HomeMy WebLinkAboutTIC 2017-03-28 Item 2D - Presentation - State of the City's Bridgesr LAiy �y� City of Tukwila
Allan Ekberg, Mayor
Public Works Department - Bob Giberson, Director
TO: Transportation and Infrastructure Commi tee
FROM: Bob Giberson, Public Works Director
BY: Steve Carstens, Senior Program Manager
CC: Mayor Ekberg
DATE: March 24, 2017
SUBJECT: Presentation on the State of the City's Bridges
ISSUE
Provide the Transportation and Infrastructure Committee with information about the entire City
bridge inventory and program. This will show the overall condition of the City's bridges as well
as steps we can take for future projects and maintenance.
BACKGROUND
The Federal Highways Administration (FHWA) and Washington State Department of
Transportation (WSDOT) require regularly scheduled inspections of all the City's traffic
carrying bridge structures. The City also extends this effort to its pedestrian bridges. This
requirement allows for continuity in reporting as well as the opportunity to identify and
potentially fund bridges in need of replacement and rehabilitation.
DISCUSSION
The City currently has 23 bridges owned by the City (16 traffic bearing and 7 pedestrian). Of
those, two are jointly owned jurisdictional bridges with shared ownership between the City of
Renton (Grady Way) and the City of Kent (196th/200). The structure types very from Steel
Truss, pre -cast concrete girders, cast -in -place concrete girders, steel girder, wood girder, and
steel tied arch spans. This discussion will focus on why the City inspects its bridges, where
the City stands with respect to the state and the country, and recommendations for additional
steps that can be taken to address known issues.
RECOMMENDATION
Discuss, with the Transportation and Infrastructure Committee, the state of the City's bridge
program and address any issues the committee may have.
Attachments: State of the City's Bridges Presentation
W: \PW Eng \OTHER \Bridge \z - bridge City Eng report\2017 -03 -28 info memo TIC insp rpt sm.docx
6300 Building • 6300 Southcenter Boulevard Suite 100 • Tukwila, WA 98188 • 206 - 433 -0179
Tukwila City Hall • 6200 Southcenter Boulevard • Tukwila, WA 98188 • 206 - 433 -1800 • Website: TukwilaWA.gov
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State of the City's Bridges
Why do we inspect
bridges?
• 1967 Silver Bridge Collapse
• Rush hour Traffic
• 46 people lost their lives
• Prompted 1968 Federal Highway
Act requiring inspection of bridges
and inspector training
NBIS
National Bridge Inspection
Standards
Why do we inspect
bridges?
• Guidelines go back to 1971
• Minimum training hours required
for inspectors
• Creates a consistent standard for
inspectors to meet.
• Ranks bridges from 0 to 100
• Requires inspections to be
performed on a regular basis.
CITY OF TUKWILA
CITY ENGINEER'S BRIDGE INSPECTION REPORT
FEBRUARY 2017
• City Engineer's Bridge Report lists all of the
City's 23 bridges
• Gives reader key information on each
structure
• Lets you know if a bridge is structurally
deficient or functionally obsolete.
• Allows you to gauge the health of the
structure.
• Keeps you and the public informed of the
state of our most expensive assets!
What are the conditions of
our bridges?
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• Structurally Deficient (SD) = If key load carrying elements
are found to be in poor condition (deterioration /damage)
• Functionally Obsolete (FO) = certain items do not meet
current design criteria (geometry, load capacity, clearance,
etc)
• Sufficiency Rating (SR) = way to quantify the structure
using a numbering system. You can also think of it as the
age left before a structure is not able to carry vehicles (or
people).
Quick Definitions
• Number of total Traffic bridges:
• Number of Pedestrian bridges:
• Number of SD bridges:
• Number of FO bridges:
• Average SR:
• Average Age:
• Our Overall Grade =
• WA Average: Percent of SD bridges =
• National average: percent of SD bridges =
*from Transportation for America, 2013
* *from ASCE 2017 Report Card for America's Infrastructure
16
7 (includes TUC Ped Bridge)
3 or (18 %), it will soon be 2, or (13 %)
4 or (25 %)
69.22
37 years (design life = 50 years, service life = 75 years)
C to D (based on grading method from ASCE report)
5 %, Grade = C -*
9 %, Overall grade = C + **
Show me the numbers!
•11111111111111111111 11111/1111
• There are 2 potential candidates for the
Bridge Replacement Advisory
Committee (BRAC) grant which we
would ask permission to submit for:
• 42nd Avenue South Bridge (Tuk #14)
Replacement Candidate
• South Boeing Access Road (over Airport
Way — Tuk #11) Seismic Upgrade
Candidate
BRAC Candidates
42nd Ave South
• SR 19.76 and SD. Built in 1949.
• Paint System is failing
• Structural issues with load carrying ability
—may be required to place load
restrictions on it soon.
• Rehabilitation could run $6 million
(higher maintenance costs)
• Replacement could run $10 - $12 million
(lower maintenance costs). Need to
determine location of new structure
• Costs of either option are paid 80%
federal, 20% city.
• SR 56.50 and SD. Built in 1952.
• Only meets requirement for seismic grant
• Major access route from 1 -5 to major
commercial areas
• Seismic rehabilitation could run $4 million.
Construction costs 100% reimbursed by
Federal Grant. Design costs are 80% federal
share and 20% city.
• No work on deck, limited to substructure.
Therefore limited impact to BAR traffic on
deck.
• Future funding to install sidewalk or repair
Boeing Access over Airport
Way
deck would still be available
• Public Works /Engineering is requesting permission from the Transportation Infrastructure Committee to
submit applications for the 2017 BRAC grant cycle. Specifically:
• Submit an application for the replacement of 42nd Avenue South.
• Submit an application for the seismic upgrade of South Boeing Access Road (over Airport Way).
What are we asking for?
4
Questions?