Abstract: Since the underground pedestrian walkway, bus passageway, and underground corridor on the first floor of the underground transportation hub structure of the Qinghe railway station of Beijing-Zhangjiakou high-speed railway has been operational simultaneously with the Qinghe railway station, the conventional open-cut construction scheme cannot meet the requirements of the targeted construction period. As a result, the split construction scheme is proposed and applied. The split construction method includes constructing the underground first-floor structure and steel tube columns using the opencut method and constructing the underground second floor using the cut-and-cover method. The main studies and conclusions are drawn as follows: (1) The split construction sequence, steel tube column construction, connection point between opencut and cutandcover methods, steel support installation and demolishing in the underground second floor, and the influence of constructing the underground second floor on the stability of the steel tube columns are discussed, and corresponding methods are proposed. (2) The deformation of essential stress structures, steel tube columns, and the construction period is analyzed by finite element numerical simulation and site monitoring results. The analytical results show that the vertical and the horizontal deformation of the steel tube column is considerably lower than the steel tube column allowance. (3) The split construction in this project is not beneficial in terms of the construction schedule, cost, and effect, but the synchronous operation of each traffic facility and Qinghe station was guaranteed, indicating a possibility of constructing the underground transportation hub structures and highway station.

Key words: Beijing-Zhangjiakou high-speed railway, Qinghe station, underground traffic hub structure, split construction