A DEVELOPMENT OF MATERIAL SAFETY COEFFICIENTS FOR SOLID TIMBER IN NIGERIA BASED ON EUROCODE

Abstract

The Nigerian code of practice for the design of timber structures NCP2 [1] based on the permissible stress design method with reference to British standards CP112 [2], which had passed through several revisions since 1967, up to B5268 [3], now replaced with the Eurocode 5 [4]. There is therefore the need to revise the Nigerian Timber design standard based on the current International trend. Currently, many developing countries like South Africa, Malaysia and Singapore are adopting and domesticating the Eurocode. In order for Nigeria not to be left out of the current global trend for its quest to be among the first twenty great economies by the year 2020, development of local limit state design code for timber structures in Nigeria through the adoption of the Eurocode 5 was proposed in this paper. Local material safety coefficients based on the extensive data on the material properties of Nigerian solid timber made available by the research unit of Cirad [5] were calibrated. The calibration was undertaken based on reliability principles in order to fully accommodate uncertainties that are inherent in the properties of timber. Code calibration software developed by the Joint Committee on Structural Safety (JCSS) was adopted.