../../_images/section-opening.png Create Opening




Defines openings of a cross section.


Cross Section Editor

../../_images/section-opening_m.png Modify Opening




Modifies the openings of a cross section


Cross Section Editor

Defines openings of a cross section.

Openings are plane areas, which are described via a polygon, inside an outer boundary.

For creation of an opening, the following options are available:

Pick Lines or Curves

Creates an element by enclosing an area with the selected objects. Valid selection choices include closed polylines and lines.


Creates an rectangular element by selecting two diagonally opposite points.

Point in Area

Creates an element by selecting a point within a region that is enclosed by objects. Valid selection points are within an area with surrounded by closed polylines and lines.


By pressing the enter key when the last polygonal point is entered, the element will automatically be closed by connecting to the first point. This option is only available after a minimum of three points have been selected.

General Tab

Information regarding the assignment of construction stages refer to the chapter Construction Stages of Cross Section Parts.

A detailed description of these properties can be found in the chapter ‘POLY - Polygonal Cross-Section Element/Blockout’ of the manual AQUA.

Points Tab

This tab is only available after analysis when modifying an existing boundary of a cross section, and not during creation.

This menu is based on the defined points/vertices on the boundary. The ‘name’ column lists the names of the defined points/vertices.

The points can be used to define structural line loads with eccentricty for structural line which has a cross section.

The point names can be displayed or hidden with the visualisation dialog.

A detailed description of perimetric reinforcement can be found in the chapter ‘VERT - Polygon Vertices in Absolute Coordinates’ of the manual AQUA.

Perimetric Reinforcement Tab

Reinforcement for the perimeter is defined as longitudinal reinforcement at a defined distance from the boundary. The requirement of perimetric reinforcement is switched on by activating the tickbox at the top left of the tab.

Two possibilities are available for the input the reinforcement values:

  • Definition of the minimum and maximum reinforcement as total reinforcement area, e.g. in [cm²]

  • Definition of the minimum and maximum reinforcement with the grade of reinforcements, e.g. in [cm²/m]

During calculation single reinforcement bars are generated using the input for diameter, distance, reinforcement and maximum reinforcement. With ‘Distribution of bars’ several possibilities are available for the distribution of the single bars.

If a nominal cover is defined for the concrete material at ‘Material’ button ‘Extended’ and an edge property is generated with ‘Assign Edge Properties’, this nominal cover can be considered with a tick at ‘Consideration of the nominal cover of the edge properties’.


The distance of the reinforcement from the edge of the polygon is generated as follows: diameter/2 + distance of the reinforcement from the perimeter + nominal cover (when input at the material and generated as edge property) or only the inset of reinforcement from perimeter, if a nominal cover is not considered at the edge properties.

The perimetric reinforcement is not visible in the Cross Section Editor. Please use the program Result after the calculation of the cross section and saving the data into the database.

A detailed description of perimetric reinforcement can be found in the chapters ‘Reinforcement’ and ‘CURF - Perimetric Reinforcement’ of the manual AQUA.