Terrestrial 3D laser scanning used to compare the as-build vs design models
It was great to work with Kier Group on this Ministry of Justice UK project where we used terrestrial 3D laser scanning technology as part of a build validation exercise comparing the as-build vs design models. Terrestrial 3D laser scanning collected millions of individual point measurements of the concrete voids and those measurements were then plotted within a single XYZ coordinate system to form a 'point cloud' of the surfaces. Laser scanning the voids helped avoid assumptions, generalisations, errors in interpretation and problems by having a millimetre accurate 3D model of the as-build. High accuracy and precision of the as-build reduced the risks associated with project execution.
At Kier, digital tools are fundamental to bringing certainty to our Design for Manufacture and Assembly (DfMA) approach. At the new build prison at Wellingborough we are making extensive use of prefabrication, assembling seven house blocks using integrated precast concrete components and four-storey-high MEP riser modules. Each houseblock has 33 risers, which have pre-installed mechanical, electrical and plumbing services needed for the cells, reducing the number of activities and interfaces on-site. Prior to the complex task of lifting the risers into position, Kier supplemented on and offsite design and quality checks with on-site digital scanning of the riser shaft to ensure the risers’ fixtures and fittings would align with the components cast into the precast.
We used 3D laser scanning to gather to-the-millimetre 'as built' information of the riser shaft, which was automatically compared against design models, allowing teams to test the complex riser installs in a virtual scenario. This helped us to ensure a safe and successful install.