【作者】 刘石；

【导师】 佴磊； 尹新生；

【作者基本信息】 吉林大学 ， 地质工程， 2013， 博士

【摘要】 近几十年，大型水电站发展迅猛，水电结构体型巨大，又多处在地震活动比较活跃的西南和西北地区，地形地质、水文气象情况比较复杂，利用成熟的计算方法和试验结合结构的实际条件进行受力情况、使用情况分析是建设过程中必不可少的一个环节，而水电这类投资大运行周期长的关乎国家经济和民生的特大建筑，建成后其正常荷载下的性能监测和超常规及突发荷载下的可能性损伤评估等相关研究和工作已受到越来越多的关注和重视，并已不局限于研究领域而是与实际工程进行结合，意义深远重大。对大体积水工混凝土结构进行动力分析，混凝土材料的性能、结构抗力、损伤识别及损伤参数的选取等研究相对现有的水工结构力学计算方法、理论的发展不相适应，也影响到大体积水工结构的分析结果的准确性，严重制约对结构动力分析的进一步深入研究及水电站结构安全性评价的整体可靠性和精度水平。本文的研究对象是双曲拱坝，依据水工混凝土配合比特点制定试验方案，对混凝土进行单轴抗压试验，分析不同混凝土配合比和外加剂情况下混凝土应力应变全曲线、混凝土抗压强度及混凝土的弹性模量、泊松比的特点，在对混凝土静动态破坏准则研究现状进行综述分析的基础上，提出适用于水工混凝土材料的两段式单轴压缩准静态本构模型，根据混凝土单轴压缩试验结果对混凝土材料的应力应变曲线的上升和下降段做出修正，从而提出基于不同配合比和原料的混凝土单轴压缩本构模型。在对坝体结构进行有限元非线性分析时，在Willam-Warke准则的基础上，并采用Haigh-Westerguard坐标系提出了一种四参数准则作为混凝土破坏准则，因为不同坝所使用的混凝土都是经过特殊设计而配比的，具有唯一性和特殊性，所以不匹配通用的混凝土材料数据，而该准则参数可由基本材料试验得到的各项强度数据来确定，本文提出此准则并编制相应子程序，在输入相关混凝土基本强度数据后据此准则进行结构分析，以期得到与实际情况更相符的结果。在混凝土静态破坏准则的基础上，针对温度场、坝内水体和坝体地基这些可变荷载，编制有限元分析子程序，在混凝土刚度矩阵和质量矩阵中叠加影响因子，构建混凝土动力分析的方程，加入适用于坝体混凝土材料的破坏准则和屈服，进行结构的有限元动力分析，与同结构的试验进行验证。对双曲拱坝进行损伤分析，选用适当的具备敏感度的损伤指标，研究人工神经网络方法进行坝体损伤识别的可行性和可靠度，研究考虑大体积混凝土弹性模量硬化及基础取用范围变化所带来动力特征的改变是否对损伤识别结果造成误判，研究结果表明人工神经网络适用于水坝结构的损伤识别，并且对振型和自振频率模态参数识别程度较高，误判程度很小。更多还原

【Abstract】 In recent decades, the development of large-scale hydropower stations is rapid,the great-size structures are most in Southwest and Northwest regions with activeseismic activities, where topographic and geological, hydrological andmeteorological situation is more complex, using sophisticated calculation methodsand test binding actual conditions by King Architectural usage analysis is anessential part in the process of building, such hydropower stations with largeinvestments and long-run cycle are in relation to the national economy and people’slivelihood, after the completion, performance monitoring within normal load and thestudy and work on possibility of damage assessment within unconventional burstloads are being more and more concerned and intentioned, and not limited toresearch areas, but combined with actual engineering, the meaning is far-reachingand significant. To the dynamic analysis of hydraulic concrete structure in largevolume, the research on performance of concrete material, structural resistance,damage identification and selection of damage parameters is incompatible relativelyto the existing hydraulic structural mechanics calculation methods and thedevelopment of the theory, it’s also affect the accuracy of the results of large-volumehydraulic structures, severely restricting further and deeper research on structuraldynamic analysis and the overall reliability and accuracy levels of hydropowerStructural Safety Assessment. The object of this paper is the arch dam, according tothe hydraulic concrete mixture ratio characteristics to develop pilot programs, thenoperate an uniaxial compression testing of concrete subject, analysis concretestress-strain curve of different concrete mix ratio and admixtures, the characteristicsof the compressive strength of concrete, the modulus of elasticity of concrete andthe Poisson’s ratio, based on the summarized analysis of the concrete in static anddynamic failure criterion Research, proposed a two-stage hydraulic concretematerials uniaxial compression quasi-static constitutive model based on The concrete uniaxial compression test results to make a correction to the segment of therise and fall of the stress-strain curve of concrete materials, then proposedconstitutive model based on different mixing ratio and raw concrete uniaxialcompression. For nonlinear finite element analysis of the dam structure, based on theWillam-Warke guidelines and the Haigh-Westerguard coordinate system, afour-parameter criteria as concrete failure criterion is proposed, because differentdam concrete ratio is specially designed with the uniqueness and particularity, so thedata does not match the common concrete material, the criteria parameters aredetermined by the strength of the basic material testing data, this paper presents theguidelines and propagate the corresponding sub-program, structural analysisaccordingly this criteria will work after the entering of concrete strength data, inorder to get the results more consistent with the actual situation. based on concretestatic failure criterion considered variable load such as the temperature field, thewater in the dam and the dam foundation, the preparation of the finite elementanalysis concludes subroutine stack concrete stiffness and mass matrices ImpactFactor, building concrete dynamic analysis equation joined failure and yield criteriafor dam concrete materials, the dynamic finite element analysis of structure canwork, then dong the verification test with the same structure. Analysis hyperbolicarch dam damage, with selection of sensitivity injury indicators appropriate, thefeasibility and reliability of artificial neural network method for dam damageidentification is studied, the study took into account a range of bulk elastic modulusof concrete hardening and the changes of basic access whether brought aboutmisjudgment of damage identification results by the change of the dynamiccharacteristic, the study results show that the artificial neural network can be appliedto the dam structure damage identification, and the method is in higher degreeidentification with the modal parameters such as shapes and the natural vibrationfrequency of structure, and misjudgment is less.更多还原