1

Bridge Inspection General

In the 2020 MnDOT Bridge Inspection Seminars, the afternoon session for Program Adminis-

trators focused on a SIMS tutorial and a Bridge Inspection Program Administrator Checklist

(PDF). Another thorough resource to supplement the PA checklist is the Bridge and Structure

Inspection Program Manual (BSIPM) (PDF). Also, at the PA session a presentation on “Stuff

You Should Now” as a PA was delivered. We would encourage all designated PA’s to revisit

this presentation and other available PA materials and resources before each new inspection

season to assure your local bridge inspection program remains fully compliant from year to

year. But always remember MnDOT staff in the Bridge Inventory Management Unit and

Bridge Inspection Unit, along with State Aid Bridge and your DSAE are available to advise and

to help you through situations that can obstruct or distract your efforts to fulfill the NBIS

regulations. And, our friendly FHWA Bridge Engineer, Tim Anderson is your key resource with

related NBIS matters and other FHWA Bridge programs. Tim’s contact information can be

found on the FHWA Minnesota Division Staff Directory webpage. Tim works closely with the

Bridge Office and State Aid to assure there’s a path to keep the local bridge program growing

while meeting federal regulations.

We’re also very excited to add additional local bridge inspection resources to bolster the

needed support for local bridge owners. We have placed an article under “Routine Local

Bridge Safety Inspection Assistance Update” in this State Aid Bridge News, detailing the who,

what, and when on these new SA Regional Team Leader positions. In the 2021 Bridge Inspec-

tion Seminars, these positions will likely be discussed and further disclosed. Other important

topics in the virtual 2021 seminars will include: fatigue detail screening and inspection, and

we have placed an article on “Fatigue Study Update” in this newsletter as well. The seminar

will also cover pile and pier cap inspection, with a heavy focus on CIP and Steel pile corro-

sion. Because steel pile corrosion is a hot topic in the local bridge world, we have also placed

an article entitled “Pile Corrosion Update” in this newsletter too. We are developing and

instituting additional pile corrosion protection policies for the LRFD Bridge Design Manual

and other MnDOT resource manuals.

Please reference MnDOT’s Bridge Inspection webpage for your training and certification

needs. The 2021 Bridge Safety Inspection Refresher Training Live Online registration infor-

mation can be accessed at https://mnscu.rschooltoday.com/public/getclass/

category_id/896/program_id/49/subcategory_id/3622.

Note, under the Bridge Inspection General topic, we typically discuss opportunities for train-

ing, PA and TL responsibilities, and other related hot topics to understand and overcome.

However, we thought it was timely to give you a recent representative example of great

teamwork on Wilkin County Bridge 84508 involving Brian Noetzelman, Wilkin County Engi-

neer, the MnDOT Bridge Office Fracture Critical (FC) Bridge Inspection Staff, the Steel Fabri-

cation Methods Engineer, the State Bridge Construction Engineer, SA Bridge, and MnDOT D4.

(continue on page 2)

State Aid

Bridge News January 2021

(Carrolton Township Bridge 23536, Heron Rd. over the South Branch of

the Root River, Fillmore County, Minnesota, a winner of the 2019

MnDOT - AGC Bridge Construction Awards.)

Contents:

• Bridge Inspection General (pg. 1-2)

• Fatigue Study Update (pg. 2-3)

• Bridge Maintenance (pg. 3-4)

• Bridge Hydraulic News (pg. 4-5)

• MCEA County Engineers Bridge Committee Update (pg. 5-6)

• Local BRIM Update (pg. 6)

• 2020 Featured Local Bridge Projects (pg. 7)

• Local Historic Bridge Update, Kern Bridge (pg. 8 )

• Major Local Bridge Projects Update (pg. 9)

• Local Timber Bridge Update (pg. 10)

• Quality Plan Process (pg. 10-11)

• Pile Corrosion Update (pg. 11-12)

• Bridge Standards Update (pg. 12-13)

• Routine Local Bridge Safety Inspection Assistance Update (pg. 13-14)

• Local Standard Bridge Plans Update (pg. 14)

• Rural Bridge Project (pg. 15)

• Local Bridge Replacement Program (pg. 15-16)

• Bridge Cost Update (pg. 16)

• Load Rating and Permitting Update (pg. 17-18)

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...continued, Bridge Inspection General

Back in late October 2020, during the pin and hanger assembly inspection for Bridge 84508, we discovered multiple fatigue induced cracks at sever-

al steel girder-diaphragm connection locations. The inspection photos were further evaluated by the Bridge Office, and it became apparent these

connections exhibited classic fatigue prone details and steel cracking. To safeguard against future fatigue crack propagations into the main steel

girders, a remedial repair plan was crafted and communicated with Brian Noetzelman, MnDOT D4, and the Bridge Office. This plan includes MnDOT

D4 assistance with the repairs (e.g. drilling crack arrestor holes), and a future inspection plan to revisit these locations and other fatigue prone de-

tail areas more often. The more frequent inspection effort will be supported by the FC Bridge Inspection staff with snooper and snooper operator

needs under the Master Partnership Agreement with Wilkin County. To keep Wilkin County’s Team Leader well involved in the inspection process,

they will be working along side MnDOT in the snooper bucket. The main point here, it takes good teamwork and collaboration with multiple part-

ners involved to overcome the many challenges we all face with local bridge inspection work. We’re also very fortunate to have excellent and well-

trained local bridge consultant support in the local bridge inspection arena.

Fatigue Study Update

We are happy to report the Local Bridge Fatigue Detail Study has been completed by Collins Engineers Inc. In our 2019 State Aid Bridge News (PDF) we

placed an article on the fatigue study, see pages 12-13. To briefly recap the purpose of the study, in coordination with the County Engineers Bridge Com-

mittee, we wanted to have Minnesota’s steel local bridges inventoried for fatigue prone details. We agreed that susceptible locally owned bridges

should be inventoried for fatigue prone details and tracked for potential steel cracking.

We have posted a short PowerPoint presentation

on the Fatigue Detail Study and the Final Study

Report on the State Aid Bridge Resources

webpage. We look forward to presenting the

PowerPoint live someday at future State Aid

district meetings. Until then, you can hear all

about steel fatigue details from Peter Wilson,

MnDOT’s Fracture Critical Team Leader Specialist,

at the virtual 2021 Bridge Safety Inspection Re-

fresher Training Sessions in February and March

2021. Registration and information can be found

at https://mnscu.rschooltoday.com/public/

getclass/category_id/896/program_id/49/

subcategory_id/3622.

(continue on page 3)

Wilkin County Bridge (Bridge 84508) CSAH 33 over the Red River of the North near the City of Wolverton. Constructed in 1974, the bridge consists of three spans with six rolled steel girders and twelve pin & hanger assemblies. During the scheduled 2020 MnDOT pin and hanger assembly inspection, fatigue cracks were discovered in several steel girder diaphragm connections. MnDOT D4, Wilkin County, and the Bridge Office developed a structural repair plan to arrest cracks and soften the connection details.

Chapter B – Bridge Inspection Field Manual

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...continued, Fatigue Study Update

Regarding the Local Bridge Fatigue Detail Study Final Report, here are a few tidbits about the report findings. We have approximately 1,400

local bridges on the inventory that have steel beam or truss superstructures. Recognizing a majority of these bridges will have steel fatigue

prone details with no potential issues or with a low frequency of crack occurrence and a low consequence of cracking, the study incorporated a

screening process to narrow down the bridge list. The screening process included factors, such as ADT to account for consequence and likeli-

hood of fatigue. Also, the year built was considered in the screening process. We know around 1986 the AASHTO bridge design specifications

incorporated practical procedures to more accurately reflect the actual fatigue conditions in steel bridges.

The screening process resulted in approximately 150 local bridges to be evaluated and ranked for steel fatigue details. Collins Engineers Inc.

developed fatigue detail reporting forms for each bridge listed in the Final Study Report. The forms identify the fatigue details present on the

bridge, the fatigue prone detail rank in order from 1 to 4, with 1 representing the least potential for performance problems or failure, and 4 rep-

resenting the most. The forms also include the total fatigue bridge rank which is the summation of the individual fatigue detail ranks. It’s most

useful for the purpose of identifying those bridges with multiple problematic fatigue details.

