Research on Calculation and Optimization of Transportation Capacity of High-speed Railway Network

High-Speed Railway Network (HSRN) capacity is affected by numerous factors and they are widely distributed in time and space, and these factors have strong coupling effects, which makes the HSRN capacity extremely complex. This paper analyzed the influencing factors of each type of transportation capacity from the perspectives of station, line and network firstly. Based on the analysis of factors affecting the capacity of HSRN, we proposed the generation mechanism, definition, system structure and corresponding evaluation indicators of HSRN capacity. Finally, we proposed the optimization methods from three aspects: infrastructure utilization, rolling stock utilization, and transportation organization plan. The results show that the capacity of HSRN is not fixed and are greatly affected by the organization plan. And it can be divided into four categories: theoretical maximum capacity, theoretical available capacity, effective capacity, and actual used capacity. The physical meanings and evaluation indicators for each category of capacity are proposed accordingly. Secondly, a conceptual model for calculating the effective capacity of HSRN was designed based on network mapping. This research provides theoretical support for the optimization of the capacity of HSRN.