Foziling reservoir

Foziling reservoir

Foziling reservoir, the eighth batch of national key cultural relics protection units

. It is located in the upper reaches of the East source of Pi River, a tributary of Huaihe River. The dam site is 17 kilometers southwest of Huoshan County, Anhui Province. The runoff of Manshui River and Huangwei River enters the reservoir.

Foziling hydropower station is the first hydropower station in Huaihe River Basin. Based on flood control, combined with irrigation, power generation and shipping, it is the design of Foziling reservoir project headquarters of Huaihe River Regulation Committee. The project started in January 1952 and was completed in November 1954. It took two years and 10 months. The actual control area is 1270 square kilometers. The reservoir has a total storage capacity of 496 million cubic meters, corresponding flood level of 130 meters, profitable storage capacity of 120 million cubic meters and dead storage capacity of 125 million cubic meters in flood season. The flood control standard is once in a thousand years.

As an important part of the Huaihe River Regulation Project, Foziling reservoir not only greatly improves the flood control standard of the middle and lower reaches of the Pi River, but also plays an auxiliary role in flood storage of the main stream of the Huaihe River. With the completion of the large and medium-sized reservoir project in the upper reaches of the Pi River, the irrigation industry in the Pi River Basin has also developed rapidly. A number of irrigation projects have been completed, such as the Xiaopi River irrigation area, the Pi River irrigation area and the PI yuan canal irrigation area.

Main works

dam

Foziling dam consists of 20 buttresses, 21 arches and gravity dams at both ends. The axis of the dam crest is 510 meters long, and the dam buttress is an open web, which is composed of two buttress walls connected with the upper and lower panels by transverse partition walls. The width of both sides of the dam stack is 6.5m, the slope of the upstream surface is 1 ∶ 0.9, and the slope of the downstream surface is 1 ∶ 0.36; the semi-circular arch with an inner diameter of 13.5m is supported on the upstream surface of the dam stack. The gravity dam on the east bank is 30.1 meters long, and the gravity dam on the West Bank is 66.4 meters long. In the upper part of the dam at the elevation of 117.56 meters, the length of the slab dam is 45 meters. Eight flood discharge steel pipes with a diameter of 1.975m are buried in the dam stack. A 1.75m square gate and a diffusion flip section are set at the outlet section. There are two steel pipes for power generation, the air injection valve with diameter of 1.25m is installed at the tail of the steel pipe, and the fork pipes in the middle of the steel pipe are respectively introduced into the workshop in the arch. There is one irrigation drainage steel pipe, and its tail is also controlled by 1.25m air injection valve.

Foziling dam is the first reinforced concrete multi arch dam designed and constructed by ourselves after the founding of the people's Republic of China. The whole design process is carried out under the condition of exploration and construction at the same time, and there is neither experience nor specification to follow. Wang Huzhen and other water conservancy experts led a group of young and middle-aged technical cadres to learn and do at the same time. In the design, the major technical problems such as stress analysis during transverse earthquake, dam pier stability and dam foundation grouting were overcome.

After the dam was completed in September 1954, it has withstood the tests of high water level, earthquake and low temperature. Cracks occurred in the dam body, and cavitation and vibration occurred in the steel pipes in the dam stack. In 1965, when the reservoir was emptied, the cracks in the arch tube, pile head and pile body were found out and the causes were found out. Some treatment measures were taken, such as cutting slots to fill the cracks, coating anti-seepage materials, strengthening the arch, grouting and reinforcing the dam foundation. In 1969, there was a flood and the reservoir overtopped the dam. After the flood, a comprehensive inspection was carried out. Only the slopes on both sides of the dam and the bedrock behind the dam were seriously scoured, and no abnormality was found in other parts of the dam, indicating that the design of the dam was successful. Before the flood season in 1970, the hillside was protected with concrete, and the scouring pit at the dam toe was backfilled with concrete. After the rainstorm in Henan Province in 1975, according to the requirements of the Ministry of water and electricity, the reinforcement and heightening of Foziling reservoir should first reach the check of once-in-a-thousand-year return period; while improving the flood control capacity, the problems existing in the operation of the dam should be solved, the stability and safety of the dam should be improved, and the dam stress should be improved; the irrigation and power generation should be affected as little as possible. After comparison, it is selected to heighten the dam by 1.5m, Backfill Concrete in no.13-20 pile, and carry out epoxy grouting for dam cracks under different conditions. When heightening, roughening, grooving and anchor reinforcement shall be taken on the old concrete surface of the original dam crest to integrate the new and old concrete. The foundation of the right bank of the dam is strengthened by curtain grouting; drainage holes and observation holes are added on both banks; cement consolidation grouting is carried out on the fault fracture zone and interlayer dislocation surface under several pile foundations of the riverbed. It is safe to check the earthquake resistance of the dam according to 8 degrees.

