1,721,040 research outputs found
Assessment of the effectiveness of repair and retrofitting techniques using SCC and CFRP on damaged r.c. bridge piers
No full textPseudo-dynamic tests for seismic analysis of repaired and strengthened r.c. bridges using opensees
No full textPseudo-dynamic tests on reinforced concrete bridges repaired and retrofitted after seismic damage
No full textThis research studies the seismic behavior of repaired and seismically upgraded reinforced concrete bridges that were severely damaged after an earthquake. These bridges were designed according to the previous Italian Code (1986) which did not include capacity design rules and proper construction details. Pseudo-dynamic tests were performed on these bridges by means of in-house test apparatus. Seismic actions similar to those used for undamaged bridges were applied. A repaired and retrofitted specimen in a 1:6 scale of the most stressed pier was tested physically in the lab while the rest of the bridge was simulated numerically. The scale factors of the pier specimens guarantee a global similitude to resisting shear and moment, confinement, buckling of longitudinal rebars and anchorage behaviour. The specimens were repaired through use of epoxy adhesive, stainless steel rebar parts, self-compacting concrete and strengthened with C-FRP wrapping. Finally the seismic behavior of the repaired and retrofitted bridge was compared to that of an Italian built bridge and to a bridge designed according to Eurocode 8 for the seismic design of bridges, both tested in previous researches. Conclusions on the overall behaviour were positive and recommendations for the improvement of some repair and retrofitting techniques are illustrated for future application and investigation
Pseudo-dynamic testing of repaired and retrofitted RC bridges
No full textPseudodynamic tests on repaired and retrofitted bridges piers have been performed. More specifically, one repaired and retrofitted pier specimen is physically tested, white the rest of the bridge is numerically simulated using an in-house test apparatus. Techniques for repairing and retrofitting of the most stressed r.c. circular piers of a bridge designed according to Italian Code before 1986 severely damaged after previous pseudodynamic and cyclic tests, are described. The specimens, in scale 1:6, have been repaired using epoxy adhesive, stainless steel rebars, self compacting concrete (SCC), strengthened with carbon fiber reinforced polymer (CFRP) wrapping and then tested again by pseudodynamic tests, under the seismic action used for first tests on undamaged specimen. Some considerations on sustainability for seismic repairing and upgrade of r.c. bridges are given. Finally, the seismic behaviour of the retrofitted bridge piers has been compared to the seismic behaviour of the original piers and to numerical results of a detailed fiber model built in OpenSees
Experimental Evaluation of Bridge Piers Repaired After Previous Seismic Pseudodynamic Tests
No full textModified Monti-Nuti model for different types of reinforcing bars including inelastic buckling
No full text
Dynamic monitoring and model updating of the Leaning Tower of Pisa
No full textThe Leaning Bell Tower of Pisa (Italy) – built between 1173 and 1370 – is included within the list of the World Heritage Sites by UNESCO since 1987. In the past years, the Tower and the underlying soil have undergone many interventions in the attempt to reduce and stop definitely its inclination. The Tower was also equipped with a sensor network in-tended for seismic monitoring, which recorded the dynamic response of the monument un-der some far-field earthquakes. In this study, the dynamic response of the Tower recorded under some recent seismic event has been analyzed in the time- and frequency-domain, thereby allowing the identification of its main vibration modes. Furthermore, a simplified finite element model of this valuable monument has been developed taking into account the soil-structure interaction. This numerical model has been used to perform a large sensitivity analysis and to calibrate the dynamic impedances at the base of the structure. The results of the dynamic analyses performed using the seismic input evaluated on the ground surface by means of a seismic hazard assessment and the local site response analysis are finally pre-sented and discussed
- …
