Salt Lake Temple has begun ‘jack and bore’ process to strengthen its foundation. Here’s what that looks like

In the past month, the Salt Lake Temple has begun a major seismic strengthening process called “jack and bore” as steel pipes are inserted below its existing foundation. 

The September 2021 renovation update on the Church’s Newsroom explained this process and provided additional information about excavation and truss installation. The Salt Lake Temple renovation project began at the end of December 2019 and is expected to take four years. 

Aerial view of Temple Square during its renovation, Salt Lake City, September 2021.
Aerial view of Temple Square during its renovation, Salt Lake City, September 2021. Credit: The Church of Jesus Christ of Latter-day Saints

‘Jack and bore’

The first steel pipe was inserted in late August under the east towers. A total of 92 pipes — 40 feet long and 3.5 to 4 feet in diameter — will support the temple’s foundation. 

Crews insert a steel pipe below the existing foundation of the Salt Lake Temple as part of a seismic strengthening process called "jack and bore," September 2021.
Crews insert a steel pipe below the existing foundation of the Salt Lake Temple as part of a seismic strengthening process called “jack and bore,” September 2021. Credit: The Church of Jesus Christ of Latter-day Saints

The soil is removed, initially by hand, from inside the pipe as it is gradually inserted horizontally, according to the news release. The gap between the outside surface of the pipe and the surrounding soil is then filled with grout. Once installed the pipes will be filled with reinforced steel, including post-tensioning strands and high-strength concrete. 

Construction workers fill the new pipes in the Salt Lake Temple foundation with reinforced steel, September 2021.
Construction workers fill the new pipes in the Salt Lake Temple foundation with reinforced steel, September 2021. Credit: The Church of Jesus Christ of Latter-day Saints

Excavation

Excavation has continued on the north side of the temple past the level of the entrance tunnel, providing space for three new underground floors, which will be used as an addition to the temple. 

Crews excavate past the level of the entrance tunnel on the north side of the Salt Lake Temple, September 2021.
Crews excavate past the level of the entrance tunnel on the north side of the Salt Lake Temple, September 2021. Credit: The Church of Jesus Christ of Latter-day Saints

The tunnel will connect the Salt Lake Temple to the underground parking garage in the Conference Center to provide safer and easier access to those visiting the sacred edifice.

Additional excavation creates room for three new levels of the Salt Lake Temple, September 2021.
Additional excavation creates room for three new levels of the Salt Lake Temple, September 2021. Credit: The Church of Jesus Christ of Latter-day Saints

Trusses

Two new trusses were installed on the roof of the temple, and three of the eight areas, or bays, have been completed as part of the truss installation. To protect the interior finishes of the building, the roof is closed each time new trusses are installed.

Installation of two new trusses on the Salt Lake Temple roof is completed, September 2021.
Installation of two new trusses on the Salt Lake Temple roof is completed, September 2021. Credit: The Church of Jesus Christ of Latter-day Saints

Secant wall

The secant wall that acts as a retaining wall around the temple continues to be excavated to prepare for the three future floors underground in a temple annex and to contain the soil under the temple.

The secant wall surrounding the Salt Lake Temple is uncovered to prepare for the three future floors underground, September 2021.
The secant wall surrounding the Salt Lake Temple is uncovered to prepare for the three future floors underground, September 2021. Credit: The Church of Jesus Christ of Latter-day Saints
Members of the renovation team dig to prepare the secant wall for new underground levels that will be added to the Salt Lake Temple, September 2021.
Members of the renovation team dig to prepare the secant wall for new underground levels that will be added to the Salt Lake Temple, September 2021. Credit: The Church of Jesus Christ of Latter-day Saints
Scaffolding and cranes seen from the north side of the Salt Lake Temple during its lengthy renovation project, September 2021.
Scaffolding and cranes seen from the north side of the Salt Lake Temple during its lengthy renovation project, September 2021. Credit: The Church of Jesus Christ of Latter-day Saints

Read more about the Salt Lake Temple renovation at TempleSquare.org.