Multidimensional thorough perception system for surrounding rock disasters in underground engineering and its application

The excavation process in large underground engineering projects faces the challenges of various disasters, and safety monitoring is an important method for addressing these challenges. To ensure the construction safety of the underground powerhouse at the Jinchuan hydropower station, a multidimensional monitoring system was established. On the basis of a collapse accident during the construction process, early warning precursor information was summarized and successfully applied to the surge chamber. (1) A "point, line, plane, and body" multidimensional thorough perception system that is based on conventional monitoring, a tunnel geology survey (TGS) 360 Pro system, seismic wave CT, and microseismic (MS) monitoring was established. "Point and line" conventional monitoring was used for long-term stability monitoring, "plane" monitoring was used to delineate potential risk areas for subsequent excavations, and "body" monitoring was used to strengthen the monitoring of risk areas. Through the collapse of the roof arch at the underground powerhouse, the MS precursory information of the surrounding rock disaster was analysed, and the results are summarized as follows: the number of MS events, cumulative energy and magnitude increased suddenly; the b value and centre frequency decreased; the apparent stress increased suddenly to a large value and then decreased suddenly; and the cumulative apparent volume increased steeply. (3) A multidimensional system was applied to the surge chamber, and the deformation of the surrounding rock was successfully monitored. Corresponding measures were taken to avoid losses of life and property, which indicates the effectiveness of the multidimensional system. The results of this study can provide a reference for similar underground engineering excavations and disaster protection. • A monitoring data-driven thorough perception and early warning system was established. • The precursory information of surrounding rock disaster was summarized. • The thorough sensing system was successfully applied to the surge chamber to realize the deformation warning of surrounding rock.