کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4927398 1431704 2016 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Detailed site effect estimation in the presence of strong velocity reversals within a small-aperture strong-motion array in Iceland
ترجمه فارسی عنوان
برآورد اثرات مفصلی سایت در حضور چرخشهای قوی در یک آرایه حرکت قوی دیافراگم کوچک در ایسلند
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات مهندسی ژئوتکنیک و زمین شناسی مهندسی
چکیده انگلیسی


- Detailed site response analysis using earthquake recordings and microseismic data.
- Consistent results between different methods of site response analysis.
- The underlying soil structure is characterized by strong velocity reversals.
- Wave propagation methods fail to reproduce the predominant frequencies of the soil structure.
- Modeling the soil structure as a dynamic system captures the predominant frequencies.

The rock site characterization for earthquake engineering applications in Iceland is common due to the easily exposed older bedrock and more recent volcanic lava rock. The corresponding site amplification is generally assumed to be low but has not been comprehensively quantified, especially for volcanic rock. The earthquake strong-motion of the Mw6.3 Ölfus earthquake on 29 May 2008 and 1705 of its aftershocks recorded on the first small-aperture strong-motion array (ICEARRAY I) in Iceland showed consistent and significant variations in ground motion amplitudes over short distances (<2 km) in an urban area located mostly on lava rock. This study analyses the aftershock recordings to quantify the local site effects using the Horizontal to Vertical Spectral Ratio (HVSR) and Standard Spectral Ratio (SSR) methods. Additionally, microseismic data has been collected at array stations and analyzed using the HVSR method. The results between the methods are consistent and show that while the amplification levels remain relatively low, the predominant frequency varies systematically between stations and is found to correlate with the geological units. In particular, for stations on lava rock the underlying geologic structure is characterized by repeated lava-soil stratigraphy characterized by reversals in the shear wave velocity with depth. As a result, standard modeling of HVSR using vertically incident body waves does not apply. Instead, modeling the soil structure as a two-degree-of-freedom dynamic system is found to capture the observed predominant frequencies of site amplification. The results have important implications for earthquake resistant design of structures on rock sites characterized by velocity reversals.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Soil Dynamics and Earthquake Engineering - Volume 89, October 2016, Pages 136-151
نویسندگان
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