The Power of by Raoul Karp, S.E

TThehe PPowerower ooff Computer Aided Design TTechnologyechnology

Digital solutions are not new to structural engineering. Technology has provided the profession with numerous digital problem solving tools. From design to construction, engineers rely on the computer to bring structural ideas to reality. And, we all know that our technological edge is not stagnant. On the contrary, technology often changes more rapidly than we may be comfortable with. The new paradigm in the structural engineering environment is Electronic Data Interchange (EDI), a tool intended to bring all of the project team members together… digitally. In theory, the concept makes sense. In practice… the structural engineer is still sorting out a comfort zone. We went to the industry to learn more about the technology and its impact on the business of structural engineering. The following three articles provide a window into the EDI concept, and a glimpse into how the structural engineering community is adapting. CComputeromputer AAidedided DDesignesign More than Just an Electronic Pencil and Paper The Power of By Raoul Karp, S.E. and Brian Quinn, P.E. For years now, engineers have successfully legal document production, that CAD should been using CAD as their Computer Aided evolve into this more extensive hub into which Drafting tool. The advantages of CAD other disciplines would integrate. As illustrated have been well established and proven, with below that is essentially what is transpiring with effi ciencies in drawing reuse, organization, products like AutoDesk (AutoCAD Building Technology revisions, quality and consistency to name but System, Architectural Desktop, Revit), a few. But if you haven’t already, you might Bentley (Triforma), Graphisoft (ArchiCAD) start thinking of CAD as more than just an and Intergraph (FrameWorks Plus) vying for electronic pencil and paper. In recent years dominance in this 3D BIM world. there has been signifi cant advancements Maintaining a single model has several made in the construction fi eld into making signifi cant advantages, many of which have CAD products fulfi ll their potential, not just already been proven in practice. Interference likely to review shop drawings. Also, many as drawing tools but as complete repositories checking and visual verifi cation of as-built are of the opinion that they feel better with for the storage, visualization, coordination, and construction conditions will facilitate someone else starting from scratch and re- manipulation and extraction of relevant early problem identifi cation and avoidance. inputting the whole model because they feel building information. This concept, coined A coordinated, accurate 3D model from errors will more likely be caught this way. the Building Information Model or which anyone can pull the information they However, these concerns have, for the most BIM, revolves around a single 3D model need will make for a more effi cient process, part, been found to be without merit. In fact, most commonly located within the CAD less duplication of effort, fewer case studies have shown that fabricators have environment. But for all the talk, there are still been able to spend more time reviewing the many questions about just what is BIM, what “…3D model from which anyone can shop drawings and looking at the more diffi cult challenges do we face to a more widespread pull the information they need…” areas in more depth, because they didn’t need adoption of this technology, and of course to waste valuable time on re-inputting tedious what benefi t is this to the engineer. To better copies of identical information and fewer data such as member sizes. answer these questions a short description of opportunities for miscommunication of intent. In addition, the creation of an accurate the state of the BIM technology is necessary. Companies like Cary Engineering Consultants 3D model in CAD can open up other service Just What Is BIM? in Greenville, S.C. have successfully used alternatives. Already several prominent fi rms are this technology to their advantage. William investigating or offering value added services, The BIM process would have all disciplines Cary, vice president and general manager of like detailing as part of their practice. In today’s working off one single model where the Cary Engineering has said, “(EDI) saved time marketplace, where all parties are pushed to entire information for a building structure on coordination, shop drawing review and perform “better, faster, and cheaper”, technology (architectural, structural, mechanical, electrical, reduced errors”. and EDI have played a key role in some schedule, costing and even usage) could be This theme is repeated in many projects that companys’ ability to work more effi ciently. stored, managed, coordinated, visualized, currently use EDI. However, many engineers However, for all its benefi ts, the adoption