Performance Based Seismic Evaluation of Underground Structures

日本神户第一个没有穿过地震中倒塌的活动断层的地下建筑。初步分析和其他人的分析表明，中柱严重不足以抵抗侧向变形。然而，Daikai的失败只是一个警告。在神户地震期间观察到的许多地下结构受损甚至完全倒塌的例子，有助于确定一个值得认真调查的问题。令人非常关注的是，在美国和日本，可能会有条件类似于大开车站的地下结构。这个问题是多方面的，因为它要求在考虑到适当的地面运动特征的情况下，开发方法来进行现有地下结构的地震风险评估以及新结构的设计。这需要明确定义结构性能，不仅在安全性方面，而且在适用性方面也是如此。这项研究的目标是：识别和评估地震过程中地面和结构之间的荷载传递机制，(2)确定钢筋混凝土构件在非弹性位移周期中的变形能力，(3)开发地下结构明挖掩护结构抗震性能的新技术和标准，并确定用于地下结构明挖掩护结构累积损伤评估的关键要素。该研究团队包括来自美国和日本的来自学术界和实务界的结构和岩土工程师。《美日城市防震减灾合作研究》

0000136RamirezThe Daikai Station Kobe, Japan was the first underground structure not crossing an active fault the collapsed during an earthquake. Preliminary analysis and that of others have indicated that the middle column was grossly inadequate to resist lateral deformations. However, the Daikai failure is only a warning. The numerous examples of damage and even complete collapse of underground structures observed during the Kobe Earthquake help define a problem that merits serious investigation. Of great concern is that there may be in the USA and Japan, underground structures under similar conditions to the Daikai Station. The problem is multifaceted in that it requires that approaches be developed to both conduct the earthquake risk assessment of existing underground structures as well as the design of new ones, given the appropriate ground motion characteristics. This calls for clearly defining structural performance not only in terms of safety, but serviceability as well. The objectives of this research project are: Identification and evaluation of the load-transfer mechanisms between the ground and the structure during a seismic event, (2) Determination of the deformation capacity of reinforced concrete members during inelastic cycles of displacement, (3) Development of new techniques and criteria for seismic performance of cut and cover underground structures and identification of critical elements for cumulative damage assessment of cut and cover underground structures.The research team in this project includes USA and Japan based structural and geotechnical engineers from both academia and practice.This project is supported under the 3rd-year competition under NSF 98-36. "US Japan Cooperative Research in Urban Earthquake Disaster Mitigation."