scholarly journals Analyzing mechanics of rock breaking under conditions of hydromechanical drilling

2021 ◽  
Vol 15 (3) ◽  
pp. 122-129
Author(s):  
Andrii Ihnatov
Keyword(s):  
Rock Mass ◽  
Physical Simulation ◽  
Breaking Load ◽  
Rock Breaking ◽  
Next Generation ◽  
Technological Parameters ◽  
Well Drilling ◽  
Dynamic Component ◽  
Stable Mode ◽  
Load Rate

Purpose is to substantiate design factors and technological parameters of next-generation facilities of hydromechanical drilling basing upon the determined features of interaction between breaking pellets and rock mass. Methods. The studies of directionality features and bottomhole processes for rock mass breaking have been carried out using the current analytical methods and laboratory experiments. Among other things, certain mathematical and physical simulation techniques, methods of theoretical processing and interpretation of the research results under SolidWorks, Statgraphics, and Маthсаd environments, and a number of relevant instruments and materials have been applied. Following their technological sequence, the well bottomhole rock-breaking processes were simulated using a special laboratory stand equipped with a control-and-measuring unit (inclusive of a flowmeter, manometer, tachometer, and coordinate spacer among other things). Findings. Application perspectiveness of the combined techniques for rock breaking has been proved. Structural designs of the next-generation facilities for well drilling have been proposed. The pellet-impact drilling features have been analyzed from the viewpoint of its significant dynamic component during the rock mass breaking. Nature of the effect of breaking load rate on the results of bottomhole deformation processes has been identified. Efficiency of the proposed scheme to improve pellet-impact drilling based upon maximum use of a well bottomhole deformed by pellets has been proved. Measures to increase technical and technological indicators of pellet drilling have been considered. Requirements for the conditions stabilizing operation of a collar of the pellet-impact device have been outlined. Further research tendencies have been specified. Originality. It has been determined that compliance with specific geometrical and hydromechanical ratios, corresponding to the stable mode of a well sinking, is the factor required for reliable operation of hydromechanical drilling facilities. Practical implications. The results of stand-based tests as well as analytical studies may become the foundations to develop efficient engineering decision for hydromechanical well drilling with high technical and economic indicators. The data, concerning bottomhole rock breaking processes, are the basic ones to work out rational standard parameters of well sinking processes.

scholarly journals Empirical regularities investigation of rock mass discharge by explosion on the free surface of a pit bench

2021 ◽  
Vol 249 ◽  
pp. 334-341
Author(s):  
Igor Alenichev ◽  
Ruslan Rakhmanov
Keyword(s):  
Rock Mass ◽  
Slope Angle ◽  
Rock Breaking ◽  
Key Factors ◽  
Technological Parameters ◽  
Factors Affecting ◽  
Geological Conditions ◽  
Empirical Regularities ◽  
Main Discharge ◽  
Mass Discharge

Minimizing the discharge of blasted rock mass into the developed space of the pit is a very relevant area for study, as it allows to increase the processability of work and reduce the cost of mining. The article presents the results of experimental industrial explosions, during which the study of this issue was conducted. The main purpose of the work was to establish the key factors affecting the volume of rock mass discharge to the pit haulage berm. During the analysis of the world experience of research on this topic, the key factors affecting the formation of collapse and discharge – natural and technological – are identified. The method of conducting experiments and collecting data for analyzing the influence of technological parameters of location, charging and initiation of wells on the volume of rock mass discharge is described. It is established that the main discharge to the pit haulage berm is formed by the volume of rock mass limited by the prism of the slope angle. With a sufficient rock mass displacement from the edge of the bench crest towards the center of the block, only the wells of the 1st and 2nd rows participate in the discharge formation. Empirical dependences of the total volume of rock mass discharge on the length of the block along the bench crest, the specific consumption of explosives, the size of a rock piece P50 and the rate of rock breaking are obtained. The obtained results can be used to design the parameters of the drilling and blasting operations (DBO), as well as to predict and evaluate the possible consequences of a mass explosion in similar mining and geological conditions.

scholarly journals The Mathematical Approach to the Identification of Trouble-Free Functioning of Mining Facilities

2020 ◽  
Vol 174 ◽  
pp. 02009
Author(s):  
Fares Abu-Abed
Keyword(s):  
High Tech ◽  
Mathematical Approach ◽  
Technological Parameters ◽  
Well Drilling ◽  
Emergency Situations ◽  
Technological Information ◽  
Drilling Equipment ◽  
Wide Range ◽  
Software And Hardware ◽  
Drilling Rigs

