Ground-Breaking Solutions: BIM for Earthworks

Iain Stewart
Finding ways to visualise and quantify earthworks has always been challenging. Innovative solutions are now possible, as earthworks can be modelled in 3D for incorporation into a building information modelling (BIM) system.

BIM has rapidly joined the mainstream approaches for the architectural and building industries, but has seen slower adoption in the civil engineering field. The tools have been available for some time, but most project managers and commercial managers have only recently embraced them for civils works. It’s a positive step towards better delivery of all aspects of civil engineering projects, including earthworks materials movement, measurement and management.

Transforming Earthworks Management

Achieving a viable, successful project often starts with managing the earthworks accurately and efficiently. If your project solution requires the current topography to be changed at some stage, it’s necessary to measure and interpret the extent of that change. Traditionally, this has been difficult, but specialist BIM tools are now transforming the way these challenges are handled. It’s possible to model and analyse earthwork changes accurately, producing estimates of excavation and fill volumes. This ensures that the earthworks are properly understood – no under or over-estimating - and their design is optimised.

The Right Material at the Right Time

In commercial terms this means optimising the site in order to achieve a cut/fill balance, reducing expensive offsite disposal and minimising instances of material being handled twice. There are also sustainability considerations, to minimise waste, re-use materials where possible, plan the proper management of contaminated soils, and ensure compliance with environmental regulations.

The 3D model can enable the earthworks volumes to be balanced, but detailed planning, estimation, programming and careful management of site-won materials will also be needed. In combination this approach ensures that the right material is available at the right time, to meet required fill specifications and to enable works to proceed as efficiently and as cost effectively as possible.

Moving Forwards

Continual development of BIM tools will lead to a holistic site appraisal and planning process that becomes more efficient, through enhanced geological modelling techniques and optimised site configurations with detailed quantification analysis. This is helped by the recently improved interface between Revit building design software and AutoCAD Civil 3D civil engineering design and documentation software. I anticipate that we’ll increasingly see BIM used not only for site excavation works but also for the whole site infrastructure – including, for example, site entrances, and connections to power, water, drainage and telecoms services.

Reduce the Risk in the Ground

Prior to investing in a BIM model for your project, Faithful+Gould can assist in the planned site investigation and data acquisition campaign. We can maximise the benefit of that data with an efficient earthworks-enabled model to reduce the risk in the ground for your project. Where BIM is not being used across the project, there is still merit in using it for the earthworks, where the site topography is to be changed. We are already using these methods in several sectors, bringing real benefits for our clients’ construction and infrastructure projects.

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