Charring rate for fire exposed X-Lam

Design of timber structures has been outlined in Eurocode 5. Notional charring rate for softwood and hardwood timber is given. For the performance of X-LAM panels in fire, only little information on charring is available and whether the fire behaviour of X-LAM is similar to homogenous timber panels has not yet been systematically analysed. This paper presents an overview of fire performance of X-LAM and evaluation of its resistance to elevated temperature as an element of structure in comparison to homogeneous timber panels. Numerical study has been carried out based on available experimental results. Charring rates for X-LAM panels obtained from experimental results are compared with those obtained from Eurocode 5 and proposed simplified model

Validation of seismic design parameters for wood-frame shearwall systems

A methodology for assessment of seismic design parameters for a wood-frame shearwall system is developed, consisting of a test program of shearwalls and the application of nonlinear time history analyses to a four-storey wood-frame building that was designed to resist the seismic requirements for Vancouver, British Columbia. Analyses employed 22 selected earthquake accelerograms that were scaled upwards until an ultimate peak ground acceleration (A(u)) was reached where the shearwall reached a "near-collapse" state. The 22 values of A(u) were found to be greater than the "design" peak ground acceleration, indicating the adequacy of the current design procedures for the particular shearwalls investigated. The influence of gypsum wallboard on the behaviour of the shearwalls was also evaluated, and a new force modification factor "R" for walls composed of a mixture of wood-based and gypsum panels was proposed. The effect of flexibility of floor diaphragms was considered separately for a symmetric building and was found to have 5-30% reduction on the A(u) values obtained for the rigid diaphragm case

Seismic performance of moment resisting timber frames

An overview of research findings regarding the seismic performance of moment resisting timber frames is presented. Particular emphasis is given to the evaluation of the Action Reduction Factor (ARF) for the seismic design of moment resisting timber frames, and to some important detailing rules to be followed to ensure the optimum structural performance. An ARF of 2 was found to be appropriate for one-storey buildings with moment resisting frames