can we guess that UP is holding its breath that the Brazos will not flood and cause more damage to the bridge with this latest low pressure rains ?
I haven't been able to make a trip out to see the bridge yet, but the reports I've heard are that the new piers UP built (to replace the failed pier) have started to sink as well.
Apparently UP is now bringing back cranes and other equipment to the bridge site to prepare to work on the second round of repairs, but in the meantime they are still running some freight trains over the bridge at a 10 mph speed restriction (So I assume the sinking isn't too bad, yet).
However, both Sunset Limited #1 & #2 have returned to their detour over the BNSF via Alvin to get to Houston and a number of freight trains are detouring as well. Also, today the Ringling, Barnum, & Bailey circus train came through and used the same BNSF detour to avoid the bridge.
-Chris
"Bents" are inherently pilings, aren't they? I've never seen the term used to refer to anything else.
Still unable to confirm but seems that another support probably pilings and not pier is settling.
Uncnfirmed report that bridge has been closed due to additional settling of bents. 2 weeks to fix ?
EDIT/// Underlined may be incorrect see next post.
Looks like the bridge is back in service, according to the Yahoo group.
Yes ... Thank you .. Nice Modeling Job!!
Can you see anything in this thread?
http://www.trainboard.com/highball/index.php?threads/rebuilding-the-brazos-river-bridge.95014/
Pulling dirt out of pipes driven for new piers. The pipes will then be filled with concrete.
Clam shell device is lowered by crane down the inside of the pipe to dig out the dirt/mud.
They stabilized the approach spans then installed a box beam from the approach span to the stable pier. That allowed them to support the bridge from the box beam and they can remove or repair the damaged pier as required, since it no longer supports anything. When the pier is repaired, they lower the steel truss down on the new pier, remove the box beam, replace the span between the steel bridge and the concrete approach , replace the rail and are back in business.
Dave H. Painted side goes up. My website : wnbranch.com
This is just a WAG and if more pictures of the work becomes available will alter post accordingly.
It appears that there "may" be a beam of some kind that is extending over bents to the bridge pier. Could it be that this beam will allow the truss to be jacked up and a new pier built to support the truss section ? The only problem would be can the present bents & piles support all the weight of that beam ? Maybe a beam is long enough to place no load on the bents.
OvermodAn alternative would be to build the 'replacement' bridge gantleted, so that only some relatively simple operating restrictions, made particularly reliable with PtC, would be required to coordinate double-track operation across it with only minimum speed or braking restrictions and no points (and simple frogs).
Adding a second track up to a gantleted bridge would certainly require UP to widen their ROW in beautiful downtown Richmond; I have no idea if the local gov't and residents are amenable, but I don't see Beverly Hills real estate prices here.
BTW here are some recent pics taken of the bridge repair work.
Links to my Google Maps ---> Sunset Route overview, SoCal metro, Yuma sub, Gila sub, SR east of Tucson, BNSF Northern Transcon and Southern Transcon *** Why you should support Ukraine! ***
blue streak 1 ... If UP can update their engineering for the bridge replacement either a single track or double track bridge if may be much more economical to at least build new piers and piling bents now. Thaat way UP will not need to bring in equipment when the bridge is double tracked or a whole new bridge built. UP probably cannot get truss or prestressed bridge members built in a timely manner but who knows ? Any idea of what the present bridge's Cooper rating is? Is it possible that even a repair will reduce its rating? Of course a lot will depend if any Corps of Engineers review is needed. That work to build the piers and bents could save a lot of future funds?
I have to wonder a small detail further:
If restoring 'bents' does the exact structure have to be replaced in detail, or can a somewhat stronger replacement be put in with the same 'footprint' in the rivercourse?
Very common in modern precast concrete construction is a bridge structure that is wider, but statically balanced, over central piers. It occurs to me that this bridge could be redesigned with a much reinforced pier to which a cantilever top and then two tracks could be applied 'entirely above the river' (and perhaps thereby reducing or even avoiding steps of a permitting process, environmental review, etc.)
An alternative would be to build the 'replacement' bridge gantleted, so that only some relatively simple operating restrictions, made particularly reliable with PtC, would be required to coordinate double-track operation across it with only minimum speed or braking restrictions and no points (and simple frogs).
This is pure speculation but :::
UP has had to spend a lot of funds to access this washout. Access roads on both sides of track,, maybe temporary easements, access peermits if government land is involved, maybe waterway restrictions (?), rock for access roads, transportation costs to bring in heavy machinery and temporary materials.
Then UP will have all the cleanup and restoration work for any access roads.
This route has been noted on the Sunset double tracking thread to become 2 MT..
If UP can update their engineering for the bridge replacement either a single track or double track bridge if may be much more economical to at least build new piers and piling bents now. Thaat way UP will not need to bring in equipment when the bridge is double tracked or a whole new bridge built. UP probably cannot get truss or prestressed bridge members built in a timely manner but who knows ? Any idea of what the present bridge's cooper rating is ? Is it possible that even a repair will reduce its rating ?
Of course a lot will depend if any corp of enginers review is needed. That work to build the piers and bents could save a lot of future funds ?
