Retrofitting Alternatives for Pavia’s Cathedral

Abstract

The collapse of the 800-year-old Civic Tower of Pavia in 1989 caused severe damage to the adjacent Cathedral, which stood 4 m away. The Cathedral itself, believed to be one of the most important works by Bramante, was already in a deteriorating condition because of an overall fracture of the eight, very slender, main marble pillars. The church is an imposing building 92 m tall, with one of the largest existing masonry domes (30 m in diameter Fig. 1). The masonry dome had begun to exhibit large fractures and serious damages to the pillars had become visible over the last two centuries (Fig. 1b). Few years of historical studies, testing, monitoring and finite element analyses revealed that the damage was due to two different independent distresses. The structural assessment was very useful in separating the intervention into two parts and, thus, into two successive periods of works. This paper discusses four available alternatives for the retrofitting, and suggests an innovative technique for the strengthening of the pillars on site, leaving in place the entire historical structure, as required by the most recent criteria of Monument Conservation.