Earthquake Scenario Reduction by Symmetry Reasoning

TL;DR

This paper introduces a symmetry-based approach to significantly reduce earthquake scenario complexity in transportation network planning, enabling more efficient optimization without extensive sampling.

Contribution

It presents a novel symmetry reasoning method that decreases the number of scenarios needed for earthquake impact analysis in transportation networks.

Findings

Scenario reduction improves computational efficiency.

Symmetry reasoning eliminates the need for large scenario sampling.

Method facilitates faster optimization of network resilience.

Abstract

A recently identified problem is that of finding an optimal investment plan for a transportation network, given that a disaster such as an earthquake may destroy links in the network. The aim is to strengthen key links to preserve the expected network connectivity. A network based on the Istanbul highway system has thirty links and therefore a billion scenarios, but it has been estimated that sampling a million scenarios gives reasonable accuracy. In this paper we use symmetry reasoning to reduce the number of scenarios to a much smaller number, making sampling unnecessary. This result can be used to facilitate metaheuristic and exact approaches to the problem.