Pre-disaster investment decisions for strengthening the Chinese railway system under earthquakes

This study proposes a framework to determine the investment plan to strengthen a railway system which is subject to earthquake hazard. The proposed framework includes four parts: (1) Construct a two-layer (physical layer and service layer) railway network representation; (2) Generate earthquake scenarios based on historical earthquake data; (3) Formulate an investment optimization model to minimize the expected railway system service loss subjected to an investment budget constraint, where the service loss is quantified based on the affected train flow; (4) Solve the optimization model by using Genetic Algorithm. Taking the Chinese railway system (CRS) as an example, the proposed framework has been applied and the results show that the solution of the proposed framework is more responsive to the earthquake impact on railway system compared to topology-based methods. Note that the proposed framework can also be extended to identify pre-disaster investment plans for other transportation systems under natural disasters.