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S wave inelastic attenuation and site effect in the northern Tianshan area

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Acta Seismologica Sinica(English Edition) 2007年第2期20卷 188-193页

作者：姜慧高孟潭俞言祥唐丽华 Earthquake Administration of Guangdong Province Institute of Geophysics China Earthquake Administration Earthquake Administration of Xinjiang Uygur Autonomous Region

In this paper, according to the relationship of observation spectrum with source spectrum, travel-path attenuation factor and site effect, we use the digital seismic data of moderate-small earthquakes to invert the soft rock site effect and S wave inelastic attenuation under the constraint of site effect, and determine the parameters of path and site. The parameters obtained by this method exclude the topographic effect of seismic stations, and truly reflect the seismic effect of free soft rock sites and the S wave inelastic attenuation in the studied region. The average soft rock site effect is about 1.5 times in the frequency domain of 2-4 Hz and the S wave quality factor is obtained as Qs=278f0.346, which can be directly applied to the stochastic modeling of ground motions in the studied region.

关键词： S wave quality factor site effect inelastic attenuation northern Tianshan area

site effects by generalized inversion technique using strong motion recordings of the 2008 Wenchuan earthquake

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Earthquake Engineering and Engineering Vibration 2013年第2期12卷 165-184页

作者： Ren Yefei Wen Ruizhi Hiroaki Yamanaka Toshihide Kashima Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake Administration Tokyo Institute of Technology Building Research Institute

The generalized inversion of S-wave amplitude spectra from the free-field strong motion recordings of the China National Strong Motion Observation Network System （NSMONS） are used to evaluate the site effects in the Wenchuan area. In this regard, a total of 602 recordings from 96 aftershocks of the Wenchuan earthquake with magnitudes of M3.7-M6.5 were selected as a dataset. These recordings were obtained from 28 stations at a hypocenter distance ranging from 30 km to 150 km. The inversion results have been verified as reliable by comparing the site response at station 62WUD using the Generalized Inversion Technique （GIT） and the Standard Spectral Ratio method （SSR）. For all 28 stations, the site predominant frequency F and the average site amplification in different frequency bands of 1.0-5.0 Hz, 5.0-10.0 Hz and 1.0-10.0 Hz have been calculated based on the inversion results. Compared with the results from the horizontal-to-vertical spectral ratio （HVSR） method, it shows that the HVSR method can reasonably estimate the site predominant frequency but underestimates the site amplification. The linear fitting between the average site amplification for each frequency band and the V20 （the average uppermost-20 m shear wave velocity） shows good correlation. A distance measurement called the asperity distance DAspt is proposed to reasonably characterize the source-to-site distance for large earthquakes. Finally, the inversed site response is used to identify the soil nonlinearity in the main shock and aftershocks of Wenchuan earthquake. In ten of the 28 stations analyzed in the main shock, the soil behaved nonlinearly, where the ground motion level is apparently beyond a threshold ofPGA 〉 300 cm/s^2 or PGV 〉 20 cm/s, and only one station coded 51SFB has evidence of soil nonlinear behavior in the aftershocks.

关键词： generalized inversion technique site effect Wenchuan earthquake soil nonlinearity predominant frequency site amplification

Numerical Modelling of Seismic site effects Incorporating Non-linearity and Groundwater Level Changes

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Journal of Earth Science 2010年第6期21卷 931-940页

作者： Dominik Ehret Joachim Rohn Dieter Hannich Carlos Grandas Gerhard Huber Department of Applied Geology University of Erlangen-Nuremberg Department of Applied Geology University (TH) of Karlsruhe Institute of Soil and Rock Mechanics University (TH) of Karlsruhe

In the past decades, the necessity for detailed earthquake microzonation studies was recognized worldwide. Therefore, different approaches were established and applied. Unfortunately, the majority of these approaches are not based on pre-existing field data but require extensive seismic measurements and investigations. Furthermore, these approaches incorporate non-linearity inadequately and cannot take groundwater level changes into account. For this purpose, notably numerical models are most suitable. These models require a good knowledge of the local geological conditions （especially of the uppermost unconsolidated units）, information about the geotechnical parameters of these units, and a hydrogeological model of the investigated area. Most of this information can be obtained from geotechnical investigations and surveys that have already been carried out in most densely populated areas. In a case study for Bucharest City, non-linear analyses were performed using software that is based on the visco-hypoplastic constitutive law. The results indicate that groundwater level changes have an important influence on duration and amplitude of ground response and thus should be considered for seismic microzonation studies. This approach ean be used to display site effects and to identify different microzones taking different earthquake magnitudes and groundwater levels into account.

关键词： microzonation site effect visco-hypoplasticity non-linearity Bucharest Romania.

Introducing an effective coherence function to generate non-uniform ground motion on topographic site using time-domain boundary element method

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Earthquake Engineering and Engineering Vibration 2021年第1期20卷 89-100页

作者： Mohsen Isari Reza Tarinejad Faculty of Civil Engineering University of TabrizTabrizEast Azerbaijan ProvinceIran

In this study,a comprehensive parametric analysis was performed on non-uniform excitation of V-shaped topography using the boundary element method in time *** this purpose,wave scattering analysis was carried out on a topography subjected to the SV-wave for different predominant frequencies and shape *** on the numerical results,new coherence and time delay functions are proposed to generate non-uniform ground motion for topographic *** efficiency and accuracy of the proposed functions for real engineering problems are indicated by comparison with observations reported in previous literature.

