Base isolators are effective tools to favor a high level of building performance under lateral load, providing protection to both structural and nonstructural elements. In this context, this paper discusses the possibility of employing materials with different frictional properties to enhance the response of flat and curved‐surface base isolators. Two innovative devices, referred to as “BowTie” and “BowC,” are introduced and discussed in some detail. A series of nonlinear time history analyses are then conducted using a customized computer program and considering a number of case study structures, designed applying a displacement‐based approach. The results of the analyses are used to discuss the key differences between variable friction and constant friction sliding isolation devices. It is shown that the newly proposed isolators may represent an improvement on classic base‐isolation solutions, in light of their higher energy absorption capacity, which contributes to significantly enhance their performance.

Variable friction systems (VFS) have recently been proposed as potential alternatives to traditional friction base isolation devices. However, numerical and analytical studies have been limited to the case of VFS characterized by hysteresis with specific values of re-centering stiffness. This paper derives generalized response equations for VFS with arbitrary hysteretic behavior and presents a design approach for such systems. An extensive numerical study is used to validate the design process and to illustrate key differences in the response of VFS as a function of the systems’ properties, providing some suggestions to select the optimal device for a given seismic demand.

Base-rocking walls represent effective lateral load-resisting systems that are capable of achieving high seismic performance. However, while reliable design procedures have been proposed for these structural systems, little to no attention has been dedicated to the integrity of the attached non-structural elements (NSEs). It is evident that desired seismic performance can only be achieved if both structural and non-structural elements are properly designed and built. In order to take a step toward the formation of accurate but simplified methods of quantifying non-structural demands in rocking systems, this work examines the floor spectra on elastic and inelastic case-study structures subject to input ground motions of varying intensity. After identifying the factors that appear to affect the acceleration demands on NSEs, this paper proposes two preliminary simplified methodologies to estimate floor spectra in base-rocking wall buildings. The procedures are tested numerically by comparing predictions with floor spectra obtained from time-history analyses of rocking wall structures of 4- to 12-storys in height. The results demonstrate that both methods perform well. Further validation, extension and optimization of the methods should be performed as part of future research.