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Steel energy dissipators can be combined with mass timber in integrated seismic lateral force–resisting systems to achieve designs with enhanced seismic performance and sustainability benefits. Examples of such integration include the use of mass timber post-tensioned rocking walls equipped with steel energy dissipation devices. This study proposes a solution using buckling-restrained boundary elements (BRBs) with mass timber walls detailed to pivot about a pinned base. This design allows the walls to rotate with minimal flexural restraint, distributing drift demands more uniformly with building height and reducing crushing damage at the wall base. Experimental quasi-static cyclic tests and numerical simulations were used to characterize the first- and higher-mode behavior of a full-scale three-story building featuring a mass timber gravity system and the proposed mass timber-BRB system. Under first-mode loading, the specimen reached 4% roof drift ratio with stable hysteretic behavior and a nearly uniform story drift profile. While residual drifts were nonnegligible due to the lack of self-centering, analytical estimates indicate realignment is likely feasible at the design earthquake level. Under second-mode loading, the specimen exhibited near-linear behavior with high stiffness. Experimental results were corroborated with numerical simulations for the isolated gravity frame, first-mode-like, and second-mode-like loading protocols. It is expected that results from this study will facilitate greater use of mass timber seismic lateral force–resisting systems. 

The Natural Hazards Engineering Research Infrastructure (NHERI) Converging Design project is a collaborative effort between multiple universities and industry entities with the goal of creating a new design paradigm in structural engineering that employs multi-objective optimization to maximize functional recovery while integrating sustainability principles in the design process. The structural design approaches were validated through full-scale shake table testing of a 6-story mass timber structure at the at the Englekirk Structural Engineering Center at University of California, San Diego (NHERI@UCSD) Large High-Performance Outdoor Shake Table (LHPOST6) facility for eventual inclusion in a multi-objective design optimization framework. The shake table testing included three phases. Phase one consisted of a mass timber self-centering rocking wall (SCRW) system with U-shaped flexural plates (UFPs) in both building horizontal directions. Phase two replaced the SCRWs in one principal direction with SCRWs with buckling restrained boundary elements (BRBs) at the first story. Phase three replaced the newer walls from phase two with a resilient steel moment frame and concentric braced-frame (MF/CBF). The data shared includes reports summarizing the testing program, structural drawings, instrumentation setups, and raw data for the series of shake table tests performed during each phase. The data include building responses due to shake table motions simulating scaled historical ground motions and white noise (WN) tests. 

A full-scale, six-story, mass timber building including Mass Ply Panel (MPP) self-centering rocking walls with Buckling-Restrained Boundary Elements (BRBs) was tested at the Large High-Performance Outdoor Shake Table (LHPOST6) at the University of California, San Diego (UCSD). Measured sensor and derived data included global responses, such as floor displacements and accelerations, along with local responses, such as post-tensioning (PT) forces and uplift displacements, among others. The three-dimensional shake table testing program included 23 ground motion records with intensities of shaking ranging from Service (SLE) up to Risk-Targeted Maximum Considered Earthquake (MCER) levels. Results highlighted that: [i] the drift response was near uniform along the height of the building, [ii] the acceleration response included large contributions from the higher modes, [iii] the PT rods remained elastic and had stable post-tensioning force throughout the test program, and [iv] the self-centering system resulted in negligible residual drifts. Qualitative observations from construction and testing were also cataloged to further support the feasibility of implementation in practice. By combining steel BRBs and post-tensioning rods with MPP rocking elements, the system was able to meet the enhanced seismic performance goals targeted for the project. Future work will seek to define both resilience and sustainability targets for designs incorporating multiple performance objectives. 

Advancements in materials, components, and building systems over the past decade have enabled the construction of taller mass timber structures, creating new opportunities for seismic design in mid- and high-rise buildings. This paper presents a systematic comparison of two full-scale shake table test programs-the 10-story NHERT TallWood and the 6-story NHERT Converging Design both conducted at the University of California, San Diego (UCSD) Large High-Performance Outdoor Shake Table (LHPOST). These projects aimed to develop and validate seismic design approaches for wood buildings in high seismic regions. Both structures employed a self-centering mass timber rocking wall system with distributed energy dissipation provided by U-shaped Flexural Plates (UFPs), enabling direct comparison of structural response and design considerations across different building heights. Despite ongoing innovations, many tall timber buildings still rely on concrete cores or steel braced frames for lateral resistance due to a limited number of code- approved timber systems and an industry preference for traditional solutions. This comparative study highlights the performance of timber-based lateral systems under seismic loading and supports their broader adoption in resilient, mid-and high-rise construction. 

To address functional recovery after earthquakes, there is growing interest in developing enhancedperformance seismic-resisting systems. Rocking walls, featuring a base gap-opening mechanism and designed to remain essentially elastic above the base, have demonstrated their potential in various construction materials, including mass timber. If combined with steel energy dissipators, the resulting hybrid steel-mass timber rocking walls have emerged as a promising seismic-resisting system. This study focuses on Post-Tensioned Mass Timber Rocking Walls supplemented with Buckling-Restrained Brace (BRB) boundary elements and builds upon findings from experimental programs funded by the National Science Foundation (NSF) and the United States Department of Agriculture (USDA). The rocking mechanism, controlled by the BRBs and the Post-Tensioned (PT) rods, provides self-centering behaviour, reducing the potential for residual drifts and improving post-earthquake repairability. An estimating method for higher-mode loading profiles is proposed and applied to a six-story archetype, which was tested at the Large High Performance Outdoor Shake Table (LHPOST) at the University of California San Diego (UCSD) in January 2024 as part of the NHERI Converging Design Project. The estimating method is practically formulated to facilitate the implementation in design procedures.