Please note, the data on the fatigue detail reporting forms has been uploaded into the SIMS (Structure Information Management Sys-

tem) SIA (Structural Inventory and Appraisal) One Column (steel fatigue data) form. Also, the BIMU (Bridge Inventory Management Unit)

will add a Steel Cracking (element #882) to the bridge inspection report for the 2021 inspection year. This added element will need to be

properly evaluated and coded per the MnDOT Bridge Inspection Field Manual and the Bridge and Structure Inspection Program Manual

(BSIPM) (PDF) . Lastly, even though we performed a statewide local bridge fatigue detail study, there could potentially be additional lo-

cal bridges with fatigue prone details that have performance problems. The Team Leader is still responsible to review the entire bridge

for any fatigue prone details per the BSIPM, see pages B-170-171, and D-187-227.

Bridge Maintenance

Training

Bridge Maintenance Training is available to local agency participants. Training announcements are posted on the MnDOT Bridge and Structures

Training webpage.

Bridge Maintenance Academy I

MnDOT is converting Bridge Maintenance Academy I into eLearning modules. Modules will be posted on the MnDOT Bridge and Structures

Training webpage as they become available. It is anticipated that the Bridge Plan Reading eLearning Module will be available by Spring 2021.

Bridge Maintenance Academy II and III will not be offered in 2021 due to public health precautions pertaining to COVID-19/Coronavirus.

Anticipated future course dates are:

• Bridge Maintenance Academy II – February 2022

• Bridge Maintenance Academy III – February 2023

Bridge Preventive Maintenance eLearning Modules

Bridge preventive maintenance eLearning modules developed by MnDOT are available to local agency participants at no cost on the MnDOT

Bridge and Structures Training webpage.

The eLearning modules focus on planning, equipment, materials and best practices for the following bridge maintenance activities:

• Crack Sealing

• Strip Seal Gland Repair

• Poured Joint Sealing

• Bridge Flushing

Bridge Maintenance Manual

The Bridge Maintenance Manual is posted on the MnDOT Bridges and Structures Bridge Maintenance Manual webpage.

(continue on page 4)

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...continued, Bridge Maintenance

Structure Information Management System (SIMS) Maintenance Module

The SIMS Maintenance Module is available for local agencies to track maintenance needs and accomplishments per bridge. If interested, please

contact Sarah Sondag at sarah.sondag@state.mn.us to schedule a demonstration.

AASHTO TSP2 Midwest Bridge Preservation Partnership

The AASHTO TSP2 Midwest Bridge Preservation Partnership (MWBPP) is comprised of representatives from regional state and local highway agencies, provincial transport agencies, industry, suppliers, consultants, and academia. The mission of the partnership is to provide a platform for the MWBPP Member Agencies and Organizations to exchange, promote, and advance best practices, new technologies, and innovation in the areas of highway bridge management, inspections, preservation, and maintenance. One of the goals of the MWBPP is to promote outreach to local agencies. The partnership has monthly teleconference calls, working groups and regional meetings in order to conduct partnership business and exchange bridge preservation knowledge. In 2019, the partnership adopted the following language regarding Local Agency Participation into the bylaws: Local Agencies may join a regional partnership upon payment of a membership fee of $2,250 each year. The local agency member would then be allowed full participation in the Regional Partnership for either bridge or pavement preservation and would have travel expense reimbursement for one person per local agency membership. The Regional Bridge Preservation Partnerships collaborated in 2020 to offer a series of webinar topics: • Bridge Deck Preservation Using Overlays • Bridge Preservation by Eliminating Bridge Joints • Impact of COVID-19 and Budget Restrictions on Bridge Inspection and Preservation Programs • Bridge Preservation Using Preventive Maintenance/On-Demand Contracts • Local Agency Bridge Preservation • Preventing Corrosion of Steel Bridges • Repairing Cracked/Damaged Steel Bridges • Bridge Deck Preservation Using Sealers Video recordings of the webinars are available on YouTube at http://bit.ly/2020BridgeWebinars. It is anticipated that the 2021 Midwest Bridge Preservation Partnership Regional Meeting will be held in Lexington, KY September 28 – 30, 2021. More information about the MWBPP is available at https://tsp2bridge.pavementpreservation.org/midwest-mwbpp/. If you have any questions regarding bridge maintenance, please contact Sarah Sondag at 651-366-4529 or sarah.sondag@state.mn.us.

Bridge Hydraulic News

Greetings from your friendly State Aid Bridge Hydraulics Engineer!

2020 saw a couple of MnDOT Technical Memorandum updates that are of interest to local agencies. Tech Memo 20-09-B-03 (PDF) renews guid-

ance on applicable methods of hydrology and utilization of Atlas 14 precipitation values. Tech Memo 20-05-B-01 (PDF) updates the minimum

cover and maximum fill height tables used for design of reinforced concrete pipe sewers.

If you have any bridges with scour plans of action now is a good time of year to go through them and be sure everything is up to date and rele-

vant. Verify if your monitoring plans still make sense, is the detour route still applicable, etc. For more information on bridge scour, visit the Hy-

draulics Bridge scour webpage. You may also reach out to me if you have any questions or comments, Erik Brenna, State Aid Hydraulics Engi-

neer at erik.brenna@state.mn.us or 651-366-4536.

The U of M rolled out the virtual Aquatic Organism Passage (AOP) training in the fall. This course was developed around the Minnesota Guide

for Stream Connectivity and Aquatic Organism Passage Through Culverts (PDF). The guide was jointly funded by MnDOT and the Local Road

Research Board (LRRB). Most of the sessions have filled up but there is a waitlist if you are interested in learning more. Visit the U of MN CTSS

X150 - Culvert Design for Stream Connectivity and Aquatic Organism Passage webpage for course content.

All for now, enjoy a couple of pics of an open spandrel arch bridge faithfully tended to by the good citizens of Olmsted County and Oronoco,

MN.

(continue on page 5)

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...continued, Bridge Hydraulic News

MCEA County Engineers Bridge Committee Update

The County Engineer Bridge Committee (CEBC) was busy meeting in 2020 to work through a variety of hot local bridge topics. As always, feel

free to explore past State Aid Bridge News for more details and history on the CEBC, and the important bridge work that flows through the

committee. Also, if you see another need area in the local bridge world, do not hesitate to contact Brian Pogodzinski (Houston County Engineer)

or Dave Conkel (State Aid Bridge Engineer) to get the issue moving through the CEBC.

The CEBC met in June via Zoom to discuss and develop recommendations

for the new Bridge Ownership & Ownership Responsibilities document

Championed by Mark Gieseke, MnDOT Director, Engineering Services Divi-

sion, and Marc Briese, State Aid Programs Engineer. The document,

“Process to Determine Bridge Ownership and Responsibilities,” can be

found on the Resources webpage. Other hot topics scattered amongst our

November - January meetings included: preparing the way for the full tran-

sition from Sufficiency Rating to LPI, entailing revising the bridge inventory

and BRIM reports to solely report LPI scores. Also, State Aid checklists and

related local bridge forms were modified to include LPI.

The CEBC also recommended Program Administrator (PA) training needs

that will be infused into the 2021 Bridge Safety Inspection Refresher Trainings and other future resources. David Hedeen (Asset Management

Engineer) will be presenting a 20 minute PowerPoint to our city engineers in 2021 on PA responsibilities, including topics: NBI, reading bridge

inventory and inspection reports, FHWA 23 Metrics, bridge report forecasting, bridge inspection condition history reporting, important dates,

etc. This same PPT on PA responsibilities was presented at the 2020 Bridge Safety Inspection Refresher Trainings. If you’d like a copy of the

PPT please contact David Conkel at dave.conkel@state.mn.us.

At the recent CEBC meeting on December 30th 2020, we focused on the Timber Hauler Permit Fee Account and developing a final recommen-

dation for the MCEA BOD on permit fee usage towards two new SA Regional Team Leader Bridge Safety Inspection positions, a load posting

sign account, advanced inspection tools, SHV budget increases, a bridge safety inspection training account, and a potential one time fund allo-

cation to MnDOT for the development of their new overweight permitting software called “Super Load.” Brian Pogodzinski, CEBC Chairman,

has met several times in 2020 with the MCEA BOD regarding the timber hauler account to support local bridge safety inspection needs as re-

quired by MN state statutes. Both Brian Pogodzinski (Houston County Engineer) and Rich Heilman (Isanti County Engineer) and CEBC member

will be bringing the CEBC final recommendations to the MCEA BOD in January 2021.

(continue on page 6)

Bridge No. 448 over the Middle Fork Zumbro River and Lake Shady dam in Oronoco, MN circa 1962.

Bridge No. 448 over the Middle Fork Zumbro River and remains of Lake Shady dam in Oronoco, MN circa 2020.

