From May 27 to May 29, 2021, the Administrative Center for China’s Agenda 21 organized a comprehensive performance evaluation meeting in Nanjing for the project of Capacity Improvement and Safety Guarantee Technologies of Long-Distance Water Supply Works in Alpine Regions, led by Nanjing Hydraulic Research Institute, under the National Key R&D Program of China in the 13th Five-year Plan Period. Relevant leaders of MWR Department of International Cooperation, Science and Technology attended the meeting. The meeting saw the attendance of more than 40 people composed of subject leaders and technical backbones of the project participating institutions, including CAS Northwest Institute of Eco-Environment and Resources, Xinjiang Ertsis River Basin Development and Construction Administration, Northwest A&F University, Xinjiang Institute of Water Resources and Hydropower Research, and China Institute of Water Resources and Hydropower Research.
The expert panel watched the introduction and demonstration applications of the project key technologies, and listened to the relevant reports on the execution of the project by Prof. CAI Zhengyin in charge of the project. After reports review, inquiry and discussion, it was unanimously agreed that the project had strong theoretical innovation, outstanding application technology originality and good integration demonstration effects. The project has effectively promoted the scientific and technological progress in the field of efficient operation and safety guarantee of long-distance water supply works, with broad application prospects, achieving the expected objectives of the project and providing strong support for the goal realization of a special project Efficient Development and Utilization of Water Resources. The expert panel approved the comprehensive performance evaluation of the project.
Facing the needs of engineering capacity improvement and safety guarantee of long-distance water supply channels in alpine regions with harsh environment, a systematic research has been carried out on channel deterioration mechanism, the optimization design method of new section structure in alpine regions, channel frost resistance upgrading and transformation technologies, low-temperature water supply operation control technology, channel monitoring, early warning and health diagnosis technologies, and emergency dispatching and rescue technology. A safety evaluation and guarantee system of long-distance water supply channels in alpine regions has been constructed. The main innovations include the following:
1. A double reciprocal feed failure mechanism of strength attenuation and structural damage under the "wet-dry+freeze-thaw" cycle of channels in alpine regions has been revealed for the first time, the channel water-heat-force multi-field coupling numerical analysis and hypergravity simulation test platform developed, and the theory and method of channel frost resistance design put forward, laying a theoretical foundation for ensuring the efficient and safe operation of channels in alpine regions.
2. A complete set of technologies, equipment and construction methods for frost resistance upgrading and reconstruction of channels in alpine regions has been developed, a 3D anti-drainage and anti-sliding system of channel leakage established, and hot melt adhesive bonding plus welding technology for new and old anti-seepage membranes in channel upgrading and reconstruction invented, improving the water supply efficiency of channels in alpine regions in China.
3. A digital channel simulation system of hydraulic control in ice age has been established, and a channel local ice melting technology integrating floating solar blankets for channel water temperature increasing and thermal insulation, auxiliary heating of channel foundation gravel pile and the surface heating of lining plate and an efficient channel composite thermal insulation cover plate developed, providing a new solution for channel low-temperature operation control in alpine regions.
4. An on-board channel intelligent and nondestructive health detection system has been integrated and innovated, and an all-weather unattended safety monitoring system, an early warning and prediction cloud platform and a channel emergency inspection system and dispatching platform developed based on BIM technology and UAV automatic identification, effectively ensuring the operation safety of long-distance water supply channels in alpine regions.
The project achievements have been applied in large-scale water supply works in Northern Xinjiang. The water supply period of upgraded channels has been extended by more than 15-30 days every year, and the frost resistance of linings and water supply capacity increased by 60% and 25%, respectively, effectively ensuring the operation safety of long-distance water supply channels in alpine regions, with remarkable economic, social and eco-environmental benefits. The results may be applied to other major projects of water resources and transportation in cold areas, with good application prospects.
