Transportation Noise and Vibration Control

• Long term and short term noise and vibration monitoring
• Road traffic noise study
• Railway noise and vibration study
• Construction noise and vibration study
• Traffic and construction noise control
• Noise barrier design
• Calculate noise contours
• Prepare the noise part of NEPA/CEQA report
• Noise and vibration control in buildings near roads and railways

Commerce Ave Traffic and Construction Noise Study for Caltrans – We prepared a noise study for a new road connecting Willow Pass Road and Concord Avenue in the City of Concord. The study included traffic noise monitoring and predictions, noise impact on residential and office buildings, noise barrier calculations, and construction noise prediction and mitigation.

330+335 Berry Street Road and Railway Noise Study – This project included two 4-story residential buildings with a total of 131 condominium units in San Francisco. The closest building is 150 feet from railroad tracks and 50 feet from Highway 280/King Street. We were responsible for all acoustics and vibration issues.

Gladstone Building Railway and Construction Vibration Study – This is a 6 story concrete building with vibration sensitive research tools. The building is 250 ft from a railway and 80 ft from a construction site in Mission Bay. 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 when it was deemed necessary.

Aspen-Pitkin County, CO Airport Noise Study & Columbus, OH Children’s Hospital Helipad Noise Study – In these two projects, we predicted noise levels from airplanes and helicopters, evaluated effects of various noise mitigation strategies, and then predicted post-mitigation noise levels. These were compared with applicable noise criteria.

Environmental Noise Monitoring in Phoenix – To establish the baseline ambient noise levels around a Motorola manufacturing facility, Mei Wu conducted continuous simultaneous noise monitoring at 12 locations for 10 days.

Floor Vibration Analyses

Mei Wu Acoustics has worked on many projects where special floor design is required for vibration-sensitive equipment. Typical work includes establishing vibration criteria, predicting floor vibration, and providing recommendations on floor design. The following are descriptions of three projects with very different vibration requirements.

Stanford Hospital Clinical Laboratory Buildings

This project was to move microbiology, molecular pathology, virology and other laboratories into two existing two-story buildings. The existing buildings were originally designed for offices and have a maximum vibration of 20,000 micro-inches per second. But the vibration sensitive equipments, such as microscopes, require a vibration criterion of 2,000 micro-inches per second. Mei Wu Acoustics evaluated the existing floors, explored vibration reduction options and recommended cost-effective solutions to achieve the vibration criteria without major changes to the building structure.

UCSD Mayer Hall Addition and Renovation

This project includes a major renovation of a 90,000 square foot existing building and an addition of a 79,000 square foot new wing. Vibration sensitive research equipment will be used in this five story building. Mei Wu Acoustics established vibration criteria for the sensitive equipment, conducted floor vibration predictions, and worked with the structural engineers on floor designs.

409 & 499 Illinois Street, San Francisco

This is a shell and core building composed of two five-floor towers over two levels of parking. The total leasable space is 450,000 square feet. The target tenant is a mixture of office and life sciences with an emphasis on biotech laboratories. The floor design has to be suitable for biotech laboratories and cost-effective. Mei Wu Acoustics established FEA models for the building and studied vibration impact from footfalls on corridors, from vehicles on parking levels, and from rooftop mechanical systems. Based on the study, Mei Wu Acoustics provided recommendations for floor design.

Sample Projects in Floor Vibration