Seismic retrofit of existing reinforced concrete framed buildings often involves both structural members and infill walls. The strengthening of infill walls is mainly aimed at preventing out-of-plane mechanisms and, in some cases, also increases in-plane capacity. On the other hand, the enhancement of the infill's strength might modify the failure mode of the frame, as stated by recent studies. In the case of gravity load-designed buildings, the presence of strong infill walls can lead to brittle failure of columns due to local interaction. This study investigates the effects of the in-plane shear retrofit of infills on the seismic behaviour of reinforced concrete buildings through non-linear dynamic analyses on a three-dimensional infilled frame. The seismic response of the structure is analysed in case of un-reinforced masonry wall and retrofitted wall, considering two types of retrofit. The analysis results are used to calibrate a simplified model aimed at computing fragility curves of reinforced concrete infilled frames and updating existing formulations, in order to account for the properties and the type of the infill. The proposed parameter can be applied in vulnerability assessment studies and for the design of new buildings.

现有钢筋混凝土框架建筑的抗震改造通常涉及结构构件和填充墙。填充墙的加固主要是为了防止面外机制，在某些情况下，还增加了面内容量。另一方面，如最近的研究所述，增强填充物的强度可能会改变框架的失效模式。对于重力荷载设计的建筑物，由于局部相互作用，坚固的填充墙的存在会导致柱子发生脆性破坏。本研究通过对三维填充框架进行非线性动力学分析，研究填充物的平面内剪切改造对钢筋混凝土建筑物抗震性能的影响。考虑两种类型的改造，在未加固砌体墙和加固墙的情况下分析结构的地震响应。分析结果用于校准旨在计算钢筋混凝土填充框架的脆性曲线和更新现有配方的简化模型，以考虑填充物的特性和类型。所提议的参数可应用于脆弱性评估研究和新建筑物的设计。