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HomeMy WebLinkAboutLansing Bridge Inspection - Executive Summary 2017City of Lansing 2017 Bridge Inspection Report EXECUTIVE SUMMARY 1. Federal and State Requirement Inspection of bridges is required for all structures on the National Bridge Inventory (NBI) by the Federal Government through the Code of Federal Regulations 23 CFR Part 650 entitled the National Bridge Inspection Standards (NBIS). NBIS requires that inspection be performed by a qualified bridge inspector. NBIS establishes maximum bridge inspection frequencies for each type of bridge safety inspection. Routine inspections must occur at regular intervals that do not exceed 24 months. The regulations also require each state to establish criteria for reduced inspection frequencies through the consideration of factors such as age, traffic characteristics, and condition state. The NBIS does not apply to tunnels, bridges that carry only pedestrians, railroad tracks, pipelines, or other types of non-highway passageways. However, MDOT requires that all structures that are over moving traffic be inspected to the same guidelines as NBIS. For bridges over waterways there are additional requirements based on scour concerns, including scour action plans, taking waterway cross sections, and underwater inspections. Scour action plans are required for all bridges that are deemed scour critical. To determine if a bridge is not scour critical, a scour analysis is required. There are two levels of scour analysis. A Level One analysis is the first step and it consists of gathering information that covers stream characteristics, land use, stream stability, lateral stability, vertical stream stability, and channel response to change. If the results of a Level One analysis do not conclude that a bridge is not scour critical then a Level Two analysis is required. A Level Two scour analysis is an analytical process to define stream stability and scour problems that incorporates flood history, hydraulic conditions, geotechnical evaluation, watershed sediment yield, incipient motion analysis, armoring potential, rating curve shifts, and scour conditions. For all bridges that are scour critical, a scour action plan needs to be created. These action plans need to be updated each time a routine inspection is completed at a minimum, as well as after each major storm event. Waterway cross sections frequency is determined based on MDOT’s Guidelines for Bridge Inspection Frequencies. The City of Lansing’s bridges that are coded as scour critical have not had any observed scour, so the cross section frequency is 48 months. Underwater inspections are performed where the water depth exceeds 10 feet where normal probing is not sufficient to detect any signs of scour. All bridges where the water depth meets these requirements require an underwater inspection regardless if the bridge is scour critical or not. The City has six bridges that require underwater inspections. All six bridges have a 60 month inspection frequency. Bridge load ratings need to be updated any time work has been done to a structure that has changed the loading to the bridge, or the condition of the bridge has dropped to a level where the load carrying member capacities have been reduced. City of Lansing 2017 Bridge Inspection Report 2. Bridge Inspection Frequency This year’s routine inspections were completed for all of the City’s bridges. All of the City’s bridges are on a 24 month inspection cycle, except where noted otherwise below: 1 - Woodgate Walkover over Miller Road 2 - Wexford Road Walkover over Jolly Road 3 - Averill Walkover over West Holmes Road 4 - Ray Street Walkover over East Mount Hope Avenue 5 - Harding Avenue Walkover over East Mount Hope Avenue 6 - Holmes Street Walkover over East Kalamazoo Street 7 - Massachusetts Avenue Walkover over East Grand River Avenue 8 - Newark Street Walkover over Pleasant Grove Road 9 - Pleasant View School Walkover over Pleasant Grove Road 10 - Willow Street Walkover over North Martin Luther King Jr. 11 - Kendon Walkover over Pennsylvania Avenue 12 - Potter Park River Trail over Pennsylvania Avenue 13 - Harley Franks School Walkover over Wise Road 14 – N/A 15 - Grand Trunk Railroad over Pennsylvania Avenue 16 - Jolly Road over Sycamore Creek 17 - Cavanaugh Road over Sycamore Creek 18 - Mount Hope Avenue over Sycamore Creek 19 - Elm Avenue over