The goal of the Public Works Department of the City of Helsinki (HKR) is to get gradually rid of drawings also on sites. The greatest benefit in an urban environment is not provided by 3D visualization or machine control but management of decentralized maintenance data.
The Isoisänsilta bridge from Sompasaari to Mustikkamaa to be built
next year has been modeled with its environment.
-Data is the gold of today which just has to be mined from the bowels of machines and put to effective use, says HKR Project Manager Ville Alajoki.
In the case of Helsinki, the benefits of machine control are modest because there are so many kinds of pipes and cables buried underground but no exact information available on them. Machines cannot be operated like road rollers where they are located. However, shared databases would provide many types of up-to-date data on assets and their condition useful also to contractors.
– That would require modeling to become routine even in small projects. No learning occurs if BIMs are used only in big pilot projects once in a decade, Alajoki notes.
He calls for proper modeling instructions and agreeing on common modeling methods, which requires communication between the different parties. That would also place designers on an equal footing in bidding situations since the work content would be the same for all.
– Instructions have already been prepared on what is modeled, but they do not tell how to model it.
It is time to make data flow
The Public Works Department of the City of Helsinki has so far designed and modeled about ten bridges and a lot of other infrastructure. For example, the InfraFINBIM project modeled a park with its bridge, retaining walls, earth constructions and equipment. In the case of streets, the usability of input data is being studied, and Vianova is currently charting for Helsinki where data is available now and how technology could be utilized to harmonize it.
Alajoki calls the collection of data on bridges, streets and other infrastructure in common databases asset management. It would create a basis for the utilization of the data in different connections directly from a database – irrespective of whether it concerns the properties, quantities, condition, repair time, or budgeting of structures.
Alajoki expects data management to bring the biggest benefits to life cycle asset management of structures, from budgeting to maintenance. At present, the length and width data of bridges are entered into a bridge register, followed by condition inspection data for budget calculation – and when funding of maintenance changes, an enormous amount of work is required to divide projects into smaller units and make new calculations.
– It should be possible to filter data from databases quickly for the needs of each party, he continues.
Contractors should be active
At the moment, several ways of exploiting these data are being tested, such as machine control, laser scanning, and snow plow service data management. Effective use of different technologies requires getting basic data to flow between systems and update the same asset database.
In bridge projects, modeling is geometrically more demanding than in building construction, which increases the designer´s workload considerably. For example, curved structures are difficult to model and accurate modeling of reinforcement bars requires a lot of manual work. The designer needs to consider what level of detail is sufficient in modeling.
Alajoki would prefer that they as the client did not have to tell contractors how the model should be exploited. Instead, he wishes that contractors would present their own ideas on the exploitation of modeling and would require designers to model accordingly. At present there are as many modeling methods as designers, and the models do not serve all parties.
For more information:
Ville Alajoki, Project Manager, Public Works Department of the City of Helsinki
Phone: +358 40 334 7301, email@example.com