Monitoring of structures in shaly rock formation

Abstract

Shaly rock formations, particularly those rich in expansive clay minerals, pose unique geotechnical challenges for infrastructure development. These formations are susceptible to volumetric swelling and deformation when subject to water ingress, mechanical stress and salt concentration, which can lead to progressive structural damage over time. The long-term swelling effect of shale formation in combination of cyclic thermal and environmental changes induce additional stress on the structure in contact with the shale. This paper illustrates the use of a long-term monitoring program aimed at assessing crack growth and crack propagation of an underground structure situated within shale-dominated geological environments in Southern Ontario, Canada. Real-time continuous data was collected over an extended period to reveal any correlations of seasonal thermal and moisture changes and the deformation of the structure. Furthermore, short-term stress responses were determined based on crane live load tests. These provided insight into the dynamic responses of the structure. The analysis of the time-series data led to the establishment of displacement and strain threshold limits, which ultimately enhanced the structure’s long-term performance and safety. The findings highlight the importance of continuous monitoring in predicting long-term structural responses and support the development of early warning systems and mitigation strategies.