It was a Zoom Zoom and away year for the Minnesota CEBC

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...continued, MCEA County Engineers Bridge Committee Update

At the CEBC meeting there’s always ample time to allow Dave Conkel (State Aid Bridge Engineer), Moises Dimaculangan (State Aid Load Rating

& Permitting Engineer), Brian Homan (State Aid Bridge Plans Engineer), and Patti Loken (State Aid Program Support Engineer) to give other

bridge topic/fund updates. It was a very interesting year for local bridge construction. We had a deck form collapse, concrete forming and steel

bridge rail fit-up issues in Nicollet County, as well as an abutment form blowout, and a multitude of pier concrete caisson construction issues

(too many to list) in Redwood County. A timber bridge was vandalized and set on fire in Ottertail County. We had some sloppy precast concrete

box culvert and prestressed concrete beam fabrications. Also, several counties experienced poor precast concrete box culvert installations, and

poor bridge deck and sidewalk ride and finishing issues.

We’re sure there’s more, but in all cases the county engineer and county inspection staff, with support from State Aid Bridge, county’s local

bridge consultant, and the MnDOT Bridge Office, overcame the many local bridge challenges during 2020. Hats off to Seth Greenwood (Nicollet

County Engineer), Al Forsberg (Redwood County, CSAH 101 Bridge Project Engineer), Chuck Grotte (Otter Tail County Engineer), Joe Macpher-

son (Anoka County Engineer), Rachel Gregg (St. Louis County Bridge Engineer), Ron Gregg (Fillmore County Engineer), etc. doing excellent

work out there and supporting the necessary team effort to assure successful local bridge projects.

Local BRIM Update

The Local BRIM tool with the LPI criteria for bridge funding took over on January 1, 2020. All local bridge owners should now be using BRIM as a

helpful bridge priority tool and a bridge funding eligibility marker into the future. We’ve placed several articles and associated links on the BRIM

in the past few State Aid Bridge newsletters, see the 2019 State Aid Bridge News (PDF) pages 8-9 and the 2020 State Aid Bridge News, page 6

for a BRIM tool refresher. Please remember State Aid Bridge and the State Aid Office can assist you with any BRIM questions and funding eligi-

bility needs. Specific state aid contacts include Marc Briese, Patti Loken, and Dave Conkel. Also, a very helpful individual of the BRIM tool is Brian

Pogodzinski, Houston County Engineer, County Engineers Bridge Committee Chairman, and Champion of the BRIM.

A quick update on the BRIM includes the following activities—we updated the Excel Local

BRIM Calculator Program to better mesh with the auto generated BRIM report for Locals. The

Excel program had a few minor glitches in the culvert LPI scoring logic. Please remember this

Excel program on the Local BRIM webpage is only a checking tool against the BRIM report

output at https://reports.dot.state.mn.us/bridgereports/FormDefinition.aspx?rID=3228065.

The Excel program can help a local bridge owner better understand how the LPI scores are

auto calculated with the bridge inventory and inspection data. The Excel program requires

the local bridge owner to manually read and enter the bridge data into the Excel program.

This manual process reveals the fine details of the LPI score. It also allows the owner to tweak

input data to see the effects on the LPI score. For example, let’s say we have a township

bridge with a steel beam span with an autogenerated LPI score of 62 which just slightly ex-

ceeds the criteria of LPI less than 60. The owner if they so desire, can manually populate the

Excel program with data such as the NBI conditions ratings for deck, superstructure, substruc-

tures, etc. They can then slightly tweak these NBI condition ratings and other data to see

their effects on the LPI Score. This exercise will give them a better feel on what’s inevitability

needed to become eligible for bridge funds someday based on LPI criteria.

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2020 Featured Local Bridge Projects

The 2020 AGC Bridge Construction Award in the bridges costing less than $1.5 million

category went to Lyon County Bridge 42576 on County Road 83 over the Redwood

River. Congratulations to Lyon County, RR Schroeder Construction and Erickson Engi-

neering for great team work in demonstrating a high quality, timely, and a very aes-

theticly pleasing bridge that fits in beautifully with the historic buildings of Camden

State Park.

What began as a rehab proposal for three 1910’s to 1930’s-era Warren pony truss

bridges turned out to be a set of full structure replacements. The third bridge, Bridge

42576 of the contract, was fully completed in November 2019. The structure type of

Br 42576 was selected once considerations were incorporated from DNR hydrologists,

historians, cultural resources, and resource teams. The proposed structure drew inspi-

ration from an original WPA 1930’s bridge built of concrete, split stone, and timber.

The most unique aspect of the bridge aesthetics is the custom architectural surface

treatments. The contract required a custom form liner finish to match the appearance

of the Camden Park WPA rustic style historic buildings.

Bridge 42576, County Road 83 over the Redwood River, Lyon County. Photo

showing the beautiful three-span continuous slab concrete bridge with architec-

tural treatment, timber rail, and solid piers.

Some complexities of the project included complex work scheduling to minimizing access restrictions to users and park staff along the park’s only access

road. This ultimately entailed construction during a colder and snowier than average winter coupled with ice jams and record spring flooding. Although

the deck pour was a few weeks behind schedule, the remainder of the bridge was completed quickly, and the park was able to fully open to kick off the

summer season. Another challenging aspect of the project included difficult subsurface geology laden with large cobbles and boulders calling for H-piles

with tip protection. Fortunately, the deep foundations were able to be constructed, however strenuously, with standard construction equipment.

Although concrete was poured throughout the winter, it was all of high-quality with no rejected loads or honeycombing. No marks can be recalled

against workmanship or quality control throughout the contract as it was obvious the workers took personal pride in the construction of this prominent

structural element of the park. The bridge railing is straight, posts are plumb, and the form liner joints all but disappear.

The 28th Avenue Bridge over Minnehaha Creek was a formidable 2020 Nomination

for an AGC Bridge Construction Award in the $1.5 million to $5.0 million bridge con-

struction cost category. The bridge is nestled between Lake Hiawatha and a residen-

tial neighborhood in south Minneapolis and boxed in by old growth trees to be re-

tained on the west and overhead power lines on the east. During construction com-

munication utilities needed to remain in service along with water and sewer service to

adjacent homes. These constraints made it difficult to execute work below the ground

surface and to operate cranes and other equipment above the ground surface. To

meet these project challenges, several innovative features were employed.

Such innovative features of the bridge included that concrete bridge construction had

to be above the ordinary water elevation of Minnehaha Creek. This required retaining

portions of the old concrete bridge and drilling new micro pile deep foundation ele-

ments through the old south abutment footing. There were two temporary steel

structures erected to carry communication line utilities over the creek. Also, a tempo-

rary pedestrian bridge was constructed for the winter by using the installed pre-

stressed beams prior to placement of the deck.

Bridge 27C59, 28th Ave over Minnehaha Creek, City of Minneapolis. Photo

showing east fascia of the new bridge.

The city and residents of the neighborhood recognized the at-grade trail crossing associated with the old bridge as a safety hazard to trail users and the

motorized traffic on 28th Avenue. The grade separation of the trail will now greatly improve the safety of the site for trail users.

S.M. Hentges & Sons, Inc., Mike Speedling and Steve Olson of Olson & Nesvold Engineers, and Ahmed Omar of the City of Minneapolis worked closely

together to achieve a successful project.

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Local Historical Bridge Preservation Update

To our amazement, we have been providing an annual local historic bridge preservation update since roughly 2010. Apparently, local historic

bridges are truly a fixture in the statewide local bridge program. We continue to be astonished at the enthusiasm, dedication, and effort by our

local historic bridge owners with our county and city partners to forge ahead with a strong Minnesota Local Historic Bridge Program! Another rich

local historic bridge project in the making, and which exemplifies true commitment to our historic bridge heritage is the Kern Bridge Project. Last

February the mighty 189’ span Kern Bridge over the Le Sueur River in Blue Earth County was delicately removed from its crumbling and deterio-

rating stone abutments. You can recapture this excitement by visiting Highlight Kern Bridge (YouTube) and other excellent documents on the

Kern Bridge.

So many dedicated players made this removal and storage project a great success. Ryan Thilges and Stefan Gantert of Blue Earth County led the

way to assure the project was successful. They retained Joe Litman of LHB Inc. to prepare removal and disassembly plans and to help oversee the

contractor’s removal and disassembly work. Also, State Aid Bridge, D7 State Aid, and State Aid CO helped with funding, plan reviews, and the

necessary coordination work to make the project a reality. A special thanks to Patti Loken (State Aid Program Support Engineer) and Lisa Bigham

(D7 DSAE) for their help and support with this unique local bridge project. The project and rich Kern Bridge History certainly engaged Lisa as she

has been championing the Kern Bridge solicitation for relocation effort as well!

