A significant correlation between the in-plane (IP) and out-of-plane (OOP) damage propagation of masonry infills (MIs) is frequently observed after strong earthquakes, posing a serious problem as regards vulnerability of public buildings such as schools. The present work is aimed at identifying the effects of different IP and OOP modelling assumptions of MIs on their seismic damage. To this end, the state secondary school De Gasperi-Battaglia in Norcia (Italy), object of monitoring by the Department of Civil Protection since 2000, is investigated for the heterogeneity of infill typologies. The school is composed of a basement and three storeys above ground level, with a reinforced concrete (r.c.) framed structure having a long-shaped rectangular plan. Two typologies can be identified in terms of transverse layout of MIs: (i) double-leaf interior partitions, made of hollow clay bricks; (ii) double-leaf exterior infill walls, constituted by facade solid bricks paired with hollow clay bricks. In addition, partial height infills in the longitudinal direction, due to classroom windows, make the columns susceptible to short column effects. MIs are represented by a five-element macro-model predicting both in-plane (IP) and out-of-plane (OOP) behaviour through a horizontal nonlinear truss and four diagonal nonlinear beam elements, respectively. Stiffness and strength values in the OOP direction are also reduced considering the evolution of the IP damage. Three assumptions are investigated for the behaviour of structural MIs: i.e. elastic both IP and OOP; inelastic IP and elastic OOP; inelastic both IP and OOP. Bare and infilled test structures are subjected to biaxial spectrum-compatible accelerograms, to evaluate the IP and OOP damage levels and effectiveness of the OOP simplified verification proposed by seismic codes.

强烈地震后，经常观察到砌体填充物（MI）的面内（IP）与面外（OOP）损伤传播之间的显着相关性，这对学校等公共建筑的脆弱性构成了严重的问题。本工作旨在确定MI的不同IP和OOP建模假设对其地震破坏的影响。为此，对自2000年以来一直由民防部监控的意大利诺恰市国立中学De Gasperi-Battaglia进行了调查，探讨了填充类型的异质性。该学校由一个地下室和三层以上的地面组成，并由钢筋混凝土（rc）框架结构构成，并具有长形的矩形平面图。根据MI的横向布局，可以确定两种类型：（i）由空心粘土砖制成的双叶内部隔板；（ii）由外墙实心砖与空心粘土砖组成的双叶外墙。另外，由于教室窗户的缘故，纵向上的部分高度填充物使圆柱易于受到短圆柱效应的影响。MIs由五元素宏模型表示，该宏模型分别通过水平非线性桁架和四个对角非线性梁单元预测面内（IP）和面外（OOP）行为。考虑到IP损伤的发展，在OOP方向上的刚度和强度值也会降低。对于结构性MI的行为，研究了三个假设：即IP和OOP都具有弹性；无弹性IP和弹性OOP；IP和OOP都没有弹性。