12.7.1 Foundation Modeling: To determine seismic loads, it is permitted to consider the structure to be fixed at the base.

12.7.2 Effective Seismic Weight: The effective seismic weight, W, of a structure includes the dead load, as defined in Section 3.1.

12.7.3 Structural Modeling: A mathematical model of the structure is generated for the purpose of determining member forces and structure displacements resulting from applied loads and imposed displacements.

Structures are analyzed using a 3D representation. 3D modelling should consist a minimum of three degrees of freedom consisting of translation in two orthogonal plan directions and rotation about the vertical axis.