What are Clash Detection and Code Checking and how do they function in the data validation processes? What processes and what type of analysis do they carry out within the BIM methodology?
“BIM Clash Detection” is the research of possible interferences among the model objects.
It’s useful to highlight how this type of control has to be carried out both on the model relative to the single discipline and on the integrated model, the so called Merged Model.
A verification of objects interference can offer a series of instances especially in case it is performed on integrated models. Severity of interference and tolerance are the two main criteria making “Clash Detection” a really useful practice.
For example, it is evident how the air conditioning system ducting and cladding will show a different relevance if compared to the interference between the ducting and a structural members (like a beam or a column). Therefore, the fact of having a hierarchy based on different types of interferences available will make the verification itself more efficient.
Similarly important is the principle of tolerance. Simply verifying the presence of a collision between a window fixture and a column isn’t enough even if these are in adherence. Or the same criterion can be adopted backwards, tolerating contacts between objects or suferficial interferences to reduce the number of inconsistencies. In fact, only the most signficant errors are detected.
“Code Checking” as last step of Model Checking
The virtual model of a building is known to be a model made up of parametric objects, or rather of information related objects representing real entities where a certain number of parameters “describes” their features.
Similarly, “describing” regulatory indications, clients’ requirements or indications derived from good project practices, would favour a comparison of such data with the data introduced in the building’s virtual model.
The creation of a database of cross-checking rules is the first step to Code Checking implementation.
Some applications of such procedure are related to geometrics prescriptions (verification of minimal surfaces, volumes, regulatory distances) or functional ones (escape routes control, accessibility for the disabled). However, it is evident that there a various areas of investigation involved.
The opportunity of a methodology development results to be very interesting.
In the traditional design process any type of verification can only be performed by sampling. On the contrary, the opportunity of automatically implementing the requisites controls allows to make a wider verification, thus allowing a different approach.
The creation of tested and relatively reliable databases relative to regulatory requirements allows to add repetition and objectivity to the control to be performed. This would work well in the case of a tender award for a public work.
Thus, the opportunity of automatic or semi-automatic verification on the building virtual model offers further cases of efficiency and quality. This shows how the BIM methodology and technology is going towards new ways of conceiving the building and construction sector.