Enhanced Construction Progress Monitoring through Mobile Mapping and As-built Modeling

Construction projects are often suffered from time delay and cost overrun, unavoidably leading to underperformance and low productivity of the construction industry. Inadequate monitoring of construction progress is one of the key factors behind this scenario that has a detrimental effect on subsequent construction activities. Recent development in 3D Building Information Modeling (BIM) and laser scanning technology has made it possible to actively monitor construction progress. This paper aims to obtain timely and accurate progress information of construction activities through integrating mobile mapping techniques with as-built BIM. A novel method of construction progress monitoring using Simultaneous Localization and Mapping (SLAM) and Scan-to-BIM approaches is presented. Having updated as-designed BIM model as well as construction site scan data, Hausdorff distance is introduced to filter out the noise and extract elements of interests from the mobile scan data. The extracted elements are then converted to as-built BIM model and compared with as-planned BIM model. Python script and Dynamo programming are used for color codes to indicate status of activities and obtain related progress percentages. A case study was conducted in the Engineering building at the University of New South Wales (UNSW) to obtain real site scan data. The result shows that the method has achieved an average of 95.44% accuracy in estimating progress percentages. In addition, the take-off quantities from the as-built BIM model could be used for several purposes, such as construction schedule update and material procurement.