During the recent seismic events in Italy (such as L’Aquila 2009, Emilia 2012 and the 2016 Central Italy seismic sequence), several damages and collapses were observed in precast reinforced concrete industrial buildings. Although reliable seismic design criteria are nowadays available for precast frame structures, recent earthquakes showed that the optimal design of the cladding-to-structure connections is yet to be solved. Currently, in the seismic design practice of precast structures, the panels are modeled as additional masses, without any stiffness contribution. Then, the capacity displacement of the designed connection is compared with its demand displacement. This design practice does not correctly reflect the actual behavior of the connection because, due to the configuration of the anchorage devices that exert friction and blockage effects, a force exchange can occur between the panels and the supporting beams. This was demonstrated by the surveys carried out after the seismic events, reporting several damages to traditional anchorage systems. In the context presented above, the research work is aimed at investigating the seismic behavior of the first prototype of an innovative claddingto- structure connection for precast industrial buildings. The innovative device is capable to guarantee higher robustness with respect to the devices currently available on the market, especially when friction forces on the sliding cart are significant and is able to avoid jamming of the cart. Full scale experimental tests are carried out on a prototype precast building equipped with cladding panels. The system is forced by a vibrodyne mounted on the roof and providing an in-plane sinusoidal force along the direction of the panel. Tests are repeated with two different types of connection between the wall panels and the structure: a traditional one and an innovative one, showing the superior performance of the new type of connection in reducing the load transfer and avoiding damage to the panel and the beam even at large excitation levels.
FULL SCALE DYNAMIC TESTING OF WALL PANEL CONNECTIONS FOR PRECAST INDUSTRIAL BUILDINGS
Ilaria Venanzi;Laura Ierimonti;Filippo Ubertini;Annibale Luigi Materazzi;Giuseppe Paci
2020
Abstract
During the recent seismic events in Italy (such as L’Aquila 2009, Emilia 2012 and the 2016 Central Italy seismic sequence), several damages and collapses were observed in precast reinforced concrete industrial buildings. Although reliable seismic design criteria are nowadays available for precast frame structures, recent earthquakes showed that the optimal design of the cladding-to-structure connections is yet to be solved. Currently, in the seismic design practice of precast structures, the panels are modeled as additional masses, without any stiffness contribution. Then, the capacity displacement of the designed connection is compared with its demand displacement. This design practice does not correctly reflect the actual behavior of the connection because, due to the configuration of the anchorage devices that exert friction and blockage effects, a force exchange can occur between the panels and the supporting beams. This was demonstrated by the surveys carried out after the seismic events, reporting several damages to traditional anchorage systems. In the context presented above, the research work is aimed at investigating the seismic behavior of the first prototype of an innovative claddingto- structure connection for precast industrial buildings. The innovative device is capable to guarantee higher robustness with respect to the devices currently available on the market, especially when friction forces on the sliding cart are significant and is able to avoid jamming of the cart. Full scale experimental tests are carried out on a prototype precast building equipped with cladding panels. The system is forced by a vibrodyne mounted on the roof and providing an in-plane sinusoidal force along the direction of the panel. Tests are repeated with two different types of connection between the wall panels and the structure: a traditional one and an innovative one, showing the superior performance of the new type of connection in reducing the load transfer and avoiding damage to the panel and the beam even at large excitation levels.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
