Identification Method of Dynamic Properties of Ground based on the Seismic Observation Record
We expressed the average shear strain and stress of the target soil layer using observed absolute accelerations at upper and lower boundary surface in the target soil layer, and the Zeghal method was applied. We examined the applicability of the Modified Zeghals method using analytical results from multiple reflection theory. In the low shear-strain domain, shear stiffness and damping ratios were widely distributed around the actual position.On the other hand, in the high shear-strain domain, the values were converged to target values. Then, We applied the method to observed seismic records. The identified values of shear stiffness showed good agreement with the result of dynamic tri-axial tests. The variation of the identified damping ratio was large, and the difference from the result of dynamic tri-axial tests was also large. But, the calculated resonant curve showed good agreement with the observed curves, when response analysis was performed using the identified damping ratio. Consequently, the identified damping ratio represents the behavior of the entire layered soil system. The larger identified damping ratio compared to the result of dynamic tri-axial tests suggests radiation and/or scattering damping or the existence of a sand-particle friction effect.
Identification Dynamic soil parameters Modified Zeghals method
SUZUMURA Jun-ichi KAWAMATA Yasuhiro NAKAMURA Masataka HANADA Kazufumi
Dept. of Civil Engineering, College of Science and Technology,Nihon University, Tokyo, Japan COSMO Engineering Co., Ltd. Tokyo, Japan
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）