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Here's one for all you pocket engineer's.  How do 40 ton bridge beams bend on their own after being installed? Do you think heat straightening would work?http://news.nationalpost.com/2015/03...dge-expansion/Last edited by Welder Dave; 03-17-2015 at 07:49 PM.
Reply:I think I know those guys who did the rigging. I worked with them before, they could break a cannon ball! Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:They're trying to figure what caused it. My off the wall guess would be the beams were held straight when welded and had a lot of built up stress or the welding of the stiffener plates wasn't done properly.
Reply:The pigeons did it.www.georgesplasmacuttershop.comPlasma Cutter and Welder Sales and Repairs--Ebay storeTec.Mo. Dealer Consumables for the PT and IPT torch's
Reply:It will be interesting to hear what did happen.When all the I-90 work was going on across Mercer Island to Eastgate. A crew placing the prestressed concrete I-beams didn't secure them properly. Wind picked up over night, and blew the beams over. Prestressed concrete beams are really strong standing up right, not so much on there sides.Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Ouch! Looks like a Friday afternoon "critical lift". When in doubt wait until Wednesday, nothing good happens on a Monday or Friday. It seems the rigger and signal men need new careers. I bet the crane operators will get all the blame, mostly the crane down below. He must have thought the thumbs up from the signal man meant good jobThermal arc 211iCk flex-loc 150 & 130Clamps, saws & grindersHarbor freight 80 amp inverter
Reply:since three warped the same way, I'm thinking the earth shifted or something equivalent that caused the "beams" to bend and buckle in the same direction. Crazy regardless.
Reply:I wonder what the time frame on the movement was......cause I would be like freaking out man.
Reply:I tried to tell that guy not to weld his section with his 110 volt MIG.Hobart Beta-Mig 2511972 Miller AEAD-200LEMiller 250 TwinNorthern Ind. Hybrid 200Longevity Stick 140Longevity Migweld 200SThermal Arc Pak 3XR
Reply:Guess the solar storm was more than they expected. MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Being up in Canada  I'd say the polar magnetism  is to blame or like mechanic 416 said the pigeons  did it.
Reply:In all seriousness, is boom deflection real?Thermal arc 211iCk flex-loc 150 & 130Clamps, saws & grindersHarbor freight 80 amp inverter
Reply:They had 6 in place and were about to place the seventh beam when they noticed 4 of them were buckling. The road could be closed for up to a year and it's a busy road so lots of headaches in rush hour. Will be interesting to see if they can figure out what caused the massive beams to twist like that.
Reply:Maybe cold temp in the morning, ends were welded or fastened, then warmer temps came later in the day?Not the same, but I've seen the electrician's PVC on a 200' barn ceiling, which was installed at 20 degrees, go completely ape when the barn was warmed to 70 degrees an hour later. It can grow two inches with that kind of length. It couldn't expand because of the light fixtures every 12 feet. It was trapped.KevCentury 100 | Miller 250 | ESAB 353Who is Dan Well? Everyone always says to me, "You know Dan Well!"
Reply:Not too much temperature change. Probably within 5 or 6 deg's on either side of freezing.
Reply:Meh...Weld in some cross bracing and carry on...        Miller 211Hypertherm PM 451961 Lincoln Idealarc 250HTP 221  True Wisdom only comes from Pain.
Reply:The bridge just has a dogleg now. Don't see what the big deal is.
Reply:Probably a million dollar plus mistake.
Reply:Welder-DaveLet the video play to the end - it remains as a still-shot - and is the best top-view.This is what I see in the pics . . .Viewing left/to/right - beams #6 to #7 [rt. side] - reference: the diagonal cross-ties on plane, and just above the bottom flanges.  They are clearly absent between beams #4 to #6 in the 'hard-hat' pic - all you see is sun-light ground.   I speculate 'out-board' beams #1 to #2 have the same bottom diagonal bracing.This bracing effectively boxes 'the parallel', and is intended to serve as a horizontal'strong-back' to couple the 'sisters'.From beams #1 to #3 - there is a full compliment of horizontal cross-ties/full span. Compare the over-head [video] with the 'hard-hat' pic.  In the over-head view - the center section cross-ties are obviously sparse/absent.If you closely examine still-shot #1 you can see the buckled cross-ties - 'both of them' [3 pairs] - between beams #3 to #6.  Each pair is buckled-up, and consistant with angle-iron compression failure.'Fabricated beam hinging' under its' 'own-load' is nothing new.  I don't expect the findings to be an: Engineering flaw - but field 'Lackadaisia'.Someone decided that: 2/ties x 3 - was just as good as - 4/ties x 4.  'They never got to 4' - courtesy of: 'accumulative transverse-loading'.The symmetry of the omited cross-ties produced the 'hinging' wave-form. The 'pairs' of angle-iron cross-ties were weaker in compression than in tension.  This is why the beams collapsed/folded left. They had all of the pieces - they just didn't use them.If you follow the recipe you will get a cake - if you don't - you get Humpty Dumpty.Opus.Last edited by OPUS FERRO; 03-18-2015 at 03:37 AM.Reason: Mech/ic416 . . . Its been a long time since I've blamed squab.
