TFM Project: Modeling strategy for road works

This interesting TFM prepared by our former student Emilio Camino explains: how to approach a modeling strategy for road works by proposing a modeling structure and checking the functionalities of the IFC.

Today, the BIM methodology has a great development in the world and is even recognized as a central tool in national policies for the execution of both building and infrastructure works. In this sense, there are countries that already consider it mandatory for the execution of projects. However, this is not a reality that is homogeneous in all countries.

In Argentina, although there has been a boost since 2017 with the creation of the BIM Implementation System (SIBIM) and documents, pilot projects, different adoption plans have been developed, BIM requirements are not yet observed in both public and private tenders.

In the National Highway Administration of Argentina, which is the public department in charge of the construction and maintenance of all highways in the country, the implementation began in 2020.

In the development of each of the case studies and pilot projects, it was noted that one of the fundamental aspects in this type of infrastructure works lies in the modeling strategy.

In a road work, it will be required that the model information travel from one software to another on many occasions, without there being, many times, an automated connection of said process. This aspect highlights the importance of planning in detail the strategy to be used to avoid loss of information or compatibility difficulties when the model is under development.

On the other hand, another of the fundamental aspects for a public organization, as well as for a private one, is the possibility of using open formats. This refers to the possibility of using any brand when making a model, as well as allowing the public part, savings in the costs of licenses with the use of free software, which are fundamental axes when implementing BIM.

However, when it comes to road works, as well as other infrastructure, such open formats are under development. This does not mean that it is not possible to work with what already exists, but rather that the focus must be focused and the existing possibilities must be studied in detail.

In this way, this work aims to address the two topics mentioned, proposing a modeling structure and checking the functionalities of the IFC for road works.

Project description

The work consists of modeling a preliminary project for an urban road work bounded with the BIM methodology in the city of Sarandí, Argentina.

To do this, a bridge will be built to connect the roundabout of the commercial area with the residential area (yellow arrow), generating another roundabout on the other side of the Sarandí stream and from there connecting with the different urban streets.

It is then proposed to model the digital model of the terrain, the different roads and the roundabout, the crossing bridge, as well as the transversal drainage works and the signaling, obtaining the metric calculations of said model and carrying out a simplified BEP about how it was made the BIM model from the templates of SIBIM Argentina and, finally, generate the deliverables in IFC format, evaluating the possibilities of the latter with the advances to date.

Previous considerations

It is worth noting that to carry out this work, there was only an active license of a specific brand, so all the development has been carried out with the software of this company.

That is why the conclusions and the validity of the proposal made here are part of the possibilities offered by these programs.

However, there are others, which have different virtues and limitations, that work in a different way and that must be analyzed in detail, to make another modeling strategy proposal and to evaluate the functionalities of the IFCs, but that exceeds the scope of this work. .

Objectives and scope

Prepare a limited urban road preliminary project using the BIM methodology

Propose a modeling strategy from the conception of the work to the computation of each of the work items.

Prepare a simplified BEP, where the main modeling criteria are established, following the templates of the SIBIM of Argentina.

Generate the deliverables in IFC and determine the functionality they currently have for road works.

Definition of CDE

To start with the modeling, the One Drive cloud was defined as a common data environment where all the files will be stored, even their archiving and communication.

Said CDE will have a project nomenclature as established in the BEP (2021-4567-01-AUA001-CONEXIóN VIAL A° SARANDí).

Regarding the Structuring of Folders, it will be carried out as follows:

Modeling Strategy

To carry out the modeling of the project that involves from the digital terrain model to the final metric calculations, the following strategy was defined, which is composed of 4 modules: SITE, WORK, FACILITIES AND COORDINATION

To make the site model, we began by defining the Coordinate system in Civil 3D and defined a study surface with polygons that will later be used to generate the Infraworks model.

Satellite images and rasters from the National Geographic Institute and GIS data were incorporated into this generated model, and the environment was worked on and defined.

Then, using IMX format, it was imported into Civil 3D, where the surfaces were adjusted, and the topographic surveys were incorporated, to finally obtain the digital model of the terrain. In addition, satellite images and plans of existing facts were included.

Once the necessary corrections were completed, the surface, as well as the survey of the environment, were incorporated into Infraworks, where the site of the work to be carried out was finally defined.d survey.

From the Digital Terrain Model and the survey of the environment carried out in the site model, they were incorporated through a shortcut to a new Civil 3D file, where the geometric design and basic work of the roundabout were carried out.

For this purpose and to avoid large files, this task was divided into two, on the one hand, the geometric design model where the planimetry and altimetry were defined, and on the other hand, the basic work model, where the pavement structures and type profiles.

All these models were incorporated into Infraworks, where the bridge that crosses the Sarandí stream was defined based on the component roads. There, all the previous pre-dimensioning was carried out, small modifications were made, and then it was exported in IMX where, from a Revit complement, it was possible to finish defining it, incorporating information and even defining the reinforcement.

Regarding the coordination of all these models, it was done through Navisworks, as well as through Civil 3D, where all the major works of art detailed in Revit were incorporated, and it was verified that everything was correctly defined by performing analysis of interference.

Work Model:

For the modeling of the transversal drainage works, in a first measure, the families corresponding to the types of sewers were made according to the type plans in force in the National Highway Administration.

In order to place them in the corresponding georeferenced space, the shared coordinates were used, for which another file was generated in Civil 3D, where their locations and the corresponding input and output levels were defined.

Then in Revit, the coordinates were established, and the CAD was imported with the mentioned information. The culvert families were placed, each with its corresponding extension and elevations.

Coordination Model:

Finally, two coordination models with different functionalities are proposed. On the one hand, a Federated Model in Infraworks, which allowed to carry out everything related to visual and presentation, for the generation