Improving the Seismic Performance of Precast Buildings using Dissipative Devices

This paper investigates a new type of friction damper for improving the seismic performance of precast concrete frame structures. The friction damper is used externally at selected beam-to- column joints of the frame to dissipate energy during severe earthquakes. A simplified model describing the hysteretic behaviour of the friction device was developed and parametric analyses were carried out in order to establish the optimum value of the slip force of the device for the different precast structures. The effectiveness of the dissipative friction device was numerically assessed on different typologies of precast structures by performing nonlinear dynamic analyses. The results of the numerical investigations showed that the introduction of the devices caused an increase of the dissipative capacity of the buildings. The plastic deformation concentrated inside the device, protecting the columns from severe damage. A significant reduction of top displacements was observed and the formation of the plastic hinges at the column base was delayed with respect to the unprotected structures. A moderate increase of the base shear was observed for the buildings protected by friction devices.