2020-02-17

Location, Location, Location

The major challenge is location

Monitoring the environmental impacts arising from construction activities is fast becoming common practice for major projects in the UK, as it should be. With this comes the drive to ensure the monitoring system is fit for purpose, proportionate and cost effective.

Increasingly projects are seeking combined monitoring stations covering noise, vibration and particulates from one unit. This type of system can bring significant cost savings but it is not without its challenges. When considering this style of system it is important to ensure that the purpose of the system is not lost and the data is reliable.

The major challenge faced by an integrated system is location. To better understand this you must understand who or what you are seeking to protect by monitoring.

Noise: typically measured to ensure that the function of the receptor (typically residential or commercial) is not compromised by excessive noise. The ideal monitoring location is at the point of entry to the building. Where this is not practical it is possible to correct the measurement data based on the position of both the noise source and the receptor relative to the monitoring location. This is not necessarily simple for construction where the noise sources are highly mobile rather than static – in practice you are likely to both over and under predict the levels over the course of a day.

Vibration: normally measured to manage the risk of both health effects and building damage. Vibration should be measured at the point of interest which is either a location representative of the building foundations/structure in question or at the point within the building where the occupant(s) may be exposed to vibration. Monitoring at locations not covered above has multiple challenges. The prediction of vibration propagation from one location to another is difficult and relies on knowledge of the underlying ground conditions. Modelling of vibration propagation is complex and costly. There is a real risk the vibration levels at the receiver are above those predicted, which could lead to significant issues should building damage occur.

Particulates: standard advice states site boundary monitoring at a minimum of two locations (upwind and downwind of the prevailing conditions) should be undertaken. Particulate monitors should be located with an unobstructed view of the sky which typically rules out façade locations.

As you can see although it is possible to measure these three parameters at a single common location it may not be appropriate to do so.

In reality, what is most important is reliable data presented in an accessible format. There are combined systems which allow you to utilise a single data logger and multiple sensors separated by large distances, such as Sigicom’s cabled system where noise, vibration and dust can be monitored on a single logger and sensors can be up to 800m from the data logger.  However, where the site logistics restrict this type of system then stand-alone systems such as the INFRA C22 – vibration monitor are ideal as they still provide the same high quality data to a common integrated cloud platform.

Combined systems have their benefits and a place in the monitoring ecosystem but it is essential that they are utilised appropriately and not to the detriment of the accuracy and reliability of the data collected. There is a real risk (both financial and contractual) introduced by monitoring in the wrong location and the kicker is the magnitude of this risk is likely to be unknown and unmanaged.

If you would like to understand more about monitoring, please get in touch.