and dissected and extracted. The model would not have expressed concerns that fabricators will use of this technology is still not widespread be a collection of lines, but rather a collection of simply want to “click the button” and be less within the structural engineer and building electronic objects that each know how they look, industry. So what is keeping engineers where they belong in 3D space from embracing this technology in greater numbers? Besides the traditional “…a collection challenges associated with a signifi cant of electronic objects…” paradigm shift, four common reasons we hear against adoption of a single and most importantly how they relate to other building model in any form are: entities in the model. Individual consultants a. Legal / Liability Issues of Ex- typically continue to use the software that is changing Data. most effi cient for their domain, but through b. Interoperability and EDI stand- proprietary or standardized Electronic Data ards for all construction materials Interchange (EDI) they would communicate and software vendors. the necessary information back and forth to c. The need to create full building the BIM. It stands to reason that as all the analysis and design models. disciplines involved in the design typically use d. Keeping analysis models accurate CAD as their medium of communication and and up-to-date. STRUCTURE magazine • July 2004 27 Legal and Liability Issues information related to both steel and concrete advancements and feature enhancements in structures. Unfortunately IFC is not yet widely programs like ROBOT, STAAD, ETABS and On the legal issue, engineers have said their implemented in most structural engineering RAM Structural System are starting to allow insurance carriers have many times advised software commonly used in North America. engineers to effi ciently model, against giving electronic fi les to other parties. However, given the recent advancements Many engineers who do give out EDI fi les may in structural software’s ability to allow the “…rarely does the engineer require the receiving party (in most current engineer to effi ciently model, analyze and create a single building model.” cases this is typically the fabricator) to sign a design a full concrete building structure, “waiver” agreement, where the receiving party including completely specifying reinforcing, analyze and design entire concrete structures. recognizes the fi le is simply an aid to help them the latest IFC standard is timely and welcome. These programs allow engineers to fully but may have inaccuracies (as described in the Current successes in the transfer of concrete design gravity and lateral systems and allocate CASE Document #11). The AISC Code of reinforcing information to all Standard Practice addresses this members and components of the issue as well in Section 4.3, Use of structure. This process will need to CAD Files and/or Copies of Design be made effi cient enough to allow Drawings. In section (b) it states, all the information to be specifi ed “The CAD fi les or copies of the by the engineer, and hence become Design Drawings shall not be valuable for EDI. considered Contract Documents. In the event of a confl ict between Is the Model the Design Drawings and the Up-to-Date? CAD fi les or copies thereof, the The last challenge we commonly Design Drawings shall govern.” hear relates to the engineer’s It also goes on in section (c) to tendency to essentially abandon the re-iterate that providing these analytical model at some juncture electronic fi les shall not obviate in the process. That is, analytical the fabricator’s responsibility for Advancements in Data Exchange models are also not always kept up- proper checking and coordination to-date all the way to and through of dimensions, etc. While legal construction. Typical reasoning for precedent and regulation issues this is that most late changes to a continue to evolve and be job may have little effect on the addressed formally, engineers who reinforcing information in the United States is overall analysis, and changes of this nature are currently using the technology establish mostly limited to proprietary solutions, such are more easily picked up in the construction responsibility on a project-by-project as the RAM Concrete to aSa Detailing link. documents rather than in the analytical model. basis with great success. However, for widespread adoption of IFC or Another important reason is that their clients “…have fabricator and CIS to handle concrete structures, additional do not typically pay consulting engineers structural engineering concrete industry initiatives will be necessary. for the extra time needed to keep these fi les software adopt the standard.” Full Building Models accurate. This is where a design-build project team might recognize the benefi t to other A third, and greater impediment, to team members, and hence be willing to do Interoperability