5.2 Design Considerations
The selection of design solutions must be consistent with the scope and objectives selected for the project. For all items covered by the code provisions, design solutions must meet or exceed the applicable building codes and standards, such as ASCE/SEI 7-10. For the engineering consultants engaged to provide design solutions, the selection of seismic force levels, design coefficients, and design methods depends upon the Seismic Design Category. The design team and owner need to be clear about the performance objectives and the level of seismic protection that will be targeted. There may be items not explicitly covered by the code where some design solutions can be implemented by the owner or the initial tenants without consideration of the building code and without engineering expertise.
Specific design solutions for nonstructural items fall into three broad categories. These were described in Chapter 4 and are repeated here because the application is somewhat different for new construction
- NON-ENGINEERED (NE): These are typically simple, generic details or common sense measures that can be implemented by a skilled laborer or by maintenance personnel using standard items from a hardware store. Although these solutions are not appropriate for essential facilities, they may be useful for the restraint of items not directly covered by code provisions such as furniture and contents that lie below the code threshold but may still fall and injure occupants. Some of these solutions might be implemented by the owner and the original design team; others by the initial tenants.
- PRESCRIPTIVE (PR): Prescriptive details are available in the public domain and have been engineered to meet or exceed code requirements for a set of common conditions and can be used directly in many situations. While there are only a limited number of these details currently available, we anticipate that more such details will be developed as engineers, architects, and specialty contractors become more familiar with the new ASCE/SEI 7-10 requirements for nonstructural components. Some of the prescriptive details have been developed for hospitals, schools and residences in California, and have been successfully implemented for many years. Examples are provided in Chapter 6.
- ENGINEERING REQUIRED (ER): These are nonstructural anchorage details specifically developed by a design professional on a case-by-case basis for a specific set of conditions. Design methods and design coefficients are selected based on the Importance Factor and Seismic Design Category, per IBC 2012 and ASCE/SEI 7-10, as discussed in Section 5.3.1. Higher design forces and more complex engineering methods may be required to meet performance objectives higher than those embodied in the building code provisions.