Here’s a little on the Kern Bridge solicitation for relocation effort. A Kern Bridge solicitation for relocation memo was announced back in July 2020.

The memo provided some relevant background on the Kern Bridge, the available federal funds to reconstruct the Kern Bridge for pedestrian us-

age at a new location and to rehabilitate it to the Secretary of the Interior’s Standards, and to revise the National Register of Historic Places listing.

It discusses the local match and federal program requirements, timeframe and deliverability information, a timeline guidance document for pro-

ject development to construction, and a solicitation schedule listing the LOI (Letter of Intent) deadline, full application deadline, etc. The Kern

Bridge solicitation for relocation memo can be viewed on the Historic Bridge Available Bridges webpage.

Again, to our amazement we had two metro

counties, two outstate counties, and three

outstate cities submit LOI’s. The LOI’s were

carefully reviewed by a Kern Bridge Partners

steering committee consisting of engineers

and historians. Of the seven excellent LOI’s

reviewed, four were selected for a full applica-

tion and a full application review by the steer-

ing committee. The full applications will in-

clude the needed partners, sponsors, local

resolutions, maintenance agreements, cost

shares, etc. The steering committee will be

reviewing the full applications in mid-January

2021, and the successful applicant will be

announced likely in February or sooner. We

all sincerely appreciate the time and effort put forward by all agencies and the steering committee members thus far. It’s been a pleasure review-

ing these excellent candidates for the Kern Bridge. We’re confident the permanent home and agency for the Kern Bridge will be well deserved.

FYI, please visit Historic Bridge Available Bridges webpage to gain more interesting facts and information on the Kern Bridge.

On another historic bridge note, Bob Frame of Mead & Hunt and Katie Haun Schuring, MnDOT CRU Historian, are working on an historic bridge/

tunnel survey update to address bridges/tunnels built between 1970 and the early 1990s. At the suggestion of State Aid Bridge, Bob will be reach-

ing out to several county and city engineers, MnDOT past and present bridge engineers and our local bridge consultants engaged in bridge-related

activities during this study period. Several survey questions Bob will introduce include: briefly characterize your professional work with bridges

during this period, do you recall any innovations in terms of bridge types, design details, or materials from the period, what bridges built in Minne-

sota during this period stand out to you as important, why would you consider them important, etc. If you want to partake in this study, let us

know ASAP. Dave Conkel, State Aid Bridge Engineer, consulted with Bob Frame and indicated he started his bridge career at HNTB in 1986 and

worked on the Hennepin Ave Suspension Bridge, and the Hwy. 61 Lafayette Bluff Tunnel, the first mined hard rock highway tunnel in Minnesota,

to name a few.

Bridge L5669, Historic Kern Bridge being strategically disassembled in March 2020, photo courtesy Blue Earth County

9

Major Local Bridge Projects Update

We have two monster local bridge projects from the City of St Paul in the hopper to coordinate, review and process through State Aid Bridge.

The bridge projects include the Eastbound Kellogg Boulevard Bridge Replacement and the Kellogg Boulevard/3rd Street Bridge Replacement.

The EB Kellogg Blvd. Bridge comes with an estimated project cost of $30 million and a fall 2021 letting date. The Kellogg Blvd./3rd Street Bridge

checks in with an estimated project cost of $66 million and a spring 2022 letting. As you may recall, in late October 2020 the Governor signed a

bonding bill into law which included $52 million for the Kellogg Blvd./3rd Street Bridge. The bridge consultants on board to tackle these challeng-

ing bridge projects for St Paul, include TKDA with Matt Christensen serving as the PM for the EB Kellogg Blvd. Bridge, and SRF Consulting Group

Inc. with Jamison Beisswenger serving as the PM for the Kellogg Blvd./3rd Street Bridge. The St Paul Bridge Engineers overseeing these projects

include: Dag Dejene, Brent Christensen, and Glenn Pagel.

Here’s a little background information on the

EB Kellogg Blvd. Bridge. It involves a multi

level intertwinement of tunnel structures in

sandstone and bridge structures under EB

Kellogg Blvd, nestled between the Saint Paul

RiverCentre and the RiverCentre Parking

Ramp and the Science Museum. There is the

existing St. Paul RiverCentre Skyway which

crosses over the project site to connect the

parking garages to the RiverCentre. The Sky-

way has a center pier foundation located

above the proposed RiverCentre and Xcel

Energy Center loading dock tunnel. This situ-

ation along with many other geotechnical and

structural engineering challenges make this

project very complicated. In order to visualize

the proposed and existing structures to deter-

mine plan and staging conflicts, 3D models are being employed. Leave it to TKDA and Matt Christensen, and their geotechnical subconsultant

CNA Consulting Engineers to think innovatively to develop a cost effective bridge and tunnel layout system. The preferred layout will best serve

a staged construction approach to keep the RiverCentre and Xcel Energy Center loading dock tunnel system in service throughout construction,

and to minimize traffic disruptions and provide a safe project site.

Regarding the Kellogg Blvd./3rd Street Bridge, this project entails replacing the current 20-span prestressed concrete girder bridge that carries

Kellogg Boulevard over the BNSF Railway, UP Railroad, Bruce Vento Nature Sanctuary (BVNS), Commercial Street, and I-94. The bridge is one of

only two connections between downtown and Saint Paul’s East Side. In 2014, MnDOT’s State Aid Bridge Office initiated a load rating of Bridge

62080 and 62080A as part of their local specialized hauling vehicle (SHV) ratings project. Noting signs of distress on the pier caps, the city re-

tained SRF to perform an in-depth inspection and analysis of the structure. Inspection findings (most notably deterioration below leaking expan-

sion joints) coupled with changes to design codes led the city to close the outer lanes of the bridge as the pier cap cantilevers no longer met code

requirements for strength. Since 2014, traffic on the bridge has been restricted to the three innermost lanes with a narrow six-foot lane shared by

bicycles and pedestrians. Following the restrictions on the bridge, the city undertook a process to determine whether to rehabilitate or replace

the bridge. Ultimately, due to the need for a more reliable connection to the city that would accommodate vehicular, bicycle, pedestrian, and

transit transportation modes, the decision was made to replace the

bridge.

SRF performed a concept development study for the reconstruction of

the existing bridge. The study took a comprehensive look at all the is-

sues and options and it developed a preferred concept. During the

study, a preferred cross-section consisting of four traffic lanes and two

12-foot trails was identified. To meet the city’s goals of a durable, low-

maintenance structure that maximized the ratio of functionality vs.

cost, a prestressed concrete girder bridge was selected. The selected

bridge configuration is a 12-span prestressed concrete girder bridge

using MnDOT’s MW96 girders (maximum span of 192.5’). The bridge

will be approximately 2,117 feet long. The current project schedule calls

for bridge preliminary plans by April 2021, and final bridge plans,

specifications and engineer’s cost estimate by December 2021.

Bridge 90378, Eastbound Kellogg Boulevard over Exchange Street, Xcel Energy Center and the Saint Paul RiverCentre loading dock,

City of St Paul.

Bridge 62080 & 62080A Kellogg Blvd over RR, Commercial St., and I-94, City of St Paul

10

Local Timber Bridge Update

We have been giving State Aid Bridge News local timber bridge updates whether it be regarding research, inspection, inspection tools, MnDOT

bridge design manual updates, or just successful timber bridge projects, since around 2010. You can enjoy these local timber bridge articles by

visiting the State Aid Bridge News webpage where our newsletters are cataloged by month/year and content.

In this year’s timber bridge update we wanted to finally say the LRRB Development of Cost-Competitive Timber Bridge Designs for Long-Term

Performance is officially completed and posted at https://researchprojects.dot.state.mn.us/projectpages/pages/lrrbProjectDetails.jsf?

id=14742&type=CONTRACT&jftfdi=&jffi=lrrbProjectDetails%3Fid%3D14742%26type%3DCONTRACT! A special thank you to our friendly USDA

Forest Service Engineers Brian Brashaw and James Wacker, and their team of supporting investigators and technical advisory panel members

including Joe Litman - LHB, Inc., David Clemens and Ron Dokken – Wheeler Consolidated, Ron Benson - Stonebrooke Engineering, Inc., Bruce

Hasbargen – Beltrami County, Matt Smith – Laminated Concepts, Inc., Tim Stahl - Jackson County, Dustin Imholte – Bell Structural Systems, and

Travis Hosteng – Iowa State University. We also received excellent administrative support from Donald Fosnacht – University of Minnesota

Duluth.