and EDI adoption of this single building model relates the extra effort that is required. Engineers Standards to the nature of the analytical models structural would need to include updating time in their engineers create. Take a current project we A second impediment to a BIM adoption is fees and could lose projects to competitors are involved in; a fabricator is interested in the fact that for some materials, EDI standards who don’t do this. In traditional design-bid- importing an engineer’s analytical model. are currently not well established or widely build, the engineer most likely has no idea if However, on this two-story building the adopted. CIMsteel (CIS/2) is well entrenched the fabricator who is awarded the project will roof slope was not input to be exact, column in the US for steel structures, in a large part want an EDI fi le. splices were not accurate, column heights thanks to AISC initiatives to have fabricator were adjusted for analytical not geometric What Does the Future Hold? and structural engineering software adopt accuracy and the columns in some cases were The good news is that emerging technology the standard. Concrete and other material oriented incorrectly. Even more apparent should signifi cantly help with this issue. information is currently not part of the CIS/2 is that, for some structure types, it may be Programs such as RAM CADstudio, 3D+ standard. Industry Foundation Classes (IFC) ineffi cient to create full building models for and Structural desktop allow engineers to developed by the IAI (“International Alliance analysis and design. The analysis and design of make changes in an AutoCAD environment for Interoperability”) has also been available a fl at plate, shearwall concrete structure may to their 3D model. By making the changes in for several years, and recently (May 2003) occur in multiple, different software products CAD to the 3D model, the engineer will see has been extended to make new functionality and rarely does the engineer create a single the return on their investment directly since for structural engineers’ use available. IFC building model. However recent technology their construction documents are created 2x2 includes standards for communicating 28 STRUCTURE magazine • July 2004 directly from this model. An added benefi t Triforma allow similar exports of CIS/2 fi les making the CAD 3D model more accurate is that the model in the CAD environment from a Microstation platform. Again, this allows and up-to-date will reap the multi benefi t of is then accessible both for coordination with engineers to make changes in the “CAD” world allowing integration with other disciplines in other disciplines as well as for EDI. These and hence have more accurate models. a BIM, opening the door to additional service products have the additional advantage Given these challenges, what can and opportunities such as detailing, and most of addressing several of our should engineers be doing today to embrace importantly allowing for accurate, effi cient, this technology? While the concept is not new, drawing creation and revisions. “…continued use of this it is only in the past few years that enough of However, for the engineer to stop the process technology should be encouraged.” the pieces have started to fall into place to start at the contract document production stage still to make the application of this technology results in ineffi ciencies in downstream activities. industry concerns related to construction feasible. There have been many success stories By allowing fabricators to use this model as the documents as discussed in the CASE 962 related to the use of EDI in the steel industry foundation for faster, more accurate shop drawing document. Time spent on creating an accurate and, if your project is appropriate, continued creation and manufacturing, you signifi cantly model in CAD is rewarded in the creation use of this technology should be encouraged. reduce errors, provide better communication of construction documents, and result in a At the same time, there may be an increased between engineers and fabricators, receive fewer model that signifi cantly reduces the number demand by your clients to obtain a 3D model RFI’s, and happier clients. For a little effort, the of inaccuracies that might be found in analysis from you for coordination and integration engineer stands to benefi t signifi cantly in their models. The analytical model no longer needs into the BIM. Given that engineers may current practice by considering CAD as more to contain irrelevant information and can be be reluctant to share the analytical model than an electronic pencil and paper… and see optimized for the analysis and design, and not for legal, economic and practical reasons, it it as an easy, effi cient way to build a better team, the detailing. Other programs such as Bentley should be apparent that spending time on project and product.

