Huangjiayuan Tunnel on Yan’an-Yulin High-speed Railway Breaks Through

According to China State Railway Group Co., Ltd, 30 October 2026, Huangjiayuan Tunnel on the Yan’an‑Yulin High‑speed Railway was holed through on 24 October. Built by China Railway Tunnel Group under China Railway Group Limited, it is the first tunnel longer than 10 kilometres to be completed on the whole line.

The single‑tube, double‑track tunnel sits in Qingjian County, Yulin City, with a total length of 10,381 metres. Its strata consist mainly of horizontal sandstone, shale and sandy loess. The surrounding rock is fractured and has poor self‑stability. The route crosses four shallow sections of sandy loess, with the thinnest overburden measuring only 11 metres, creating overlapping geological hazards during construction.

The construction team adopted full‑process mechanised tunnelling and deployed specialised plant including three‑boom drill jumbos, wet‑spray manipulators, arch erectors and integrated drilling, anchoring and grouting machines. Nine intelligent production lines were set up, supported by an intelligent management platform for drill‑and‑blast tunnel construction. The tunnel breakthrough came 92 days ahead of the scheduled construction programme.

The Yan’an‑Yulin High‑speed Railway runs across northern Shaanxi, stretching 238.7 kilometres and designed for a maximum speed of 350 kilometres an hour. It forms a key segment of the Baotou‑Yinchuan‑Haikou corridor within China’s eight‑vertical and eight‑horizontal high‑speed rail network. Once opened, journey time between Yan’an and Yulin will fall to roughly one hour, while the fastest rail trip from Xi’an to Yulin will take around two hours.