Gruening Middle School, located in Eagle River, Alaska, was significantly damaged during a magnitude 7.1 earthquake on November 30, 2018. Gruening was shut down for almost three years. Engineers first evaluated Gruening on Sunday, December 2, 2018, and the building was red-tagged per ATC-20-1 Field Manual – Post-earthquake Safety Evaluation of Buildings.
Design began on the Gruening Middle School Earthquake Recovery Project in the spring of 2019. Engineers referenced ASCE 41 and ASCE 7 for structural design. The building was to have its heavy masonry veneer removed for architectural reasons and reduced seismic weight. Engineers then reviewed the existing interior CMU walls compared to the current design and detailing standards. Although the ASCE 41 Tier 1 screening compares CMU wall reinforcing to a maximum spacing of 48 inches on-center, the current MSJC code requires a minimum spacing of 24-inch spacing for both vertical and horizontal reinforcement. The spacing of the existing masonry reinforcing at Gruening was 32 inches vertical and 48 inches horizontal; the existing CMU walls at Gruening did not meet the minimum spacing requirements of the current MSJC.
A clever solution was needed to provide additional reinforcement while minimizing weight and meeting the project budget. FRCM provided a novel solution to accomplish the objectives: upgrading existing stack bond CMU walls to meet current MSJC requirements and strengthening tall walls to meet out-of-plane capacity requirements. FRCM closed the reinforcement gap, reduced schedule impacts, and provided increased performance economically for the project. With close collaboration between the contractor, Simpson, and the engineer, the FRCM installers could place the FRCM ahead of schedule. The installers covered approximately 36,000 square feet of wall with FRCM per the structural drawings and increased the resiliency of the existing structure for future events.
ABOUT THE SPEAKERS
Alex Daddow is a registered professional engineer in California, Colorado, Idaho, Montana, Nevada, Utah, Alaska, Washington, Oregon and Wyoming. He graduated from Cal Poly San Luis Obispo with a degree in Architectural Engineering. Before joining Simpson Strong-Tie in 2019, Alex was a consulting engineer working on podium structures, custom housing, bridges, historic retrofits, schools and advanced foundation systems. He is now a Senior Composite Strengthening Systems (CSS) Field Engineer and educates the industry on composite systems throughout the Southwest region. Alex also works directly with specifiers, installers, contractors and plan reviewers, assisting them with the technical aspects of designing and building Composite Strengthening Systems.
Ellen Hamel, PE, SE, has over 15 years’ experience in the structural design of a variety of structures, including government and academic buildings, docks, oil and gas facilities, and pedestrian and vehicular bridges. She is fluent in a range of design codes and engineering software. In addition to structural design, she has a strong background in construction administration and field coordination. Ellen obtained a Bachelor of Science in Civil Engineering from Tufts University and a Master of Science in Structural Engineering from the University of Colorado. She has lived in Alaska since 2011.