Within this research effort two separate local timber bridge

demonstration projects ensued. One in St Louis County, and

one in Hennepin County. So, another special thanks to Matt

Hemmila and Steve Bergerson - St Louis County, and John

Ekola, Ned Miller and Amanda Shotton – Hennepin County for

their great work and assistance with the demonstration pro-

jects. If we missed anybody, all the cooperators, TAP members,

and project team are listed in the final report. So, what’s next

for local timber bridge research? To be honest, there’s nothing

coming down the pike in the near future, but we’re certainly still

engaged in local timber bridge related work.

We’re currently developing MnDOT standard bridge details for

crash test level 2 & 4 timber bridge rails for treated timber slabs

and concrete slabs. We discuss this effort in more detail under

the Bridge Standards Update article in this newsletter. As you

can tell, our local bridge consultants and owners continue to

design and build timber bridges. Both Itasca County and Watonwan County recently constructed a timber bridge. Both Jackson County and Beltra-

mi County have planned for two new timber bridges and they are in various phases of design.

Timber Bridge 31580, Itasca Township, Phillips Rd over Split Hand Creek, opened to traffic on

November 5th, 2020.

Quality Plan Process

Back in November 2020, SALT published their new Federal and State Aid Plan Review Checklists on the Plan, Design & Preparations Forms

webpage. These new documents bring better clarity to what is required for project development. They include some general information on

bridges, such as bridge funding eligibility information, pertinent State Aid Rules, GP&E and bridge survey sheet review items, and accompanying

material requirements e.g. signed bridge load rating forms, BrR (Virtis) input files, and signed culvert load rating forms. But the main bridge item

to checkoff is the SBE (State Bridge Engineer) Signature. The SBE signature indicates the local bridge consultant has applied their quality

management plan in all phases of bridge design and plan preparation. In order to assure our Local Bridge Consultants and State Aid Bridge staff

are working together to assure all reviews and QC/QA items are accounted for in the process, State Aid Bridge is developing a new checklist titled,

STATE AID BRIDGE CONSULTANT DESIGN SUBMITTAL CHECKLIST.

Stated Aid Bridge started developing this new checklist back in August 2020 and made some good headway until the onslaught of other local

bridge program work. At the time, we also initiated some new preliminary and final design check verification documents along with updated pre-

liminary and final plan review checklists. We’re hopeful to finish these checklist documents by spring 2021 which includes further vetting from the

Bridge Office and our local bridge consultants. On another front, we’re developing a new DQMP (Design Quality Management Plan) Content

Guide for Prefabricated Pedestrian/Bicycle Bridge Fabricators. This document contains guidance for developing a comprehensive DQMP that de-

tails implementation of a quality control and quality assurance program for the design and detailing of pedestrian/bicycle truss type bridge super-

structures. The development of this document is being championed by Brian Homan, State Aid Bridge Plans Engineer. We’re also hopeful this

document will be completed and looked over by the Bridge Office and our Local Bridge Consultants/Fabricators in spring 2021.

(continue on page 11)

11

...continued, Quality Plan Process

Note, back in 2016, we discussed Quality Assurance and Quality Control QA/QC for

Local Bridge Plans, feel free to visit our 2016 State Aid Bridge News (PDF) pages 10-

11. We will restate that we’re very happy to report that the majority of the consult-

ants serving our local bridge owners are still very diligent in making sure their quality

management plan is fully at work when delivering plans and reports for State Aid

Bridge review.

State Aid Bridge thanks the great professionals we have in our Minnesota local bridge consultants, and the great work they have been

accomplishing over the years.

Pile Corrosion Update

Back in 2014 we placed an article on pile corrosion in the State Aid Bridge News (PDF). We developed a short policy on galvanizing steel piles for

pile bent piers in the MnDOT LRFD Bridge Design Manual (BDM). The policy essentially stated to galvanize piles from top of pile to 15 feet below

ground to protect against corrosion for pile bent piers. However, in the MnDOT Standard Construction Specifications under 2452.3 J Coating Steel

H-Piles and Pile Shells, we allowed both painted and galvanized coated steel piles. Over the years we received feedback on the difficulty of

installing galvanized piles to consistently achieve a galvanized coated pile 10 to 15 feet below the ground surface. As you can imagine, pile drive

depths can vary from pile to pile, sometimes significantly. This reality sets up a challenge for the contractor to plan steel pile splice locations, and

the total number of pile sticks to galvanize for the project. Also, with galvanized piles at the splice location, you must mask the galvanized coating

one foot away from the splice to accommodate welding. Realizing this fact, our local bridge consultants and owners have typically opted for the

painted pile option above ground or water surface.

It became apparent we needed additional guidance on pile corrosion protection for our local and state bridge owners. So, we cobbled together

several engineers from the MnDOT Bridge Office, Foundation Office, and State Aid Bridge to form another pile corrosion subcommittee. This

subcommittee has met on several occasions now, and ironically we were in the process of developing a procedure for corrosion assessment of

steel piles when St. Louis County discovered heavy pile corrosion on their CR 825 bridge. This incident definitely justified our work to develop an

enhanced pile corrosion protection policy. It also stimulated our MnDOT bridge inspection staff to further train on inspecting steel pile elements.

Just a few things about the upcoming MnDOT pile corrosion evaluation process. The detailed process will likely reside in the MnDOT Geotechnical

Manual with appropriate references in the MnDOT LRFD BDM. This new evaluation process looks at the pile location (e.g. fully below the water

table), any evidence of organics, chlorides, industrial contamination, etc. It considers factors such as: soil pH (e.g. pH < 4.5, soil is corrosive), resis-

tivity (e.g. resistivity 700 to 2000 ohm-cm, soil is corrosive), and organics (e.g. OC > 1%, soil is corrosive). Depending on the bridge site and soil

properties/characteristics, associated steel pile corrosion mitigation options were developed. Mitigation options include adding sacrificial steel to

the piles (e.g. adding 1/16” steel for a moderately corrosive environment to 1/4” steel thickness for a very corrosive environment). For extremely

corrosive environments, the mitigation may include both sacrificial steel and a protective coating. The subcommittee performed a little cost

analysis between adding sacrificial steel and galvanizing piles. The results of the cost analysis indicated a wash between adding sacrificial steel and

galvanizing piles for a 75-year life in corrosive environments.

Taking it a step further, the pile corrosion subcommittee reached out to our north central region state DOTs to enquire about their in-place

corrosion protection policies. Of the seven state DOTS that responded, none of them test soils for projects. However, there are some locations

and environments where they may do some soil testing. Soil testing for corrosive soils includes pH testing, resistivity testing, and organic testing.

These tests can add another $2,000 plus to a typical local bridge project for geotechnical work. Understanding and realizing some major local

bridge projects could entail large deep foundations requiring tens of thousands of linear feet of steel piling resulting in significant extra bridge

costs by simply adding on 1/8” sacrificial steel to the piles. We recognize these special bridge projects may benefit from a more exhaustive soil

testing program and evaluation. But for the typical local bridge project we’re developing a more abbreviated process to determine pile corrosion

protection needs. A relatively simple steel pile mitigation table indicating pile location and embedment, soil texture, degree of corrosivity (low to

severe), and the corresponding sacrificial steel needed may suffice. Other states have developed similar easy to implement pile corrosion

protection tables. Also, based on the 2015 Local Road Research Board project to develop a series of steel pipe service-life maps for the state of

Minnesota, we have a fairly good understanding of soil texture, resistivity and pH levels statewide. This information along with expertise from our

geotechnical engineers developing the soil reports should help us deduce the degree of corrosion.

(continue on page 12)

12

…continued, Pile Corrosion Update

Note, we have also been considering revisions to our practices regarding piling and protection from corrosion for integral abutment piles. There

is concern that the abutment stem embedment is not adequate to protect the piles from exposure due to fill/riprap settlement, which can lead to

corrosion/section loss problems on the portion of the exposed pile immediately beneath the abutment. The subcommittee is considering a few

approaches to protect against pile corrosion that include an increase in the abutment stem embedment, and sacrificial steel thickness for the

piles.

Heavy pile corrosion found on St. Louis Bridge 93199, CR 825 over Prairie River Bridge 93199, St. Louis County Bridge crew completed new steel pier installation.

