The Wickiup Junction Overpass project is just north of La Pine, Oregon.
First this happened ??
August 2016 ??A construction accident at the Wickiup Junction railroad overpass project north of La Pine on Monday caused no injuries but sent two large, heavy concrete beams falling, one blocking the train tracks below for five hours, officials said.?
And then this ??
9/26/2017 Newspaper article: http://www.pamplinmedia.com/pt/9-news/373473-258198-engineers-tear-down-12-million-highway-97-bridge
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OUCH. I don't know what else to say-
OH, BOY!! Somebody needs spanked and spanked hard.
That is a really tragic outcome. While I'm sure everyone involved was competent in their position, I see a more-or-less failure of the organizational system.
When I was with the highway department here in Oklahoma I saw several large projects with a design process fragmented between departments that rarely talked with each other. Sometimes the less-than-adequate outcome was almost predictable. One was a highway overpass with a railroad underneath. The project had been shelved for several years due to funding before a construction contract was eventually let. The contractor was slip-forming the bridge deck when someone realized the BN&SF had rebuilt their line a few years earlier (after the initial design survey) and raised their grade a number of feet. Oops.
I've seen several other "aw shoot" moments that almost ground to a halt some big stuff...but nothing in the magnitude of a 12m buck viaduct that was winding up in the trash can.
They could probably put those pre-stressed concrete beams on eBay and recoup a little of the money. 😉
paden cash, post: 448566, member: 20 wrote: That is a really tragic outcome.
Indeed Paden. I was first told that this diatomaceous soil differs from others in the area in that it isn't as decayed. Instead of being smooshed up fragments of diatom skeletons, these supposedly are not as decayed and fractured and therefore are like a pit of pingpong balls on a microscopic level. I'm not a soil tech so I can't vouch for this explanation. This bridge was going to fix a bad situation on a major highway.
We staked and they built a 10ac site for dumping coal dust.
They dumped two truck loads of dust and it rained.
Before it was time to dump again the sun came out and the dumped coal dust hardened.
They did not dump anymore coal dust and instead it became an additive for concrete and substitute for other similar filler products.
When I saw the first of this film, I thought of the overpass that was built from DOT info and new rails built from RR info and neither had ever been compared as to actual msl elevation.
Well it was a couple feet different and trains could not fit under the overpass.
There are a few surveyors that may read this and start the feud all over again because it is not a popular topic locally.
Soil studies are costly and it takes some real insight into checking over 200ft deep and some real knowledge of the local land to know to do that.
I've been on jobs where hard driven piles disappeared into the earth by the next day.
Concrete walls and slabs started to sink as soon as they were poured and/or was not noticeable until they started to connect the steel.
Bottom line is that some days nothing works.
Mike Berry, post: 448573, member: 123 wrote: Indeed Paden. I was first told that this diatomaceous soil differs from others in the area in that it isn't as decayed. Instead of being smooshed up fragments of diatom skeletons, these supposedly are not as decayed and fractured and therefore are like a pit of pingpong balls on a microscopic level. I'm not a soil tech so I can't vouch for this explanation. This bridge was going to fix a bad situation on a major highway.
There's a major interstate junction bridge over a river not far from here. During construction the contractor hit quicksand while attempting to drill and place sheet pilings to pour a pier base. There was simply nothing underneath that would bear weight. The state paid to have pilings driven to a depth of about 120' where the contractor said "can't go any deeper". There was still really nothing down there but ook...
They poured the pier and continued on. The engineer's recommendation was to monitor the pier for movement. And we (the survey division) did; every month there for a while. Surprisingly to my knowledge it settled a bit and then stopped. By the time they had the beams hung and the deck poured everything was ok...I guess. That was almost twenty years ago and I think about it every time I drive over that span.
ODOT has got to be still stinging from the Pioneer Mountain project. Soil/slope stability problems there resulted in the the project going triple original budget and several years past due. Several unstable bridge bents had to be blown up.
How do you even consider designing a substructure without borings at each bent? I just spent $3k for two 60ft deep borings on a bridge that will cost about $180k PRIOR to ROW acquisition. I understand ODOT would have to go much deeper, but heck, they're investing much more money at the site as well.
Steve
I always feel that they ask for too many borings around here, now I see why they are so important.
Not quite the same problem, but a few years ago an overpass was built on the PA Turnpike to replace an older one (to widen the turnpike), but it was built too low. You would think things like that would be checked and double checked.
FL/GA PLS., post: 448614, member: 379 wrote: Guess who's tax dollars are going to pay for this faux pas?
Some of it will be yours, because I'm sure there was federal money in these projects.
How could you begin construction on a project like this without soil borings and analysis BEFORE you started construction???
Chuck S, post: 448629, member: 698 wrote: How could you begin construction on a project like this without soil borings and analysis BEFORE you started construction???
This. I mean we have to do soil borings on 600 s.f. stormwater facilities to make sure they are going to get the correct infiltration rate
James Fleming, post: 448631, member: 136 wrote: This. I mean we have to do soil borings on 600 s.f. stormwater facilities to make sure they are going to get the correct infiltration rate
In the story linked above, ODOT says they did their routine boring to 125', turns out that wasn't sufficient...
I've monitored large fills as soon as the major grade was made just for this reason. I can understand the error by the soils engineer in the initial analysis but if monitoring subsidence would have begun at the end of the fill placement many dollars of construction costs could of been saved. Oh yeah I forgot, the surveyor role has been largely written out of construction in Oregon with the invent of machine control. Jp
FrozenNorth, post: 448642, member: 10219 wrote: In the story linked above, ODOT says they did their routine boring to 125', turns out that wasn't sufficient...
No, it says they went to 280"...
Jim in AZ, post: 448673, member: 249 wrote: No, it says they went to 280"...
My reading of this was that the 280' borings weren't until later in the project:
"The advanced subsurface tests were conducted after engineers noticed two earthen embankments constructed for the overpass were settling faster than expected."
Seems to me if they really wanted that bridge there, some sort of load bearing pilings, or maybe a very large spread footing would be able to handle the load. Look at the new tapered piles on teh Bay Bridge in San-Fran as an example.
In any case, I may take the bridge over the tracks out, everything else stays as a pre-load to see if it eventually stops subsiding.
Most geological studies are based upon limited field investigation as well as reports of record.
I don't think this ancient lake bed was known or described and the initial test borings probably went to a reasonable depth.
I would bet there are many people placing blame that have no idea the effort that went into the design of that overpass.
It doesn't sound like it is just the structure settling - the approach fill is sinking too.
