In the development of practically all potash salt deposits, the study of gas-dynamic phenomena (GDP) is one of the most difficult tasks to ensure mining safety. Sudden salt and gas outbursts, dynamic breakdown, which are accompanied by intense gas release and possible broken rock carry-over into the mine workings, are associated with GDP. Geological preconditions for the GDP development are often the layered structure of the salt rock mass, the presence of interlayers and layers of salt clays. For the conditions of the Usolsky potash plant mine, complex studies of factors that characterize the possibility of gas-dynamic roof fall of the stoping rooms were carried out. In mine studies, free gases pressure and the initial velocity of gas release in the rocks of the roof workings were determined. The obtained experimental estimations were used as a parametric basis for mathematical modeling of geomechanical processes under conditions of a near-contact accumulation of free gas. The deformation of a layered salt mass produced by a room development system was described by the model of an ideal elastic-plastic medium with internal friction. The parabolic envelope of Mohr circles was used as a plasticity criterion in the compression area. In the numerical implementation, the deformation of clay contacts was modeled by Goodman contact elements. Based on the results of multivariate numerical calculations, it is established that the main factors determining the possibility of implementing GDP are the additional gas pressure at the contact, the width of the workingspan, and the distance from the roof to the first gas-containing contact. With multi-level lamination of roof rocks, there is a danger of large sources of GDP formation and the mechanism of successive fall of layers in an instant mode is implemented.
Лучевая сейсмотомография используется в сейсморазведке как один из приемов интерпретации данных. С ее помощью можно восстановить детальную картину строения пород в пространстве между двумя горными выработками. Пространственное распределение затухания или скорости распростране ния упругих волн рассчитывается с помощью линейных интегралов или их аппроксимаций вдоль лучей и воспроизводится в цифровом виде. Решение больших систем линейных уравнений, связывающих измеряемые интегральные параметры и характеристики изучаемых геологических объектов, производится с помощью различных алгебраических алгоритмов. В основу анализа распространения упругих волн между выработками положены представления геометрической оптики. Возможности алгоритмов восстановления проиллюстрированы в процессе обработки экспериментальных результатов шахтных исследований. Метод позволяет воспроизводить двумерное распределение вариаций исследуемых параметров.
