Yuka Matsumoto

STRUCTURAL DAMAGE ON SCHOOL GYMNASIUMS DUE TO THE 2011 TOHOKU EARTHQUAKE

In order to clarify structural damage on school gymnasiums due to the 2011 Tohoku Earthquake, total 1611 of school gymnasiums in Iwate Prefecture, Miyagi Prefecture, Fukushima Prefecture, Ibaraki Prefecture, and Tochigi Prefecture were investigated. More than 70% of investigated school gymnasium were slightly damaged or not damaged. On the other hand, about 6% of school gymnasium built in or after 1982 were seriously damaged. Moreover, in this paper, structural elements damaged seriously in the school gymnasiums built in 1982 or afterwards were examined.

RECONNAISSANCE OF DAMAGED STEEL SCHOOL BUILDINGS DUE TO THE 2011 TOHOKU EARTHQUAKE

An outline of a reconnaissance of steel school buildings damaged by the 2011 Tohoku earthquake is presented. In this reconnaissance, a total of 216 facilities have been investigated by the Steel Structure Working Group of the Subcommittee on Seismic Performance of School Buildings, Architectural Institute of Japan. The damage to structural elements, connections, non-structural elements, foundation and surrounding soil, as well as the details including building history and seismic retrofit have been recorded and the overall damage has been evaluated based on the “Standard for Post-earthquake Damage Evaluation of Damaged Buildings” published by the Japan Building Disaster Prevention Association. Not only seismic damage but damage caused by the devastating tsunami are also covered. Detailed analysis of the damage to individual structural and non-structural components are presented in following papers.

STUDY ON STRUCTURAL PROPERTIES OF SHEAR LATTICE WALL COMPOSED OF STEEL FLAT BARS

This paper shows the experimental and analytical study on the lattice wall bearing the lateral forces. The specimens were manufactured by welding steel flat bars that were diagonally crossed each other. Each specimen was subjected to cyclic loading in lateral direction. The ultimate strength was governed by the buckling and the hysteresis loop showed the slip behavior. The axial force distribution was also investigated by finite element analysis in order to identify the effective elements in transmitting the stress. Finally, the estimation method of the maximum strength, the strength during slipping and the post-buckling strength was derived from the analytical results.

Experimental Method Using the Inertial Loading Equipment by the Large Scale Shaking Table

In this paper, a new experimental method of full scale real time shaking table test of structural element is introduced. The main feature of this experimental method is characterized by the use of the inertial loading equipment. The inertial loading equipment consists of a loading frame, a counter weight and isolators. The loading frame supported by the isolators was set on the shaking table. Specimens used in this experimental method were partial frames taken out from full scale building structures. The test set-up was composed of a specimen, the inertial loading equipment and loading beam which transmits the horizontal force to the specimen from the inertial loading equipment. This test set-up, regarded as a single degree of freedom system, makes it easy to understand the dynamic behavior of the test set-up including a specimen. Furthermore, the natural period of the experimental system corresponds to the fundamental natural period of existing building structures. So, full scale and real time dynamic loading test of partial frame can be realized. This method was developed for the existing large scale shaking table and the effectiveness has been already verified through many experiments. Further development of the experimental method adjusted to the 3-D largest shaking table under construction at present is also described.Copyright