Safety monitoring for hydropower projects provides data pertinent to project safety and enables us to monitor project safety. Additionally, it is an effective approach to bring the project benefits into fully play, upgrade design level, improve construction method, and so on. Therefore, it has drawn wide attention in dam engineering in China and other countries and has developed to a major component in hydropower development.
Surveying Engineering Company of HydroChina ZhongNan Engineering Corporation has set up monitoring PMOs for Longtan, Xiangjiaba, Jiangpinghe, and Suijiang hydropower projects successively. We have made active exploration in such aspects as monitoring instrument, construction technology, computation method, monitoring result analysis and safety monitoring theory, introduced new technologies, studied new experience and theories, and formulated new system in practice, and thus formed a complete set of precise and efficient deformation monitoring solutions that can meet the demands of various operating conditions and projects.
As for data acquisition, full digital acquisition with advanced measuring instruments is adopted, completed with supporting or leading data processing and adjustment software for post-calculation and a system of two-level inspection and one-level acceptance check. That can ensure the offering of high-precision data to the parties concerned in a timely and accurate manner.With regard to measuring instrument, we are equipped with high-precision Leica surveying robot, digital level, and all-weather GPS receiver. In addition, we also use reinforcement meter, anchor bolt stress detector, clinometer, level meter and other internal observation instruments and can provide a full set of technical solutions for internal observation. These instruments have been put into practice and achieved high production efficiency and good economic benefits.
In aspect of project management, we have formulated detailed rules and regulations according to the actual conditions based on the relevant documents issued by HydroChina Corporation and HydroChina ZhongNan Engineering Corporation so as to specify the duties of our staff in an explicit manner, improve staff’s quality and ensure that each PMO have a team with professional competence.
For research findings, the application of GPS geodetic height survey technology in conventional repeated point survey has greatly advanced the timeliness of repeated survey for monitoring network; optimization of GPS observation for areas close to waters has mitigated multipath effect and provided practical solution for subsequent projects; scientific and rational layout of internal observation instruments and external observation points has significantly raised the acquisition accuracy of monitored section through synchronized comparative analysis and expanded the coverage of observation instrument.
(1) Design and implementation of safety monitoring for high slopes
We have completed the monitoring during construction for the slope at left-bank intake (maximum slope height 420m) and Xinkaitan sliding mass in the reservoir area of Longtan HPP in Guangxi, slope at left-bank ship lock (maximum slope height 165m) of Wuqiangxi HPP, intake slope of Dongfeng HPP, and Dahuangya and Laohuzui unstable rock masses for Wujiangdu HPP.
At present, we are conducting the monitoring during construction for Mabukan high slope and right-bank intake slope of Xiangjiaba HPP, and sliding mass downstream of the dam site and Lishanpo quarry for Jiangpinghe HPP.
(2) Deformation observation for projects
We have completed dam deformation observation system design and instrument installation for such hydropower stations as Dongjiang (156m-high double-curvature arch dam), Daguangba (longest dam body in Asia, extending 5842m), Wuqiangxi, Fengtan, Lingjintan, Hongjiang, Jinggangchong, Hongjiadu, Jiangpinghe, and Longtan. Currently we are carrying out, for Jiangpinghe HPP, sliding mass monitoring downstream of the dam site, dam deformation observation, and Lishanpo quarry monitoring, for Longtan HPP, dam deformation monitoring, for Xiangjiaba HPP, Mabukan, Mayanpo, and right-bank intake slope monitoring, observation of slopes upstream of the non-overflow dam sections on both banks, safety monitoring, building settlement observation and Xinji Town transitional shelter settlement observation for new Suijiang County town, for Ludila HPP, deformation monitoring for cableway bridges No. 1 and 2, and for Jinping HPP, emergency monitoring and subsequent monitoring for sliding mass K48 of special access road.目