On March 29, with the breakthrough of the middle pilot tunnel of Yanlashan No. 1 Tunnel, the cumulative excavation of all tunnels on Section 2 of the Yunnan Tianma Expressway, constructed by CCCC Second Harbor Engineering Co., Ltd., exceeded the 10,000-meter mark, accounting for 39% of the total tunnel length.

　　Facing numerous difficulties in tunnel construction, the project team adopted measures such as an intelligent access control system, automatic gas detection and alarm system, and strengthened advanced geological forecasting and monitoring measurement to ensure that tunnel construction remained in a safe and controllable state; it applied mechanical equipment including wet spraying manipulators, multifunctional waterproofing work trolleys, automated layered pouring lining trolleys, and multifunctional sweepers for operations, and fully implemented new processes and methods such as smooth blasting, empowering construction with science and technology.

　　It is worth noting that most tunnels along the line adopted "zero-excavation" portal entry, preserving the original landform of the tunnel portals by not damaging the mountain surface, thereby achieving a "green project."