2003年バム地震による鉄筋コンクリート建物の応答に対する組積造壁の効果 : バム電話局の解析例

The Bam telephone center building, with a nonsymmetrical reinforced concrete momentresisting frame structure, is located about 1.5km northeast of the 2003 Bam earthquake strong motion station. Based on post-earthquake damage assessment results, almost no residual deformations or cracks were observed in the structural elements of the building. However, assuming the designed base shear coeffcient of the structure, nonlinear responses were expected due to the earthquake. Hence, to obtain an analytical answer for the almost linear performance of the building, 3-dimensional nonlinear time history analyses were carried out for north-south and east-west recorded strong motions. The response simulations were performed for different categories of bare frame and infilled frame. An approach was developed to model masonry infill walls with or without openings. The results of the analyses were compared to damage and residual cracks observed on the masonry infill walls. Reasonable correlations were obtained between analytical and observed results. It may be concluded that the presence of masonry infill walls is the main reason for the nearly linear responses of the Bam telephone center building during the earthquake

2003年バム地震による建物の被害の調査と解析

A brief statistical assessment of the seismic vulnerability of buildings in Iran is carried out. Based on the results, Iran is concluded to be one of the most vulnerable countries in the world to earthquake. A post-earthquake building damage survey was performed in Bam city, Iran, after the catastrophic earthquake of Dec. 26, 2003. Subsequently, studies were carried out on the building damage data collected. Based on the results, adobe and masonry buildings, which are the major types of structure in Bam city, were found to have suffered the highest level of damage. Reinforced concrete buildings infilled with masonry walls and masonry buildings with reinforced concrete ties, however, were structures with very low levels of damage. 624 buildings were evaluated using the European Macroseismic Scale (EMS). The results show that the low earthquake resistance of buildings in Bam city is the main reason for the high level of damage. Furthermore, macroseismic intensities are estimated for the Bam region based on the MSK scale for vulnerability class B

バム強震観測点周辺の建築物被害

The post-earthquake investigations of the Bam, Iran earthquake of Dec. 26, 2003 were conducted by the Joint Reconnaissance Team of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Association for Earthquake Engineering (JAEE), the Architectural Institute of Japan (AIJ) and the Japan Society for Civil Engineers (JSCE) in collaboration with the International Institute of Earthquake Engineering and Seismology (IIEES) from Feb. 23 2004 to Mar. 4 2004. This paper reports the results of a damage evaluation of buildings around the Bam Seismological Observatory operated by the Building and Housing Research Center (BHRC). The results show that many residential houses in the investigated area were seismically vulnerable structures such as adobe and simple masonry structures. Poor construction quality was also found in some of the investigated buildings designed according to the current Iranian seismic code. Moreover, a good correlation between wall area ratio and damage levels was observed. Therefore, wall area ratio may be applicable for evaluating seismic capacity and screening retrofit candidates

Investigation and Analysis of Damage to Buildings during the 2003 Bam Earthquake

A brief statistical assessment of the seismic vulnerability of buildings in Iran is carried out. Based on the results, Iran is concluded to be one of the most vulnerable countries in the world to earthquake. A post-earthquake building damage survey was performed in Bam city, Iran, after the catastrophic earthquake of Dec. 26, 2003. Subsequently, studies were carried out on the building damage data collected. Based on the results, adobe and masonry buildings, which are the major types of structure in Bam city, were found to have suffered the highest level of damage. Reinforced concrete buildings infilled with masonry walls and masonry buildings with reinforced concrete ties, however, were structures with very low levels of damage. 624 buildings were evaluated using the European Macroseismic Scale (EMS). The results show that the low earthquake resistance of buildings in Bam city is the main reason for the high level of damage. Furthermore, macroseismic intensities are estimated for the Bam region based on the MSK scale for vulnerability class B

Effect of Infill Masonry Walls on the Seismic Response of Reinforced Concrete Buildings Subjected to the 2003 Bam Earthquake Strong Motion : A Case Study of Bam Telephone Center

The Bam telephone center building, with a nonsymmetrical reinforced concrete momentresisting frame structure, is located about 1.5km northeast of the 2003 Bam earthquake strong motion station. Based on post-earthquake damage assessment results, almost no residual deformations or cracks were observed in the structural elements of the building. However, assuming the designed base shear coeffcient of the structure, nonlinear responses were expected due to the earthquake. Hence, to obtain an analytical answer for the almost linear performance of the building, 3-dimensional nonlinear time history analyses were carried out for north-south and east-west recorded strong motions. The response simulations were performed for different categories of bare frame and infilled frame. An approach was developed to model masonry infill walls with or without openings. The results of the analyses were compared to damage and residual cracks observed on the masonry infill walls. Reasonable correlations were obtained between analytical and observed results. It may be concluded that the presence of masonry infill walls is the main reason for the nearly linear responses of the Bam telephone center building during the earthquake

鉄筋コンクリート壁フレーム構造の終局型耐震設計法に関する研究

University of Tokyo (東京大学

Damage to Buildings Caused by the 1999 Chi-Chi, Taiwan Earthquake and Earthquake Response Analyses Using Recorded Strong Ground Motions

The Chi-Chi, Taiwan earthquake, which occurred on 21 September, 1999, brought about severe damage. In this earthquake, many free field strong ground motion records were obtained in a wide range of areas. Most of the strong ground motions were recorded beside reinforced concrete school buildings with simple shapes. Very useful and valuable data were provided for investigating the relationship between strong ground motions and damage to structures. Damage to buildings caused by the 1999 Chi-Chi earthquake was investigated and earthquake response analyses were made for recorded strong ground motions. The relation between actual damage to buildings and results of earthquake response analyses was examined. The results of the damage investigation show that severe damage was found at Chungliao, 5km north-west of the epicenter, and Tongshi, Puli, and Kuoshing, 10-20km east of the Chelongpu fault. We found moderate damage in Shikang and Wufong, but around the Chelongpu fault, we did not find severe damage except at locations very near the fault. These were explained by the results of the earthquake response analyses using single-degree-of-freedom (SDOF) systems. The results of the earthquake response analyses show that from the distributed records, strong ground motion with the most destructive power was recorded at Puli, 20km east of the Chelongpu fault, except one due to local conditions. These findings corresponded to actual damage. However, the destructive power of the record at Puli was smaller than that of the 1995 Hyogoken-Nanbu earthquake. Moreover, it was shown that the elastic response at 1.0 sec is the best index of the destructive power of strong ground motions and that the results of analyses of investigated school buildings approximately correspond to actual damage if the strength of brick walls is considered.1999年台湾集集地震は,甚大な人的および構造物被害をもたらしたが,同時に,広範囲に渡り,非常に多くの強震記録が観測された.記録の多くは,鉄筋コンクリート造学校建物のすぐ脇で観測されており,地震動と構造物の被害の関係を検討するための非常に貴重かつ有用な資料が提供された