Monitoring, Instrumentation and Testing
CGL designs and installs monitoring systems for various geotechnical and geoenvironmental purposes including groundwater and gas monitoring and sampling, surface water and ground movement measurement.
During ground investigation works our engineers design and specify gas and groundwater monitoring standpipes to specifically meet the requirements of the conceptual site model and to reflect the conditions identified. Our experienced engineers and monitoring technicians carry out monitoring or sampling, equipped with the latest equipment for gas flow, concentration and water monitoring to current specifications. Groundwater sampling is undertaken using a variety of methods appropriate to the investigation purposes, including low-flow methods with in-line real-time measurements of various parameters. Gas sampling can also be undertaken by CGL where a specific risk is identified.
CGL maintains a close relationship with a number of geotechnical and contamination testing laboratories who provide us with UKAS and MCERTS accredited testing across the full spectrum of soil, gas, groundwater and leachate tests. Reliability and quality of service is paramount, so alongside our standard approved supplier qualification, CGL also independently audits testing on a periodic basis to ensure the highest standards are maintained. The provision of digital data is critical and we are able to supply all factual results in both AGS 3.1 and 4.0 to ensure easy integration into client systems and BIM.
In collaboration with our approved supplier surveyors we are able to set out and monitor grids of settlement plates and rods to provide a robust confirmation of modelled ground movements following major earthworks projects. More advanced ground movement monitoring through the use of Vibrating Wire Piezometers (VWPs), typically in sensitive ground conditions before and during loading is a particular area of expertise. Similarly, construction monitoring through various methods – including target monitoring, vibration and strain gauges – can be employed to provide appropriate monitoring of sensitive structures including real-time where required.
In-situ testing for geotechnical purposes, typically classifying underlying soil conditions or verifying completed earthworks activities, is undertaken throughout CGL projects using all standard methods. Similarly, in-situ testing for contamination purposes using tools such as PIDs (Photo Ionisation Detector), FIDs (Flame Ionisation Detector), XRFs (Xray Flourescence), and the Petroflag systems enables CGL to properly assess the site risk in terms of contaminants present, even where olfactory evidence is not present.