Stream Restoration Certification Program Fills Pressing Need

Case Study Presentation

Brad Hermanson and Timmie Mandish present a stream restoration case study.

Fish habitat across the country has been seriously impacted from years of human activity.  There is considerable effort now being made to repair the damage done and improve the chance for fish survival. There is a pressing need for professionals trained and certified in stream restoration.

To meet the need, Portland State University (PSU), in concert with several resource agencies, created a stream restoration certification program.  The one-year program, with five core and a number of elective courses, is the only one of its type in the country.  Started in 2006, the stream restoration program has certified over 160 students in advanced concepts of stream restoration.

Brad Hermanson, Hart Crowser’s Manager of Environmental Sciences and Engineering, co-leads the three-day core course “EPP 225 – Restoration Project Management” with Timmie Mandish of USDA-Natural Resources Conservation Service.  EPP 225 covers topics ranging from fundamentals of project management and project risk management, to contracting strategies, regulatory permitting, construction options, and real-life case studies. Besides co-leading the course, Brad teaches the first half-day kickoff portion, introducing the students to concepts on project management and project risk management.

This year’s EPP 225 course was offered at PSU December 5-7.  There were 32 students, most employed by state and federal natural resource agencies, but also several independent consultants and contractors.  Review comments from the students were very positive.  One student noted “Definitely exceeded my expectations. I’m a scientist.  I tend to underestimate how essential project management is.  The class gave me crucial skills that will probably be serving me in the future.  I learned a ton!  Thank you so much.”  Another stated “…was great to combine project management with the river restoration lens.  I have a PM background and this helped to hone those skills – reminders and tools to communicate, evaluate risk, prepare for unique (project) changes – all are very useful and will strengthen me in my career.”

Course participants

32 students, including state and federal natural resource agency employees, attended the 2017 course.

There’s a Volcano on our Project Site

Water is the life blood of any city, but its systems are not always pretty. So the two-million-gallon Forest Park Low Tank was embedded into the hillside to preserve the natural character of the area and leave unfettered views. However, this presented engineering challenges. Overcoming those challenges helped us win a 2017 Grand Award from the American Council of Engineering Companies (ACEC).

Wait—What’s Down There?

The subsurface conditions were quite unusual. Maps showed them as hard volcanic rock, but our geotechnical explorations discovered a new volcanic vent, as yet unmapped. Although of great interest to geologists, volcanic vents are rarely built on. A search of case histories did not find any information to guide the process. We embarked upon an exploration and laboratory testing program to determine if the 100-foot plus pile of cinders would support the tank. We determined that the cinders were fairly uniform across the area, resulting in uniform support for the tank. Our testing further determined the magnitude of loading the cinders could support. With this information we were able to design a foundation that did not require expensive subgrade improvements or pile foundations.

Our high-tech analyses confirmed a low-tech approach would work.

Burying Infrastructure to Preserve the Natural Beauty

In many places, water tanks are constructed within large cuts that many may view as eyesores and which permanently remove natural habitat. This has been accepted over decades as a necessary compromise to provide a robust water supply to our cities. However, this compromise does not need to be accepted. Much like the trend of burying power, communications, and other utilities that were once also overhead, the Forest Park Low Tank demonstrates that water infrastructure can be adapted similarly.

Making the Water Supply Safe

Water is a critical resource in any disaster that disrupts our infrastructure. It’s common knowledge that we cannot survive for more than three days without water. During any natural disaster, it is imperative that our water remain safe and accessible. We completed a site specific seismic hazard (SSSH) as part of our work, so the tank and appurtenant facilities will withstand the next “Big One.”

Defining Ingenuity

Sometimes ingenuity is not devising something new, but applying simple methods to solve a problem. We used performance-based results to guide changes in shoring design, and confirmed landslide mitigation approaches during construction. We avoided designing expensive foundation alternatives, installing bulletproof (and expensive) secant shoring walls, and over-analyzing slope stability prior to construction. And then we buried our best work.

