Advanced Wood-Based Solutions for Mid-Rise and High-Rise Construction: Structural Performance of Post-Tensioned CLT Shear Walls with Energy Dissipators
The latest developments in seismic design philosophy have been geared towards developing of so called "resilient" or "low damage" innovative structural systems that can reduce damage to the structure while offering the same or higher levels of safety to occupants. One such innovative structural system is the Pres-Lam system that is a wood-hybrid system that utilizes post-tensioned (PT) mass timber components in both rigid-frame and wall-based buildings along with various types of energy disspators. To help implement the Pres-Lam system in Canada and the US, information about the system performance made with North American engineered wood products is needed. That information can later be used to develop design guidelines for the designers for wider acceptance of the system by the design community.Several components influence the performance of the Pres-Lam systems: the load-deformation properties of the engineered wood products under compression, load-deformation and energy dissipation properties of the dissipators used, placement of the dissipators in the system, and the level of post-tensioning force. The influence of all these components on the performance of Pres-Lam wall systems under gravity and lateral loads was investigated in this research project. The research project consisted of two main parts: material tests and system tests.
New Zealand Society for Earthquake Engineering Conference
Research Status
Complete
Notes
April 13-15, 2012, Christchurch, New Zealand
Summary
The Nelson Marlborough Institute of Technology Arts and Media building was completed in 2011 and consists of three seismically separate complexes. This research focussed on the Arts building as it showcases the use of coupled post-tensioned timber shear walls. These are part of the innovative Expan system...
New Zealand Society for Earthquake Engineering Conference
Research Status
Complete
Notes
April 13-15, 2012, Christchurch, New Zealand
Summary
Driven by sustainability, locally available resources and expertise, and economy, the design of the Carterton Events Centre focused on timber for the majority of the main structural and non-structural components. Combined with a client desire for minimization of earthquake damage, dissipative post-tensioned rocking...
The controlled rocking heavy timber wall (CRHTW) is a high-performance structural solution that was first developed in New Zealand, mainly considering Laminated Veneer Lumber (LVL), to resist high seismic loads without sustaining structural damage. The wall responds in bending and shear to small lateral loads, and it rocks on its foundation in response to large seismic loads. In previous studies, rocking has been controlled by both energy dissipation elements and post-tensioning, and the latter returns the wall to its original position after a seismic event. The controlled rocking response avoids the need for structural repair after an earthquake, allowing for more rapid return to occupancy than in conventional structures. Whereas controlled rocking walls with supplemental energy dissipation have been studied before using LVL, this thesis proposes an adapted CRHTW in which the design and construction cost and complexity are reduced for low-to-moderate seismic hazard regions by removing supplemental energy dissipation and using cross-laminated timber (CLT) because of its positive economic and environmental potential in the North American market. Moreover, whereas previous research has focussed on direct displacement-based design procedures for CRHTWs, with limited consideration of force-based design parameters, this thesis focusses on force-based design procedures that are more common in practice. A design and analysis process is outlined for the adapted CRHTW, based on a similar methodology for controlled rocking steel braced frames. The design process includes a new proposal to minimize the design forces while still controlling peak drifts, and it also includes a new proposal for predicting the influence of the higher modes by referring to previous research on the capacity design of controlled rocking steel braced frames. Also, a numerical model is outlined, including both a baseline version and a lower-bound model based on comparison to experimental data. The numerical model is used for non-linear time-history analysis of a prototype design, confirming the expected performance of the adapted CRHTW, and the model is also used for incremental dynamic analyses of three-, six-, and nine-storey prototypes, which show a low probability of collapse.
New Zealand Society for Earthquake Engineering Conference
Research Status
Complete
Notes
April 27-29, 2017, Wellington, New Zealand
Summary
With global urbanization trends, the demands for tall residential and mixed-use buildings in the range of 8~20 stories are increasing. One new structural system in this height range are tall wood buildings which have been built in select locations around the world...
Timber as a primary structural material has been forced to continually evolve to keep abreast with the changing demands of the construction industry. This paper presents further research undertaken by Queen’s University Belfast to evaluate the advantag...
