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Excavations and tunnels, watched beside every neighbour.

A deep excavation or a tunnel drive under a city moves the ground around it, and the buildings, pipes and railways on top. Automatic total stations, GNSS, inclinometers, piezometers and vibration sensors report to one record the designer, the contractor and the asset owners use to keep movement within its limits.

Industry

Infrastructure

Measurements

5

Sources cited

4

1. Infrastructure · Excavations and tunnelling

   The ground moves, and so do the neighbours

   Digging a deep basement or driving a tunnel under a city moves the ground, and with it the buildings, pipes and railways above. The design predicts how much; the observational method checks it as the work advances. Readings that arrive in minutes, not days, let the team change the work before a neighbour is harmed.

2. What is measured

   Settlement, deflection, water and vibration

   Automatic total stations read prisms on façades for settlement and movement, in-place inclinometers follow walls and ground, piezometers watch the water around the works, and GNSS stations hold the reference outside the zone. Geophones on sensitive buildings record vibration from piling and tunnelling.

   Instruments

   Automatic total stations · Inclinometers · Piezometers · GNSS · Geophones

3. The base node

   Every point against its prediction

   The zone’s node computes movement from each total station cycle and GNSS solution, compares every point with its predicted value and its amber and red triggers, and alerts the designer, the contractor and the asset owner the moment a trigger is reached, signing every value.

4. Radio and links

   LoRaWAN from the boreholes

   Piezometers and inclinometers in boreholes reach a gateway over LoRaWAN at very low power, with no cables across a busy site. Total stations, GNSS and the gateway reach the project over cellular, and long tunnel drives use the tunnel’s own fibre underground.

   Links

   LoRaWAN · Public cellular · Fibre

5. How it works

   From a moving façade to a changed sequence

   As the excavation deepens, a total station sees a façade prism settle toward its amber trigger. The node compares it with the prediction and alerts the designer, who changes the excavation sequence and adds props. Settlement slows, and the record keeps every reading and decision.

6. From order to operation · Order

   Scope the works and the neighbours

   The scope reads the design’s predicted movements and trigger levels, the zone of influence, the buildings, railways and utilities within it, and their owners’ limits. Nexus Observatory Inc. returns the instrument plan, the communications design, the reporting to each asset owner and a price per point and per month.

   Plan a deployment

7. From order to operation · Survey

   Condition survey before work

   Crews survey every building in the zone with the designer: condition, cracks, foundations and where prisms and geophones can be fixed. They choose stable buildings for total stations with lines of sight, borehole positions, and GNSS reference sites outside the zone, and record coverage and power.

8. From order to operation · Permits

   Owners, access and limits

   Each building, railway and utility owner agrees access, fixings and the limits on its asset, often through formal agreements. The monitoring plan, triggers and actions are agreed with the designer and the client, and every agreement is kept with the zone’s record.

9. From order to operation · Build

   Build to the monitoring plan

   Total stations, GNSS receivers, piezometers, inclinometers, geophones, endpoints and nodes are built, tested together and enrolled with their identities. Each point is configured with its predicted movement and triggers from the design, and labelled with its point code. Configurations are checked on the bench first.

   Open the Station Builder

10. From order to operation · Install

    Install and baseline before excavation

    Crews fix prisms and geophones, drill and install piezometers and inclinometers, mount total stations on stable buildings and set GNSS references outside the zone. Every point is surveyed in, and a baseline period completes before the first excavation or the first ring.

11. From order to operation · Commission

    Prove the baseline

    Each node proves its identity. Total station cycles are checked for closure, GNSS for stability, piezometers against manual dips and inclinometers against a manual probe survey. Amber and red alerts are tested to the designer, the contractor and each asset owner.

12. From order to operation · Operate

    Build by the observational method

    Designers compare every point with its prediction as the work advances. Amber triggers bring review and changes to the work, red triggers stop it until the cause is understood. Asset owners see movements on their assets, and every decision is kept with its readings.

