Risk Analysis of Construction Diversion During Initial Stage for Lianghekou Hydropower Project in Yalong River
Lianghekou hydropower project is located on the Yalong River in Sichuan Province, this gravelly soil core-wall rock-fill dam is 295m high, and also the Headwater Reservoir for the cascade hydropower stations of middle and lower reaches of the Yalong River.After the diversion scheme alternative research, water retaining structure adopts the earth-rock cofferdam throughout the year, combined with the rock-fill dam body layout.Blocking river dam is the key item to control the power generation time limit for a project, capacity of the power station is big, diversion structures accident will delay the generation time of the first units, but also will extend the total duration of the project, the economic losses is huge.The safe operation of initial diversion cofferdam provides an important guarantee in order to ensure the normal construction of the dam, so systematic research for diversion risk of retaining earth-rock cofferdam is significant.Diversion system of earth-rock cofferdam is full of many uncertainty factors, considering the uncertainty of water level and capacity, construction flood, discharge capacity of the diversion tunnel, the construction diversion risk calculation model was established, by introducing the varied ratio amplification method to simulate the construction flood process, Monte-Carlo method was used to estimate the diversion risk rate.The calculation model was used in initial diversion risk analysis for Lianghekou hydropower station, first of all, the method was respectively used to calculate the risk rate of cofferdam water level designed by hydraulic method and reservoir flood regulating principle, the results showed that the cofferdam water level designed by hydraulic method is higher, with certain safety margin and optimization space, but the cofferdam water level designed by flood regulating principle is not high enough, and the cofferdam water level corresponding to equivalent risk period is given; afterwards, by comparing to the results of the risk calculation based on flood peak amplifiering method, the risk rate calculated based on the varied ratio amplification method is slightly smaller; and then, through the main random parameter sensitivity analysis, the influence degree of various risk factors on the diversion risk was obtained, providing an important reference for the early construction diversion design and safety evaluation of the Lianghekou hydropower station.
Lianghekou hydropower project construction diversion risk varied ratio amplification method Monte-Carlo method sensitivity analysis equivalent risk period
Zhang Chao Lei Yunhua
Hydrochina Chengdu Engineering Corporation, Chengdu,610072, China
国际会议
昆明
英文
207-213
2013-11-01（万方平台首次上网日期，不代表论文的发表时间）