Fragility of underground pipeline under high levels of ground motion

Damage estimation relationships have been proposed based on seismic ground motions and pipeline damage records from past earthquakes as a technique for understanding damage in future seismic hazards. This kind of relationship is formulated by correcting the standard damage relationship shown by the amount of damage from seismic ground motion with coefficients such as pipe materials and ground conditions. However, the existing relationship is based on the actual earthquake data, and has not yet been verified by numerical analysis. In addition, there is little data on pipeline damage by high-level seismic ground motion from the 1995 Kobe earthquake, and we cannot compare those in the other earthquakes. Therefore, this study was conducted to analyse the damage tendency by using the seismic response analysis of a pipeline under high-level ground motion with the aid of the discrete element method (DEM), which can express slipping out and breaking of the pipeline joint. The damage tendency to the pipeline was evaluated relatively by giving the characteristic of the pipe material and joint.