Inverse Analysis Method Of High Arch Dam Structure Under The Excitation Response Based On Dynamic Fingerprint

In China,the hydropower resource developable capacity and the number of high dams in service and dam height rank first in the world.The high concrete arch dams are one of important types of hydraulic structures in the development of hydropower.Fatigue damage of high arch dam in service period is caused by dynamic load and uncertain environmental factors,which leads to the evolution of material mechanical parameters of dam body and foundation.Discharge excitation is an important factor in the aggravation of the cumulative damage of arch dams.Therefore,it is a significant scientific problem to carry out inverse analysis of dynamic parameters of arch dam with excitation response information of high arch dam.One of the methods to solve this problem is to carry out dynamic fingerprint identification of high arch dam based on the prototype excitation response signal,to establish the simulation analysis model of arch dam structure in accordance with the actual working condition,and to invert the parameters of the dynamic numerical model of arch dam based on the identified dynamic fingerprint information.The main research contents of this paper are as follows:(1)Time-frequency analysis is performed on the measured vibration signals of the arch dam structure.An improved wavelet threshold-EMD de-noising method is proposed based on the analysis of the main types of noise,and applied to the de-noising pretreatment of the measured vibration response data of a high arch dam.Based on the de-noising signal,an improved HHT-RDT method for the dynamic fingerprint identification of arch dam structures is proposed.The ability of identifying the dynamic fingerprint information of High Arch Dam is enhanced.And a method of dynamic fingerprint information excavating for High Arch Dam structures based on flow-induced response signals is proposed.(2)The dynamic numerical modeling method of high arch dam based on the coupling of "reservoir water-dam-foundation" system is systematically discussed.The additional mass method and the fluid-structure coupling method are used to simulate the coupling form of high arch dam and reservoir under the actual working conditions.Based on the two types of dam-reservoir coupling,the dynamic numerical model of the high arch dam under the system of "reservoir-dam-foundation" are established.Comparing the results of the two models with the results of the identification of the prototype test signals,the more suitable dynamic numerical model of High Arch Dam is selected.(3)The dynamic elastic model which has great influence on the structural analysis is selected as the parameter to be inversed based on the established dynamic numerical model of high arch dam under the system of "reservoir-dam-foundation".After training the multi-objective Support vector machine model to establish the proxy model to instead of dam dynamic model,the chicken swarm optimization algorithm is used to complete the optimization inversion of the high arch dam material dynamic parameters.The precision and efficiency of parameter inversion are improved effectively.And a multi-objective parameter inversion method based on dynamic numerical model of High Arch Dam is proposed.