Citation preview
Microsoft Word - May Newsletter 2005.docPaul Eng-WONG ()
Eng-Wong, Taub & Associates
NEW MEMBERS
We would like to express our warmest welcome to our new members:
Full members
Huajing SHI Mei ZHANG
Jay JUANG Yuebin LI Richard PETERS CHANGE OF PERSONAL
PARTICULARS
To keep our member records up-to-date, please let us know if you
have recently changed any of your personal particulars. You
can
simply return the form enclosed on the back of this newsletter to
Leo or send us an email with your updates to ictpa_ne@yahoo.com .
Since 2004, we have distributed our newsletters via email,
therefore, it is very important for us to have your most updated
email address in our database. If you have changed your email
address or if you have come across members haven’t received our
newsletters for some time, kindly advise them to update us with
their new information.
TRANSLETTER Volume 29
~Page 2 of 19 ~
Kuo-ann CHIAO ()
Peter LAI ()
Man-chung TANG ()
Feng-bao LIN ()
Cynthia CHEN ()
Publication Editors
Email
ictpa_ne@yahoo.com
Website
http://www..ictpaweb.org/templates/
usne_index.dwt
MEMBERSHIP You don’t have to be a transportation or traffic
professional to become a member of the ICTPA/US Northeastern
Chapter. Anyone engaged in or interesting in transportation may
join including students enrolled in a graduated or undergraduate
school of recognized standing, pursuing a course of study in
transportation related field is welcome. Chapter brochure and
application form can be downloaded from the following website:
http://www..ictpaweb.org/templates/usne_index.dwt. 2005 TECHNICAL
TOUR: APM TERMINAL As part of our 2005 technical series, there will
be a technical tour to the APM terminal at Port Elizabeth in June.
Date: June 3rd, 2005 (Fri.) Time: 2:00 pm to 3:00 pm approximately
Place: APM terminal, Port Elizabeth, New Jersey Tour: 1. Terminal
History 2. Tour around the APM Terminal and 3. Vessel Operation
Registration: For those who are interested, please send an email to
both: 1. ICTPA at ictpa_ne@yahoo.com and 2. Dr. Cynthia Chen at
chen@ce.ccny.cuny.edu on or before May 20th (Fri.)to register.
Transportation: Free shuttle service from New York City will be
provided (detailed arrangement will be announced later). For
information of this technical tour, please go to our website:
http://www.ictpaweb.org/templates/usne_index.dwt. If you have
further enquiry, contact us at ictpa_ne@yahoo.com
May 2005
MEMBERSHIP/BOD MEETING
You are cordially invited to the upcoming membership/BOD meeting
which will be held on June 2, 2005 (Thu) in Chinatown, NY. Details
of the meeting are as follow: Date: June 2, 2005 (Thu) Time: 6:30
p.m. Place: Basement, Wo Hop Restaurant 15 Mott Street (212)
962-6475) A reminder will be sent through email prior to the
meeting. For inquiry, please email to ictpa_ne@yahoo.com. 2005
ANNUAL MEETING
On behalf of the Annual Meeting Committee, we invite you to
participate in the 12th International Chinese Transportation
Professional Association – Northeastern Chapter (ICTPA-NE) Annual
Meeting: Date: October 1, 2005 (Sat) Venue: Sheraton La Guardia
East Hotel, Flushing Center, NY You will have an unparalleled
opportunity to share your knowledge and perspectives with
colleagues and to learn about the latest developments in
transportation planning, operations, management practices and
research through the Technical Sessions, roundtable discussions and
one-to-one dialogue with other members at this annual meeting. The
12th ICPTA-NE Annual Meeting covers two programs: the technical
seminars and the annual banquet. The tentative theme of this annual
meeting is “Providing an Efficient, Secure, and Integrated
Transportation System”. We will keep you update with detailed
information of this upcoming annual event through emails. So stay
tune and save the date!
TRANSLETTER Volume 29
~Page 4 of 19 ~
We are honored to have a chance to look at the live performance of
Tai Ji by Master Chen Si Tan, the Prince of Tai Ji in China.
ICTPA HONG KONG/MACAU CONFERENCE 5/29-6/1, 2006-- CALL FOR
PAPERS
The ICTPA Hong Kong/Macau Conference will be held in Hong Kong and
Macau from 5/29-6/1, 2006. We are now calling papers on the theme
of “Transportation, Economic Development and the Environment - A
Balanced System Strategy”. If you are interested to participate and
present papers at the conference, please contact Dr. David Shen
(see below) and all abstracts are due by November 10, 2005. Dr. L.
David Shen, P.E. Technical Program Chair Associate Dean and
Professor FIU College of Engineering, EC-2471 10555 W. Flagler
Street Miami, FL 33174 E-mail: SHENL@FIU.EDU
You will be able to find detailed information in the Annex 1. EARLY
SPRING GATHERING AT PHILIP LIU’S
MANSION IN PRINCETON
By Jing Du, Richard Graf (Jing Du’ husband) and Sarah Wu
On Saturday, March 19, 2005, over 50 ICTPA members and their
families gathered at our founding member, Philip Liu’s house in
Princeton for a fun get-together to kick off the spring. Philip’s
house is amazingly huge to accommodate all of us with plenty of
cozy chairs and sofa around the house, upstairs and downstairs.
