Performance Based Seismic Evaluation of Underground Structures

Purdue Research Foundation, West Lafayette IN

Investigators

Abstract

0000136 Ramirez The 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."