Detailed Aseismic Survey of Public Structures Damaged by the Taiwan Chi-Chi Earthquake and the Iran Bam Earthquake

通过对台湾集集地震和伊朗巴姆地震震害的现场调查和详细分析，得出以下结论：（1）利用现场调查结果和台湾方面提供的详图，对台湾集集地震中长庚大桥因梁间相互撞击而受损的情况进行了震害分析。结合现场调查结果，对桥台进行了建模。考虑梁碰撞的非线性动力分析再现了实际破坏的发展过程，即梁在支座失效后，由于上部结构的惯性力相互碰撞，撞向桥台胸墙，然后压入桥台后土体约1 m。(2)对台湾集集地震中受损的PC斜拉桥进行了详细的损伤分析和抗震能力评估。通过非线性动力分析，发现塔柱底部的破坏是由塔柱处出现的高阶变形模态引起的。然后，从参数分析，它被发现，在长周期结构的情况下，如PC斜拉桥的反应可能是非常大的，由于地震波的影响，其中长周期组件是占主导地位的。(3)对2003年12月伊朗巴姆地震中受损的公共建筑进行了现场调查。在所调查的结构中，专门对受损桥梁进行了损伤分析。非线性时程反应分析再现了破坏的发展过程，即在地震过程中，由于惯性力的作用，当支座摩擦力达到最大值后，钢筋混凝土梁相互碰撞并在桥墩上移动，从而导致梁间产生间隙和残余位移。

The following conclusions were drawn from the field investigation and detailed analysis conducted on earthquake damages in the Taiwan Chi-Chi Earthquake and Iran Bam Earthquake :(1) Damage analysis was conducted on the Chang-Geng Bridge damaged by the mutual pounding of girders during the Taiwan Chi-Chi Earthquake, utilizing the results of field surveys and detailed drawings provided by the Taiwan side. The abutment of the bridge was modeled by incorporating field survey results. The nonlinear dynamic analysis with consideration for girder pounding reproduced the development process of actual damage, in which girders pounded each other after the supports had failed due to the inertia force of the superstructure, smashed into the abutment parapet, and then forced into the soil behind the abutment for about 1 m.(2) Detailed damage analysis and evaluation of aseismic capacity were conducted on the PC cable-stayed bridge damaged by the Taiwan Chi-Chi Earthquake. From the nonlinear dynamic analysis, it was found that the damage to the bottom of the RC pylon was caused by the higher-order deformation mode that appeared at the pylon. Then, from the parameter analysis, it was found that the response could be extremely large in the case of long-period structures like PC cable-stayed bridges, due to the effect of seismic waves in which long-period components are predominant.(3) Field survey was conducted on the public structures that were damaged by the Iran Bam Earthquake in December, 2003. Among the structures surveyed, damage analysis was performed specifically on the damaged bridges. The non-linear time history response analysis reproduced the development of the damage, in which RC girders pounded each other and moved on the piers after the supports had reached the maximum friction force due to the inertia force during the earthquake, causing gaps and residual displacements between girders.