关键词： site effect time delay boundary element method amplification coherence function

Research on the ShakeMap System with Consideration of site effects

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Earthquake Research in China 2010年第2期24卷 211-221页

作者： Chen Kun Yu Yanxian Gao Mengtan Institute of Geophysics China Earthquake Administration Beijing 100081 China

In accordance with the principle of similarity in geology and topography, the Vs^30 （the average shear-velocity down to a 30m depth below the surface） approximation of sites is acquired by correlation between Vs^30 and slopes after calculating the maximum slope of topography using the 30-sec Chinese Mainland DEM （Digital Elevation Model） data set. site-amplification factors are then quantified with Vs^30 and applied to the ShakeMap system developed by this study to revise ground-motion amplitudes on bedrock estimated from empirical relationships. Finally, the distribution of ground motion parameters on the surface is obtained. This article also introduces the calculation process, calculation models of the ShakeMap systems and related software systems. In conclusion, certain examples indicate that the ShakeMap system is feasible in the Chinese Mainland.

关键词： Topographic Slope Average shear-wave velocity site effect ShakeMap

Development of seismic force requirements for buildings in Taiwan

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Earthquake Engineering and Engineering Vibration 2009年第3期8卷 349-358页

作者： Juin-Fu Chai Tsung-Jen Teng Keh-Chyuan Tsai Center for Research on Earthquake Engineering

This paper describes static and dynamic procedures to calculate seismic demand specified by the current seismic design code for buildings in Taiwan, which was issued in 2005. For design levels with a return period of 475 years, the design spectral response acceleration can be developed for general sites, near-fault sites and Taipei Basin. In addition, in order to prevent building collapse during extremely large earthquakes and yielding of structural components and elements during frequent small earthquakes, the required seismic demands at the maximum considered earthquake level （MCE, 2%/50 years） and operational level are also included in the new seismic design *** dynamic analysis procedures, both the response spectrum method and time history method are specified in the new seismic design code. Finally, procedures to generate spectrum compatible ground motions for time history analysis are illustrated in this paper.

关键词： building code seismic force requirement design spectrum spectrum compatible design ground motion site effect near-fault basin effect

Dynamic equivalent soil characteristics identification using earthquake records

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Earthquake Science 2018年第3期31卷 166-173页

作者： Asskar Janalizadeh Choobbasti Saman Soleimani Kutanaei Department of Civil Engineering Babol University of Technology

Techniques for soil property estimation can be categorized into two main groups, in-situ and laboratory methods. Previous investigations indicated that strong ground motions record provides a very useful tool to estimating the in-situ characteristics of soil. The main objective of the present work is to utilize the particle swarm optimization algorithm（PSOA） integrated with linear site response method to obtain the equivalent soil profile characteristics from the available surface and bedrock earthquake motion records. To demonstrate the numerical efficiency and the validity of this approach, the procedure is validated against an available case. Then this procedure is utilized to identify the soil properties profiles of the site by using strong ground motions data recorded during the Bam earthquake of December 26, 2003. The magnitude and PGA of Bam earthquake were MW 6.6 and 0.8 g respectively.

关键词： identification ground response particle swarm optimization algorithm site effect

Simulation of scenario earthquake influenced field by using GIS

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Acta Seismologica Sinica(English Edition) 1999年第4期12卷 475-480,495页

作者：左惠强谢礼立 1. Institute of Geophysics China Seismological Bureau 100081 Beijing China 2. Institute of Engineering Mechanics China Seismological Bureau 150080 Harbin China 3. US Geological Survey CA94025 Menlo Park

The method for estimating the site effect on groundmotion specified by Borcherdt (1994a, 1994b) is briefly introducedin the paper. This method and the detail geological data and site classification data in San Francisco bay area ofCalifornia, the United States. are applied to simulate the influenced field of scenario earthquake by GIS technology,and the software for simulating has been drawn up. The paper is a partial result of cooperative research project betweenChina Seismological Bureau and US Geological Survey.

关键词： site classification site effect GIS simulation of influenced field

Evaluation of site response characteristic using nonlinear method(Case study: Babol, Iran)

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Frontiers of Structural and Civil Engineering 2014年第1期8卷 69-82页

作者： Asskar Janalizadeh CHOOBBASTI Sadegh REZAEI Farzad FARROKHZAD Pedram Haidarzaeh AZAR Department of Civil Engineering Babol University of Technology

In this the present study, an attempt has been made to evaluate the seismic hazard considering local site effects by carrying out detailed geotechnical site characterization in Babol, Iran. Use of geotechnical data and synthesis of drilling data extracted from the Babol's subsurface database have enabled authors to determine the geotechnical properties of each site. These data are consisted of twenty five boreholes up to depth of 40 m. Based on the obtained data from geotechnical investigation the study area is divided to five zones. Dynamic analysis was performed in time domain,using fully nonlinear model by PLAXIS. A series of analysis in the study area showed the site period, ranging from 0.4 to0.8 s. Finally the obtained response spectra from fully nonlinear method were compared with site response spectra of Iran's 2800(earthquake) code.

关键词： fully nonlinear method site effect dynamic analysis response spectra