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Big Dig Boston ceiling collapse 21

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Many of epoxybot's comments are irrelevant to the issue at hand. An antiquated capsule system wasn't used; a dual cartridge metering gun mixed the components immediately prior to inectiing into the holes. The epoxy was ASTM-rated for damp applications and hole temperatures as low as 49[sup] o[/sup]F. I haven't seen evidence that the epoxy itself failed, as would be the case if improperly mixed or insufficiently cured.
The direct problem was improper application, such as not cleaning the holes, not cleaning the bolts, not filling the holes, etc. Possibly, excessive moisture -- the reported dripping water was from a CYA source.
The indirect problem was that management & engineering assumed perfect installation by workers, even to the point that the number of bolts was halved in some areas to cut costs.
Followup lawsuits:

Massachusetts to file civil suit against 15 Big Dig contractors
By Elizabeth Mehren, Los Angeles Times, November 28, 2006
"BOSTON — Charging that sections of the Big Dig tunnel system here were so defective that "it was just a matter of time before a tragedy occurred," the state attorney general said Monday that he would sue 15 companies involved in the project.

Atty. Gen. Thomas F. Reilly said the civil lawsuit to be filed today in no way abrogated a criminal investigation against project manager Bechtel/Parsons Brinckerhoff and other contractors on the $14.6-billion network of highways and tunnels that run under Boston.

Reilly's civil suit stems from the July 10 death of a Boston woman when two-ton ceiling panels fell on the car in which she was a passenger. The family of 38-year-old Milena Del Valle has filed a separate wrongful death lawsuit against nine Big Dig construction companies and the Massachusetts Turnpike Authority.

The attorney general said Monday that the Big Dig contractors named in his lawsuit were negligent in using epoxy anchor bolts to secure the massive ceiling panels.

"If you were going to hang concrete panels that weigh about 2 tons apiece and you expect this system to be secure, you'd better get it right — or don't do it at all," Reilly said at a news conference.

After examining the damage and reviewing reams of documents, Reilly said, "It's clear to me that they didn't get it right. The consequences were great. A woman lost her life."

Andrew Paven, a spokesman for Bechtel/Parsons Brinckerhoff, said Monday that the firm would have no comment.

Reilly said a criminal investigation that could result in manslaughter charges remains ongoing. He said he felt compelled to file the civil suit because of a statute that could set a Nov. 29 deadline for civil action connected with certain parts of the Big Dig.

His suit does not specify monetary damages. But by alleging gross negligence — one of several charges — the attorney general's office could circumvent a $150-million cap on damages negotiated by Bechtel Parsons/Brinckerhoff as part of its construction management contract.
..."
 
I don't think we can say for sure what the problem is, so it may or may not be improper instalation. I have found epoxy in a an overhad application is very difficult. Further, it appeared that bolted fitxture supported a continuos tee. this tee was suppoted at 4 or 5 points by turnbucle hangers. It would be impossible with out significant testing to know how mucjh load was in each hanger. By the same token, it would be very easy to overload a connection. There are many questions yet to be answered before we can say what really happened.
 

Latest News on Epoxy

Boston Globe
Big Dig job may have used wrong epoxy
Total of bolts affected not clear; probers ask who knew
By Scott Allen and Sean P. Murphy, Globe Staff | May 3, 2007

Contractors apparently used the wrong adhesive to install at least some of the bolts in a Big Dig tunnel ceiling that partially collapsed last summer, project records show, prompting criminal investigators to focus on whether the mix-up was a significant factor in the accident that killed a Jamaica Plain woman.

Invoices from the 1999 ceiling construction job show that Modern Continental Construction Co. received and apparently used at least one case of a quick-drying epoxy to secure ceiling bolts to the tunnel roof rather than standard epoxy, which the ceiling designers had specified.

The distinction was crucial to the safety of the ceiling: The "fast-set" epoxy holds 25 percent less weight than standard epoxy and is not recommended for suspending heavy objects overhead.

It is unclear how widespread the use of fast-set epoxy was, since most sales records don't list the epoxy type, but state criminal investigators are looking seriously at the possibility that the weaker epoxy was used in the ceiling section that collapsed when 20 bolts popped out on the night of July 10, 2006, according to representatives of several firms under investigation.

The investigators also want to know why no one raised the possibility that the wrong epoxy had been used when ceiling bolts started coming loose during construction of the Interstate 90 connector tunnel.

"If [workers] used the wrong stuff, which appears to be the case, the issue is who knew about this or were they reckless about letting the project go forward with the wrong stuff?" said a consultant to one of the firms involved in the ceiling project, who asked not to be named so as not to anger prosecutors who are presenting their evidence in secret to a Suffolk County grand jury.

