Structural engineers for the Rose Avenue Elementary School project in Oxnard, California, a high seismic zone, chose to switch from special moment frames requiring welded connections to the Simpson Strong-Tie Yield-Link moment connection, which features bolted connections instead of onsite welding. This case study shares the experiences of structural engineers, fabricators and other project partners utilizing this innovative solution for structural steel construction.
Strengthening of shear walls and diaphragm-to-wall connections has started on Little Tokyo Towers (see photo 1) located in downtown Los Angeles, CA. This senior–living residential facility was built in 1975. Structural analysis by Tuan and Robinson Structural Engineers showed that some modest strengthening was required to improve the building’s lateral system performance in the event of an earthquake.
Structural renovation work continues on an historic, 1920s-era theater in Hollywood, California. This major renovation will improve the structural performance of the building and help ensure that theatergoers and building occupants are safe in the event of a major earthquake. We are excited to share a second update on this project that focuses on the use of fiber-reinforced polymer (FRP) for strengthening the theater’s roof diaphragm. Continue Reading
We’re excited to share another fiber-reinforced polymer (FRP) project that required both flexural and shear strengthening (photo below) of reinforced concrete joists to enable the slab floors to carry more live load. The structure is in Southern California, and appears to have been built in the 1950s or 1960s when pan joist construction was common. The EOR for this project, Structural Focus, is an experienced structural engineering firm known for seismic retrofit solutions. The FRP applicator was FD Thomas Structural Specialties, a contractor with decades of FRP installation experience.
It can be a challenge to repair an earthquake-damaged structure.
During the 7.1-magnitude 2018 Anchorage earthquake, Gruening Middle School in Eagle River sustained more damage than any other school in the Anchorage School District. Review of the school showed the existing masonry walls suffered damage and separation from the roof. During the retrofit design, the Reid Middleton structural engineering team (Anchorage) determined the masonry walls weren’t adequately reinforced to meet current code requirements. They were seeking an easy-to-install strengthening solution that wouldn’t add significant weight to the building.
The Simpson Strong-Tie® Composite Strengthening Systems™ was used to restore and strengthen 6 distressed cast-in-place concrete grain silos with a combination of carbon and glass FRP, meeting a tight timeline and budget.
Manzanita Hall is one of three remaining buildings on the University of Nevada, Reno, campus that were constructed prior to 1900. Originally named the Girls’ Cottage, Manzanita Hall was built in 1896 and was used to house 97 women in double and single rooms. Architecturally, it a created a Victorian atmosphere and offered a spacious student lounge, complete with a grand piano and a spectacular view of Manzanita Lake.
Several years ago, the hall was deemed seismically inadequate, and the electrical, plumbing and HVAC systems were likewise found to be seriously outdated and insufficient for modern college life. These structural deficiencies necessitated its closure in 2015.
The Freeborn County Fair in Albert Lea, Minnesota, has a rich history going all the way back to 1859, a year after Minnesota became a state. In addition to its longevity as a county fair facility, the Freeborn County Fair is known for its large and spacious grandstand and the many attractions it has hosted since it opened in 1940 — including motorcycle races, stock car races, auto thrill shows, horse races, wrestling events, mule races and tractor pulls.
The primary benefit of fiber-reinforced polymer (FRP) systems as compared with traditional retrofit methods is that significant flexural, axial or shear strength gains can be realized using an easy-to-apply composite that does not add significant weight or section to the structure. Many times it is the most economical choice given the reduced preparation and labor costs and may be installed without taking the structure out of service. However, it is important to make sure the composite is properly designed following industry standards in order to ensure that it is the right product for the application.
To provide you with a better understanding of the topic, it’s important to dispel some common myths and misconceptions that you might hear about FRP: