Project Number:

3704

Underwater Sound Monitoring of Fore River Bridge Pile Driving

SERVICE:

Acoustic Consulting on Bridge Construction

DESCRIPTION:

Tech provided underwater sound monitoring during the pile driving for the Fore River Bridge Replacement Project using a B&K Model 8104 Hydrophone. The sampling train was designed to measure undersea sound over a spectrum of 12 Hz to 20 kHz, which covers the hearing range of most marine mammals, sea turtles, and fish. For this bridge construction project, National Marine Fisheries Service (NMFS) established adverse effect thresholds for sea turtles and Atlantic Sturgeon. Sound monitoring of both impact hammering and vibratory pile installation was done. All vibratory hammering sound levels were found to be in compliance with NMFS criteria at a setback distance of 150 feet. A slightly larger exclusion zone of 220 feet radius was recommended during impact hammering to ensure sound levels do not exceed NMFS criteria to protect sea turtles.

Print   Email

Key Points

  • Tech performed underwater sound monitoring to assess the effects of impact hammering and vibratory pile installation on marine animals.
  • From the monitoring, Tech concluded that the vibratory hammering sound levels were in compliance, but recommended an exclusion zone with a 220 foot radius during impact hammering.