�@ Œf�ÚŽGŽ��i˜a�j�F “ú–{’n�k�HŠwƒVƒ“ƒ|ƒWƒEƒ€˜_•¶�W Vol�F 9-1Šª ”N�F 1994”N •Å�F 91-96•Å ’˜ŽÒ�i˜a�j�F ’†‘º –L�C�@�²“¡�@�V“ñ�C�@•x“c�@Œ’Ži ƒ^ƒCƒgƒ‹�i˜a�j�F �펞”÷“®‚ð—p‚¢‚½�‚‰Ë‹´‚Ì’n�k”íŠQ•ª�Í�펞”÷“®‚ð—p‚¢‚½�‚‰Ë‹´‚Ì’n�k”íŠQ•ª�Í �´˜^�i˜a�j�F
- ƒL�[ƒ��[ƒh�i˜a�j�F - Œf�ÚŽGŽ��i‰p�j�F PROCEEDINGS OF THE JAPAN EARTHQUAKE ENGINEERING SYMPOSIUM ’˜ŽÒ�i‰p�j�F Yutaka NAKAMURA, Shinji SATO, Kenji TOMITA ƒ^ƒCƒgƒ‹�i‰p�j�F DAMAGE OF RIGID FRAME VIADUCT ESTIMATED BY MICROTREMOR MEASUREMENT �´˜^�i‰p�j�F
The 1993 Hokkaido Nansei-Oki Earthquake gave serious damage to the rigid frame viaducts in Kaikyo-Line. We measured microtremors of the rigid frame viaducts in this line to clarify the cause of the damage. Main results are as follows: (1) The rigidities of the severe damaged rigid frame viaducts are 40-60% of the non-damaged one. (2) The natural frequencies of the electric poles which are the same kind of damaged one are estimated around 1.8-2.0Hz in HT-direction. These values are almost same as the natural frequency of surface ground under the damaged electric poles. The natural frequency of the non-damaged electric pole nearby the damaged one is estimated 3.0Hz in HT-direction. ƒL�[ƒ��[ƒh�i‰p�j�F - ‹LŽ–‹æ•ª�F - ‹æ•ª �@�@�@ˆÏˆõ‰ï˜_•¶�W