PSI - Issue 11

Natalino Gattesco et al. / Procedia Structural Integrity 11 (2018) 298–305 Gattesco and Boem / Structural Integrity Procedia 00 (2018) 000–000

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In Fig. 7a, a comparison among the capacity curves of the three analyzed configuration is illustrated. In Fig. 7b the resistant ground accelerations are compared: it is observed that in "Case B" a value slightly higher than "Case A" was attained (1.1 times), while in cases "C" and "D", a g,res was equal to 1.9 e 2.7 times that of "Case A", respectively.

(a) (b) Fig. 7. Comparisons of the different analysed configurations in terms of (a) capacity curves and (b) resisting ground acceleration 5. Conclusions Strategies for the reduction of the seismic vulnerability of historical industrial buildings with traditional multi-slope timber roofs, laid on masonry walls along the perimeter and internally on point supports, are investigated in the paper. A simplified numerical method was presented to analyze the effects of a roof bracing by means of nailed wooden based panels ("Case B"), also integrated with the introduction of steel portal frames ("Case C") or with the strengthening of the perimeter walls by means of a mortar coating with composite meshes embedded ("Case D"). For the evaluation of the behavior of the different resisting elements, analytical correlations were proposed. A representative case study was analyzed: with respect to the actual situation ("Case A"), it was observed that the increase in resistant ground acceleration due to the roof bracing only (Case "B") is very limited (12%), due to the premature collapse of the transversal walls. It is therefore necessary to associate this intervention for example with the introduction of steel metal portal frames (Case "C") or with the reinforcement of the walls. Considerable resistant ground accelerations were attained in these cases (0.23 - 0.31 g, respectively). Acknowledgements The financial support of the Department of Civil Protection (Reluis 2017) is gratefully acknowledged. References CSLP - Consiglio Superiore dei Lavori Pubblici. (2009). Circolare 2 febbraio 2009, n. 617. Istruzioni per l'applicazione delle “Nuove norme tecniche per le costruzioni” di cui al decreto ministeriale 14 gennaio 2008, Italy. FEMA 273. (1997). NEHRP guidelines for the seismic rehabilitation of buildings. Washington, D.C. Gattesco. N., Boem, I. (2015a). Seismic performances and behavior factor of post-and-beam timber buildings braced with nailed shear walls, Engineering Structures , 100, 674–685. Gattesco. N., Boem, I. (2015b). Experimental and analytical study to evaluate the effectiveness of an in-plane reinforcement for masonry walls using GFRP meshes. Construction and Building Materials , 88, 94-104. Gattesco. N., Boem, I. (2016). Stress distribution among sheathing-to-frame nails of timber shear walls related to different base connections: Experimental tests and numerical modelling. Construction and Building Materials , 122, 149-162. Gattesco. N., Boem, I. (2017a). Out-of-plane behavior of reinforced masonry walls: experimental and numerical study. Composites Part B: Engineering , 128, 39-52. Gattesco, N., Boem, I. (2017b). Characterization tests of GFRM coating as a strengthening technique for masonry buildings. Composite Structures , 165, 209-222. Gattesco, N., Boem, I. (2017c). Assessment of the seismic capacity increase of masonry buildings strengthened through the application of GFRM coatings on the walls. Int. J. Masonry Research and Innovation , 2(4), 300-320. Magenes, G., Calvi, G.M. (1997). In-plane seismic response of brick masonry walls. Earthquake Eng. and Structural Dynamics, 26, 1091–1112. Sisti, R., Corradi, M., Borri, A. (2016). An experimental study on the influence of composite materials used to reinforce masonry ring beams. Construction and Building Materials , 122, 231–241. Turnsek, V., Cacovic, A. (1971). Some experimental results on the strength of brick masonry walls. 2nd International Brick Masonry Conference, 12-15 April, Stoke on Trent, United Kingdom.