After the completion of the reservoir, the earth dam settlement is large, and serious cracks appear, with a crack depth of 7 meters. From 1954 to 1955, it was processed twice, but it was not completely solved. 1956 to 195. After reconstruction, the dam height is increased to 47.88m, the wave wall at the top of the dam is 1.0m, and the dam length is 13 16m. The spillway is equipped with an 8-hole gate with a width of 12m, a height of 8m and a flow of 4,280m3/s; The maximum flow of the water conveyance tunnel is 208 cubic meters per second.
The total capacity of the reservoir is 295 million cubic meters. Investment15.54 million yuan. In pp 1958, due to the emphasis on the role of small upstream projects, six flood gates were removed and transferred, and the masonry overflow weir was blocked. 1964 after the flood, it was found that the flood discharge capacity was insufficient, and the gate was reinstalled. After 1975 flood, in order to prevent catastrophic flood, the 17 explosion chamber was built on the east auxiliary dam on the left side of spillway gate. In case of a once-in-a-thousand-year flood, the dam will burst and flood. 1978 Winter Solstice1At the end of 979, when the north main canal is newly built in the irrigation area, a water conveyance tunnel will be built at the left dam head. Tunnel length 134.30m, gate with double holes, height 2m, width 1.6m, and maximum flow15m3/s. ..
From 1955 to 1987, the cumulative water inflow is 4.5 billion cubic meters, and the cumulative water supply is 2.5 billion cubic meters. The inflow peak flow is more than 1000m3/s for 7 times, and the maximum discharge after reservoir regulation is169 m3/s. In which1June 265438+June 2 1 day inflow peak flow is 6 180 m3/s, and the reservoir only discharges 155 m3/s, reducing the flood peak by 97.5%. For more than 30 years, it has ensured the safety of about 400,000 mu of farmland downstream, which can be used as water source irrigation area of 230,000 mu, with remarkable benefits.