The one thing to remember about this project is that we did not blow our top over an unexpected volcanic vent; instead, we persevered and worked with the design and construction teams to build a successful project…and then buried it out of “site.”Finished project

The Game of Thrones Wall—An Engineering Perspective

Game of Thrones Wall

Photo: HBO

The Game of Thrones (the HBO series based on George R. R. Martin’s books, A Song of Fire and Ice) features a giant wall made of ice. Seven hundred feet high. It’s an imposing structure, but it has to be, in order to keep out the terrifying dead people who inhabit the north.

According to Martin, “You could see it from miles off, a pale blue line across the northern horizon, stretching away to the east and west and vanishing in the far distance, immense and unbroken. This is the end of the world, it seemed to say.”

Such an extraordinary structure couldn’t help but draw attention from our geotechnical engineers and staff, who responded to some of the quotes from the books.

“The wall is a hundred leagues long.”

A league was supposed to be the distance that a person could walk in one hour. An English league, once upon a time was about three miles long, which would make the wall three hundred miles long.

“The wall is 700 feet high.”

This is almost as tall as the 1201 Third Avenue Building in Seattle, a 55-story building, which coincidentally has beautiful blue coloring as well. Certainly it takes a lot of work to design and build a high-rise—imagine building so many adjacent high-rises that they would stretch for 300 miles. That’s never been done.

At a height of 700 feet and a unit weight of 57.4 pounds per cubic foot (pcf) for fresh water ice, the base contact pressure on the underlying soil/rock would be on the order of 40,000 pounds per square foot (psf). (Compare that to a high-rise on glacial till at 14,000 psf).

“The wall has stood for, what, eight thousand years?”

Assuming a coefficient of secondary compression, C-alpha, of 0.02 and assuming that the base upon which the wall is built is comprised of some reasonable thickness of compressible organic muskeg (say ten feet), and assuming the wall was built over a period of one hundered years, the wall will likely have settled about three to five feet under its own weight.

“The top wide enough for a dozen armored knights to ride abreast.”

How wide is an armored knight? Say five feet? 5 x 12 = 60 feet wide? To safely travel, there would need to be at least three feet between riders so the total width (including four feet on either side for shoulders and jersey barriers) would be 101 feet.

“The gaunt outlines of huge catapults and monstrous wooden cranes stood sentry up there, like the skeletons of great birds, and among them walked men as small as ants.”

To anchor the catapults and cranes, it is likely that the overturning and uplift forces on the catapults and cranes would control the design. The overturning forces associated with the action of the catapults and the wind loads on the structures (resulting from the unobstructed exposure to the predominant winds due to the height of the wall) could be resisted by using high-capacity drilled micropiles.

“It was older than the Seven Kingdoms and when he stood beneath it and looked up, it made Jon dizzy. He could feel the great weight of all that ice pressing down on him, as if it were about to topple, and somehow Jon knew that if it fell, the world fell with it.”

One of the Seattle-Tacoma International Airport Third Runway walls (135 feet tall) was built stepped in, in order to avoid this feeling when you stand at the base of it. However, typically, a tall wall looks shorter when looking up than when it does when looking down. Jon is a weenie.

“Eight hundred feet above the forest floor, a good third of that was earth and stone rather than ice.”

It seems that people got creative over the years, sometimes making use of on-site materials, a good practice to save cost, time, and the environment. It also makes sense, when you are building a structure with a contact bearing pressure equal to 40,000 psf, to do overexcavation and replacement with densely compacted (i.e., 95 percent of the maximum dry density, within two percent plus or minus of optimum moisture content, as determined by ASTM D1557 Test Procedure) well-graded sand and gravel with less than five percent passing the U.S. No. 200 sieve based on the minus three-quarter-inch fraction.

Have questions about the geotechnical design of other giant structures? Need a dragon or two? Contact Garry “the Hound” Horvitz.

