Strength and Efficiency of Eccentrically Loaded Layered Timber Columns

The literature on timber structures provides no information on layered timber columns subjected to eccentric loads. This paper presents the results of an investigation into the strength and efficiency of eccentrically loaded bolted layered timber columns. Seventy‐two layered columns covering a wide range of slenderness ratios and three load eccentricities were tested. All columns were fabricated from three component members having similar cross‐sectional dimensions. The test material was No. 1 grade eastern spruce lumber. Compression modulus of elasticity for the test material was obtained from tests on 216 compression specimens taken from each column component member. Strength comparison of eccentrically loaded layered columns, and the efficiency of these columns, is made with respect to theoretical predictions for similar layered columns that are centrally loaded. Column strength is seen to decrease with an increase in column slenderness parameter and with an increase in loading eccentricity. Column efficiency is seen to increase with slenderness parameter, but to decrease as eccentricity increases.