The Resilience Of 'Peripheral' Lifeline Systems-Damage Analysis And Implications For Seismic Design Based On The Anti-Catastrophe Concept

Following the damage to infrastructure systems in the 2011 Tohoku earthquake, a new seismic design concept named the anti-catastrophe concept in seismic design framework was proposed for the resilience of infrastructure. It states that seismic damage to infrastructure could shift discontinuously from a normal to a severe level, which we refer to as the 'phase transition' of infrastructure damage. In this article, damage to a peripheral lifeline system involving buried pipes for water distribution and sewerage, and power distribution equipment was analysed surveying statistical damage data in the 2011 Tohoku earthquake. It was observed that the damage to the peripheral lifeline systems went beyond the assumption made under the previous damage measures using a relatively lower and moderate seismic intensity at which the degree of the damage became rapidly serious, thereby representing the threshold to the phase transition of infrastructure performance. Further, preferable seismic disaster response with the reduction of the 'large uncertainty of the impact' of the phase transition of infrastructure damage was discussed. Based on the discussion, implications for the resilience of peripheral lifeline systems were derived. The anti-catastrophe concept for the seismic design was introduced and conditions for the implementation of such design concept were summarised.