BIM – Digitalisation in the construction industry

BIM in hydraulic steel construction

In 2015, the German Federal Government adopted the Step-by-Step Plan for Digital Planning and Building model from the Federal Ministry of Transport and Digital Infrastructure (BMVI), which is designed to promote the introduction of BIM in Germany. Building on this, the BMVI commissioned the BIM4INFRA2020 Working Group in 2016 to determine the conditions for the implementation of this step-by-step plan. Other countries like Great Britain, Singapore, the USA, the Scandinavian countries and the Arab oil states have been using this method for a long time. The step-by-step plan is comprised of pilot projects and funds for developing standards, guidelines and models. The federal waterways and shipping administration have been running an kick-off pilot project (replacement new locks in Wedtlenstedt) in the area of hydraulic steelwork since 2017. As a further pilot project, the construction of Luneburg lock is also planned using the BIM method. The BIM method has been regularly used on infrastructure projects since 2020.

 

In order to stay one step ahead of the trend towards BIM, we at DriveCon GmbH have already addressed this topic in detail. We have been planning projects using the BIM method for some time now and we are also well equipped with the necessary software (Revit MEP and Navisworks from Autodesk). What is more, several internal projects are already underway within the engineering communities that we belong to in order to gain further experience. Use of the open IFC format for data transfer has started to emerge in waterways and shipping administration. This does not present us with a problem either, because we can exchange data in all standard formats. This all makes us ideally equipped to deal with BIM projects.

 

 

3D model, geometry and attributes

The idea behind BIM is to create a multidisciplinary virtual building model and to use it to witness the entire life cycle of a building - from its planning, construction and maintenance to its disposal or modernisation. At the beginning of a project, the contracting party is required to write what is known as the CIR (Customer Information Requirements). This document is a kind of requirement specification and describes, among other things, the goals of the project, the BIM services expected (BIM use cases) and the requirements of the project management processes with BIM. The CIR also serve as the basis for preparing the BIM Processing Plan (BPP). This is drawn up by the planning community and explains how the BIM use cases described in the CIR are implemented or fulfilled.

 

At first glance with BIM, it often looks like we're just creating a three-dimensional model of the electrical engineering for a building, rather than just the 2D plans we did before. BIM encompasses much more than the "mere" creation of a 3D model, however, because on its own it comes nowhere near exhausting all the possibilities that BIM provides. It is essential that we provide each object with a geometry (Level of Geometry, LoG) and attributes (Level of Information, LoI) that provide information about dimensions, properties and material etc. We also establish a relation between the individual components. Doing so makes it possible, for example, to link a light switch to a door. Then if the door is moved, the light switch also moves automatically so that it is always positioned next to the door.

 

 

Interdisciplinary collaboration for consistent planning data

The focus with BIM is placed on Interdisciplinary cooperation between all the companies and trades involved so that a digital image of the building is created. The fact that we work together on a single model with structural engineers, civil engineers, mechanical engineers, structural and object planners, etc., means that the data is always up-to-date and collisions can be detected and resolved promptly. If a wall is moved, for example, meaning that one of our control cabinets can no longer be positioned in the intended place, the software informs you of this problem the next time a collision review is performed. The planners concerned are informed of the error by means of BCF (BIM Collaboration Format) and can rectify it directly.

 

At the same time, as is the case with conventional planning, there is no need to make changes to a large number of documents and plans and by doing so expose yourself to the risk of errors during transfer. If use is made of BIM, all floor plans and sections etc. originate from the same database, therefore ensuring they are consistent with one another at all times. Another advantage: BIM models are also machine interpretable, in contrast to plans, so it means that we can initiate evaluations if we so wish. This means, for instance, that we can query whether an illuminated sign is planned for above each escape door. What is more, the data can be exported and used, for instance, for tender lists.

 

If we include the time dimension in the 3D model, it creates a 4D simulation. And if we also take the costs into account in addition to the time aspect, then we refer to it as a 5D model of the electrical engineering for the building. This allows the entire construction process to be planned and visualised and the quantities and costs for resources to be calculated.

 

 

Challenges and advantages of BIM

The fact that we create the BIM basic model for the electrical planning in the preliminary and draft planning stages and this step takes a significant amount of time, it means part of the planning effort within the service phases for the Official Scale of Fees for Services by Architects and Engineers (HOAI) is shifted forward. The scope of the data generated and its management also present further challenges. Particularly with major projects where extensive amounts of data are created that need to be managed, i.e. most hydraulic steel construction projects.

 

Does all that sound pretty complicated to you? Well it is. Particularly at the start of the project, because a large number of agreements have to be made across companies. Over time however, the advantages are well worth the effort, even for you as a customer or operator. The fact that everyone involved is working on a single model and data management is centralised and therefore always up to date results in a higher planning quality at an early stage of the project, from which you benefit. The data for constructing and managing the building can also be extended into a continuous and up-to-date database for the entire life cycle of the building.

 

Definition of BIG BIM, little BIM, open BIM and closed BIM

If the data and models developed are used across the various trades – as provided for in the BIM approach – the result is "BIG BIM". Its counterpart is "little BIM", which means that BIM is only used as an isolated solution within a planning office. A further classification can be made with regard to the software used: we speak of open or closed BIM depending on which software solution is used and how “open” it is.