the Grand River 20 - East Elm Street over the Red Cedar River (12 month inspection cycle) 21 - Kalamazoo Street over the Grand River 22 - Shiawassee Street over the Grand River 23 - East Grand River Avenue over the Grand River 24 - North Martin Luther King Jr. Boulevard over the Grand River 25 - North Grand River Avenue over the Grand River 26 - South Washington Avenue over the Grand River 27 - Pennsylvania Avenue over Norfolk Southern Railroad 28 - Pennsylvania Avenue over the Red Cedar River 29 - Aurelius Road over Sycamore Creek 30 - Aurelius Road over the Red Cedar River 31 - Aurelius Road over Grand Trunk Railroad (12 month inspection cycle) 32 - Beech Street over Red Cedar River 33 - Aurelius Road over Pawlowski Creek Drain (12 month inspection cycle) 34 - N/A 35 - Enterprise Drive over Pawlowski Creek Drain City of Lansing 2017 Bridge Inspection Report 3. Summary of RFA’s and Work Recommendations The list of work recommendations can be seen in the Bridge Maintenance Items and Priorities Table. The following is a summary of the Requests for Action that were submitted this year:  Pennsylvania Avenue over the Red Cedar River – Replace the missing railing on the east side of the bridge. 4. Underwater Inspection Underwater inspections were performed in 2013 and 2015. Since the City’s bridges requiring underwater inspection have a 60 month frequency, no underwater inspections were required this year. The following bridges will require underwater inspections in 2018: I. Pennsylvania over Red Cedar II. Aurelius over Red Cedar The following bridges will require underwater inspections in 2020: I. Elm Avenue over Grand River II. East Elm Street over Red Cedar River III. Kalamazoo Street over the Grand River IV. Shiawassee Street over Grand River 5. Scour Criticality, Channel Cross-Sections and Scour Action Plans Channel cross-sections are taken and plotted for the bridges that are over water and are currently considered scour critical. The cross-sections are taken on both the upstream and downstream faces of the bridge. The purpose of the cross-sections are to determine if the channel is changing over time which could provide an indication of ongoing scour. Small variations in the channel cross-sections are to be expected due to difficulties in taking elevations underwater and since the measurements are not taken in the exact same locations each time. Since the channels appear stable without notable change, the channel cross-sections are on a four-year cycle. Since channel cross-sections were taken for all of the City’s scour critical bridges in 2015, no channel cross-sections were taken this year. Due to the presence of scour countermeasures and stable cross-sections, the following bridges have been removed from the list of scour critical bridges: I. Jolly Road over Sycamore Creek II. Cavanaugh Road over Sycamore Creek III. South Washington Avenue over the Grand River IV. Aurelius Road over Sycamore Creek V. Aurelius Road over Pawlowski Creek Drain VI. Enterprise Drive over Pawlowski Creek Drain City of Lansing 2017 Bridge Inspection Report The following bridges remain listed as scour critical and will require channel cross-sections in 2019: I. Mount Hope Avenue over Sycamore Creek II. Elm Avenue over the Grand River III. East Elm Street over the Red Cedar River IV. Kalamazoo Street over the Grand River V. North Martin Luther King Jr. Boulevard over the Grand River VI. North Grand River Avenue over the Grand River VII. Pennsylvania Avenue over the Red Cedar River VIII. Aurelius Road over the Red Cedar River 6. Load ratings The following bridges have had work performed on them in 2017 and load ratings have been updated as part of the design project: I. Jolly Road over Sycamore Creek II. Cavanaugh Road over Sycamore Creek III. Elm Avenue over the Grand River IV. Aurelius Road over Sycamore Creek 7. Completing the process After the inspections are complete, the reports are completed on MDOT’s MiBridge website. The results of the inspection are then reviewed by the City of Lansing to determine which bridges will be submitted to receive funding under the Michigan Local Agency Bridge Program. 8. Upcoming Inspections Three bridges will be inspected in October 2018: I. East Elm Street over Red Cedar River II. Aurelius over Grand Trunk Railroad III. Aurelius over Pawlowski Creek The next full round of biennial inspections will be held in October 2019.