Normally, almost 90 per cent of drawings in the construction industry are created using two-dimensional drafting tools. The favorite undoubtedly is the semi-automated, 2D CAD software. If we pause for thought here, we realize that we see, think and visualize everything in 3D; but in the construction process use two dimensional drawings, and only when built do we see the project in the three dimensions. This could appear to be slightly illogical, but there was no other way to proceed until object-oriented computer programming was introduced in recent years.
At the beginning of a project, the architect's concept of a building is presented to the owners as a series of sketches or 3D drawings, so that everyone can understand what it would look like, or request changes before passing it on to the engineers along with conceptual 2D drawings. The engineers then translate them into detailed 2D designs from which the Analysis and Design (A&D) of the proposed structure is performed. If the A&D complies with the relevant building codes and is approved, more detailed 2D drawings and specifications are sent to the contractors and subcontractors. Their draftsmen create thousands of detailed 2D drawings so that the structure can actually be built, as the architect and owners originally saw it, in 3D.
What duplication of effort, but that was the only way! Now, what if we started and continued the whole process in 3D? Wouldn't that save time, especially when there are constant changes? Wouldn't it reduce the risk of errors, especially if all concerned are working off the very same 3D model, seeing everything the way it really is while fabrication and construction are taking place?
BIM
Building Information Modeling (BIM) is a method of creating, storing, distributing and communicating all relevant data to everyone working on a project using an intelligent 3D model that is in every detail an exact replica of the project being constructed, down to the very last nut, bolt and washer (Figure 1). Draftsmen need no longer create drawings, as these are generated automatically within the model and can be accessed at any time. The value of the BIM market in the UAE construction industry alone is estimated to be over $ 1.5 billion per year. By using BIM, over 5 per cent of the cost can be saved on every construction project.
Tekla Coroporation
Tekla Corporation, based in Espoo, Finland, is famous for its successful 3D modeling software packages.
Worldwide, steel detailers and fabricators use its Tekla Structures as a modeling, detailing and automated materials listing system. The company, founded in 1966, has 11 offices and over 30 partners globally, and its products are used in 80 countries.
Tekla has led this market for a number of years and developed a clear understanding of the complexities, especially projects in in the Middle East. Its Building and Construction Division is therefore offering more solutions under the Tekla Structures brand. These include Tekla Structures Steel Detailing (formerly Xsteel), Tekla Structures Precast & Concrete Detailing, Tekla Structures Project Manager, and Tekla Structures for Engineering.
In the construction sector, a huge mass of paperwork is generated through a very fragmented information exchange process among those involved owners, architects, engineers, main contractors, subcontractors, civic authorities, etc. Even as the amount to be handled expands, there is increasing pressure on contractors to stick to schedules, improve quality and raise and productivity.
One Model
As an answer to the problem, Tekla developed the "One Real Model" concept where all those concerned can collaborate on a construction project by sharing the same information on one 3D model. For the engineer, it will handle the modeling of the structure, the analysis and design (determined by local codes) and for the contractors the detailing of the concrete, reinforced concrete and steel. (Figure 2). This is Structural Building Information Modeling, which is taking gigantic strides in using computer technology in the construction industry. Its benefits include better cost estimation and control, consistent data integrity, massive increases in productivity, enhanced communication, major reduction in paperwork, and elimination of possible errors during engineering, detailing, fabrication and the pre-empting of on-site differences during erection, greatly reducing costs in an increasingly competitive market.
Construction Industry Currently
The early stages of any project have a very dynamic environment, where the main interaction occurs between architects, owners, and consulting engineers; often, after completing the original design, changes are sought. Once the engineers have made the changes, they repeat the analysis and design process a re-analysis of the structure to ensure that it continues to comply with building design codes.
Once these changes, the checking and cross-checking have been finalized and approved, the new changes are sent back to the contractor and then to any subcontractor, steel or concrete detailer or fabricator to carry out the physical changes. This calls for more paperwork, much updating of plans and drawings and frequent issues of RFIs (request for information) to clarify the changes and to ensure that they are fully understood. The larger the project, greater the number of people and more the paperwork; and growing exponentially is the risk of errors from miscommunication and loss of documents, in the present scenario.
