PSI - Issue 78

Giulia Giuliani et al. / Procedia Structural Integrity 78 (2026) 929–935

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a) b) Fig. 3. Horizontal response spectra in terms of a) pseudo-acceleration and b) displacement.

Fig. 4. a) Vertical response spectra in terms of pseudo-acceleration and b) V/H ratio.

3.2. Effects on Structural Typologies Since the axial stiffness of masonry walls and reinforced concrete (RC) columns is typically high, their vertical vibration periods are very short. As a result, when exposed to near-fault earthquakes, these elements may experience complete unloading. For structural systems that cannot resist tensile forces, such as masonry or precast RC buildings without mechanical beam-to-column connections, this unloading can eliminate friction forces, causing a loss of horizontal resistance. Consequently, both local and global collapse may occur, as reported for masonry structures