Towering Hills for Beauty and Strength

Governors Island

Photo: Timothy Schenk

A dozen years ago an American port representative was asked how his port was preparing for rising sea levels. “Well…we aren’t,” he answered, somewhat sheepishly, because he knew they should be. Back then, the public was skeptical of the controversial topic, and frankly many ports had too many other priorities. But now public officials see the situation in a new light. They are taking advantage of waterfront development projects to make property not only more resilient to climate change, but also more beautiful and beneficial to the public.

A perfect example is the 40-acre Governors Island Park and Public Space in New York. West 8, an urban design and landscape architecture firm, transformed the abandoned former military island into a green oasis with an extraordinary 360-degree experience of water and sky that has won numerous awards. Part of the makeover involved creating four tall, dramatic hills from twenty-five to seventy feet high. This meant overcoming a major challenge involving Governors Island history.

Governors Island Park and Public Space

Pumice, or lightweight fill (the light colored material) is placed on the water side of the tallest hill. Image courtesy of West 8

From Subway Dirt to Island

Back in 1637, when a Dutch man bought Governors Island for two ax heads, a string of beads, and some nails, the island was only about 72 acres. In 1901, somebody needed a place to discard the dirt from the excavation of New York’s Lexington Avenue subway line. What better place to put it than Governors Island? The dirt widened the island by 100 acres.

Fast forward to the twenty-first century. Now that the island had been sold back to the people of New York for one dollar, it was possible to take advantage of the island’s potential views, which meant building upwards. To create the new hills, West 8 needed to add 300,000 cubic yards of new fill—enough to fill 40 Goodyear blimps. The challenge was to keep that massive amount of dirt from pushing the island built on subway fill out into the harbor.

Hart Crowser worked with the lead civil engineer to make the hills strong yet light. Twenty-five percent of the new fill is from the demolition of structures and parking lots. This made it sustainable and strong. Pumice lightened the load. Some of the fill was wrapped in geotechnical matting, and the steepest slopes used wire baskets. This allowed hills as high as seventy to be built within twenty feet of the shoreline, and allowed for varying slopes and walkways, where the public can safety enjoy the park.

Governors Island reopened to the public on May 28.

Anchoring the World’s Longest Floating Bridge

SR520 Bridge

Photo: WSDOT

You’re at the bottom of Lake Washington, 200 feet underwater. It’s flat as a pancake here, but the first 50 feet of soil is diatomaceous silt and clay, which is unspeakably unstable. Think microscopic glass Christmas tree ornaments with the consistency of chocolate mousse. Below that is 50 feet of very-soft clay (zero blowcount, to those in-the-know).

Try, just try, to anchor the new SR 520 Bridge in this chocolate mousse (remember, it’s a floating bridge that can’t be left to drift off to Renton or points unknown). And just for good measure, make each of the 58 anchors able to resist a horizontal load of 600 tons—four times what was needed for the old bridge.

Figure out that you’ll need three types of anchors. In areas along the side slopes, where the water is shallower and has competent soil, use a gravity anchor, but call it a box of rocks amongst your workmates.  Build it like a heavily reinforced concrete egg carton with only four compartments. Joke about the kind of eggs that would fit into a 40 foot by 40 foot by 23 foot carton.  Build them on a barge at the concrete plant in Kenmore at the north end of the lake.  Make them so heavy that that the only derrick large enough to lift one is too big to fit through the Ballard Locks. Tow the gravity anchors through the Ballard locks, though they barely fit, while the public looks on in astonishment.

Gravity anchor

Gravity Anchor on its way to the SR 520 Bridge site. Photo: Kiewit

Flood the 440-ton floating boxes with water to make them sink. Lower them to the lake-bottom and place them on a leveled-out gravel pad. Fill each of them with 1,700 tons of rock to make them heavy enough for lateral frictional resistance, or so they won’t budge.

