Seismic Upgrades at the Salt Lake Temple
What did the seismic upgrade entail?
The Salt Lake Temple received a state-of-the-art seismic retrofit designed to significantly enhance its earthquake resilience, all while preserving its historic appearance:
- Base Isolation System:
Nearly 100 advanced base isolators were installed beneath the entire foundation. These devices allow the temple to sway safely up to five feet in any direction during an earthquake, effectively absorbing seismic energy and preventing structural damage. - Foundation Reinforcement:
Steel reinforcement was added via a “jack and bore” process—steel tubes filled with concrete inserted beneath existing footings. Additionally, 46 deep holes (~150 feet each) were drilled through the granite walls (vertical coring). These housed post-tensioning cables that anchored the spires to the reinforced foundation, adding stability. - Structural Supports:
Heavy-duty steel roof trusses were installed to strengthen the connection between the north and south walls and support the spires during seismic events.
Process & Timeline:
- Start Date: The seismic upgrades began around late 2019, concurrent with the overall renovation of the temple.
- Major Seismic Work Completion: The key seismic retrofit components, including the installation of base isolators and foundation reinforcement, were largely completed by 2023.
- Overall Renovation End: The entire project was finalized in mid-2025.
Cost:
The total renovation budget for the Salt Lake Temple, including seismic upgrades, was approximately $125 million. The seismic portion represented a substantial part of this budget, given the complexity and importance of strengthening a historic structure.
Were there any issues during the seismic upgrade?
Throughout the seismic retrofit, challenges common to historic preservation and seismic engineering arose:
- Managing the delicate balance between strengthening the structure and maintaining its historic exterior and interior features.
- Precise installation of base isolators and reinforcement components without damaging the original architecture.
- Unanticipated structural conditions sometimes required adaptive solutions.
Fortunately, no significant delays or major issues were reported, and the project was completed successfully.
Seismic Upgrades to the Joseph Smith Memorial Building
Did the Joseph Smith Memorial Building undergo seismic upgrades?
Yes. As part of the broader renovation efforts, the Joseph Smith Memorial Building received seismic enhancements to improve its resilience:
- The upgrades included structural reinforcement of the building’s foundations and seismic bracing.
- Specific details regarding the number and type of seismic devices installed have not been publicly disclosed.
- The project’s scope focused on bringing the building up to current seismic safety standards, similar in intent but smaller in scale compared to the Salt Lake Temple.
Cost of Seismic Work:
Exact figures for the seismic upgrades at the Joseph Smith Memorial Building have not been publicly released. The overall renovation cost for the building was reported around $55 million, but this figure includes interior modernization, expansion, and other upgrades besides seismic work.
Other Buildings on the Temple Grounds
- Other Structures:
The grounds include several additional buildings, such as the Conference Center, Visitors’ Centers, the Church Office Building, and the new entry pavilions. - Seismic Upgrades:
While the Salt Lake Temple and Joseph Smith Memorial Building received major seismic upgrades, specific upgrades to other buildings like the Conference Center or Visitors’ Centers have not been publicly detailed. These buildings are typically designed with modern standards, and any seismic upgrades would likely be part of ongoing maintenance or minor retrofit projects.
Summary:
- Salt Lake Temple: Major seismic retrofit with nearly 100 base isolators, foundation reinforcement, and structural strengthening; started late 2019, completed mid-2025, costing approximately $125 million. No reported major issues during the work.
- Joseph Smith Memorial Building: Underwent seismic strengthening as part of total renovation (~$55 million total for the project); specific details are limited but included foundation and structural reinforcements.
- Other Buildings: Likely received some updates, but specific seismic work details are not publicly available.
If you need more detailed technical reports or official sources, visiting the Church’s news releases or contacting their facilities management may provide additional insights.