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How to save 3,000 acres of land

China.org.cnUpdated: April 9, 2018

Interpretation of new technologies for large-scale canal design and construction

According to recent data from the Ministry of Land and Resources of China, during the 11th Five-Year Plan, we made strenuous efforts to ensure that China's farmland remains at or above a minimum of 120 million hectares. As a result, we succeeded in maintaining 104 million hectares of basic farmland, but we still have a long way to go. In the 11th Five-year Plan, one major category for its section on national science and technology support is the "new technology research for large canal design and construction." Undertaken by the South-to-North Water Diversion Project Construction Management Bureau of Shandong Province, the research efforts have helped to save nearly 200 hectares of precious land resources in the construction of the Jiping main canal project. This achievement has filled many gaps in the design and construction technique of long-distance, large-scale water transmission canal. Inventions and utility models developed during the project were granted more than 20 patents, reaching the advanced world standards.

Optimization system leads to efficient design

Water and land resources are the foundations for social and economic development. The effective protection of these resources is key to accelerating the transformation of economic development mode.

Luo Hui is the person in charge of the technology research for large canal design and construction, as well as the deputy director of the South-to-North Water Diversion Project Construction Management Bureau of Shandong Province. He said that, based on the long-distance canal line optimization and earthwork balance system, and through scientific allocation of land and water resources and elevated utilization efficiency of these resources, the project has succeeded in combining of ecological, economic and social benefits.

On a computer screen, a software program launches and a few mouse clicks bring up farmlands, villages and canals. The digital recreations of the buildings and landscapes are projections of their real-life counterparts. This software is not a popular online game, but a long-distance canal optimization and earth balance system using virtual reality.

An operator enters data into the design system and clicks on the canal optimization design button. In just a few minutes, several design options are generated for the operator to choose between and compare. Jin Hongchang, one of the leading developers of the software, said it helps shorten the design time from one to two months to one to two days, dramatically improving efficiency.

The design and construction of large-scale canals are the highlight of the South-to-North Water Diversion Project, and the optimization system has helped to save a large amount of valuable land resources. Designers can optimize the allocation of all earthwork in the three-dimensional visual environment, and the deployment of earth and stone in the early design stage. This way, they can figure out the design scheme by using the smallest amount of land and building resources. By using the optimized plan, the Jiping Canal Project achieved a balance of earthwork, in large parts avoiding the disposing and borrowing of soil, and excess use of land. The Jiping Canal Project was completed by the end of 2007, with the actual land use reduced by 198 hectares compared with the preliminary design, saving 50.13 million yuan.

A flexible armor for the canal

The geology and terrain conditions along the route of the project are complex, and the hydrological and meteorological conditions are sophisticated. Therefore, it is not easy to ensure that water is led to the north without leakage. To do this, it is essential to put a thin layer of concrete coating on the embankments, which is called canal lining.

However, the water inside and outside is not gentle, the internal water flow is large, and the water pressure is fierce. Meanwhile, due to the high groundwater level, the external water cannot be underestimated in its pressure either. It is no exaggeration to say that if there is a small crack, the canal will be instantly ripped, causing disastrous consequences. In brief, the canal must be solid, with moderate thickness, just like the soft armor of a porcupine.

The Jiping main canal, the first project to begin construction in the South-to-North Water Diversion Project, was the first to face this problem. The existing water diversion projects in China, such as the project of water diversion from the Yellow River into Qingdao, adopted manual operation in canal lining, which had taken a lot of time and labor, with construction quality compromised. The South-to-North Water Diversion Canal is thousands of kilometers in total length. Hence, to ensure construction quality and efficiency, mechanical automation must be applied to canal lining.

Luo said that the South-to-North Water Diversion Project Construction Management Bureau carried out independent development based on the designs of imported mechanical automated canal lining machines. With consideration to specific requirements of the construction, they made some adjustments to the borrowed technology, and finally succeeded in completing the concrete lining facilities after four years of painstaking research and development, with the help of such R&D institutes as the Shandong Water Diversion Engineering Research Center and the Shandong Survey and Design Institute of Water Conservancy.

Compared with the vibro-rolling sliding machines used by other countries, the self-developed large-scale concrete lining equipment features versatility, strong adaptability, and easy operation, and the cost is only one third to one fifth of that of similar foreign facilities. Operating efficiency is cheaper and 10 to 16 times more efficient than artificial lining. Sampling tests showed that the passing rate of the unit project is 100 percent, and the excellent product rate is over 90 percent. The facility is now widely used in the central route of the South-to-North Water Diversion Project.

Favorable social and economic benefits

More than 20 technological innovations developed during the "new technologies for large-scale canal design and construction" contributed to the construction of the water diversion project. These innovations played an important role in accelerating the project's construction, ensuring project quality, saving land resources, and promoting industrial upgrading, and has brought us significant social and economic benefits.

The results from the "Research on the Jiping Canal Design and Optimal Allocation of Earth and Stone Work" were approved by experts in December 2006. The report says that the research achieved the optimization of large-scale canal engineering design and deployment of earth and stone, filling the gap in the research field, achieving significant economic and social benefits, having significant promotional and application value, and that the overall results have reached the advanced world standards. At present, the research results have been applied to other parts of the South-to-North Water Diversion Project in Shandong province. The canal optimization design work was carried out as early as the feasibility study stage, which not only improved the design work's efficiency, but also saved land resources and project investment to the maximum extent.

In August 2006, the canal lining molding equipment passed the product identification by the experts from the Ministry of Water Resources. This achievement helped to fill in a technological void in China, and achieved the serialization, industrialization, and construction technology standardization of large-scale canal concrete mechanization molding equipment. Moreover, it has won four national invention patents and 10 utility model patents. The project won the second prize of the National Science and Technology Progress Award.

The "New Technologies for Large-scale Canal Design and Construction" is one of the 15 subjects of the major project of "Research and Application of Several Key Technologies pertaining to the South-to-North Water Diversion Project" in the 11th Five-Year Plan's National Science and Technology Support Plan. The South-to-North Water Diversion Bureau of Shandong Province is the first unit to undertake the project's construction. It was jointly completed by the Shandong Survey and Design Institute of Water Conservancy, Hohai University, Nanjing Hydraulic Research Institute, Route Eastern Shandong Province, and the Shandong Water Diversion Engineering Technology Research Center. In November 2010, the project passed inspections and was accepted by the South-North Water Diversion Office of the State Council.