The building model check will check for possible modelling errors or mistakes.
- It is highly recommended to perform "Building Model Check" progressively when building the model so that problems are identified early in the project before running an analysis.
- Not all problems listed are errors. Some of them might be warnings which requires you to verify and decide whether to rectify or to ignore
- Actual member labels will be stated; hence go back to locate and verify the problem stated
The list of errors/warnings in the building model checks are:
Overlapping Slabs Check
This error occurs when two slab edges overlap each other. The slab nodes should not be overlapping each other, otherwise slab loads may not be calculated correctly.
This is a critical error and must be corrected.
Check Slabs with Small Area and Aspect Ratio
This warning will be prompted if a very small slab exists in the model.
This is not a critical error but a warning, which can be ignored if it is the model intention after due checking.
Check Invalid Slab polygon
This error occurs when the slab edges are not inserted properly and therefore the slab edge nodes are not entirely connected effectively to the beam nodes. This may result in missing slab loads on the beams.
To investigate this error you should check in plan view if the slab nodes are effectively supported by the beams. Also check if the shading of the slab is entirely within the boundary of the supporting beams.
This is a critical error and must be corrected.
Overlapping Columns Check
This is to check if two or more columns exists in the same location. If this error occurs, search for the overlapping columns using the “structure tree” and delete one of the two overlapping columns.
This is a serious error and should be corrected. Check Overlapping Slabs with Beams/Walls
This checks for beams or shear walls that might be overlapping with existing slabs.
If this error occurs, delete the existing slab and re-model it to ensure that the slabs edges are connected correctly to the beam or shear wall instead of overlapping it.
This is a serious error and should be corrected. Check Overlapping Slabs with Columns
This warning is to check on whether columns are modelled within the slab panels; columns should always be at the edge of the slabs for beam slab system.
This warning can be ignored for flat slab systems. Hence, to by pass this check, untick "Column Inside Slab Panels Check" if the model is a flat slab.
Another workaround to avoid this warning in a flat slab model is to insert columns on the slab boundaries as shown in the example below.
This is critical error for beam and slab layout, which must be rectified. It can be ignored for flat slab system.
Check Overlapping Beams with Beams and Walls
This error occurs when there are two or more beams/walls overlapping each other.
To ensure that the beams/wall do not overlap, click "Yes" when prompted with the message to split the beams when crossing over supporting spans.
This is a serious error and should be corrected. Validity of Axis Intersections Check
This error occurs when an axis is modified and no longer intersects with the corresponding axis but the intersection is still needed by an existing member.
This is a serious error and should be corrected.
Proximity of Axis Intersections Check
When the intersection of axes are too close to each other (less then 10mm) this warning will be prompted.
Having too many intersection of axes too close to each other may promote mistakes in modelling and it is very difficult to snap to the correct intersection point.
In the example below, the 3 axes seem to be intersecting each other at a common point, but when zoomed in, there are actually 3 no. of axes intersection that are very close to each other.
This check is more of a warning than an error. The following are good axes modelling guidelines to prevent this problem :
- When creating additional axis (example Axis G above), ensure to snap exactly at the correct intersecting point instead of a visual estimation
- Do not model axes too close to each other. Take note that good structural behavior is to be prioritized; minor architectural offsets should be ignored. For example, it is not advisable to model 2 no of parallel axes that are say 50mm part - there is negligible difference in structural behavior.
- Keep axis short and localized to where is used by members. In other words, it's not always necessary to draw very long axis if it is only used by a single column as a long axis will intersect with many other axes to create unused (redundant) nodes.
- If axes and members are already created, there is a function to automatically shorten the axes by selecting axes > Right-click > "Stretch Axis to Member Insertion"
Check Overlapping Axes
This is to check if two or more axes exists in the same location (example shown below).
To fix this, delete one of the overlapping axis.
If members are already created using a particular axis, it will be necessary to delete the member first. To find out members associated with the axis :
1. Select the axis
2. Right- click > Pick "List Members using the Axis"
This is not a critical error; analysis & design can still be done. However, there is be confusion which axis will be used for associated elements in the design and drawing production phase.
Axis Exact Orthogonality Check
This warning is prompted as a check on the orthogonality of the axes if a nearly orthogonal axis exists, example if the axes has a rotation angle of 0.001 degrees.
It is not critical error and is mor of warning; may be ignored based on user's judgement.
This warning may lead to problems of slab insertion or meshing of slabs in FE Floor Analysis or Building Analysis.
This problem may be caused by imported axes from Dxf drawing, where the axes drawn may inherently have small angles.
Check Overlapping Long Columns and Walls at Lower Storeys
This error occurs when the column length of the upper storey overlaps with the columns below.
To solve this error, ensure the column “len” value in the column properties is entered appropriately :
- For example if a particular column modelled in ST02 has a "len" = 2, it will span downwards 2 storeys.
- It is not necessary to model any column in ST01, otherwise it will overlap with the column above.
This is a serious error and should be rectified.
Check Elevation Overlapping of Columns and Walls
This error is prompted when a slanting/sloping column coincides with a straight column in elevation.
This is a serious error and should be rectified.
Check Zero Length Columns and Walls
This error occurs when the beam depth exceeds the storey height in the model. This will result in the effective length of the column/wall member to be zero and analyzed as a rigid member.
To solve this, ensure that the storey height is more than the depth of the beam (or the highest depth of the beam in the storey).
This is a serious error and should be rectified.
Check Zero Clear Length Beams
This is to check if any of the effective length of the beams are zero, i.e. the length is entirely embedded inside a column and wall.
Delete such beams if it unintentional, else there will be erroneous analysis and design.
This is a serious error and should be rectified.
Check Repeating Labels
This error will occur when members in the model have similar repeated labels.
To solve this, search for the repeated labels using the “structure tree”, click on the properties of the members and rename the member label.
Alternatively, to rename members of entire floor or model, go to "Review" tab > Re-label Members.
This is a serious error and should be rectified.