Перегляд за Автор "Sakhno, S. V."

Зараз показуємо 1 - 11 з 11

Directional fracturing of rock by soundless chemical demolition agents
(On Ching Lo, 2024) Sakhno, I. G.; Sakhno, S. V.; Сахно, І. Г.; Сахно, С. В.
Rock fracturing is one of the main processes in the modern mining, mineral recovery, and energy industry, which is associated with the numerous environmentally harmful influences. Environmentally friendly alternative to conventional fracturing methods is non-explosive technology, which based on using of soundless chemical demolition agents (SCDA). In this study, method of directional fracturing, which based on creating tensile stress concentrators on the hole surface in the required location, was proposed. Considering the influences of additional installation in the borehole of stress concentration cartridge on stress field nearby the hole, a case study of the effectiveness of proposed rock fracturing method was performed in this paper. A numerical simulation was used to study the stress distribution around the borehole with SCDA in different rock types. It was found that cartridge installation leads to the occurrence of the tensile stress concentrations only near to the gap of the cartridge. The value of tensile stress concentration in the proposed rock fracturing method significantly depends on a cartridge gap distance. An increase in the gap distance leads to a decrease in the stress concentration factor. For granite, sandstone and mudstone, relationships of stress concentration factor to cartridge gap distance that was divided on hole diameter were obtained. The equation for calculating of the hole spacing for the directional fracturing method was proposed. The results of the study are confirmed by experiments in-situ on the directional fracturing of rocks in a quarry and in a coal mine.
Floor Heave Control in Gob-Side Entry Retaining by Pillarless Coal Mining with Anti-Shear Pile Technology
(MDPI, 2024) Sakhno, I. G.; Sakhno, S. V.; Skrzypkowski, K.; Isaienkov, O.; Zagórski, K.; Zagórska, A.; Сахно, І. Г.; Сахно, С. В.
The severe floor heave in gob-side entry retaining is the major restriction factor of the wide application of pillarless mining thin coal seams. Reinforcement and stress-relief floor heave control methods are the most promising. However, in practice, floor restoration is widely used. Therefore, floor heave control technology in gob-side entry retaining needs to be improved. This study proposes anti-shear pile technology to control floor heave in gob-side entry retaining. The research was mainly carried out by numerical simulation. It was found that the transformation of high vertical stresses in the entry floor underneath the filling wall and coal seam body into horizontal stresses starts the floor heave process. The vertical dilatancy of rocks under the roadway span and their subsequent unloading lead to the delamination of the floor strata and uplift of the entry contour. In this paper, the best pile installation scheme was found. It is a 2pile 5+2 scheme with the installation of two piles, each 2 m long. After that, it was shown that filling piles are more than 3.3 times cheaper than comparable analogs, and pile installation is less labor-intensive. The implementation of the proposed floor heave control method leads to a reduction in heaving by 2.47 times.
Mechanical model and numerical analysis of a method for local rock reinforcing to control the floor heave of miningaffected roadway in a coal mine
(IOP Publishing, 2022) Sakhno, I. G.; Sakhno, S. V.; Kamenets, V. I.; Сахно, І. Г.; Сахно, С. В.; Каменець, В. І.
A floor heave controlling method has been substantiated, based on the creation of locally reinforced zones of a special shape in roadway floor, which allows saving stability even with a low rocks friction ratio. The method is based on a mechanical model of the formation of an increasing strength spacer system in roadway floor. The numerical analysis of rock massif stress-strain state carried out by the finite element method, has made it possible to determine the mechanism of floor heave during rock reinforcing. The performed analysis of the simulation results has made it possible to determine the influence of the quality of rock reinforcing and the rock friction ratio value on the amount of heave in the mining-affected roadway. The effectiveness of the proposed method has been proven as a result of a comparative analysis.
Numerical simulation of the surface subsidence evolution caused by the flooding of the longwall goaf during excavation of thin coal seams
(IOP Publishing, 2023) Sakhno, I. G.; Sakhno, S. V.; Petrenko, A.; Barkova, O.; Kobylianskyi, B.; Сахно, І. Г.; Сахно, С. В.