Paul F. Ware, the special prosecutor leading the state's criminal investigation, has sent investigators back into the tunnel over the last few days to collect more ceiling bolts for lab analysis, according to a letter from the Massachusetts Turnpike Authority, which manages the Big Dig tunnel system, to the companies involved in the ceiling project. The tests could help investigators determine the strength and type of epoxy that was used.

Use of fast-set epoxy in the ceiling is one in a series of missteps that may have contributed to the accident and, at the least, point out oversight lapses in the $14.6 billion Big Dig project.

The Globe has previously reported that, to save time, Big Dig managers and designers eliminated half the ceiling bolts called for in the original ceiling design and that construction workers made numerous mistakes during installation of the bolts that could have weakened them. The newspaper has also reported that ceiling bolts in the area of the collapse were safety-tested with a weight now regarded as too low, potentially allowing defective bolts to pass.

If the bolts were held in place by fast-set epoxy, the ceiling would have had little, if any, margin of safety left. Bolts secured with fast-set epoxy could safely carry 4,285 pounds each, rather than the 6,350 pounds the designers had planned on, based on their final report to Big Dig managers on the ceiling. Two independent engineers who have reviewed the ceiling's specifications for the Globe estimated that the ceiling's weight was close to 5,000 pounds per bolt, which is more than bolts secured with fast-set epoxy were designed to bear over the long term.

After the accident, the tunnel ceiling was permanently removed in the area of the accident, and elsewhere in the connector the ceiling was reinforced with additional bolts and brackets.

Construction of the ceiling was supervised by engineers at the joint venture of Bechtel and Parsons Brinckerhoff, but responsibility for using the right epoxy is difficult to pin down. The Braintree office of Gannett Fleming designed the ceiling to be secured with standard epoxy, but that require ment is not highlighted in project documents. Modern Continental built the ceiling, but workers have said they weren't told there was an important difference between the epoxies. Powers Fasteners of New York had a contract to supply the epoxy and bolts, but only through a small distribution company that bought the products wholesale and then delivered them to the job.

As a result, each company has said it bears no responsibility for use of the wrong epoxy. In fact, Powers Fasteners officials have told investigators that they aren't even certain that the epoxy in the accident area was their product, even though, during construction, company officials visited the tunnel and provided technical advice to workers on how to install the ceiling bolts properly. Powers' distributor, Newman, Renner, Colony of Plymouth, declined to comment.

The investigation into what epoxy was used has been hampered by both the imprecise sales records and the difficulty of chemically identifying the epoxy used in the area of the accident. The National Transportation Safety Board reported four months after the crash that it could not identify the epoxy taken from the failed bolts even after comparing it with samples of standard and fast-set epoxy. And the sales records that show what Newman, Renner, Colony delivered to Modern Continental distinguish between standard and fast-set epoxy in only one invoice.

State investigators in recent months have intensified their interest in Powers, sending company officials a fresh subpoena in March asking for documents concerning its role in the ceiling project. In addition, witnesses from other companies called before the grand jury hearing evidence in the case say they are being questioned closely about the type of epoxy used to hold up the ceiling.

"All the discussion outside the jury room is about the question of which epoxy was used and was it fast-set epoxy?" said an official for one of the companies under investigation who asked not to be named.

The focus on epoxy comes as Ware and his boss, Attorney General Martha Coakley, strive to meet a self-imposed deadline of June to decide whether to ask the grand jury to return indictments against anyone for criminal negligence in the accident. Legal analysts say that winning a conviction would require Coakley to prove that people or companies knew they were building a dangerous ceiling or they were so reckless that they missed obvious warning signs.

Before taking office in January, Coakley had raised doubts that the evidence was strong enough to prove criminal negligence, but, since Ware's arrival on March 1, some in her office say they have become more optimistic that there could be enough evidence for criminal indictments.

But fixing responsibility for the epoxy remains challenging, in part because the design documents produced by Gannett Fleming and Bechtel/Parsons Brinckerhoff say only in passing that contractors should use standard epoxy rather than fast-set for ceiling bolts. All of the safety calculations are based on bolts secured by standard epoxy, but the design specifications don't explicitly forbid fast-set, and the fact that fast-set can support less weight than standard epoxy is contained only in a footnote.

Adding to the confusion, although fast-set epoxy cartridges were clearly marked, the workers installing the ceiling may not have known there was a difference between fast-set and standard aside from drying time. Construction workers on the ceiling project have said they used Powers Fasteners epoxy and bolts, but they don't recall whether the label said fast-set.

