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1.
基于ABAQUS显式有限元并行计算平台,采用大尺度二维精细化有限元非线性分析方法,研究泉州盆地地震效应特征.结果表明:(1)与基岩输入地震动相比,地表峰值加速度总体呈放大效应,且盆地不同位置的放大效应存在明显差异;(2)地表或基岩剧烈起伏及土层横向分布极不均匀处,地震动易产生局部聚集效应,相应地表地震动呈显著放大或缩小效应;地表加速度反应谱产生双峰甚至多峰现象.(3)在土层竖向、横向分布不均匀处,峰值加速度沿深度方向呈非单调递减,加速度反应谱沿深度存在较大差异.场地地震效应的二维非线性分析法能在一定程度上反映特殊场地条件对地震动效应的影响,该结果可为泉州盆地及类似盆地的场地设计地震动参数的确定提供参考依据.  相似文献   
2.
以安徽省滁州市地震小区划场地为研究对象,基于ABAQUS显式有限元并行计算平台,采用大尺度二维精细化有限元非线性分析方法,研究了局部地质条件差异对场地地震效应的影响。结果表明:该场地地震动放大效应明显,河漫滩地表PGA放大效应尤为显著;相比一级阶地,河漫滩地表加速度反应谱谱形加宽,谱峰向长周期方向移动,移动幅度约为0.05~0.25S,相应的特征周期增大。地表加速度反应谱呈双峰甚至多峰特征,大尺度场地非线性有限元分析能定性反映出局部地质条件对场地地震效应特性的影响,可为城市地震小区划提供更为合理的科学依据。  相似文献   
3.
文中以某一实际工程为例,讨论工程场地地震安全性评价中加速度反应谱规准化对工程场地地震位移时程所带来的影响。数值结果表明,根据规准化加速度反应谱得出的位移时程存在很大的误差。建议在工程场地地震安全性评价工作中,不宜进行加速度反应谱的标定工作。  相似文献   
4.
本文在统计了大量强震记录的基础上,分别研究了双规准加速度反应谱和双规准速度反应谱的特性,进行了对比分析,并分别得出了定量分析的结果。研究结果表明,双规准加速度反应谱在短周期段有很好的统一性,而双规准速度反应谱在长周期段的统一性较好,这种规律性对于认识地震动的特性、改进抗震设计反应谱具有重要的意义。  相似文献   
5.
A revised Italian strong motion archive has become available since July 2007, including all the records of the strongest events occurred from 1972 to 2004. It contains the uncorrected and corrected accelerograms and the metadata relevant to seismic events, recording stations and instruments added after a careful revision. The availability of this archive allowed us to perform a first step towards an update of the reference ground motion prediction equations for Italy, which were evaluated by Sabetta and Pugliese in (Bull Seismol Soc Am 77:1491–1513, 1987), for peak ground acceleration and velocity, and subsequently extended to the 5% damped pseudovelocity response spectra in 1996. A subset with the 27 major earthquakes occurred in Italy from 1972 to 2002, in the magnitude range 4.6–6.9, was extracted and 235 good quality waveforms were selected, recorded at distances up to 183 km. The goodness of fit of the Sabetta and Pugliese (Bull Seismol Soc Am 86:337–352, 1996) model was explored using two independent statistical approaches (Spudich et al. Bull Seismol Soc Am 89:1156–1170, 1999 and Scherbaum et al. Bull Seismol Soc Am 94:2164–2185, 2004). The results obtained show that the Sabetta and Pugliese (Bull Seismol Soc Am 77:1491–1513, 1987) does not adequately fit the new strong-motion data set, for its small standard deviation and its non-zero bias. In particular, the most noteworthy result is that the Sabetta and Pugliese (Bull Seismol Soc Am 77:1491–1513, 1987) over-predicts peak ground acceleration and velocity at rock sites. New coefficients for the prediction of horizontal peak ground acceleration, peak ground velocity and acceleration response spectra, adopting the same functional form in Sabetta and Pugliese (Bull Seismol Soc Am 77:1491–1513, 1987), were then evaluated in order to fit the new data set. This paper illustrates the steps made to update the existing ground motion prediction equations for Italy, discusses their limitations and provides the basis for future developments.  相似文献   
6.
