bridge
Let an agent treat a bridge as infrastructure with a structural type, a load rating, an owner, an inspection regime and restrictions of use.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent treat a bridge as infrastructure with a structural type, a load rating, an owner, an inspection regime and restrictions of use.
A structure that carries a road, railway, path, pipe or animal crossing over an obstacle such as water, a valley or another route, while leaving the space beneath open.
What it is for: Crossing obstacles without blocking what lies beneath.
It can be cross it, subject to weight, height and width limits; inspect it, on a regular cycle; rate it, for load capacity and condition; close, repair or replace it.
Distinguishing features
Leaves the space beneath open, unlike a causeway or embankment
Classified by structural form and by what it carries
Has a load rating and inspection history
Wildlife crossings and pipe bridges are bridges too
What it looks like
A deck supported by piers, arches, cables or trusses spanning a gap; ranges from a timber footbridge to a multi-kilometre cable-stayed crossing.
Physical character
span: 2-2000 m - longest suspension spans approach 2 km
design life: 50-120 years
load rating: varies tonnes or load model - set by national codes
How it is recognised
A deck spanning a gap with supports at its ends and often in between
Structural form visible as arch, beam, truss, suspension or cable-stayed
Signs showing weight, height or width limits
Related models
is part of - bridges are links in networks
is a kind of - inherits structural design and inspection
is inspected by - condition ratings drive restrictions
is confused with - homonyms; this entry is the structure
In practice
Families and kinds
by form: beam, arch, truss, cantilever, suspension, cable-stayed
by use: road, rail, foot, pipe, aqueduct, wildlife crossing
by material: stone, timber, steel, concrete, composite
by movement: fixed, bascule, swing, lift
Identifiers
national bridge inventory number country-specific for example the US National Bridge Inventory structure number
Standards and regulation
Eurocodes EN 1990-1999 and national annexes
AASHTO LRFD bridge design specifications
National bridge inspection standards
Failure modes and hazards
Collapse from overloading, scour, fatigue or corrosion
Strikes by over-height vehicles or ships
Scour of foundations in floods
Deferred maintenance that lowers the load rating
Also called
+256
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.bridge-2
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Structure Form, span and materials.
Structural form determines behaviour, inspection and failure modes.
Structural form
Beam, arch, truss or cable.
Structural type
The structural form and spans.
- What is the structural form, and what are its spans? definition
- What materials make up the main elements? definition
Design basis
Code and load model.
Design standard
The code and loads it was designed for.
- To which code and load model was it designed, and when? provenance
- Has it been strengthened since? provenance
Capacity and restrictions What may cross.
Restrictions are what users and routing systems must know.
Load rating
Assessed capacity.
Assessed capacity
The current load rating.
- What is the current load rating? measurement
- When was it last assessed? provenance
Limits of use
Weight, height, width and speed.
Posted limits
The limits posted and enforced.
- Which weight, height or width limits apply? boundary
- How are they enforced? action
Inspection and condition State of the structure.
Inspection is the main defence against failure.
Inspection
Cycle and findings.
Inspection record
Latest inspection and rating.
- When was it last inspected, and what condition rating was given? measurement
- What defects were found? measurement
Foundations and scour
Risk to supports.
Scour assessment
The scour risk and monitoring.
- Is the bridge at risk from scour, and is it monitored? boundary
- What happens in a flood warning? action
Ownership and status Who is responsible.
Ownership decides who inspects, repairs and answers for the bridge.
Owner
Responsible authority.
Owner and operator
The owner and operator.
- Who owns and maintains this bridge? provenance
- How are defects reported? action
Status
Open, restricted, closed, heritage.
Current status
Operational and heritage status.
- Is the bridge open, restricted or closed now? boundary
- Is it a protected heritage structure? definition
What the second pass must settle
- Should named bridges be registered as instances with inventory numbers?
- How should load restrictions be represented for routing agents?
- How should heritage status interact with safety restrictions?