Development of Performance-Based Seismic Design Guidelines (PBSDG)

The Federal Emergency Management Agency (FEMA) is committed to reducing the ever-increasing cost that disasters inflict on our country. Preventing losses before they happen by building to withstand anticipated forces, is one of the key components of mitigation. Mitigation is the only truly effective way of reducing the cost of these disasters. One of the more promising methodologies that can be used to reduce damages from an earthquake or other similar hazard over and above the current life safety target of the nation's current building codes is performance-based design. Current building codes for the design of new buildings are prescriptive in nature and are intended principally to provide for a life-safety level of protection when the design-level event such as an earthquake occurs. While these codes are intended to produce buildings that meet a life-safety performance level for a specified level of ground shaking, they do not provide a procedure that enables the designer to determine if other performance levels will be achieved or exceeded. During a design level earthquake, a code-designed building could achieve the goal of preventing the loss of life or life-threatening injury to the occupants, but could still sustain extensive structural and nonstructural damage and be out of service for an extended period of time. In some cases, the damage may be too costly to repair, with demolition being the only option. While some current design guidance and building codes for existing buildings do incorporate some performance based design elements, these are older criteria that do not address issues explained below.