【作者】 王继敏；

【导师】 练继建；

【作者基本信息】 天津大学 ， 水利水电工程， 2007， 博士

【摘要】 在已建的大型水电站中,作为消能防护结构的底流消力池和拱坝水垫塘,由于对其稳定机理复杂性认识不深,以致设计或运行不当,造成破坏的事件屡见不鲜。本文针对高坝泄洪消能防护结构的安全问题,通过模型试验、理论分析、原型观测及有限元分析相结合对其进行了研究,得出一些有意义的结论。本文从底流消能和挑(跌)流消能防护结构工程问题出发,从水力特性和结构特性两方面综合研究了水平底板、反拱形底板及护坡的受力特性、稳定机理,对影响泄洪消能防护结构稳定的主要因素进行了分析,论述了泄洪消能防护结构的试验研究方法,提出了模型试验的主要控制措施,介绍了物理模型及数值计算两种研究泄洪消能防护结构动力响应的方法。从底板抗浮升稳定准则出发,分析了水垫塘平底板各种工况下稳定模型及影响荷载,并对平底板的荷载特性进行了研究。以鱼塘水电站消力塘底板为研究背景,通过有限元分析方法研究了底板块断裂破坏这一新的破坏模式,着重探讨了底板厚度、锚固钢筋水平对底板断裂或倾覆失稳形式的影响。对五强溪消力池底板的破坏原因进行了试验反馈分析。对反拱底板的整体稳定和局部稳定机理进行了深入分析,通过物理模型和理论分析,得出反拱底板局部稳定条件大大优于平底板的结论。对反拱底板曲率、板块尺寸等体型参数进行了试验研究,得出了底板曲率和板块尺寸对底板极限抗力影响规律。以长潭岗水电站为工程背景,通过设计研究,原型观测及非线性有限元分析,研究证明了反拱型水垫塘的安全可靠性。观测结果与有限元计算结果表明,采用接触模型模拟板块—拱座、板块—基岩之间的相互作用,以及采用非线性弹簧单元来模拟基岩与锚筋之间的粘结滑移作用是可行的,计算结果是可靠的。初步研究了透水底板的水力特性,通过模型试验,对底板各种透水率、透水孔直径对底板上举力和反拱底板拱端推力影响进行了研究分析,得出结论:透水底板能显著减小动水荷载,可大大增强泄洪消能防护结构的安全。本文还对“护岸不护底”水垫塘体型进行了部分研究,得出结论:通过适当扩宽水舌冲击区水垫塘宽度,可有效减小岸坡区冲刷能量集中,减少护坡工程动水荷载,从而达到增强护坡工程安全性目的。最后,以二滩水电站水垫塘工程为背景,结合二滩水电站水垫塘模型试验和原型观测,采用先进的监测技术,应用模式识别、模糊评价和突变理论,以动位移为主要监控指标,开发了泄洪消能防护结构安全实时监控系统。更多还原

【Abstract】 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.更多还原