Study On The Safety Of Protective Structures In Stilling Pool Of High Dam

For some completed large stations, the destructive accidents are usually common for the incorrect design and operation caused by the knowledge shortage for the complexity of bottom stilling basin and arch dam plunge pool stable mechanics. For such reliability problems, this paper has obtained some meaningful conclusions based on the model experiment, theoretical analysis, prototype measurement and finite element analysis (FEA) .Based on the protective structure of hydraulic jump energy dissipation and ski-jump energy dissipation, the stress characteristic, stability mechanics of the horizontal and inverted arch bed plate and slopes are studied ,impact factors of energy dissipation are analysed, analysis method of the protective structure of hydraulic jump energy dissipation is formulated, the main control measures of prototype experiment are advanced, the physical model and numerical calculation methods for the structural dynamic response are also been discussed.On the basis of the anti-buoyancy stability criterion, the stability model and influencing load of the flat-bottom bed for different working condition are analysed. And the load characteristic is also discussed. Based on the study of the Yutang Hyropower Station, fracture patter, a new pattern for the bed plate, is introduced by the FEA method, which is focused on the effect that the thickness of bottom bed and prestressed anchor affect fracture or turnover. The experimental feedback analysis for he basic destructive reason of the Wuqiangxi Hyropower Station is processed.The integral stability and partial stability mechnics of inverted arch bed plate are detailedly formulated. Based upon physical model and theoretical analysis, the result shows that the inverted arch bed plate is better than the flat-bottom bed. By experimented with geometrical parameters, such as the inverted arch curvature &(and)block dimension, the effect behaviour that curvature and block dimension affect ultimate resistance is deduced. Based upon the Changtangang Hydropower Station , the paper provides details of safety reliability of the inverted arch plunge pool by design analysis, prototype observation and nonlinear FEA. The results of the observation and calculation shows the methods that the contact model simulated interaction effect of the plate-abutment, plate-bedrock is feasible ,and the nonlinear spring element simulated, the cohesion and slipping interaction effect between the bedrock and anchor bar are feasible too. Based upon the model test, the hydraulic characteristic of the pervious bed plate is primarily studied, and The effect that coefficient and hole's diameter of permeability affect uplift pressure and arch abutment thrust are studied, which draws a conclusion that the pervious plate can obviously reduce the hydrodynamic load and greatly reinforce the stability of the protective structure.This document also does some partial research on the conformation of bank paving without bottom protection type plunge pool, which shows it can effectively reduce the concentration energy on bank slope, the hydrodynamic load that by the width of the jet impacted zone is properly broadened, so that the reliability of the slope protection can be improved.At last, based upon the plunge pool construction of the Ertan Hyropower Station, combined with the model test and prototype measurements, used the advanced monitoring techniques,adopted pattern recognition, fuzzy assessment and mutation theory, focused upon the dynamic displacement index, the safety real-time safety monitoring warning system on the protective structure is developed.