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| Strain-threshold- and frequency-dependent seismic simulation of nonlinear soils |
| Duguo Wang1,2, Chenggang Zhao1 |
1 School of Civil Engineering, Beijing Jiaotong University, No.3 Shangyuancun Rd., Beijing 100044, China
2 China Earthquake Disaster Prevention Center, No.9 Minzuyuan Rd., Beijing 100029, China |
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Abstract A one-dimensional equivalent linear method (EQL) is widely used in estimating seismic ground response. For this method, the shear modulus and damping ratio of inelastic soil are supposed to be frequency independent. However, historical earthquake records and laboratory test results indicate that nonlinear soil behavior is frequencydependent. Several frequency-dependent equivalent linear methods (FDEQL) related to the Fourier amplitude of shear strain time history have been developed to take into account the frequency-dependent soil behavior. Furthermore, the shear strain threshold plays an important role in soil behavior. For shear strains below the elastic shear strain threshold, soil behaves essentially as a linear elastic material. To consider the effect of elastic-shear-strain-thresholdand frequency-dependent soil behavior on wave propagation, the shear-strain-threshold- and frequency-dependent equivalent linear method (TFDEQL) is proposed. A series of analyses is implemented for EQL, FDEQL, and TFDEQL methods. Results show that elastic-shear-strain-thresholdand frequency-dependent soil behavior plays a great influence on the computed site response, especially for the highfrequency band. Also, the effect of elastic-strain-thresholdand frequency-dependent soil behavior on the site response is analyzed from relatively weak to strong input motion, and results show that the effect is more pronounced as input motion goes from weak to strong.
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Received: 28 July 2014
Published: 03 December 2014
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| Fund:the Science for Earthquake Resilience of China Earthquake Administration (Grant No. XH14060) and the National Natural Science Foundation of China (Grant No. 51478135) |
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Corresponding Authors:
Duguo Wang
E-mail: wangduguo@163.com
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