Analysis of depth factor in Pinus sylvestris L. structural timber

E. Hermoso, J. I. Fernández-Golfín, M. R. Díez


An adjustement depth factor for bending strength (MOR) to the standarized size of 150 " 50 mm of different Spanish provenances of Pinus sylvestris is assessed. For obtaining such a factor different models are adjusted, by non-linear regression, between MOR and depth and/or width. In order to study the influence of grade such a models were obtained not only for the total population but for the two different grades (ME1 and ME2) considered in the Spanish UNE 56.544 visual grading standard. The influence of the depth (h) and the volume into the bending strength (MOR) of timber is significative, especially in the lower grades (ME2). The average depth factor (kh) is similar than the one considered in EN 384, even though the influence of visual quality is evident, being higher in the lower grade (ME2) than in the high grade (ME1) one. The influence of the width has not statistical significance and can be neglected. A final comparison with the results of another study on Pinus nigra is also carried out, concluding that the conclusions on a given species can´t be extrapolated to others.


Pinus sylvestris, L.; depth factor; bending Strength