Geotechnical Monitoring Systems: The New Multi-Parametric DMS Columns - The Importance of the Testing in Lab and in Field For Reliability and Data Interpretation in the Early Warning Applications-Paper

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The paper examines how multi-parametric geotechnical monitoring columns can improve continuous monitoring and early warning for landslides, excavations, and engineering works. Unlike conventional inclinometers, which typically monitor only limited depth intervals and depend on grooved casing, modular columns can provide real-time deformation measurements along an entire borehole, potentially hundreds of metres deep. They can also accommodate additional instruments, such as piezometers, strain gauges, and accelerometers.<br /><br />The authors emphasize that reliable data depend on more than the accuracy of individual sensors. Long columns contain many joints, and small assembly errors can accumulate into substantial sensor-axis misalignment, or “spiralling.” This can distort both the measured displacement magnitude and its direction, undermining interpretation and early-warning decisions.<br /><br />To address this risk, C.S.G.’s DMS system uses specialized mechanical assembly equipment to align joints and individually calibrates inclinometric sensors on a biaxial rotary table. After assembly, the complete column is tested in a temperature-controlled facility. In the “ArcTest,” the column is installed in a borehole with a known inclination; software compares its measured profile with the known borehole geometry, identifies phase shifts, and applies alignment corrections. These procedures can verify and improve overall column accuracy before installation.<br /><br />The paper concludes that multi-inclinometric and multi-parametric columns can support monitoring of deep and complex ground conditions more comprehensively than traditional systems. However, they must be treated as integrated instruments—not merely chains of sensors—and manufactured, calibrated, and tested with rigorous procedures. Accurate alignment and full-column testing are essential to ensure trustworthy displacement data and effective risk mitigation.

Keywords

geotechnical monitoring

landslide early warning

multi-parametric columns

inclinometer

borehole deformation

real-time monitoring

sensor alignment

spiralling error

ArcTest calibration

ground deformation