Finally, the epoxy passed through many hands on its way to the tunnel. Sika Corp. manufactured the epoxy at a plant in Ohio, then shipped it to a warehouse in New Jersey in barrels marked with a prominent "FS" to denote fast-set epoxy, according to Sika officials. Powers then transported Sika's epoxy to its plant in New York where workers repackaged it into small cartridges, placing Powers's label on it. Then, Newman, Renner, Colony brought the cartridges and bolts to Modern Continental at the tunnel site.

Criminal investigators are focusing on a period in October 1999 when five ceiling bolts came loose shortly after the ceiling was hung from them, prompting Modern Continental officials to call in Powers Fasteners officials for advice. Over the next three months, officials from Powers, Modern and Bechtel/Parsons Brinckerhoff discussed ways to install bolts more securely, but there is no evidence anyone asked: Did workers use the right epoxy?

As one lawyer with direct knowledge of the investigation put it, "Was the right advice given by the experts?"
 
I love that "As a result, each company has said it bears no responsibility for use of the wrong epoxy." Huh? Who is at fault, the Easter Bunny? No, don't think the Easter Bunny was involved in this project, though with as much money as was spent and wasted, I wouldn't be surprised if Mr. Bunny was on the payroll. Sarcasm aside, who is the project manager for this tunnel?
Possible culprits:
Designer: The designer specified the right epoxy, how can he be at fault if they build it incorrectly? How much oversight does the designer really have? (ask the engineers who lost their licenses after the Hyatt walkway collapsed).

Epoxy maker: how is he supposed to know what load they put on the epoxy? It's only his job to tell them how to use it, not to figure out if it should be used at all.

Workers: the workers put in whatever epoxy was handed them. Nope, they look to be guilt free, unless you have some rogue workers running around to hardware stores, buying up whatever epoxy fit their fancies.

Program manager: The program manager is responsible for building as designed AND fixing any unforseen problems; I say they are completely at fault. That's why you get paid the big bucks, so take your medicine, I say.
 
I don't know, it appears to me that the epoxy company, Powers Fasteners may have culpability here.

1. If the standard material was approved and the fast set (the story stated that fast set was not recommended to suspend loads overhead) material was sent to the job to secure ceiling panels overhead.

2. There were problems during installation and the contractor had the epoxy company come to the jobsite to check on the installation.

3. It appears the epoxy firm had the knowledge on the material limitations but failed to tell the contractor.

So the questions are: Why was fast set sent in the first place (wasn't approved)? Why didn't the epoxy company notice this in at the jobsite? Why didn't they act if they knew? How could they know of the problem?
 
Maybe I don't understand the relationship the epoxy company has with the actual construction. I would think that the epoxy company is just responsible for sending whatever was ordered, and how it was used was not their place to say. The application looked right, the loads were wrong (that is, too high for that particular epoxy); since the epoxy company wasn't paid to do the stress analysis that determined the load, then how could they be responsible for incorrect use of their epoxy?
 
....or it could be that there were multiple uses on that project for overhead, and non-overhead, applications and the fast-set was sent for the non-overhead uses, but got mixed up by personnel in the field and used incorrectly in the overhead applications. Powers may not have ever known that they were using the fast-set.

This is all speculation of course - the investigation hopefully will find who did what, when, and who knew what and when.

 
The epoxie manufacturer (repackager)is possibly at risk here. Many times on large jobs (and even smaller jobs) manufacturers or repackagers like Powers tend to stretch the numbers to make their adhesive work in any and all situations to "get the business". I would imagine situations where the salesperson is on-site and says whatever is needed to make the adhesive on-hand "work" for whatever the application. Once it is in the hole and cured "nobody knows" what is in the hole. As it is the NTSB cannot figure out what adhesives are in any hole after they are cured. I find it hard to believe that the distributor on such a high-profile job sent whatever was on the shelf instead of the specified material. Key takeaway from this is to use manufacturers of adhesive, not repackagers. Simpson, Hilti, Sika, Red Head are all liable for bad product because they make it. Powers will pass liability on to Sika without second thought. KNOW WHAT YOU ARE SPECIFYING, CONTROL THE JOB!!
 
Hope this dispute over which epoxy was used doesn't obscure the real question, which is whether or not epoxy bolts should have been used in this application. I think the clear answer is NO!
 
It seems to me also that this misses the point. If the quick-fix could "safely" carry 4,285 lbs, but failed at 5,000 lbs, either their definition of "safely" is way different than mine or else there was still some serious problem.

With regards to whether the quick-set was supposed to be used in overhead, I would think that would have more to do with insurance, liability, and legalese than actual suitability. I know a lot of the chains, ropes, and cables sold have a "not for overhead lifting" warning label, sounds a lot like "don't blame us when you kill yourself."
 
