Burnside Bridge Earthquake Readiness Project

[Jakz]

https://www.oregonlive.com/politics/2025...ay-amid-federal-funding-uncertainty.html

Sigh. I don't understand these figures. The Tillikum Bridge cost $135 million (2014). Seattle's South Park bascule bridge cost $167 million (2012). This bridge is wider than the Tilikum and longer than the South Park bridge. And construction inflation since 2013 is about 100%. But still. These costs are getting astronomical.

[RED_PDXer]

Originally Posted by Jakz

https://www.oregonlive.com/politics/2025...ay-amid-federal-funding-uncertainty.html

Sigh. I don't understand these figures. The Tillikum Bridge cost $135 million (2014). Seattle's South Park bascule bridge cost $167 million (2012). This bridge is wider than the Tilikum and longer than the South Park bridge. And construction inflation since 2013 is about 100%. But still. These costs are getting astronomical.

I agree. how did it go from $900m in 2022 to $1.6 billion three years later? I thought they weren't even planning to keep the bridge open during construction, which should save money. Now the Interstate Bridge Project is looking cheap in comparison, given its size. However, I expect that project to get more expensive as it subject to the same delays due to federal funding.

[urbanlife]

Originally Posted by RED_PDXer

I agree. how did it go from $900m in 2022 to $1.6 billion three years later? I thought they weren't even planning to keep the bridge open during construction, which should save money. Now the Interstate Bridge Project is looking cheap in comparison, given its size. However, I expect that project to get more expensive as it subject to the same delays due to federal funding.

Building materials....thanks, Trump.

[eric cantona]

Originally Posted by Jakz

https://www.oregonlive.com/politics/2025...ay-amid-federal-funding-uncertainty.html

Sigh. I don't understand these figures. The Tillikum Bridge cost $135 million (2014). Seattle's South Park bascule bridge cost $167 million (2012). This bridge is wider than the Tilikum and longer than the South Park bridge. And construction inflation since 2013 is about 100%. But still. These costs are getting astronomical.

Tariffs and inflation, yes. But understand that this bridge is being designed to survive a massive earthquake.

[Jakz]

Originally Posted by eric cantona

Tariffs and inflation, yes. But understand that this bridge is being designed to survive a massive earthquake.

Construction inflation--generally tariffs, overall inflation, and higher wages--is around 100% over the last decade, if the Mortenson index is to be believed. Even factoring that in, this bridge is still two or three times more expensive on a per-square-foot basis.

Both the Tillikum and South Park bridges were designed to modern codes, including seismic loading, so costs should be fairly comparable. And in general the added cost of designing a new structure to resist earthquakes is small, in the 5-10 percent range (unlike retrofits which are hideously expensive). I'm sure the immediate usage designation adds some cost, but again I don't think it would be a major cost driver.

w.r.t the IBR...yeah, the $7.5 billion estimate is from 2022, the same year of the $900 million estimate for this bridge. If costs are doubling...that project could be headed towards a ludicrous $15B.

[eric cantona]

Originally Posted by Jakz

Construction inflation--generally tariffs, overall inflation, and higher wages--is around 100% over the last decade, if the Mortenson index is to be believed. Even factoring that in, this bridge is still two or three times more expensive on a per-square-foot basis.

Both the Tillikum and South Park bridges were designed to modern codes, including seismic loading, so costs should be fairly comparable. And in general the added cost of designing a new structure to resist earthquakes is small, in the 5-10 percent range (unlike retrofits which are hideously expensive). I'm sure the immediate usage designation adds some cost, but again I don't think it would be a major cost driver.

w.r.t the IBR...yeah, the $7.5 billion estimate is from 2022, the same year of the $900 million estimate for this bridge. If costs are doubling...that project could be headed towards a ludicrous $15B.

This is not being designed to modern seismic codes. It is being designed to remain standing and USEABLE after the inevitable Cascadia mega earthquake. It is being called a "lifeline route". It will be the first such bridge in Portland.

[PhillyPDX]

Originally Posted by eric cantona

This is not being designed to modern seismic codes. It is being designed to remain standing and USEABLE after the inevitable Cascadia mega earthquake. It is being called a "lifeline route". It will be the first such bridge in Portland.

As far as structural engineering related costs I think Tilikum is also designed to remain functional after a major EQ, and for sure would be used as a lifeline as well. Maybe not technically a lifeline due to non structural reasons.

[sopdx]

Originally Posted by PhillyPDX

As far as structural engineering related costs I think Tilikum is also designed to remain functional after a major EQ, and for sure would be used as a lifeline as well. Maybe not technically a lifeline due to non structural reasons.

I think the Sellwood is also built to withstand major seismic events.

[eric cantona]

Originally Posted by sopdx

I think the Sellwood is also built to withstand major seismic events.

From the internets:

The connecting approaches for the Tilikum Crossing, particularly on the west side, were built to a lower "life safety" standard. This means they are not expected to be serviceable or functional immediately after a major seismic event. The western approach also crosses under vulnerable I-5 and I-405 viaducts, which are likely to be heavily damaged and block access to the bridge.

The Sellwood Bridge is built to modern seismic standards, designed to withstand a major earthquake without collapsing. While the bridge structure itself is highly resilient, the seismic performance of the entire route could be impacted by potential landslides at the approaches, which would need to be addressed after a major event to ensure the bridge remains fully operational.

The new Burnside Bridge, also known as the Earthquake Ready Burnside Bridge (EQRB) project, is designed to a high seismic standard to withstand a major Cascadia Subduction Zone earthquake. It is categorized as a Priority 1 emergency route, meaning it must be functional immediately following a major seismic event. The bridge is expected to be usable immediately after a major earthquake, including a magnitude 9.0 event from the Cascadia Subduction Zone, with damage that is repairable.

[urbanlife]

Originally Posted by eric cantona

From the internets:

The connecting approaches for the Tilikum Crossing, particularly on the west side, were built to a lower "life safety" standard. This means they are not expected to be serviceable or functional immediately after a major seismic event. The western approach also crosses under vulnerable I-5 and I-405 viaducts, which are likely to be heavily damaged and block access to the bridge.

The Sellwood Bridge is built to modern seismic standards, designed to withstand a major earthquake without collapsing. While the bridge structure itself is highly resilient, the seismic performance of the entire route could be impacted by potential landslides at the approaches, which would need to be addressed after a major event to ensure the bridge remains fully operational.

The new Burnside Bridge, also known as the Earthquake Ready Burnside Bridge (EQRB) project, is designed to a high seismic standard to withstand a major Cascadia Subduction Zone earthquake. It is categorized as a Priority 1 emergency route, meaning it must be functional immediately following a major seismic event. The bridge is expected to be usable immediately after a major earthquake, including a magnitude 9.0 event from the Cascadia Subduction Zone, with damage that is repairable.

That could mean a lot of dead people if the landslides come from the west of the bridge...and by dead people, I mean people who have been dead for a while

[eric cantona]

Originally Posted by urbanlife

That could mean a lot of dead people if the landslides come from the west of the bridge...and by dead people, I mean people who have been dead for a while

ew.

[maccoinnich]

Request for Response for the Demolition Review for the Historic Landmark Burnside Bridge, listed on the National Register of Historic Places.