Document: NUREG-0800
Document ID: 072325a8-02ea-4d59-bb3f-06592c340804
Document Type: srp
Title: The Aluminum Association, Specification for Aluminum Structures
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070327.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.4
CFR Part: 
CFR Title: 

Content:
rs regarding consideration of additional load effects in designing steel structures. The notes are parts of SRP Sections 3.8.3 and 3.8.4. (3) The research done in the last 12 years on the strength and stability of compression members shows that the base curve (SSRC curve in Figure F.1) used in arriving at the SLCs in SRP Sections 3.8.3, and 3.8.4, and in the standard does not reflect the results of the available test data. In developing the American Institute of Steel Construction (AISC) building specification based on the load and resistance factor design (LRFD) concept, the AISC changed the formulation for compression members to reflect the results of the test data. The LRFD curve (with =1.0) is also shown in Figure F.1. DRAFT Rev. 2 - April 1996 3.8.4-48 Based on the test data, this curve has the minimum reliability index, (defined as the ratio of ln (R /Q ) to (V + V ) ; where R = median value of resistance, Q = median m m r Q m m 2 2 1/2 value of load; and, V , and V are the corresponding coefficients of variation), of 2.6 r q (LRFD Specification for Structural Steel Buildings and Its Commentary, Published by AISC, Chicago, September 1, 1986). The LRFD specification requires = 0.85 in establishing the resistance of compression members. Figure F.1 of this Appendix shows the curves reflecting the SLCs of 1.0, 1.4, 1.5, 1.6, and 1.7 as applied to the stresses specified for allowable stress design of the AISC. Based on the comparison with the LRFD curve ( =1.0), the following SLCs are recommended in the interim position: SLC of 1.6 ( 0.95) for load combinations 10 and 11. This is reasonable for load combinations containing the effects of the two low-probability events, that is, safe- shutdown earthquake (SSE) and loss-of-coolant accident (LOCA). SLC of 1.4 ( 0.84) for load combinations 7, 8, and 9. This is appropriate for combinations containing the effects of a single, low-probability event, that is, SSE, tornado, or LOCA. SLC of 1.3 in load combinations 2, 5, and