Site effect classification based on microtremor data analysis using a concentration–area fractal model

Abstract

Abstract. The aim of this study is to classify the site effect using concentration-area (C-A) fractal model in Meybod city, central Iran, based on microtremor data analysis. Loglog plots of the frequency, amplification and vulnerability index (k-g) indicate a multifractal nature for the parameters in the area. The results obtained from the C-A fractal modelling reveal that proper soil types are located around the central city. The results derived via the fractal modelling were utilized to improve the Igarashi (1970, 1971) classification results in the Meybod city. The resulting categories are: (1) hard soil and weak rock with frequency of 6.2 to 8 Hz, (2) stiff soil with frequency of about 4.9 to 6.2 Hz, (3) moderately soft soil with the frequency of 2.4 to 4.9 Hz, and (4) soft soil with the frequency lower than 2.4 Hz.

Studying Petrology and Determining Tectonic Setting of Bidkhan Area Southeast of Iran

“…There is also malachite within frameworks of some feldspar crystals. Secondary minerals of the outcrops from these regions consist of sericite, illite, clay minerals, malachite, apak, oxides-hydroxides of iron, chlorite, epidote and quartz (Figure 11) [12].…”

Studying the high frequency seismic signals for enhanced knowledge of the shallow Earth structure and soil investigation

“…Kanai (1957) became the first scientist to introduce the concept of using microtremors to determine the soil's natural frequency of vibration which can evaluate the soil's interaction with earthquake energy. Several subsequent studies were conducted to determine the "soil response" to the earthquake energy and its effects on buildings (Aki, 1957;Kanai and Tanaka, 1961;Kanai, 1962;Nogoshi and Igarashi, 1970;Kagami et al, 1982Kagami et al, & 1986Rogers et al, 1984;C ¸elebi et al, 1987;Lermo et al, 1988;ECP, 1993;Nakamura, 1989Nakamura, , 1997Nakamura, & 2000Bour et al, 1998;Diagourtas et al, 2002;Gamal, 2009;Harutoonian et al, 2012;Mahajan et al, 2012;Hunstad et al, 2013;Adib et al, 2015;Akkaya, 2015;Ridwan et al, 2014;Jiang et al, 2016;Singh et al, 2017;Gamal et al, 2019& 2020, Gamal and Maher, 2022. Mucciarelli (1998) excluded some surface sources such as winds or sounds from sources such as winds entering the asphalt layers, making asphaltic waves.…”