Posts

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

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.

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!

The Aftermath of the Big One

Building Damage – Concepcion, Chile 2010

Building Damage – Concepcion, Chile 2010

Collapsed Bridge – Route 5 – Chile 2010

Collapsed Bridge – Route 5 – Chile 2010

Tsunami Building Damage – Japan 2011

Tsunami Building Damage – Japan 2011

Tsunami-Damaged Sea Wall, Geotechnical Engineer Allison Pyrch – Japan 2011

Tsunami-Damaged Sea Wall, Geotechnical Engineer Allison Pyrch – Japan 2011

Investing in “resiliency” now can make the difference between thriving or not recovering at all.

To be resilient is to be able to restore to a strong, healthy, and/or successful state within a short period of time after experiencing misfortune or change. Because many global communities have recently experienced a string of natural disasters, we are now considering how “resiliency” applies to society and our infrastructure and, of course, we’re asking about our own communities in the Pacific Northwest. How will we fare after a major natural disaster?

The Pacific Northwest is reasonably resilient when it comes to storms, flooding, and landslides—all natural occurrences we have dealt with on a regular basis. Our public agencies have well-tested plans to get basic, and then full services up and running within hours or days. However, the current projections for damages due to global warming or earthquakes and tsunamis are not so optimistic. Based on the most current data, the Pacific Northwest is overdue for an 8 to 9 magnitude subduction zone earthquake and the resulting tsunami, much like those that hit Chile in 2010 and Japan in 2011. Based on evaluations recently completed by Oregon and Washington, widespread damage and casualties are anticipated. Deaths due to collapsing unreinforced or under reinforced masonry and concrete structures are anticipated including those in many historic downtown areas, schools, and public buildings. Widespread damage to utilities and infrastructure is also expected.

The resiliency plans passed by both Oregon and Washington legislatures predict these specific things:

  • Utilities—including electricity, water, wastewater, and natural gas services—will be out for months, if not years;
  • Our aging transportation infrastructure (already rated poor under normal conditions) will not perform well during the design seismic event; and
  • Total destruction is anticipated in tsunami inundation areas.

Both reports indicate that as things now stand, the Pacific Northwest is not seismically resilient. Not by a long shot.

Achievable?

Getting to “resilient” is a formidable and expensive task for communities. The Cascadia scenario includes an overwhelming list of damage and problems that seems impossible to solve in a timely way, especially given current funding challenges. However, the scale and complexity of the problem does not allow communities to ignore the problem altogether. The Oregon and Washington resilience plans proposed a timeline of 50 years to significantly increase the region’s sustainability, and have proposed putting seismic resiliency at the forefront of planning for the states. The Oregon Department of Transportation (ODOT) and Washington State Department of Transportation (WSDOT) have both started down the path to resiliency.

Having recently completed a large-scale evaluation of their systems, ODOT developed a prioritization plan based on infrastructure quality, the anticipated damage, and public priorities after a Cascadia event. They incorporated this into their overall master improvement plan. As funding becomes available, seismic considerations are now included in design, and repairs and upgrades are completed in a manner that will create large resilient sections of their systems. Further, with their seismic evaluation and agency resilience plan in place, they are in a good position to apply for funding to continue needed upgrades. This model is a good example for other public and private organizations in making resiliency an affordable and attainable goal.

Another idea to consider is how resiliency relates to sustainability. Sustainability has been ingrained in our society and almost every public and private entity generally has a person or position that is responsible for facilitating sustainability. Private and public entities put money into sustainability and it is valued by consumers. But the real question is: Can we be sustainable without being resilient? If a new sustainable building is constructed with the intention of saving additional costs over a 20- to 50-year period (we anticipate the Cascadia earthquake within that time frame) and the structure is not designed to be usable after the quake, can it really be considered sustainable?

The cost of not being resilient deserves serious consideration. If seismic resiliency is not addressed in our long-term planning, our region will not recover from the Cascadia event. Businesses will fail or leave; many residents will also choose to move instead of rebuild; and without the tax base, local agencies will be hard hit and will have trouble rebuilding. The currently booming towns of Seattle and Portland will no longer be destinations for travel or for business.

The path forward—what can we do?

As engineers and scientists who are well educated in the failings of our current infrastructure and our seismic hazard, it is our responsibility to educate the public so that resilience—especially seismic resiliency—becomes a priority. In looking at ways to make resiliency a priority, it is valuable to consider what the resiliency movement can learn from the success of the sustainability push. Engineers, architects, and planners need to find a way to educate the public about seismic risks and to make resiliency something that people understand and are willing to spend money to achieve. When projects are in the planning stages, the additional cost to design the structure for resilience should be factored into the cost analysis. Further, creating a LEED-type rating system for resiliency and seismic safety should be considered. If office buildings, homes, and apartment buildings have resilience or seismic safety ratings, consumers and business owners would start to demand and be willing to pay for the real estate with higher ratings. If a business rents a space that can be used within a week after the expected earthquake, even on emergency systems, it would be significantly more valuable and allow commerce to continue after an emergency.

Statewide resiliency plans, as well as the national push for resiliency after Hurricane Sandy, have brought attention to our lack of resilience as a society. In Oregon and Washington, where the Cascadia event is imminent, resiliency is becoming a more focused goal. Hart Crowser has put together a team to help agencies and private organizations evaluate their resiliency with regard to the Cascadia subduction zone earthquake and tsunami. The team includes an architect, structural engineers, planners, emergency managers, public involvement specialists, and experts in finding funding for projects such as these. We are working with private and public organizations to put proposals together to help evaluate and develop resilience plans on a smaller scale. These plans can be used to apply for funding and be incorporated into master planning initiatives so that resilience becomes a reality.

In addition to this planning, as professionals who are responsible for the design in infrastructure, it is our responsibility to educate the public, as well as our clients, on the risks of not being resilient. A few ways this can be accomplished are:

  • Discussions with public and private clients on the additional cost and benefits of designing new and rehabilitated structures to be resilient beyond code requirements, so that they are resilient beyond the standard life safety requirements of the building codes;
  • Support for legislation and laws that require seismic upgrades and provide funding for resiliency;
  • Support for development of a LEED-like rating system for resiliency of structures and other measures to make “resiliency” the new buzz word in real estate and infrastructure spending; and
  • Education of the public about infrastructure risks and the need to become resilient.