13. From order to operation · Maintain

    Keep lines of sight and boreholes

    Prisms are cleaned and replaced when blocked, total stations checked against references, borehole sensors read manually on schedule, and points re-established when works destroy them. Monitoring continues until movements stabilise, and every change is recorded. Spares are kept on site, so a lost point is restored within the shift.

    Book field services

14. Data products

    For designers, contractors and owners

    Designers and contractors receive movement against prediction and triggers; designers, contractors and asset owners receive amber and red alerts; building, railway and utility owners receive their assets’ movement reports; clients and insurers receive close-out records. Each product carries its survey and calibration.

    See the data products

15. Evidence

    The observational method, on record

    Every reading, trigger, review and change is signed and kept. Instrumentation follows the geotechnical monitoring standard, design follows the observational method of the geotechnical code, vibration follows the building vibration standard, and records join the project information, so owners and insurers can check them.

    Drawn against

    ISO 18674 · EN 1997 · DIN 4150-3 · ISO 19650

16. What you get

    Structural and ground-movement monitoring

    GNSS, InSAR, tilt, strain and fibre sensing on bridges, dams, slopes, tailings and pipelines, with alert thresholds set by the owner. Delivered as managed service and data licence, for infrastructure, mining and pipeline operators, transport agencies. Scale: Asset portfolios. Service levels are written as numbers you can measure on your own dashboard.

    Talk to sales

17. Next step

    Plan excavations and tunnelling with us

    Tell us the site, the measurements and the rules it answers to. We reply with a survey proposal, a design and a scope for excavations and tunnelling. An engineer replies with a survey proposal and a scope, and the plan grows from one site to the network you need, at your pace.

    Plan a deploymentOpen the Station BuilderOpen the Studio

01The place and its hazards

Where it runs, and what can go wrong.

Operating contextDeep basements, shafts and tunnels are designed with predicted ground movements and trigger levels, and built under the observational method: monitor, compare with prediction, and act when triggers are reached. Owners of nearby buildings, railways and utilities set their own limits, and monitoring follows geotechnical instrumentation standards.

Hazards

• Settlement damaging nearby buildings and utilities
• Excessive wall deflection in deep excavations
• Water inflow and loss of ground
• Vibration from piling and tunnelling
• Readings that arrive too late to change the work

02What must be measured

What, where, how often, and under which rules.

Each measurement names where it is taken, how often, and the public standard or regulation behind it. Numbers in the sources column open the cited source below.

03The observation stack

From one base unit to a network.

The same blocks at every scale: instruments and a base node, a site with its radio, a fleet run as one, and a network federated on the open protocol.

1. 01

   Base unit

   A monitoring point: a piezometer or inclinometer on a LoRaWAN endpoint, or a total station and GNSS on an edge node.

   Build a station →
2. 02

   Site

   A works zone: points around the excavation or along the drive, total stations on stable buildings and cellular to the project.

   Plan a site →
3. 03

   Fleet

   Every works zone of a project run as one fleet, with one trigger process and one record.

   Managed offers →
4. 04

   Network

   Designers, contractors and asset owners share movement data through open standards.

   The open protocol →

• 01GNSS geodetic station
• 02Water level gauge
• 03Vibration and condition monitor
• 04LPWAN endpoint
• 05LoRaWAN gateway
• 06Edge node (Wedge)
• 07Cellular modem/router
• 08Battery case

Radio and links

LoRaWAN

Piezometers and inclinometers in boreholes around the works reach a gateway at very low power, without cables across the site.

Radio and links

Public cellular

Total stations, GNSS and the gateway reach the project over cellular.

Radio and links

Fibre

Long tunnel drives use the tunnel’s own fibre for points underground.

Edge computeThe zone’s node computes movement from each total station cycle and GNSS, compares every point with its predicted value and trigger levels, and alerts the designer and contractor at once when an amber or red trigger is reached.

PowerTotal stations and nodes run on site or building power with batteries; borehole sensors on batteries for the life of the works.

04How it works

From the instrument to the product.

One observation’s path, tier by tier, with the interface on every link and a bill of materials below; then how the one node grows to a site, a fleet and federated networks.

05From order to operation

Every step, from the first call to a running site.

