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The
National Construction Safety Team Advisory Committee
National
Institute of Standards and Technology
MINUTES
OF AUGUST 26-27, 2003, MEETING - Gaithersburg, Maryland
The
slides from the presentations are embedded as links to
PDF files
within this document and, thus, are summarized in these minutes.
Each presentation was followed by a discussion period. “Q” indicates
a question, “A” the corresponding answer, and “C” a
comment. All questions and comments, unless otherwise noted,
were made by Advisory Committee members. All answers unless
otherwise noted, were by NIST personnel.
August 26, 2003
Opening
Remarks
Dr. Arden L. Bement, Jr., Director, National Institute
of Standards and Technology
Dr. Arden Bement opened the National Construction Safety Team
(NCST) Advisory Committee meeting at 10:00 a.m. with a welcome
to the Committee members. He stated that he will be preparing
a set of tough questions that he will pose to the Advisory
Committee for their consideration and discussion at their next
meeting. The questions will be made public. He also asked the
Advisory Committee members for their input on questions that
should be posed to the Committee.
Mr. Paul M. Fitzgerald, Committee Chair
Mr. Paul Fitzgerald asked that recommendations or questions
for NIST be highlighted so that they could be captured in the
minutes of the meeting and reminded the Committee members that
their ability to influence the World Trade Center (WTC) investigation
was really only over the next few months. He also reminded
the Committee that questions or recommendations could be submitted
at any time.
Mr. Fitzgerald also noted that the draft agenda for future
meetings would be circulated to the Advisory Committee 5 to
6 weeks before the meeting. The Committee members will have
5 to 10 days to review and comment on the draft agenda. Advisory
Committee members should give suggested agenda items to Mr.
Fitzgerald or Mr. Cauffman as soon as possible.
The Advisory Committee
members discussed the possibility of having a verbatim transcript
of future Committee meetings.
It was decided that the objective of the minutes of the Advisory
Committee’s meetings is to summarize the discussions
and to capture the key questions and recommendations of the
Committee. Also, a transcript may be too voluminous. (Following
the receipt of public comments later in the day, this issue
was discussed further on the second day of the meeting.)
NCST Overview and Discussion
Dr. Jack E. Snell, Director, Building and Fire Research Laboratory
Dr. Jack Snell briefly
discussed the NCST Act and the role of the Committee. He
stated that on September 11, 2001, an
enemy of the United States of America hijacked and drove airplanes
into three buildings—the two World Trade Center towers
and the Pentagon. Incredibly, the buildings did not collapse
instantly but remained standing for some time—allowing
most of the occupants to escape and luring first responders
inside to facilitate rescue and attempt to bring the raging
fires under control.
Dr. Snell said that we know what happened, we even know who
did it. So why an investigation, and why a National Construction
Safety Team Act? The answers to these questions are important
and set the context for the Advisory Committee and their role.
1. NIST is doing the investigation to find out how the building
performed to assure the public that every practical means is
being taken to derive the appropriate lessons for practice,
standards, and codes.
2. The Congress enacted the NCST Act to ensure that means
were in place so that in the future such investigations would
be launched in a timely manner, that critical evidence would
be preserved, and that those responsible for conducting the
investigations had the resources and authorities necessary
to do their job. They also charged NIST with the responsibility
to see to it that appropriate steps are taken to act on the
findings and recommendations of the investigation teams.
The Advisory Committee’s
job, as Paul and Arden so eloquently have stated, is to advise
the director on how NIST does these
things, so that the results are optimal. NIST much prefers
the quarterback get the best possible signals during, rather
than after, the game.
In this context, the Advisory Committee too now has a full
plate. Dr. Snell briefly reviewed the agenda and tasks:
- Become
a well-functioning team
- Advise
on the procedures for implementing the act, including the
criteria for launching teams
- Flesh
out an outline and approach for providing advice to the
director on the two investigations now under way
- Develop
an outline and approach for the Committee’s annual
report to Congress—keeping in mind the requirements
of the act as outlined earlier.
What is the end point of what NIST does under NCST? Deriving
full public benefit from building failures in the form of thorough,
objective, factual investigations, and timely and appropriate
follow-on actions. Full public benefit typically will result
from beneficial, timely, and cost-effective change to practice,
standards, and codes.
Thus the normal sequence of activities for a NIST-led NCST
investigation would be:
- Conduct
the investigation
- Report
findings and recommendations
- Conduct
research and other activities to enable and ensure implementation
of the findings and recommendations
- Keep
track of the consequences of those activities
Dr. Snell then presented
a briefing on the Research and Development (R&D) Program
and the Dissemination and Technical Assistance Program (DTAP).
PRESENTATION (pdf file)
The WTC investigation is already in full sway. Dr. Snell indicated
that in this highly unusual case, it is obvious that certain
efforts be initiated immediately; there is no sense waiting
until the ink is dry on the WTC investigation report to begin
to prepare for implementation of what will certainly be included
among the major findings and recommendations. He briefly reviewed
two important elements of the WTC response.
Investigations and the NCST provide a practical means to minimize
the likelihood of future consequences by providing a mechanism
for timely investigations and preservation of evidence. The
endpoint of the NCST Act is the full public benefit of rapid
implementation of knowledge gained from investigations.
The International Code Council (ICC) and National Fire Protection
Association (NFPA) have schedules for proposing changes to
model building codes. Both codes are revised on a 3-year cycle.
The deadlines for proposing changes to 2006 editions of the
model codes are October 17, 2003, for NFPA and October 2004
for ICC. The deadlines for proposing changes to the 2009 editions
of the model codes is October 2006 for NFPA and October 2007
for ICC. A change in practice can happen quickly. However,
changes in codes and standards can take years. For example,
NIST is already working with industry to begin developing the
technical basis for revisions to elevator standards for their
use in fire emergencies.
Q: I understand wanting to be expedient in recommending changes,
yet the code schedules are a long way off. Have you looked
at other mechanisms to get code changes implemented?
A: NIST has been talking to the principal groups involved to
develop a strategy for moving forward with recommendations.
In the next few weeks, NIST will contract with the National
Institute for Building Sciences (NIBS) to identify stakeholders
to develop a strategy to implement recommendations. We will
begin this work in the next few weeks.
Q: What was the response of the code organizations?
A: The code organizations are very supportive and look forward
to working with NIST on all of these steps.
Back to
agenda Federal Advisory Committee Act (FACA) and Criteria for Closed
Session
Mr. Michael R. Rubin, Counsel for the National Institute of
Standards and Technology
Mr. Michael Rubin addressed procedural matters related to
the functioning of the Advisory Committee, interaction with
NIST and the public and addressed the criteria that must be
met in order to hold a closed session of the Advisory Committee.
The Advisory Committee does not have the authority to decide
on topics to be covered in closed session. Rather, that decision
rests with officials at the Department of Commerce (DOC). Based
upon a written request from NIST, the General Counsel and the
Assistant Secretary for Administration at DOC must determine
in writing whether any closed sessions of the Advisory Committee
are permissible under the Federal Advisory Committee Act (FACA).
The general rule under FACA is that all advisory committee
meetings must be open to the public, and must be noticed in
the Federal Register at least 15 days prior to the meeting.
All meetings of the Advisory Committee must be held in a physical
site to allow the public to attend. It is possible for closed
meetings to be virtual meetings, but they would have to be
approved and would require advance notice in the Federal Register.
The criteria for closing Federal Advisory Committee meetings
are established in the FACA at 5 U.S.C 552b(c). There are 10
different criteria under which a Federal Advisory Committee
meeting can be closed. NIST anticipates that there may be instances
where meetings are closed in accordance with 5 U.S.C. 552b(c)
(4), (5), (9)(B), or (10) to allow the Committee to discuss
and advise the NIST Director on topics that meet these criteria.
