SAFETY MEASURES APPLICATION TO THE CHURCH OF SAINT MARY OF VISITATION PLACED IN COMUNE DI CASCIA, DAMAGED BY THE EARTHQUAKE OCCURRED ON THE 24TH OF AUGUST 2016 AND SUBSEQUENTLY DECLARED AS CONDEMNED BY THE GOVERNMENT ORDER N.177
Owing to the earthquake that had affected the central Italy area on the 24th of August 2016, Krea Costruzioni was selected to secure the church of Saint Mary of Visitation, which was declared as condemned by the government order n. 177.
Firstly called Saint Mary of Plebs and then transformed into a collegium, Saint Mary of Visitation was surely one of the most important churches in Cascia, also because of the building that dates back to the period previous the 1000 A.D.
It is noteworthy the altar painting representing the Peace among Cascia’s inhabitants, painted in 1547 (removed by firefighters as prevention), along with several frescos painted between the end of the XIV century and the beginning of the XV century.
The church displayed a quite complicated outline, as many vertical and sub-vertical wall cracks concentrated on the right side of the main wall and on the both lateral sides of the Holy Sacrament Chapel. It was particularly notable the crack outline occurred on the right side of the main wall, where deep diagonal gaps displayed a separation and a turning movement of the wall toward the bottom, which was a clear sign of a rollover mechanism.
On the main wall, beside the detachment between the wall and the vaults above, it is also evident the enlargement occurred to the top of the wall, which was caused by the effect of the inadequate conjunction between walls and ceilings applied to the structure when it was being built.
The whole intervention aimed at some goals:
- The preservation of public and private safety
- The preservation of the structure
- The possibility for people and vehicles to transit pass the southern-eastern side of the building
- The possibility for people to get back in their houses overlooking the northern-eastern side of the church
To reach these goals, the intervention has resulted in using indoor linkages in place of outdoor propping devices, which would have closed to passengers the possibility to use the street out of the church. This system took advantage of the load-bearing power of the church walls.
The whole work was based on the use of linkages and propping devices place inside the building. The propping devices used were Gewi bars made of 500/550 steel and strands made of Warrington Seale steel ᴓ16 ᴓ12. The restraint devices and weigh sharing devices were made by the S355JR type, as HEA and UPN, all thickened by C24 spruce wood.
To protect workers’ safety, it was supplied a structure made out of plastic pipes with a wooden bridging placed above, to provide a safe causeway to allow operators to accomplish the intervention and have a safe access to the internal premises of the church.