25th Avenue Grade Separation Project

Night Work Mitigation Efforts

The majority of the construction work for the 25th Avenue Grade Separation Project will occur during the day. However, some activities will need to be conducted during nights and weekends outside of normal train service hours, due to their close proximity to the railroad tracks. In an effort to mitigate the noise, Caltrain is doing the following:

  • Single tracking its trains on evenings when night work is scheduled in an effort to start construction earlier.
  • During the shoring/sheet pile work
    • Pre-drilling will occur in an effort to mitigate the noise. The project has found pre-drilling reduces the average noise level by +/-13db. Pre-drilling will also occur during the day.
    • Starting mid/late December, a different crew and equipment will be used in an effort to better mitigate noise.
    • Please note: a sound wall is not possible as the shoring equipment moves approximately 35 to 40 feet into the air and a sound wall of that height would require a foundation that would pose a safety issue due to its close proximity to the tracks.
  • For the cast-in-drilled-hole piles (CIDH) work, Caltrain obtained additional equipment and the services of another crew in mid/late December to allow for faster completion of this activity.