Monitoring the surroundings

‘A construction or renovation project is practically never without risk. The work must be monitored with an eye to the legislation and regulations. Monitoring makes it possible to keep the risks of the construction or renovation project under control for the surroundings and in case of claims. SOCOTEC measures vibrations in accordance with the KOMO BRL 5023 assessment guidelines – “Measuring vibrations” and SOCOTEC’s sound-level meters meet the requirements of NEN-61672, Class 1.

The advantage of monitoring the surroundings is that the contractor can carry out the project using a risk-based approach. In addition, this data is very important for handling any damage claims.

Vibration measurement

For almost all projects, work is carried out that causes vibrations. Heavy transport also leads to vibrations that may cause damage in the vicinity. The intensity of the vibrations depends on various factors such as:

The type of work (piling, boring and drilling, demolition, pumping, etc.)
The type of transport and equip,ent (lorries, vibratory plates, pile-drivers, demolition equipment, etc.)
The type of underground and infrastructure (soil structure and soil condition, brick paving or asphalt paving, etc.)
The distance from the source of the vibrations to the neighbouring buildings and structures in the vicinity

Talk to our experts

Frits (G).A. Eppink

Department Coöridnator Accountteam

f.eppink@hanselman.nl +31 264 420460

Ir. Ben van der Kwaak, NIVRE re

Manager Construction & Engineering

b.vd.kwaak@hanselman.nl +31 6 10050480

SOCOTEC conducts its vibration measurements in accordance with the BRL 5023 assessment guideline “Measuring vibrations”. Measuring in accordance with the KOMO BRL 5023 assessment guideline means that all the measurements are carried out in accordance with the highest quality standards. The equipment is calibrated every year. A third, official party tests and checks the measurements carried out. This offers clients certainty and a reliable, high-quality product.

Noise measurement

During building work in inner cities, the area is subjected to construction noise. This can inconvenience those in the vicinity, for example homes, schools and companies. In the Netherlands, only a certain number of decibels of construction noise many be caused for a certain period. The Building Code also indicates that a noise measurement must be carried out for inner city building activities.

SOCOTEC has its own advanced sound-level meters that register the noise level. These meters meet the requirements of NEN-61672, Class 1.

Our measurements are conducted in accordance with the guidelines of the 2010 Construction Noise Circular.

Deformation measurement

With most construction and/or demolition projects, there is a risk that settlement will occur in neighbouring or surrounding buildings and structures, within the activities’ range of influence. This settlement may occur, for example, as a result of vibrations coming from the work, excavation near to neighbouring constructions or pumping at the project location. Settlement in the vicinity can have major, negative consequences for neighbouring constructions and structures.

SOCOTEC can measure the settlement nearby using different types of deformation measurements. Both manually and continuously.

A height measurement is a measurement of the surrounding constructions and/or structures in the Z-direction compared to the Amsterdam Ordnance Datum (NAP). Prior to the work, a single or double baseline measurement is carried out that will serve as the point of reference. This will make it possible to observe any deviations from this baseline during or after the work by repeating the measurement. In this way, it can be determined whether any settlement has occurred.

During work on or near to an embankment, repairs to foundations, work near to tracks or during excavation work, there is a risk of settlement. To monitor any possible deformations to these structures, SOCOTEC can carry out measurements of the X-Y-Z coordinates. This consists of placing and measuring measurement marks (for example stickers or prisms) on the buildings / structures to be monitored. Using a total station, the measurement marks are triangulated, departing from a local coordinate system or the national coordinate system (National Triangulation system).

Surroundings Monitoring

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For more geotechnical monitoring services, monitoring of the surroundings, construction site and groundwater:

See the page on Monitoring the surroundings

Slope measurement

It regularly occurs that our clients execute a project in which a construction pit is built. In most cases, these construction pits are formed by placing sheet pile walls. Horizontal movements and bending of the sheet pile wall can have major, negative consequences for the construction put, but also for the surroundings.

SOCOTEC carries out slope measurements by inserting a digital inclinometer into the ground via slope measurement pipes. Movements can be observed and registered up to a depth of 20 metres.

Standpipe measurement

In many projects, our client have to remove soil (excavate) and/or groundwater (pumping). It is important that the groundwater level remain stable, because too many fluctuations can have negative consequences for the surrounding area. Examples include subsidence, mould, uplift or damage to and deformation of a building’s foundations.

whether the walls and horizontal soil sealing used at the deepest point of the construction pit form a sufficient water barrier when removing groundwater within the construction pit.

Our measuring systems

Fibre optic monitoring is above all interesting when used in long-term projects or long-term investigations into the movement / deformation of structures, constructions or other elements.

Fibre optic monitoring is based on the fact that changes in the length of an optical fibre lead to the properties of light changing when it passes through the fibre or is reflected.

During construction, fibre optic monitoring can be used to chart the behaviour of buildings. In addition, fibre optic monitoring can be used for very long sections of infrastructure to chart deformations over a longer period of time. For example long sections of track, embankment constructions, bridge constructions, but also in the energy sector to monitor cables and pipelines.

Fibre optic monitoring can measure the following parameters: temperature, elasticity, strength and vibrations.

The use of tiltmeters makes it possible to continuously monitor any angular displacement (tilt) of a building or construction in a cost-effective way.

The tilt sensors measure the tilt in both the X and the Y direction. In addition, the sensors are equipped with a temperature sensor. The sensors have an accuracy of 0.05° and the measuring data can be viewed via an online portal.

For less risky work, where does the groundwater level does not need to be constantly monitored, SOCOTEC provides a manual standpipe. The measuring expert of SOCOTEC will lower a plumb line into existing or new standpipes. This is a simple method for determining the groundwater level. This is the baseline measurement.

For complex and risky work (for example in inner cities), it is often necessary to constantly monitor the groundwater level. Automatic gauges are lowered into existing or new standpipes. The meters will provide an update on the groundwater level several times a day. The results are can be followed continuously via an online platform. In this way, the client can react in an adequate manner if the groundwater level changes.

As a contractor, with every project you also have take the surroundings into consideration. In most cases, the surroundings will include neighbouring buildings and structures, where there are always existing cracks. For example in the masonry or plasterwork of homes. To avoid discussions with and claims by the residents, a contractor can opt to place crack width meters, prior to the work that entails the risk.

SOCOTEC has years of experience with carrying out both manual and automatic crack width measurements, thus avoiding many discussions.

For critical cracks or during long-term projects, an automatic crack width meter can also be used. The Ellitrack-L can measure the width of a crack in masonry or a construction component of a building or structure with a resolution of 0.0061 mm. The measurements can be saved at configurable intervals and can also be sent to a web-portal (ElliTrack.nl) at configurable intervals. Via this portal, a chart of the measured data can be viewed and that data can also be downloaded. Alarm limits can be set. If the limits are exceeded, an e-mail or text message is sent. The standard range of the sensor is 25 mm. A maximum of 2 sensors can be connected.

Manual crack width meter

When carrying out work that causes vibrations, there is a risk that existing cracks in or on homes can grow bigger or wider. This is easy to monitor by placing a crack width meter. The expert observes these cracks during the execution of the architectural survey and, in consultation with the client, will place a crack width meter across the crack. After placing the crack width meter, a photo will be taken to establish the baseline situation. For any subsequent registrations, or if there are complaints from residents, we will assess the cracks again using a new photo to determine if there is any difference. This data can be used when carrying out a causality assessment.

Want to know more about our Services ? Contact us

f.eppink@hanselman.nl