stairwell

sectionproperties.pre.library.concrete_sections.stairwell(d: float, b: float, t1: float, t2: float, a: float, dia_bar: float, area_bar: float, spacing: float, cover: float, double: bool = True, n_circle: int = 4, conc_mat: Material = Material(name='default', elastic_modulus=1, poissons_ratio=0, yield_strength=1, density=1, color='w'), steel_mat: Material = Material(name='default', elastic_modulus=1, poissons_ratio=0, yield_strength=1, density=1, color='w')) → CompoundGeometry[source]

Constructs a reinforced concrete stairwell section.

Constructs a reinforced concrete stairwell section of depth d, width b, top/bottom thickness t1, left/right thickness t2 and door opening width a. The wall reinforcement has a maximum spacing of spacing and is doubly reinforced if double is set to True, or singly reinforced if it is set to False.

Note

As the reinforcing bars are described by discretised circles, the area of each bar is required to ensure that the correct reinforcing area is provided.

Parameters:

  • d (float) – Concrete wall depth

  • b (float) – Concrete wall width

  • t1 (float) – Top/bottom concrete wall thickness

  • t2 (float) – Left/right concrete wall thickness

  • a (float) – Door opening width

  • dia_bar (float) – Diameter of the reinforcing bars, used for calculating bar placement

  • area_bar (float) – Area of the reinforcing bars

  • spacing (float) – Maximum spacing of the reinforcement bars, the calculated spacing is equal to ceil(extent / spacing) + 1

  • cover (float) – Clear cover to the reinforcing bars

  • double (bool) – If set to True, provides two layers of reinforcement to the wall. If set to False, provides a single central layer of reinforcement to the wall. Defaults to True.

  • n_circle (int) – Number of points used to discretise the circular reinforcing bars. Defaults to 4.

  • conc_mat (Material) – Material object to assign to the concrete area. Defaults to pre.DEFAULT_MATERIAL.

  • steel_mat (Material) – Material object to assign to the steel area. Defaults to pre.DEFAULT_MATERIAL.

Raises:

ValueError – Geometry generation failed

Returns:

Reinforced concrete stairwell section geometry

Return type:

CompoundGeometry

Example

The following example creates a 5000 mm deep x 2500 mm wide concrete stairwell section, with top/bottom walls 180 mm thick, left/right walls 200 mm thick and a door opening of 900 mm. The wall is reinforced with a double layer of N16-200 with 30 mm cover. A coarse finite element mesh is generated to show the different material regions:

from sectionproperties.pre import Material
from sectionproperties.pre.library import stairwell
from sectionproperties.analysis import Section

concrete = Material(
    name="Concrete",
    elastic_modulus=30.1e3,
    poissons_ratio=0.2,
    yield_strength=32,
    density=2.4e-6,
    color="lightgrey",
)
steel = Material(
    name="Steel",
    elastic_modulus=200e3,
    poissons_ratio=0.3,
    yield_strength=500,
    density=7.85e-6,
    color="grey",
)

geom = stairwell(
    d=5000,
    b=2500,
    t1=180,
    t2=200,
    a=900,
    dia_bar=16,
    area_bar=200,
    spacing=200,
    cover=20,
    double=True,
    n_circle=12,
    conc_mat=concrete,
    steel_mat=steel,
)

geom.create_mesh(mesh_sizes=[0])  # a size of zero creates a coarse mesh
Section(geometry=geom).plot_mesh()

(Source code, png, hires.png, pdf)

../_images/sectionproperties-pre-library-concrete_sections-stairwell-1.png

Reinforced concrete stairwell section geometry