2012 IBC Section 1604.10 requires the lateral force-resisting system of a structure to comply with the seismic detailing requirements and limitations of the 2012 IBC and ASCE 7-10, irrespective of how great the wind effects might be in comparison with the earthquake effects.

It is important that engineers realize how wind and seismic forces are different. Yes, they are both dynamic. Yes, the code specifies both in terms of equivalent static forces. But the way they are induced in a structure is quite different. Whereas wind loads are external loads applied and, therefore, proportional to the exposed surface of a structure, earthquake forces are essentially inertia forces. The latter result from the distortion produced by both the earthquake motion and inertial resistance of the structure as explained in our blog: What are Earthquake Forces and How Does A Structure Respond?

Seismic design is done using code-prescribed forces, which are reduced below the level that would have produced elastic structural response to the design earthquake of the IBC, as explained in our blog: Why Don’t We Design a Structure to Respond Elastically to Design Earthquake Ground Motion?

The IBC and ASCE 7 require that the detailing requirements of the materials chapters be complied with, irrespective of how high the wind effects might be in comparison with the earthquake effects. Wind and earthquake effects are not considered to occur simultaneously on a structure in U.S. design practice. Section 1605 contains gravity load combinations, combinations of gravity and wind loads, as well as combinations of gravity loads and earthquake forces. Design of every critical section of every structural member must be done considering all of these load combinations. If the gravity and wind load combinations produce demands that are closer to the design strength of a section than do the combinations of gravity loads and earthquake effects, then wind rather than earthquakes may be thought of as governing the design of that section. If the same happens for every critical section of a structure, then wind may be thought of as governing the design of that entire structure. However, this fact has no bearing on the necessity to comply with the detailing requirements of the materials chapters. This is because the design wind forces are required to be resisted elastically by a structure. There are no corresponding inelastic deformations to worry about. The design earthquake forces, on the other hand, are based on the premise that the structure will undergo inelastic deformations in the design earthquake and that the structure will be detailed to have inelastic deformability equaling or exceeding the inelastic deformations.

Theoretically, it could be argued that if wind effects were larger than unreduced earthquake effects (earthquake effects corresponding to the elastic response of the structure to the design earthquake of the IBC), then the detailing requirements of the code could be dispensed with. However, even that is not allowed by the IBC for building structures.

Totally irrespective of the severity of wind effects, the seismic design categories defined in Section 1613.5.6 would determine the applicability of the detailing requirements. The seismic design categories are used in the IBC and ASCE 7 to also determine permissible structural systems, limitations on height and irregularity, those components of the structure that must be designed for seismic resistance, and the type of lateral force analysis that must be performed.