They entertained us with Chinese Mahjong () and play-cards in the
living room; documentary movies about our earth
in the basement home theatre; and a fabulous Tai Ji (or Tai Chi)
(
May 2005
~Page 5 of 19 ~
Dinner table was full of delicious dishes prepared by many of our
members and friends.
) presentation in the party hall. Master Chen Si Tan, the Tai Ji
prince of China, winner of many global competitive Tai Ji event
medals, took us to a different world where the essence of our
splendid culture manifests itself in a “thinker’s sport” that is
Tai Ji. He gave us the basic concepts of Tai Ji and led a group of
eager learners in beginners’ steps to have a feel of this wonderful
form of exercise. The guests are pleasantly surprised by Philip and
his wife, May’s talent to keep an indoor pond with gold fish in the
top form. Surrounded by green trees and shrubs, the pond and its
marine life is the warm, spiritual heart of the house. We felt that
we were having a half day vacation at their house by seating around
the pond for relaxing. Before dinner, we also watched a
documentary, “The End of Suburbia” that was specially brought in by
our President Pan Wen Min. The movie deals with our future crisis,
in the areas
of energy and transportation. A couple of scientists spoke about
global consumption of natural Gas, oil and petroleum products, and
electricity. They predicted that around the year 2010, the World’s
oil production will have peaked and we would be started on the
downhill slide to where less and less oil will be able to be
produced from the world’s oil rigs. This will have astronomical
affects on our current lifestyle in the ways of transportation,
cooking, and heating and also affect the luxuries commonly
associated with the American “way of life”. We need to come up with
alternative solutions to our current lifestyle that doesn’t consume
as much oil. The program mentioned the hydrogen fuel cells of the
proposed cars of 2006. It stated that there was more oil consumed
to produce the hydrogen fuel cells than our current cars are
consuming. The program also spoke about the blackout on August 14th
2003. They said that it was caused by the constant increase in
demand of Electricity. One scientist said that it happened on the
first day that the temperature went above 90 and people were all
starting to use their air conditioners in both Canada and the U.S.
The program also spoke about the Iraq war and commented on some
reasons of why Bush invaded Iraq. One person stated that he
believed that it is because most of the World’s oil is in Iraq and
that is why Bush decided to take Saddam out of power and not
because of nuclear weapons. One wonders whether all statements made
in the documentary are accurate in light of alternative thoughts on
the same subject. However, this movie makes one feel that depletion
of our resources is a very urgent topic and we truly need to come
up with solutions now or else it will be too late. I don’t think
any of us would like to see a
TRANSLETTER Volume 29
~Page 6 of 19 ~
After dinner, the dance floor was open to all dancing enthusiasts.
Dr. Yu-fan Zhang (left) and her husband were just two of them who
were enjoying dancing on that night.
Dr. Lin and his wife are talented signers
repeat of the late 70s energy crisis! The dinner is splendid; we
had about 30 different dishes. Some of them were brought by our
members’ fresh cooking from home and others were grilled at
Philip’s kitchen by our two dedicated members Jiang, Zifeng and Lu,
Zhong, and Liu’s friends. Liu An-Zhong. Philip generously donated
his best Chinese liquor – Guizhou Maotai to the dinner tables.
Within minutes, we observed a few pretty blushing faces among
us.
After dinner Karaoke became the highlight of the party, we have so
many talented professional and amateur singers show us their high
notes. We had the opportunity to enjoy a former professional
actress performed which we do not have chance to hear much in
America; we also enjoyed a Taiwan TV station anchor woman’s high
notes as well. Everyone is trying to find the song number from the
Karaoke book to sing, which become such a hot item in the party.
Jerry and his daughter Katie were great performers,
they both sang a couple of America songs and got the highest 94
scores for star performance. Needless to say, our dear
friend Cao, You Quin was the most dedicated DJ who arranged for the
DVDs and stereo systems so that all can sing their heart out with
content. As time pushed onto 9 p.m., we saw dancing enthusiasts
practiced their tango, cha-cha, and fox steps in the party hall.
Disco music attracted a larger numbers to the floor, at least to
digest some of the dinner food. Furthermore, three delicious cakes
were brought out, followed by the entire group cheering for
birthday wishes for Mrs. Liu, May Yin. Philip thanked us with such
a relief, that since he was going to be away on his wife’s real
birthday, the party was saving him from potential troubles.
May 2005
~Page 7 of 19 ~
Speakers of technical seminar (from left): Mr. J. Juang, Mr. C.
