METHOD OF DETERMINING STRESS-STRAIN STATE OF ROCK MASS BY METHOD OF PARALLEL WELLS Russian patent published in 2019 - IPC E21C39/00 

FIELD: mining.

SUBSTANCE: invention relates to mining, namely to method of evaluation of stresses of rock mass by method of parallel wells, is intended for determination of stress-strain state (SSS) of mine rock massif on coal and ore deposits, as well as concrete massif and can be used for evaluation and forecast of stability of mine workings during mining operations. According to the method, a measuring well is drilled at a controlled section, and a measuring instrument is installed in it, which is used to measure values of radial displacements of the walls of the measuring well. Unloading well is drilled parallel to the measuring well, and after completion of drilling of the unloading well, a loading device is installed in it, by means of which the walls of the unloading well are loaded with uniform pressure, after which values of radial displacements of walls of measuring well are measured and from dependence of values of radial displacements of walls of measuring well on pressure applied to walls of unloading well, elastic characteristics of massif of rocks are determined, from which are determined SSS rock massif at the place of measurements. At the same time the points of installation of the measuring instrument in the measuring well are determined based on the results of the analysis of the core drilled out from it, as well as by means of video shooting or endoscopic examination of the state of the surface of its walls. Installation of the measuring device is carried out on sections of solid massif without disturbance of continuity of the surface of the walls of the measuring well and in the absence of cracks in it. During installation of measuring instrument its orientation is performed in plane perpendicular to longitudinal axis of measuring well. When measuring, a measuring device is used with a digital device and possibility of automatic recording and transmission of data in form of a digital signal in real time from the place of measurement to an interface system for collecting, storing, processing, converting and interpreting the obtained data in the form of a personal computer (PC) with general and applied software, including calculating elastic geomechanical model of behavior of analyzed massif of rocks in digital form. Measurement of values of radial displacements of measuring well walls and their automatic registration in real time mode is carried out in at least four differently oriented measurement directions with instrumental and visual control on PC screen of their changes in drilling process, and uniform loading by pressure of walls of the unloading well by load device. Complex elastic characteristic of rock mass is determined with preliminary evaluation of obtained data quality. After determining SSS, with a positive preliminary evaluation of the quality of the obtained data during pressure loading by the walls of the said unloading well, instrumental control of mutual location of said measuring and unloading wells in plane perpendicular to longitudinal axis of measuring well, and visual control on PC screen of changes in their mutual location during drilling. Based on the results of determination of actual mutual location of the above wells, in case of their parallelism violation, the value of the complex elastic characteristic of the rock massif is refined at the place of measurements taking into account the actual geometry of the wells. Process of real-time measurement of values of radial displacements of the walls of the measuring well is stopped at the moment when their measuring discontinuities are registered by the measuring instrument. Using the computer program in the interface system, the obtained radial displacement values of the walls of the measurement well are automatically used for preliminary estimation of determination results SSS directly at its location and compared with previously obtained corresponding data in previous measurement location. Based on the comparison results, a decision is made on the expediency of further research SSS massif of rocks throughout the depth of the measuring well.

EFFECT: high accuracy of locating deformation localization zones.

1 cl, 7 dwg