Foire aux questions

As long as the vibrations remain within the limits defined by the applicable norms (German standard DIN 4150), they will not have any impact on the buildings. The trucks have a precise vibration programme to suit the different areas of the city and the buildings they encounter. Safety distances will be defined according to the acquisition zone, and each vibration will be monitored by a measuring device placed close to the nearest buildings. The generated vibrations are subject to the same regulations as those that apply to construction sites, for example. The magnitude of these vibrations will be of the same order as those induced by a vibrating compactor during roadworks, or during foundation excavations. However, the duration will be much shorter. These operations will be carried out in strict compliance with environmental standards, particularly in terms of soil protection.

The sound emitted by one of these trucks is comparable to that of a refuse collection vehicle. The waves emitted by the truck are brief (about 2 minutes every 20 metres) and the perceived noise level will depend on the distance at which the truck is being driven. At any given point in an urban zone, the noise should not exceed 15 minutes.

The orange boxes are receivers (“geophones”) that collect the vibrations generated by the vibrating trucks and the resulting reflections from the subsoil. If geophones are missing along the route, less data will be collected as the trucks only drive once over each of the designated spots. This would jeopardise the quality and reliability of the results and overall understanding of the subsoil required to exploit geothermal energy in the future.

En cas de questions, vous pouvez vous adresser par e-mail à info@seismik.lu ou par téléphone au 2846-4529.

During the preliminary phase, markings (made using biodegradable paint) define the location where the measuring devices (geophones) will be placed. The ground markings, stakes and tape that have been put in place will be removed/cleaned after the trucks have passed and the sensors have been collected, at which point our project will also come to an end.

If you are standing close to one of these vibrating trucks, you may feel some vibrations from the ground, particularly at low frequencies, similar to those caused by a refuse collection vehicle. However, beyond a certain distance (>10 m), the vibrations reduce to such a low level that they can hardly, if at all, be physically perceived (depending on the geology of the surface terrain).
Although no studies have been done to assess the impact on animals, we have had no reports of any problems during the dozens of seismic surveys we have carried out in the centre of stables and cattle farms.

What is more, during the project preparation phase, we always take care to inform any relevant centres that we are going to be working nearby, as for instance the wildlife care centre in Dudelange, which happens to be along the route of our project.

The work will be carried out outside peak traffic periods (09:00 – 16:00). It is likely that our operational phase will slow down traffic as we pass through town, and possibly even in the surrounding areas, but we will have a dedicated workforce and systems in place to ensure that traffic flows smoothly. On one-way streets, where traffic is expected to be heavier, no-parking and road-closure signs will be put up for a maximum period of one hour, with the help of the local authorities and their traffic/technical services. Notices to this effect will be issued by the local authorities.

The campaign is due to start on the 15th November 2023. The trucks will operate in groups of three (outside towns) or just the one (inside towns), during the day between 09:00 and 16:00, from Monday morning to Saturday afternoon. The precise dates on which the trucks will operate will be communicated to the local authorities a few days before the start of the work. A map showing the progress of the project is available on this website.

A certain amount of noise is to be expected during the day, caused by the passing trucks (engines) and their vibrations emitted into the ground, but this will only last a few minutes. As we work during the day, the day-to-day outside noise will drown out the sounds generated by our engines. More specifically, the trucks will stop for around 2 minutes at each monitoring point. In total, 15 to 20 minutes of disturbance can be expected in populated areas. In terms of volume, the trucks are likely to generate 80 dB at a distance of around 8 m, which is roughly equivalent to the noise of a refuse collection vehicle. There will also most likely be some acoustic effects related to the vibrations in the floor/walls that may ripple through the buildings/homes. However, these will be very limited as the intensity of the vibrations will be reduced in populated areas. The intensity of the vibrations corresponds to the limit values specified in DIN 4150, which have been determined on the basis of tests in your neighbourhood.

The hunting season in Luxembourg opened on the 10th September. Our route is mainly along national roads and paths, and as far as the hunting zones in the region are concerned, it will be too far away to affect any hunting activities.

For the feasibility of a geophysical field study, it is important to record and identify the exact locations of underground networks and infrastructures (high/medium and low pressure gas, drinking water, wastewater and rainwater, electricity, telecommunications, etc.). We obtained information on these networks from the various operators and providers in order to integrate them into our route and establish safety distances according to the type of pipes (type of networks + materials used). Thanks to the safety precautions put in place and the use of a vibration mode that makes it possible not to resonate with these networks, this will not pose any risk.

The PPV meter is a compact device that can be used to monitor the vibrations generated by trucks in real time. It is important to have the option of placing it near structures for pre-emptive purposes. Around buildings and other sensitive structures, the real-time particle velocities (PPV) are monitored and if a threshold value exceeds the value defined during our test phase, the vibration is stopped immediately. These tests, which are carried out prior to the measurements, are supervised by a DIN 4150 certified company.