The following are typical acoustical and vibration issues associated with infrastructure projects:
Transportation SystemsWe are monitoring construction noise at 6 community stations and 4 construction site stations. The noise data are published wirelessly on a website accessible to the engineers through a password. When the noise exceeds the criteria, an alarm is sent to the engineers within seconds via emails and text messages. Audio recordings of the exceedance events are available on the website to allow the engineers to listen to the noise and identify the sources within minutes. All noise levels and exceedance audio recordings are archived automatically. The nighttime noise levels at the community monitoring stations are published daily at 1 pm at a public website. Please feel free to take a look at the published data (goto Construction > Noise Data). http://www.caldecott-tunnel.org/index.php/construction/noise-data
For more information about the wireless system click here.
This project predicted future noise levels of a new road connecting Willow Pass Road and Concord Avenue based on traffic data along with our own noise survey. Required noise levels for nearby residential and office buildings were met.
This project was a 173 acre luxury resort. We conducted noise surveys, calculated the noise impact from nearby noise sources and developed noise contours.
We predicted the noise impact on multifamily housing buildings to be constructed next to Interstate 280 and provided exterior envelope construction recommendations to meet code requirements.
We predicted the noise impact of the airport on nearby residential houses, evaluated the effects of different noise mitigation strategies, and calculated post-mitigation noise levels.
We predicted the noise and vibration impacts of the rooftop helicopters on the medical center and provided recommendations.
Public WorksWe conducted an overnight noise survey, predicted equipment noise impact to adjacent residences, and recommended noise mitigation details to meet the local noise ordinances.
We conducted vibration measurements and calculations to evaluate the vibration impact generated by proposed pile driving site that would be adjacent to an existing research facility. We predicted vibration levels on the laboratory floors based on the vibration levels of the sources, vibration attenuation through soil, building foundation and laboratory floor structure. We compared predicted vibration levels with the vibration criterion and concluded that for 95% probability pile driving vibration will not exceed the vibration criteria.
In this project, we worked with a generator enclosure manufacturer in Illinois to design a special enclosure for a 1,500 kW emergency generator. We were able to meet the most challenging design criterion of 50 dBA at 23 feet.
Information TechnologyWe engineered cost-effective noise mitigation solutions to meet noise ordinances at property lines. We also conducted vibration studies to meet the ASHRAE floor vibration criteria in the server area. The project included numerous MEP systems including emergency generators, chillers, cooling towers.
We measured sound levels at extremely low frequencies, detected peaks as low as 8 Hz, identified noise sources, and developed a noise mitigating strategy with the design team.