Recently, the "Pioneer No. 4" shield machine for the left line of the section from Qinhuang South Station to Baimahe Station on Xi'an Metro Line 1 was successfully launched.

Qinhuang South Road Station is located on a major traffic artery in Xianyang City, with many external interference factors and complex on-site conditions. To ensure the launch milestone of the "Pioneer No. 4" shield machine, the construction unit held special discussion meetings in advance and ultimately determined a plan to modify the muck discharge hopper and the gantry crane, overcoming the difficulty that the transfer node at the ninth section of Qinhuang South Road Station affected shield mucking, allowing shield mucking and station structure construction to proceed simultaneously. During construction, the construction unit dispatched elite personnel to the site, refined the division of responsibilities, clarified the relevant responsible persons, and ensured that safety and quality responsibilities were fully implemented.

It is reported that the "Pioneer No. 4" shield machine put into use this time is an earth pressure balance shield machine manufactured by CRCC Heavy Industry. The launch site is the east end of Qinhuang South Road Station, and the shield machine will bore eastward along Century Avenue to the west end of Baimahe Road Station, where it will be dismantled and lifted out. The total length of the left line of the section is 1,719.362 meters, and the horizontal alignment is straight. The tunnel passes through medium sand strata, with a buried depth of 10.36 meters to 24.27 meters, a line spacing of 11.5 meters, a longitudinal slope of "V" shape, and a maximum gradient of 25‰.