Monitoring Construction Vibration – A Better Alternative

Some sites require a more stringent level of control.

The usual routine may not adequately protect the owner.

Monitoring vibration near construction sites is commonly done by contractors and their subs. However, their goal is usually to prevent damage to structures, not to protect sensitive processes, procedures and equipment that may exist in adjacent buildings. To fill the gap between traditional and advanced monitoring needs, ESI Engineering has developed a unique monitoring system which we are excited to introduce.

Possible disturbances

Hospital operating rooms, MRI and CT imaging equipment, university research laboratories, microelectronic manufacturing, and critical data centers are examples of sites that are particularly sensitive to construction vibration.

Sources of construction vibration can include truck traffic, soil compaction, rock blasting, drilling, excavation, demolition, pile driving, and vibratory sheet piling. Such operations can be ongoing for several weeks or months and unfortunately vibration can propagate over long distances through the ground to adjacent buildings.

What is the usual process for vibration monitoring?

Usual practice is to measure the peak particle velocity (PPV) with instrumentation like the Instantel Minimate (TM). This equipment does an excellent job monitoring vibration levels on the order of 0.12-0.5 in/sec PPV to prevent damage to buildings. Unfortunately, a sensitive microscope used in surgery will be disturbed at vibration levels around 1,000 times lower. To protect sensitive occupancies, vibration monitoring equipment and methods need to be more sophisticated than the techniques used to measure PPVs.

The risks of not using a monitoring approach tailored for sensitive occupancies can be obvious. No contractor or facility manager wants to negatively affect patients in hospitals, cause poor MRI images, delay critical research, lower wafer fab yield, or disrupt server operations in a critical data center. Therefore, it is important to understand how the construction site fits into the big picture of its surroundings.

The benefits of advanced remote monitoring are to increase productivity for the contractor while at the same time reduce risk for the owner.

A monitoring alternative to meet strict requirements.

Installation can be made at any site.

A basic installation consists of a computer and data acquisition (DAQ) system connected to small piezoelectric accelerometers. Accelerometers can be mounted to whatever location is vibration critical (like a floor slab, equipment racks or soil). Vibration signals are then transmitted to the DAQ. The installation is quite small (about the size of a desktop computer) and can be positioned wherever the contractor or owner requires with little or no impact to the job site.

 

 

The right information at the right time.

E-mail alerts can be sent automatically to a computer or smartphone the instant vibration levels exceed preset critical levels. These alerts give the contractor and the owner confidence that the construction is not disturbing sensitive operations.

Time histories of vibration levels can be automatically stored or remotely viewed in real-time for documentation or detailed assessment of construction operations. Information from real-time monitoring can help pin-point problems as they occur and allow the contractor to respond quickly.

“The process allowed us to react to changes in the construction process and make adjustments in order to ensure operation of the owner’s data center.”

A customized solution can improve results.

Many jobsites require a special solution to ensure that workers are aware of the impact they are having on vibration. In some cases “traffic lights” have been used to notify excavation operators when they are approaching, or exceeding, limits. This allows personnel to react quickly to protect a nearby sensitive facility.

Who can perform remote monitoring?

A vibration expert who has the latest in measurement technology and the knowledge to interpret the results is crucial. ESI Engineering has both the equipment and expertise necessary to provide a solution for the vibration aspect of your project. Visit our website for more information or contact us directly to discuss your custom installation.

System Capabilities:

• Real time notifications to your computer or smartphone
• Internet accessible
• Compact installation
• PPV/displacement/velocity/acceleration measurements
• Full frequency analysis (narrow band, 3rd octave)
• Overall VdB trend, overall RMS trend
• Time history recordings
• Redundant backup of all logged data
• Custom tailored trigger and alarm functions