacement. The amplitude of this horizontal sinusoidal acceleration is identical to either the peak horizontal ground acceleration or peak horizontal floor response acceleration. Its period meets the predominant period of the horizontal acceleration employed. The effects of vertical acceleration are considered to reduce the friction force monotonously. The root mean square value of the vertical acceleration at the peak horizontal acceleration is used. A mathematical solution of the basic slip displacement is presented. Employing over one hundred accelerograms, the absolute maximum slip displacements are computed and compared with the corresponding basic slip displacements. Their discrepancies are modelled by the logarithmic normal distribution regardless of the analytical conditions. The modification factor to the basic slip displacement is quantified based on the probability of the non‐exceedence of a certain threshold. Therefore, the product of the modification factor and the basic slip displacement gives the design slip displacement of the body as the maximum expected value. Since the place of the body and linear/nonlinear state of building make the modification factor slightly vary, ensuring it to suit the problem is essential to secure prediction accuracy. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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Yoshimitsu Fukushima Onur Köse Tekin Yürür Philippe Volant Edward Cushing Richard Guillande 《Journal of Seismology》2002,6(3):379-396
The 17 August 1999 Kocaeli earthquake in Turkey produced a majorsurface rupture. We traced this surface rupture from Gölcük toDüzce and located it accurately by using GPS. The closest distancefrom the surface rupture to the strong motion observation sites weredetermined. Then the attenuation characteristics of the observed peakground acceleration were compared with the attenuation relation given byFukushima and Tanaka (1992), which is suitable for the near-fault zone inJapan and gives results that closely match data recorded during the 1995Hyogo-ken Nanbu earthquake in Japan. Although this attenuation relationwas developed for Japan, we found that it agreed well with the KOCAELIearthquake. Furthermore, the observed spectral acceleration of 5%damping was compared with the building design code of Turkey and theobserved level was lower than the code. 相似文献
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Pseudo-static analysis is commonly used to design earth structures. Most pseudo-static methods of analysis require a computer program. This paper presents a simple closed form solution of seismic stability analysis by extending Francais–Culmann's analysis. The analysis is valid for a slope with the most critical planar mechanism and under the influence of horizontal and vertical earthquake accelerations. The resulting permanent displacement is discussed and demonstrated using several real earthquake records. The simplicity of extended Francais–Culmann's solution allows it to be used for preliminary design and classroom instruction. 相似文献
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A new integrated measuring system with eight force-balance accelerometers is proposed to obtain a direct measurement of six degree-of freedom （DOF） ground motions, including three rotational and three actual translational acceleration components without gyroscopes. In the proposed measuring system, the relationship between the output from eight force-balance accelerometer and the six DOF motion of the measuring system under an earthquake are described by differential equations. These equations are derived from the positions and directions of the eight force-balance accelerometers in the measuring system. The third-order Runge-Kutta algorithm is used to guarantee the accuracy of the numerical calculation. All the algorithms used to compute the six DOF components of the ground motion are implemented in a real-time in Digital Signal Processor （DSP）. The distortion of the measured results caused by position and direction errors of the accelerometers in the measuring system are reduced by multiplying a compensation coefficient C to the output and subtracting static zero drift from the measured results, respectively. 相似文献
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Ground motion prediction equations based on shallow crustal earthquakes in Georgia and the surrounding Caucasus 
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下载免费PDF全文 Jorjiashvili Nato Shengelia Ia Godoladze Tea Gunia Irakli Akubardia Dimitri 《地震科学（英文版）》2022,35(6):497-509
Strong ground motions caused by earthquakes with magnitudes ranging from 3.5 to 6.9 and hypocentral distances of up to 300 km were recorded by local broadband stations and three-component accelerograms within Georgia’s enhanced digital seismic network. Such data mixing is particularly effective in areas where strong ground motion data are lacking. The data were used to produce models based on ground-motion prediction equations (GMPEs), one benefit of which is that they take into consideration information from waveforms across a wide range of frequencies. In this study, models were developed to predict ground motions for peak ground acceleration and 5%-damped pseudo-absolute-acceleration spectra for periods between 0.01 and 10 s. Short-period ground motions decayed faster than long-period motions, though decay was still in the order of approximately 1/r. Faulting mechanisms and local soil conditions greatly influence GMPEs. The spectral acceleration (SA) of thrust faults was higher than that for either strike-slip or normal faults but the influence of strike-slip faulting on SA was slightly greater than that for normal faults. Soft soils also caused significantly more amplification than rocky sites. 相似文献