Don’t stop there. Use a second type of anchor, a drilled shaft, along the shoreline where the lake is shallow enough that the box of rocks would have caused havoc as a navigational hazard. Make them ten feet in diameter and 100 feet tall, not as tall as the original Godzilla, but close enough.

Drilled Shaft

Ten-story-deep drilled shaft anchor. Image: KPFF Consulting Engineers

Then, use fluke anchors, the most technically challenging anchor, for the majority of the project. Make these fluke anchors from reinforced concrete plates three feet by 35 feet wide by 26 feet tall. Cast a steel tetrapod into the side so that the anchor cables can be attached to the I-bar at the end of the tetrapod. Explain that a “tetrapod” is a four-sided shape with triangular faces (not to be confused with a four-limbed vertebrate).

Fluke Anchor

Fluke anchor being jetted into the bottom of Lake Washington. Image: KPFF Consulting Engineers

Place the fluke anchors in a steel frame equipped with water jet tubes to drive them into the mud. Because the mud is chocolate mousse, place mounds of rock above and beside the fluke anchors. And then more rock. And then more rock. Good, that’s enough.

Now, celebrate. The Washington State Department of Transportation’s grand opening of the longest floating bridge in the world will be April 2 and 3, 2016. You can run, bike, or possibly meander across the bridge. Hopefully there will be food. You’re hungry after all that work.

Hart Crowser was the geotechnical engineer-of-record for the anchors for the new SR 520 Bridge. The design-build contractor was a joint venture of Kiewit/General/Manson. The structural engineer was KPFF Consulting Engineers.

Need more detail? Read the technical paper Geotechnical Design: Deep Water Pontoon Mooring Anchors or contact Garry Horvitz, PE, LEG, at garry.horvitz@hartcrowser.com

Fluke anchors on barge

Fluke anchors on barge.

Why an Earthquake Warning System Should Not Be a Priority In The Pacific Northwest

Earthquake_damage_Cadillac_Hotel,_2001_SmallerThe newest and hottest topics when it comes to disaster discussions in Oregon and Washington, as well as on the national level, are an earthquake warning system and earthquake prediction possibilities. They are the new obsession that has come on the heels of the New Yorker articles this summer. While we don’t object to advancing both of these methods to better warn of impending quakes and hopefully save lives, we do think that the discussion is premature, especially here in the northwest.

The first reason is that an earthquake warning system like that in Japan has to be implemented only with a comprehensive, aggressive, and continuous public education program. Without a full understanding of what you should do when your phone emits an ear piercing shriek warning of impending shaking, we risk even greater panic and possibly more casualties. Running out of buildings with unreinforced masonry or weak facades just before the shaking could put people at more risk of falling hazards outside of the buildings. It could also cause major traffic hazards as drivers try desperately to get across or get off bridges and overpasses. Unless we develop a much better awareness of what the public should do when they receive the warning, it may cause more problems than it solves.

But the real issue is that these technologies are acting as the bright shiny objects that are distracting all of us, from the public to the president, from the real issue: our infrastructure is in dire need of upgrades not only to prevent casualties, but also to encourage long term recovery.  We doubt 30 seconds of warning will seem as beneficial when the public doesn’t have wastewater for one to three years.  Further, a warning system that stops surgery or an elevator is not as important as making sure that the hospital or building itself is designed to withstand shaking. Especially in Oregon and Washington, all of our energy and funds need to be focused first on comprehensive and intelligent infrastructure improvements that increase our community resilience. And that needs to happen as quickly as possible. We implore you not to follow the flashing light! Urge our government to focus on the real issues, and encourage your colleagues and neighbors to personally prepare.

For more information contact Allison Pyrch at (360) 816-7398 or Allison.pyrch@hartcrowser.com

How Many Soil Borings Do Development Sites Need?

One of the challenges that developers – both public and private – face from a geotechnical and environmental standpoint is the inherent uncertainty in what’s underground at the development site. Generally, we’d like to know the geologic layers, soil types, groundwater levels and potential environmental contaminants across a site. But trying to characterize a fairly large volume of soil with just a few pieces of information inevitably leaves knowledge gaps.