Guan, Dr. Rachel Liu (moderator of the seminar), Ms K. Leone and
Mr. T Davis
Our party was not adjured till late 11:00 PM. Some stragglers left
for their homes even later, so we heard. What remains for all of us
are good memories of the evening. Thanks from ICTPA-USNE and all
guests go to Mr and Mrs Philip Liu for their hard work and
hospitality to make everyone feel so welcome and happy at their big
home! REPORT ON ICTPA –NE CHAPTER 2005 TECHNICAL SEMINAR
By Peter Lai The Northeast Chapter of ICTPA had conducted a
technical seminar on the Saturday afternoon of April 16, 2005. We
were pleased to hold the seminar at the beautiful facility of New
Jersey Institute of Technology, and our thanks to Prof. Rachel Liu
and Prof. Steven Chien for their efforts in securing the meeting
facility. Despite the fact that it was a warm sunny Saturday
afternoon, perhaps the best day of the year - close to 40 plus
participants showed up for the occasion. The main technical theme
for the seminar was “Trans-Pacific Freight Movement and Its
Implications in
North East Area”. It mainly focused on goods movement and the
following speakers made excellent presentations on various
interesting topics:
1. K. Leone, Homeland Security Institute, Arlington, VA - “Secure
Our Ports – Safety and Security Measures Applied in the Ferry
Transportation Systems”
2. T. Davis, Manager, Bureau of Freight Planning
and Intermodal Coordination, NJDOT and P. Lai,
Parsons Brinckerhoff, Quade & Douglas, Inc. -
“Development of a Comprehensive Freight Plan – A New Jersey
Perspective”
3. C. Guan, U.S. Merchant Marine Academy, Kings
Point NY - “Newly Erected Container Regulations and Initiatives and
Their Impact on the Supply Chain Community in the Tri-state
Area”
4. J. Juang, Liberty International Underwriters, New
York, NY - “Reducing Terminal Gate-in Delays: a
TRANSLETTER Volume 29
~Page 8 of 19 ~
VIP Panelists (from right): Mr. Wen Jin Lee, Mr. Jerry Cheng, Mr.
Peter Lai (also the moderator of this Professional Career
Development Roundtable), Mr. Paul Eng-Wong and Dr. Steven
Chien
Rational Approach to the State Bills in the U.S.”
A great deal of questions and discussions were shared among the
speakers and the audience just that at the end of the session,
everyone felt that they are more knowledgeable on several important
facts and issues associated with freight services in the New
York/New Jersey region.
After a 10-minute tea and soda break, we continued with the
remainder of the seminar – the “Professional Career
Development Roundtable”. It was perhaps the first of its kind in
recent NE Chapter history where a panel of reputable career
professionals interacted and shared with the audience their
experiences and lessons learned. Peter Lai served as the moderator
and conducted the roundtable in an interactive, informal Q&A
format.
The VIP panelists included Mr. Jerry Cheng, Principle
Transportation Planner, Department of City Planning, NYC; Mr. Paul
Eng-Wong, Principal, Eng-Wong, Taub & Associates; Dr. Steven
Chien, Associate Professor, NJIT; and Mr. Wen-Jin Lee, Sr. VP of
Operations, Yang Ming Line. The panelists came from the public,
consultant, industry and academic sectors, and were most suitable
to take on the selected discussion topic - “Considerations
for
a Successful Professional Career in Transportation”. The objective
was to identify the important ingredients for
a successful transportation career.
After close to 90 minutes of interactive participations from both
the panel and the audience (it would be even longer if not because
dinner was delivered and ready). Peter then summarized all key
discussion elements and concluded that a successful career depends
largely on the following ingredient categories: (1) Technical
skill; (2) Management skill; (3) Communication skill; (4)
Commitments and interests; (5) Personality and style; and (6)
Opportunities and fate. It was also agreed by everyone that the
degree of importance of these categories varies among different
transportation sectors, and there is no single most important
element. Peter also suggested that the Career Development Committee
of the NE Chapter to conduct additional series of workshops or
roundtables
May 2005
~Page 9 of 19 ~
People who were attending the seminar and career development
roundtable at NJIT
focusing on specific category.
After the completion of the roundtable, everyone gathered to enjoy
a delicious buffet style Chinese dinner while our Chapter President
Ms. Pan Wen-Min conducted the luck drawings with marvelous door
prizes. Among the lucky winners were Leo Tsang who drawn a karaoke
machine; Mrs. Tina Tang and Ms. Yuebin Li each drawn a portable DVD
player. The dinner concluded around 8 p.m. with a warmed farewell
from everyone as we all look forward to the opportunity – the
upcoming technical tour of the APM Terminal at Port Elizabeth on
June 3, 2005.
It was indeed a very successful seminar, and it will not
materialized without the hard work and dedication of our
Chairperson Prof. Rachel Liu, who had a head start in planning,
organizing and coordinating the key elements of the event including
the participations of the four invited guest speakers and served as
the moderator in the seminar. Therefore, on behalf of all members
and participants, our thanks go to Prof. Liu, all invited speakers
and panelists for their supports, the Technical Seminar committee
for their efforts and last but not the least, the Evergreen America
Corporation for their sponsorship.
