Novel Technologies for Deep-Excavation Digital Construction Records

The creation of underground space is an integral part of urban infrastructure development because it provides a way to accommodate denser urbanization while maintaining the quality of metropolitan life. To be successful, large-scale underground construction in cities must be performed safely with minimal impact on economic activity. A detailed record of construction activity is needed to complement and correlate with measured excavation response. This paper presents novel imaging and software used in conjunction with traditional documentation methods to capture progress of the Transbay Transit Center (TTC) excavation in downtown San Francisco. A handheld digital camera, high-definition hard-hat-mounted action camera, and unmanned drone-mounted camera were used to acquire excavation geometry during progressive stages of construction. Raw two-dimensional imaging data were converted to three-dimensional construction staging models. A social media platform used as a communication tool among project personnel, generated data that were mined for construction-history information. The virtual models and social media data supplemented with field notes and drawings were used to develop a higher-fidelity digital archive that can be used to efficiently capture and preserve detailed construction history.