The straight line length of the dam after reinforcement and heightening is 513m. Among them, the multi arch dam is 413.5m long, the East gravity dam is 31.6m long, and the West gravity dam is 67.9m long. The highest dam height is 75.9 meters.

spillway

The spillway is located in the east bank Valley, with open overflow and open channel side channel. From 1951 to 1954, the design was changed several times; in the planning of Huaihe River Basin and Pihe reservoir group, it was decided to build Mozitan reservoir in the upstream and expand the spillway of Foziling reservoir. According to the design of spillway expansion compiled in 1956, the spillway is selected as 5 holes, with a net width of 10.6m for each hole. The double leaf flat steel gate has a bottom height of 112.56m and a top elevation of 125.96m. The spillway gate is connected with open channel and side channel narrow valley to discharge into Pi River downstream of the dam. In August 1975, after the flood in Henan Province, the dam was strengthened and the spillway was expanded in the West. The structure, size and gate type of the expanded one are the same as those of the original spillway. The side pier is placed close to the rock surface after excavation. The entrance section of the upstream West Bank is connected with the slope protection of the gravity dam head by concrete; the side wall of the downstream outlet section is poured close to the rock surface, and the upstream face is upright. In order to strengthen the combination, steel bars are set on the rock wall.

power station

Foziling hydropower station is the first hydropower station in Huaihe River Basin. Initially designed for Anhui Provincial Department of industry, with an installed capacity of 4000 kW (1 set of 2000 kW and 2 sets of 1000 kW). After the flood in 1954, it was designed by Shanghai Hydropower Design Institute and expanded three 3000 kW units with a total capacity of 11000 kW, including two 1000 kW units and three 3000 kW units. The workshop is in arch 19 and 18. In 1958, another expansion was carried out, adding two 10000 kilowatts each, which was designed by the Design Institute of Anhui Provincial Department of water resources and electric power, and a new plant was built behind the dam of no.7-no.10 pile. The steel pipes in stacks 7-10 are used for flood discharge, and the steel pipes in stacks 12 and 19 are removed to lengthen the steel pipes in stacks 7-10. After expansion, the total installed capacity is 31000 kW, and the planned annual power generation is 124 million kwh.

Design and construction

From March to June 1950, the General Administration of Huaihe water conservancy engineering organized the investigation of the Pi River and proposed that two reservoirs, Foziling and Changzhuyuan (namely Xianghongdian), could be built in the upper reaches of the East and West sources of the Pi River. After the flood in July 1950, the Huaihe River Control Committee, together with the relevant units, carried out a re survey in November 1950 in accordance with the policy of "storing, discharging and planning". In April 1951, the second Huaihe River harnessing conference decided to build Foziling reservoir in the general plan for Huaihe River harnessing and the key points of the project in 1952. After that, geological survey, dam site and reservoir area survey and Hydrometry will be carried out. At that time, there was a lack of data on the construction of multi arch dam in China. Water conservancy experts represented by Wang Huzhen solved the problems in the design and construction of multi arch dam with a scientific attitude and the spirit of hard study. In only three years, they completed the construction task of the first reinforced concrete multi arch dam in Asia at that time. The construction of the reservoir trained a large number of talents in water conservancy and hydropower construction.

Foziling reservoir project headquarters is set up by Huaihe River Management Committee to be responsible for the construction of Foziling reservoir. On October 10, 1951, the headquarters was established, and personnel were mobilized from all aspects. In July 1952, the first division of engineering water conservancy of PLA participated in the reservoir construction. From Jiangsu, Shanghai and other places to recruit skilled workers. Migrant workers come from Huoshan County and Fuyang county. At the most, 18900 people participated in the construction. At the end of October 1951, the road from Lu'an to Foziling was completed. It took only 27 months from July 1, 1952 to September 16, 1954.

dam

The original river bed diversion is adopted for the reservoir project, which is constructed in two phases, with diversion on the east bank first and enclosure dam on the West Bank. In the second phase, the upper and lower approach rivers are excavated at the foot of the Western River. The river water is discharged through arch 8, 9 and 10, and a dam is built in the East. On January 9, 1952, the foundation of Foziling dam was cleared. On March 1, the first phase of steel sheet pile earth rockfill dam project started and ended at the end of June. During the excavation of foundation clearing, a broken zone was found in the rock stratum on the West Bank, and the dam axis was moved down by 12 meters. The foundation clearing work was delayed until March 1953. The second phase of foundation clearing work was broken due to dam seepage and flood impact. It was not fully carried out until the beginning of October 1953, and was completed by the end of the year. Since the beginning of July 1952, concrete pouring has been carried out in two phases. The whole project adopts self-management mode, with machinery as the main part and manpower as the auxiliary part. During the construction, the cold and low temperature in spring of 1953 once affected the concrete quality and pouring progress. Concrete mixing, transportation and pouring are carried out by means of dispersing, moving and fixing, combining machinery and manpower according to different pouring height and position, so the quality control and requirements are strict. In late July 1952, the reform of construction management and labor mix began. The construction unit has established the "regional production management system" and implemented the "parallel flow process" to improve the efficiency and complete the first phase of concrete pouring one month ahead of the original plan. The second phase of concrete pouring overcame the difficulties of flood, dam damage and construction. On June 6, 1954, all the concrete was poured to the elevation of 127.46 meters and successfully blocked the dam

Chinese PinYin : Fo Zi Ling Shui Ku