Estimation of topographical effects at Narni ridge (Central Italy): comparisons between experimental results and numerical modelling
Estimation of topographical effects at Narni ridge (Central Italy): comparisons between experimental results and numerical modelling
复制标题
纳尔尼山脊（意大利中部）地形影响的估计：实验结果与数值模型之间的比较
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
M. Kamalian
中科院分区：
文献类型：
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作者：
S. Lovati;M. K. Bakavoli;Marco Massa;G. Ferretti;F. Pacor;R. Paolucci;E. Haghshenas;M. Kamalian
在目前的工作中，Narni山脊（中意大利）的地震现场响应进行了评估，通过比较实验结果和数值模拟。有人居住的纳尼村位于亚平宁山脉中部，位于一个陡峭的巨大石灰岩山脊的顶部。从2009年3月到9月，在该地点安装了10个弱运动台站，其中3个位于脊底，7个位于脊顶。测速网络记录了642个事件的ML高达5.3和震源距离高达约100公里。大量的数据与2009年4月的拉奎拉序列有关。场地响应分析使用参考（标准光谱比，SSR）和非参考光谱技术（水平垂直光谱比，HVSR）。此外，进行方向分析，以评估相对于选定的源站点路径的脊方向的影响。一般来说，实验结果表明，几乎所有的站安装在沿着波峰4和5赫兹之间的频率的放大系数。SSR技术在垂直于脊的主伸长方向上提供高达4.5的放大因子。从数据分析中获得的结果被用作二维和三维数值模拟的目标，分别使用混合有限元-边界元法和边界元法进行二维和三维建模。在一般情况下，通过数值模拟得到的结果很好地拟合放大频率的范围方面的实验数据，但他们低估了约2倍的观察到的放大。
In the present work the seismic site response of Narni ridge (Central Italy) is evaluated by comparing experimental results and numerical simulations. The inhabited village of Narni is located in central Apennines at the top of a steep massive limestone ridge. From March to September 2009 the site was instrumented with 10 weak-motion stations, 3 of which located at the base of the ridge and 7 at the top. The velocimetric network recorded 642 events of ML up to 5.3 and hypocentral distance up to about 100 km. The great amount of data are related to the April 2009 L’Aquila sequence. The site response was analyzed using both reference (standard spectral ratio, SSR) and non reference spectral techniques (horizontal to vertical spectral ratio, HVSR). Moreover directional analyses were performed in order to evaluate the influence of the ridge orientation with respect to the selected source-site paths. In general the experimental results show amplification factors for frequencies between 4 and 5 Hz for almost all stations installed along the crest. The SSR technique provides amplification factors up to 4.5 in a direction perpendicular to the main elongation of the ridge. The results obtained from the data analyses were used as a target for bidimensional and tridimensional numerical simulations, performed using a hybrid finite-boundary element method and a boundary element method for 2D and 3D modelling, respectively. In general, the results obtained through numerical simulation fit well the experimental data in terms of range of amplified frequencies, but they underestimate by a factor of about 2 the observed amplifications.