101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101 AAdvancementsdvancements inin DataData ExchangeExchange The Integrated Model Approach – Multi-Material & Multi-Discipline By Rhett Thompson and Clive Robinson In the building industry - change is a natural progression of “information Product Modeling refi ning” in the design process, as The solution for managing building more precise information is created. information effi ciently is true product When changes do occur, the related modeling. The forerunners of the building objects automatically adapt modeling have been in the mechanical to the new situation. This concept and plant design sectors. Since the early keeps the building object libraries 1990’s, structural steel detailing has made compact, and makes management a remarkable shift from 2D drafting to of the entire building remarkably 3D product modeling. Tekla Xsteel and a easy and effective. few other solutions have played a pivotal Today, the main prerequisites for role in facilitating that change. comprehensive productive BIM Available modeling technology applications are fulfi lled. Parametric solutions can be divided into two Shared Tekla Structures multi-material model: product modeling has a successful different categories – ‘bottom-up’ and Concrete & Steel – Design – Analysis – Detailing – Fabrication track record in the building ‘top-down’ systems. Originally driven industry. Telecommunication infra- by mechanical and plant design, parametric Modifi cation management becomes more structure and Information Technology (IT) ‘bottom-up’ modeling technology was practical with the use of parametric ‘top-down’ systems have developed to the level that designed to create parametric models of modeling technology. This technology was satisfi es the requirements of BIM, and individual pieces. Building models created created specifi cally for modeling buildings, which international standardization processes have utilizing this technology are based upon consist of thousands of objects. In the ‘top-down’ also produced practical interoperability tools independent ‘models’ of individual objects method, the basic objects are fi rst modeled for the building industry. tightly integrated together. This technology without details, which perfectly supports the The fi rst BIM applications have been effectively manages the shape of individual normal requirements of conceptual design. The available for certain segments of structural objects as well as the output generated from logical relationships between building objects are design for some time. ‘Top-down’ technology them. However, complications can arise when created when applying the members’ physical is already in use in the structural steelwork thousands of building objects are used with connections. Connections also defi ne the fi nal industry with Tekla Xsteel. Recently, Tekla complicated linking relationships. shape of building objects. introduced Tekla Structures in which a single,

STRUCTURE magazine • July 2004 29 BIM consists clearly of several clusters of tightly integrated groups of islands. Architecture, plant design, HVAC and Structural BIM’s are clearly independent areas with vital connections to the outside world. Structural BIM is the most essential component of the building process, as the majority of design information is created at this stage. The existence of a versatile BIM solution is not possible without integrating the structural element of the BIM process. Structural Integration The model starts to evolve during the engineering stage, where conceptual decisions of the structural forms are made. The load- bearing structures are designed and input into the model. Analysis & design plays a signifi cant role at this stage, however not in the classic sense of using separate, independent tools. “Over the past three years the British Airport Authority team has been using Tekla products on the Structural BIM analysis/design is not a primary Heathrow Terminal 5 (T5) project in London. T5 is the UK’s largest construction project and is due to be phase in the process, just another output that completed in 2008. (‘Top-Down’ technology has) allowed 3D Structural Steelwork model collaboration between T5 design team members, while at the same time utilizing and developing the steelwork could be generated and maintained through the contractor’s production model” - Nigel Bradley BAA 3D Cad Coordinator. Heathrow Terminal 5 physical model. When changes occur, they are made directly into the Structural BIM model, Advancements in Data Exchange with all analysis & design results and other integrated, software platform from which all solution is to integrate all the existing tools. output updated accordingly. With a Structural types of structures, regardless of material, can be This has been the general target for various BIM solution, there is no need to create and created. international and national standardization maintain separate analysis/design models. Integrated Steel Design (ISD) Applying the Integrated ventures, including IFC, CIS/2, STEP, etc.... At the conceptual design stage, it is also Several successful demonstrations and test essential that the Structural BIM solution Approach projects have occurred, with various results, provide support for all building materials. For The current organization of the building ending