Utah’s Voice of the A/E/C Industry

The continued spread of and improvements to BIM, new fuse plate technology, and the rise of mass timber are a few of the topics shaking up structural engineering in the Beehive State. Utah Construction + Design reached out to some Utah’s leading structural engineering firms to find out about current trends, technologies, and with five years of reflection, how are owners and designers looking at and learning from the 5.7 magnitude earthquake that shook the Wasatch Front in spring 2020. Jerod Johnson, Senior Principal at Reaveley Engineers, wrote a detailed retrospective of the event in 2023 and says researchers and engineers learned a few things from the quake from how different building types responded to insights into the geology of our region. “Research has revealed that the shape of the Wasatch Fault is different from what was previously believed. The Magna earthquake, initially thought to have occurred on a fault in the western part of the Salt Lake Valley, actually took place on the Wasatch Fault. The fault extends into the valley at a much shallower angle than expected, rather than descending steeply from the toe of the mountain. This new understanding of the fault's geometry has significant implications for seismic design and building codes. We anticipate changes to the spectral acceleration maps used in structural design. The lateral shaking observed during the 5.7 magnitude earthquake was much higher than expected,” says Johnson. “It highlighted the need for updated design practices that account for this amplification. These findings will influence future building codes and practices in Utah, ensuring that structures are better equipped to withstand such events.” But Chris Hofheins, a Senior Principal at BHB Structural, is concerned the wider public may not have learned enough from the event. “Most structural engineers thought the earthquake would be a wakeup call but to a large degree I think it had the opposite effect,” said Hofheins. “People looked around and felt like it wasn’t so bad and we’ll be alright if something bigger hits. We’ve seen a few owners who decided to increase the seismic safety of their buildings but we’re also seeing the opposite where I think some people are overconfident.” Blowing a Fuse Structural resilience, designing buildings that not only protect those inside during a seismic event but can be quickly reoccupied, continues to be of great interest to structural engineers. Replaceable fuses, or structural sections that can be sacrificed dissipating energy during a seismic event and then replaced, have continued to gain popularity with designers and improve the resilience of buildings. “This innovation represents a significant shift from traditional methods of enhancing ductility in earthquake design. Instead of merely adapting existing practices, replaceable fuses offer a new paradigm for building resilience,” said Dorian Adams, Senior principal and President with Reaveley Engineers. Adams said fuse technology like buckling restrained braces (BRBs) have been available and widely adopted for several decades. Newer proprietary systems like Durafuse, among others, for moment frames have been gaining popularity. “New technologies are emerging that offer exciting possibilities. One such innovation is the SpeedCore steel shear wall with a concrete core, which is included in the new AISC seismic provisions, the 2022 edition. This technology represents a significant advancement in seismic design,” said Adams. Replaceable fuse technology is also being employed with mass timber construction as interest in and use of the material around the world continues to grow. Jordan Terry, Principal at KPFF Consulting Engineers has designed structural systems for several mass timber and mass timber hybrid projects such as the ICCU Arena at the University of Idaho in Moscow and the recently completed Portland International Airport Terminal Core Redevelopment with its 400,000 sq ft mass Cross Laminated Timber (CLT) roof. He said there have been important advances recently in seismic systems for mass timber structures. “Typically, when you get a mass timber building over five stories you have to look at the seismic reinforcing and that is where you introduce something other than just timber. You might have a concrete core with the elevator shafts or use BRBs,” Terry said. “We had a client in Portland that absolutely wanted to use as much timber as possible. We helped develop a new system called a rocking CLT core wall. The base of the shear wall panels isn’t connected to the ground and it can rock back and forth but there are energy-dissipating sections or fuses, between the panels. They are very ductile. You swap them out and it’s as good as new.” David Dunn, CEO and principal at Dunn Associates, said the firm had utilized a rocking CLT shear panel in their design for a new all mass timber building currently under construction for the Zion National Park Discovery Center at the national park’s east entrance. Terry also said the firm was assisting researchers at the University