Mechanics-based digital twin model for structural construction using 3D scanning and FE model updating

Construction control of large-span spatial steel structures faces significant challenges, particularly during the transition from partition assembly to structural closure. Factors such as component cutting errors, splicing inaccuracies, and temperature-induced deformations further complicate this process. Traditional deformation control relies on forward calculations based on design models and cannot establish a closed loop connecting analytical models with as-built structures. To address these limitations, a mechanics-based digital twin model is proposed using 3D scanning and finite element (FE) model updating. Real-to-virtual model establishment is achieved through 3D point cloud data and self-weight compensation; virtual-to-real construction prediction is performed by considering temperature effects and boundary condition transformations. The proposed method is applied to a high-speed railway station in Fujian Province, China. Accurate predictions of the structural deformations and cutting lengths of embedded members in construction are obtained, with an average relative error of 0.25 %.