TRU COMPLIANCE SEISMIC CERTIFICATION
Special Seismic Certification, also referred to as Seismic Qualification, is a product approval in which nonstructural components (such as mechanical and electrical systems) are evaluated for their ability to withstand earthquakes and meet functional requirements following these events.
The goal of special seismic certification is to ensure that:
- Life-safety systems (fire suppression, egress lighting, etc.) function in ALL buildings regardless of occupancy category
- Essential facilities (hospitals, police and fire stations, emergency shelters, military installations, nuclear facilities, etc.) are able to function and provide critical services following a seismic event
- Hazardous and toxic materials are not released in quantities above limits specified by code
The objectives shown above are part of a performance based engineering approach in which buildings and other structures must not only maintain structural integrity, but also meet specific functional objectives. Conventional buildings designed in accordance with the International Building Code focus on a life safety performance objective in which the building may be severely damaged and unable to continue operating. However, essential facilities and life safety systems in all buildings must be shown to remain operational to meet the objectives of the building code. Seismic certification is a critical part in ensuring operational performance objectives are met.
EXAMPLE COMPONENTS REQUIRING CERTIFICATION
When discussing components that require certification, there are three primary requirements to consider:
- Is the component a life-safety system?
- Is the component required for continued operation of a Risk Category IV building?
- Does the component contain toxic, explosive or otherwise hazardous materials that exceeds thresholds established by the authority having jurisdiction?
Aside from these minimum code requirements, it is also possible that the building owner or design team desires to have an enhanced building performance. In this case, specification of seismic certification requirements may be greater than the minimum requirements presented above.
Recent updates to the International Building Code and ASCE 7 documents requires that life-safety systems in ALL buildings be assigned a component importance factor of, Ip, of 1.5. This means that all life-safety systems, in accordance with the building code, are deemed designated seismic systems and are subject to special seismic certification requirements when located in Seismic Design Category C or greater. Items that fall into this designation can include fire suppression systems (including fire pumps and their controllers) and fire alarm control panels.
Essential Components in Risk Category IV Structures
Within the context of performance based engineering, the International Building Code requires Risk Category IV structures (essential facilities) to maintain continued operation after the design earthquake. Some example facilities that may be assigned a Risk Category IV designation include hospitals, emergency response centers, police and fire stations and other facilities that serve a critical community role in the event of a natural disaster. Additionally, ancillary structures that support a Risk Category IV structure are also designated as Risk Category IV.
To accomplish the operational performance objective, various components must remain functional after an earthquake. The International Building Code requires the design team to review the facility and determine which systems and components are needed to maintain functionality and classify them as designated seismic systems, as appropriate. Example components that may be required to function include power systems, HVAC, controls and other critical equipment.
Components Conveying Toxic, Hazardous or Explosive Materials
ASCE 7 requires that components that convey, support or otherwise contain toxic, highly toxic or explosive substances with quantity of material exceeding a threshold established by the authority having jurisdiction and posing a threat to the public if released be deemed a designated seismic system. Additionally, components that convey, support or otherwise contain hazardous substances and are in a facility with a hazardous occupancy should be assigned the classification as a designated seismic system.
Within the International Building Code, Section 414, there is a detailed designation of minimum code requirements relating to toxic, explosive and hazardous materials.
The preceding sections presented information on minimum code requirements that resulted in the designation of equipment as part of the designated seismic system. Building owners and engineers can also classify equipment as essential or otherwise needing to meet enhanced performance objectives. In these cases, the designation as a component of the designated seismic system may be beyond minimum code requirements. This is common in facilities such as data centers that may fall into a Risk Category III designation, however, the owner desired specific systems, such as emergency power and cooling, to remain functional.