PSI - Issue 44

Giorgio Giacomin et al. / Procedia Structural Integrity 44 (2023) 610–617

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Giorgio Giacomin et al. / Structural Integrity Procedia 00 (2022) 000–000

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• Circular C.S.LL.PP. n.7 of 21/01/19 " Instructions for the application of the Update of the technical standards for constructions referred to in the ministerial decree of 17 January 2018 ", hereinafter referred to as the " Circular ". For all that is not adequately covered by NTC18, and provided that it does not expressly contradict it, the following Design and Qualification Guidelines have been applied (in line with what is specified in Chapter 12 of the same NTC18): • CNR-DT 200 R1 / 2013 " Instructions for the Design, Execution and Control of Static Consolidation Interventions through the use of Fiber-reinforced Composites - Materials, reinforced concrete structures and of c.a.p., masonry structures "; • Decree of the President of the Superior Council of Public Works n.220 of 09.07.2015, containing " Guideline for the identification, qualification and acceptance control of fiber-reinforced polymer-matrix composites (FRP) to be used for the structural consolidation of buildings existing "; • Decree of the President of the Higher Council of Public Works No. 293 of 29.05.2019, in revision of the previous technical document, containing " Guidelines for the identification, qualification and acceptance control of fiber reinforced polymer-matrix composites (FRP) by be used for the structural consolidation of existing buildings "; • CNR-DT 215/2018 " Instructions for the Design, Execution and Control of Static Consolidation Interventions through the use of Fiber-reinforced Inorganic Matrix Composites "; • Decree of the President of the Higher Council of Public Works n. 1 of 08/01/2019, containing " Guidelines for the identification, qualification and acceptance control of fiber-reinforced inorganic matrix composites (FRCM) to be used for the structural consolidation of existing buildings ". 4. Knowledge of the structure The first step, in order to assess the seismic vulnerability of the building, was to define the structure in terms of its geometric model, material properties and construction details. Unfortunately, it was not possible to find much in the way of design documentation of the building under examination, so the complete acquisition of information took place through surveys and visual investigations carried out in situ, from which it was possible to detect the geometry of the structure, the characteristics of the materials, the presence of inter-storey kerbs and the quality of the connections of the wall faces. Therefore, in order to be able to carry out a modelling that comes closest to the real model of the building, it was decided to use a knowledge level LC1 which leads to a confidence factor FC=1.35. Table 1 shows the average values of the mechanical strengths, obtained from table C8.5.I of the Circular 21 January 2019, n. 7 C.S.LL.PP., relating to the load-bearing walls that make up the building subject of this work:

Table 1. Reference values of the mechanical parameters of masonry.

f m [N/mm 2 ]

τ 0 [N/mm 2 ]

E [N/mm 2 ]

G [N/mm 2 ]

Type of masonry

1,5

0,025

870

290

Messy stone masonry (pebbles, erratic and irregular stones) Solid brick and lime mortar masonry

3,45

0,09

1500

500

5. Type of intervention

The anti-seismic reinforcement interventions used for the structural consolidation of the building object of this work were the following: • injections of mortar into the wall faces in order to restore the internal continuity of the cracked or disconnected material, allowing to reinforce the wall and improve its behavior on the floor;