So the fact that the SRC is proposed for unsuitable soils may not be directly relevant to the approval criteria of that Hearing. From here, for a non-specialist, it's hard to fit into the framework of the UGB decision.
Still, the Geology Final Technical Report Addendum is out, as are all the other addenda, and posted to the City website late last week.
It does not inspire confidence. And it seems relevant nonetheless.
ODOT's Big Project on Unstable Soil was a Disaster
|"Ground Anchors" on an unstable hillside,|
for US20 on the Pioneer Mountain to Eddyville segment
But that's a big happy face on an embarrassing and costly mess for ODOT.
From the ODOT timeline:
In 2005, the Design Build contract was awarded to Yaquina River Constructors(YRC) (Granite Construction).About it the Portland Tribune writes:
2006 winter rains caused erosion and sediment to flow into the creeks and streams. This resulted in DEQ fines of $240,000 to the Design Builder and $90,000 to ODOT.
2010 The Design Builder determined that columns at Eddy ‘B’ Bridge were out of plumb. Further investigation determined that the columns at Cougar Creek Bridge were similarly out of plumb. Eventually the Design Builder reported that the four landslide locations were still moving; the landslide mitigation constructed in 2008—the buttresses and shear keys—had failed.
2011 No substantial construction was completed in the sections containing the four landslides and bridges since the continued movement was discovered in early 2010.
In 2012, ODOT and YRC negotiated the end of the Design Build contract and ODOT took over management of the project.
Months before the Oregon Department of Transportation asks the Legislature for a massive increase in taxes and fees to support new spending on roads and bridges, the agency plans to “celebrate” a newly completed project that went $230 million over budget and seven years past the original due date — all to straighten a 10-mile stretch of highway....
[T]he Route 20 project has “been in some very dark spots ... certainly this project had plenty of opportunities to learn.” [says ODOT]
Those “opportunities” included replacing a contractor for allegedly poor work after paying it $162 million, and blowing up four brand-new bridges that cost $17.1 million, according to a four-part investigative series by Winston Ross of the Eugene Register-Guard in 2012. The series quoted documents and observers to pin the blame for the overruns on bad outsourcing as well as ODOT’s practice of awarding projects to the low bidder.
|ODOT: Bridge Demolition for a Do-over|
US 20: Pioneer Mountain to Eddyville
The SRC is also Proposed for Unstable Soils
|The Preferred Alternative is still in a liquefaction zone|
(via N3B, adapted from chapt 3.18 of the DEIS)
The final Geology Final Technical Report Addendum identifies it as crossing the three worst categories of unstable soil:
- Category 5, with greater than 24 feet of estimated thickness of liquefiable material
- Category 4, with 18 - 24 feet of estimated thickness of liquefiable material
- Category 3, with 12 - 18 feet of estimated thickness of liquefiable material
- The geologic conditions and geological resources in the project vicinity could pose challenges to project construction. The preferred alternative could negatively impact the local geological resources and could potentially be impacted by geologic hazards in the project vicinity, both directly and indirectly.
- The project could contribute to impacts in the floodplain including scour, flood potential, and local slope failures. The presence of loose, soft soils, scour, streambank erosion, and earthquake-related issues (such as seismic shaking and liquefaction) could impact the project and require special construction techniques and monitoring during construction.
- The preferred alternative could lead to depletion of geological resources such as earth materials for embankment; durable rock for rip-rap; steel for reinforcing bars and structural members; stone aggregate and Portland cement for concrete; steel and copper for electrical cables and wires; and fuel oil, gasoline, and diesel fuel.
- The preferred alternative would require mitigation measures to ensure safe construction and long-term performance. However, by conducting proper geotechnical investigations, adequate site characterization, and proper engineering design, the project structures could be constructed safely. [italics added]
Even if the Salem River Crossing were necessary (and of course the position here is that it is not), the likelihood of very large cost overruns is so probable that it can be reckoned a certainty.
