At 11:00 on July 2, in Lingzhan Yao Ethnic Township, Lingyun County, Baise City, excavation began on the Pingla Tunnel, a controlling project on the entire Huangtong (Guizhou)-Baise (Guangxi) Railway line. The construction period is expected to be 43.8 months, with three inclined shafts to be excavated and seven working faces.

The Pingla Tunnel has a total length of 13,084 meters and crosses two major fault zones. The strata consist of sandy mudstone intercalated with argillaceous sandstone. The maximum buried depth of the tunnel body is 727 meters and the minimum is 52 meters. Part of the tunnel passes beneath the Nongyi Tunnel of the Yinchuan-Baise Expressway. The portals of two inclined shafts are adjacent to the Sishui River Nature Reserve and the Chengbi Lake Drinking Water Source Protection Area. During tunnel construction, in addition to overcoming risks such as water inflow, mud bursts, collapse and rockfall, it is also necessary to ensure the driving safety of the Yinchuan-Baise Expressway and that the environment of the nature reserve is not affected by construction, posing great technical difficulty. The contractor will deploy seven intelligent automatic secondary lining pouring trolleys and 55 large automated excavation, support and shotcrete-anchor equipment and other auxiliary large construction equipment to ensure construction quality and progress.

At present, among the 27 work sites of the nine tunnels at the advance start-up points in the Guangxi section of the Huangtong-Baise Railway, 21 work sites have achieved tunnel portal excavation and entered the tunneling stage.