Construction Project Monitoring with Site Photographs and 4D Project Models

Early and accurate measurement of progress is crucial for the success of a project. Early detection of discrepancies and deviation from the as-planned data allow more time for project participants to identify the best solution. Monitoring the construction progress requires the Project Managers to analyze a lot of as-built data. This time-consuming process is prone to error. To overcome this problem, people have started adopting Building Information Models (BIM) for monitoring the construction progress. In this paper, we have discussed how the site photographs, which are readily available at all project sites, can be effectively used for monitoring the progress. The 4D as-planned model is prepared at the beginning of the project. Then, a 3D model is reconstructed from time-lapsed as-built photos. For any given time, the progress can be tracked by comparing the 4D model and the 3D as-built model. The progress data is extracted by superimposing the reconstructed scene over the 4D as-planned model. The reconstructed model allows the as-built photographs to be geo-registered by the 4D as-planned model. As a result of this comparison, the progress data is then visualized in an AR environment. Progress is visualized in the 4D model using a quadrangle visualization scheme. This type of approach presents a realistic understanding of the construction progress and is a very good communication tool between project participants. We have discussed both interior and exterior construction progress monitoring is this paper DOI 10.5592/otmcj.2014.3.5 Research paper