NIST has received a favorable determination from DOC that permits
it to close portions of meetings that meet those criteria:
- (4) Disclose
trade secrets and commercial or financial information obtained
from a person and privileged or confidential
- (5)
Involve accusing any person of a crime, or formally censuring
any person
- (9)
Disclose information the premature disclosure of which
would (B) in the case of any agency, be likely to
significantly frustrate implementation of a proposed agency action,
except that subparagraph (B) shall not apply in any instance where
the agency has already disclosed to the public the
content or nature of its proposed action, or where the agency
is required by law to make such disclosure on its own initiative prior
to taking final agency action on such proposal
- (10)
specifically concern the agency’s issuance of a
subpoena, or the agency’s participation in
a civil action or proceeding, an action in a foreign
court or
international tribunal, or an arbitration, or the
initiation, conduct,
or
disposition by the agency of a particular case of
formal agency adjudication pursuant to the procedures
in section
554 of this
title or otherwise involving a determination on the
record after opportunity for a hearing.
NIST can foresee the possibility that it might seek authority
under 5 U.S.C. 552b(c) (3), and (7) to close meetings of the
Advisory Committee:
- (3) Disclose
matters specifically exempted from disclosure by statute,
provided that such statue (A) requires that the
matters be withheld from the public in such a manner as to
leave no discretion on the issue, or (B) established particular
criteria for withholding or refers to particular types of
matters to be withheld
- (7)
Disclose investigatory records compiled for law enforcement
purposes, or information which if written would be contained
in such records, but only to the extent that the production
of such records or information would (A) interfere with
enforcement proceedings, (B) deprive a person of a right to a fair trial
or an impartial adjudication, (C) constitute an unwarranted
invasion of personal privacy, (D) disclose the identity
of a confidential source and, in the case of a record compiled
by a criminal law enforcement authority in the course of
a criminal investigation, or by an agency conducting a lawful
national security intelligence investigation, confidential
information furnished only by the confidential source,
(E) disclose investigative techniques and procedures, or (F)
endanger the life or physical safety of law enforcement personnel
The most important thing is to let the system work for us
with the understanding that NIST has to follow procedures and
would have to go through both the DOC determination process
and the public notice process to get any proposed meeting closed.
NIST tried to anticipate reasons for closing these meetings
and more reasons may come up.
Q: Can you expand on criminal investigation information? How
does it apply to state and local authorities?
A: It’s possible that some agencies will share information
with us during an NCST investigation that is related to a criminal
investigation. We would have to close the meeting to discuss
that information. At the present time, we haven’t received
any such information so this issue has not yet come up.
Q: Under (9)(B), where does reviewing and commenting on the
NIST draft report fall?
A: An exemption is found in (c)(4). However, the DOC view is
that review of a draft report is not likely to frustrate agency
action.
Q: Draft reports are held confidential. We are asked to comment.
When we discuss these comments, the reports are no longer considered
confidential?
A: We are working with DOC to address this concern.
Q: How many people
are needed to form subcommittees—1,
2, 3?
A: We have not formed any subcommittees yet, but a subcommittee
can be any number of people, but of course more than one. The
recommendations and work of the Committee are consensus advice.
Work toward reaching a consensus is not necessarily public
and may involve individual discussions; the ultimate consensus
building is expected to occur in the open for the public to
review. The World Trade Center disaster was a once in a century
event. Everything we do will be scrutinized. The kinds of issues
being faced defy generalizations. When we get to specifics,
we will need to discuss and plan accordingly and work together
to allow the Committee to do its work within the constraints
of the law.
Q: The Committee members are broadly experienced. If two members
meet with a project team, is that a subcommittee? Does it have
to be advertised in the Federal Register?
A: When individual members of the Committee meet with project
teams, they may be learning, not performing a Committee function
and not working on building a consensus.
C: I had the understanding that closed sessions are necessary
to do Committee work and to understand the nitty gritty details
on an investigation.
Q: The Committee’s
report to Congress may require members to work together.
Can we clarify?
A: Drafting of the Committee’s report can be parceled
out, but consensus advice must come in a public meeting. A
draft of the report must be presented in a public session.
Advisory Committee members were encouraged to contact Mr.
Rubin with any other questions about the function of the Committee.
Back
to agenda NCST Act Requirements and Discussion
Dr. James E. Hill, Deputy Director, Building and Fire Research
Laboratory
PRESENTATION (pdf file)
Dr. James Hill gave
an update on the status of the NCST Act implementing procedures.
The Final Rule covering collection,
preservation, and protection of evidence collected and information
created was published in the Federal Register on May 7, 2003.
A Proposed Rule that covers other major implementing procedures
is under review at DOC. The Proposed Rule currently includes
sections on preliminary reconnaissance, building failure, conditions
for establishing a team (criteria for initiating an NCST investigation
by NIST), size and composition of a team, and typical tasks
in an investigation. Historically, in the United States, building
failures that have “resulted in substantial loss of life
or that posed significant potential for substantial loss of
life” have occurred less than once per year. This rate
of occurrence is likely to continue except for terrorist acts.
Dr. Hill also described
the NCST meeting on Interagency Collaboration, which was
held at NIST on July 31, 2003. This meeting explored
collaboration with other Federal agencies—attendees included
the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF);
Army Corps of Engineers; National Research Council; Federal
Emergency Management Agency; Chemical Safety Board; Federal
Bureau of Investigation; and National Transportation Safety
Board; among many others. Possible collaboration with NIST
may involve providing experts for reconnaissance and for teams,
supporting experiments, and making training available to team
members.
Q: With regard to the statement that information created by
NIST may not be used in any suit or action for damages, does
this refer only to civil actions? If the NCST investigation
is exposed to information that could be used in a criminal
investigation could it be used in a criminal case?
A: The answer to both questions is yes.
Q: If investigators
are refused timely access to a site, evidence may be lost.
Could NIST investigators have a “letter
in pocket” to help gain access? A Committee member stated
that he knows of several cases where critical evidence was
destroyed while awaiting access approval to a site.
A: We are building relationships with other agencies. Credentials
for investigators are also being considered. We are building
relationships with ATF and other critical agencies to help
investigators get access to sites.
Q: If investigators uncover evidence of faulty materials or
equipment that could be present elsewhere, are they precluded
from disclosing that information prior to the release of the
final report?
A: That is an excellent point. It is not something that we
have discussed yet.
C: However, the NCST Act is clear on the point that criminal
action takes precedence over NCST investigations.
C: (NIST) NIST relinquishes authority in a criminal investigation.
Constitutional law addresses search and seizure. If we are
denied access, procedures include constitutional provisions
for gaining entry. To the earlier question about disclosure
of information about faulty equipment, NIST would not wait
to communicate information if it was in the interest of public
safety and we were convinced of the matter. There may be more
ambiguity involved, however, and we need to be careful not
to draw false conclusions based on preliminary information.
C: (NIST) NIST has made public the preliminary findings in
the ongoing NCST investigations.
Q: Data collection is very important. Recruiting and training
is critical. In the case of human subjects, human subject clearances
and a certificate of confidentiality may be needed in advance
of an NCST investigation. How does the confidentiality of information
square with the Freedom of Information of Information Act (FOIA)?
A: NIST has some authority to protect confidential information.
Q: (Restating previous question) NIST may obtain information
it wants to protect. How do we square FOIA with the need to
protect data?