While ODOT and the City of Salem do a good job on small and medium-sized jobs, ODOT has a terrible track record, and in fact all agencies do, on mega projects. (See Bent Flyvbjerg's research.) There is strong evidence, internal from ODOT and external from published academic studies, that the actual cost of the bridge would be double or triple the initial estimate.
So how do you feel about a bridge that costs $2 or $3 billion after debt service? Is it still a value to you?
The local cost on that would be on the order of $100 or $150 million a year.
For comparison, our 2008 "Keep Salem Moving" Road Bond was $100 million all by itself, and that has funded about 60 different projects of varying size. Bond savings are still being used this year on a new crosswalk near WESD. $100 million is a lot of money!
The Geology Report is Cavalier about Earthquake
There's also some funny math and probability and other balderdash in the report.
The ODOT Geotechnical Design Manual (ODOT, 2015a) defines two levels of seismic design loading for bridge design.What the heck does this mean? Right now in our current geo-historical moment, we know there's a much larger chance than 5% in the next 50 years of the Cascadia Subduction Zone quake. We are due soon for the big one, not hypothetically over some distant future "return period" of 500 or 1000 years. A year-old piece described the probability of an magnitude 8.0 or greater:
Using the location of the site (latitude of 44.95 degrees north and longitude of 123.04 degrees west), the PGA on a rock/stiff soil site (National Earthquake Hazards Reduction Program B-C Boundary) is estimated to be 0.28g (g=acceleration of gravity) for an earthquake with a 5 percent probability of being exceeded in 50 years (an approximately 1,000-year return period) and 0.19g for an earthquake with a 10 percent probability of being exceeded in 50 years (an approximately 500-year return period).
- The ODOT 1,000-year “no collapse” criterion requires that bridges must be designed for a level of shaking that has a 1,000-year return period under a “no collapse” criterion. “…the bridge, bridge foundation, and bridge approach fills within 100 feet of the bridge must be able to withstand the forces and displacements without collapse of any portion of the structure” (ODOT, 2015a). No requirements for serviceability or other limits on the extent of damage are defined for this earthquake.
- The ODOT 500-year “serviceable” criterion requires that bridges must remain “serviceable” for a level of shaking that has a 500-year return period. “… the bridge and bridge approach fills within 100 feet of the bridge are designed to remain in service shortly after the event” (ODOT, 2015b).
The central part of Oregon is on the order of 25 to 30 percent [in the next 50 years]. That's from central Oregon southward, on the coast. Then for southern-most Oregon and in northern California it bumps up a little bit more: 37 to 40 percent.And at least to a non-specialist, the soils over which the SRC would pass are in no ways "rock/stiff."
To a non-specialist, the whole discussion in the Geology Addendum looks like utter nonsense. Just flat out wrong and misleading.
In a 100 year lifespan for a new bridge - that's about what we should build for, right? - the best available information is that the odds of a huge earthquake are better than a 50/50 coin flip in the next century. So anything we plan and build should assume much greater than a 5% chance of an earthquake. Anything we plan and build new from here on out should assume a 100% chance of a huge earthquake!
In Every Way the SRC has Unstable Foundations
The Preferred Alternative as it is discussed in the Geology Addendum looks to be engineered for a mid-sized earthquake only. It doesn't look like it's reinforced to megaquake standards. So there will likely be overruns and it will still collapse!
And to make it actually stable to the megaquake standard would add much, much more, and multiply its already overrun cost.
Even if you think we desperately need the SRC in its present form, the current budget is not realistic and it will cost even more for the class of seismic stability we actually need.
Given those additional costs, is it still worth it?
The answer here is no.
Again, this may not fit easily into the strict framework for evaluating the proposed UGB expansion, but that seems like a fault in the process and its rules, not an irrelevancy. It is not cost-effective or reasonable to plan such a large project for soils known to be unstable in for a lifespan in which we expect a large earthquake.