Research methods for seismoacoustic monitoring of large underground facilities

Abstract

Large underground mine workings of hydropower facilities created in complex engineering-geological and seismic conditions significantly differ from industrial underground facilities designed for different purpose in their construction, operation and operating conditions. This makes it extremely urgent to organize seismic-acoustic monitoring in order to ensure their safe and reliable operation and prediction of the status of the underground circuit. The solution of this problem requires the improvement of methods and techniques for field observations of the operation of underground structures during construction and operation. In this paper, we formulate the basic principles of the organization of seismic-acoustic monitoring of the rock mass state that contain mine workings. We propose system of seismic-acoustic monitoring of a complex of underground structures, for example, the underground circuit of the Rogun HPP, which is under construction. The paper presents the field observation technique using seismoacoustic methods: seismic transmission and profiling, seismic well logging, acoustic emission method for concrete and boreholes, dynamic response method for assessing the quality of concrete-rock contact, ultrasonic well logging, ultrasonic studies of rock samples and concrete structures. Effective qualitative and quantitative parameters have been determined, which make it possible to assess the degree of change in physical parameters in the internal parts of rock massifs that occurs under the influence of natural and technogenic factors. This is done in order to assess ultimate strain levels and to find indicators of the critical state of the geological environment in problem areas.