基于体外预应力简支技术的混凝土结构整体加固抗震性能研究

The structural retrofit is one of the effective ways to save social resources. Among the retrofit approaches, external prestress reinforcement technology has its unique advantage. According to the main influencing factors for the performance of overall retrofit, external prestress simply-supported reinforcement technology and the idea of adjusting the bending moments at beam ends actively are proposed for enhancing the bending capacity at beam ends relatively and creating the conditions for overall retrofit. First, the boundary conditions of beam-cable combination element are defined and their mechanical models are built respectively. Second, taking geometric nonlinearity and material nonlinearity into account, the deformation compatibility mechanism of beam-cable combination element will be analyzed and its analytical model will be built and validated experimentally. Third, the analytical model of beam-cable combination element will be embedded in the general finite element software to obtain the specialized software for analyzing the seismic performance of overall-retrofitted reinforced concrete structures, the distribution characteristics of internal forces of multi-storey and tall reinforced concrete structure retrofitted by external prestress simply-supported reinforcement technology under earthquake inputs will be investigated via numerical analysis and experimental verification, this project can contribute to providing theoretical basis and analytical methods for the overall retrofit design of multi-storey and tall reinforced concrete structures.

结构加固是节约社会资源的有效途径之一，体外预应力技术具有独特的结构加固优势。课题通过分析整体加固结构性能的影响因素，根据加固技术的特点，合理的选取参数，拟用体外预应力简支加固技术和梁端弯矩主动调幅的思想，实现梁端抗弯能力相对加固，为钢筋混凝土结构整体加固理论分析创造条件。1）确定梁-索组合单元的边界条件，分别建立其力学模型；2）考虑结构几何非线性和材料非线性，分析体外预应力梁-索组合单元变形协调机理，建立理论分析模型，并对模型进行试验验证；3）把梁-索组合单元理论模型嵌入在通用有限元分析软件中，创建钢筋混凝土结构整体加固理论分析的新方法，通过理论分析与试验验证相结合，研究地震作用下多高层钢筋混凝土结构体外预应力简支加固技术整体加固的结构内力分布规律，为多高层钢筋混凝土结构整体加固设计计算和理论分析提供依据和手段。

本项目通过分析整体加固结构性能的影响因素，根据加固技术的特点，合理选取参数，运用体外预应力简支加固技术和梁端弯矩主动调幅的思想，实现了梁端抗弯能力相对加固，为钢筋混凝土结构整体加固理论分析创造了条件。首先分别建立了梁-索组合单元的力学模型，考虑了几何非线性和材料非线性，通过分析体外预应力梁-索组合单元变形的协调机理，建立理论分析模型，并通过试验对其模型进行验证。然后把梁-索组合单元理论模型嵌入通用有限元分析软件中，通过理论分析与试验验证相结合，为多高层钢筋混凝土结构整体加固设计计算和理论分析提供了依据和手段。