STARTING ESTIMATES OF SEISMIC SITE COEFFICIENTS ALONG 2D SEMI-ELLIPTICAL SHAPED HILLS
In the recent past, there have been numerous cases of recorded motion and observed earthquake damage pointing toward topographic amplification as an important effect. Very high recorded accelerations during earthquakes have been sometimes attributed to topographic effects of hills as one basic type of local surface irregularities. In this paper the results of a comprehensive parametric study for estimating the site coefficients in areas with 2D semi-elliptical shaped hills has been presented. Using adequate number of accelerograms as well as numerically calculated transfer functions of 2D semi-elliptical shaped hills, the extension capability of the Borcherdts method to 2D semi-elliptical shaped hills has been investigated. By frequency domain analysis and then inverse Fourier transform, the amplified accelerograms along the hills were obtained. The achieved results accentuated the efficiency of the Borcherdts method in 2D microzonation studies. Moreover, it has been shown that the site coefficients vary between 1.0 and 1.7, are comparable to the 1D site coefficients usually suggested by the seismic codes, differ from short to long periods and exceed the maximum value of 1.4 proposed by the AFPS (1990) code for seismic design of structures in topographic areas.
site effect topography semi-elliptical shaped hill amplification response spectra site coefficient
A. Taghavi M. Kamalian M.H. Baziar A. Sohrabi-Bidar M.K. Jafari
Dept. of Civil Engineering, Iran University of Science and Technology, Tehran, Iran Geotechnical Engineering Research Center, International Institute of Earthquake Engineering and Seis Seismology Engineering Research Center, International Institute of Earthquake Engineering and Seismo
国际会议
14th World Conference on Earthquake Engineering(第十四届国际地震工程会议)
北京
英文
2008-10-12（万方平台首次上网日期，不代表论文的发表时间）