An illustration for this challenge comes from an unexpected source – a children’s book. “Sam & Dave Dig a Hole,” written by Mac Barnett and illustrated by Jon Klassen, is a funny, deadpan story about two boys (and a dog) who dig a hole, hoping to find “something spectacular” (website here). 

Sam and Dave Dig a Hole

Photos courtesy of Mac Barnett and Jon Klassen

As the boys dig through the ground, they come close to, but never discover, several spectacular gems.

Sam and Dave miss the gem

In fact, they seem to navigate around everything spectacular.

Sam and Dave digging around the gem

While the book is an admittedly whimsical analogy to geotechnical and environmental subsurface exploration, it actually serves to illustrate an important point – there may be more beneath the surface of a site than a couple of borings will indicate. Skimping on borings increases the chances that zones of contamination or soft soils, may be missed, only to be discovered during or after construction. More borings can help fill in gaps and increase confidence that the site has been well-characterized. In many cases, spending bit more money on site exploration may reduce overall project costs by reducing uncertainty about the site and what may be encountered during construction. And depending on project needs and site conditions, the use of less conventional site investigation methods (Cone Penetration Test, strataprobe) may be appropriate. These can often provide better spatial coverage at similar costs to traditional Standard Penetration Test borings, because they’re cheaper. 

Of course, there’s no one-size-fits-all approach to subsurface exploration. The best exploration program for a project will balance project needs, budget, and local experience with geologic conditions. But in order to minimize the chances of pulling a Sam and Dave, maximizing spatial coverage in the explorations program should be a consideration.

Shaken and Stirred: Northwest Earthquake and Tsunami

Washington 9.0 earthquake--Are you ready? Oregon 9.0 Earthquake--Are you ready?Suddenly the Pacific Northwest is on the national stage for its earthquake and tsunami vulnerability, thanks to a New Yorker article. “The Really Big One,” by Kathryn Schulz, has triggered attention from dozens of local papers and news sites. Yet even before the New Yorker shook the Northwest (pun intended), Oregon Public Broadcasting had been featuring Hart Crowser engineer Allison Pyrch in its “Unprepared” series, to alert the region to the impending disaster in hopes that we will get prepared.

Also, Allison recently gave a presentation for the Lake Oswego Sustainability Network: “Surviving a 9.0, Lessons Learned from Japan and Beyond.” If you are involved in emergency management or just plain interested in massive disasters and their aftermaths, settle in for some powerful visuals and easy-to-follow explanations about earthquakes in Japan and Chile, how the 9.0 earthquake and tsunami will happen in the Pacific Northwest, and what you can to do to be resilient.

Watch the whole “Surviving a 9.0” video to get unusual insight into what’s ahead, or if you’re pressed for time, skip to one of these minute points:

  • 9:00 Jan Castle introduces Allison Pyrch 10:56 Allison Pyrch’s presentation begins with how the Pacific Northwest 9.0 earthquake will happen
  • 14:25 Comparing the Japan and Chile quakes “It didn’t stop shaking for a day”
  • 21:45 Fire damage/natural gas 22:30 Water, wastewater, and electrical systems; liquid fuel; natural gas
  • 24:25 Lifelines/infrastructure/airports “PDX will not be up and running”
  • 28:35 Port damage/economics
  • 31:45 How prepared is the Pacific Northwest? When will it happen? “We are 9 ½ months pregnant”
  • 35:00 What will it look like?
  • 37:32 What you can do
  • 40:30 What businesses can do
  • 42:11 Can you be sustainable without being resilient?
  • 43:33 What about a resiliency rating system similar to LEED?
  • 53:30 Will utilities, transportation, hospitals be useable after the 9.0? “We’re toast”
  • 1:01:30 End of Allison’s presentation; additional information from Jan Castle on how to prepare
  • 1:19:19 How sustainability measures in your home lead to resiliency

