A properly crafted plan for monitoring sound and vibration makes it possible for universities to carry out construction projects near buildings that house extremely sensitive equipment without significantly disrupting research.
New ultra-sensitive equipment used in imaging, diagnostic and research laboratories may be particularly susceptible to noise and vibration disturbances, which have led to potential interference in an increasing number of research fields. Noise and vibrations caused by construction or maintenance projects, even if imperceptible by building occupants, may have the potential to disturb research and animal-care facilities. In many instances, critical measurements or experiments must operate without interruption for weeks or months at a time, and construction-related disturbances cannot be tolerated without risking tens of thousands of lost research dollars and much loss of time. At the same time, new construction, renovation and repair work must be able to continue in and around university campuses.
Noise and vibration monitoring and testing, in conjunction with planning and administrative controls, have been shown to be effective in enabling construction to move forward compatibly with even the most sensitive ongoing campus research activities.
Noise and Vibration Measurement Systems
Most construction projects, even those that have no impact on sensitive equipment, are required to adhere to specified limits on the vibration and noise at and near a work site. Many are bound by regulations that limit the noise that can be emitted to the surrounding community and require measured proof of compliance. When work is being done near existing buildings, vibrations are monitored routinely to avoid structural damage. However, the typical noise and vibration measurement systems that generally are used to deal with these issues are not precise enough to resolve the relatively small disturbances that can affect sensitive equipment. Disturbances that can play havoc with sensitive equipment often are several orders of magnitude smaller than those that can cause even the slightest structural damage or that can be felt by the most sensitive persons.
Advanced instrumentation and monitoring systems can accurately measure the extremely small disturbances of concern to sensitive laboratories.
Vibration-measurement systems play a crucial role in developing the plans and administrative controls for minimizing disruptions to research and construction activities.
For planning purposes, education institutions may find it useful to determine which pieces of construction equipment may be operated near a sensitive facility and at what distances from concerned areas without resulting in vibration or noise levels that exceed the relevant criteria. This information will enable construction managers to plan efficient equipment selection and scheduling.
The desired data may be developed prior to breaking ground by measuring the noise and vibration resulting in sensitive spaces near future construction projects while actual construction equipment is performing representative activities at the work site.
The City College of New York (CCNY) has employed preconstruction testing in relation to construction of a new science building on its Upper Manhattan campus. The New York Structural Biology Center (NYSBC) is situated next to the building site, and researchers at NYSBC were concerned that nearby vibrations from rock excavation during construction might adversely affect the operation of sensitive equipment, such as electron microscopes and Nuclear Magnetic Resonance systems.
Monitoring systems were installed in the NYSBC to measure the vibrations produced by construction activities, such as jackhammering, hoe-ramming and blasting. The test data were used to calculate the vibrations expected during the actual construction of the new science building.
This measurement program enabled researchers at NYSBC to understand when (or whether) their items of sensitive equipment would be affected by the construction activity.
Valuable planning information can be gained from such preconstruction testing.
In some cases, it is desirable to monitor noise and vibration in sensitive facilities continuously during the construction process. For example, laboratory managers have been increasingly interested in documenting the environmental conditions in vivaria over a long term, because changing patterns of sounds in animal research laboratories have been linked to adverse physiological effects in certain species. Researchers also often are interested in determining whether extraneous events may be responsible for some spurious data.
The availability of real-time information from continuous monitoring in laboratories makes it possible to have appropriate personnel notified immediately if vibrations or noise from a construction activity exceeds a threshold limit in an area of concern.
For this purpose, modern monitoring systems rely on Internet connections to send e-mail or text-message alerts when specified limits are exceeded. Such systems also permit all interested and authorized personnel to monitor measurements remotely, to download data, and to control the data monitoring system.
Brush is a senior consultant in the noise and vibration group at Acentech Inc., Trevose, Pa., an acoustics, audiovisual systems design, and vibration consulting firm. He can be reached at [email protected].