Rail Monitoring

DYWIDAG measures the railway as well as instrumenting it.

Our surveyors and monitoring technicians are employed directly by DYWIDAG and are available 24/7, providing the advantage of the baseline survey before works, the monitoring during them, and the final survey afterwards, delivered by one team, and sitting alongside the sensor data in Infrastructure Intelligence.

On the track, we deliver track alignment assessments, precision levelling to <0.5mm, platform gauging and clearance analysis, and overhead line height and stagger. On structures and earthworks, 3D laser scanning and point cloud surveys record the full geometry of an asset, digital imaging correlation and structured deflection surveys measure how it responds under load, and condition and dilapidation evaluations record its state before and after works. Where readings are required more often than a survey visit allows, automated total stations measure prisms on a programmed schedule with no staff on or near the line, and InSAR satellite data adds millimetre-level ground deformation along whole routes.

• Track alignment assessments, platform gauging and clearance analysis, and overhead line (OHL) height and stagger measurements
• Automated total stations giving survey-grade three-dimensional displacement on a programmed schedule, with no staff on or near the line
• Surveyors, monitoring technicians and rope access teams employed directly by DYWIDAG
• Sub-millimetre precision levelling to <0.5mm, and topographical surveys using GPS and total stations
• High-definition 3D laser scanning and point cloud surveys, with targeted patch scanning
• Digital imaging correlation, structured deflection surveys, and condition and dilapidation evaluations
• InSAR ground deformation along a route, millimetre-level, bi-weekly updates, with historical analysis and processing for vegetated areas

Where an embankment, cutting or retaining structure is moving, or is suspected of it, DYWIDAG installs and reads the borehole instrumentation that establishes the depth, direction and rate of that movement, and proves afterwards whether sheet piling, reprofiling and/or drainage has stopped it.

The same instrumentation characterises the ground before a scheme is designed and shows during works that any excavation or dewatering beside the line is not affecting the ground profile.

Inclinometers are the primary instrument supported by piezometers. Installed through the slope into stable ground, they locate the depth of any failure surface and show the magnitude, direction and rate of movement over time. In-place inclinometers report automatically through data loggers and are alarmed against agreed thresholds, so acceleration on a developing failure surface is identified as it happens. Manual probe surveys provide the baseline, with independent verification and periodic monitoring. DYWIDAG's own field teams travel the rail network, reading inclinometers and piezometers on a programmed cycle, so a route's whole earthworks portfolio is managed by one team. In Infrastructure Intelligence, boreholes are presented in three dimensions along the earthwork, showing displacement with depth and its development between readings, alongside the surface monitoring for the same slope:

In-place inclinometers reporting automatically through data loggers, alarmed against agreed thresholds, with manual probe surveys for baseline and verification

• DYWIDAG's own field teams reading boreholes with manual inclinometers and piezometers across the network on a programmed cycle
• Three-dimensional borehole views in Infrastructure Intelligence, showing displacement with depth and its development between readings
• Depth of the shear surface, and the magnitude, direction and rate of movement, from cumulative displacement against a fixed toe in stable ground
• Piezometers for pore water pressure. Settlement and extensometer installations for vertical movement
• Ground characterisation before design, and monitoring of excavation and dewatering beside the line during works
• Ground, surface and track geometry monitoring for the same earthwork visible in one project