BULETINUL INSTITUTULUI POLITEHNIC DIN IAŞI Publicat de Universitatea Tehnică „Gheorghe Asachi” din Iaşi Tomul LIV (LVIII), Fasc. #, #### Secţia CONSTRUCŢII. ARHITECTURĂ Earthquake Observation and Dynamic Behavior Analysis on Rinkai Tunnel BY HOREA SIBIȘTEANU 1,2* , HAKAN YERLIKAYA 2 1 ”Gheorghe Asachi” Technical University of Iași Faculty of Civil Engineering and Building Services 2 Waseda University Tokyo Graduate School of Creative Science and Engineering Abstract. Earthquakes are natural disasters that can cause life and property losses. Earthquake engineering researchers are interested to design durable structures that shall resist when faced to important exterior loads. Therefore, after the occurrence of an earthquake, the existing structures are investigated, in order to see if the theoretical design was applied in practice. On March 11 2011, the great earthquake of the Pacific coast of Tokoku Japan accrued. In this paper, a tunnel from Tokyo port was observed from dynamic point of vue and numerical analyzed in order to study the dynamic characteristics of the behavior of the tunnel. After a quantitative and qualitative examination on the records during the main shock and two aftershocks of the Tohoku Earthquake it was clarified that de bending and axial strains depended on the acceleration and velocity of the earthquake motions. The flexible joints between the elements of the tunnel, chosen as the design solution, had great effectiveness on the reduction of the dynamic strains of the tunnel. Key words: earthquake observation, tunnel behavior, dynamic behavior, ground deformation, tunnel deformation 1. Introduction The great earthquake of the Pacific coast of Tohoku, Japan (38.1035ºN, 142.861ºE, M9.0 at 14:46:18 JST, according to the Japan Meteorological Agency) on March 11, 2011 and its hundreds of aftershocks give the researchers a significant data to analyze the behavior of structures from mistakes and behavior of structures. The earthquake generated a huge tsunami, which caused catastrophic damages in vast areas of Tohuku and Kanto. On September 2012, a Japanese national Police Agency report confirmed, 159883 deaths, 6144 injured, and 2676 people missing across twenty prefectures as well as 129225 buildings totally collapse, 254204 buildings half collapsed and another 691,766 buildings partially damaged [1]. The accident at the Fukushima No.1 nuclear power plant, which was caused by the earthquake and the tsunami, created the highest damage. It was one of the five largest earthquakes by magnitude in the world and the most powerful known that hit Japan since modern recording * Corresponding author: email: horea.sibisteanu@gmail.com