| Principal Investigator and Institution
George C. Lee, University at Buffalo
Objective
Special bridges are those long-span and spatially curved bridges that
require special considerations in their design and construction, in large
part due to their one-of-a-kind nature. Typically, complicated nonlinear
time-history analyses are involved in their design, which by itself is a
challenge to bridge structural engineers. Since relatively little is known
about how to design earthquake response modification systems for these
special bridges, it is difficult to develop standardized design procedures
and specification provisions. To address this need, the ultimate goal of
this task is to develop a monograph which will introduce general
principles followed by typical case studies of known examples, to benefit
those who have to design and retrofit such special bridges. In the first
year of this task (Research Year 3), the focus will be on collecting
information and knowledge from practitioners and researchers who have been
involved in the seismic design and retrofitting of such bridges both with,
and without, seismic response modification technologies.
Approach
Special bridges are typically one-of-a-kind, and each may have specific
dynamic characteristics that require special consideration in analysis and
design. To understand these special dynamic properties, experiences from
researchers and bridge design professionals will be sought. This will be
done in three separate efforts:
(1) Reviewing available literature including journal articles,
conference and workshop proceedings, published reports, and other
information available in printed or electronic form.
(2) Conducting one major and one small workshop. The first US-PRC
Workshop has been planned for September 12-15, 2002 (see Task G3-6) and
the results of this workshop will provide information on international
practices with respect to special bridges. A small, highly targeted,
workshop will be held in California in order to gather and assess
information and case studies on the design of special bridges which have
recently used response modification technologies.
(3) Meeting with other experts in special bridge design and retrofit,
and experts in Seismic Response Modification Device (SRMD) technologies.
This will be done by inviting a number of experts to Buffalo, New York for
one-on-one meetings, and to a meeting in Portland, Oregon in association
with the FHWA National Bridge Seismic Conference.
The small workshop described in (2) will build on and extend the
collection of knowledge obtained from the Long-Span Bridge Seismic
Research Workshop, which was held in San Francisco, California in December
1994 under the auspices of Task 106-F-5.2.1 of the FHWA Contract
DTFH61-92-C-00106 (Project 106). The workshop supported via Task D3-2 will
focus on design and retrofit information regarding SRMDs for special and
long-span bridges that use SRMDs. Up to ten bridge engineers in charge of
actual designs will be invited to share their expertise and experiences at
this workshop, which will be conducted in the summer of 2002.
This workshop is expected to result in sufficient information to
formulate the basic framework and approach for the development of a manual
on the application of SRMDs for special bridges.
Products
The end products for this research task are available targeted by
project 094, and the corresponding design approaches.
With such information, we can develop dynamic response modification
strategies for the targeted bridges.
The primary product of this task will be information on methods of
dynamic analysis to determine specific response characteristics of
components and for certain classes of special bridges, and corresponding
design approaches. From this, dynamic response modification strategies can
be developed for bridge types.
Technical Challenges
The primary challenge will be in synthesizing bridge-specific
information and assessments into more generic approaches that can be used
for future special bridge studies. |