RELIABILITY ANALYSIS ON COMPRESSION STRENGTH PROPERTY OF CHINESE LARCH VISUALLY-GRADED DIMENSION LUMBER

摘要

The reliability analysis method was investigated in this study to obtain design values of ultimate compression strength parallel to grain (UCS) of Chinese larch visually-graded dimension lumber of common size. A total of 748 lumber samples of 40 by 90 mm were tested for static full-size compression strength according to Chinese National Standards' requirements of the reliability index. The goodness of fit for the UCS distribution of four visual grades was analyzed and the first-order second-moment reliability analysis under different load cases was performed based on all the test data. The log-normal distribution was the optimizing fitted distribution of the compression strength of Chinese larch dimension lumber. Design values of the compression strength for grades I-c, IIc, IIIc and IVc were suggested for the minimum reliability index. These design values will be recommended to the standard committee of Chinese National Standards.