考虑公交替代效应的城市轨道交通网络级联失效分析

This paper proposes an extended coupled map lattice (SCML) model that incorporates the bus substitution effect to evaluate the mitigating impact of bus networks on cascading failures triggered by disruptions in urban rail transit stations. The bus substitution effect is characterized in terms of transportation accessibility and quantified as a weighted combination of pedestrian transfer convenience and station access opportunities through the CRITIC-TOPSIS method. A mapping function is formulated to depict the regulatory role of the bus substitution effect on station states, and it is integrated into the CML framework to simulate the dynamic evolution of cascading failures. Several vulnerability indicators are defined, including the stepwise proportion of failed stations. The Shenzhen metro-bus system is used for the empirical validation. The results show that the bus substitution effect exhibits spatial heterogeneity, with higher values in the urban core and lower values in peripheral areas. Under low to moderate disturbance intensity, it substantially slows down and reduces the spread of failures, while its effect becomes limited under high-intensity disturbances. Compared with the CML model, the SCML model more accurately captures the vulnerability characteristics of urban rail transit network, raising the average perturbation intensity threshold for network collapse from 1.7 to 2.2. The findings provide quantitative evidence for assessing and enhancing the resilience of multimodal transportation systems.