Shapes Supported in Conduit Feature Definitions

The following conduit shapes are supported. Each shape is parameterized by one or more characteristic dimensions as shown in the reference figure.

The allowable conduit shapes include:

Arch

The cross sectional shape of an Arch link is loosely defined by its Span and Rise. The remaining attributes are derived based upon internal look-up tables.

Basket Handle

The required input to define the size of a Basket-Handle Arch is simply its Rise (H). Unique to basket-Handle shape is the ratio of the bottom width (W) of the Arch to be .99135 of the Height (H). The remaining shape characteristics are derived based upon internal look up tables.

Box

The required input to define the size of a Box are its Span(W) and Rise (H).

Catenary

The only user input to define a Catenary Arch is its Rise (H). The shape is principally defined with the cosine function, where the coefficients a and b are determined by computation.

Circular Channel

A circular pipe or channel is simply defined by its Diameter (D).

Egg

The only user input to define an Egg Shaped Arch is its Rise (H). The remaining attributes are derived based upon internal tables. Its unique cross sectional characteristics are based upon a top radius equal to one-third of its height. The definition of the bottom portion of the arch is more complex and based upon internal angles.

Ellipse

An Elliptical shaped pipe is defined by its Rise(H and Span(W). The elliptical coefficients of A and B respectively correspond to H/2 and W/2.

Gothic

A Gothic Arch is well defined based upon its Height or Rise (H). At its greatest width (W) the unique proportion of W to H is 1.115. Also unique to this arch type is the existence of the equilateral triangle with side lengths of W.

Horseshoe

The required input to define the size of a Horseshoe Arch is simply its Height or Rise (H). The remaining attributes are derived based upon internal tables. Sometimes referred to as "Boston Horseshoe Arch", the unique cross sectional characteristics are based upon a top radius equal to half of its height. The definition of the bottom half of the arch is more complex and based upon internal angles.

Irregular Closed Conduit and Irregular Channel

The irregular shapes allow user-defined shapes by defining a table of offset/elevation pairs.

Modified Basket Handle

The Modified Basket Handle Arch is only defined by its Rise(H) and its Span (W). The top portion is a semi-circular in shape with a radius equal in size to half its Width (W).

Parabolic Channel

A channel defined with a general form parabolic function is defined by its Rise(H) and Span(W).

Power Channel

A channel defined with the power function is defined by its Rise, Span and the exponent (n) to the following general form equation: y = xn

Rectangular Channel

The required input to define the size of rectangular channel are its Span(W) and Rise (H).

Rectangular-Round

A Rectangular-Rounded shape is completely defined by three attributes:

H = Height or Rise

W = Width or Span

D = Radius of the rounded portion of the channel

Rectangular-Triangular

A Rectangular-Triangular shape is completely defined by three attributes:

H1 = Rise of the entire section

H2 = Triangle Height (triangular shaped section of the channel )

W = Span Width of the entire section

Semi-Circle

A Semi-Circular Arch is sized only by its Rise or Height (H). The semi-circular shape has a radius (R) equal to its Height (H). At its largest, at its base, its width is twice the Height (H).

Semi-Ellipse

The required input to define the size of a Semi-Elliptical Arch is simply its Height or Rise (H). Unique to this arch shape is that characteristic that at its widest dimension, at its base, the width is equal to its height (H). The shape is geometrically defined with the function of an ellipsis, where the traditional elliptical coefficients of A and B respectively correspond to H/2 and H.

Trapezoidal Channel

A trapezoidal channel is defined by its Rise(H) and its bottom width (W) and the left (SL)and right (SR) side slopes.

Triangular Channel

A triangular shaped channel is defined by its Rise(H) and its Span (W).

Irregular Closed Section and Irregular Channel

These shapes allow user-defined conduit cross-section shapes of virtually any shape. Instead of inputting diameter, rise or span, the irregular shapes are defined by an Elevation / Width table