up in some software functionality to help analysis and design purposes, a model of the industry is localized and segmented. The with routine work. However, development is entire building is needed. The co-ordination construction process consists of many small still at an early stage, regardless of the signifi cant and management of the detailing work for islands of automation. All parties involved, effort put into the standardizations. The biggest concrete and steel is all the more essential. work co-dependently on individual islands problems are in fragmented information Open interfaces are fundamental for a using different tools. However, the tools do management, and in supporting the “roundtrip” Structural BIM solution, not only from an not speak a common language, platform or of information. To be able to manage constant interoperability point of view, but also from a conventions, so information fl ow between changes, the integrated system should be able to customization and localization point of view, parties is ineffective… clearly a costly obstacle. store all information from each of the integrated although connection and precast Using modern product modeling technology solutions. All solutions within the industry concrete piece design are tasks on some linked islands does not should speak a common language utilizing the same terminology. This would require a huge “When changes occur, they “…the tools do not speak development effort from the solution providers, are made directly into the a common language…” as well as from the standards bodies. Therefore, Structural BIM model…” this straightforward approach does not seem to improve the overall situation if the complete be the most practical solution. that simply cannot be fully standardized in value-chain is not ready to exploit the Likewise, the integration of linked models into the foreseeable future. However, today it is results. Sub-optimization naturally improves CAD software requires considerable effort from easy to use open interfaces, which provide the performance of the specifi c unit, but as the software vendors, and is not a single model the opportunity to supplement the Structural information fl ow is based on manual handoffs, solution. A general CAD platform is an obvious BIM system with plug-in software modules. some information is lost when passing data to solution from an interoperability point of view, After completing the engineering stage, the the next player in the value-chain. This leads but the depth of information suffers. Existing next acting project players are the structural to duplication of work and inconsistencies in CAD platform-based solutions are far from the detailers, who enhance the information information. best-of-breed solutions available on the market, with the same product model. They do not How can all of these diverse tools be integrated and the effort needed to bring CAD-based recreate the geometry of building objects; to form a real solution? The straightforward solutions to the same level may be unrealistic. they just refi ne and supplement the existing 30 STRUCTURE magazine • July 2004 capability to share the same One example close to the actual Structural real-time model. The creator BIM core process is project management. of the information owns that Once Structural BIM is implemented by an information, and has the organization or alliance, it is quite obvious authority to give permission why project management is such a valuable to view, use and change the tool. The real-time model information. This is what Structural BIM is all about - “Changes must be communicated…” a group of automated islands located so close to each other allows accurate information to be shared that there is no practical by all parties, and practical details can be information already created by the engineers. reasons to separate them. managed easier. Any member of the project Real-time integration is extremely crucial at team can check the status of the various other this stage. Changes must be communicated Parallel Process Benefit parties working on corresponding processes to all detailers, engineers and, in some cases, There are several processes parallel to the throughout the lifecycle of the project. back to the architect. The complexity of Structural BIM core process which can benefi t Another example is cost analysis, as information management increases with the from this new model-based way of working, Structural BIM provides an excellent tool for fact that projects in the real world proceed as these are natural parts of the Structural managing costs. It is part of the initial decision- in phases, and are heavily overlapping. The BIM. They are not primary prerequisites for making process and is obviously also linked to complex network of dependency between the implementation of the Structural BIM, the architect’s model. As the structural design the tasks and responsibilities of the different but once Structural BIM is implemented it is process proceeds, the cost composition will players handling the same building objects senseless not to connect them into the same become more accurate and detailed. defi nitely requires a solution with the model.

101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101010101 IntegratedIntegrated SSteelteel DDesignesign ((ISD)ISD) The Engineers Role By Don Engler, P.E.