The same crew and the same record carry the work from scope to maintenance.

1. 01 Order

   Scope the works and the neighbours

   The scope reads the design’s predicted movements and trigger levels, the zone of influence, the buildings, railways and utilities within it, and their owners’ limits. Nexus Observatory Inc. returns the instrument plan, the communications design, the reporting to each asset owner and a price per point and per month. 2

2. 02 Survey

   Condition survey before work

   Crews survey every building in the zone with the designer: condition, cracks, foundations and where prisms and geophones can be fixed. They choose stable buildings for total stations with lines of sight, borehole positions, and GNSS reference sites outside the zone, and record coverage and power.

3. 03 Permits

   Owners, access and limits

   Each building, railway and utility owner agrees access, fixings and the limits on its asset, often through formal agreements. The monitoring plan, triggers and actions are agreed with the designer and the client, and every agreement is kept with the zone’s record.

4. 04 Build

   Build to the monitoring plan

   Total stations, GNSS receivers, piezometers, inclinometers, geophones, endpoints and nodes are built, tested together and enrolled with their identities. Each point is configured with its predicted movement and triggers from the design, and labelled with its point code. Configurations are checked on the bench first.

5. 05 Install

   Install and baseline before excavation

   Crews fix prisms and geophones, drill and install piezometers and inclinometers, mount total stations on stable buildings and set GNSS references outside the zone. Every point is surveyed in, and a baseline period completes before the first excavation or the first ring. 1

6. 06 Commission

   Prove the baseline

   Each node proves its identity. Total station cycles are checked for closure, GNSS for stability, piezometers against manual dips and inclinometers against a manual probe survey. Amber and red alerts are tested to the designer, the contractor and each asset owner.

7. 07 Operate

   Build by the observational method

   Designers compare every point with its prediction as the work advances. Amber triggers bring review and changes to the work, red triggers stop it until the cause is understood. Asset owners see movements on their assets, and every decision is kept with its readings. 23

8. 08 Maintain

   Keep lines of sight and boreholes

   Prisms are cleaned and replaced when blocked, total stations checked against references, borehole sensors read manually on schedule, and points re-established when works destroy them. Monitoring continues until movements stabilise, and every change is recorded. Spares are kept on site, so a lost point is restored within the shift.

06Data products and integration

What it delivers, to whom, and into which systems.

Data products

• Movement against prediction and triggersDesigners and contractors
• Amber and red alertsDesigners, contractors and asset owners
• Asset movement reportsBuilding, railway and utility owners
• Close-out recordsClients and insurers

Integration

• Project information modelPoints and readings are linked to the model under ISO 19650 practice.
• Asset owners’ systemsEach owner receives its assets’ movements in the format agreed.
• Design checksReadings are exported for back-analysis against the design predictions.

Exchanged through ISO 18674, OGC SensorThings API, ISO 19650.

07Questions buyers ask

Before you scope it.

Who sets the triggers?

The designer, from the predicted movements and each asset owner’s limits.

What happens at a red trigger?

The work stops at that location until the cause is understood, as the plan says.

Can a railway owner see its track?

Yes. Each owner receives its assets’ movements as agreed.

When does monitoring end?

When movements have stabilised and the designer and owners agree.

08Resources

The sources behind this page.

Public standards, regulations and guidance, cited where they apply. Each applies only where its jurisdiction or scope does.

1. 1ISO 18674: Geotechnical investigation and testing, geotechnical monitoring by field instrumentationInternational Organization for Standardization
2. 2EN 1997 (Eurocode 7): Geotechnical design, including the observational methodEuropean Committee for Standardization
3. 3DIN 4150-3: Vibrations in buildings, effects on structuresDeutsches Institut für Normung
4. 4ISO 4866: Mechanical vibration and shock, vibration of fixed structures, guidelines for measurementInternational Organization for Standardization

09Related

Use cases and solutions.

10Infrastructure: specialized fields

Other fields of this industry.

Bring us the site.

Plan a deployment, configure a station, model it in the Studio or talk to sales. The form names who receives your details.