高碾压混凝土重力坝功能分区结构变形协调机理研究

The sectional interfaces in the functionally sectionalized structures of high RCC (Roller Compacted Concrete) gravity dams usually translate into the weakness of varying degrees due to the change of material properties. Then the problem of deformation incoordination may appear in the dam body, such as high deformation gradient and stress concentration in the interfaces. Defects in the interfacial region would deteriorate, damage and strip gradually during the engineering operation, and they could bring more serious troubles to the dam safety. In this project, the following studies and corresponding methodologies are included: (1) the mechanical properties evolution rules of different concrete materials interfaces in high RCC gravity dam are analyzed by carrying out material and structure tests; (2) the isogeometric analysis numerical simulation method is developed for the refined modeling and high-efficient calculation of the hydraulic structures under the complicated geological conditions; (3) the deformation coordinative behaviors and mechanisms of different sectionalized structures are investigated and revealed, such as HIAC (High-fluidity Impermeable and Anti-Cracking Concrete) - RCC structures and CC (Conventional Concrete) - RCC structures; (4) the optimized design method of the functionally graded dam with the deformation coordination criterions is proposed, which can be effectively used in the actual projects. This research will provide theoretical and technical principles for the lean construction and safe operation of high RCC gravity dams under the complicated environment.

高碾压混凝土重力坝不同功能结构中的分区界面因材料特性变化形成不同程度的弱面，出现高变形梯度和应力集中等变形不协调现象，界面区域的缺陷随着工程运行会逐渐劣化、破坏与剥离，带来严重的安全隐患。本项目通过模型试验研究高碾压混凝土重力坝不同混凝土材料界面力学性能演变规律，开发适合于复杂地质条件下精细建模与高效计算的水工结构数值仿真等几何分析方法，研究揭示高碾压混凝土重力坝上游防渗层高流动防渗抗裂混凝土-碾压混凝土、常态-碾压混凝土分区结构变形协调机理，并结合实际工程研究能够适应变形协调准则的坝体功能梯度结构优化设计方法，为保证复杂荷载环境下高碾压混凝土重力坝的精益建造与安全运行提供新的理论方法和技术支撑。

高碾压混凝土重力坝不同功能结构中的分区界面因材料特性变化形成不同程度的弱面，出现高变形梯度和应力集中等变形不协调现象。为揭示高碾压混凝土重力坝功能分区结构变形协调机理，提出高碾压混凝土重力坝功能梯度结构优化设计方法，主要研究成果包括：(1) 构建了高混凝土坝功能分区结构变形协调指标体系。开展了高流动防渗抗裂混凝土、碾压混凝土和常态混凝土分区材料界面的断裂试验、水力劈裂以及剪切破坏模拟研究，构建了不同分区混凝土界面变形协调评价指标和坝体功能分区界面抗剪强度破坏准则。(2) 开发了水工结构高性能等几何仿真分析平台。建立了含多种岩体、断层、坝区蓄水的复杂水工结构精确等几何模型，充分反映了大坝的精确形体和坝区地形主要特征，实现了复杂水工结构在自重、蓄水多工况下的岸坡稳定分析和坝体应力及变形的精细化分析。(3) 揭示了复杂荷载作用下分区结构变形协调机理。开展了常态-碾压混凝土联合筑坝在施工-运行期的接触界面的相对位移滑动和应力状态；分析了近断层斜入射地震波作用下联合筑坝的变形协调动力响应，探究地震动作用下坝体关键点位移、坝体损伤和结构界面变形协调损伤分布。(4) 提出了耦合等几何与启发式算法的功能梯度分区结构体型优化方法。提高了功能梯度分区结构的整体与局部的变形协调性能；建立了大坝变形安全评价体系，建立了以高混凝土坝多测点长期监测数据为基础的大坝变形交互式时变预测模型。本项目成果应用于乌东德、向家坝、黄登等世界级特大高坝枢纽工程设计、施工与运行中。获天津市科技进步一等奖1项，共发表学术论文48篇（其中SCI收录27篇、EI收录13篇），授权发明专利5项、计算机软件著作权1项，培养研究生10名（其中博士生4名、硕士生6名）。