Augmented-reality visualizations of bored pile construction

Bored pile construction entails the use of different construction methods and equipment to excavate in various geological compositions. Application of visualization techniques in underground construction is often associated with high cost while delivering limited benefits to construction engineering. In this research, we applied two augmented-reality visualization techniques namely, Photo-AR and ARToolKit, on a practical building site. Photo-AR is enabled by analytical computing algorithms based on surveying a limited quantity of control points on site. Geo-referenced 3D bored pile models with geological parameters highlighted in specific color schemes are first immersed into site photos showing both ground and underground conditions. Method productivity data including geological compositions, construction methods and time records are presented in the form of production lines to further augment the visualization. The final AR photos resulting from Photo-AR analytically merge both the real world and the virtual world in three dimensions into one seamlessly integrated view. In terms of the ARToolKit application, location markers in the photo frame are digitized into a virtual platform at which the bored pile models on the associated marker locations are placed so as to produce AR effects. The pile models registered in both Photo-AR and ARToolKit applications are identical to enable method comparison. It is found that the Photo-AR is ideal for as-built surveying and modeling in support of progress control and quality checking, while the ARToolKit is instrumental in dynamic site layout planning and heavy equipment positioning before and during construction. In conclusions, we propose a Real-time Photo-AR framework aimed at advancing AR to cater for application needs in construction management practices.