Building Model Check
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.
Check Slabs with Small Area and Aspect Ratio:
This warning will be prompted if a very small slab exists in the model. However this warning can be ignored if it is the model intention.
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 effetively 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 boudary of the supporting beams.
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.
Check Overlapping Slabs with Beams/Walls:
This checks for beams/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 are connected correctly to the beam instead of overlapping it.
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.
This warning can be ignored for flat slab systems. Hence, just 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.
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.
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.
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 parellel axes that are say 50mm part - there is negligable difference in structural behaviour.
- Keep axis short and localised 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 Inserion"
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.
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.
To rectify this warning, you may click on the “Review” tab and click on “Fix the Almost Orthogonal axis”.
Note : This warning may lead to problems with meshing of slabs in FE Floor Analysis or Building Analysis. It is not a serious nor critical error.
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.
Check Elevation Overlapping of Columns and Walls:
This error is prompted when a slanting/sloping column coincides with a straight column in elevation.
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 analysed 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).
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 embeded inside a column and wall.
Delete such beams if it unintentional, else the program will convert it to a "rigid member" in the analysis.
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"
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