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Salt Lake Temple renovation makes strong progress with foundation work, pedestrian tunnel, structural upgrades

SALT LAKE CITY — Amid the roaring backdrop of a bustling jobsite, a quiet resolve about the project’s ultimate aim still rings clearly in every worker’s ear at the Salt Lake Temple.

Project Engineer Nathan Espinoza says the ever-present reminder for each work team jobsite-wide is that the Salt Lake Temple renovation is a project that matters to millions of worshippers and holds deep symbolic significance for a worldwide faith. This persistent mindset about the importance of the work has added an extra measure of urgency, collaboration and precision to every task, according to Espinoza.

“It’s amazing how much care and attention to detail is continually put into the work,” he said. “We know that what we’re doing touches people on multiple levels. It just makes it that much more rewarding when we’re able to solve unique challenges that come up during the project.”

Like with any major historical renovation, Jacobsen Construction’s work on the temple has yielded some surprises and has required a nimble and adaptable approach to the work being done. One big example of this was the temple foundation being wider from east to west than was expected based on historical documentation.

“None of the historical drawings really showed how wide it was. So everything was engineered off what we thought we know, and then when we dug it up, we had to figure out how to make it work without a full re-design. So project leaders worked with the engineers and decided to rope-saw the foundation so it fits what’s shown in the drawings,” said Project Engineer Tanner Patterson.

In order to have room to narrow the foundation as needed via rope saw, some steps at the bottom of entranceways on the east and west sides had to be removed.

Numerous jobsite tasks are underway to ensure that the foundation of the Salt Lake Temple is as reliable and resilient as possible. The temple’s enormous weight is first being shifted to a temporary foundation before being moved onto sophisticated base isolators designed for rigorous seismic protection. One eye-catching way that the footprint of the temporary foundation is being strengthened is by digging multiple 3-foot by 5-foot holes at each corner of the temple that all go more than 20 feet deep, and then re-filling these holes with stronger material and reinforcing them with rebar and rock anchors. (The holes are shored on the way down so as not to collapse on themselves.) Ultimately, the temporary foundation is much less prone to encountering problems during any disturbances to the ground during heavy construction onsite, and is also designed to more readily transfer to the permanent base isolator system once that system is ready, Patterson said.

“We’ll be able to encapsulate the temple, pick it up and then put all the weight on the permanent system,” he said.

Enormous and massively heavy secant walls wrapped around the perimeter of the foundation will also be part of the permanent system; secant wall work is set to resume upon the foundation footprint being trimmed to its expected size.

Other progress on the exterior of the temple include the expansion of scaffolding around the outside of the building, giving easier access for the transport of material in and out of the building at higher levels. This has also expedited the removal and cleaning of massive exterior temple stones, which will eventually be placed again on the structure. Fencing has also been erected on the Church Office building, where the grounds are in the beginning stages of being renovated.

Intensive interior work underway

There are also wide-ranging efforts underway to strengthen the temple structurally in the interior. These efforts, once complete, are a big step in allowing several other aspects of the project to move forward. One critically important task was the installation of several beams to bear the weight of Level 5 of the building, replacing an interior brick wall that was removed. This was done with several hydraulic jacks that each use a different PSI to hold up specific portions of Level 5. The beams, which run across the entirety of Level 5, will eventually be replaced in a delicate process by a single substantial post-tensioned beam that will serve as the permanent load-bearing component, Espinoza said.

Several smaller tasks are also currently happening inside the temple: Project teams uncover and examine each archway throughout the interior, as decisions are made on a case by case basis about whether to demolition each arch or structurally strengthen it; workers strategize about how to best preserve pioneer craftsmanship on the walls and ceilings through climate control and other protective measures; and mechanical, electrical and plumbing systems are installed.

From the smallest details to the biggest challenges, Espinoza said, every person working on the Salt Lake Temple renovation is led and inspired by a sense of the hallowed history of the building and the Mormon Pioneers’ devotion to building it up.

“Church history has helped us understand that all that the finished temple was literally was the result of blood, sweat and tears by those who were here before us,” he said. “We know that our efforts are something that needs to happen, and that we are building up the legacy of the original builders by renewing the lifespan of the temple.”

Pedestrian tunnel begins to take shape

A huge pedestrian tunnel is being constructed under North Temple and will serve as a primary entrance onto the temple grounds for worshippers and visitors who use the parking accommodations across the street at the Conference Center of The Church of Jesus Christ of Latter-day Saints.

When complete, this 125-foot tunnel will greatly improve easy walking access to the Salt Lake Temple and expand the number of viable parking options for those visiting the sacred structure.

Over the winter, 27 massive canopy tubes, each spanning the entire length of the soon-to-be tunnel, were drilled in at the top of it to provide structural stability. These tubes needed to be in place before the launch of excavation and mining efforts, which started in early Spring.

The mining at the tunnel site was in its early stages by mid-March, with workers having made mined through a few feet already. The work of clearing space for the tunnel is very intricate and requires lots of detailed precautions and careful sequencing along the way in order to ensure the ground throughout the entire affected area stays stable and safe, said Project Engineer said Michael Tinney, the geotechnical engineer for Kilduff Underground Engineering who designed the tunnel and is working onsite to ensure it is built as intended. The process being used to accomplish that is a proven strategy called the sequential excavation method, Tinney said.

“This means we’re taking a little bite out of the top and then re-supporting it, followed by taking a bite out of the bench at the bottom and then re-supporting that,” he said. “You don’t want to take out too much at once, because the ground conditions show us that there’s not much keeping the ground held together so it tends to present problems if you get a little bit ahead of yourself. So it’s in your interest so go sequentially, slowly, smoothly — just doing your excavation and your follow-up support all the way through.”

Tinney added that there is “not too much ground cover between the top of this tunnel and the North Temple roadway right above,” making it all the more important to have every small detail planned out to ensure total stability throughout the process.

Sensors throughout the area would immediately detect any problematic ground settling or any other unwanted or unexpected movement, no matter how slight, Jacobsen Construction Project Manager Richard DeLaMare said.

“We’re watching that constantly. We haven’t had any issues at all, but we do have our pulse on that,” said DeLaMare, who is overseeing all work on the tunnel.

For more than a year, DeLaMare said, there has been extensive engineering and planning to ensure the tunnel could be delivered according to the Church’s plans, and done so in a way that all parties, including multiple engineers and Salt Lake City officials, were completely confident was safe. The construction of the tunnel is considered more complex than nearly other part of the Salt Lake Temple renovation, second only to the seismic upgrade on the temple structure itself, he added.

“We’ve been planning the details of this for quite a while now. We’re very proud of the efforts and collaborations we’ve had with the Church and the city,” DeLaMare said.

The tunnel will be a beautiful and functional addition to the temple grounds, Tinney said, and he’s eagerly anticipating seeing the finished product firsthand.

“It will be a great sense of pride to see this thing leap off the page and become a real structure.”

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