Difference between revisions of "Tunnel Rehabilitation"

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'''Rehabilitation'''
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=Primary Guidance=
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:* Assume only nighttime tunnel closure windows will be available to complete the proposed work.
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:* Coordinate with appropriate tunnel operations staff.
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= Discussion =
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== General ==
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=== The following MDOT TBUs own and maintain transportation tunnels: ===
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:* Maryland Transportation Authority (MDTA)
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:** Fort McHenry Tunnel (FMT) – Interstate 95 under the Patapsco River
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:** Baltimore Harbor Tunnel (BHT) – Interstate 895 under the Patapsco River
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:* Maryland Transit Administration (MTA)
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:** Baltimore Metro – Baltimore Metro Subway under Baltimore City
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:* Fort McHenry and Baltimore Harbor Tunnels
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::* Rehabilitation project designs must be closely coordinated with the appropriate tunnel operations staff.  In almost all cases, shutting down a tunnel bore for an extended period is not possible due to the resulting severe traffic impacts from the reduced traffic capacity.  Operations staff for both tunnels develop and maintain weekly nighttime closure schedules for the tunnel bores. 
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:::* BHT: weekly nighttime closures Monday through Thursday only, from 9:00 am to 4:30 am
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:::* FMT: southbound closures 7:00 pm to 4:30 am; northbound closures 8:00 pm to 4:30 am. 
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::* Routine maintenance work is scheduled to coincide with nighttime closure schedules and needs to be accounted for during project design.  While closure schedules and maintenance operations are subject to change, they must be used as a basis for developing how proposed rehabilitation work can be performed and sequenced.
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Shoulder pavement will not be designed to be the same thickness as mainline roadway.  Except for the following exceptions, shoulder pavement design will be based on 10 percent of the mainline Average Daily Truck Traffic (ADTT) :
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*Bridge Approaches, within 500 ft. of bridge
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*Intersections, within 500 ft. of intersection
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*Shoulders less than 6 ft. wide
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There is a significant likelihood that shoulders will be used for Maintenance of Traffic (MOT)  at bridge approaches and converted to turn lanes at intersections.  When less than 6 ft. wide, it is impractical to construct shoulders in a separate pass from the
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[[Category:Practical Design Guidance]][[Category:Secure]]
 
[[Category:Practical Design Guidance]][[Category:Secure]]

Revision as of 18:44, 8 May 2017

Rehabilitation

Primary Guidance

  • Assume only nighttime tunnel closure windows will be available to complete the proposed work.
  • Coordinate with appropriate tunnel operations staff.

Discussion

General

The following MDOT TBUs own and maintain transportation tunnels:

  • Maryland Transportation Authority (MDTA)
    • Fort McHenry Tunnel (FMT) – Interstate 95 under the Patapsco River
    • Baltimore Harbor Tunnel (BHT) – Interstate 895 under the Patapsco River
  • Maryland Transit Administration (MTA)
    • Baltimore Metro – Baltimore Metro Subway under Baltimore City
  • Fort McHenry and Baltimore Harbor Tunnels
  • Rehabilitation project designs must be closely coordinated with the appropriate tunnel operations staff. In almost all cases, shutting down a tunnel bore for an extended period is not possible due to the resulting severe traffic impacts from the reduced traffic capacity. Operations staff for both tunnels develop and maintain weekly nighttime closure schedules for the tunnel bores.
  • BHT: weekly nighttime closures Monday through Thursday only, from 9:00 am to 4:30 am
  • FMT: southbound closures 7:00 pm to 4:30 am; northbound closures 8:00 pm to 4:30 am.
  • Routine maintenance work is scheduled to coincide with nighttime closure schedules and needs to be accounted for during project design. While closure schedules and maintenance operations are subject to change, they must be used as a basis for developing how proposed rehabilitation work can be performed and sequenced.




Shoulder pavement will not be designed to be the same thickness as mainline roadway. Except for the following exceptions, shoulder pavement design will be based on 10 percent of the mainline Average Daily Truck Traffic (ADTT) :

  • Bridge Approaches, within 500 ft. of bridge
  • Intersections, within 500 ft. of intersection
  • Shoulders less than 6 ft. wide

There is a significant likelihood that shoulders will be used for Maintenance of Traffic (MOT) at bridge approaches and converted to turn lanes at intersections. When less than 6 ft. wide, it is impractical to construct shoulders in a separate pass from the