IAA summary of parking garage canopy tear
INDIANAPOLIS – At approximately 9 a.m., a portion of one of nine sections of canopy fabric covering the Terminal Garage failed for an undetermined reason, dispersing some snow on the top floor and interior of the garage. The canopy consists of three large pieces of fabric joined and attached to ten steel trusses to form a nine-section covering.
There were no injuries and no damage to vehicles or building structures. However, one component of the art installation Breath was damaged. Snow has been removed from the affected area, and the garage remains open and operating normally.
On February 5, 2011, a collapse involving three of the nine sections of canopy fabric occurred. The collapse happened shortly after a significant ice storm and a snow storm during which six inches of wet, heavy snow fell at the airport.
Following the 2011 canopy collapse, the Indianapolis Airport Authority (IAA) selected Span Systems, Inc., to replace the damaged sections and improve the comprehensive design relative to the fabric and its supporting framework in order to ensure that a collapse would not happen again. The modifications included attaching the fabric to each of the trusses (instead of every third truss) and tightening the fabric. This was intended to distribute the weight of accumulated snow and ice more evenly and also avoid creating tension around key areas; it is believed that these modifications helped contain today’s partial collapse to only one section, limiting the failure to the area near the fabric’s attachment point to the truss.
The steel structure was also inspected after the 2011 collapse but was not damaged, and no modifications were made other than changing how the fabric attached to the steel.
Span Systems, Inc., of Manchester, New Hampshire, a specialist in tension membrane structures, designed and installed the replacement and repair, and a review of the design was conducted by Gieger Engineers of Suffern, New York. In addition, the IAA’s property insurance carrier, AIG, conducted its own, independent assessment. All three engineering analyses concluded that the fix was an appropriate measure to prevent future failures or collapses related to the weight of snow and ice.
Span Systems assured the IAA that the biggest risk factor for the canopy structure was high winds and that the design of the structure would naturally dissipate snow and ice as it accumulated, mitigating the risk of failure or collapse. Regardless, the IAA, as an organization that prides itself on safety, performs regular inspections of the canopy, including after high-wind events and snow events.
The canopy is under warranty, and Span completed an 18-month inspection in July 2013. IAA is in communication with Span Systems to pursue immediate corrective actions.
The canopy was original constructed by Bird-Air as part of the midfield development. The manufacturer of the fabric is St. Gobain Performance Plastics Corporation, a-Paris-based multinational corporation of high-performance polymer products.