Bridge Replacement and Improvement Management Tool for Local Bridges BRIM David Conkel, MnDOT State Aid Bridge Davide Hedeen, MnDOT Bridge Barritt Lovelace, Collins Engineers

MnDOT State Aid | mndot.gov Project Overview 15,821 Bridges in Minnesota owned by local agencies Local bridges vary widely by type and size BRIM tool developed in the past year Offers a risk based approach to bridge improvements MnDOT State Aid | mndot.gov

Goals and Deliverables Meet FHWA MAP-21 Act Requirements Develop tool for local bridge owners to aid in managing bridge inventories Software and database tool Provide an easy to use tool to local bridge owners Help local bridge owners make decisions on bridge maintenance, rehabilitation and replacement MAP 21 requires DOT’s to apply a risk bases approach to maintaining assets. BRIM aids local bridge owners The tool is a software and database tool which uses inventory and inspection data. Tool is easy to use and understand. Give bridge owners another tool to make risk based data driven decisions. MnDOT State Aid | mndot.gov

Local vs. Trunk Highway BRIM TH BRIM focused on bridge decks Local BRIM focused on rehabilitation and replacement Local BRIM involves almost 200 bridge owners More bridges on the local system Bridge Types Timber Culverts MnDOT has successfully implemented a BRIM program. The local BRIM is similar but key differences: Local bridges vary more in type, location, ADT etc. Timber bridge more common on local system Culverts half of the local inventory May be used for inspection frequency in the future. MnDOT State Aid | mndot.gov

Local Bridge Inventory Large variety of bridge types and material on local system. Majority are culverts. MnDOT State Aid |  mndot.gov/

MnDOT State Aid | mndot.gov Risk Concept Risk Level for Service Interruption = Likelihood X Consequence Service Interruption - When a bridge no longer performs as intended. If a bridge has an adverse event, some may have a larger consequence than others Each bridge is not equal, and some bridges are more likely to have an adverse event We are defining risk based on service interruptions. Service interruption is when the bridge no longer performs as intended. Not necessary a bridge collapse. Could be reduced service. Looking at both likelihood and consequence of failure. Likelihood=The chance that a service interruption will occur. Consequence=The impact a service interruption will have on the traveling public. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Risk Concept As we increase the consequence of failure and the likelihood our risk increases. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Risk Concept Assessing Risk Benefits Avoid service interruptions Improve safety Plan maintenance, repairs, replacements Spend budgets more wisely Benefits of using risk to assess our bridge inventory. Avoid service interruptions Improve safety Plan maintenance, repairs, replacements Spend budgets more wisely MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Risk Concept Collect Data We are doing this through our inventory and inspection program. Assess our bridges, load rating a good example. Analysis This is where the BRIM tool comes in. Decision Make data driven decisions based on our risk based approach MnDOT State Aid | mndot.gov

Local (Bridge) Planning Index (LPI) LPI = 100-(Probablility x Consequence) Range from 1-100 1 is the Highest Priority 100 is the Lowest Priority The LPI is a risk score which factors both the consequence of a service interruption and the probability of service interruption. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Probability Bridge Condition Vertical clearance Scour Load Rating Fatigue Fracture Critical Status These factors contribute to the probability of a failure. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Consequence Traffic Volume (ADT) Detour Length Bridge Length Local Considerations Industry/Trade Agriculture These factors increase the consequence of failure. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Example Calculation A MathCAD Example Calculation is available for download to help bridge owners understand the calculation steps to determine the LPI. There is one version available for bridges and one for culverts. MnDOT State Aid | mndot.gov

Probability Scaling Table Scaling tables used to determine probability scores Example shown is the probability for a deck Based on NBI Condition and Crack Density Scaling tables use to determine probability scores for deck, superstructure, substructure, scour, fracture critical status, load rating and vertical clearance. Example shown is for the deck MnDOT State Aid | mndot.gov

Importance Factor Table Table used to determine importance factors Example shown is the importance factor for ADT Tables also used to determine importance factors which include ADT, detour, length and bridge width. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Report Access Hosted on the MnDOT Website http://www.dot.state.mn.us/stateaid/bridge/localbrim/ Results viewed as a report ranking bridges 100 Least Risk 0 Most Risk A MathCAD Example Calculation is available for download to help bridge owners understand the calculation steps to determine the LPI. There is one version available for bridges and one for culverts. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov BRIM LPI Report Example report from Chisago County. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Benefits Improvement on sufficiency rating Easy to obtain data Data is as current as inspection data Easier to follow than the sufficiency rating Another tool for owners to make decisions Encourages maintenance The LPI is an improvement on the sufficiency rating from FHWA and uses a more risk based approach. The sufficiency rating is no longer being used by FHWA. The data is easy for a bridge owner to obtain, just need to download from MnDOT website. Data is always as current as the inspection data that is in the SIMS database. Sufficiency rating was more of a black box. Individual bridge calculations can be reviewed by inputting bridge data in the MathCAD workbooks. The tool will hopefully encourage early and appropriate maintenance. MnDOT State Aid | mndot.gov

Bridge Owner Action Items Review the workings behind the LPI Compare the LPI report against existing priority lists Consider reprioritizing based on LPI information Work with DSAE, Patti and Dave for funding eligibility Funding still tied to sufficiency rating and status (SD, FO) Use LPI list to plan maintenance and repairs Reevaluate your list annually or as inspection information changes Review the workings behind the LPI, review MathCAD example calculations to understand factors affecting score Compare the LPI report against existing priority lists Consider reprioritizing based on LPI information Work with DSAE, Patti and Dave for funding eligibility Funding still tied to sufficiency rating and status (SD, FO) Use LPI list to plan maintenance and repairs, try to bring scores up Reevaluate your list annually or as inspection information changes David Hedeen, Dave Conkel, Moises Dimaculangan or Patti Loken are available to answer questions. MnDOT State Aid | mndot.gov

Accessing Report Available through the Bridge Reports Website Located the Bridge Lists folder

Customizing Report

Cover Report

LPI Summary Listing

Detail/Visualization of LPI Reduction

Demonstration of Weight Effects

Demo Found in the Bridge Reports Repository http://dotapp7.dot.state.mn.us/bridgereports/ Also linked MnDOT’s Bridge Inventory Page

LPI vs Sufficiency Rating

MnDOT State Aid | mndot.gov Project Team Dave Conkel, MnDOT Dave Hedeen, MnDOT Moises Dimaculangan, MnDOT Brian Homan, MnDOT Dustin Thomas, MnDOT Patti Loken, MnDOT Jake Bronder, Hennepin County Barritt Lovelace, Collins Engineers Matt Hemmila, St. Louis County Lance Robertson, St. Louis County Willy Rabenberg, Redwood County Brian Pododzinski, Houston County Ron Benson, Stonebrooke Engineering Jamison Beisswenger, SRF Brent Christensen, City of St. Paul Jack Yuzna, City of Minneapolis Jon Siiter, LHB Inc. Rachel Litfin, St. Louis County Thank you to the team members who contributed their time and energy to this effort. MnDOT State Aid | mndot.gov

MnDOT State Aid | mndot.gov Questions? MnDOT State Aid | mndot.gov