Automatic BIM-model creation of bridge structure using 3D-laser scanning, algorithms and parametric modeling

Abstract

Bridges have a crucial and huge role in the safety of the public. An important aspect in maintaining the safety of a bridge structure is to have access to a BIM-model that can be used in analysis and facility management. Long-span spatial curved bridge structures with circular pipe components are widely used in engineering. Measuring the overall alignment of long-span spatial curved structures with circular pipe components quickly and accurately is an important aspect that increase the effectiveness of creating digital twins. This thesis has an approach to find a method to measure this overall alignment in an accurate and quick way.

The method in this thesis is applied to a real case study which is a pedestrian bridge located in Oslo, Norway. The bridge consists of curved steel members at top chord and circular pipe components as struts.

The method implements terrestrial 3D laser scanning of the case bridge for data collection. The data obtained from the scans has been processed and imported into MATLAB to extract geometry information of the components automatically by applying algorithms. The information and parameters extracted from MATLAB are then imported into Dynamo to generate a parametric driven BIM-model of the existing bridge. The model is compared with the point cloud of the bridge to analyze the deviation between the point cloud and the parametric driven BIM-model.

The results obtained from various operations have a good level of accuracy, but there are still room for adjustments in the method that can improve the accuracy of the results. The case study examination in this thesis was however successful, and it can be concluded that the method applied in this thesis can help to measure the overall alignment of long-span curved structures with circular pipe components quickly and accurately.