高延性混凝土加固砌体结构破坏机理与抗倒塌设计研究

From the points of improving the seismic performance and collapse-resistant capacity of brick masonry structures，using HDC to strengthen the brick masonry structure is proposed to reduce the seismic damage of brick masonry structures，reduce the cost of post-earthquake rehabilitation，prevent the collapse of the structure and ensure the life safety. In this research project，the seismic performance and compressive behavior of HDC-strengthened brick masonry structures are studied in depth and the influence of mechanical properties of HDC materials on the failure modes，failure mechanism，stiffness degradation and damage tolerance capacity of brick masonry specimens are analyzed. The influence of eccentricity，hight-thickness ratio，different strengthening schemes and the connection between the strengthening layer and masonry on the in-plane stability and collapse-resistant performance of HDC-strengthened brick masonry structures are studied. Considering the strain hardening behavior of HDC materials，a calculation method of shear capacity of the HDC strengthened brick masonry wall is proposed based on compression field models obtained from the bound theorem of plasticity. Due to the contribution of HDC in improving the bearing capacity and deformation capacity of brick masonry walls，thus the seismic fortification level of brick masonry structures is improved to avoid the occurrence of the brittle shear failure in the middle and large earthquakes. The theory and method of performance-based seismic design and collapse-resistant design of HDC-strengthened brick masonry structures are proposed，which provide scientific basis for retrofitting and comprehensive performance improvement of existing brick masonry structures in China.

从提高砌体结构抗震性能和抗倒塌能力的角度出发，提出采用高延性混凝土加固砌体结构，以减轻砌体结构震害，降低震后修复费用、防止结构倒塌和保护生命安全。本项目深入研究高延性混凝土加固砌体结构的抗震性能和抗压性能，分析高延性混凝土力学性能对砌体构件破坏模式、破坏机理、刚度退化和耐损伤能力的影响；考虑偏心距、高厚比、不同面层加固方式和界面连接措施的影响，研究高延性混凝土加固砌体结构的平面外稳定性和抗倒塌性能；考虑高延性混凝土的受拉应变硬化效应，根据塑性下限理论提出基于斜压场分析模型的高延性混凝土加固砌体墙受剪承载力计算方法；考虑高延性混凝土对砌体墙承载力和变形能力的贡献，提高砌体结构的抗震设防水准，保证中震和大震下砌体墙不发生脆性剪切破坏，提出高延性混凝土加固砌体结构的抗震性能设计和抗倒塌设计理论与方法，为我国既有砌体结构的加固改造和综合抗震性能提升提供科学依据。

从提高砌体结构抗震性能和抗倒塌能力的角度出发，提出采用高延性混凝土（HDC）加固砌体结构，以减轻砌体结构震害，防止结构倒塌。本项目中将纤维织物网格与HDC相结合，研究了新组成材料（织物网格高延性混凝土，TR-HDC）的拉伸性能，破坏机理，建立了TR-HDC抗拉强度计算方法及其简化应力-应变关系表达式。深入研究了HDC及TR-HDC加固砌体结构构件的抗压、抗弯、抗剪与滞回性能以及动力荷载作用下HDC加固砌体结构的动力特性，分析了加固材料的力学性能以及不同加固形式对砌体构件破坏模式及破坏机理的影响。基于加固材料优异的力学性能以及加固试件的破坏形态，建立了加固试件的受压承载力计算方法、平面外弯曲荷载作用下的承载力计算方法以及抗剪承载力计算方法，在此基础上，提出了高延性混凝土加固砌体结构的抗震性能设计方法，确保地震作用下加固砌体结构不发生倒塌，为我国既有砌体结构的加固改造和综合抗震性能提升提供科学依据。