TRANSLETTER Volume 29
~Page 10 of 19 ~
STRUCTURES IN NEW YORK CITY
By Feng Bao LIN ABSTRACT
New York City Department of Transportation (NYCDOT) owns more than
750 bridges in the city. Most of these bridges were built before
the seismic requirements for the city were implemented. To fulfill
these later adopted requirements, the existing bridges must be
evaluated and it is predictable that most of these bridges need to
be retrofitted for seismic resistance enhancement. Unreinforced
masonry bridge towers and piers, which are particularly vulnerable
to an earthquake, can be found in many bridges in New York City.
Seismic modeling and analysis of these structures represents a very
complex problem. A realistic modeling should capture the block
deformation, contacts and interactions between blocks, and crack
opening and joint sliding through the joining material. The main
objective of this research study is to develop an adequate
methodology to simulate the behavior of unreinforced masonry
structures under seismic excitations. A special finite element
approach and the discrete element method will be applied to model
and analyze typical masonry bridge components including the bridge
towers of the Brooklyn Bridge. The analysis results will be
compared, and the result accuracy, the numerical efficiency, and
the effects of different numerical algorithms will be examined to
determine the most suitable approach for the seismic evaluation of
masonry structures. (full text is attached in Annex 2)
May 2005
A THOUGHT TO THE CASE OF TERRY SCHIAVO
By Bosco Tong On the controversial case of Terry Schiavo there has
been unpreceeded and widespread national and international
interest, for which, we, as good citizens living in this country
of, for and by its people, would be remiss if we choose to bypass
its important underlying issues. As a pro-life advocate, I am of
the opinion that the preservation of any human being's continual
existence, especially in the case where the subject person is
unable to protect him or herself from external mortal harm, should
rule above the fundamentals of any constitution. From a
pragmaticist's perspective, the principles of argument have to be,
in my opinion:
First and foremost, the quest for a viable state-of-the-art medical
solution, exercising due diligence and beyond reasonable doubt, has
to be thorough and exhaustive. Where there is any hesitation,
however slight, expressed by experts in the profession, the state
must rule in favor of the continuation of life.
That established, each case will have to be separately examined in
sequence as follow: In the case where the subject person is,
without force majuere, and coherently able to, or has left explicit
and unambiguous instructions to a desired "course of action", that
"will" will have to be respected. Absent the above, decisions
should then, in that order, fall into the hands of those who are
close to the subject person(s) best able to represent the latter's
greatest interest. Where there is more than one wish and one voice
amongst the group of "well wishers", the law stumbles into
difficult grounds. While the law is mostly clear
TRANSLETTER Volume 29
~Page 12 of 19 ~
as to who comes first, second, and so on in the line of succession
of decision ownership, emotional feelings, bitter disputes between
close relatives, and in certain circumstances, as is the case in
point, the public, often tend to cloud the issue. Interference and
opinions from third party external agencies, such as the "faceless"
state, is arguably least desirable, in order that the sovereign
principles of separation between religion and ethics from those of
the state and the judiciary system, will be strictly enforced. The
law, of course, is necessary to serve as, but no more than, an
arbiter, ruling between the parties if and when in doubt and under
dispute. In the case of unborn babies, as in the case of Roe versus
Wade, even if they are conceived under non-consenting or
un-amicable circumstances, and notwithstanding that their ensuing
births may very well lead to probable hardship or burden, on either
the parents or on the state, be these burdens financial (as in a
lot of teen age pregnancy cases), emotional (such as children
expected to be born with birth defects), or some other things (for
example orphan-hood), applying the same rule that the state has a
duty of care to offer protection for those who are not in positions
to speak for and protect themselves, their lives should not be
terminated by a second, and least of all, a third party person or
entity, however intimate or remote the relationship. An interesting
case will be where the written "will" of the subject person
deviates significantly from that of his or her close family
members, and where contents of the "will" lack conclusiveness, the
state then has a duty to intervene, an obligation to interpret, and
perhaps a right to make the final decision, but in such case, must
act humanely and conservatively, to avoid the establishment of
unwarranted precedence, and to avoid any conceivable suffering.
Intermittent pulling and re-inserting the feeding tube, one argues,
is reflective of a wavering legal system contrary to the spirit of
foundation of constitution of this country. Author's Closure With
Terry Schiavo now dead, legal arguments over her case is no longer
meaningful. Instead her state of being post brain damage will be
examined more critically. Legal, theological, philosophical,
medical, ethical, social and political arguments aside, in real
life terms there is an earthly side of matters that should not be
overlooked. Mere existence by itself is NOT qualified as living.
Terry Schiavo, I submit, has ceased to live fifteen years
ago.
