6.3. Structural design

After the proper site is selected, the next important step is to develop an infrastructure design that provides a level of safety consistent with the protection goal set for the facility. The protection systems being considered should be realistic and lend themselves to effective maintenance.

Based on the architectural concepts, a preliminary proposal is prepared that defines how services and spaces will be organized, and what form the facility and its operations will take. Given the hazards to which the building is exposed, it will be necessary at this stage to choose an effective layout for the building and its systems. For example, in flood prone areas, the building’s finished floor level should be above flood level. In areas of strong winds, the geometry of the ceiling and the sheathing are very important. In areas where it is necessary to protect against seismic forces, specific design standards should be adhered to.

The components of the facility’s structural system should be designed to resist the normal ongoing and possible occasional stresses that can affect a structure, including its own weight, usage overloads, earthquake, wind gusts, snow or ash load, extreme temperatures, pushing forces from land or water, total or differential settling of the foundation, etc. It is very important to plan systems that can be quickly reestablished if damaged or operations are interrupted (an additional reason for this concern is the importance of avoiding creating panic by evacuating a facility if that is avoidable).

In seismic areas, it is important to use earthquake-resistant design standards (as examples, see CUBIC, the Caribbean Uniform Building Code and California, USA’s Hospital Seismic Safety Law). The selection of the professionals to be involved in preparation of the design is also important. In addition to structural engineers, other experts should have proven knowledge and experience with this type of building.

Finally, as part of the system’s quality improvement strategy, it is important to emphasize the role of the review group in ensuring that the proposed level of protection is achieved as the project moves forward.