Tingzikou dam of Tingzikou project

The drainage area above the dam site is 6 1089 square kilometers, accounting for 38.2% of the Jialing River drainage area. The average annual precipitation in the dam site area is 995.8 mm, the average annual flow is 598 cubic meters per second, and the average annual runoff is 65.438+0.89 billion cubic meters. The annual average suspended sediment discharge is 48.8 million tons, and the annual average sediment concentration is 2.54kg/ m3. The normal water level of the reservoir is 458m, the dead water level is 438m, the design flood level is 46 1.3m, the check flood level is 463.07m, and the total storage capacity is 4.067 billion cubic meters. The reservoir reserves a flood control capacity of 65.438+0.6 billion cubic meters (65.438+0.4 billion cubic meters in extraordinary time), which can irrigate 292 1.4 million mu of farmland, and the installed capacity of the power station is 654.38+0/kloc-0.00 MW, and navigation structure is 2×500t. The engineering grade is Grade I, and the engineering scale is relatively large (1). The exposed strata in the dam site area are sandstone, siltstone and claystone of Lower Cretaceous Cangxi Group (K 1C), with a total thickness of about 427~500m, which are layered strata with different hardness. The main sandstone horizons are K 1C6- 1, K 1C4-2, K 1C3-2, K 1C2-3, K 1C2- 1. The Quaternary in the dam area is widely distributed, mainly composed of river alluvial and landslide accumulation. The riverbed alluvial gravel layer is 6 ~13.50m thick; The thickness of the left bank landslide is generally 20 ~ 40m, and the maximum thickness is 63m. In thick sandstone (K 1C2- 1, K 1C2-3, K 1C3-2), * * is distributed in soft rock 3 1, and the soft rock controlled by riverbed is NS2-1-. There are 3 1 weak interlayer in soft rock.