Reliability of Wood Structural Systems

Abstract

A methodology for the study of reliability in wood structural systems under load is presented. The approach implements duration of load effects by means of a damage accumulation model, and combines it with a structural analysis of the system. The reliability under a random, varying load is then calculated at the end of the intended service life for the structure. Both strength and serviceability limit states are considered. As an example, the eliability of a flat roof under snow loads is studied. Weather data from two Canadian cities (Vancouver and Quebec) are used, and allowable roof spans are derived to satisfy a target reliability at the end of 30 yr. Load sharing and load duration adjustment factors are derived in relation to a design equation in Limit States Design format, with the condition that a prescribed reliability be associated with the resulting span.