M.C.H. (Martijn) van Delft, M.Sc., Allnamics, has made his mark on many aspects of geotechnical engineering. He is an expert in the field of vibration monitoring and has contributed to the new Dutch SBR-A:2017 guideline, amongst others. We spoke to Martijn about measuring nuisance to people in buildings and measuring at long distances.

Nuisance to people in buildings

• You've done vibration measurements with Omnidots to monitor nuisance to people in buildings. Can you tell us anything about that?

"In the webinars, I speak about the SBR-B measurements I did with Omnidots. We then measured nuisance to people in buildings caused by passing trains.

In a Dutch village, people felt vibrations day in and day out. These vibrations were caused by nearby passing trains. Normally, the vibrations are so severe in that area that people in the village actually wake up during the night from the sounds of passing freight trains. We then monitored these vibrations and came to the conclusion that the vibrations were actually unacceptable. However, how do you solve that? During the disturbance measurements, we saw that very intense vibrations occurred at night, for up to 30 seconds. People were literally shaken out of their beds, so to speak. It is often not possible to stop trains on a particular route. Therefore we had to conclude that we had to accept the current situation as it was, as long as the situation didn't become worse. We mounted an Omnidots SWARM on a Base Plate in a walk-in closet because this was not an area where someone would often walk. We filtered out the ordinary vibrations, and after measuring for some time, analyzed the measurement results."

"I think Omnidots is a top product at the moment, especially in its ease of use."

Monitoring a project 7000 km away

• Another project is very adventurous. We’ve heard that you are measuring vibrations from 7000 kilometers away. Can you tell us about that?

"Yes, we are based in the Netherlands and we are conducting measurements for a client in Saint Lucia. Saint Lucia is an independent island nation in the Caribbean. The island, which has a land area of 606 km² and 166,487 inhabitants, is located 7,000 kilometers from the Netherlands. On Saint Lucia, 3000 piles need to be driven into the ground.

We had SWARMs sent to our client on the site and they installed them. There is no specific training required, so the customer could easily do this themselves. We monitor the measurement data from our office in the Netherlands. The measurements are to prevent damage, because there are buildings nearby. We measure according to Dutch guidelines- so according to SBR-A. I think Omnidots is a top product at the moment, especially in its ease of use."

With Omnidots you save money

• How is your experience with the Omnidots products?

"If I had used equipment other than the Omnidots sensors in these projects, I probably would have spent much longer processing the data and taking the measurements. In terms of operations, I think Omnidots is the ideal product on the market right now.

With Omnidots, you save a lot of money.

“I am very happy with my Omnidots products at the moment.”

When I start a project, I grab my SWARM and SWARM Battery and check that the battery is full. I put the items in the case and drive away. If I use a product other than Omnidots, I have to turn on the product, check that the battery is full or replace loose batteries. Then I have to set all the settings of the device correctly. Then I have to make sure that I have the right software with the right licenses, which sometimes causes problems. Sometimes you have to pay extra for licenses, so you keep spending money and you don't want to do that. With Omnidots I don't have to worry about the settings; I set them online after I switch on the SWARM on. Also, with other vibration monitors, I have to make sure the geophone is hanging straight and I have to mount the device properly with a special bracket. Not everyone can do this. The ease of use is not as good as with the SWARM. With Omnidots I only use one screw, I screw on the SWARM, it aligns itself and it hangs.

"With Omnidots, I don't have to worry about the settings; I set them online as soon as I turn on the SWARM."

It's also much simpler in terms of business management. You don't have time-consuming hassles with software versions, because Honeycomb is always accessible online. I am very happy with my Omnidots products at the moment.

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The advantages for Martijn van Delft

For Martijn van Delft, these are the biggest advantages of working with Omnidots:

• Ease of use
• Money Saving
• No hassle with software licenses and the benefits of online platform Honeycomb
• Calibration data is immediately available
• Easily adjustable daily and weekly reports
• No hassle with data files/data readout etc.