Mei Wu Acoustics

The following are typical acoustical and vibration issues associated with infrastructure projects:

Projects > Environmental Noise and Vibration

Our work with infrastructure projects has included the full range of environmental noise and vibration prediction and mitigation design. The following are a few recent infrastructure projects separated into the categories of Transportation, Information Technology, and Public Works.

Transportation SystemsTransportation Systems

Caldecott Tunnel Fourth Bore, CA

We are monitoring construction noise at six community stations and four 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.

Traffic Noise Study for Caltrans, Concord, CA

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.

Noise Contours at Montage Resort, Cabo San Lucas, Mexico

This project was a 173-acre luxury resort. We conducted noise surveys, calculated the noise impact from nearby noise sources and developed noise contours.

Traffic Noise Impact to Residents on Berry Street, San Francisco, CA

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.

Airport Noise Study, Aspen-Pitkin County, CO

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.

Rooftop Helipad Noise and Vibration Study for Medical Center, Kuawaii, HI

We predicted the noise and vibration impacts of the rooftop helicopters on the medical center and provided recommendations.

High-Tech Noise and Vibration MonitoringHigh-Tech Noise and Vibration Monitoring

Gladstone Building, San Francisco, CA

This six-story Mission Bay research building houses vibration sensitive tools and was 250ft and 80ft from a construction site and railway respectively. Based on site vibration measurements and structural calculations, we predicted the vibration from the railway and construction activities transmitted through ground to the building foundation and columns to the laboratory floor. We recommended vibration mitigation where necessary. The vibration study cut construction costs by allowing pile driving to be performed near the Gladstone building.

BioMed Realty, San Diego, CA

We conducted a construction vibration study to predict the effect of demolition activities next to a sensitive BMR tenant. During demolition a permanent vibration monitoring station was installed within the sensitive laboratory building to maintain a full ground vibration record for the duration of construction. The monitoring results were analyzed to yield daily spectrum percentile distribution and overall vibration level versus time.

HGST, San Jose, CA

We conducted ground vibration monitoring at HGST electronics manufacturing facilities to characterize current environmental vibration exposure prior to the renovation of a facility in South San Jose. We studied the vibration impact from railway lines, roads, and other vibration sources.

Internet Colocation Data Center, Newark, CA

We 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.

Low Frequency Noise Measurements at Seagate, Fremont, CA

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.

365 Main Data Centers

Equinix Data Centers

Adobe Office Data Center

Brocade Data Center

Carlson Data Center

Cisco Call Center

SPD Data Center

MEP System Noise MonitoringMEP System Noise Monitoring

Bloom Energy Fuel Cell Sound Study, California

We provided acoustical analyses for the installation of fuel cells in many locations in California. We monitored the existing ambient noises, calculated the noise impact from the fuel cells, compared it to the local noise ordinances, and provided noise control recommendations if necessary. We also worked with engineers of Bloom Energy to measure the sound power output of the energy cells.

Water Treatment Facility Noise Study, Healdsburg, CA

We conducted an overnight noise survey, predicted equipment noise impact to adjacent residences, and recommended noise mitigation details to meet the local noise ordinances.

Vibration Impact of Pile Driving on Lab Buildings, San Francisco, CA

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.

Kentfield Pump Station Noise Study, Kentfield, CA

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.

Zone 7 Water Agency Sound Tests, Livermore, CA

Vacaville Water District, Water Pump Noise Control, Vacaville, CA

Outdoor Event Sound MonitoringOutdoor Event Sound Monitoring

Our sophisticated monitoring system was developed not only to record live sound information in a variety of ways but also to provide live updates when sound overages are reached. We can use this data to determine the amount of sound that exists at specific locations in relation to the noise sources.

Insomniac Concert and Festival, Los Angeles, CA

This large music festival is a major event in southern California. We established noise criteria based on the ambient sound levels and the maximum allowable levels determined by the San Bernardino Residential Code. We developed a sophisticated noise study and monitoring sound for three days in several locations and relaying this information to the production team and helping them to deliver an extraordinary audience expectation while meeting the noise code and reducing noise impact to the neighbors.

Greek Theatre Sound Level Measurement, Los Angeles, CA

Live Nation used our consulting and monitoring services to determine the sound levels during a concert that may impact the adjacent residential properties. After taking ambient measurements in three locations during a concert and while there was no show in process, we analyzed the noise data and reported a detailed noise description of each monitoring location.

Kimson Meditation Center , Watsonville, CA

This meditation center has large events that attract thousands of people and the noise that comes with a crowd. We conducted sound measurements in three different locations during one of these events to monitor the noise at the centerís property lines. We found that the noise emitted did not violate local noise codes.