The technology boom has led to a host of engineering software that is intended to create a 3D model oriented design environment. These new tools, along with Electronic Data Interchange (EDI) are being heralded as the new way of doing business. Today, engineers are right in the middle of this new technology, and are being asked to be an integral member of the 3D modeling team. But what is the Engineers role both from an engineering and business standpoint? And how does the engineer take advantage of this new environment? ISD is the process by which the Engineer produces a 3D computer model during the design phase for use by the rest of project team. This model contains exact Figure 1 “…engineers are right in the middle The completed model would provide a would become an as-built of the completed of this new technology…” tremendous amount of information to the structure, and could be used for building project team, saving both time and money. systems such as environmental controls and geometry and member descriptions, including The different disciplines would be able to security. concrete, steel, timber, curtain walls and other work off the same geometry, thus errors All of this is made possible today with structural materials. The model is used as the that normally exist because of coordination currently available hardware and software. defi ning document by the project team. problems would be eliminated. The model The speed and cost of hardware is no longer STRUCTURE magazine • July 2004 31 an obstacle for the average engineering offi ce. Additionally, software companies now recognize the need to be able to communicate between different applications. History For industrial projects, spatial relationships are of critical importance. The use of a 3- dimensional model for design and detailing has been in use for many years on industrial projects. The industrial design market is often associated with the Engineer acting as the Construction Manager, Purchasing Manager, and as the Design Engineer. This business model allows the engineer to drive the project using the 3D model to manage the associated trades such as mechanical and electrical design. “…there isn’t a driving force to adapt the new technology…” Figure 2 The industrial 3D computer model is then Theoretical Business used to combine all of the components into one model for interference detection. The model Model for ISD becomes the defi nitive document, and the entire In a perfect world, the architect would the project schedule by 20%, and would project team uses the model as a framework for create a 3D model showing all of the geometry, eliminate some of the major issues that often the control of their work. The typical contractual certain member requirements and any other result in delay claims. relationship that exists in the industrial sector special spatial requirements. This model The contract would specify which party is facilitates this information transfer. would then be given to the engineer who would responsible for creating the model and which The commercial and institutional building perform an analysis by importing the model party is responsible for maintaining the model. sector has not yet embraced 3D modeling to into their analysis program. Upon completion In the end, this process would result in an as- the extent the industrial sector has, for various of analysis and design, the completed model built model that the owner could use reasons. These include both the traditional would then be sent back to the architect for in the future. importing into the architectural 3D model. commercial business model and the contractual “…not every member needs to be relationship that exists between the project This process would continue throughout the team. Additionally, there isn’t a driving force design process until both parties end up with physically shown at every location.” to adapt the new technology as there is with a completely coordinated three-dimensional the Engineer in the industrial business model. model of the project. The Issues with ISD Today While spatial relationships are important for The model would then be downloaded to Who makes the model? these projects, it’s not quite as critical as it is for the General Contractor and all subcontractors This is like “Which came fi rst, the chicken industrial projects where the fi t of the contents for their use. For example the steel detailer or the egg”? The architect is the driver of the of the building is at least as important would download the model into a detailing geometry, which may vary between the building as the building itself. program such as Tekla Structures (the new skin and the building structure as being the version of Xsteel) and generate the detail control. However, the architect’s need for “…information from the model drawings with a minimum of geometry related exact geometry is different than the rest of the would be used to create the numerical questions. Figure 1 is from a Tekla Structures project team. The structural engineer typically fi les for use by the fabricator…” model which includes all of the main structural is satisfi ed if the structural geometry is accurate elements that are directly linked to the design to within one inch. Also, for typical structural analysis program. The information from the contract documents, not every member needs The technology now exists with the new 3D model would be used to create the numerical to be physically shown at every location. Many analysis programs, 3D architectural programs fi les for use by the fabricator to automate the pieces are described by typical details and and interface programs such as CIS2, which fabrication process. This same process could schedules. The detailer and fabricator on the allow the various programs to communicate be used for curtain walls, reinforced concrete, other hand, need a model accurate to within with each other. This article will discuss some precast concrete, etc. The general contractor 1/16 of an inch, and one that includes every of the challenges the use of this technology would use the model for scheduling and for piece of steel. The curtain wall fabricator also may have for the commercial market and some special visualization such as for earthwork and needs a very accurate model to determine possible solutions. site requirements. This process could improve precision cuts and attachment points. 