The upgrading of the strong earthquake monitoring system of Luding Hydropower Station was successfully completed

Luding Hydropower Station is located in Luding County, Ganzi Prefecture, Sichuan Province. It recommends a 22-level development hydropower level 12 power station for the planning and adjustment of the main stream of the Dadu River. The main task of the project is power generation. The upstream of the power station is about 44km away from Kangding County, and the downstream is 2.5km away from Luding County. National Highway 318 passes through the project area, and the external traffic is relatively convenient.

The Luding Hydropower Station is a second-class project and a large-scale project (Ⅱ), with a normal storage level of EL1378.00m, a total storage capacity of 240 million m3, daily regulation performance, and an installed capacity of 920MW. The dam is a clay-core rockfill dam, with a crest height of EL1385.50m, a maximum height of 79.5m, a crest length of 526.7m, and a crest width of 12.0m. The top height of the core wall is EL1383.00m, the top width is 4.0m, and the bottom height is EL1306.00m. The anti-seepage of the dam foundation adopts a suspended concrete anti-seepage wall with a thickness of 1.0m and a maximum depth of 110m.

 In order to record and analyze the vibration response of hydraulic structures such as dams and powerhouses under the action of earthquakes, the existing strong earthquake monitoring system of the hydropower station was designed and installed by Chengdu Survey, Design and Research Institute around 2013. A total of 4 sets of strong earthquakes were installed. The instruments are distributed in the 0+193 observation room and workshop observation room of EL1384m, EL1346m, and EL1325m behind the dam.

Due to the early construction time of this strong earthquake monitoring system, the vibration picker and the strong earthquake recorder used are unstable in operation, the anti-interference ability is poor, and the failure or damage occurs. In recent years, digital seismograph and its supporting equipment have been widely used in watersheds and other domestic power stations. Therefore, it is necessary to reform the strong earthquake monitoring system of hydropower stations.

    In principle, this transformation will still refer to the previous design plan. First, replace two sets of strong motion instruments, and then replace the others one after another. The two sets of strong motion instruments are composed of a G01NET-3-A type strong motion instrument, a QZ2013 force balance accelerometer and supporting accessories. The installation locations are the EL1384m0+193 observation room on the top of the dam and the dam. The EL1325m0+193 observation room at the bottom. For the time being, the network will not be built to build an automation system, and only record and collect data at each replacement measuring point.