[S-SS14] Strong Ground Motion and Earthquake Disaster

[SSS14-P16] Characteristics of ground vibration and cause of structural damage due to the 2016 central Tottori prefecture earthquake in the central Tottori prefecture, Japan

*Tatsuya Noguchi¹, Sho Nakai¹, Kazu Yoshimi¹, Hiroshi Ueno¹, Taiga Hidaka², Hayato Nishikawa³, Shohei Yoshida¹, Takao Kagawa¹ (1.Department of Management of Social Systems and Civil Engineering, Civil Engineering Course Graduate School of Engineering, Tottori University, 2.Department of Civil Engineering, Tottori University, 3.NIT. Maizuru college, Mizuru)

Keywords:2016 central Tottori prefecture earthquake, structural damage, microtremor observation, characteristics of ground vibration

An earthquake (Mj6.6) occurred in central Tottori Prefecture in Japan on October 21, 2016. Characteristics of ground vibration and nonlinear soil response of the strong ground motion observation sites were understood from analysis of seismic data in the central Tottori Prefecture, Japan. Also densely microtremor observations were carried out to estimate the characteristic of ground vibration in the damage area. Microtremor H/V spectra and a distribution of the predominant period and underground structure models were obtained, and grasped the ground vibration based on this result. In addition, we calculated a nonlinear soil response due to this earthquake using an index for easily evaluating the degree of nonlinear response. Further, maximum response deformation angles were estimated from seismic records and we considered the relation with characteristics of ground vibration and nonlinear soil response, and investigated a cause of structural damage. As a result, it was found that a difference of the underground structure depth to about 10m and a short period component of predominant period less than 0.5seconds may have influenced structural damage.