32 STRUCTURE magazine • July 2004 Who owns the model? with a lot of architects, question the benefi t This group could work directly for the The word “owns”, for the purposes here, they will gain by the use of a comprehensive Owner or the General contractor, and their has a legal connotation associated with 3D computer model. The usual comment is responsibility would be to collaborate with the responsibility for the model accuracy. The that this will really benefi t the detailer! This project team during the design development. liability exposure would be signifi cant for the is true; however the detailer’s portion of the Their product would be the 3D model. owner of the model. If for example, the curtain project is towards the end of the process and The Modeler would be paid to develop and wall manufacturer relied upon the model for discounts the amount of benefi ts the project maintain the model, and to take responsibility fabrication of the mullions and these ended can derive. for its accuracy. The goal of the modeler would up being fabricated incorrectly, the remedial Until the entire project team can see direct be to assist the project team in development costs and schedule delays would be signifi cant. benefi ts in the creation of a project model, of the model without increasing the costs of The person who creates the model there will not be acceptance of this new way the individual team members. This might should theoretically own the of doing business. Another obstacle with be similar to the physical models that were universal acceptance is that a lot of the project constructed for large industrial projects in the “…engineers feel they should team members are still living in a 2D world, days before computer modeling. Everybody be compensated for this and are not prepared to spend the extra money involved in the project would visit the model, additional scope.” or train their people in 3D design techniques. and use it for discussing their particular issues The main area of agreement is that there can and for planning. model. In essence, the creator would own the be signifi cant project schedule improvements Conclusion responsibility and liability. with proper implementation of this new 3D Currently there are not very many business model. It is easy to see that once ISD is certainly on the horizon; the volunteers! In fact, this is one of the major a model is created, the information could technology is already in hand. There are problems. Almost everybody agrees the model be available sooner than what is currently many engineers and architects who support would benefi t the project but somebody else available through the normal release of 2D ISD and EDI, and some who are currently should create the model. Based on our litigious documents at the end of design process. using this business model. This concept will culture, this is a very real and scary proposition If used correctly, 3D modeling can provide require a change in the way we do business. for all members of the project team. tremendous benefi ts to the project, from the The real question is who will drive this change Who pays for the model? designers through the construction process. and create a business model that will result Most engineers do not fundamentally object The architect and engineer could pass the in benefi ts for both the owner’s constructed to creating a 3D structural model. Their main model back and forth on an iterative basis project and the design/construction team. concerns are as stated above, the liability issue, to redefi ne the structural analysis and the and of course “How do I get paid for this”. structure itself. This would allow structure One could argue over the amount of extra optimization without delaying the project. work 3D modeling would require. However, The construction manager could also benefi t without question it is extra work, and by using the model as a relational database to engineers feel they should be compensated for track and control the project through reports this additional scope. Not all projects require and model visualization. a 3D model, and the benefi ts for the design Projects that are primarily driven by engineer may not be readily apparent. geometry are ideal for taking advantage of 3D

Structural engineers normally do not computer modeling. The new Seattle For Advertiser Information, visit geometrically modify their analysis and design Central Library (Figure 2) is a computer models late in the design process, unless the engineer determines the modifi cation “…question the benefi t they will will impact the actual design. Simple framing, gain by the use of a comprehensive such as for fl oor openings, are not typically 3D computer model.”

added to the structural analysis model. These www.structuremag.org types of inconsistencies would need to be good example of a project where the structure controlled if there were to be a “Master” 3D geometry and the structure surface control the model of the entire structure. Maintaining design. A 3D model of the structural steel the fi nal model to account for all pieces of the was created during the shop detailing phase, structure will increase the engineer’s costs to however the project could have benefi ted ensure that the model is accurate. greatly from having the model created during Who benefi ts from the model? the design process. There is agreement that the future will Possible Solution? likely be a single-3D-model world, and the Until there is universal acceptance and the entire project team will plug into it and all 3D benefi t to the project team is obvious, will benefi t. The problem today is that not a possible solution may be the creation of a everyone agrees that ISD will benefi t their new team member, the Modeler, whose sole particular industry. Certainly engineers, along responsibility is the creation of the 3D model.

STRUCTURE magazine • July 2004 33