Modelling and Seismic Response Analysis of Existing Italian Residential RC Buildings Retrofitted by Seismic Isolation

The Use of SMAV Model for Computing Fragility Curves

“…The amount of structures that were not designed to withstand earthquakes makes fundamental to establish reliable and low computationally demanding strategies for evaluating damage scenario at large or urban scale. This article presents a simplified SMAV-based framework for the evaluation of fragility curves applied to multi-storey correlate the periods to the number of floors ([0.1, 0.5] sec for buildings with 1, 2 or 3 floors, [0.4, 0.8] sec for buildings with 4, 5 or 6 floors, [0.7, 1.1] sec for buildings with more than 6 floors or base isolated [41][42][43]) an accurate experimental estimation of the first natural frequency (or period) is strongly suggested. This aspect is considered fundamental in terms of reliability of the result.…”

“…It can therefore be said that the best parameter for measuring the seismic intensity IM for the construction of fragility curves is the integral parameter ASI measured in the interval of the periods of interest. 1] sec for buildings with more than 6 floors or base isolated [41][42][43]) an accurate experimental estimation of the first natural frequency (or period) is strongly suggested. This aspect is considered fundamental in terms of reliability of the result.…”

“…This aspect leads us to advise against the construction of fragility curves in Saavg especially for low However, it is worth to nothing that the three intervals are only a general interpretation of the first period of the structures. Even if other authors suggest to correlate the periods to the number of floors ([0.1, 0.5] s for buildings with 1, 2 or 3 floors, [0.4, 0.8] s for buildings with 4, 5 or 6 floors, [0.7, 1.1] s for buildings with more than 6 floors or base isolated [41][42][43]) an accurate experimental estimation of the first natural frequency (or period) is strongly suggested. This aspect is considered fundamental in terms of reliability of the result.…”

Seismic reliability of Italian code‐conforming bridges

“…As per the multidirectional bearings, their behaviour is in principle frictional with three increasing levels of friction: up to a displacement corresponding to the attainment of a contact pressure of 60 MPa, $$d_e$$, the friction coefficient, μ e , can be taken equal to the nominal value for PTFE‐stainless steel friction under service conditions (in the order of 1%); once $$d_e$$ is exceeded, the friction coefficient increases to μ 1 , which can be taken equal to 1.3$${\mu }_e$$, based on experimental results 63 ; this is still a low value, corresponding to a stage where nominal displacement capacity is exceeded and contact pressure is increasing above maximum design levels, but there is still contact between the sliding surfaces; as horizontal displacement further increases, the contact surface between PTFE and stainless steel reduces until it can be deemed to be lost, for a displacement d 1 herein assumed equal to (D + C)/2, where D is plate width and C is the bearing pot diameter. In this last stage, reference to the steel‐concrete friction coefficient μ 2 can been made, reflecting sliding of the upper plate on the concrete pier cap.…”

Mechanical model of the over-stroke displacement behaviour for double concave surface slider anti-seismic devices

“…To describe the over-stroke behaviour of the DCCSS bearing, the SingleFPBearing element (Mckenna et al, 2000), providing a fixed bottom node (i-node) and a top node (j-node), was modified by adding three zero-length parallel hinges between the j-node and an external fixed node (k-node in Figure 9), as already discussed in other studies (Di Cesare et al, 2019Ponzo et al, 2020;Ponzo et al, 2021;Cardone et al, 2022). In Figure 9 the resulting sloping dog bone shape for the constitutive law is shown with the main characterizing parameters, such as capacity displacement d c and force F c .…”