May 2005
~Page 13 of 19 ~
Being alive in a vegetative state, with no hope of reversal by
medical treatments we know how, does not constitute true living
embodying life's full implications, which is to grow and in time to
age, to have feelings of joy and sorrow, capable of enjoying things
we like, and disliking matters we hate, of surmounting difficulties
and enduring sufferings, being able to learn and to forget, to
laugh and to cry, to go to sleep when tired but waking up every
morning and be thankful that we are blessed with yet another day of
living, and above all, to love and be loved. Protectionalism,
especially when excessive, except in dealings with our young and
the helpless, the aged and disaffirmed (even here, one needs to be
careful and sensitive lest we fall into the trap of being over
zealous as to be intrusive), is generally counter-productive,
inhibits growth, discourages competition, promotes sense of
complacency, encourages laxness, and sets back progress of society.
**********************************************************----------------------------------------------------------------
If you would like to express your opinion and/or point of views
towards recent controversies, you are welcomed to send us what you
think. Basically, there is no limitation on both words and topics,
however, transportation related articles within 500 words are
mostly appreciated. Your articles will be circulated and reviewed
within the publication editorial board. Once you are selected, you
will receive a formal notice of selection with a date when your
article will be posted in the next issue. Your articles should send
to ictpa_ne@yahoo.com. Final decision and all right are reserved by
the ICTPA Northeastern chapter publication editorial board.
----------------------------------------------------------------**********************************************************
TRANSLETTER Volume 29
~Page 14 of 19 ~
Name* (First) (Middle) (Last) (Chinese)
Email* Sex* M F
Phone ( ) - Fax ( )-
Phone ( ) - Fax ( )-
* Required Date (mm/dd/yy): 1 Check either one
----------
--------------------------------------------------------------------------------------------------------------------
----------
ICTPA-USNE 3rd Fl. One Penn Plaza New York NY 10119 Attn Ms Wen-min
PAN Parsons Brinckerhoff
TRANSLETTER Volume 29
~Page 18 of 19 ~
STRUCTURES IN NEW YORK CITY
By Feng Bao LIN (Full text)
SEISMIC ANALYSIS OF UNREINFORCED MASONRY BRIDGE STRUCTURES IN NEW
YORK CITY
Feng-Bao Lin
INTRODUCTION New York City Department of Transportation (NYCDOT)
owns about 750 bridges among a total of more than 2,100 bridges in
New York City. Most of these bridges were built before the seismic
requirements for the city were implemented. Soon after the 1989
Loma Prieta earthquake in San Francisco, many states in the central
and eastern United States including New York State adopted
provisions for seismic design of highway bridges. To fulfill these
seismic requirements, the existing bridges in New York City must be
evaluated and it is predictable that most of these bridges need to
be retrofitted for seismic resistance enhancement. Among the major
long-span bridges in the city, Williamsburg Bridge was evaluated
and the seismic retrofit is in progress, Manhattan Bridge is
currently under evaluation, Brooklyn Bridge will soon be evaluated,
and Queensboro Bridge was evaluated but needs to be re-evaluated
[Khinda 2001]. Unreinforced masonry structures are used in many
bridges in New York City, ranging from the towers of long-span
Brooklyn Bridge to the piers of short-span 145th Street Bridge.
These unreinforced masonry components are particularly vulnerable
to an earthquake because the integrity of unreinforced masonry
structures mainly relies on the joining material between masonry
blocks such as mortar which is very apt to crack when subjected to
tension. One key aspect in the seismic evaluation process is to
create a sound structural model and perform numerical seismic
analyses. The numerical modeling and analysis of unreinforced
masonry structures represents a very complex problem because of the
constitutive nature of masonry. Being composed of two very
different materials, the masonry units and a joining material,
masonry structures exhibit a heterogeneous and discontinuous
behavior. A realistic modeling should capture the block
deformation, contacts and interactions between blocks as well as
crack opening, crack propagation, and joint sliding through the
joining material. The main objective of this research study is to
develop an adequate methodology to simulate the behavior of
unreinforced masonry structures under seismic excitations. A
special finite element approach and the discrete element method
will be applied to model and analyze typical masonry bridge
components including the bridge towers of the Brooklyn Bridge. The
analysis results will be compared, and the result accuracy, the
numerical efficiency, and the effects of different numerical
algorithms will be examined to determine the most suitable approach
for the seismic evaluation of masonry structures. FINITE ELEMENT
ANALYSIS WITH SLANTED ELLIPSE MODEL The finite element method is
the most powerful, versatile, and well-established numerical
approach. The key aspect in the numerical analysis of masonry
structures is how to simulate
crack propagation in the mortar between masonry blocks. The
cracking can be modeled in a finite element analysis by adjustments
of material stiffness. This approach, called smeared cracking,
requires a realistic constitutive model that can simulate
strain-softening behavior. Strain softening is a phenomenon
reflecting microcracking on the macroscopic level in which the
stress declines gradually at increasing strain due to the growing
