Load Combination Requirements in ASCE Standard 7-10: New Developments

The fundamental load combination requirements for strength design (or load and resistance factor design) appearing in Section 2.3 of ASCE Standard 7-10 incorporate major revisions, among them the treatment of self-straining actions, fluid and soil loads, load combinations for extraordinary events, and probability-based load requirements for non-specified loads. The last item is based on suggested reliability levels for the new performance-based design procedures in the Section 1.3.1 Commentary. The Commentary to Section 2 of ASCE Standard 7-10 presents the technical basis for these changes. Since the basis of the traditional allowable stress design combinations was purely judgmental, the ASD combinations in Section 2.4 have been brought into alignment with the strength combinations in Section 2.3, which have a rational reliability basis.