Feasibility study of low-damage technology for high-rise precast concrete buildings

The research investigates the benefits associated to the application of highperformance hybrid rocking connections for tall buildings. A comparison between conventional (cast-in-situ) monolithic system and a low-damage rocking dissipative system (PRESSS technology) has been carried out in terms of seismic performance and post-earthquake economic losses. The case study building consisted of an 18-storeys tower with a dual structural system designed for high seismic demand. A Direct Displacement Based Design procedure for framewall structures has been implemented and 2D analyses have been performed using lumped plasticity modelling (Ruaumoko 2D). After a calibration of the numerical models using non-linear static analyses (adaptive push-over and cyclic adaptive push-over) spectra compatible accelerograms have been selected to perform non-linear time history analyses. The results proved that PRESSS technology is capable of improving the seismic performance of tall buildings.The presence of post-tensioned unbonded tendons and/or bars into the structural elements in parallel with external dissipaters (Plug&Play) lead to negligible damages and to the absence of post-earthquake residual drifts. Finally, the efficiency of this technology has been further highlighted in terms of post-earthquake losses reduction, such as repair cost and downtime, through the estimation of the Probable Maximum Losses (PML) from an intensity-based. calculation (FEMA P-58 methodology). Considering the relevance of non-structural elements in increasing the economic losses, an integrated solution with both low-damage structural members (PRESSS technology) and façade systems (unreinforced masonry infill walls) has been studied, demonstrating how this building configuration can substantially reduce the expected repair cost and business interruption for tall buildings