Delivering A49 Link Road scheme in 3D environment
The scheme comprises the construction of approximately 2.3km of dual carriageway in Wigan, UK. The A49 Link Road scheme requires the construction of four new highway bridges plus two highway retaining walls. Lead designer BWB specified that from the project’s inception all elements had to be delivered in a 3D environment.
Tekla makes process much quicker than traditional 2D methods
BWB is responsible for the main highway design using Autodesk Civil 3D. The 3D highway design was then provided to Hewson Consulting and Virtual Construction (Hewson/VC) in IFC format to enable the setting out and construction of the bridge and retaining wall structures in Tekla Structures.
Provision of the highway alignment in IFC format gave us a reference when setting out the structures, proving particularly useful when setting out the bridge wing walls to ensure they tied into the highway alignment correctly. By modelling the bridge wing walls we highlighted issues to the highways team in a 3D environment, enabling the problem and solution to be found much quicker than traditional 2D methods.
Hewson/VC have used Tekla to model the structures with a high level of detail incorporating all reinforcement, holding down bolts and bridge parapets. In addition we modelled key existing items in 3D such as land boundaries, services and old bridge foundations.
Modelling large amounts of detail has meant that there are no clashes between the new and existing items. We have also benefited from clash detecting all the reinforcement, ensuring no issues when it comes to reinforcement fixing on site.
To help increase understanding on site the reinforcement drawings were produced with different colours to identify each bar size. This was followed through to Tekla BIMsight with a coloured 3D model that matched the colours shown on the 2D drawings.
We have also given presentations to the contractor highlighting the benefits of using Tekla BIMsight and the 3D model to aid the construction process, focusing on how producing the reinforcement in 3D can help understanding and reduce the errors on site during construction. The construction sequence was modelled in Tekla by splitting the model into phases. This will help the contractor on site to better understand the construction process.
Furthermore, we have modelled elements that interact with our structures. These include ground improvement, and precast prestressed concrete beams, as well as reinforced earth abutments all of which will be supplied by third parties. This allows us to co-ordinate and share information with the third party suppliers through Tekla BIMsight, and aids the detailed design process.
At various stages during the modelling process we were able to export IFC files to share with the BWB highways team. These files were then combined by BWB into a federated model using Autodesk Navisworks, for review and clash detection purposes.
Internally, we have used Tekla BIMsight to produce federated models with the highway information, and issued them to members of the design team. This has enabled team members to check the designs and information being produced during the modelling process. The images for the project were produced in Sketch-up using a combination of the Tekla Structural model and the highway IFC model.
95% of all the construction drawings used Tekla
We have used Tekla to generate 95% of all the construction drawings from general arrangements and setting out drawings down to detailed reinforcement drawings. By generating the drawings directly using the model we benefit from always showing the correct information and not having to track changes through various drawings manually, since they are automatically updated in Tekla whenever changes are made. By setting the model up with real world co-ordinates we were able to establish quickly setting out points and co-ordinates on the drawings at the click of a button.
Ultimate goal is a master 3D model for end client
Ultimately we aim to produce a master 3D model, with all structures, that integrates with the master highway model. This will enable a single source of 3D information to be used in conjunction with the 2D drawings during the construction phase. Our hope is that having built the project once digitally, prior to construction and passing this information onto the contractor, errors will be eliminated on site and the construction phase can reap the benefits of time and cost savings. Post construction the “as-built” 3D model will be passed onto the client to aid the maintenance and operation of the highway in the future.
Note: We are currently still in the design phase of the project and as such the modelling in Tekla Structures is ongoing. To date we have the Smithy Brook Bridge completed and are working through the other structures.
