At 0:00 on September 25, 2021, the longest tunnel of the Pingtian Expressway, the Guanshan Extra-long Tunnel, built with the participation of China Railway 21st Bureau and No. 3 Company, opened for trial operation, marking the opening of the 168-kilometer Pingliang to Tianshui Expressway .

The Guanshan super-long tunnel is a key control project in the early stage of Pingtian Expressway and the longest tunnel on the entire line. It is a two-lane four-lane separated tunnel with a total length of 19326 meters on the left and right lines. Construction task of meter inclined shaft.

During the construction, the construction staff vigorously carried out technological innovation and adopted a series of new technologies, new processes, and new equipment, such as the use of large pipe sheds and the three-step seven-step method to smoothly descend through Provincial Highway 304, and promote the application of research and development by Professor He Guangyi. New type of energy-concentrating hydraulic smooth blasting technology", the company’s "innovative expert" Ma Xiaoli has successfully developed the "small pipe tip reduction machine", the introduction of automatic waterproof board laying trolley, fog cannon health machine, self-propelled hydraulic inverted arch trestle, single Advanced equipment such as arm rock drilling rigs and single-arm wet jetting machines have overcome the complex geological structure of Guanshan, weak and broken surrounding rock, the shallow buried section of the entrance under the provincial highway 304, shortage of engineering materials, special extreme weather of Guanshan, snow disasters, floods Difficulties such as the new crown epidemic have laid a solid foundation for the opening of the Pingtian Expressway to traffic.

The Pingtian Expressway No. 1 project undertaken by China Railway 21st Bureau No. 3 has a total length of 15.985 kilometers. In addition to the Guanshan Tunnel, it also includes the Ma Xia Tunnel, Shengou Bridge, Xian Ma Temple Bridge and roadbed projects. During the construction process, they always adhered to the concept of "forever striving to be the first to lead the whole line, and to play a demonstrative and leading role." The unit’s "AA" credit rating has been successively awarded as the "Youth Work Safety Demonstration Post" by the Gansu Provincial Committee of the Communist Youth League and the Gansu Provincial Safety Supervision and Administration Bureau. The honorary titles such as "Safety Site" and "Quality Engineering Create Advanced Group" have set an example for the whole line.

The Pingliang-Tianshui Expressway is an important part of the G8513 Pingliang-Mianyang National Expressway, and it is also one of the convenient passages connecting Longdong and Longnan in Gansu Province. The completion of the project is of great importance to the implementation of the development of the western region, the development of poverty alleviation in the concentrated contiguous areas of Liupanshan, the development of the Guanzhong-Tianshui Economic Zone, and the strategic deployment of the construction of the China Civilization Inheritance Innovation Zone, the improvement of the national expressway network, and the promotion of the economic and social development of the province. Significance. Editor/Sang Xiaomei