A: There are three levels of protection in the NCST Act. We
won’t make the data available until the conclusion of
the investigation. We may want to protect voluntarily supplied
safety information. Dr . Bement would need to make that determination.
We might want to have conversations with police and firefighters
that we would want to protect, under the premise that without
such protection, it would jeopardize their desire to provide
such information. Information that directly affects public
safety we will protect.
With regard to the
Certificate of Confidentiality: The Secretary of the Department
of Health and Human Services may authorize
protection of privacy of individuals participating in research
by withholding their names and other distinguishing characteristics.
For example, a person’s name and Social Security number
can be withheld. NIST is covered under FOIA section 6 and can
withhold information that would constitute an invasion of privacy.
Both are at the discretion of the Federal agency. A Certificate
of Confidentiality gains no further exemption beyond what NIST
already has.
C: Most prominent structural failures occur during construction.
NIST access to a site for these investigations should not be
an issue. Cover up of data and information should not be a
problem due to professional obligations and liability concerns.
It would be advantageous for NIST to develop a professional
relationship with the Occupational Safety and Health Administration
(OSHA). The OSHA requirement to publish a report in six months
sometimes hampers investigations, and NIST would be able to
investigate an accident for a longer period of time.
C: This is a follow up on earlier comment regarding the release
of public safety information. As an example, the work that
NIST did following the Northridge Earthquake on the failure
of welded steel moment frames; we would not want to withhold
information until the end of the NCST investigation if it affected
public safety.
C: Why do we say that we expect one NCST investigation per
year with the exception of terrorist acts? Suggest omitting
the statement regarding terrorist acts.
C: A substantial loss of life due to natural disasters may
mean multiple buildings in an NCST investigation.
A: We are not planning to state a number for loss of life in
the procedures for triggering an investigation.
C: I advocate a prescriptive approach for launching an NCST
investigation based on the number of fatalities. Every disaster
may have code compliance consequences. We need to be definitive
so the public would know when to expect an investigation to
be launched. Buildings burn to the ground everyday, but they
do not all warrant an NCST investigation.
Q: (NIST) Would a prescriptive approach be for the benefit
of the public, NIST, or both?
C: A prescriptive approach will help the public, with expectations
for when NIST will conduct NCST investigations.
C: (NIST) Implicit in the first bullet (slide 6) is a number.
We are considering the incidents where a relatively small number
of people died, but there is the possibility of a substantial
loss of life nationwide under similar circumstances. We are
open for suggestions.
Q: On slide 8, where do interior finishing materials fall
under the criteria?
A: The list on slide 8 is not meant to be all-inclusive. It
was an attempt to capture the things that might trigger an
NCST investigation. Clearly, materials that are determined
to be harmful would have to be considered.
Q: How easy will it be to determine whether a building failed
at less than the design value?
A: It may be impossible to make such a determination immediately.
It could take some time to make a decision.
C: In most building failures, it really does not take that
long and the reasons for structural failures can be determined
quickly.
Q: Are there situations where determining if a building failed
at less than the design value would be difficult?
A: (Committee Member) Yes, if failure occurs close to the design
loads for the building, making this determination becomes more
difficult.
Q: The intent of the criteria presented was to include failures
during construction and in service?
A: The NCST Act does cover failures during construction. OSHA
also has a responsibility and has the lead in construction
failures. We are working with OSHA, but do not have a signed
agreement with them at this point.
C: (NIST) Generally, OSHA handles construction failures. There
may be times in the future when NIST will participate with
OSHA in an NCST investigation.
C: (NIST) NIST needs to have teams established in advance
to advise on NCST investigations and to advise NIST on whether
to launch an investigation. The NTSB criteria for launching
an investigation are similar to what NIST is considering. The
Chemical Safety Board criteria are more prescriptive.
C: I understand the need for discretion. However, there needs
to be some level of understanding in the public for when an
NCST investigation would be launched.
Q: With respect to the size and composition of teams and typical
tasks, will a narrowly focused team have the expertise to identify
other possible failure modes?
A: An NCST investigation is not limited by the members of the
team itself. Additional expertise can be acquired from other
sources as needed. Consider the team in an organizational context;
once it starts, others can be brought in as needed. The composition
of a team does not have to remain fixed. It may change over
time as an investigation progresses.
Q: Was the Federal Emergency Management Agency (FEMA) at the
NCST Interagency Collaboration Meeting? What is their understanding
of how Building Performance Assessment Team (BPAT) efforts
would plug into NCST investigations?
A: The topic of FEMA’s BPAT efforts was not discussed
at the meeting.
C: The current FEMA administration position is that they will
never do another BPAT study.
Back
to agenda Status of WTC Investigation and Discussion
Dr. S. Shyam Sunder, Chief, Materials and Construction Research
Division
PRESENTATION (pdf file)
Fire
Test of WTC Office Workstation Video
[Descriptive Link]
Download RealOne
Player
Dr. Shyam Sunder is leading the NCST investigation of the
WTC disaster of September 11, 2001. He presented a briefing
on the status of the WTC investigation.
A progress report was issued on May 7, 2003. Dr. Sunder stated
that responses to the May 2003 WTC Investigation Progress Report
were particularly helpful and generated additional input to
the investigation team on the condition of the fireproofing
in the towers. The facts presented in the progress report have
not been questioned. It was suggested that NIST examine the
positive aspects of the buildings performance. Had the buildings
collapsed immediately, the number of casualties would have
been considerably higher. NIST will be objective in the investigation
and findings, but will point out both positive and negative
aspects of building performance as supported by the facts of
the investigation. NIST is not interested in evaluating the
buildings from the standpoint of designing a building to withstand
an aircraft impact.
Dr. Sunder reported that NIST has received a lot of critical
data since the last meeting that are being used by the different
project teams. Major media outlets have provided a considerable
amount of information that is being analyzed. Overall, significant
progress in data collection has been achieved since May 2003.
He also provided the status on the selection of external experts
and contractors. Six contracts have been awarded; six more
are pending. Nine experts are under contract, and four others
have been hired as expert consultants. The contracting process
is nearing completion, which thus far has successfully augmented
NIST in-house capabilities.
Dr. Sunder described the schedule and challenges of the WTC
investigation. The draft investigation report is scheduled
for September 2004. Challenges facing the team include the
massive amounts of data; level of complexity in fire-structure
modeling and collapse analysis; scope and scale of occupant
behavior, evacuation, and emergency response study; process
and time for acquiring outside expertise; and the Institutional
Review Board (IRB) and Paperwork Reduction Act (PRA) requirements
and process.
Over the last 12 months, however, the WTC investigation team
has made many key accomplishments. They have collected more
than 200 boxes of data from external sources and about 250
pieces of steel. Through analysis, they have determined the
mechanical and metallurgical properties of the recovered steel.
A structural database and model of the WTC towers has been
developed.
Other key accomplishments include the time-sequenced visual
analysis of fire and damage to the towers, fire dynamics and
thermal response modeling, and experimental validation of fire
dynamics and thermal-structural models. Computational interfaces
have been developed between fire and structural models and
software.
In addition, the methodology and protocols were developed
for the first-person data collection on occupant behavior,
evacuation, and emergency response. Team members extensively
reviewed Port Authority Police Department and New York Police
Department communications data.
Dr. Sunder described the WTC fire model input study, where
NIST created a computer workstation similar to one in WTC 1
and set it on fire. The results provided input for the Fire
Dynamics Model. The burn test video was shown.
The schedule for each project was briefly described, as well
as the interdependencies between projects. Dr. Sunder also
discussed the coupled analysis.
Q: How many proposals were submitted in response to the solicitation
for fire endurance testing of the WTC floor system?
