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Most bridge repair projects deal strictly with the
structure itself and generally the contractor needs vehicle access under the
bridge to perform the work. Even for as simple access as this, a gravel road
is required [to be built] and then must be removed following the work
performed, with [the area] restored to its original condition — no matter
how long or short the project duration. Again, cost comes into play.”Minnesota DOT’s Gary Peterson says that when he
thinks about environmental issues, he thinks about red lead paint issues.
“We don’t use our own forces to repaint bridges that
have red lead paint,” Peterson says, “but we do regularly use contractors to
do that work. Our inspection staff certainly has more work to do to track
and document waste removals.”
In Wisconsin, DOT State Bridge Engineer Stan Woods
says his agency has minimized the problems with [environmental issues] by
clearly defining what they are when scooping the project.
“We have to deal with fish habitat, backwater
issues, and erosion control to name a few,” Woods reports. “However, these
are reasonably well defined and early contact with our DNR for any special
issues allows a smooth transition to bridge construction. Occasionally, we
hit a snag through lack of communication or common sense being applied or
construction time being too tight to work around the spawning season.”
Slowed projects and increased costs such as these
are common complaints among the bridge engineers surveyed.
Environmental restrictions and their added costs
have reduced the number of bridges replaced in North Carolina, says DOT
Bridge Maintenance Engineer John Emerson.
The way restrictions sometimes limit construction
time can be a problem, too, says Delaware DOT Bridge Maintenance Engineer
Douglas Finney.
“Environmental processes increase the time required
to design and clear projects,” says Wyoming DOT State Bridge Engineer Gregg
Fredrick.
Environmental restrictions and funding woes meld for
some.
“It’s costing more to be environmentally aware,”
says Tracy Painter, bridge inventory and inspection engineer at the South
Dakota DOT. “This funding is being taken from the bridge replacement funds.”
Finding money
This year, as last, 100% of bridge engineers
surveyed cite funding as their greatest challenge in reducing the number of
deficient bridges.
Even though they see lack of money as the challenge,
only a few have ideas about how to solve the problem.
Texas made a move this year by revising local
requirements to allow 100% federal/state funding of a TxDOT-programmed
bridge when local government agrees to perform structural improvement work
on other deficient bridges with a dollar amount equal to their normal match,
according to TxDOT’s Mike O’Toole. Texas has a goal that 80% of their
bridges will be in good or better condition by 2011 and no state bridges
will be structurally deficient.
Finding the right staff and the money to hire them
is part of the funding challenge at Caltrans, according to Michael Johnson,
office chief.
In Kansas, the large number of bridges built in the
50s and 60s lie behind many of their bridge funding woes. As these bridges
reach the end of their design life, they need significant funding to keep
up, says Dan Scherschligt, Kansas DOT bridge management engineer.
Slow and steady is the Missouri DOT plan. The agency
has an allowance in its transportation improvement plan to address deficient
state-system bridges, says Bridge Structural Service Engineer Mike Harms.
The results show — with steadily decreasing deficient state and non-state
bridges over the past several years.
Funding for county bridges is a challenge for the
Indiana DOT, as well as for most states. Bridge Inspection Engineer Bill
Dittrich says that many aging local bridges carry more and heavier traffic
than they were designed to handle, yet no funding solution seems to be in
sight.
Better management of bridge funds and data can help
solve funding challenges according to Steve Anderson in the Bridge Division
of the Nebraska Department of Roads.
The New Mexico state legislature passed a bill
generating new revenue and providing bond authority for a major construction
program says State Bridge Management Engineer Steve Quintana.
Problem roots
Corrosion causes the most bridge damage, with 65% of
those surveyed citing it. Age of the bridge wasn’t far behind — mentioned by
61%.
More — and heavier — traffic than slated for bridge
designs were major problem factors as well.
In Louisiana, DOT Engineering Technician Ray
Mumphrey says that “In some cases, some of the earlier vintage bridges had
some details that may cause maintenance issues as the bridges age.
“As technology improved and we gained more
experience with these details, this problem became less significant. One
example is the concrete deck bridge. This type of structure is a monolithic
cast-in-place girder bridge. It had a detail at the bearing that caused
cracking in the ends of the girder. This cracking reduced the bearing area
and then resulted in spalling of the cap. Other than this detail, the
[design] was a good bridge,” Mumphrey says.
Lack of preventive maintenance adds to age,
corrosion, and heavy traffic damage, says Minnesota DOT’s Gary Peterson.
“Age, corrosion, and more traffic contribute to the
deterioration of our bridges,” reports Wyoming DOT State Bridge Engineer
Gregg Fredrick. “Besides just an increase in traffic numbers, the number of
overweight vehicles crossing our bridges has greatly increased and
undoubtedly contributed to their rate of deterioration.”
Freeze-thaw cycles and salting damage bridges as
well as roads, reminds Pennsylvania DOT’s Dean Schreiber. These problems add
to maintenance needs and funding.
In Tennessee, structural steel and rebar corrosion
are the major source of bridge damage according to DOT Civil Engineering
Manager 2 Wayne Seger. Newer coated products used in current corrosion could
help relieve this problem.
Changes wanted
If wishes were reality, what one aspect of their
bridge program would they change, we asked those surveyed.
In West Virginia, DOT Director of the Maintenance
Division Julian Ware wants more money for routine maintenance, which would
help reduce the deterioration rate of bridges.
Nevada DOT Bridge Design Engineer Marc Grunert also
wants more routine maintenance — to prevent small problems from becoming
large ones.
New funding is the need in Kansas warns DOT Bridge
management Engineer Dan Scherschligt. “We’ve been fortunate to have
back-to-back programs...the second program ends in 2009 [when] we will have
significant bonding debt to repay. Without new funding, starting in 2010,
the gains we’ve made could be quickly lost.”
Minnesota DOT’s Gary Peterson wants increased
preventive maintenance to slow the rate of bridge deterioration. PM can
extend structural life, he says.
Arkansas’ Bridge Engineer Charles Brand wants to
develop a preventive maintenance in the State Highway Transportation
Department for this same reason.
In Georgia, Brian Summers would like to see better
project delivery, replacing more bridges faster.
Additional staff for inspection and maintenance at
the district and state levels heads the wish list of New Mexico’s Steve
Quintana.
“Expenditure of available funding based on bridge
needs” is what Wyoming’s Gregg Fredrick would like. “Our current program is
largely driven by pavement needs,” he says.
Reprinted from Better Roads Magazine
November 2004 |
