AEC Reviews Tekla Structures 19
The latest release of Tekla’s structural BIM tool touches the entire building process from design to construction.
By: AEC Magazine
Tekla Structures started out as a steel fabrication tool, but has grown into an expansive structural Building Information Modelling (BIM) application. Engineers, fabricators and contractors use it to model, detail, fabricate and build — all the way from the air-conditioned design office to windswept site.
To support this broad spectrum of processes Tekla breaks the software down into different versions. There are specific configurations for steel detailing, precast concrete detailing, cast in place, engineering, construction management, drafter and others. Some configurations also feature different operational modes that are appropriate to the user’s responsibility and task.
One reason for the different configurations is to ensure users are not paying for features they will never use. But it is also to streamline what can become a pretty expansive user interface. If you are focused on construction management, for example, you do not want to see the connection macros or detailing tools.
Tekla Structures has a big focus on construction management. The Layout Manager (top right of screen) can be used to prepare accurate model data for export to a field layout device, while the Task Manager (bottom of screen) can help schedule construction projects and track progress.
While each configuration is focused on a specific role, the fact that everything is done in a single environment — in some cases a single model — offers big workflow benefits. An engineer models the structure then a steel detailer adds the connection details, drawings and schedules. The engineer is able to see all of the fabrication information — but is not able to edit or create it.
Tekla has worked hard on the modelling and editing capabilities of the software in the last few releases and it is very easy to build up models around a grid, copying, pasting or arraying objects, linearly and radially.
Version 19 has new ‘SketchUp’-type features: users can grab handles, faces, and planes and pull them around, particularly useful in the formative stages of design.
The software can model pretty much anything: from beams, columns, slabs, and walls, chosen from an extensive library of UK and European standards, to parametric connections and components including curtain walls, staircases, trusses, and precast floors. A custom component editor lets users create their own parametric connections, details, and parts. Macros can also be recorded to automate common tasks.
Users can work in 2D or 3D at the same time, in multiple views, and even start in one view and finish in another. Specific views can be set up to help navigate around huge models, zooming in on a specific phase or storey.Tekla Structures can model and detail multiple materials including steel and reinforced concrete (cast in situ and precast).
The software is set up to support multiple users, working on a single model accessed directly from a server or via VPN. This makes it possible to work on different phases, or to support concurrent workflows, such as change orders, RFIs, modelling and drawing production. ID numbers of objects are tracked to avoid conflicts, but the process still needs to be managed and co-ordinated.
The software supports clash checking, which can handle any elements — steel, concrete, rebar and IFC data. While tolerance checks can be applied to connections to check that bolts can be placed, there are no generic proximity clash tools as of yet. However, this can be done in the free model-based collaboration tool, Tekla BIMsight.
Over the last few years Tekla has invested heavily in interoperability, working closely with Bentley, Autodesk, Graphisoft and others to improve links between Tekla Structures and third party software.
It can read in DGN, DWG, DXF and a host of other formats, including PDF, which has just been introduced in this latest release.
The big emphasis, however, is on Industry Foundation Classes (IFCs), because of its ability to hold object-based data and geometry. IFC files can be read in directly, but Tekla has also written plug-ins for Revit and ArchiCAD enriching the IFC file with a view to making the process more seamless. IFC export is also included.
The software includes some workflow management tools to help manage any changes that are made in the original BIM authoring tool. When re-importing IFC files it is possible to show what is new, old, unchanged, changed, and deleted so users can see very quickly what is different. It is also possible to track property changes, which is becoming just as important as geometry as the industry moves towards Level 2 BIM.
Tekla Structures is not just about sharing data with other BIM authoring tools. It also has strong bi-directional links with many of the leading structural analysis software applications, including Staad.Pro, SAP2000, Robot and Dlubal.
The model can be built in Tekla Structures, sent off to the analysis application with section sizes automatically adjusted in Tekla Structures based on the results. Various parts of the model can be routed to different apps, for example to handle steel and concrete.
Where direct links are not available Tekla Structures also supports CIS/2 (CIMSteel Integration Standards) and SDNF (Steel Detailing Neutral Format).
With a background in fabrication, it is no surprise that Tekla Structures has strong links with CNC machinery via the DSTV format and precast machinery via Unitechnik, BVBS, HMS and SDI.
Tekla Structures might have started out life as a structural steel modelling and detailing tool, but can now handle most materials. When ‘concrete’ was added in the mid 2000s, the initial focus was on the pre-cast market, but this has now been extended to cast in situ structures.
There are a number of new tools in Tekla Structures v19 specifically designed for cast in situ concrete. A new ‘auto union’ feature automatically merges two concrete objects into one. So, if a pad and strip footing are placed next to each other or overlap they will automatically combine into a single volume of continuous concrete. Both objects retain their identity so if it is later decided that the foundations will be pre-cast this can be changed with a single click.
For cast in place work concrete can be split up into individual pours, which is a neat tool for planning the construction process downstream.
Tekla Structures has a range of tools to help contractors estimate the raw quantities used in concrete structures. Pour objects and formwork can be linked to time scheduling using the Task Manager, helping plan how concrete will be built on site and how much the construction process will cost.
Taking control of data
Management of data has become a big focus for Tekla in the last few releases. Version 19 introduces the Object Browser, which is used for viewing or enquiring into the properties of selected objects.
The Object Browser can be used at any stage of the design and construction process: for checking object properties in the design phase or getting quantities out for estimating. Data is presented in a spreadsheet and can also be exported to Microsoft Excel for further processing.
Another tool, Model Organiser, is used to break down models into logical areas. Models can be classified by storey, object type, lots, sequencing and many more.
Model Organiser is helpful for adhering to BIM protocols and delivering properly structured information for COBie data drops. It can also be tied into Tekla Structures’ Task Manager to plan and manage project works.
Task Manager is designed to help schedule projects and track progress, adding start dates, end dates, work duration, etc to the underlying model data.
To date, it has mostly been used by steel fabricators to help plan how to get different phases out, but is now being aimed more at contractors, particularly in relation to the new concrete pour functionality. Here it can be used to quickly price jobs, applying time and cost to tasks based on model data. Or to plan the erection process, including steel, concrete and temporary works.
Task Manager includes bi-directional links to Primavera and Microsoft Project, which is useful if contractors are using a dedicated project management tool.
Moving further downstream, Tekla Structures can also be used for setting out. The Layout Manager can prepare accurate model data, which is then exported to a field layout device. As Tekla is owned by Trimble, the obvious choice is Trimble Field Link running on a Trimble mobile device, which then communicates with a total station.
With Layout Manager it is also possible verify as-built conditions by feeding back information from site. If required, the model can be adjusted to suit site conditions. Everything is trackable and traceable.
Tekla Structures has come a long way since its humble beginnings as a steel fabrication tool. It focuses as much on design and engineering as it does on how steel and concrete will be constructed and managed on site. This has cumulated in this latest release with the introduction of pour management for cast in situ concrete.
As a result, it has a much further reach than Autodesk Revit Structure or Bentley AECOsim Building Designer, which are more focused on design and engineering.
Moving forward, the biggest opportunities for Tekla Structures are undoubtedly at the tail end of the construction process. We would expect stronger links to be formed between the fabrication model and the reality of what is being built on site. The expertise that owner Trimble has in positioning technologies is sure to put Tekla in a strong position in this growing sector, perhaps with laser scanning and point cloud data playing a key role.