A: Three.
Q: How were organizational conflict of interest issues dealt
with?
A: There were no organizational conflicts of interest disclosed
by the selected vendor. They are not a party to the investigation,
nor are they a target of the investigation. Their technical
proposal received the highest ranking of the proposals received.
Further, they had existing facilities available and are able
to perform 17-foot and 35-foot tests. A full-scale test of
a 60-foot floor assembly with uncertainty in controlling the
fire conditions was considered too risky.
Q: How can we move the data collection process forward?
A: We are continuing to pursue the original contract specifications
for the WTC towers and the construction and maintenance logs,
but this information is not considered crucial because we
already have a lot of this information. The 9-1-1 tapes and
logs and the transcripts from about 500 first responder interviews
are critical. We will ultimately need to go public if we
cannot get this information. Descriptions of partitions and
furnishings will be a bigger issue for WTC 7 than for the
towers. However, we will be able to do a credible job on
WTC 7 since we have cooperation from a tenant that occupied
26 floors, have structural data, and have data on the fuel
tanks used in the building.
C: There is a lot of missing data for Projects 7 and 8. We
need to continue pursuing the McKinsey data and 500 first responder
interviews.
A: NIST met with the commissioners of both the New York Police
Department (NYPD) and the Fire Department of New York (FDNY)
last week. We will need to reach agreements on the use of this
information. There are some legitimate concerns.
C: Wiss Janney Elstner (WJE) is trying to characterize all
pieces of steel NIST has from the buildings. I suggest concentrating
on pieces of interest from the impact zones and combining this
information with information from the photo enhancement work.
The combination would be very helpful to the analysis people.
The WJE work is also very important. I also encourage frequent
interaction among the staff working on Projects 2, 3, and 6.
C: (NIST) We will focus WJE on these immediate needs. We will
also work to improve interaction among project team staff.
Q: Is any of the missing information essential?
A: Yes. Tapes of 9-1-1 calls and transcripts of the 500 interviews
of first responders.
Q: Is there a plan “B”? What do you think is
in this information?
A: It may be very difficult to complete certain aspects of
the investigation without this information. We do not know
what information is contained in these sources.
Q: Could the interviews be recreated?
A: This would be harder than it might seem. The information
is now dated and the interviews were done on a voluntary basis.
Q: It is important
to think about a plan “B”.
Is there a trade-off between contract versus in-house work?
Some data we need up front. What about timing of solicitations?
A: We defined the plan first and then identified in-house expertise
and facilities. We could hire or build facilities. Hiring is
difficult due to the duration of the investigation. For example,
aircraft impact analysis, NIST did not have in-house expertise
to do this type of work, so we went outside to companies who
do this kind of work. For the E119 fire endurance testing,
NIST lacked facilities in-house to perform the testing.
Q: Interaction of fire and structural analyses needs to be
a two-way process. This is difficult to do if the work is divided
between contractors and in-house personnel.
A: Your point is well taken and we have started a parallel
effort to develop simplified structural-fire models to integrate
and test coupled failure analyses. The challenge to this team
is to come back in six months with results.
Q: You stated in your presentation that vents and fire growth
are not being addressed in the coupled analysis. Are venting
and fire growth and spread being considered?
A: We are starting with the damaged building ventilation paths
based on photographic information. The information is being
fed into the other projects up to structural collapse. Project
2 will provide additional information on the condition of the
building. This information will become input to the fire model
and then to the structural collapse model. We are not looking
at ventilation changes due to the collapse itself.
Q: How do you do the other parts of the analysis if you do
not deal with the vents?
A: We will identify boundary conditions (e.g., floor collapse),
the structural modeling may show that a floor collapsed and
that will be fed into the fire model.
C: You have to take the end conditions into account at the
beginning.
A: We are looking at particular points in time. Fire dynamics
models are a “halfway house” between uncoupled
and coupled models. The Fire Dynamics Simulator (FDS) only
works on surfaces large enough to resolve. We would be at a
loss if we had to predict loss of windows. All FDS calculations
have a minimum resolution of 50 cm. Trusses are smaller than
that. We are adapting the state of the art to the investigation.
A: The good news is that we were successful in the NIST Director’s
competence initiative to address the underpinning science to
provide a more rigorous basis for the future.
C: In summary, I have the following concerns:
- Concern
about the overall deadline.
- Absence
of information in some cases and information overload in
others.
- Prioritize
what information needs are critical. For example, 9-1-1
tapes were mentioned.
- Contingency
planning needs to take place now.
- Experimental
risk—whenever
you are doing experiments, there is the potential for
surprise results.
- Analytic
risk—coupled analysis;
complicated by the use of internal and external resources,
becomes a communications
issue.
- Need
to streamline requirements as much as possible.
Q: Is the original goal date still realistic?
A: We intend to complete the WTC investigation in that timeframe.
We are working with limited funding and have made promises
on when the investigation will be complete. We understand
that it is going to be tight. Our initial two-year schedule
was an estimate when we had much less information than we
do now.
C: The Advisory Committee will comment on the schedule in its
report.
Back
to agenda Project 7: Occupant Behavior, Egress, and Emergency Communications
Mr. Jason D. Averill, WTC Investigation, Project 7 Leader
PRESENTATION (pdf file)
Mr. Jason Averill
described the purpose and tasks of Project 7. He stated that
the purpose is to document the evacuation
by collecting and analyzing information on occupant behavior,
human factors, egress, emergency communications, and evacuation
systems. The tasks to accomplish this purpose include data
collection; methodology; review and analysis; and findings,
conclusions, and recommendations. The focus of Mr. Averill’s
presentation was on collecting data through first-person accounts.
The methods he discussed include face-to-face interviews (up
to 350 occupants of WTC 1, 2, and 7), telephone interviews
(800 occupants of WTC 1 and 2), and focus group interviews
(5 focus groups of about 10 people each).
Q: Has the draft survey instrument been completed?
A: Yes. It can be made available to the Advisory Committee.
Q: If it were one week after the event, would we need to seek
Paperwork Reduction Act (PRA) or Institutional Review Board
(IRB) clearance?
A: PRA pertains to survey research. It does not pertain to
nonstructured interviews of individuals. IRB review pertains
to human subjects research and is meant to protect the persons
involved. In the future, it will depend on what we hope to
get from interviews. NIST has decided to follow the Common
Rule for Human Subjects Research. It is possible to design
around PRA.
C: I recommend getting a pre-blessed questionnaire for use
in fact gathering at the scene of an accident.
A: We are trying to distinguish between interviews that are
unstructured as opposed to structured interviews. Such unstructured
interviews are outside of the purview of the PRA. However,
we are still concerned about the Common Rule.
C: It is necessary to have an appropriate level of sensitivity.
Some questions will be consistent among investigations. It
is very difficult if you’re trying to gather time-sensitive
information and three to six months is required to get approval.
The investigation team will be subject to the vagaries of other
people who have done interviews if they cannot interview people
at the scene.
C: Get pre-approval of instruments. I have been involved with
other investigations where we had IRB approved instruments
done in advance of the event of a similar accident.
*Recommendation: The Committee recommended NIST develop pre-approved
instruments.
C: (NIST) We would be interested in any input from the Advisory
Committee on this matter.
Q: What is the basis for the number of face-to-face versus
telephone interviews?
A: For the telephone interviews, the number of interviews were
determined based on the population size required to reach a
desired confidence level. For example, a 95% confidence level.
For the face-to-face interviews, we will use a snowball quota
approach to identify respondents. As we conduct the face-to-face
interviews, we will continue the interviews until we reach
data saturation. The number of face-to-face interviews was
estimated based upon taking a significant fraction of the selected
group.
