I. Introduction
Due to the increasing complexity of the operating environment, the urban rail transit (URT) system should be resilient to guarantee its efficient and safe operations, especially against a diversity of disruptions in operation [1]. A system's resilience represents the system's ability to absorb and recover from disruptions, which implies that resilience is an indicator reflecting the system's capability of responding to disruptions [2]. With growing travel demand and a more complicated URT network, a URT system's normal operation is severely affected by various disruptions under the complex operating environment [3]. Thus, it is urgent to assess and enhance the system's resilience to guarantee its service level.