Building walls

The "Building walls" module was developed for designing the following:

• Reinforced concrete walls with earth pressure with or without footings (basement walls) or on beam foundations.
• Reinforced concrete load-bearing walls without lateral pressures with or without footing (load-bearing walls) or supported at the start by a beam or slab (shear walls).
• Masonry walls (brick or concrete block) with or without foundations (floating external fixity beams or masonry walls starting at foundations).

Design premises for building walls

• They do not need to keep their shape over the entire height, instead, each span or side is independent.
• They may cross other supports such as columns, and columns supported by walls, or a wall supported by several columns, are permitted on any floor.
• They can contain earth with a water table at a certain elevation by applying horizontal earth pressures at rest on one or both sides.
• The material is not only reinforced concrete. It can be of generic masonry, in which we define its characteristics, or of concrete block. If the material is concrete block, the selected standard will be applied. Optionally, a reinforcement with horizontal tendon reinforcement and vertical reinforcement can be used, if it needs to be checked as reinforced masonry.
• Allows users to define openings in their faces, such as doors or windows.
• The foundation of the wall can be defined as a floating beam or continuous footing without external fixity.

Discretisation carried out on building walls

Just as with shear walls, the discretisation model is by triangular thick-sheet finite elements with six nodes (three vertices plus three midpoints of the sides) and with six degrees of freedom per node. In contrast to the shear walls, the meshing in the walls is decided by the program itself and is composed of irregular triangles of variable dimensions that refine their mesh to adapt to the nodes of their edges and the irregularities of the geometry. For example, the program matches the nodes of the bars in the floor slabs with the nodes of the triangles in the mesh. This is reason enough for the results obtained by the program to be different if a wall or a screen is placed on the same structure, although they will be similar.

Since there is a rigid diaphragm in the floor slabs, it is clear that at floor level the degrees of freedom are restricted, as is also the case with the shear walls. However, it is important to highlight this here, since if a wall is supported on two columns (which cannot be done with shear walls), the supporting beam at floor level will be designed for bending, but will not be designed for axial forces such as a lower tensile tie rod, which can occur when we enter walls that work as a beam-wall or deep beams.

CYPECAD reinforcement criteria and CYPECAD checks on building walls

In both walls and shear walls, it is important to remember that a thick sheet with uniform reinforcement on both sides is being reinforced and reinforcement cannot be arbitrarily concentrated, either at the ends or at the corners where it meets other sides. This can lead to an increase in the ratio compared to other manual solutions where the vertical reinforcement is concentrated at those points or edge areas where they are most likely to be needed.

For walls, this situation can be improved in some cases by placing columns at corners and ends, the sides of which have dimensions equal to the thickness of the wall sides. This is not possible with shear walls. In such cases, firstly, the program gives the reinforcement of the wall sides with their elevations, and secondly, the reinforcement of the columns in the column table. It is therefore advisable to manually complete the wall drawings using section details per floor including the reinforcement of the columns embedded in the wall to provide a joint reinforcement.

The section design is the same as that for the shear walls. The only difference is that they are consulted via the "Edit walls" option in the "Beams/Walls" menu, in the "Results" tab.

Results output

• Diagrams of normal and shear stresses can be checked for the full height of the shear wall for each calculated combination, as well as displacement diagrams for the defined loadcases.
• The diagrams are shown in colour and scaled according to proportional values, with minimum and maximum values shown.
• The reinforcement can be checked and modified at the designer's discretion, as can the thicknesses, which are shown in red when they are not compliant. The compliance factor in % of the reinforcement in place and the areas to be reinforced, if any, can also be checked.
• The program can list the worst case forces in the span and the forces by loadcase of the resultant.
• For basement walls, the "Basement walls" drawing can be obtained, which shows the elevation of each wall span, with the reinforcement table for each span per storey, including the approximate measurement.

User license

For CYPECAD to be able to analyse and design walls, the user license must include the "Building walls" module in addition to CYPECAD.

Other features

To access other features offered by the program, several modules can be found on the "CYPECAD modules" page.