C: (NIST) Family members will be handled differently than other
groups. The technical probes will differ for the other groups,
but the methodology will be the same.
Q: Why ask for unimpeded narrative without taping?
A: We are considering audiotaping.
C: I recommend taping the interviews and, if possible, having
them transcribed.
*Recommendation: The Committee recommended NIST tape and transcribe
interviews taken as part of the WTC investigation.
Q: Why did you choose 10 as the number of persons in each
focus group?
A: The actual size of the focus groups may vary.
C: Your contractor is probably aware of the guidelines for
focus groups.
A: We are looking at inviting a larger number of people to
ensure that we get enough respondents. We will recruit 10 persons
for each focus group with an expectation that 6 to 8 will participate.
Q: Why wouldn’t
you use both methods (telephone survey, face-to-face interviews)
on the same groups?
A: Telephone survey will provide data that will be generalizable
to the entire population of WTC 1 and 2. Face-to-face interviews
will focus on narrative details. We will make an effort not
to burden the same people.
Q: How will you establish a significant sample out of the
100,000 individuals present in the relevant universe?
A: The issue is whether the 100,000 names on the WTC badge
list contains the occupants who were present. One estimate
suggests that about 14% were present that day. How to identify
the occupants who survived? We will use a scientific sampling
method to identify occupants by zone. We will get phone numbers
for those persons and call. If they were an occupant, they
will be added to the group. Fourteen percent is not a formal
number. It is a working number. The statistical process will
hold true regardless of the number.
Q: What egress issues do you expect to address?
A: We
hope to be able to contribute to the thoughts about the size
of staircases, phased versus full building evacuation,
pre-movement time, and a better understanding about what
people think about before they evacuate.
Q: Despite the uniqueness of the buildings and the event,
do you think you can get generalizable data?
A: Yes.
Q: How does the flow of information work with a combination
of staff and contractors?
A: NuStats will assist NIST with the analysis of the data.
The outside experts we have hired will also assist NIST with
analysis of data.
Back
to agenda Project 8: Fire Service Technologies and Guidelines
Mr. J. R. Lawson, WTC Investigation, Project 8 Leader
PRESENTATION (pdf file)
Mr. Randall Lawson
presented the status of Project 8, which is focusing on evacuation
and firefighting. The tasks include
data collection, field interviews, and recreation and analysis.
NIST has collected and is reviewing documents, photographs,
videos, and audiotapes from the FDNY, NYPD, and the Port Authority
Police Department. Mr. Lawson described the field interviews
he is planning with FDNY, NYPD, Port Authority police, and
security personnel. Both face-to-face and focus group interviews
will be conducted. Different protocols will be used for the
face-to-face interviews in order to obtain broader results.
Some will be conducted using the semi-structured generic protocol;
others will be conducted with the investigative lead-following
protocol. Data analysis protocols will include computer-based
tools used for Project 7, Fire Fighter Line-of-Duty Death & Injury
Investigation from the International Association of Fire Fighters,
and Guide for Fire and Explosion Investigations from NFPA 921.
Q: The timing of the interviews is a concern. It is now more
than two years after the event, people can forget or revise
in their mind what happened. How do you address that?
A: We have a significant amount of data available to use for
correlation. We would very much like to get access to the 500
interviews already conducted. Cognitive interviewing techniques
and other methods will be used to address the timing issue.
C: The data that NIST needs will be very valuable (500 interviews,
McKinsey data) to anchor new data.
C: (NIST) The McKinsey work was done pro bono for New York
City. The city prefers that NIST work with them, not with McKinsey.
Q: Will you be able to resolve time and space (location of
individuals at specific times) inconsistencies?
A: We will attempt to set up a chronological order of events
and a database to resolve such concerns. Q: The use of NFPA
921 and IAFF protocols as shown in the presentation is good.
Information may also be available through
Columbia University who, as you know, is doing an evacuation
study; they are willing to share data with NIST. How does the
pro bono status of McKinsey’s work affect the city’s
ability to share the McKinsey report?
A: We are working with the city on this issue. Plan “B” if
the city does not voluntarily release report data will be difficult.
Back
to agenda Planning for Advisory Committee Annual Report to Congress
Mr. Paul M. Fitzgerald, Committee Chair
The Advisory Committee members discussed the format and content
of the annual report to Congress. Mr. Fitzgerald distributed
a draft outline to the members for their review and comment.
VIEW THE DRAFT OUTLINE
Mr. Fitzgerald suggested that the report be readable and limited
in the number of pages, with appendixes. It should be something
that people can pick up and use. This is an Advisory Committee
Report to Congress through NIST and the DOC. He proposed that
the report cover the topics shown in the outline. The Advisory
Committee members discussed the organization of the report
and writing assignments.
Q: Can you expand on the writing assignments?
A: (Committee Member) How we organize the report and its length
are open to discussion. I believe the report should be about
9 to 10 pages in length. Advisory Committee members may want
to comment based on their background.
Q: The intent of the legislation seems to be to comment on
the implementation of the NCST Act.
A: (Committee Member) The report is strictly a Committee report.
I agree that implementation of the NCST Act should be the focus
of the report.
Mr. Fitzgerald stated that there is general agreement on the
format of the report.
*Recommendation: The Committee recommended members be assigned
as leaders for each area of the report to prepare an initial
draft.
Paul Fitzgerald volunteered to do the executive summary and
Section 2 of the proposed outline.
C: (NIST) Any recommendations of the Advisory Committee presented
in the report should be considered in an open session.
Q: Are these recommendations to Congress through NIST?
A: (Committee Member) Yes. NIST will be interested in the report,
but audience is the congressional committees. Dr. Bement
has a set of questions that DOC and NIST need to hear back
from you on. We will also want to comment on advice from
the Committee.
C: Some of the comments today are recommendations to NIST.
C: The Committee can make more than one report to Congress
a year if it so desires. It can make recommendations and vote
on them in any open session of the Committee.
C: I looked at the report as a summation of the important things
done by the Advisory Committee during the past year.
C: What we did today was give NIST advice.
C: (NIST) As advisors, you should give NIST consensus advice.
C: We are giving recommendations to NIST throughout the year.
The report to Congress is how the Committee feels implementation
of the NCST Act was done during the year.
C: The cycle of recommendations relative to funding cycles
will be important. We need to understand how we can provide
input to budget issues to ensure that the NCST investigations
are adequately funded.
C: We need to fund core competencies, but the need to fund
extraordinary events will need to be considered on a case-by-case
basis.
Q: Can we make recommendations in an open meeting? What about
individual meetings? Are these considered Advisory Committee
recommendations?
A: We welcome all input, whether it is informal individual
comments or group consensus recommendations. We owe you a response
as to how we address your comments and recommendations.
C: We have spent a lot of time on the NCST investigations,
some on implementation. The concern is that there may be difficulty
in implementing the act. I am concerned that criminal investigations
may preclude the timeliness of the NCST investigations. The
report to Congress should have something to say.
C: (NIST) The Chair could compile thoughts for a more focused
discussion tomorrow.
C: The fundamental issue is the structure of the Advisory
Committee and the act. The criminal investigation element will
often be a hindrance. As you think of such issues, they should
be discussed by the Advisory Committee and included in the
report to Congress.
C: I will try to get these items out to the members so that
they can be discussed in an open session of our next meeting.
We need to have the content of the report complete by the December
meeting. Tomorrow we will discuss writing assignments. There
are many other things besides criminal investigations that
could delay access to a site that will need to be considered.
