User:Kovposch/Proposed features/More bridge structural details

More bridge structural details
Proposal status:	Draft (under way)
Proposed by:	Kovposch
Draft started:	2022-08-24

Proposal

Differentiate different sub-types of bridge structures, and highlight more bridge elements.

Rationale

Disclaimer: Not an engineer

Bridge structures

• Overlap between bridge=cantilever, bridge:structure=arch, and bridge:structure=truss can be difficult to determine in some cases (criteria is the mechanism of support)
• Some common attributes exists that can be characterized
• Much distinct looks between variations compared to other types
• Balanced cantilever viaduct has conflict between bridge=cantilever and bridge=viaduct
• There are some dubious naming viz Nielsen-Lohse bridge (commonly found, and standard terminology in Japan), which the credited authors didn't actually construct such a bridge even if it might have been patented similarly

Bridge elements

Expansion joint

Expansion joints connect the series of spans to form the whole bridge.

• Assist in outlining bridge=* and man_made=bridge (whether to include ramp or abutment in its extent, or how to defining limit jointless / integral abutment bridge is out-scope)
• Helpful to align and trace other objects
• Is a source of noise & vibration; and a point of failure for maintenance, repairs, and disaster management

Parapet

Parapets form the sides of a bridge deck, as well the edge of any raised structure. This can be extended to roof, terrace, balcony, and elevated walkways.

• Assist in outlining man_made=bridge
• Often coincides with the bridge outline

Tagging

Bridge structures

General

• bridge:span=* (There exists bridge:spans=* to count the number of spans. That's difficult to define and choose from main span, thus out-scope): If different span types exists, currently propose to tag on *way=* + bridge=* for the time being, due to uncertainties with a potential bridge:part=* viz the abandoned Bridge3D from a decade ago. In particular, bridge:part=ramp can't seem to handle viaducts, flat raised approach, and intermediate gradients.
  • bridge:span=simple
  • bridge:span=continuous
  • bridge:span=cantilever
  • bridge:span=balanced_cantilever
  • bridge:span=suspended (Don't confuse with bridge:structure=suspension)

• bridge:deck=*
  • bridge:deck=through
  • bridge:deck=half-through (aka "pony")
  • bridge:deck=deck

• bridge:hanger=*
  • bridge:hanger=vertical
  • bridge:hanger=inclined (aka Nielsen)
  • bridge:hanger=network
    • bridge:hanger=cross (aka Nielsen-Lohse in Japan)
    • bridge:hanger=radial (aka "spoked wheel")

TBD: Truss, bowstring arch

Arch bridge

• bridge:structure:arch=*
  • bridge:structure:arch=through
  • bridge:structure:arch=tied
• bridge:structure:arch:form=*
  • bridge:structure:arch:form=single
  • bridge:structure:arch:form=twin
• bridge:structure:arch:rib=*
  • bridge:structure:arch:rib=solid
  • bridge:structure:arch:rib=braced
    • bridge:structure:arch:rib=spandrel
• bridge:structure:arch:spandrel=*
  • bridge:structure:arch:spandrel=open
  • bridge:structure:arch:spandrel=closed
• bridge:structure:arch:shape=*
  • bridge:structure:arch:shape=elliptical
  • bridge:structure:arch:shape=segmental
  • bridge:structure:arch:shape=semi-circular
• bridge:structure:arch:profile=*
  • bridge:structure:arch:profile=basket_handle

TBD: Asymmetric arch

Bridge elements

Arch

• bridge:support=arch: Useful when the arch isn't vertical. 3D geometry can be derived together with height=*, or tilt=*.

Expansion joints

• man_made=expansion_joint (man_made=* to allow for use on other features)
• expansion_joint=*
  • expansion_joint=finger
  • expansion_joint=compression
  • expansion_joint=gland
  • expansion_joint=modular ?

Parapets

• barrier=* + parapet=yes

Rendering

Might be possible to draw up icons for man_made=bridge in 2D renders to function as a landmark.

3D renders may attempt to generate lookalikes from archetypes.

Features/Pages affected

• man_made=bridge
• bridge=*
• bridge:structure=*
• bridge:support=*

Comments

Please comment on the discussion page.