Bridge Standards Update

It’s never a dull moment in the MnDOT Bridge Standards Unit. They always seem to have their hands full with either evolving/updating old standard bridge

details or developing new ones. Updating MnDOT’s catalog of standard bridge railings from NCHRP 350 crash test level criteria to MASH crash test level

criteria over the years has been somewhat monumental. Along with updating the bridge railings to MASH criteria, approach guard railing transition detail

standards and approach panel details continue to evolve as well. The Standards Unit works closely with the MwRSF (Midwest Roadside Safety Facility)

part of the University of Nebraska -Lincoln to setup and perform crash tests to MASH criteria on MnDOT bridge rails. Back in September 2020, MwRSF

crash tested MnDOT’s Structural Tube Railing Design T-1, and Concrete Parapet Type P-2 at http://www.dot.state.mn.us/bridge/pdf/cadd/files/

bdetailspart2/pdf/fig7157ea.pdf (PDF) to MASH test level 4. Note, if you observe the isometric view on the tube rail T-1 and parapet type P-2 on MnDOT

standard bridge detail figure 5-397.157 (A), you’ll notice the interesting geometrics to make the approach guardrail and bridge rail MASH crashworthy.

You can also have some fun watching the actual crash tests at https://www.youtube.com/watch?v=q4RNgwSuzlE (mark 2:31) and https://

www.youtube.com/watch?v=rDSXtJd7Epg (mark 4:40).

Speaking of bridge railing, SA Bridge, Wheeler Consolidated, MnDOT Bridge Standards Unit in coordination with the MwRSF, have been developing

MnDOT standard details for test level 2 and test level 4 timber bridge railing to timber slabs and concrete slabs/decks. These MnDOT standards are long

overdue for timber bridge railing. Over the years our local bridge consultants including Wheeler have been replicating the crash tested timber bridge

drawing/details from the 1995 MwRSF Plans for Crash – Tested Bridge Railing for Longitudinal Wood Decks publication. As you can imagine there are lots

of timber pieces and parts, steel nuts and bolts, and associated specifications related to these railing details. Over time State Aid Bridge has accumulated

slight variants of the original 1995 MwRSF railing details in our local timber bridge plans. In order to assure our local timber bridges are all consistently

being supplied with crash tested timber rail details and hardware, new MnDOT standard timber bridge railing details are being developed. State Aid

Bridge and the MnDOT Standards Unit have been through several rounds of reviews and edits with input from Wheeler. The test level 2& 4 details for tim-

ber bridge railing to timber slabs is complete and ready for routing through the Bridge Office Structural Standards Development and Review

Committee and the R&D for final approvals. Special thanks to David Clemens and Ron Dokken of Wheeler for their input and associated detailed reviews.

Other notable items brewing in the Bridge Standards Unit include the development of 18’ and 20’ wide precast concrete box culvert standards.

Unfortunately, the 18’ & 20’ standard culvert spans have taken much longer to develop than anticipated. The Bridge Office finished working out bugs in

the commercial software and are now finalizing which permit vehicles will be used for the standard designs. The best guess for distribution of the new

standards is the summer of 2021, with our fingers crossed. Until then, if you need a special 18’ or 20’ box design please contact State Aid Bridge, and the

Bridge Standards Unit will work with SA Bridge to provide the reinforcement, thickness, and other requirements. Some items near completion and related

to prestressed concrete beams, include new prestressed concrete beam design charts for the MnDOT LRFD Bridge Design Manual using a new maximum

(continue on page 13)

13

…continued, Bridge Standards Update

initial concrete strength of 8.0 ksi (increased from 7.5 ksi), and a new maximum

final concrete strength of 9.5 ksi (increased from 9.0 ksi). These new maximum

concrete strengths were coordinated and approved by our local fabricators.

Our local fabricators are also interested in moving to the use of SCC (self‐

consolidating concrete), but this will require a change in methods for

roughening the top surface of the top flange. One local fabricator has proposed a

ribbed pattern form liner to provide a roughened surface for SCC and tried it out on

a couple of production beams to see how it affects their fabrication process. They

have dealt with Bridge Office concerns to date, but more discussion is needed on

issues raised by the MnDOT Materials and Inspection Personnel. Another local

fabricator said they may want to develop their own method for roughening the top

flange, so the ribbed pattern will not be added to the standard beam sheets at this

time, more to come! Lastly in the prestressed concrete beam world, current

prestressed concrete beam designs incorporate the use of prestressing strand with

a minimum tensile strength of 270 ksi. Some strand suppliers are now producing

strand with a tensile strength of 300 ksi, which can alleviate some issues regarding

stressing in cold weather as well as producing longer span beams! The Bridge and

Materials Offices have been discussing the implementation of 300 ksi strand with local fabricators and hope to have an implementation plan

available relatively soon.

1995, USDA Forest Service - Forest Products Laboratory with USDOT FHWA

Crash-Test Timber Bridge Railing for Longitudinal Wood Decks per AASHTO

Performance Level 1 and NCHRP 350 Test Level 4.

Routine Local Bridge Safety Inspection Assistance Update

In last year’s State Aid Bridge News (PDF), we started the discussion on routine bridge safety inspection assistance for local bridge owners. Many

conversations with the County Engineers Bridge Committee (CEBC), Bridge Office, State Aid CO, and State Aid Bridge have ensued since last year

regarding this important need for local bridge owners. Back in July-August of 2020 our State Aid Deputy Engineer, Chris Kuffner was investigating

Minnesota State Statutes regarding annual Timber Hauler overweight permit fee appropriation. Realizing the state appropriation for these funds

are to include local bridge inspection, and the fact that significant annual funds have been and continue to funnel into this special account, a more

serious expenditure plan has taken place.

The CEBC met multiple times with the MCEA BOD, and State

Aid CO to discuss/recommend an expenditure plan for these

funds which heavily include statewide routine local bridge

safety inspection support for local bridge owners. Other sup-

port items include bolstering the Special Hauling Vehicle Load

Rating Program, and a Load Posting Signing Account. The

CEBC will be meeting with the MCEA BOD with final recom-

mendations on the usage of the Timber Hauler Fees per Mn

State Statutes on January 19, 2021. The recommendations will

call for two new State Aid Regional Team Leader Specialists

solely to provide the needed support to help sustain and im-

prove the local bridge safety inspection program.

These new State Aid positions will work for local bridge own-

ers and provide that vital link between local bridge owner and the FHWA and Bridge Office. These positions will wear the “State Aid Cap” and help

local bridge owners and their inspection staff to consistently fulfill their state and federal obligations regarding bridge safety inspection work.

They will also help locals with deployment and implementation of advance bridge inspection equipment and much more! Obviously, these posi-

tions will likely evolve over time and may spring additional growth with SA Assistant Regional TL Specialists to meet the growing demands. Cur-

rently, the CEBC is recommending a South (D 6, 7, & 8) and North (D 1, 2, 3, & 4) SA Regional TL Specialist to start with. These positions will model

after the SA Regional Construction Specialists, but with roles to provide overall local bridge inspection program assistance, local bridge inspection

guidance and training, local bridge operation support, and SA District operation support, etc.

(continue on page 14)

Nonextant Township Bridge L1847, Single Span Riveted Warren Truss over the South Fork Pine River in Cass

County. Picture showing an UB-30 (under bridge inspection unit), This snooper truck is designed to be used on

small load posted bridges with a load posting of 18 tons or greater. Bridge L1847 was replaced back in 2013

with a prestressed concrete beam span.

14

…continued, Routine Local Bridge Safety Inspection Assistance Update

State Aid Bridge, with cooperation from the Bridge Office Inspection Unit, and the CEBC, have developed detailed position descriptions for these

new State Aid roles. Tentatively, we envision these positions being housed in a State Aid District Office at a location where the employee resides.

They will be direct reports to the SA Bridge Engineer/ SA Bridge Load Rating Engineer with SA District influence. Their clientele will range from

Local Agency Bridge Program Administrators, Inspection Personnel, to Local Bridge Consulting Engineers. These new roles will be monitored by

the CEBC as well to help evolve them over time. We’re excited to get these new positions in play for our locals, hopefully for the 2021 Local

Bridge Safety Inspection season.