竖向与水平向地震动加速度反应谱比特性分析   总被引:2,自引:0,他引:2  
本文采用全球范围128次地震的3235组三分量强地面运动记录,分析了其加速度竖向分量反应谱与水平分量反应谱的比值(V/H)的总体特征,研究了V/H随震级、震中距、局部场地条件和震源机制的变化关系。研究结果表明:(1)场地越硬,长周期段V/H越大,短周期段则相反;(2)震级越大,长周期段V/H越大,短周期段变化不明显;(3)短周期段V/H随震中距增大而减小;(4)对于大震(M>7),长周期段V/H随震中距增大而减小;而对于中强震(M<7),比值在近场(R<60km)随震中距增加而增大,在远场则随震中距增加而减小;(5)V/H与震源机制也有一定的关系。  相似文献   
7.
The issue addressed in this paper is the objective selection of appropriate ground motion models for seismic hazard assessment in the Pyrenees. The method of Scherbaum et al. (2004a) is applied in order to rank eight published ground motion models relevant to intraplate or to low deformation rate contexts. This method is based on a transparent and data-driven process which quantifies the model fit and also measures how well the underlying model assumptions are met. The method is applied to 15 accelerometric records obtained in the Pyrenees for events of local magnitude between 4.8 and 5.1, corresponding to moment magnitudes ranging from 3.7 to 3.9. Only stations at rock sites are considered. A total of 720 spectral amplitudes are used to rank the selected ground motion models. Some control parameters of these models, such as magnitude and distance definitions, may vary from one model to the other. It is thus important to correct the selected models for their difference with respect to the magnitude and distance definitions used for the Pyrenean data. Our analysis shows that, with these corrections, some of the ground motion models successfully fit the data. These are the Lussou et al. (2001) and the Berge-Thierry et al. (2003) models. According to the selected ground motion models, a possible scenario of a magnitude 6 event is proposed; it predicts response spectra accelerations of 0.08–0.1 g at 1 Hz at a hypocentral distance of 10 km.  相似文献   
8.
宋和平  柔洁 《内陆地震》1990,4(3):239-246
研究了1985年乌恰余震取得的加速度记录,从地质及地球物理的角度探讨一些加速度异常点。分析了记录的峰值加速度与震害及场地烈度的对应关系。对比了竖向和水平向加速度、速度反应谱及谱与震级的变化特征。  相似文献   
9.
Underground coal and copper ore exploitation in two Polish mining regions causes mining tremors and a series of other negative phenomena in the environment. Although these tremors are strictly connected with human activity, they differ considerably from other paraseismic vibrations. The moment of their occurrence is not to be foreseen likewise for earthquakes. The main problem discussed in the paper was formulated as the neural network evaluation of a relation between mining tremor energies, epicentral distances and acceleration response spectra. Back-propagation neural networks with Resilient back-propagation learning method were used. Each input vector included information about the mining tremor energy and the epicentral distance. Values of acceleration response spectrum were expected as the outputs of neural networks. Neurally evaluated spectra were compared with spectra computed on the basis of experimental data. After the network is trained and tested, it can be used for mapping of new data of mining tremor energies and epicentral distances into the spectra. Then, what is the substantial advantage of neural approach, the prediction of acceleration response spectra can be performed without recording of surface vibrations. In the light of the results, it is visible that the presented way of computation of acceleration response spectra can be peculiarly applied to prognosis of mining tremors influences on structures.  相似文献   
10.
The authors proposed a method for obtaining high-quality acceleration seismograms from velocity type seismograms of digital Seismographic network, and took as an example the analysis and processing of the seismograms of a same earthquake that was simultaneously recorded by velocity seismograph CTS1-EDAS24 and strong motion seismograph EST-Q4128 installed in Jixian Station, Tianjin. The calculation steps and the processing method have been discussed in detail. From the analysis and the comparison of the obtained results, it is concluded that the proposed method is simple and effective, and it broadens the application of digital seismographic network.  相似文献   
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