Training Update
by Candice Jackson
Ensuring the Integrity of Bridges
In April 1987, a catastrophic failure of the Schoharie
Creek bridge on the New York State Thruway caused 10 deaths. The bridge's
collapse was partially attributed to the effects of bridge scour, damage caused
by sediment carried by swiftly moving water abrading the bridge's abutments or
piers. Today, scour continues to compromise the integrity of the Nation's
bridges, even as engineers and inspectors work to analyze and address potential
problems and minimize the effects. To equip engineers with the latest knowledge
on this subject, the National Highway Institute (NHI) offers course 135046
Stream Stability and Scour at Highway Bridges.
Changes to Federal Guidance
Material covered in this course is primarily drawn from
two Hydraulic Engineering Circulars (HEC) published by the Federal Highway
Administration (FHWA): Evaluating Scour at Bridges, 5th Edition (HEC-18), and Stream Stability at Highway Structures, 4th Edition (HEC-20),
both updated in 2012. Since 2001, FHWA and the
Transportation Research Board have sponsored various research projects
resulting in new guidance for bridge owners and engineers. NHI recently
revamped course 135046 to reflect the latest updates to the circulars.
"Participants learn and
apply the most recent research, deployment, and policy approaches related
to scour," says Joseph Krolak, Hydraulics and Geotechnical team leader for
FHWA's Office of Bridge Technology. "Incorporating risk-based, data-driven
ideas from the scour program aligns the course with important concepts recently
enacted within MAP-21 that we hope will allow safer, more cost effective and
focused designs and analyses."
The 3-day, instructor-led
training presents lessons on stream and stability factors, as well as
preventive techniques for identifying, analyzing, and calculating various
hydraulic factors that affect bridge stability. In addition to the standard
course curriculum, hosting organizations can select three lessons from a list
of eight optional ones: Effects of Debris on Pier Scour, Quantitative
Techniques for Channel Stability Analysis, Abutment Scour Problem Session,
Complex Pier Scour, FDOT Pier Scour Methodology, Quantitative Techniques for
Degradation Analysis, Channel Stability Processes in Gravel-Bed Rivers, and
Techniques for Evaluating Pier Scour in Erodible Rock.
Before each session, instructors contact the host
organization to complete a pre-course questionnaire to determine which three
optional lessons will be taught. These options ensure that each session meets
the specific training needs of the host organization.
Facilitating Participant
Engagement
Instructors present
the course content using a variety of methods, enabling participants to
incorporate the information presented into activities drawn from situations
they would encounter in the field. In addition, the course features an
interactive technology that enables participants to anonymously answer
questions raised by the instructor.
"The answers are visible to the entire class, but identities
of those who answered are not," says Dr. Peter Lagasse of Ayres Associates, one
of the course instructors. "This enables instructors to monitor whether the
concepts are being absorbed and understood, while ensuring that participants
are comfortable enough to share their answers."
At the conclusion of the course, participants
work in groups during a 2-3 hour workshop. Each group applies the qualitative
and quantitative analyses they learned to a real-world scenario to determine if
a Scour Plan of Action is required to remedy the situation described in the
scenario.
This training is ideal for hydraulic, structural, and
geotechnical engineers responsible for assessing possible hydraulic-related
problems and maintaining the integrity of highway bridges. Although the course
is intended for engineers, bridge inspectors and consultants who perform bridge
engineering work also will benefit.
Recommended Prerequisites
NHI offers several Web-based trainings in the hydraulics
program, which participants are strongly encouraged to complete before
enrolling in this course. These include 135091 Basic Hydraulic Principles
Review, 135086 Stream Stability Factors and Concepts, and 135087 Scour at
Highway Bridges: Concepts and Definitions.
"Transportation
professionals are busy, so these Web-based trainings are available online to
minimize their time away from the office," says Louisa Ward, a training program
manager with NHI. "Understanding the concepts covered in these Web-based
sessions will help participants absorb the information presented in course
135046 Stream Stability and Scour at Highway Bridges, and ensure that they get
the maximum benefit from the training."
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| Construction of this bridge on Interstate 35W in
Minneapolis, MN, involved investigating the potential
effects of scour on the foundation. |
Candice Jackson is a contractor for NHI.
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