Title:
Repair and Retrofit of Earthquake Damaged Middle School with FRCM: A Case Study
Author(s):
Alex Daddow
Publication:
Web Session
Volume:
ws_S24_AlexDaddow.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
3/24/2024
Abstract:
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 – Postearthquake Safety Evaluation of Buildings (ATC-20). Design began on the Gruening Middle School Earthquake Recovery Project in spring 2019. Engineers referenced ASCE 41 and ASCE 7 for structural design. As part of this project, engineers reviewed the existing CMU walls compared to current design and detailing standards. In collaboration with Simpson engineers, Reid Middleton and ASD elected to use FRCM on all existing CMU walls in the building. The use of FRCM accomplished two objectives: upgrading existing stack bond CMU walls to meet current MSJC requirements and strengthening tall walls to meet out-of-plane capacity requirements. FRCM combines a high-performance mortar with a carbon-fiber grid to create a thin structural layer that does not add significant weight to the project. Reid Middleton and the Simpson team worked closely during the design and construction phases to ensure a smooth installation. 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.