First Tsunami Safe Haven Building in the United States

Ocosta School Construction

The City of Westport stands sentry at the tip of a narrow peninsula between the expanse of the Pacific Ocean and the protection of Grays Harbor. The Cascadia Subduction Zone, a 700-mile-long earthquake fault zone, lurks approximately 90 miles off the shore. Experts predict this submerged fault zone will release a magnitude-9.0 earthquake and unleash a tsunami that will hit the coasts of British Columbia, Washington, Oregon, and California. The last such “megaquake” struck just over 300 years ago.

As was recently seen in Chile, Indonesia, and Japan, tsunamis ravage low-lying areas such as Westport. There, it is expected that a tsunami from a Cascadia Subduction Zone megaquake could reach the coast in as little as 20 minutes. However, evacuation of Westport and neighboring Ocosta Elementary, Junior and Senior High Schools could take nearly double that time. Therefore, in 2013 residents of the Ocosta School District approved re-construction of an aging elementary school that will include the nation’s first tsunami “refuge” structure.

Construction of the school started in November 2014. The school’s gym has been designed to withstand the impact of a tsunami and the debris it carries, while sheltering nearly 1,000 people on its roof. The roof is 30 feet above the ground (nearly 55 feet above sea level) to keep people dry and safe. The gym’s roof is supported by heavily reinforced concrete towers in each corner that are designed to remain intact during shaking from the initial megaquake, associated aftershocks, and the resulting tsunami surges.

Because of the potential for over 10 feet of scour (soil erosion adjacent to the building) caused by tsunami surges and liquefaction of the native sandy soils, the gymnasium is supported on nearly 50-foot deep piles. The remainder of the school is supported on shorter piles designed to withstand earthquake shaking and liquefaction, but not necessarily tsunami surge forces.

Links below lead to more information on the Ocosta building and general tsunami research. Note that the maps on the last link (Project Safe Haven) illustrate how impossible it would be to escape a tsunami in the Ocosta area.

Rooftop Refuge Washington Disaster News, Washington Military Department Emergency Management Division
Grays Harbor County school to build first U.S. vertical-tsunami refuge Seattle Times
First tsunami-proof building to be built in Westport Komo News
Rising above the risk: America’s first tsunami refuge the Geological Society of America
Project Safe Haven: Tsunami Vertical Evacuation in Washington State

Oregon Public Broadcasting’s Resiliency Blitz Starts January 26

Allison Pyrch of Hart Crowser

Allison Pyrch at a base isolated hospital near Ishinomaki, Japan, talking to Ed Jahn, OPB Producer. With Jay Wilson, Clackamas County Emergency Manager (left) and the hospital engineer. Listen January 26-28 on OPB radio’s Morning Edition between 7 and 9 am and at www.OPBnews.org.

For the last year, Allison Pyrch, a geotechnical engineer with Hart Crowser in Portland, Oregon has been the American Society of Civil Engineers representative to support Oregon Public Broadcasting in the preparation of a 2015 “media blitz” highlighting Oregon’s dire need for improved seismic resiliency.

Allison, the section secretary and a member of the ASCE Technical Committee on Lifeline Earthquake Engineering, travelled to Japan with the OPB Field Guide crew in September to highlight the damage and engineering successes that were observed after the 2011 subduction zone earthquake and tsunami.

The Japan footage, as well as footage from within Oregon, will be used throughout the year to bring awareness to the need for seismic resiliency here at home. The work will culminate with an hour-long documentary in October 2015.

The first segment of coverage will air January 26-28 on OPB radio’s morning Edition between 7 and 9 am can be found now on the OPB website here and here. The series will discuss critical structures in tsunami zones. The January 28th segment will feature Allison and cover how Japan constructs base isolated hospitals that are ready for business immediately after a major seismic event. Tune in and listen!