...
Arch
...
bridges
...
A
...
series
...
of
...
tips
...
for
...
modeling
...
arch
...
bridges
...
and
...
soil
...
interaction
...
are
...
listed
...
as
...
follows:
...
- It
...
- may
...
- be
...
- useful
...
- to
...
- create
...
- and
...
- study
...
- a
...
- simplified
...
- model
...
- to
...
- gain
...
- insight
...
- into
...
- structural
...
- behavior.
...
- Creating
...
- a
...
- 2D
...
- model
...
- composed
...
- of
...
...
- objects
...
- may
...
- then
...
- serve
...
- as
...
- a
...
- useful
...
- preliminary
...
- to
...
- the
...
- 3D
...
- model.
...
- A
...
- 2D
...
- model
...
- would
...
- represent
...
- a
...
- longitudinal
...
- section
...
- cut
...
- through
...
- the
...
- bridge
...
- and
...
- soil
...
- mass.
...
- This
...
- approach
...
- would
...
- reduce
...
- the
...
- model
...
- size
...
- and
...
- analysis
...
- time
...
- while
...
- providing
...
- the
...
- benefit
...
- of
...
- useful
...
- information
...
- and
...
- a
...
- comparison
...
- study.
...
- To
...
- most
...
- effectively
...
- model
...
- and
...
...
- the
...
- 3D
...
- bridge
...
- structure,
...
- it
...
- may
...
- be
...
- best
...
- to
...
- use
...
- shell
...
- objects
...
- to
...
- draw
...
- the
...
- arch
...
- segments
...
- in
...
- the
...
- 2D
...
- elevation
...
- view,
...
- then
...
- extrude
...
- the
...
- shells
...
- into
...
- 3D
...
...
- using
...
- Edit
...
- >
...
- Extrude
...
- >
...
- Extrude
...
- Areas
...
- to
...
- Solids.
...
- To
...
- prevent
...
- tension
...
- from
...
- developing
...
- in
...
- the
...
- arch
...
- and
...
- along
...
- the
...
- soil-structure
...
- interface,
...
- gap
...
- (compression-only)
...
...
- objects
...
- may
...
- be
...
- used
...
- to
...
- model
...
- support
...
- points.
...
...
- objects
...
- may
...
- be
...
- useful
...
- for
...
- 2D
...
- bridge
...
- models
...
- in
...
- which
...
- the
...
- arch
...
- or
...
- soil
...
- cannot
...
- carry
...
- tension.
Arch system in 2D
To model an arch system in 2D, shell objects should be used for plane stress problems, and frame objects should be used for frame-type behavior. When using frame objects, a series of linear segments should be modeled to approximate the curvilinear profile of the arch.