How structural monitoring keeps excavations safe on Saudi infrastructure projects
Deep excavations for metro stations, basements and tunnels move the ground around them. Monitoring measures that movement early, so the design team can act before neighbouring buildings, roads or utilities are damaged.
IllustrationThe short answer
Before digging starts, a baseline is measured on the retaining walls, the ground and nearby buildings. During excavation, settlement points, prisms, inclinometers, piezometers and other instruments are read at set intervals or automatically, and every reading is compared with trigger levels agreed with the designer. Exceeding a level triggers a defined response, from more frequent readings to stopping work.
What is measured
- Settlement of the ground, roads and neighbouring buildings: levelling points and survey prisms.
- Movement of retaining walls: prisms on the wall crown and inclinometers inside the wall or the ground behind it.
- Groundwater: piezometers and standpipes, especially where dewatering is used.
- Loads in struts and anchors: load cells and strain gauges.
- Cracks and tilt in neighbouring structures: crack meters and tiltmeters.
- Vibration from piling or blasting, where relevant.
Manual and automated monitoring
Manual monitoring uses precise levelling and total station readings on prisms at set frequencies. Automated monitoring uses robotic total stations and data loggers that read continuously and send the results to a web portal, with alerts when a value changes too fast. Busy urban sites and critical neighbours usually justify automation.
Trigger levels and responses
The designer sets trigger levels for each instrument, often in three steps such as green, amber and red. Each step has an agreed response: increase the reading frequency, review the design and construction sequence, add support, or stop work. Monitoring is only useful if the data reaches the right people quickly and these responses are written down before excavation starts.
How YAZ Development helps
YAZ Development provides settlement and deformation monitoring, automated monitoring and geotechnical instrumentation as part of its structural and geotechnical monitoring services in Saudi Arabia, using precise total stations and levels, with baseline surveys, scheduled readings and reports.
Last updated: 20 October 2026 · YAZ Development
Common questions
When should monitoring start?
Before excavation, so a baseline is recorded while the ground and structures are undisturbed. Without a baseline, later movement cannot be measured reliably.
How often are readings taken?
The monitoring plan sets the frequency; it usually increases as the excavation deepens or when a trigger level is approached. Automated systems read continuously.
Who sets the trigger levels?
The design engineer, based on the expected movements and the sensitivity of nearby structures and utilities. The surveyor measures and reports against them.
More guides
- How to set up survey control on large construction projects in Riyadh Establish a primary network of stable monuments, observed with static GNSS and tied to the Saudi national reference frame (KSA-GRF17), adjust it by least squares, then densify it with total station traverses and precise levelling close to the work areas.
- Construction surveying and setting-out for infrastructure projects in Saudi Arabia Construction surveying transfers the design onto the ground and checks the result: it covers control checks, setting-out of alignments and structures, levels, as-built surveys and survey records for quality control.
- How accurate is 3D laser scanning for construction, and how to choose a provider Modern terrestrial scanners measure single points to a few millimetres at short range, but project accuracy depends on registration, ties to survey control, range and surface.
- The benefits of GIS in large-scale urban development in Saudi Arabia GIS gives a large development one shared, location-based source of truth: survey, drone, utility, design and asset data in a single coordinate system.
- Scan to BIM vs a traditional measured survey: which one does your project need? A traditional measured survey records selected points and dimensions and suits simple spaces and small scopes.
- GPR utility detection before excavation: how it works and what to expect A utility survey starts with existing records, then sweeps the area with electromagnetic locators for metallic services and scans it with GPR in a grid to find metallic and non-metallic pipes, ducts and voids.
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