of microcracks and finally reduces to zero as the microcracks
develop into a major visible crack. The slanted ellipse model [Lin
et al. 1987, Jirasek and Bazant 2002], which was developed by the
principal investigator, will be modified and integrated with the
general-purpose finite element program, ABAQUS, to simulate crack
propagation for the proposed study. The slanted ellipse model is a
plasticity-based constitutive model developed particularly for
concrete materials. The yield or loading surface of this model is
smooth without corners. It has the shape of a rounded triangle in
the deviatoric sections and the shape of a slanted ellipse in the
meridian planes (Figure 1). The model is able to describe hardening
or softening response caused by either pore collapse or
microcracking in a material. When the volumetric plastic strain is
negative, i.e., when the pores in the material are closing due to
high hydrostatic compression, the material hardens. When the
volumetric plastic strain is positive which indicates inelastic
volume expansion due to microcracking, the material softens. The
inelastic hydrostatic response can also be simulated by this model
because of its closed-type yielding surface. In addition, the
identification of the material parameters can be carried out
sequentially, rather than by simultaneous nonlinear optimization of
the fits of all data. It has been shown that the model agrees well
with the available test data of concrete under various loading
conditions [Lin et al. 1987]. The loading surface of the slanted
ellipse model can be expressed in the form:
0 0( ) 3 ( , / , ) 0cF r fσ τ θ σ τ′= − = (1)
where σ is the stress tensor whose Cartesian components are ijσ , 0
1 / 3Iσ = , 1 kkI σ= = first
invariant of stress tensor, 0 22 / 3Jτ = , 2 / 2ij ijJ s s= =
second invariant of the stress
deviator 1 3ij ij ij kks σ δ σ= − , ijδ = Kronecker delta, 11
3cos
3 2 θ −=
= similarity angle
which represents the polar angle in the deviatoric section, 3 1 3
ij jkJ s= kis s = third invariant of s , ij
cf ′ is the tensile strength, τ is a hardening-softening parameter
which determines the size of the loading surface, and function r 0(
, / , )cfθ σ τ′ represents the deviatoric section of the loading
surface which can be expressed by the Willam-Warnke’s formula as
(see Fig. 1):
2 1/ 2
2 20 2
(2 )(2 cos 5 4 )( , , ) , 2( )cos 2 cos (2 )
t c t t c c c t
c t c
R r r R r rrr r R r r f R r r σ θθ τ θ
θ + − + −
where and represent the tensile and compression meridians,
respectively, which have a slanted- ellipse shape (Figure 1).
tr cr
Tensile meridian (θ = 0): 1 22 30 0 0
0 1 2 33 ( )tr σ σ στ α α α α τ τ τ
( ) = + + + (3)
Compression meridian (θ = 60o): 1 220 0 0
0 1 2 33 ( )cr σ σ στ β β β β τ τ τ
3( ) = + + + (4)
These equations involve eight parameters 0 3 0, , , , , 3α α β β in
which only six are independent because the two apices of each
slanted ellipse must coincide. The hardening rule is governed
by
1 1 0 0 1exp( ) 0 3
p p kkforτ τ λ ε ε ε= − = p ≤ (5)
and the softening is governed by >2 2
1 2 0 0exp( ) 0p pforτ τ λ ε ε= − (6) where 1τ represents the
initial size of the loading surface and p
ijε is the inelastic strain.
Hardening and Softening Rules
Figure 1. Slanted Ellipse Model
The slanted ellipse model will be modified particularly for the
seismic analysis of the mortar materials. Different
hardening-softening rules such as kinematic and mixed
hardening-softening rules will be incorporated into the model to
simulate the cyclic behavior. The parameters 0 3, , ,α α
0, , 3β β will be calibrated based on the test data from the
uniaxial compression test, uniaxial tensile test, biaxial
compression test, and hydrostatic test on the mortar materials.
After several small-scale typical examples are analyzed to verify
the modified model, the study will then proceed to the analysis of
unreinforced masonry piers of the 145th Street Bridge and
unreinforced masonry towers of the Brooklyn Bridge in New York
City. The 145th Street Bridge is a swing span movable bridge
crossing the Harlem River and provides access between Manhattan and
the Bronx. The total length of the bridge is about 1,580 ft,
consisting of a 310 ft steel through-trusses swing span, steel
girder and truss approach spans, and earth-filled approach ramps.
The swing span is supported by a circular concrete pivot pier with
a granite block façade (Figure 2). The two river rest piers were
built by unreinforced stone masonry blocks founded on concrete
in-filled timber caissons.
Figure 2. 145th Street Bridge with Swing Span Supported by Masonry
Piers
The Brooklyn Bridge is a historic landmark which is the oldest of
all the East River crossings in New York City. The bridge is also a
vital transportation link from Manhattan to Brooklyn that must
continue to function after a seismic event. This suspension bridge
has diagonal stays radiating from the top of the towers. The bridge
is about 6,000 ft long including the main span, two side spans, and
two masonry approaches. The two towers of the bridge (Figure 3) are
massive masonry structures supported on sunken caissons and they
reach 270 ft above the water surface of the river. The masonry
bridge piers of the 145th Street Bridge and the bridge towers of
the Brooklyn Bridge are expected to play a significant role during
a seismic event. They exhibit a highly nonlinear behavior due to
the development of cracking. Since the masonry structures are
brittle, they may behave in an unsatisfactory manner leading to
serious damage or even a sudden collapse if the seismic loads
exceed a certain limit. A finite element model of the piers and
towers will be generated with the slanted ellipse constitutive
relationship applied to the mortar between the masonry blocks.
