Structural failure in large-span timber structures: A comprehensive analysis of 230 cases

Abstract

This paper presents a comprehensive statistical analysis of structural failure in 230 large-span timber structures. The objective is to identify typical failures and their causes to enable structural engineers in charge of comparable structures to initiate necessary measures to avoid similar failures. The analysis shows the wide range of use of large-span timber structures such as buildings of public assembly, sports halls and storage facilities. More than two thirds of the structures were realized with glued-laminated timber. The most frequently observed failure is cracking along the grain (46%). The causes for such failure are low or frequently changing wood moisture content as well as systematic tensile stresses perpendicular to the grain resulting from the geometry of the structural elements. Almost half of the timber components featured low moisture contents of 10% or less. The majority of failures can be linked to planning errors. Timber products, manufactured and installed according to the state-of-the-art, are rarely the cause for failure. The same applies to high snow loads, which could partly be identified as the triggering event but not the cause for failure. Proposals to decrease errors and thereby the occurrence of failures are given.