Underground mining has a significant influence on ground movement, which induces serious environmental disturbances on land. Movements of the rock strata can be the cause of changes in the hydrogeological regimes of groundwater. As a result, the risk of flooding of the longwalls goaf increases. The specific phenomenon of the Ukrainian Donbas is the flooding of the underground roadway system at the result of the closure of the mines. Water saturation of rocks leads to a decrease in its strength. The result is repeated subsidence. The activation of the ground movement processes over the longwall goaf due to their flooding has not been studied enough. In this paper, for the geological conditions of thin coal seams typical for the Ukrainian Donbas, ground movement evolution caused by flooding of longwalls goaf was studied. Ansys code was used to analyze the evolution of surface displacement in different hydrogeological conditions. As a result of numerical simulation, it was found that full flooding of the longwall goaf leads to an increase in surface subsidence by 22.4%, while the length of the trough increase by 1.3%. Maximal inclination increases by 34.4%, and maximal curvature – by 74%. This contributes to a significant increase in hazards for surface infrastructure located on the edges of the subsidence trough. The control of the negative impact on surface infrastructure objects, water and agro-industrial objects can be ensured by a timely prediction of ground movement and the implementation of surface controlling methods to prevent critical surface deformations.
Numerical studies of floor heave control by the rock bolts reinforcement technology in retained gob-side gateroad
(EDP Sciences, 2024) Sakhno, I. G.; Sakhno, S. V.; Kamenets, V. I.; Cabana, E. C.; Сахно, І. Г.; Сахно, С. В.; Каменець, В. І.
The effectiveness of modified rock bolts reinforcement technology for floor heave control in gob-side entry retaining was studied in this paper. A finite-element numerical simulation was used to analyse stress-strain state of surrounding rocks before and after immediate floor reinforcement with six floor support schemes. It was found that after immediate floor reinforcement with rock bolts with diameter 32 mm and 96 mm, floor heave in retained gob-side gateroad reduces by 2.94 – 3.6 times respectively. The modification of rock bolt reinforcement scheme by the additional installation of piles in the entry corners was proposed. Piles installation significantly reduces the zone of horizontal and vertical post-peak strains in the gateroad floor. The best variant among compared ones is a floor support scheme with two corner piles, 1 m and 2 m long. With this scheme, floor heave decreases by 3.05 times. The comparison of the materials costs of the floor support schemes were performed. As a result, the most effective floor support scheme was proposed and prospects for the further progress of floor reinforcing technologies were outlined.
Numerical studies of floor heave mechanism and the effectiveness of grouting reinforcement of roadway in soft rock containing the mine water
(Elsevier, 2023) Sakhno, I. G.; Sakhno, S. V.; Сахно, І. Г.; Сахно, С. В.
A floor heave is a serious failure phenomenon in mining roadways, especially in soft rock containing the mine water. Considering the influences of moisture content on rock properties, a case study of the floor heave mechanism and grouting control technology was performed in this paper. The results of laboratory tests showed that with the increase of moisture content, the compressive strength and friction angle of mudstone linearly decreased, while the deformation modulus and cohesion tended to a negative exponential decrease approximately. A numerical simulation was used to study the stress and strain distributions of the surrounding rock. It was found that significant floor heave was caused plastic deformation of mudstone under high moisture content. In the case of large floor heave a “core” of vertical expansion is formed in the floor strata. This area of the surrounding rocks is mainly involved in the development of floor heave. Grouting reinforcement was proposed to control the floor heave. Five grouting schemes with different depth of reinforcement were studied. The numerical simulation demonstrated that after grouting reinforcement, plastic strain in the floor strata was reduced effectively. The minimum required grouting depth is determined by the allowable floor heave and moisture content. Ideally, the floor heaves could be reduced when the grouting depth is greater than the area where the “core” of vertical expansion appears.
Stress environment around head entries with pillarless gobside entry retaining through numerical simulation incorporating the two type of filling wall
(IOP Publishing, 2022) Sakhno, I. G.; Sakhno, S. V.; Kamenets, V. I.; Сахно, І. Г.; Сахно, С. В.; Каменець, В. І.