Step-by-step nonlinear time history analyses will be
conducted
using the ABAQUS program integrated with the slanted ellipse model.
The results of crack formation, crack propagation, displacements,
forces, and stresses due to selected earthquake excitations will be
used to evaluate the vulnerability of the piers and towers. The
force capacity- to-demand ratios and the ductility ratios will be
acquired from the analyses for the seismic performance evaluation.
To obtain the seismic vulnerability functions, the structural
response will be examined for increasing peak ground acceleration
values.
Figure 3. Masonry Tower of Brooklyn Bridge
SEISMIC EVALUATION USING DISCRETE ELEMENT METHOD The discrete
element method [Sincraian and Lemos 1998, Sincraian and Lemos 1999,
Azevedo et al. 2000] was developed in recent years for the analysis
of structures composed of particles or blocks, such as jointed and
fractured rocks or masonry structures. The method is especially
suitable for the problems in which a significant part of the
deformation is caused by the relative motion between the blocks.
The approach allows for large displacements, rotations, and sliding
between the blocks, the opening of cracks and even the complete
detachment of the blocks. The method is well suited for collapse
analysis, and may thus be an effective tool for the safety
assessment of the bridge masonry structures. However, this method
is not as well established and demonstrated as the finite element
method. Its applicability to the current proposed research needs to
be studied and verified. In the discrete element method, the blocks
may be assumed rigid or deformable. The
representation of the interface between blocks relies on sets of
point contacts which can be modeled using a soft contact approach
or a hard contact approach. In a soft contact approach, a finite
normal stiffness is taken to represent the measurable stiffness
that exists at a contact or joint. A small overlap of blocks is
possible in the case of compression. A hard contact approach will
not allow any interpenetration of the two blocks that form a
contact. A joint constitutive relation has to be provided for the
normal and shear directions. In the normal direction, the
stress-displacement relation is usually assumed linear. In the
shear direction, a Coulomb slip model is employed in which the
response is controlled by a constant shear stiffness and the shear
stress is limited by a combination of cohesion and friction between
the two blocks. The discrete element program UDEC [Itasca 1996]
will be used to perform the seismic analysis using a time
integration method. Similar procedures as stated in the previous
section will be carried out and the analysis results will be
compared with those obtained from the finite element method. The
applicability and effectiveness of the discrete element method for
seismic evaluation of masonry structures will be examined and
evaluated. Figure 4 shows an initial result of the masonry pier of
the 145th Street Bridge obtained from a discrete element analysis.
The figure indicates that some masonry blocks at the low-right
corner fall out of the pier during the seismic excitation. In this
analysis, the pier is subject to a seismic event developed by
NYCDOT for the 2500-year earthquake. The earthquake time history
was synthetically generated using an actually recorded earthquake
acceleration time history as a seed and then modified to match the
target design response spectra specified in the 1998 NYC Seismic
Hazard Study Report [NYCDOT 1998].
Figure 4. Model of the 145th Street Bridge Masonry Pier
CONCLUSION Taking the lessons from the 1989 Loma Prieta earthquake
in San Francisco and the 1994 Northridge earthquake in Los Angeles,
the general public and government officials in the United States
have a
heightened awareness of the structural and economical impact of
potential seismic hazards in a highly populated urban environment.
A regional economy can be dramatically affected by the closing of
an important transportation route. Recognizing these consequences
and the importance of seismic safety, many states have adopted
seismic safety provisions for highway bridges to assure that all
transportation structures are seismically safe and important
transportation structures maintain their function after an
earthquake. Since then, significant emphasis has been placed on
seismic evaluation and retrofit of existing bridges to fulfill the
safety requirements. Evaluation of masonry bridge components, which
are particular vulnerable to an earthquake, poses an important and
challenging issue and requires more research effort to solve the
complex problem. This research study consists of theoretical
formulations, numerical simulations, and engineering applications
to addresse an important and critical need for seismic modeling and
analysis of unreinforced masonry structures. Currently, there are
no effective approaches capable of modeling the block deformation,
contacts and interactions between blocks as well as crack opening,
crack propagation, and joint sliding through the joining material.
The success of this study would definitely advance the current
state of knowledge in the areas of seismic evaluation and retrofit
of masonry structures. REFERENCES 1. Azevedo, J., Sincraian, G. E.,
and Lemos, J. V. (2000), “Seismic Behavior of Blocky
Masonry Structures,” Earthquake Spectra, Vol. 16, No. 2, pp.
337-365. 2. Brebbia, C. A., Telles, J. C. F., and Wrobel, L. C.
