The T3 terminal of Lhasa Gonggar International Airport, which was completed not long ago, has an altitude of 3,569 meters. It is one of the highest airports in the world and the largest plateau airport in the world. During the construction of the project, the unique concrete technical construction problems were solved. According to the supply of local materials, the project implemented the C50 self-compacting concrete configuration for the first time in Tibet, which solved the mixing of fly ash, mineral powder, silica fume and other concrete The problem of lack of materials. C50 self-compacting concrete was poured into the 12 steel columns holding up the airport lotus roof. In the process, the project changed the traditional concrete pouring technology and adopted special pumping jacking technology to avoid the quality defects such as loose concrete in the steel pipe column in the plateau environment and the lack of dense holes.
After nearly 14 years of arduous struggle, the Yunnan Dali Rui (Li) Xiuling Tunnel, which set a number of domestic and foreign records, was completed not long ago. The Xiuling Tunnel is located in Yangbi County, Dali Prefecture, Yunnan Province, with a total length of 17.6 kilometers and a maximum burial depth of 1115 meters. The characteristics of deformation, water gushing and mud outburst, high ground stress, high seismic intensity, and high ground temperature are rare in China, and it is a Class I high-risk tunnel. The tunnel has successively carried out more than 100 subject researches, including 2 national patents, 3 provincial and ministerial scientific research achievements, and 41 enterprise scientific research achievements, which have accumulated valuable experience for the construction of special long and difficult tunnels in my country.
The Xiangli Expressway, which opened to traffic on December 31, 2020, is an important support project for the state to support the economic and social development of Tibetan areas. It is also the first expressway in the Tibetan area of Yunnan Province and the highest expressway in Yunnan Province. The total length of the project is 140.31 kilometers, with 141 bridges and 73114 meters of tunnels. The project overcomes the difficulties of Shangri-La’s high cold and lack of oxygen, severe cold weather, and short effective construction period. It overcomes the key problems of the durability of structural concrete under the action of multiple destructive factors on the expressway, and designed high performance C30 to C55 suitable for expressway bridges. The series of concrete products promote the use of high-performance concrete with impermeability grade not lower than P12, crack resistance grade not lower than L-III, frost resistance grade above F100, 56d electric flux less than 1000C, and highest frost resistance grade above F400. A large number of applications in the project, accumulatively promoted the application of more than 3 million cubic meters of high-performance concrete, which has improved the structural life of expressway projects in harsh environments.
The achievements of our country's infrastructure construction are far more than these. Various "world's best" constantly refresh people's cognition... |