Californian break-through for efficient
noise and vibration monitoring

BART commuter trains are of vital importance to business and people in the San Francisco area. Now an extension toward Silicon Valley is added.

BART provides the commuter train connection between the three cities of San Francisco, Oakland and Freemont. Recently construction work started for the missing extension to San Jose, the “capital” of Silicon Valley. The first 10-mile phase Freemont – Berryessa is projected to carry 23.000 weekday commuters when in operation by 2017, thus relieving regional freeways from notorious congestion.

A cost-reducing monitoring system

The success of ASC is in large part due to the cost reducing and efficiency-enhancing INFRA measurement system and the distinctive features of its reporting facility INFRA Net. Allowing a small consultant company to handle the 10-mile alignment, the high number of monitoring stations and the public outreach required.

– We have used the INFRA system before on a couple of projects in the area, for example The Sunnydale Tunnel Extension in San Francisco, says Dr. Oyenuga.

– INFRA offers the unique ability of using the same bus cable and data logger for uploading both noise and vibration data. This provides savings when noise and vibration monitoring are coincident. Moreover the digital instrumentation provides additional accurate data and more stable instruments than analogue alternatives and requiring less maintenance.

– INFRA automates the entire monitoring process which means that reports are easily generated, easily achievable and easily retrievable.

A means to improve contractor efficiency

– The INFRA system also offers several advantages to our customers, including real-time noise monitoring. This enables the contractor to provide abatement measures on-the-fly during construction, minimizing disturbance to neighboring residents and businesses, Dr Oyenuga continues.

– Currently, we set up thresholds/ trigger levels at each monitoring station. The thresholds are based on the results of a baseline study of ambient noise levels that we conducted prior to the start of construction. If the thresholds are breached during construction, notification protocols are automatically triggered, and the relevant text messages are sent to a pre-defined list of stakeholders, informing them of the specifics of the breach.

– Our INFRA is performing as expected and we are receiving excellent support from the Swedish system producer Sigicom with some scheduled software developments the system will provide facilities that sharpen its competitive edge even more, Dr. Oyenuga concludes.