General situation of Xiaolangdi water control project

Xiaolangdi Water Control Project is located on the main stream of the Yellow River, at the downstream of Sanmenxia Water Control Project130km, and 40km north of Luoyang City, Henan Province, with a control basin area of 694,000 square kilometers, accounting for 92.3% of the Yellow River basin area. The south bank of the dam site is Xiaolangdi Village in Mengjin County, and the north bank is Liaowu Village in Jiyuan City, which is the outlet of the last canyon in the middle reaches of the Yellow River.

The crest elevation of Xiaolangdi Water Control Project is 28 1m, the normal high water level is 275m, the storage capacity12.65 billion m3, the sediment retention capacity is 7.55 billion m3, the water and sediment regulation capacity/kloc-0.05 billion m3, and the long-term effective storage capacity is 5/kloc-0.00 billion m3, which is designed as a once-in-a-millennium flood. The limited water level for ice prevention is 266m m m, the maximum flood control flow is10.7 trillion m3/s, and the normal dead water level flow is slightly more than 8,000 m3/s. Under the normal water level of Xiaolangdi Reservoir, the affected area is 277.8km2. The construction area of 23.33km2 * * involves 33 townships in 8 counties (cities) in Henan and Shaanxi provinces, including Jiyuan, Jin Meng, Xin 'an, Mianchi, Shan County, Pinglu, Xiaxian and Yuanqu, with an annual relocation of 200,000 people. In September, 199 1, the preliminary project of Xiaolangdi water control project started. In April 2009, all the projects passed the completion acceptance, which was a key construction project during the Eighth Five-Year Plan.

After the completion of the project, the reservoir area is 272.3 square kilometers, and the control basin area is 694,200 square kilometers. The total installed capacity is 6.5438+0.8 million kilowatts, and the average annual power generation is 56.5438+0 billion kilowatt hours. The annual water supply can be increased by 4 billion cubic meters. The banks of Xiaolangdi Reservoir are Lushan Mountain, Shaoshan Mountain and Mangshan Mountain in Qinling Mountain System. Wutang Mountain in Zhongtiao Mountain System and Taihang Mountain System. Its completion will effectively control the flood of the Yellow River, raise the flood control standard of Huayuankou in the lower reaches of the Yellow River from once in 60 years to once in a thousand years, basically lift the threat of ice flood in the lower reaches of the Yellow River and slow down the siltation in the lower reaches. Xiaolangdi Reservoir can also use its long-term effective storage capacity to regulate non-flood runoff and increase urban and industrial water supply, irrigation and power generation. It is in the key position to control the downstream water and sediment, and controls the sediment transport of the Yellow River at 100%, which can retain 7.8 billion tons of sediment, which is equivalent to that the downstream riverbed will not be silted or raised for 20 years.

The main project started on September 1994, and was cut off on October 28th 1997/kloc-0. The first power generation unit was completed on February 30th, 2006, with a total construction period of 18. The total storage capacity of the reservoir is 654.38+02.65 billion cubic meters, and the long-term effective storage capacity is 565.438+00 billion cubic meters. The project focuses on flood control and siltation reduction, giving consideration to water supply, irrigation and power generation, storing clear water and discharging mud, killing insects and promoting benefits, and comprehensive utilization.

Xiaolangdi project consists of river dam, flood discharge structure and water diversion and power generation system.

Xiaolangdi dam is a rockfill dam with inclined core wall. The designed maximum dam height 154m, dam top length 1667m, dam top width 15m and maximum dam bottom width of 864m. The dam body is filled with 58,500 cubic meters, and the foundation concrete cutoff wall is 1.2 meters thick and 80 meters deep. Its filling quantity and concrete cutoff wall are the highest in China. The dam crest elevation is 28 1 m, the normal water level of the reservoir is 275 m, the water storage area is 272 square kilometers, and the total storage capacity is12.65 billion cubic meters. The reservoir is east-west banded with a length of about 130 km. Narrow at the top and wide at the bottom, with an average width of 2 km. It belongs to the canyon river reservoir. The average annual flow of the dam site is 1.327 m3/s, and the sediment discharge is1.600 million tons. After the dam is completed, it can control 92.3% of the whole basin area.

Due to the limitation of topographic and geological conditions, and the operation requirements of preventing the siltation and blockage of the intake, the flood discharge, sediment discharge and diversion power generation buildings are all arranged on the left bank, forming the characteristics of centralized arrangement of the intake, cavern group and outlet stilling basin. There are more than 100 caves in the thin mountain with an area of about 1km2. Nine spillway tunnels, six diversion tunnels and 1 irrigation tunnels are combined to form 10 intake tower, which is arranged in a straight line, with the upstream surface in the same vertical plane, the total width of the front is 276.4m, and the maximum height is113m. The water inlets of each tunnel are staggered, forming the overall layout of high-level flood discharge and sewage discharge, low-level flood discharge and sediment discharge, and middle-level water diversion and power generation, which can prevent siltation at the water inlets, reduce the velocity in the tunnel, reduce the abrasion of the runner and improve the reliability of gate operation. Among them, six diversion power generation tunnels and three desilting tunnels * * * form three power generation intake towers, each of which is provided with two power generation tunnel inlets and a drainage tunnel inlet in the middle of its lower part, with a height difference of 15-20m, so that coarse sand can be discharged through the desilting tunnels, and the abrasion to the hydraulic turbine can be reduced. The nine flood discharge and sediment discharge tunnels are composed of three orifices, three open-flow tunnels and three sediment discharge tunnels converted from three diversion tunnels, which are arranged in parallel with 1 spillway on the plane. A secondary stilling basin with a total width of 356 meters, a total length of 265,438+00 meters and a maximum depth of 28 meters is set at the outlet to concentrate and disperse the above 65,438+00 streams and flow downstream through the spillway. The entrance and exit high slopes formed by the excavation of intake tower and stilling basin are as high as120m. In order to ensure the stability of high slope, comprehensive treatment measures such as load reduction, drainage, 1 100 prestressed anchor cable support and vertical anti-slide pile reinforcement have been taken, and good results have been achieved.

The diversion and power generation system is also arranged on the left bank of the hub. Including 6 power generation diversion tunnels, underground powerhouse, main transformer room, gate room and 3 tailrace tunnels. Six 300,000-kilowatt mixed-flow hydro-generator sets are installed in the power station, with a total installed capacity of 6.5438+0.8 million kilowatts, and the average annual power generation for many years is 4.599 billion kilowatt hours /585. 1 100 million kilowatt hours (before/after 10).

The main project construction of Xiaolangdi Water Control Project adopts international bidding, with the Yellow River contractor as the responsible party, the German company Xuplin, a joint venture between China, Germany, Italy and France, and Dumex, a joint venture between Xiaolangdi and France, as the responsible party for the power generation system. 1994 July 16 The contract signing ceremony was held in Beijing.

The development target is mainly flood control (anti-icing) and siltation reduction, taking into account water supply, irrigation and power generation, storing clean water and discharging sludge, eliminating pests and promoting benefits, and comprehensive utilization. Xiaolangdi Water Control Project has an important strategic position, huge scale, complex geological conditions, special water and sediment conditions and strict application requirements, and is called one of the most complicated water conservancy projects in the world by Chinese and foreign water conservancy experts.