What is Clash Detection and How Does BIM Help?March 30, 2021 0 Comment Category: BIM Modeling Coordination
Construction has always been an incredibly complex industry, with innumerable moving parts, elements, and people working on the same project all at the same time. It’s only natural that at some point there may be issues due to that sheer complexity. Modern construction projects often involve multiple stakeholders and tradespeople like investors, architects, structural engineers, suppliers, and all manner of contractors in any field you can think of. When you combine the web of involved workers with the need for efficient work and the desire to complete a project by the estimated time, it’s easy to see how clashes may come up. Building information modeling, or BIM, is a recently-developed modeling process that integrates clash detection as an essential element. Interested in seeing how BIM clash detection has improved our projects? Visit Smarcon’s Projects page to find out for yourself.
Before going over how building information modeling improves clash detection, a general refresher of BIM is needed. Contrary to what you might think, BIM is not one single tool, software, or equipment. Building information modeling is a process that encompasses the entire lifetime of a construction project, from conception to completion and beyond. The core idea of BIM is based around a revolution in building modeling; construction projects have used 2D and 3D models of buildings for centuries, but a model created using BIM is different. A BIM model is created and stored in a digital workspace that all involved stakeholders can access and work with in real-time. This synchronized work is combined with an incredible density of information not seen in traditional models. These revolutionary advantages allow BIM projects to detect and avoid clashes much sooner than when using traditional methods.
Clash detection is a term used in the AEC (architecture, engineering, and construction) industries, and it’s fairly self-explanatory. The term refers to the practice of detecting where elements in a construction project may intersect and interrupt work. Clashes are generally separated into three categories: soft clashes, hard clashes, and 4D (or workflow) clashes.
A soft clash is a clash primarily in spatial terms. Soft clashes are generally less consequential than hard clashes, and are generally due to construction elements being placed without regard for other elements. Examples of a soft clash may be:
A column blocking access to a doorway
A maintenance corridor being blocked by piping
Elements placed in a way that breaks safety code.
The high-detail of BIM modeling software can help detect and avoid even these minor clashes. Commonly used BIM software allows users to input dimensions of each element and can even allow users to create custom parameters to match their own regional building and safety codes.
A hard clash is the simplest yet often most problematic type of clash. A hard clash is when two elements intersect with each other or directly occupy the same location. In a building model, this can take almost any form:
A steel beam jutting out into a room
Plumbing and HVAC piping running along the same path
Air ducting directed through a load bearing column
As you can imagine, a hard clash can create disastrous work slowdowns if not detected during the modeling phase. BIM software will detect these clashes and notify users automatically, greatly reducing the need for re-work.
4D, or Workflow Clash
Workflow clash is a clash in the fourth dimension: time. One of the essential steps of BIM is 4D scheduling, which is the addition of a schedule to the 3D model that stakeholders are working with. A 4D clash might be:
Large deliveries scheduled for the same date and time
Different trade teams working in the same location at the same time
Work scheduled on an element before that element is to be completed