Local Standard Bridge Plans Update

Back in 2019 we unveiled the development of inverted tee beam standard superstructure plans. Please revisit our 2019 State Aid Bridge News (PDF) on

page 13 for the pertinent background information. The inverted tee beam standards project is being championed by the Bridge Office under Paul

Kettleson’s State Bridge Design Unit with support from multiple functional areas of the Bridge Office, including State Aid Bridge. Paul’s Bridge Design Unit

staff have been working diligently on this project over the past six months. Balancing other project delivery demands for MnDOT and this special effort for

local bridge owners has been challenging to say the least. Developing any kind of bridge design standard plan comes with extra scrutiny and detailed

reviews from our Bridge Office experts. Minnesota’s inverted tee beam bridges have evolved over time to address better serviceability and performance

through supporting research from the U of M (University of Minnesota) and inspection history of in-service local and state inverted tee bridges. The

inverted tee beam standard superstructure plan development process is carefully integrating the latest design and details reflected from the U of M

research and past inverted tee beam bridge performance history. Additional time is being taken to assure the standard inverted tee beam basis of design

and detailing history is very well documented for future custom inverted tee beam designs and adaptability to accommodate evolving AASHTO bridge

design specifications. The inverted tee beam standard superstructure plans are progressing, and we’re hopeful we’ll have draft standard designs and plans

to review relatively soon. From a draft version to publication is still quite a process and will entail both industry and local bridge consultant input/feedback.

The standards should be available for the 2022 construction season.

In 2018 we discussed Standard Bridge Plans for Local Bridge Owners, see our 2018 State Aid Bridge News (PDF) on page 13 for particulars. At the latest

County Engineers Bridge Committee (CEBC) meeting, seeking and developing standard local bridge plans is still of broad interest. Last year at this time

Tim Stahl, Jackson County Engineer and CEBC member passed along some interesting secondary route bridge design plan guides the MDOT (Michigan

DOT) LAP (Local Agency Program) developed through Wayne State University. State Aid Bridge connected with Keith Cooper who serves as the MDOT

Local Bridge Program Manager regarding this effort for Michigan local bridge owners. Here is the link to MDOT’s Local Agency Bridge Program website

https://www.michigan.gov/mdot/0,4616,7-151-9625_25885_40558---,00.html. The Secondary Route Bridge Design Plan Guides and Final Report” is

located in the middle of the page. Note these are typical and cost-effective standard superstructure design plans for Michigan and they include a single

span steel girder bridge, prestressed spread box beam bridge, prestressed bulb tee beam bridge, and an SBS (side by side) prestressed box beam bridge.

However, I understand from Keith that MDOT has eliminated the use of side by side post tension box beam bridges due to excessive deterioration and

longevity issues. Apparently the SBS box beam standard plans were developed prior to this moratorium. Local agencies typically preferred this type of

structure due to the thinner profile. Improvements were made about eight years ago requiring local agencies to have a 6” concrete deck and a closed

bridge railing. Much of the deterioration in the past was caused by open bridge railings and a 1 ½” asphalt wearing surface on the deck.

According to Keith, they encourage and have been successful in getting

their local agencies to use other superstructure designs. GRS-IBS

abutments are also being used, and they encourage using precast

concrete boxes, when possible, since they are the most cost effective.

Based on Keith’s feedback and what the MDOT Local Agency Program

developed on standard bridge superstructures plans to date, the

Minnesota Local Bridge Program seems to be headed in the right

direction. With the advent of the new inverted tee beam standard

superstructure plans, new precast concrete box culvert standards with up

to 20’ culvert widths, implementation of GRS-IBS abutment technology

and other innovative local bridge strategies, we’re feeling the momentum

shift to best support our local bridge owners. SA Bridge, under direction

from the County Engineers Bridge Committee, will continue to explore

and find opportunities for cost savings, efficiencies, fast constructing and

long-lasting local bridges. Our other transportation partners which include fabricators, and local bridge consultants will be engaged in these endeavors.

Inverted Tee Beam Bridge 69A34, County Road 180 over Bog Creek, St Louis County

15

Rural Bridge Project

Back in June 2020, State Aid Bridge was contacted by the Soy

Transportation Coalition to participate on an advisory committee to

help develop resources and other promotional information that

would highlight the “Top 20 Rural Bridge Replacement and Repair

Innovations.” Individuals serving as principal analyst for the project

included: Brian Keierleber (Buchanan County, Iowa), Pat Conner

(LTAP Program at Purdue University), and Kelly Bengston (Upper

Great Plains Transportation Institute at NDSU). The project was led

by Mike Steenhoek, Executive Director of the Soy Transportation

Coalition. Other states involved in the project include: Kansas, South

Dakota, Illinois, Michigan, Nebraska, Ohio, Tennessee, and Missouri.

When selecting the various innovations for bridge replacement and

repair, they needed to meet three criteria, is the concept valid from

an engineering perspective, will the concept provide cost savings

compared to the prevailing method, and is the concept accessible

and applicable in a wide array of rural America?

Bridge replacement innovations from Minnesota that can potentially

meet the criteria include GRS- IBS abutments and inverted tee beams. We have additional information/updates on these technologies in this

State Aid Bridge News, and the 2014, 2015, and 2019 State Aid Bridge News. Meeting the three criteria above is somewhat ambitious, but it

certainly generated some interesting innovations from other states. For the innovative bridge replacement ideas, the advisory committee

included: buried soil structures, GRS-IBS abutments, inverted T beams, press brake tub girders, rail flat car (from Iowa), prestressed deck panels,

vibratory H-piling drivers, all steel piers, and galvanized steel beams and piles. And for the Innovative bridge repair ideas, the advisory committee

included piling encasements, concrete pier piling repair, driving piling through decks, epoxy deck injections, deck patching, spot cleaning/

painting steel beams, deck overlays with type O concrete and plasticizers, thin polymer concrete overlays, penetrating concrete sealers, and

concrete overlay on adjacent box beams.

We understand the promotional information highlighting the “Top 20 Rural Bridge Replacement and Repair Innovations” will be available very

soon through the Soy Transportation Coalition. It should be noted that the listed innovations, although valid from an engineering perspective,

accessible to rural America, and can potentially provide cost savings, are not necessarily being practiced in Minnesota. However, this project has

the possibility to bring additional recognition throughout the country of these rural bridge replacement and repair innovations.

Sunrise Township Br 13J13, Kost-Dam Road over Sunrise River, Chisago County. A 60’ span buried

precast concrete arch structure.

Local Bridge Replacement Program

The local agency and governor’s support of a $100 million of new Local Bridge Replacement Program Funding (LBRP) for the start of the 91st Legislative

Session in 2020 began with lots of optimism. Hopes were high for the quick passage of a capital improvement transportation bill which would include

funding for the LBRP. In March the COVID virus surfaced and suddenly this crazy scary virus became the focus of the legislature and the passage of a

bonding bill was thwarted by the virus. However, because of this new virus, 2020 also proved to be the year of many special sessions at the legislature.

These special sessions proved to be a life support for the local bridge program. During the 5th Special Session in October, the legislature reconvened and

passed a capital improvement bill. The bill included $30 million of State Transportation Funds for the local bridge replacement program and an additional

$52 million for a grant to the City of Saint Paul for the right of way, design, and construction of a new bridge on Third Street/Kellogg Boulevard over the

BNSF Railroad, Commercial Street, and Interstate 94.

In addition to the $30 million of bonding made available, the LBRP also received $11.4 million in State Transportation Funding generated from 13 percent

of the motor vehicle lease sales tax revenues collected in 2019. These funds become available in September the year after they are collected.

Counties administer and receive town bridge funding annually for the replacement of deficient bridges on town roads. These bridge funds are distributed

to counties based on the number of deficient town bridges and the average bridge replacement cost in the previous year. Counties and townships replaced

52 bridges in 2020 and spent approximately $14.9 million in town bridge funds. The town bridge funds are distributed in January and originate from the

Highway User Tax Distribution Fund. This consistent and dedicated funding source for township bridges has been crucial for replacing deficient town

(continue on page 16)

16

Bridge Cost Update Calendar year 2020 saw a small unit cost increase for PCB type structures and a small unit cost increase for the C-SLAB type structures. These two

structure types account for the majority of local bridges. As usual, the C-SLAB structure type was the lowest unit cost structure on the local

system.

We let four pedestrian TRUSS structures in CY 2020 and the unit cost was slightly down from last year. Steel truss bridge prices fluctuate greatly

from year to year and likely reasons are the size/length/location of these bridges which can vary widely, and these factors can affect the unit cost.

We let one treated timber slab (TTS) span bridge in CY 2020. There was a very large unit cost increase from last year.

We let two Pedestrian Boardwalk (BRDWLK) bridges in CY 2020. There was a moderate unit cost decrease from the CY 2019 unit cost.

