Research On The Flow-Induced Vibration Response Characteristics Of Slabs In Plunge Pool Of Jinping-1High Arch Dam

The main features in the aspect of flood discharge of those large water resourcesand hydropower projects located in narrow valleys in China are high head,large flowrate and strong discharge power,and then the problem from the safety of the flooddischarge is quite prominent.The safety of protecting structure in high dam plungepool is the key to success or failure of energy dissipation,there is no lack of thedestructive example at home and abroad.Jinping-1belongs to the typical flooddischarge of high arch dams and energy dissipation of flow jets,with thecharacteristics of high head,large discharge,complex hydraulic condition of flooddischarge energy dissipation,complex working condition and destruction mechanismof plunge pool.Therefore,the safety problem of energy dissipation in plunge pool isone of main factors to Jinping-1operation safety.This paper combined with prototypeobservation data of the vibration of slabs in plunge pool of high arch dam,mainlyJinping-1.We researched vibration characteristic of plunge pool using some signalprocessing technologies. The main achievements of this paper include as follows:（1）Study on the hydrodynamic pressure characteristics of slabs in plunge pool ofJinping-1.Combined with the prototype observation data and model test results,theamplitude,distribution and frequency domain characteristics of fluctuating pressure ofslabs in plunge pool was analyzed.（2）Study on the flow-induced vibration characteristics of slabs in plunge pool ofJinping-1.Combined with the prototype observation data of Jinping-1,it mainlyanalyzed the characteristics of vibration response intensity and vibration process andthe influence of opening mode and discharge on the vibration intensity under differentoperation conditions.Using the method of modern spectrum estimate,it would executespectrum analysis for vibration signal.The distribution of dominant frequency wasstudied.According to statistics principles,the mathematical and statistic eigenvalue ofvibration signal of slabs in plunge pool of Jinping-1was analyzed.（3）Study on the flow-induced vibration characteristics of slabs in plunge pool ofhigh arch dam.The vibration of slabs of the Ertan,Laxiwa,Jinping-1and Xiluoduplunge pool are analyzed according to prototype observation data by applying themodern spectral analysis method and correlation analysis method.The properties inthe frequency extent and the correlation of concrete slabs in plunge pool of high arch dam are discussed.（4）The numerical simulation calculation of vibration response of slabs in plungepool of Jinping-1and safety monitoring index.Based on the finite element theory andcalculation method,the finite element model of slabs of Jinping-1was built in theANSYS.The measured water pressure load was loaded into the finite elementmodel.Using the calculation results that the water pressure load was measured byprototype contrasted prototype vibration displacements,the reliability of calculationmodel was verified.Then the dynamic response on vibration displacements of slabsunder limit flood discharge conditions were numerically calculated,and the calculatedresults were analyzed.Finally,we integrated prototype observation results,combinedwith the model test,numerical simulation and calculation results,used for referencefrom other engineering experience,the various range of monitoring index of slabs inplunge pool of Jinping-1was put forword under different safety warning levels.