The Deformation Analysis Of Low-head Radial-flow Power Station Dam

The safety of hydropower dams has always been one of the hot issues of scientific research and technicians.With the continuous development of basin cascade power stations and the irregular changes of hydrology and water regime,the dam safety problem of low-head radial-flow power station is becoming more and more serious and the deformation analysis and prediction of low-head radial-flow power station dams begin to attract the attention of scholars,but because the dam deformation analysis is a multi-disciplinary edge problem,and in order to improve the deformation analysis method of the low-head radial-flow power station,as well as obtain the deformation law of the dam,the static characteristics of the powerhouse dam section and the sluice dam section,which is the theoretical basis for the dam deformation safety monitoring and prediction system design.The research was carries on in the article.In this paper,the typical bulb tubular hydropower station on the main stream of the Yellow River is chosen as the research object and the 1:1 3D modeling,mess partition and numerical simulation are carried out,combined with the hydraulic model test of the dam and the measured data in actual operation,a comparative study on the deformation of a dam with low-head radial-flow power station is launched.The main contents and achievements of this paper are as follows:1)Based on finite element method(FEM),computational fluid dynamics(CFD)and fluid-solid coupling theory,the dam is numerically simulated according to the characteristics of hydraulic model test.And compared with the observed data of low-head radial-flow power station in operation,the dam deformation analysis method was established for low-head radial-flow power station with comprehensive hydraulic model test,numerical simulation and actual operation observation as the system.2)The deformation size,distribution and cause of dam structure under two extreme operating conditions of check flood and design flood for low-head radial-flow power station are analyzed and forecasted.It can be predicted that: Under the condition of check flood and design flood,considering the action of water load,the reliability of each structure of low-head radial-flow power station dam shows that that the reliability of the upstream guide wall is the lowest,followed by the sluice,and the reliability of the powerhouse is the highest.3)By using the modal analysis function of ANSYS Workbench,the first ten natural frequencies and modes are obtained of the powerhouse and sluice dam section of the low-head radial-flow power station under static mode and considering fluid-solid coupling.By comparing the static mode and the prestress mode of the powerhouse dam section and the flood sluice dam section,it is found that the water load effect has little effect on the modal of the powerhouse dam section of the low-head radial-flow power station,and only the static mode is considered.The effect of water load on the sluice dam section of low-head radial-flow power station is large and the analysis needs to consider the prestress mode,and the key observation of sluice dam section of low-head radial-flow power station during flood peak period is put forward.Modal analysis of low-head radial-flow hydropower station shows that: The resonance risk point of powerhouse dam section is the seventh mode(24.761 Hz),the fifth stage(12.715 Hz)and the ninth stage(23.717 Hz)of flood sluice dam.It provides the theoretical basis for preventing the resonance in operation of low-head radial-flow power station dam.