Hokie66...
With proper engineering and installation, epoxy secured anchorages can be used successfully and can be 'proofed' for load capacity.

JStephen...
By safely carrying, 4285 pounds, the anchorages should have a safety factor of 3 to 4, typical for fasteners... This means that they can actually carry roughly 15000 lbs under ideal conditions, including installation... With proper installation they should be capable of supporting a 5000 lb load...

the kicker to the discussion is the fasteners have an incredible variability in installation, hence a safety factor of 3 to 4. The installation should have been more closely monitored and tested. I'm not aware of any testing during the installation. There are simple pull out devices that can be used to test any or all of them, if necessary. It is likely that field review was limited due to budgetary restraints and if I were the adhesive supplier, I'd be looking at field review, skilled field personnel (both contractor and consultant) and budgets. The epoxy material is sound and the failure appears to be one of attachment of the epoxy to the concrete... epoxies are adhesives and should be used as such.

The use of safely using innovative and economical materials is clearly the realm of the engineer and this includes proper checking the installation, in particular for innovative construction (I'm not sure that epoxy anchorage is innovative, though; it's fairly common). When proper testing and field review is factored into the cost, there may be more economical methods of fastening, but that's another scenario.

Dik
 
Dik,
Reading back through the postings, I see that you were always a supporter of epoxy, as I was always a naysayer. Guess my jobs won't use them and yours will. Simple as that. I completely understand your argument and disagree on the grounds of what my experience tells me is achievable in the field.

 
FYI...this should be good for the debate.

NTSB Advisory
National Transportation Safety Board
Washington, DC 20594
July 5, 2007

NTSB MEETS TO ADOPT FINAL REPORT ON CEILING COLLAPSE IN BOSTON'S BIG DIG TUNNEL


--------------------------------------------------------------------------------

Washington, DC -- The National Transportation Safety Board will hold a public Board meeting on Tuesday, July 10, 2007, at 9:30 a.m., in its Board Room and Conference Center, 429 L'Enfant Plaza, S.W., Washington, DC.

There is one item on the agenda:

On July 10, 2006, a passenger car was traveling eastbound in the Interstate 90 (I-90) connector tunnel in Boston, Massachusetts, en route to Logan International Airport. As the car approached the end of the I-90 connector tunnel, a section of the tunnel's suspended concrete ceiling became detached from the tunnel roof and fell onto the vehicle. Concrete panels from the ceiling crushed the right side of the vehicle roof as the car came to rest against the north wall of the tunnel. The passenger was fatally injured and the driver had minor injuries. A total of about 26 tons of concrete and associated suspension hardware fell onto the vehicle and the roadway.

Directions to the Board Room: Front door located on Lower 10th Street, directly below L'Enfant Plaza. From Metro, exit L'Enfant Plaza station at 9th and D streets escalator, walk through shopping mall, at CVS store take escalator down one level. Board Room will be to your left. A live and archived webcast of the proceedings will be available on the Board's website at Technical support details are available under "Board Meetings." To report any problems, please call (703) 993-3100 and ask for Webcast Technical Support.

A summary of the final report, which will include findings, probable cause and safety recommendations, will appear on the web site shortly after the conclusion of the meeting. The entire report will appear on the web site several weeks later.




Media Contact: Keith Holloway, (202)-314-6100
 
A cople of weeks ago the news carried a story that the repairs had been completed and the tunnel reopened. They were able to fix the problem for just over $50.000.000 of our dollars.
 
Most of the reports are out. It should be noted that this creep issue was specific to this type and brand of adhesive/epoxy. Not all adhesive/expoy anchors have creep issues. You will probably want to verify the anchors you are specifying do not have this creep issue. I work closely with adhesive anchors and had no idea this was an issue with this product. As I understand, the fast set version is the cheaper of the two and is most commonly sold even though the slow set version data is typically published.




 
I work closely with adhesive anchors and had no idea this was an issue with this product.
Click to expand...

PackerFan - you and me both!

(btw: Go Vikings)

 
Read 'Engineers of Dreams' by Duke University's CE dept head, Petrosky.

In one of the last chapters he describes the generation gap effect in bridge engineering. In 30 yr cycles, later generations choose to ignore the wisdom and experience of their mentors. This explained successive bridge disasters:
- Tay rail bridge, truss, ~1880;
- Quebec rail bridge, cantilever, ~1910;
- Tacoma hwy bridge, suspension, 1940;
- Various box girder bridges, 1970;
- We are overdue for a stayed bridge disaster.
 
More than enough blame to go around.
More legal fees.
More grist for the wheels of justice.

Ultimately, some jury or a federal judge will apportion damages according to who has the deepest pockets.
 
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