Experimental implementation of the nonstructural element simulator on shake table (NEST) for an archetype tall building

Abstract

Nonstructural damage, usually predominates in buildings subjected to low to moderate seismic intensities and contributes significantly to business interruption and economic losses. It promotes a rapidly growing need for experimental research and qualification of various types of nonstructural elements in buildings in the recent decades. To provide a novel option of experimentally simulating the realistic boundary conditions for various nonstructural elements in labs, we developed the Nonstructural Element Simulator on Shake Table (NEST), a passively controlled three-layer substructural testbed driven by existing shake tables. This paper presents the first experimental implementation of NEST on a challenging 42-story archetype tall building. The dynamic properties of the substructure were tuned to adapt the archetype building and the required shake table motions were solved as a reverse problem by an open-loop control algorithm. The test results proved the capability of NEST to replicate the history responses of the target floors in the archetype building under either recorded earthquake ground motion or artificial loading protocols for qualification purposes. In all cases, the synthetic relative error in the floor accelerations and the inter-story drift within the frequency range of interest was less than 5% in the numerical domain and less than 30% in the physical realization. The seismic responses of a variety of nonstructural elements to the substructural motions show that, in the mid-story of the archetype tall building, the ceiling sustained minimum damage because of the small floor acceleration while the indoor contents slid significantly and even overturned.