IoT displacement sensor
4.8 mm
10 Hz · 2026-09-25 09:14:02 HKT
signed · calibrated01 / 09
The governed asset
A bridge is not a mesh. Every element below is a semantic object with a persistent identifier, an IFC class, a location on the alignment, and a chain of evidence attached to it. Select a component.
02 / 09
The handover is where meaning dies
Most asset data is not wrong — it is unreadable. Between authoring tools, between disciplines, between the project and the operator, meaning collapses into names, layers and drawing notes. Switch on the four moves below and watch the same bearing become machine-readable.
AI-readiness index
19
Manual re-entry required — not AI-readable.
Semantic retention34%
Readable attributes11/48
Requirement coverage0%
Provenancenone
Cross-discipline exchange
The same bearing, as a machine sees it
{}
Simulated workshop model. Figures show relative effect, not measured industry benchmarks.
03 / 09
Evidence, and the gates it must pass
Three independent records describe Bearing B-17. Before any AI is allowed to reason about them, four information gates are evaluated. Switch scenarios in the bar above to change the evidence.
Computer-vision inspection
62% conf.
Finding: edge deformation, east bearing seat
signed · model v3.1Annual principal inspection
Condition state 2
Engineer C. Wong · revision P03 · 2025-11-08
approved
Pre-AI information gates
Governed engineering requirement
- Requirement
STR-BRG-221 · R04- Limit
- Operational bearing displacement ≤ 7.0 mm
- On breach
- Immediate engineering review
- Authority
- Chartered Bridge Engineer only
04 / 09
Evidence-grounded reasoning
Not a chat window. A decision contract: every material claim carries a citation you can click, an explicit uncertainty, a required professional authority, and a fingerprint of its exact inputs.
“Assess Bearing B-17 and recommend the next governed action.”
Risk classification
MEDIUM
Finding
Recommendation
Rationale
Stated uncertainty
Citations — click to open the source
computing…DEC-2026-0925-A1Replaying unchanged information returns an identical fingerprint and decision ID.
Permanent AI restrictions
- AI cannot declare the bridge safe or unsafe.
- AI cannot impose traffic controls.
- AI cannot approve expenditure.
- AI cannot close a safety finding.
- AI cannot modify an approved engineering limit.
05 / 09
Bounded agents, human authority
Each agent has a narrow read scope, one writable output, and an explicit prohibition. Trusted evidence can produce only a draft. Nothing moves until a named professional authorises it.
Draft work order
WO-HZB-042-0311
06 / 09
Not a black box. A decision you can replay.
Traceability means we can reconstruct which evidence, rule, model, agent and person produced every material decision — and prove that an untrusted input produced no action at all.
Event trace
{}
Machine records stay in English: they are contracts between systems, not prose.
07 / 09
Intelligence is the top layer, not the foundation
AI may reason and prepare actions only after information passes governance. Read the stack from the bottom up.
L5
Governed intelligenceReasoning adapters · bounded agents · human authorisation
L4
Connected asset knowledgeRelationships · requirements · history · uncertainty
L3
Trust and governanceSchemas · provenance · signatures · validation · permissions
L2
Machine-readable asset informationIFC-aligned objects · evidence · identifiers · APIs
L1
Physical asset and delivery systemsBridge · sensors · inspections · construction · operations
08 / 09
Three questions for the room
Discuss first. Open the answer second.
E1Fact, inference, or decision?
Classify each: the sensor value, the computer-vision defect, the risk level, the inspection action.
The sensor value is an observation. The visual defect is a model inference. The risk level is a governed assessment. The inspection action remains a recommendation until an authorised professional approves it.
E2Should AI convert the unit?
Scenario D reports 7.6 inch where the approved contract requires millimetres. Should the system silently convert it?
No. Conversion does not repair an expired calibration or an unverified signature. Stop, withhold the recommendation, and request validated replacement evidence.
E3Where must autonomy stop?
Which actions may AI prepare, and which require professional authority?
AI may draft notifications, inspections and work orders. An authorised professional must make safety declarations, impose traffic restrictions, approve expenditure, and dispatch work.
09 / 09
Do not add AI to yesterday’s BIM. Design tomorrow’s asset information for humans and AI to trust together.
ModelStructured dataConnected knowledgePredictive intelligenceGoverned action
Sources
Go deeper — every claim has a public standard behind it
This Station simulates a bridge asset for teaching. The governance model it demonstrates is drawn from the open standards and public frameworks below.
Open BIM schema & exchange
- buildingSMART — IFC standardtechnical.buildingsmart.org/standards/ifc
- IFC 4.3 documentation (bridges, roads, rail)ifc43-docs.standards.buildingsmart.org
- Information Delivery Specification (IDS)machine-checkable information requirements
- buildingSMART Data Dictionary (bSDD)resolvable classification & property URIs
- bSDD searchsearch.bsdd.buildingsmart.org
- BIM Collaboration Format (BCF)issue exchange between disciplines
- buildingSMART openBIM validation serviceschema & rule checking
Information management & governance
- ISO 19650-1 — information management using BIMISO catalogue
- UK BIM Framework — ISO 19650 guidanceukbimframework.org
- Centre for Digital Built Britain — Gemini Principles archivepurpose · trust · function
- Digital Twin Consortiumcapabilities periodic table
- FAIR data principlesfindable · accessible · interoperable · reusable
Sensors, provenance & trust
- OGC SensorThings APIIoT observation model
- W3C PROV-O — the provenance ontologywasDerivedFrom · wasAttributedTo
- W3C Verifiable Credentials Data Model 2.0signed, verifiable records
- W3C/OGC SOSA — Sensor, Observation, Sample, Actuatorobservation semantics
- Brick Schemaoperational data semantics
- Project Haystackequipment tagging model
AI assurance & bounded autonomy
- NIST AI Risk Management Frameworkgovern · map · measure · manage
- ISO/IEC 42001 — AI management systemsISO catalogue
- EU Artificial Intelligence Act (Reg. 2024/1689)eur-lex.europa.eu
- Model Context Protocolscoped tool access for agents
Open-source openBIM tooling
- IfcOpenShellIFC parsing & scripting
- That Open Company (IFC.js)web IFC viewers
- Speckleobject-level interoperability
- xeokitlarge-model web visualisation
Regional practice & this Station
- CIC BIM Space — Construction Industry Council, Hong Kongbim.cic.hk
- Development Bureau (HKSAR) — BIM adoptiondevb.gov.hk
- Earth LinC Realm — Airwavesearthlinc.earth/realm
- Earth LinC Stationsearthlinc.earth/Stations
- Local BridgeOS prototype (runs only on the demo machine)http://127.0.0.1:8080/#trace