CREDIT: Photo courtesy of USGC
September is National Preparedness Month, the perfect time to see how safety precautions integrated within building construction can protect tenants and material value from emergency situations. This article explores retrofits that can protect against earthquakes.
Earthquakes can wreak havoc on buildings, making large seismic joints critical for today’s code standards. Use a closing system that automatically reseals itself after a seismic event or a flexible cover, which can prevent wall and ceiling finishes from damage. Gravity activated seismic floor covers also return to a normal position after an event. These retrofit solutions minimize facility damage, offer occupants safe egress, and provide structural resilience against seismic activity.
Safeguard Your Building
Every retrofit project has unique movement criteria, making it important to understand how to integrate movement into expansion joint sizing and coverage. Sizing the building’s expansion joint appropriately to accommodate the joint cover assemblies and any accessories (such as fire, insulation, or vapor barriers) is necessary to ensure top performance during and after an event. This includes day-to-day movement cycles as well.
The California Memorial Stadium at the University of Berkeley, for example, faced a significant reconstruction challenge – the owners wanted to preserve the historic facade while adding seismic reinforcement. In addition to being built over the Hayward Fault, the precast horizontal stairs and vertical seating added a layer of complexity.
The solution was a series of angled joint covers that cut across the seating bowl and followed the profile of the stadium seating. Each custom joint accommodates 12 inches of expansion, compression, and lateral movement while preventing holes or gaps.
Design for Resilience
Off-the-shelf solutions rarely work for retrofits, making this a field of customization. To effectively communicate specifications needed to the manufacturer, facility managers should understand their loading needs. Manufacturers may then select a cover type that can be engineered appropriately for the required loading scenarios and expansion joint cover connections that will effectively transfer loads back to the structure.
When the Utah State Capitol underwent its seismic retrofit, the 98-year-old, 320,000-square-foot building needed to accommodate 24 inches of universal movement. Project managers closely examined the loading conditions of each moat cover area and the connections back to the structure. Covers were designed so they could adequately carry pedestrian traffic and maintenance equipment and ensure that the moat cover finishes would endure maximum loading conditions.
Consider Aesthetic Appeal
What joint finishes will compliment your space? Working with your manufacturer closely will ensure an effective solution that naturally blends with the existing structure. Consider how daily building movement may displace cover systems. To avoid an undesired finish or hazard, select a qualified installer to ensure a quality installation with the desired finish.
After withstanding a 1989 earthquake, the de Young Museum in San Francisco needed a covert way to prevent further damage. During a 1993 rebuild, the facility incorporated a base isolation system that could flex up to 42 inches in any horizontal direction. Though placed on the building’s exterior, the seismic joints are hidden underneath a copper skin.
Expansion joint covers that bridge the gaps created by seismic retrofits are critical elements that positively affect structure stability, occupant safety, and building aesthetics. Providing new buildings and existing structures with enhanced measures greatly increases resiliency and long-term property value. Bestowing your property with the capability to withstand a seismic event is a critical step that’s never too late to consider.
Kevin W. Smith, PE, is the Engineering Manager for the Expansion Joint Cover Division at Construction Specialties. Kevin can be reached at KSmith@c-sgroup.com.
Currently rated by 0 people