地下结构柔性支护地震动响应特性研究

Flexible supports are widely used for caverns of underground powerhouse. Currently flexible supports are mostly designed according to the static state by engineering analogy methods, whose effects during seismic response are in need of theoretical guide and relevant research. Most large underground powerhouses in our country are located in the earthquake-prone southwest region. Thus research on seismic response for flexible support of underground structure is of significant meaning for the safety evaluation theory on working of underground powerhouse. On the basis of design data of each power station already built and with field investigation, experimental simulation, theoretical analysis, numerical computation adopted, the combined action mechanisms of surrounding rocks and flexible support are analyzed and dynamic combined action models are established. Refraction and reflection of seismic wave in rock with flexible support are examined and dynamic damage evolution law for flexible support and rocks are studied. High efficient finite element parallel computation methods are studied and high efficient computation platform for seismic response of flexible support for underground structure is implemented. The time dependent and dissipated energy accumulation and mutation theory for seismic response are studied and safety evaluation system for flexible support of underground structure is established. Theoretical guidance and technical support for dynamic safety running and lifetime evaluation of large underground powerhouse can be offered through the research. The research results are not only of great theoretical importance, but also be very instructive for engineering design.

地下厂房洞室一般采用柔性支护。目前柔性支护都是采用工程类比法按静力状态设计，其地震动响应的影响缺乏理论指导和相应研究。我国大部分大型地下厂房建在地震高发的西南地区，研究地下结构柔性支护地震动响应特性，对地下厂房运行的安全评估理论具有重要意义。本项目依托已建大型地下厂房设计资料，采用现场调查、实验模拟、理论分析、数值计算等手段，研究围岩与柔性支护地震动响应联合作用机理，建立围岩与柔性支护动力联合作用模型；研究柔性支护岩体地震波折射、反射波叠加特性，分析柔性支护结构和围岩动响应损伤演化规律；研究高效有限元并行计算方法，开发地下结构柔性支护地震动响应高效计算平台；研究地震动响应的时效和耗散能累积突变理论，建立地下结构柔性支护地震动响应安全评价体系。通过研究，为大型地下厂房的抗震安全运行和生命周期的评估提供理论依据和技术支持。该项研究成果不仅具有重要的理论意义，对工程设计也具有重大的指导意义。

我国水利水电大型地下厂房多建在地震高发的西南地区，研究地下结构柔性支护地震动响应特性，对地下厂房运行的安全评估具有重要意义。本项目依托已建大型地下厂房设计资料，采用实验模拟、理论分析、数值分析相结合的研究方法，研究地下结构柔性支护的地震动响应特性，围绕柔性支护的作用机理、力学模型、地震动响应、高效算法和安全评价等方面展开研究。经历四年的努力，取得的主要成果有：（1）基于柔性支护加固围岩的作用机理，建立了锚杆的复合锚固单元模型，揭示了地震动荷载在围岩与柔性支护的相互作用机理。建立了锚杆和围岩协同变形的力学模型，建立了考虑锚杆沿程应力、锚杆受剪切作用和岩锚吊车梁涂沥青段的数值分析模型。（2）提出“开源节流”的高效计算优化思路，构建了基于计算机集群和CPU/GPU异构的高效并行平台。针对柔性支护与围岩的相互作用特性，构建地下洞室柔性支护抗震计算数值分析平台。（3）研究了地震作用下锚杆应力的响应过程，及锚杆和围岩的接触界面、锚头界面的损伤过程，揭示地震灾变中柔性支护和围岩的损伤演化规律。（4）研究了不同的锚固参数组合下，柔性支护的地震动破坏机制、破坏过程及破坏形式，揭示了柔性支护加固围岩的抗震机理，提出了柔性支护抗震设防的建议。.在本项目资助下，在《Computers and Geotechnics》、《Soil Dynamics and Earthquake Engineering》、《Shock and Vibration》、《岩石力学与工程学报》、《岩土力学》等期刊上发表学术论文22篇，其中SCI收录8篇，EI收录14篇。培养博士研究生13人，硕士研究生15人。取得的相关研究成果完善了地下结构抗震计算基本理论，同时为地下结构柔性支护的抗震设计提供理论支撑。