Longwall mining is the most productive system for underground extraction of coal. Many coal mines use a pillarless mining. Reserving a gateroad for the usage of next panel mining is a popular gob-side entry retaining. Thus, the conventional entry retaining method requires an installation of filling walls. The mechanical properties of filling materials largely determine the quality of job-side entry retaining. Stress field evolution study around head entries when main roof console length increase with two variants of filling wall. Ansys code was used to analyze the stress evolution law under different mining conditions. As a result of numerical simulation, it was found that in the case of gob-side entry retaining, the localization of maximum stresses in surrounding rock is determined by the length console of the main roof, which hanging on the border with the gob, and the filling walls deformation module. Potential location of roof cutting, stress gradient and extremum stress in the main roof define the stability of entries. Main roof console length and filling material parameters control can help to the formation of a stable structure around the entry to meet the requirements of the next working face.
Вплив затоплення вироблених просторів вугільних шахт на зсуви земної поверхні на прикладі шахти «Котляревська»
(Донецький державний технічний університет, 2022) Сахно, І. Г.; Сахно, С. В.; Петренко, А. В.; Баркова, О. О.; Sakhno, I. G.; Sakhno, S. V.; Petrenko, A. V.; Barkova, O. O.
Мета. Дослідження впливу затоплення вироблених просторів лав на активізацію зсувних процесів на підробленій земній поверхні.
Дослідження впливу параметрів технологічних схем очисних робіт на стійкість виробок при реалізації концепції «малих шахт»
(Донецький державний технічний університет, 2020) Сахно, С. В.; Бородіч, В. В.; Карлов, Є. К.; Sakhno, S. V.; Borodich, V. V.; Karlov, Ye. K.
Мета. Дослідження впливу параметрів технологічних схем виймання вугілля на напружено-деформований стан порід, що вміщують виробки, при реалізації концепції «малих шахт».
Дослідження локального зміцнення підошви виробки методом структурного моделювання
(Донецький гірничий інститут, 2020) Ісаєнков, О. О.; Сахно, І. Г.; Сахно, С. В.; Isaenkov, O. O.; Sakhno, I. G.; Sakhno, S. V.
Мета. Пошук і аналіз раціональних форм зміцнення порід підошви при їх блочно-дискретній структурі в умовах інтенсивного підняття в підземних гірничих виробках.
Спрямоване руйнування гірських порід невибуховими руйнуючими сумішами
(ТОВ "ТЕХНІЧНИЙ УНІВЕРСИТЕТ "МЕТІНВЕСТ ПОЛІТЕХНІКА", 2024) Сахно, І. Г.; Сахно, С. В.; Sakhno, I. G.; Sakhno, S. V.
Руйнування міцних гірських порід є одним з основних процесів у сучасній гірничодобувній промисловості. Найбільш поширеним способом руйнування скельних і навпівскельних гірських порід з міцністю по шкалі проф. Протодияконова більше 6 од. є вибуховий спосіб. Вибухове руйнування пов’язано з численними шкід-ливими впливами на гірський масив і довкілля. Окрім цього, ведення вибухових робіт пов’язано з ризиками пошкодження обладнання, приладів, комунікацій, які перебувають у зоні впливу вибухових робіт. Іноді вибу-хове руйнування не може бути використано через обмеження пило газового режиму або з інших питань безпеки. Екологічною альтернативою традиційним вибуховим методам руйнування міцних гірських порід є невибухові технології. Серед різних методів невибухового руйнування перспективним є метод, що базується на використанні невибухових руйнуючих сумішей. Невирішеним питанням невибухового руйнування гірських порід є спрямоване руйнування в заданих напрямках. Керування напрямком руйнування ведеться переважно за рахунок оптимізації схеми розташування шпурів. При цьому не враховуються природні дефекти, ослаблення і структурні неоднорідності гірських порід. Внаслідок цього спостерігається «ухил» тріщин від проєктного напрямку. Існують технічні рішення, що спрямовані на усунення наявних недоліків спрямованого невибухового руйнування, що ґрунтуються на використанні шпурових вставок і патронів. У статті розглянуто метод спрямованого руйнування гірських порід, який базується на створенні концентраторів розтягуючих напружень на поверхні шпура в необхідних місцях. Розглянуто вплив додаткового встановленого в шпур патрона невибухової руйнуючої суміші на поле напружень поблизу шпура. Запропоновано модифіковану конструкцію патрона невибухової руйнуючої суміші, що дає змогу керувати напрямком руйнування гірських порід під час коригування траєкторії руйнування, яка може бути непрямою лінією.