Highway projects

Earthquake Ready Burnside Bridge Project

Multnomah County is leading a project to make one of Portland’s downtown river-crossing bridges earthquake ready. Located on a regionally established lifeline route, it is critical that the Burnside Bridge remain standing after a major earthquake. Four bridge alternatives plus a no-build option were recommended for further evaluation, including:

  1. Enhanced Seismic Retrofit
  2. Replacement: Fixed Bridge
  3. Replacement: Movable Bridge
  4. Replacement: Movable Bridge with Northeast Couch Connection

HMMH is providing noise, vibration, and air quality consulting services on this project. For the noise analysis, the Firm is conducting a highway noise analysis consistent with the requirements of 23 CFR 772 and the ODOT Noise Manual. In addition, we are evaluating construction noise and vibration impacts associated with general construction activities. Greenhouse gas emissions (GHG) are being calculated using the FHWA Infrastructure Carbon Estimator (ICE) and EPA’s MOVES. The Firm also conducted underwater noise monitoring to measure baseline underwater sound levels for use in the project’s Biological Assessment.

The findings of these technical studies are being summarized in the Environmental Impact Statement HDR is preparing for the project.