Dizhi lixue xuebao (Dec 2023)
Considerations on the application of in-situ stress measurement and real-time monitoring in deep underground engineering in strong tectonic activity region
Abstract
The concentration, complexity, and significant anisotropy of in-situ stress make it a pressing and challenging issue in engineering geology safety in strong tectonic activity areas. This paper firstly analyzes the application and existing problems of in-situ stress measurement in deep-buried underground engineering in strong tectonic activity areas. Then, it focuses on the application method, technology, and roles of real-time in-situ stress monitoring in deep underground engineering within tectonically active regions. Finally, it discusses the problems that need to be considered in the application of in-situ stress measurement and real-time monitoring. The results show that in the strong tectonic activity area, relying solely on limited deep hole in-situ stress measurements to determine overall stress design parameters for deep underground engineering is inadequate. A comprehensive study of the three-dimensional in-situ stress field is necessary to reveal its spatial distribution characteristics. Different in-situ stress design parameters should be used for different positions of the deep-buried underground project to avoid engineering waste or engineering damages caused by large or small in-situ stress design parameters. In the strong tectonic activity area, the disk core density is inversely proportional to the measured magnitude of the in-situ stress, and the depth range that has yet to form in the cake-shaped core often has the highest in-situ stress and the most concentrated stress, and the deep underground engineering should avoid this depth range. While a major earthquake or major engineering geological problem occurs, real-time monitoring of in-situ stress can dynamically reveal the relative change trend and evolution process of the in-situ stress magnitude of a specific structural site. It can calculate the absolute value of the in-situ stress state in different time domains during the real-time monitoring period without carrying out new absolute in-situ stress measurements. Regional crust stability and deep-buried engineering geological safety risks can be quickly evaluated, and quantitative in-situ stress design parameters and the stress-strain reserved threshold for preventing deformation and breaking can be provided for the damage repair of deep-buried engineering and the risk of fault activity can also be assessed. The research results will offer geological security for the planning, construction, and safe operation and maintenance of major projects in strong tectonic activity areas.
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