In a multi-storey building a seemingly simple change to the architecture of one floor may cause design changes that affect many other floors. These have to be thoroughly analyzed and the exact effects correctly communicated. This means many drawing revisions and much cross-checking. In a paper driven system, it is a mammoth task involving a lot of time and a lot of people. The difficulties are greater if overseas companies are involved.
And despite the best efforts, errors do occur; corrections have to be made on site, causing delays that may risk penalties for the contractor. Today, everyone in the building industry is under the pressure of tight schedules, which demands increased productivity and quality.
Building Information Modeling provides a foolproof way of handling this vast amount of information with integrity and seamlessly, while minimizing the risks of costly errors. BIM transforms a very fragmented information exchange process among different sections into one of fruitful collaboration by providing easy access to all aspects of the structure under construction. The Tekla Structures 3D intelligent model helps management, consulting engineers and contractors to communicate without the fear of being misunderstood or making mistakes.
The Tekla program creates "One Model" (Figure 4), an exact replica in 3D of the planned structure; it can be accessed and the information it holds shared by all those who have been granted the rights.
How does this work? The 3D model is created on a computer with Tekla Structures software using properties of real materials steel and concrete, for example. Choose the materials to be used from the extensive library of sections in use worldwide, place them on the gridlines and off you go building the model floor by floor. The model recognizes the characteristics and properties of every section that is used and allows access across the Internet. When one of those involved, say, the consultant, needs to make any changes, he makes them, feeds the 3D model into the A&D portion of Tekla Structures Engineering module and checks the analysis and design.
Once the design is acceptable, he downloads the updated 3D model into the Tekla Structures modeler, which then updates all the changes along with the corresponding GA drawings and materials lists. He then provides this same information over the Internet or on a CD to the contractor, to download it directly into the Tekla Structures Steel and Concrete Detailing Module, which automatically updates their 3D model, along with all the detailed drawings for the concrete, steel and the bills of materials.
All the detailer has to do then is add the appropriate joints or connections, from the large library within the TS Model and perform an automatic clash-check to ensure that nothing has been missed. Any further changes follow the same process. The engineers pass on the updated model to the contractor or detailers who feed it into TS Steel & Concrete Detailing Software, which automatically updates the model whenever it receives fresh data. It simultaneously amends the detailed and erection drawings and all associated information, bills of materials etc., which are always available at the click of a mouse. Even CNC data can be directly output to automated cutting and drilling machines, further reducing risk of error. There is no limit to the size of the 3D model or to the number of times that changes can be made.
The Benefits of BIM
One and the same 3D model is used, and being a real model, it is easier for everyone to visualize the structure. Updates are performed automatically and the detail drawings are produced directly from the model, without human intervention and error. There is no redrawing, which becomes routine work for the 3D model. All detail drawings single part, assembly, general arrangement and cast units are available at a mouse click, as are all material take-off lists, centres of gravity - single parts or assemblies, surface areas for painting or tiling, along with all the properties of every material contained in the model and everything is pre-calculated by the software.
RFIs (requests for information) greatly diminish because those who need information have access to the 3D model. With inexpensive TS Viewers, users can fly-through the model or zoom into any section and access any of the required data. Project management information is also available so that management can see, at any time, what has been fabricated, assembled, transported and erected, along with the associated scheduling information. So, in this way it actually becomes a 4D model.
For work together within the structural design, the program provides tight integration within the single shared model. For collaboration outside the design, open interfaces and standard protocols are used. This allows connections to other software packages to add HVAC, piping, plant design etc., to the same model. It is a totally open system that allows other design solutions and ERP systems supporting workflow processes to interface to this 3D model.
A Building Information Modeling solution like Tekla Structures, with "One Real Model" has many benefits.
Quality is maintained and the chance of error is minimized throughout the project's life cycle. There is substantial increase in productivity and significant reduction in costs, enabling more competitive bidding while maintaining bottom-line margins, or more often than not, increased.
© Construction World 2006