Reply:Originally Posted by OPUS FERROCompare the over-head [video] with the 'hard-hat' pic.  In the over-head view - the center section cross-ties are obviously sparse/absent.
Reply:Originally Posted by DSW"Hurry up! Quit messing with that junk. We can put the rest of those cross braces in later.  3 is fine for now. We need to get these beams set and get those cranes out of here. We're running behind and need to pick up the pace! ..."
Reply:Originally Posted by DSWYeah probably one of those "Hurry up! Quit messing with that junk. We can put the rest of those cross braces in later.  3 is fine for now. We need to get these beams set and get those cranes out of here. We're running behind and need to pick up the pace! ..."
Reply:Those are heavy beams to just bend like that.
Reply:isn't that why they put steering wheels in cars and trucksi.u.o.e. # 15queens, ny and sunny fla
Reply:I did a little reading today on bridge beams and remembered that they had to delay the placing of the beams because of wind. The wind didn't cause the bending but I now think they may have wanted to make up for the delay by trying to place all the beams instead of individually bracing them as soon as they were installed.Too much unsupported overhang ,wind and not following erection plan to fill in as set. That will be the findings. Hurry up work hope no one was hurt.
Reply:Why is the center section of the one beam darker than the others? It has the look of being heated and cooled.12v battery, jumper cables, and a 6013.I only have a facebook page. https://www.facebook.com/pages/VPT/244788508917829
Reply:Cranes are spendy, local contractor here had a whole stick framed building come down around them when they pushed ahead too fast and set all the trusses without completing their bracing as they went. A million dollar building turned into toothpicks in 10 minutes because they didn't want to pay for another few hours of crane time. Lateral bracing was left out and the walls weren't properly braced and sheathed, trusses started to tip and the shift caused the walls to hinge. A couple hours of of sheathing walls instead of setting trusses would have kept the building up, a few more of putting in lateral bracing would have kept the whole thing from happening. At most they would have lost a day or two of progress on the roof, instead they saw dollars burning in crane time and it cost them all their progress and the building.Looks like the same thing happened here, instead of loosing a few days to do it right, they tried to take a shortcut and it cost them the bridge and a year of time.
Reply:Now the contractor is footing the bill to bring in a huge 1200 tonne crane that can pick up the whole assembly. They think the beams might be spring back straight. The crane is too big to move in one piece and has to be assembled on site. Apparently there are only 7 of these cranes in N. America.
Reply:Are you kidding they are scrap , take em down and refabricate. Hurry up erection goes wrong!
Reply:Here's an interesting before/after picture (use the slider).  Happened in the span of about 15 minutes and not much in the rigging appears to have changed.http://edmonton.ctvnews.ca/groat-roa...ions-1.2282110"USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:This was one of those where the clock was ticking. It could have failed later when some guys were out there adding the missing cross bracing."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:It may not be the fault of the erector but girder stability should have been checked. The design appears to be very light to USA standards and could be a problem.Thin narrow flanges deep webs and light crossframes may not be stable untill the pans and deck poured. We had a similar problem on the Isod Arena in NJ our erection engineer told us the roof truses would not support their weight untill the roof deck was installed we told the authority and the said we were wrong. Built a truss on the ground picked it with a 4100 /9299/ 7700 Lima and it started to bend and set it back on the ground. A 3.5 MILLION change order for bracing we put it up.
Reply:Quote Originally Posted by DSW  View PostYeah probably one of those "Hurry up! Quit messing with that junk. We can put the rest of those cross braces in later. 3 is fine for now. We need to get these beams set and get those cranes out of here. We're running behind and need to pick up the pace! ..."Sounds about rightIsn't that always the story?We're running behind!!!
Reply:It wasn't the pigeons - it was the pigeon poop.