of California San Diego in developing more all-timber lateral systems but noted like all materials, it should be used for its strengths. “CLT is really strong and stiff so you’d think it would be great for seismic reinforcement, but it is not very ductile,” he said. “We have a project in Spokane [Washington] where we used BRBs. We are letting the wood be stiff and strong like it wants to be and letting the BRBs deal with dissipation.” Hofheins noted mass timber research is going on here at the University of Utah as well. Dr. Chris Pantelides and the U of U’s Department of Civil and Environmental Engineering are developing a BRB encased in timber. Adams noted Dr. Pantelides’s project is not the only fuse research underway locally. “One such project involved a device placed in the middle of an X brace, with elastic braces and a fuse at the intersection of the diagonal braces. This device would compress and stretch, cycling through combined flexure and shear,” he said. “A University of Utah PhD candidate recently further enhanced this concept in his dissertation, adding curved plates of steel that cross one another and engage in tension only after reaching a certain threshold of displacement. This supplemental strength activates only when needed, providing a dual-level design solution that accommodates different magnitudes of earthquakes. The idea of replaceable fuses holds significant potential for the future of structural design. These innovations will become an integral part of performance-based seismic design, offering tailored solutions for varying seismic events. Simpson's Yield-Link connection is another example of this technology, although it is currently more suited for smaller applications.” Dunn said making buildings resilient and potentially reusable quickly after a seismic event not only has implications for safety but for sustainability as well. “Designing resilient structures is really an environmental consideration that is undervalued in my view,” said Dunn. “Code-based buildings will undergo massive deformations and damage after an earthquake. Sometimes small, incremental increases in first-costs can make huge differences in anticipated building performance, salvaging buildings that would otherwise be landfilled. That is a huge environmental impact, but not as buzzy as bike racks, low-water urinals, solar panels, etc.”

Ports? In landlocked Utah? Sure, the traditional idea of a port in Utah, with cargo ships, cruise liners, container cranes, dockworkers, barges—not to mention coastal water—is farfetched. But the Utah Inland Port Authority (UIPA) has broadened the meaning of a port since its formation in 2018. Even without a coast, UIPA has worked to strengthen rail, air, and road cargo infrastructure to turn Utah into a 21st century logistics hub and changing the economic trajectory of the Beehive State in the process. It’s been seven years of increased industrial development that has been a boon for the A/E/C community, but more importantly the logistics and manufacturing network to build for an ever-growing consumer demand. There have been plenty of detractors to UIPA, especially as it relates to ecological conservation. Ben Hart, Executive Director of UIPA, has heard it loud and clear as he sets the organization on a path to aid in development goals that benefit the entire state and the values Utahns hold dear. Origin Story + Coordinated Efforts UIPA was created to pioneer and implement strategic and sustainable logistics-backed economic solutions that enhance the lives of Utahns and establish Utah as a global industry connector. While UIPA began its journey overseeing 16,000 acres in the northwest portion of Salt Lake County, the Northwest Quadrant, it has grown in area and emphases since 2018. Today, UIPA is associated with 110,000 acres in 12 project areas across the state. Most importantly for the organization, Hart said, is how developments within UIPA project areas create high-paying jobs to strengthen Utah communities. Where regional logistics infrastructure does not exist, UIPA can make strategic investments to unlock regional economic growth. “Part of the [UIPA] charter is developing projects that provide economic strength for their entire region. Regional projects need regional infrastructure, which most importantly includes transportation infrastructure,” said Hart, detailing UIPA tools to build out transportation infrastructure intended “to help grow the entire regional economy. Hart said that UIPA has grown its overall area scope to help meet statewide initiatives from current Governor Spencer Cox and regional initiatives from municipal leaders around the Beehive State. Speaking specifically of many of Utah’s rural counties, “There is more commerce going on in those areas than what people recognize,” Hart said, “and you still have a really good workforce in those areas as well.” Municipalities and counties of all levels (see project area map) have been willing to go through a four-step process to access UIPA capabilities in route to industrial development and the high-wage jobs that come with it.