Public Comment Period
Mr. Fitzgerald stated the ground rules for public comments.
Each speaker has 5 minutes, and members of the public may submit
their comments in writing at the meeting or at any time. He
called the first speaker to the podium, Dr. Robyn Gershon,
who read a prepared statement.
Robyn Gershon, Columbia University
STATEMENT (pdf file)
Q: (for Robyn Gershon) Did you interview building security
people.
A: No, though some floor wardens were interviewed. Even some
of them did not know about all three emergency exits from the
buildings. Our study was primarily an occupational safety and
health study.
Mr. Fitzgerald called the next speaker, Mr. Francis Lombardi,
who read a prepared statement.
Francis Lombardi, Port Authority of New York and New Jersey
- I
am Frank Lombardi, the Chief Engineer of the Port Authority
of New York and New Jersey.
- I
am a survivor of the February 26, 1993, bombing and the
September 11, 2001,
WTC attacks.
- Thank
you and good afternoon.
- Port Authority staff suffered
terribly on September 11. This proud family of public employees
lost 84 of its own in
the attacks on the World Trade Center.
- Despite the overwhelming grief felt by
PA staff, they literally dusted themselves off that day and
went right back to work.
- Through their remarkable efforts
in the days and weeks that followed, they provided calm in
a time of chaos and security
in a time of uncertainty, helping with rescue and recovery
efforts and keeping vital public transportation facilities
open and safe.
- I am
here to express support for NIST’s
on-going investigation of the WTC buildings’ collapse
on September 11, 2001.
- We must learn from the past in order
to plan for what will come. We are hopeful that the outcome
of the current investigation
may yield insights that will help both the government and
private sector improve upon existing building and fire safety standards.
- I believe
that NIST is the appropriate federal agency to conduct
this investigation. The Port Authority of New York and
New Jersey has and will continue to cooperate with NIST in this
effort and will participate to the extent that we are
able. I believe that the findings and recommendations of
this
work will be extremely valuable to the building and fire safety
communities, and to the future safety and well-being
of the American public.
Mr. Fitzgerald called the next speaker, Mr. Jake Pauls.
Jake Pauls, Consulting Services in Building Use and Safety
- I
suggest using subcommittees and task groups to allow the
Advisory
Committee to do its work.
- I have
36 years of experience working on evacuations and have
worked on other advisory committees.
- I am
surprised that no member of the NIST WTC investigation
team has visited
or interviewed me. I have a wealth of
information on high-rise building evacuations that is available to NIST,
is located nearby, and have not had anyone look at this
information from the WTC investigation team.
- I recommend
the use of media databases. The media has gotten hold of
a lot of information and NIST
should be using
it. USA Today and the New York Times are two good examples.
- I find
it dubious that the language in the NCST Act will stop
information
from NCST investigations from being used
in subsequent legal actions.
- I was
at a recent conference on pedestrian evacuation in England
and I was surprised to see that none of the
consultants
hired by NIST to advise on the evacuation of the WTC towers were
there.
- NIST
should not overpromise results particularly in code development
and the standards process.
- With
regard to the IRB process—it
appears that hurdles set up by NIST have hurt cooperation
between
researchers. The UK team should be included in the evacuation study of
the WTC
towers. They have much more experience than
those currently involved.
- There
should be a focused meeting on the IRB process as soon
as possible to clear up any difficulties.
- We
need to bridge the gap between the researchers and the
media. The media appears to have more information
and it should be used.
- The
largest evacuation in history took place a week ago and
I have heard of no studies on it. (Referring
to the blackout of August 14, 2003.)
Mr. Fitzgerald called the next speaker, Ms. Monica Gabrielle,
who read a prepared statement.
Monica Gabrielle, Skyscraper Safety Campaign
STATEMENT (pdf file)
Mr. Fitzgerald called the next speaker, Mr. John Biechman,
who read a prepared statement.
John Biechman, National Fire Protection Association
STATEMENT (pdf file)
Comment Received Via Email
Sherman Rattner I have submitted numerous previous comments with respect to
the disaster of September 11th, 2001. Allow me to briefly reiterate
the sense of those comments for your consideration at their
inclusion at the next NCST Advisory Committee meeting.
It is my belief, which is shared by many experts, that the
innovative design of the WTC Towers resulted in their ability
to sustain the massive damage and remain standing for nearly
an hour each, thereby allowing thousands of individuals to
escape the buildings. It is furthermore, my belief that buildings
of more conventional post-beam-slab construction, which includes
the vast majority of high-rise structures would have begun
to collapse almost immediately faced with similar impacts.
Accordingly, if your investigation is to have any real significance
and value, I belief it must include the performance of conventional
type of structures under similar conditions as the type of
testing and simulation studies that you intend and have conducted,
with respect to the WTC towers.
Mr. Fitzgerald thanked the presenters, attendees, and speakers.
He adjourned the meeting at 5:15 p.m.
August 27, 2003
Mr. Fitzgerald called the meeting to order at 9:00 a.m.
Planning for Advisory Committee Annual Report to Congress
(Continued from Previous Day)
Mr. Paul M. Fitzgerald, Committee Chair
Mr. Fitzgerald continued
the discussion of preparing the annual report to Congress
from the prior day’s session.
Q: What does our report consist of?
A: Implementation of the NCST Act, recommendations for improving
implementation of the act, and recommendations for improving
the Advisory Committee role.
The following writing assignments were agreed upon by the
members:
| Paul
Fitzgerald |
Sections
1 and 2/Sections 3.4 and 4.4 |
| Bob
Hanson |
Sections
3.5 and 4.5 |
| Kathleen
Tierney |
Sections
3.1 and 4.1 |
| Phil
DiNenno/Charlie Thornton |
Sections
3.2 and 4.2 |
| David
Collins/John Bryan |
Sections
3.3 and 4.3 |
Mr. Fitzgerald listed the following issues for further discussion
by the Committee:
1. Revisit public comments regarding activities, authority,
role of the Committee (Jake Pauls)
2. Reference to contracts issued for egress study (Jake
Paul’s
offer to help).
3. Concern that Advisory Committee is operating in a closed
manner, “mouthpiece for NIST” (Monica Gabrielle)
4. Problems with data gathering, should NIST hold a public
hearing in New York City.
5. Role of Advisory Committee and external experts in launching
an NCST investigation.
- Establish
a standby panel of experts.
- Might
involve members of the Advisory Committee.
- Forensic
capabilities of NIST staff is a concern
- Experience
is along the lines of science and research
- Funding
of forensic experts to advise NIST Director?
- Funding
of future investigations
- Criminal
investigations versus NCST investigations
- Is lack
of cooperation in obtaining data a permanent impediment?
- Exemptions
from PRA, IRB, etc.
- Meeting
dates for next meeting
C: (NIST) Regarding forensic expertise: NCST investigations
are done as a team. Expertise may be present in others at the
scene. Teams could collaborate with others to obtain forensic
expertise or teams could be self-contained. With regard to
exemptions from PRA and IRB requirements, it would be more
appropriate to seek blanket approvals rather than exemptions.
Back
to agenda Project 3: Analysis of Structural Steel
Dr. Frank W. Gayle, WTC Investigation, Project 3 Leader
PRESENTATION (pdf file)
Dr. Frank Gayle
discussed the progress of the review and analysis of the
steel recovered from WTC 1 and 2. With assistance from
the Structural Engineering Association of New York and many
others, NIST has collected 236 pieces of steel, including perimeter
panel sections, box beams/core columns, wide flange trusses,
and bowtie pieces of exterior walls. Through extensive cataloging,
NIST has identified perimeter panel samples of all 14 grades
(i.e., yield strength) specified in structural steel drawings,
which are available for testing. Core column samples are available
of two grades (36 and 42 ksi) of both box and wide flange columns,
configurations that represent 99% of core columns in both towers.
