Building Success

Shannon & Wilson, Inc., a geotechnical engineering and environmental consulting firm based in Seattle, Wash., is known for innovation and technical expertise. It's a tradition that began with the two men who started the company in 1954, Bill Shannon and Stanley Wilson.
"I think it really goes back to both of our founders, but in particular Stan Wilson, who was quite an innovator and had multiple patents," said Dr. Kathryn Petek, a geotechnical engineer with Shannon & Wilson. She notes that the slope inclinometer, which continues to be a key source of geotechnical data in construction today, was actually derived from a prototype built by Wilson in 1952.
"We have a really strong culture of technical excellence. We have a very deep and wide bench of specialists and experts, who span all aspects of geotechnical and environmental engineering," said Petek.
Shannon & Wilson established themselves as a leader in driven piles back in the early 1980s with the West Seattle Freeway Bridge replacement project.
For this project, the company's engineers developed and executed an extensive static and dynamic load test program on instrumented 36-inch diameter open steel pipe piles and 24-inch octagonal, prestressed concrete piles. The results of the load test program led to reductions in production pile lengths and an improved understanding of pile drivability that ultimately resulted significant cost savings for the project.
Over the years, the company has utilized driven piles for many public-sector infrastructure and private development projects. It's an impressive list that includes such structures as the CenturyLink Field Stadium and Exhibition Hall sports complex and the Safeco Field ballpark in Seattle, as well as numerous major bridge, railroad and port projects throughout the U.S. and Canada.
For CenturyLink Field Stadium and Exhibition Hall in Seattle, Shannon & Wilson provided geotechnical engineering and environmental consulting services for the pre-design, design and construction phases of the large sports complex that's home to the Seattle Seahawks of the NFL. More than 1,000 18- and 24-inch closed-end steel pipe piles were required for the project, which was completed in 2002.
In another driven pile application, Shannon & Wilson provided geotechnical and hydrogeologic services for design and construction of a four-acre pontoon casting facility in Aberdeen, Wash.
Completed in 2011, the site was used to build 33 concrete pontoons needed for the new SR 520 Floating Bridge on Lake Washington. The project included more than 900 18- and 24-inch diameter open-end steel pipe piles. The piles were driven and cut-off 30 feet below grade with a specially designed down-hole tool that expedited subsequent site excavation.
Over the last 60-plus years, Shannon & Wilson has witnessed the size of its projects increase. While maintaining roles in small and mid-size projects, Shannon & Wilson has taken on numerous mega-projects, including schedule driven design-build projects with high price tags.
"The projects have become much more complex with [a] higher dollar value," said Shannon & Wilson president Gerard Buechel. "We're now involved in one and two billion-dollar projects."
Buechel maintains one of the keys to the company's success has been the quality of Shannon & Wilson's staff, which numbers around 300 people.
"We like to hire very smart people, and typically once they join our firm they stick around for a long time. For example, I've been here 38 years and there's probably 10 percent of the firm here that's been here more than 30 years; so there's a lot of tenure and expertise," Buechel said.
"I think, in general, we're scientists at heart, and we like to take on the tough, challenging jobs. We've been successful enough to win those kinds of projects, and this keeps people engaged and retained."
Buechel notes that while Shannon & Wilson does much of its work in the Pacific Northwest, the company's market area extends well beyond that. In addition to its head office in Seattle, Shannon & Wilson has 11 other branch offices in Washington, Alaska, Oregon, California, Utah, Colorado, Wisconsin, Missouri and Florida.
"Our motto is 'Have Job, Will Travel', so we are licensed in all 50 states and we've done work in all 50 states," Buechel said.
Shannon & Wilson has a seven-member board of directors that's chaired by Greg Fischer, and it is employee-owned, with over 80 percent of the firm's staff members holding ownership.
"Being able to own part of the company certainly transforms the way we approach our work," said Petek. "I believe it results in a higher level of commitment in the projects we do."
Expert in large diameter open-end steel piles
Petek points out that Shannon & Wilson has become a leader in deep foundation projects that use large diameter open-end steel pipe piles.
A notable example is the Port Mann Bridge replacement project near Vancouver, B.C., Canada. The new bridge is the second longest cable-stayed bridge in North America and, at the time of its completion, its 200-foot width made it the widest bridge in the world.
Shannon & Wilson utilized six-foot-diameter open-end steel pipe piles on the project, which was completed in 2015 with a new 10 lane, 1.4-mile-long bridge spanning the Fraser River. The north and south bridge pylons, along with 10 additional approach piers, were supported by piles driven into very dense, glacially overridden deposits with lengths greater than 230 feet.
"The project included an extensive deep foundation load test program, that included an instrumented static load test on a six-foot-diameter pile to over 12,000 kips," Petek said, adding that this static load test remains the largest ever performed with a conventional load testing frame in North America.
"The static load test, combined with extensive dynamic load testing, enabled the use of higher resistance factors in design. The successful testing reduced the required number of piles by approximately 30 percent and ultimately led to significant cost savings for the project."
Shannon & Wilson supported early applications of large diameter open-end steel pipe piles in the Pacific Northwest, including the WSDOT SR 529 Ebey Slough Bridge replacement project in Marysville, Wash., completed in 2012.
For the Ebey Slough Bridge, four-foot and six-foot diameter piles were driven to depths greater than 220 feet. At that time, the piles were the longest and largest diameter piles driven for a project in Washington State.
Shannon & Wilson has continued to utilize large diameter open-end piles ranging from 36 to more than 96 inches in diameter for numerous other projects, including the Alaskan Way Holgate to King Street Viaduct in Seattle, the Coast Meridian Overcrossing in Vancouver, B.C. and the Tanana River Bridge in Salcha, Ala.
Shannon & Wilson's innovation in driven piles has led to its role as Co-Principal Investigator on a current Federal Highway Admiration (FHWA) research project on the bearing resistance of large diameter open-end piles.
"This research builds upon Shannon & Wilson's experience with design and load testing of large diameter piles and aims to address some of the uncertainty associated with their design. The project team has used collected static load test data to evaluate static design methods," Petek said.
"Based on the research, the project team has developed new resistance factors specific for large diameter open-end piles and is finalizing design recommendations to be synthesized in upcoming FHWA guidance and ultimately the AASHTO code."
Shannon & Wilson is a relatively new member of PDCA. Petek says her company values the relationships it's already forged since joining the association in 2013.
"We see PDCA as an increasingly important organization for developing connections across our industry and promoting advancements in driven piles," she said.

Posted in PileDriver Magazine. Tagged as Issue 5, 2018.

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