| Title |
Study on the Estimation of Resistance Factors for Korean Larch Lumber to Convert Timber Design Standards to Load and Resistance Factor Design |
| Authors |
백승엽(Baek, Seung-Youp) ; 오근영(Oh, KeunYeong) ; 박금성(Park, Keum-Sung) ; 김예인(Kim, Yein) ; 방성준(Pang Sung-Jun) ; 신동현(Shin, Dong-Hyeon) |
| DOI |
https://doi.org/10.5659/JAIK.2026.42.9.355 |
| Keywords |
Load and Resistance Factor Design (LRFD); Reliability Index; Resistance Factor; Lumber; Monte Carlo Simulation |
| Abstract |
This study estimated resistance factors for Korean larch lumber to support the transition of domestic timber design standards from allowable
stress design (ASD) to load and resistance factor design (LRFD). Previous studies on resistance factor calibration methods were reviewed to
identify key variables required for reliability-based evaluation, including strength distribution, load ratio, target reliability index, and reliability
analysis method. Based on this review, target reliability indices of 2.5?3.0 and dead-to-live load ratios of 0.25?4.0 were adopted in this study.
Strength data for bending, compression, and shear members were modeled using two-parameter Weibull distributions, and Monte Carlo
simulations were performed. The reliability index was evaluated using allowable stress, code-converted stress, and test-derived 5th percentile
strength. The proposed resistance factors were 0.75 for visual grade No. 1, No. 2 bending members, 0.70 for visual grades No. 3 bending
members, 0.75?0.90 for compression members depending on the target reliability level, and 0.90 for shear members considering the
uncertainty of small-clear-specimen shear data. The results show that resistance factor calibration for domestic timber should consider member
type, strength distribution, load ratio, target reliability level, and test method. |