In addition, Dr. Gayle’s investigation team has been
reviewing specifications and steel supplier documents, which
allow estimation of typical properties when specified minimum
yield strength is known.
NIST is currently conducting an analysis of the steel to document
failure mechanisms and damage. The analyses will provide observations
and statistics of repeated patterns of post-impact failures/fractures
of bolts, welds, truss seats, spandrel splices, and column
splices, as well as fire damage described as a function of
location (in or away from the impact zone or fires).
Dr. Gayle also described the tests being performed to determine
the mechanical properties of the steel: room temperature tensile,
high strain rate, and high temperature tests. The room temperature
tensile tests are being conducted on columns, spandrels, truss
components, seats, channels, plates, welds, and bolts to compare
with specified properties and provide data for characterizing
baseline structural performance of the towers. The high strain
rate test results will be used in the analysis of aircraft
impact damage and the analysis of most probable structural
collapse sequence. Those tests are being conducted on column,
spandrel, and bolt specimens. Aircraft impact led to strain
rates estimated at 100 to 1,000 per second. The high temperature
tests are being conducted to analyze the structural response
to fires. Dr. Gayle presented preliminary results; tests are
still ongoing.
Q: (NIST) Are we addressing notch sensitivity of the bolts?
A: We are performing Charpy tests on the bolts to determine
notch sensitivity.
C: In your comparison of strain rates, you stated that the
area under the curve is related to the energy absorbed. However,
that energy may not be uniformly distributed.
C: Suggest that you show the data as true stress-strain curves.
C: Behavior will depend on the geometry of the detail when
concentrating on fracture. One can go from a uniaxial stress
state with high energy absorption to a triaxial stress state
with low energy absorption that would change the failure mode
greatly. WJE should document impact zone pieces first. Also,
the massive amount of data available is a concern. Nothing
has yet been done on the weld metal. Task leaders should identify
the data needed to minimize the amount of work in the interest
of time and ensure that the key data is understood so that
the other projects know what data is available and Project
3 knows what data is needed to support the other projects.
C: (NIST) We have done some work on the weld metal properties.
We are also working with the other projects to identify their
needs, but need to continue to do so.
*Recommendation: The Committee recommended task leaders identify
the necessary input that they need to accomplish their objectives,
and where that need crosses over into another task, make sure
that the appropriate task leader is aware of the need and provides
the necessary data.
Q: (NIST) Can you think of situations where triaxial stress
might be important?
A: (Committee Member) In the Northridge Earthquake there was
evidence of a weld that came close to triaxial loading in tension.
There was no evidence of necking, it does not occur in a triaxial
loading state. Photographic data will be very useful to determine
loading states of welds.
C: You might not have a connection detail in triaxial loading.
MIT studies have addressed triaxial stresses.
Q: Weren’t
you attempting to characterize the maximum temperature of
the steel?
A: We are using visual inspection of the paint condition to
determine the temperatures to which the steel was exposed.
We reported on this work during the presentation at the April
Advisory Committee meeting.
Q: Are you looking at the effects of insulation on the steel?
A: We are conducting both analytical and experimental work.
Tests were conducted in February on bare and insulated steel.
We are working with the Fire Research Division to analyze
effects. Some of the concerns we are looking at include adhesion,
cohesion, the ability of the insulation to survive an impact,
and its tendency to separate.
Back
to agenda Project 6: Fire Endurance Testing of WTC Tower Typical Floor
Construction
Dr. John L. Gross, WTC Investigation, Project 6 Co-Leader
PRESENTATION (pdf file)
Dr. John Gross briefed the meeting attendees on the planned
testing of floor assemblies used in the WTC towers. The test
results will provide fire endurance ratings to evaluate test
scale, fireproofing thickness, and thermal restraint. Three
tests will be performed: 17-foot span assembly, thermally restrained;
35-foot span assembly, thermally restrained; and 35 foot span
assembly, thermally unrestrained. The tests will be conducted
in accordance with ASTM E119, Standard Test Methods for Fire
Tests of Building Construction and Materials. Dr. Gross discussed
the selection of key test parameters of fireproofing thickness
and steel specification. At issue is whether the planned tests
should address the fire endurance rating of the original specifications
or the as-built conditions.
Q: In the 35-foot furnace, will you be testing a long, narrow
floor assembly?
A: The test article will be 14 feet wide (width of the furnace).
Q: Can you describe the restraint?
A: The thermal restraint consists of concrete-filled steel
frame. Specimens bear against the frame.
Q: Will you also look at side restraints?
A: No. Only the ends of the specimen will be restrained.
Q: Were the 1999 Port Authority guidelines on fireproofing
thicknesses a requirement? How much work was done to upgrade
fireproofing and what was the quality of the work?
A: The Port Authority required that the guidance be followed
by tenants. Documents indicate that the guideline was followed.
Most floors in the impacted region of WTC 1 were upgraded.
A: Refer to page 81 of the May 2003 Progress Report.
C: Recommend re-creating the heat resistant factors present
on the affected floors as they existed on September 11, 2001,
including primer. Aircraft impact probably affected the insulation.
*Recommendation: The Committee recommended the closest representation
of as-built conditions be tested, including primer paint, ensuring
that the properties of the steel being tested match the steel
that was in the buildings as close as possible.
Q: Can you clarify the specified condition tests and why they
may be useful to the WTC investigation?
A: We have not been able to find a technical basis for the
fireproofing thickness selected for the floor trusses, and
it would provide additional information to the team.
Q: What fireproofing was still on the steel?
A: We have given considerable thought to the amount of insulation
that survived the impact. We are performing physical tests
and subjecting samples to accelerations. We are using analytical
tools to predict accelerations and compare results to experimental
data.
Q: Is there any indication that standard practice for supplying
structural steel is that the contractor exceeds the minimum
requirements? Is a test of reality (as-built condition) appropriate
to address actual practice?
A: We do not know what the general practice is. ASTM specifications
allow substitution of materials as long as they meet or exceed
the specification. The A36 steel specification is a loose specification.
Economic considerations may favor supplying a higher grade
steel.
C: Steel producers typically aim for 7 to 8 ksi above the minimum
specification to ensure that the steel meets the specification
in order to avoid scrapping steel. It was the case then and
it is now that A36 steel almost always comes out at 50 ksi
for angles and shapes.
C: The A36 specification dates back to the 1920s and 1930s.
Strengths began to increase after World War II and typically
were about 50 to 60 ksi based on structural reports I have
read that were prepared at the time.
Q: Can we assume that 50 ksi was representative of 1960s practice?
A: (Committee Member) The question is really more complicated
than that. Large plates can be affected by thickness and typically
process at about 36 to 50 ksi.
Q: What is the most
important property—that would govern
what is needed from the test?
A: We are planning to use A572 steel, which is similar to the
A242 that was used in building.
Q: (NIST) What about elevated temperature properties? How
would composition differences affect the properties of the
steel?
A: (Committee Member) A242 steel is no longer made. Chromium
may be present in A242 and could help in terms of elevated
temperature properties.
C: (NIST) These tests are not meant to perfectly reproduce
WTC conditions. The results will allow us to extrapolate to
conditions from data on rods and angles with varying levels
of insulation that will be present in the furnace during tests.