The connection between BNSF Galveston Sub and UP Glidden Sub at Rosenberg is limited. Trains can only go from westbound UP Glidden to northbound BNSF Galveston or southbound BNSF to eastbound UP. So the Sunset Limited eastbound on UP Glidden has to cross the former Tower 17 interlocking, stop and wait a few minutes for signals to clear, back up onto BNSF Galveston, stop and wait a few minutes for signals to clear, then cross Tower 17 interlocking southbound on BNSF Galveston and head for Alvin. The westbound Sunset Limited has to pass Tower 17 northbound on BNSF, back onto UP, then proceed west through Tower 17 towards San Antonio. It's even more fun to watch when 75-100 car UP and KCS unit trains and manifests have to do the same moves.
mudchickenThe H-Pile approach bents, I suspect, are fine and the old concrete and stone abutments on reed matts are finished.
The soil around the bents was scoured. So no skin friction or bracing on thin columns.
About 5 acres of river bank was scoured 30 ft deep.
mudchickenThe diver, who looked at scour probably did the job totally by feel/touch (scary in that turbid water,
Sonar.
Really tricky, if you drive pile you disturb the comromised pier. The actual solution will be very inventive. This should end up being an award winning reconstruction.
The reroute of #1 and #2 through Alvin is the former Texas Chief route from Santa Fe operations. Why did it take Amtrak so long to find it, or were their further complications?
great pictures !!! thanks !
Here's a shot I took of a train going over the bridge from a couple months ago when the river was at a more normal height (now imagine it about 3 ft from the deck of the bridge!).
I took the shot from the east bank of the river; the pier that sank is out of frame to right about 100 ft or so (it's the opposite of the pier to the far left in the image). As you can see the pier is not normally in the water, and the ground beneath - which is a soft clay - likely just washed away in the flooding (which peaked at a flow rate of about 100,000 ft3/s, a tad bit above the normal 7,000 ft3/s).
MikeF90 It will be interesting to see how this plays out. Before the recent downturn UP was extending the second MT west from Houston to (possibly Tower 17 in) Rosenberg. This would require a new bridge; looks like it might need to be higher than the existing one.
It will be interesting to see how this plays out. Before the recent downturn UP was extending the second MT west from Houston to (possibly Tower 17 in) Rosenberg. This would require a new bridge; looks like it might need to be higher than the existing one.
As an interesting note, about a week before the bridge at the Brazos was taken out of service UP had just put into service a new 10-mile stretch of 2MT between Missouri City (on Houston's southwest side) and Sugar Land, about 5 miles east of the Brazos River bridge.
Other than extending that another two miles to Harlem (the next siding two miles to the west of Sugar Land), I doubt UP is going to add any more 2MT to the Glidden Subdivision anytime soon due to the ROW restrictions in Richmond and the Brazos River bridge.
Also, in regards to the Sunset Limited, today it seems Amtrak finally figured out a reroute plan to get around the bridge. Yesterday morning Train #2 (eastbound) used the BNSF Galveston & Mykawa Subdivisions to get to Houston, leaving the UP at Rosenberg (just west of Richmond) and taking the BNSF southeast to Alvin (25 miles south of Houston), where the train then shot north up to Houston. Once in Houston, the train returned to its original routing by shoving backwards to the Houston Amtrak Station from Tower 26.
I would assume #1 (westbound) will take the same routing tomorrow and that both trains will continue to use the BNSF until UP's bridge is repaired.
Reminds me a lot of the summer of 1993. Had a similar occurance on one of our bridges in MO. Water undermined the pier in an approach span and dropped the pier. Had to drive new pile around it to bring the spans back up.
Something similar will probably be done here. Looks like a good case study to update AREMA's Bridge Inspection class segment on Scour. This is a classic "Fix the River" scenario. In the video, see how much of the bank has been cut away because the river is moving towards that bank. Only effective way to respond to that is to place control structures on the outside of the bend in the river to push it back to where it came from.
mudchickenBridge contractor and Uncle Pete's bridge engineers in Omaha have probably put in some long nights on this and have dug up all the history they can on the thing.
The red machine is a lattice boom crane,probably a Manitowoc from the color. The white machine is a hydraulic crane, necessary to assemble the bigger machine. Any dedicated pile drivers are likely in museums. Either of those machines can drive piles with a pile lead and hammer.
Bridge contractor and Uncle Pete's bridge engineers in Omaha have probably put in some long nights on this and have dug up all the history they can on the thing. The local geology is going to be the driving force on what happens here. The H-Pile approach bents, I suspect, are fine and the old concrete and stone abutments on reed matts are finished. The diver, who looked at scour probably did the job totally by feel/touch (scary in that turbid water, if it was even safe to enter)...If there is zero piling in the old concrete bent, expect helper pile to be diven to support the two spans on either side of the failed bent supports, support the two structures and then put the track back into service. Then UP will look at its options, including the demo of the old structure and driving a new pile bent. No two bridge solutions are ever the same. A big part of the future is the status, clearances and load carrying capability of the existing steel truss for future 286K-315K loading. Some value engineering exercises are in order. (PDN?)
Wonder if this one will be a future AREMA presentation/discussion?
blue streak 1 Video of night time work. Look closely a pile driver and very large crane. Maybe crane will pick up end of bridge as pile driver installs new piles for bridge bents ? https://swrails.com/2016/06/10/brazos-river-bridge-repairs-june-9/
Video of night time work. Look closely a pile driver and very large crane. Maybe crane will pick up end of bridge as pile driver installs new piles for bridge bents ?
https://swrails.com/2016/06/10/brazos-river-bridge-repairs-june-9/
Looks like the flooding 'floated' the approach bents above the level of the bridge proper.
Never too old to have a happy childhood!
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