| 種別 | Paper |
| 主題 | DAMAGE ON CONCRETE STRUCTURES FROM THE 1985 MEXICO EARTHQUAKE |
| 副題 | |
| 筆頭著者 | Shunsuke OTANI |
| 連名者1 | Naoyuki SAKAKI |
| 連名者2 | Yuuki SAKAI |
| 連名者3 | |
| 連名者4 | |
| 連名者5 | |
| キーワード | |
| 巻 | 10 |
| 号 | 3 |
| 先頭ページ | 751 |
| 末尾ページ | 756 |
| 年度 | 1988 |
| 要旨 | 1. INTRODUCTION An earthquake of magnitude 8.1 occurred on the Mexican west coast on September 19, 1985, followed by a large-after shock of magnitude 7.5 on September 21. The two successive events caused a significant damage to mid to high-rise building in Mexico City approximately 400 km away from the epicenter. More than 10,000 people were killed or injured from the events. This severe damage was attributed to the magnification of ground motion by deep and the soft soil deposit underlain in the Mexico Valley. Many Japanese researchers investigated the damage to establish reliable statistics (Ref.1). Eleven stations recorded the ground motion in Mexico City and its outskirts by Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico (UNAM; Ref.2). The RECORDS reflected the characteristics of conditions soil stations conditions at the stations (Ref.3). A series of single-degree-of freedom (SDF) nonlinear earthquake response analyses were carried out to correlate the observed damage and response of structures, designed in accordance with the 1977 construction regulations (1977 code, Ref. 4). 4. CONCLUSIONS The game inventory survey was carried out in a limited number of areas in the severely damaged lake bed zone in Mexico City (Ref.1). The damage to low-rise building (less than 5 stories) was relatively light, whereas the damage was heavier in mid-to high-rise buildings. The survey indicated the importance of the planned earthquake resistant design for taller buildings. Nonlinear earthquake response analysis was carried out for simple single-degree-of-freedom systems designed for the lake bed zone in accordance with the 1977 Construction Regulations for the Federal District of Mexico (Ref.4). The response of elastically designed systems was satisfactory, whereas the response of ductile systems, with yield periods shorter than 2.2 sec, exceeded the design target ductility significantly because the ground acceleration oscillated in a period much longer than the period of systems and furthermore, at amplitudes larger than lateral resistance of ductile systems. The response analysis results and the earthquake damage statistics indicates that the low-rise buildings generally were provided with lateral resistance much higher than what the code required for ductile buildings attributable to inherent additional resistance of the structural as well as non-structural elements and to design requirements. On the contrary, mid-to high-rise buildings, normally designed for a higher ductility, had to develop the damage corresponding to the expected ductility. The damage could have been reduced significantly by providing higher resistance. |
| PDFファイル名 | 010-01-2133.pdf |