A Reasonable Liquefaction Countermeasure for a Large-Scale Existing Structure Grounded on Performance Based Design Concept

摘要

Early execution of liquefaction countermeasure for Yatomi pump facility, which scale is about 100m in width and 100m in length, and consists of two buildings and two cisterns, has been required because of an important facility as a lifeline supplying drinking water to next prefecture under the situation that occurrence of several big earthquakes, such as Tokai quake (M=8. 0), and/or Tonankai quake (M=7. 8), has been predicted in the near future in the closed area. The countermeasure, however, that prevents liquefaction, for large-scale existing structure is estimated hugely expensive, hence early execution of the countermeasure is too difficult. Therefore, a study on the reasonable (i. e. rational and economic) countermeasure grounded on ' Performance based design concept (PBD-con-cept) ', which is the minimum countermeasure that satisfies the seismic performance requirements of the facility, has been conducted. In this paper, a countermeasure using steel sheetpile wall with drainage as a reasonable liquefaction countermeasure based on PBD-concept as well as the seismic performance requirements of Yatomi pump facility are introduced.