Q: Most structural engineers are satisfied to accept higher
strength materials over the minimum required except in high
seismic areas. Fireproofing is assumed to keep temperatures
of the steel relatively low. I am impressed with the approach
of the WTC investigation team: begin with components, then
address connections and assemblies. As you get to higher loads,
you begin to lose confidence in the models. Is SAP 2000 good
enough for this type of analysis? We have always looked to
the defense and aerospace industry for more sophisticated analysis
tools.
A: The SAP 2000 models are coming from LERA. However, we are
not relying on SAP for the modeling of the collapse sequence.
We will use ANSYS for the coupled, nonlinear analysis.
A: We also have LS-DYNA for dynamic analysis. We are encouraging
contractors to use other tools as long as the tools have been
validated. Coupling is a concern that we are addressing with
NIST Information Technology Laboratory (ITL).
C: Substitution for as-built condition is okay assuming that
performance of the materials is similar. An additional test
might be useful with lower strength steel (the minimum specified)
and different fireproofing thickness. There is almost no chance
of replicating the fire conditions. Coupons can be used to
address adhesion and cohesion properties of fireproofing (on
both primed and unprimed steel) and response to shock and vibration.
C: (NIST) We will take that suggestion under consideration.
C: (NIST) The standard test does not differentiate between
adhesion and cohesion. We have designed a way to address this
issue. We are estimating the g forces to which fireproofing
might have been subjected. Trusses rely on cohesion to retain
fireproofing. Columns rely on adhesion to retain fireproofing.
We are using a drop weight test to determine these properties.
C: (NIST) Weight is dropped on a beam. The height is varied
to change the acceleration. We should be able to predict the
acceleration at which the fireproofing comes off. Experiments
are being used to verify analysis.
C: I support the
suggestion to add an additional test. This should be a recommendation
of the Advisory Committee. There
will be very heavy scrutiny of this work. We need to make sure
the t’s are crossed and the i’s dotted.
*Recommendation: The Committee recommended NIST consider whether
an additional test is needed using lower strength steel (A36
or close substitute if unavailable) and different fireproofing
thicknesses that could have been present in the buildings based
on the specifications.
Q: In your background research, have you encountered tests
similar to the 35-foot scale?
A: No international tests have been located. Some work has
been done in the UK.
C: Ensure that the operating conditions of the furnaces are
good. I recommend that you be on the ground frequently during
specimen preparation and testing. Assemblies, restraints, and
welding need to be as close as possible for the 17-foot and
35-foot tests for the results to be comparable. A test with
A36 steel is important. If funds are not available for an additional
test, perhaps literature can provide data.
*Recommendation: The Committee recommended NIST be on-site
during specimen preparation and testing to check compliance
with test specifications, including assemblies, restraints,
and welding.
C: It should be possible to look at A36 steel within these
constraints.
C: In the 1960s, the E119 test was simply for temperature and
did not consider deformation. Data could be obtained analytically.
C: Check the Australian Institute of Steel as a possible source
of data.
Q: What is the status of specimen fabrication?
A: The contractor must submit drawings of the test specimens
for NIST approval.
C: A572 steel may be difficult to obtain.
Q: (NIST) Is A36 steel available in 2003?
A: (Committee Member) A36 steel is not available. Fifty ksi
material is probably ASTM 572 grade steel.
Q: (NIST) Should we still do a test with 0.5 inch thickness
of fireproofing?
A: (Committee Member) The sensitivity of the issue is a concern.
It would provide another data point.
Q: (NIST) Should an additional test be done at the 17-foot
or 35-foot length if such a test is possible?
A: (Committee Member) I would suggest 17-foot for cost reasons.
C: I recommend that tests should be investigative (as-built)
and include primer. NIST should also conduct an additional
17-foot test with A36 steel or a reasonable substitute at specified
conditions.
C: Assuming that an A36 steel is even available, yield strength
would be on the order of 42 ksi.
C: (NIST) The truss seats are the only true A36 steel in the
building. That material had a yield strength of approximately
42 ksi. The tension chord was approximately 55 ksi.
C: A lot of calculations
can be performed to look at the effect of insulation thickness.
You may not get your money’s
worth out of an additional test. The value of the additional
test is not obvious.
C: The decision has to be almost immediate.
C: This is time critical.
C: I advocate a conservative approach.
Status of the Rhode Island Nightclub Investigation
Dr. William L. Grosshandler, Chief, Fire Research Division
PRESENTATION (pdf file)
Dr. William Grosshandler is leading the NCST investigation
of The Station Nightclub fire that occurred in West Warwick,
Rhode Island on February 20, 2003. He presented a briefing
on the status of the investigation.
NIST is working with local, state, and Federal officials in
this investigation. Dr. Grosshandler introduced Chris Porreca
of the Bureau of Alcohol, Tobacco, Firearms and Explosives
(ATF). ATF and NIST are currently working on a memorandum of
understanding between the two agencies. The Station Nightclub
fire is the first time the two agencies have come together
under the NCST Act.
Mr. Porreca described how ATF responds to incidents at a local
level. If additional expertise is required, response can be
expanded to a regional level. If expertise beyond that available
at the regional level is needed, the response can be expanded
to a national level. The determination of expertise needed
is made at the scene. Agencies arriving at the scene of an
incident are not always on an equal basis. Criminal investigation
takes precedence. In the case of ATF, part of their charter
is to support local authorities in investigations. ATF is involved
with the investigation of the Station Nightclub fire at the
invitation of the Rhode Island Attorney General. Following
his remarks, Mr. Porreca left the meeting.
Dr. Grosshandler
clarified that the NCST investigation is being conducted
independently of the criminal investigation;
per the NCST Act, investigative priority is relinquished to
the criminal investigation being conducted by the Rhode Island
Attorney General’s office. Approximately 717 items of
evidence (including items held at NIST request) are being held
in a warehouse in Rhode Island. Access efforts are on hold
pending Federal court’s resolution of jurisdictional
issues in civil action.
The NCST investigation team has made progress establishing
initial conditions at the time of the fire, particularly the
dimensional floor plan; the locations of vents, doors, and
windows; and ceiling height above the stage and in the sunroom.
In addition, NIST is gathering data on the ceiling tiles, wall
lining, and types of acoustical foam.
A series of tests are in progress on a variety of materials
to develop source term data for modeling and to assess material
burning behavior to determine a correlation to the materials
in the nightclub. Plans include: cone calorimeter, corner experiments,
ignition experiments, and compartment experiments. Small-scale
tests are being conducted on different types of acoustical
foam for heat-release properties.
Dr. Grosshandler stated that the investigation will also analyze
occupant behavior and egress. Preliminary evacuation calculations
have been completed using evacuation models. A solicitation
has been announced for an egress study.
Q: When there is a suspicion of criminal activity, what limits
the ability of agencies to share information.
A: Release of information is the issue. It is possible to arrange
the exchange of information presuming that the information
can be protected. Different legal issues come up so the release
of information would need to be determined by the lawyers.
C: The NFPA Tentative Interim Amendment (TIA) process covers
not only clubs, but all assembly occupancies.
Q: What was the occupancy of the Station?
A: It was 317; 400 if tables and chairs were removed.
Q: What is the range of heat release of the foam?
A: About 600 to 1,000 kilowatts per square meter.
Q: Can information on the geometry of the club be recreated
if it is not available from the Attorney General?
A: The Attorney General has mapping. We are also pursuing interviews
to try and recreate.
Q: It is a good idea to test a range of materials. Do you
plan to conduct systematic interviews of survivors?
A: We are planning a public meeting in Providence in the next
few months. We will be asking for information. The meeting
will be an opportunity for the public to tell their stories.
Q: No interviewing is planned?
A: People may not be able to speak until after the criminal
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