(1984), “Boundary Element Techniques:
Theory and Applications in Engineering,” Springer-Verlag. 3. Itasca
Consulting Group, Inc. (1996), “UDEC – Universal Distinct Element
Code – User’s
Manual Version 3.0,” Minneapolis, MN. 4. Jirasek, M. and Bazant, Z.
P. (2002), “Inelastic Analysis of Structures,” John Wiley
&
Sons, London and New York. 5. Khinda, J. S., Ed. (2001),
“Infrastructure for Earthquakes–Seismic Retrofit of
Structures,”
Proceedings of ASCE Met Section Infrastructure Group Seminar,
Brooklyn, NY, March. 6. Lin, F. B., Bazant, Z. P.,Chern, J. C., and
Marchertas, A. H. (1987), “Concrete Model with
Normality and Sequential Identification,” Computers and Structures,
26(6). 7. Lin, F. B., Yan, G., Bazant, Z. P., and Ding, F. M.
(2002), “Nonlocal Strain-Softening
Model of Quasi-Brittle Materials Using Boundary Element Method,”
Journal of Engineering Analysis with Boundary Elements, Vol. 26,
No. 5, May, pp. 417-424.
8. New York City Department of Transportation (NYCDOT) (1998), “New
York City Seismic Hazard Study and its Engineering Application –
Final Report,” New York.
9. Sincraian, G. E., Lemos, J. V. (1998), “A Discrete Element
Program Based on a Rigid Block Formulation,” Report 40/98–NDE/NEE,
Laboratorio National de Engenharia Civil, Lisbon.
10. Sincraian, G. E. and Lemos, J. V. (1999), “Seismic Analysis of
a Stone Masonry Aqueduct Using Discrete Elements,” Proceeding of
8th Canadian Conference on Earthquake Engineering, Vancouver,
Canada, June 13-16, pp. 131-136.
May 2005
International Chinese Transportation
6th Asia-Pacific Transportation Development Conference & 19th
ICTPA Annual Meeting
May 29 – 31, 2006, Langham Place Hotel, Hong Kong
May 31 – June 1, 2006, Mandarin Oriental Hotel, Macau
CONFERENCE TOPICS The theme of the Conference is “Transportation,
Economic Development and the Environment - A Balanced System
Strategy”. Due to the continuing strong economic growth in the
Asia-Pacific region, many transportation planners/officials in the
area are facing a critical task of providing efficient
transportation systems to meet the needs of economic development
while minimizing the negative impact on the environment and the
quality of life. The conference goal is to gather world-wide
Chinese and international transportation professionals exchanging
ideas, sharing experience, and developing a list of recommendations
for future actions focusing on the following four (4) topics:
Topic #1 Multimodal Transportation Challenges in the 21st Century -
Policy, Technology, Planning, Operations, and Management –Issues
faced and potential solutions and strategies…
Topic #2 Balancing the Needs of People and Goods Movement in the
Urban Area – Truck/Freight modeling and planning, urban truck
traffic, commodity flows, logistics practices and trends…
Topic #3 Balancing the Needs for Mobility and the Environment –
alternative fuel, public transportation, strategies for reducing
trip making (carpool, telecommuting, flexible work hours…),
technology…
Topic #4 The Role of Transportation in Bridging the Gap between the
Developing Coastal Region and the Underdeveloped Western Region of
China – efficient financial investments, technology transfer,
professional developments, education & training,…
ABSTRACT SUBMITTAL
• Abstracts for publication will be considered. Once accepted, a
formal paper will be required for inclusion in the conference
proceedings. A presentation will also be included in the conference
program.
• Abstracts for presentation only on subjects related to sharing
experience and lessons learned will also be considered. Once
accepted, the presenter is required to submit a presentation
outline in PowerPoint format; no formal paper is required.
• Abstracts should be no more than 250 words in English or Chinese
and should be prepared in Microsoft Word 95 or higher. Please
indicate the abstract is for ‘publication and presentation’ or
‘presentation only’.
Please e-mail the abstracts to: Dr. L. David Shen, P.E. Technical
Program Chair Associate Dean and Professor FIU College of
Engineering, EC-2471 10555 W. Flagler Street Miami, FL 33174
E-mail: SHENL@FIU.EDU IMPORTANT DATES
• Abstract Due Date: November 10, 2005 • Acceptance Notification
Date: December 15, 2005 • Paper and Presentation Slides Due Date:
March 30, 2006 Please check www.ictpa.org often for the latest
information about the conference.
International Chinese Transportation
2006 5 29 31 Langham Place 5 31 6 1 Mandarin Oriental
(ICTPA) ICTPA
2006 5 29 6 1
2005 11 10 ICTPA 2006 —
/
—/
—(
) , –
Powerpoint 250 -- Microsoft Word 95
: Dr. L. David Shen, P.E. Technical Program Chair Associate Dean
and Professor FIU College of Engineering, EC-2471 10555 W. Flagler
Street Miami, FL 33174
E-mail: SHENL@FIU.EDU :
2005 11 10 2005 12 15 2006 3 30
www.ictpa.org
CONCLUSION