There was a small increase in the number of C-SLAB bridges compared to CY 2019 (13 let in CY 2020 vs. 11 let in CY 2019). There was a small de-

crease in the number of PCB bridges compared to CY 2019 (13 let in CY 2020 vs. 16 let in CY 2019). The unit cost percentage increases/decreases

are shown below.

• PCB structure cost was up 3 percent ($160.81/sf in CY 2019 vs. $166.18/sf in CY 2020)

• C-SLAB structure cost was up 3 percent ($130.34/sf in CY 2019 vs. $134.74/sf in CY 2020)

• TRUSS pedestrian structure cost was down 1 percent ($274.47/sf in CY 2019 vs. $271.55/sf in CY 2020)

We removed approximately 38 timber bridges and two fracture critical

bridges from the local bridge inventory in CY 2020. Most bridges get

replaced by new structures, but some don’t get replaced (Road in Lieu

Projects). Timber bridges are considered to be full timber construction

or timber pile/abutment construction. Fracture critical bridges are steel

high trusses, steel low trusses, or thru-girder bridges.

Of the 38 timber bridges replaced in CY 2020, 28 of them were replaced

with concrete box culverts, four were replaced with C-SLAB bridges,

and four were replaced with PCB bridges. There was a single timber

bridge that was replaced with concrete arch pipes. There was a single

timber bridge and a single fracture critical bridge (a steel low truss) that

were removed from the system, via ROAD IN LIEU projects. The other

fracture critical bridge was replaced with a C-SLAB bridge.

…continued, Local Bridge Replacement Program

bridges throughout the state. Counties are encouraged to make sure the bridge improvement cost estimates for your township bridge projects are

updated in the bridge inventory data to reflect accurate bridge replacement costs. Instructions can be found on the SALT LBRP webpage.

Locals managed through the challenges of working under the umbrella of the COVID virus and 117 bridges were either funded and are on schedule

for replacement or were replaced in 2020. The cost of these bridges totaled $58.4 million. These bridges utilized a combination of federal, state

aid, local, state transportation funds (bond or MVLST), and town bridge funds.

State Aid will start 2021 with approving bridge projects currently on the bridge waiting list with the $30 million of bond funds and the $11.4 million

of MVLST funds that became available in 2020. The funding will run out before all the projects on the list are funded, but we anticipate most of

them will be funded and taken off the list. Newly approved projects will be added to the waiting list as a bridge plan moves through the State Aid

project approval process.

We encourage you to visit the SALT LBRP webpage.for the history, details, and information on the LBRP. There are also links to tools on various

resolutions, such as how to advance county regular/county municipal funds to supplement the Town Bridge Account. Tools on how to create a

prioritized bridge replacement list, and to amend a prioritized bridge replacement list is also provided. For more Information contact Patti Loken,

State Aid Program Support Engineer at patti.loken@state.mn.us or 651-366-3803.

17

Load Rating and Permitting Update

SHV load rating contract

We are currently in SHV load rating contract VII that has approximately 825 local bridges that are

being evaluated. The contract consists of metal and concrete culverts, timber bridges, simple

span steel and concrete bridges, and complex structures such as post-tensioned slab, trusses, etc.

In addition to load rating and load posting analysis of local bridges, the SHV contract also included

re-load rating bridges non-compatible with the AASHTOWare BrR program for EV (emergency

vehicles) and overweight permit vehicles that were not included in previous SHV load rating con-

tracts. This additional work required the evaluation of bridges for EV and overweight permit vehi-

cles (A, B, C trucks) and annotating the load rating form without the need to perform field inspec-

tion and completing a new load rating form. This effort will not only fulfill the FHWA requirement

of evaluating local bridges for emergency vehicles, but also will help local agencies with their overweight permitting operation. Due to the COVID-19 pan-

demic, there were many challenges that were presented to our local bridge consultants working on the SHV contract especially during the spring of 2020

when small businesses, restaurants and hotels were ordered to be closed. Our consultants were not able to stay at hotels overnight therefore sometimes

having to make multiple trips to inspect bridges in the same local agency. Also, social distancing presented some obvious challenges as well. Inspection

teams had to drive in separate vehicles to the bridge sites and practice social distancing while they performed their bridge inspections. For these reasons,

bridge inspections took much longer, and some submittal deadlines had to be extended. Eventually our consultants came up with strategies, efficiencies,

and adjusted to the situation. State Aid Bridge and our local bridge owners really appreciate the hard work that our consultants have put forward during

these challenging times. Regarding the new electronic load rating forms that were successfully used in the SHV contract, and fully implemented on May

29, 2020 for new local bridges as well, has been a good initiative to eliminate common load rating errors. Some common mistakes that were often made

when completing a load rating form such as the load posting requirements, load rating values and the type of load rating method used were eliminated.

Also, the load rating data entry process into SIMS (Structure Information Management System) has been smooth and error free. For more background

information, see 2020 State Aid Bridge newsletter (PDF) on page 14.

SHV load rating contract VIII

The next SHV load rating contract will have approximately 850 local bridges that will need to be evaluated. It’s a one-and-a-half-year contract that will

include timber bridges that are in poor condition along with cast-in-place and precast concrete culverts, simple bridges and a few complex structures. In

addition to load rating and load posting analysis work, the contract will also include developing an online GIS based map for Emergency Vehicles and a

new Concrete Culvert Load Rating Guide. Note, we will continue to evaluate local bridges for EV in response to the memo that was issued by the FHWA

regarding emergency vehicles. The federal law requires us to load rate and post our bridges for emergency vehicles. According to the memorandum,

bridges that require posting for EV and are within a one-road mile of an interstate shall be physically load posted for EV. MnDOT currently does not have a

weight limit sign dedicated for EV at the moment, but is currently working to develop one similar to either Figure 1 or 2 below. These two figures are EV

posting sign examples that are being recommended by the FHWA’s MUTCD Team.

For bridges that require EV posting and are outside the one-road mile of an interstate do not necessarily need to be physically posted for EV. But to assure

public safety, it is important for local fire departments and EV operators to know whether or not local bridges within their jurisdiction restrict the use of

(continue on page 18)

3-Axle Fire Truck Apparatus

Figure 1: EV sample plaque that would go below an existing R12-5 sign Figure 2: Standalone EV sign

18

MnDOT Bridge Office

3485 Hadley Ave N., MS 610

Oakdale, MN 55128 http://www.dot.state.mn.us/stateaid/bridge/

State Aid

Bridge

Contacts:

Dave Conkel

dave.conkel@state.mn.us

State Aid Bridge Engineer

651-366-4493

Brian Homan

brian.homan@state.mn.us

State Aid Bridge Plans Engineer

651-366-4494

Steve Brown

steve.brown@state.mn.us

State Aid Bridge Sr. Bridge Plans Specialist

651-366-4495

Moises Dimaculangan

moises.dimaculangan@state.mn.us

State Aid Bridge Load Rating & Permitting Engr.

651-366-4522

Erik Brenna

erik.brenna@state.mn.us

State Aid Bridge Hydraulics Engineer

651-366-4536

Nolan Bach

nolan.bach@state.mn.us

State Aid Bridge Graduate Engineer

651-366-4524

…continued, Load Rating and Permitting Update

their vehicles to avoid potential bridge damage and safety risks. For this reason, the additional task of developing an online GIS based map of local bridges

that require posting for EV was added to the contract as mentioned above. The map will provide EV weight restriction information of local bridges which

can be used as a tool to educate fire departments and local agencies about load postings for EV as well as to illustrate where the load posted structures are

located. For more background information, see 2017 State Aid Bridge newsletter (PDF) on pages 11-12. Also mentioned above is the other important task

that was added to the SHV contract which consists of developing a Concrete Culvert Load Rating Guide. With so many concrete culverts on the local sys-

tem, the guide will provide direction on how to best load rate these types of structures. This document will provide uniformity in the load rating process of

all concrete culverts and ensure that they are load rated to their safe load carrying capacity.

Implements of Husbandry on bridges - NCHRP project update

Lastly, load rating and load posting evaluation for IoH (implements of husbandry) is emerging. The

NCHRP project called Proposed New AASHTO Load Rating Provisions for Implements of Husbandry

has been completed and the report has been published on the Transportation Research Board (TRB)

website. These provisions provide bridge load rating procedures and protocols for IoH. With these

new provisions, we envision that the 2022 SHV load rating contract IX will initiate IoH evaluations

with more information to come. For more background information, see 2017 State Aid Bridge news-

letter (PDF) on page 13.

Tractor Honey Wagon