Modern drilling rigs are complexes of high-tech equipment operated in difficult climatic and technological conditions, characterized by sudden spasmodic changes in the process of drilling a well, which contributes to increased wear of drilling components and increases the likelihood of pre-emergency and emergency situations. Drilling equipment has a wide range of characteristics and technological parameters, the values of which are available during drilling due to the use of modern software and hardware systems for processing geological and technological information. In order to single out the most frequent pre-emergency situations in practice and to preliminarily determine the set of signs necessary for their recognition, a corresponding analysis of the complications arising during well drilling has been carried out.

scholarly journals The corresponding relationship between the change of goaf pressure and the key stratum breaking

2019 ◽  
Vol 16 (5) ◽  
pp. 913-925
Author(s):  
Jianlin Xie ◽  
Jialin Xu
Keyword(s):  
Rock Mass ◽  
Internal Pressure ◽  
Load Transfer ◽  
Physical Simulation ◽  
Field Measurements ◽  
Monitoring Methods ◽  
Key Stratum ◽  
Working Face ◽  
Actual Rock ◽  
Overlying Strata

Abstract Existing studies mostly focus on the stress change of coal in front of a goaf, but rarely conduct field monitoring on the internal pressure of a goaf, primarily due to the complex environment and other restrictive conditions of goafs. This paper first used physical simulation to monitor and analyze the internal pressure of goaf and found that goaf pressure presented a stepwise growth with the key stratum breaking. In addition, field measurements were conducted to monitor the goaf pressures of two different working faces. Goaf pressures both presented linear growth with the advance of the working face. According to comparative analysis, there were some differences between the two monitoring methods in terms of the corresponding relationship. This reflects that in the actual rock mass, after the breaking of a key stratum, the loads of the strata under its control are not transferred to the goaf instantaneously and load transfer characteristics are probably related to roof separation distribution characteristics of overlying strata, the bulking characteristics of caved rock mass, lateral stress limitation and other factors. The results of this study will offer some guidance for studies on the movement laws of overlying strata and the load transfer of overlying strata above goafs.

scholarly journals Liquid CO2 Phase-Transition Rock Fracturing: A Novel Technology for Safe Rock Excavation

2021 ◽  
Vol 12 (1) ◽  
pp. 68
Author(s):  
Haoyue Sui ◽  
Tianming Su ◽  
Ruilin Hu ◽  
Ke Yang ◽  
Yaxing Cheng
Keyword(s):  
Phase Transition ◽  
Rock Mass ◽  
Processing System ◽  
Field Tests ◽  
Fractal Dimensions ◽  
Dominant Frequency ◽  
Rock Breaking ◽  
Rock Breakage ◽  
Rock Fracturing ◽  
Liquid Co2

In order to determine the applicability of liquid CO2 phase-transition fracturing technology in rock mass excavations, the principles of CO2 phase-transition fracturing were analyzed, and field tests of liquid CO2 phase-transition fracturing were performed. An “Unmanned Aerial Vehicle (UAV) camera shooting + Microstructure Image Processing System (MIPS) analyzing” method was used to acquire the rock mass characteristics. Further, the Hilbert–Huang Transform (HHT) energy analysis principle was adopted to analyze the characteristics of fracturing vibration waves. The experimental results showed that during the process of fracturing, there were both dynamic actions of rock breakage due to excitation stress wave impacts, and quasi-static actions of rock breakage caused by gasification expansion wedges. In semi-infinite spaces, rock-breakage zones can mainly be divided into crushing zones, fracture zones, and vibration zones. At the same time, under ideal fracturing effects and large volumes, the fracturing granularity will be in accordance with the fractal laws. For example, the larger the fractal dimensions, the higher the proportion of small fragments, and vice versa. Moreover, the vibration waves of the liquid CO2 phase-transition fracturing have short durations, fast attenuation, and fewer high-frequency components. The dominant frequency band of energy will range between 0 and 20 Hz. The liquid CO2 phase-transition fracturing technology has been observed to overcome the shortcomings of traditional explosive blasting methods and can be applied to a variety of rock types. It is a safe and efficient method for rock-breaking excavations; therefore, the above technology effectively provides a new method for the follow-up of similar engineering practices.

scholarly journals Dynamic Rock-Breaking Process of TBM Disc Cutters and Response Mechanism of Rock Mass Based on Discrete Element

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Qinglong Zhang ◽  
Yanwen Zhu ◽  
Canxun Du ◽  
Sanlin Du ◽  
Kun Shao ◽  
...  
Keyword(s):  
Rock Mass ◽  
Failure Modes ◽  
Confining Pressure ◽  
Rock Breaking ◽  
Disc Cutter ◽  
Repeated Loading ◽  
Response Mechanism ◽  
Disc Cutters ◽  
Crack Penetration ◽  
Cutter Spacing

Rock-breaking efficiency of full-face rock tunnel boring machine (TBM) is closely related to the performance of the disc cutter and the characteristics of the rock mass. In the point of view of mesomechanics, the particle flow code (PFC) is used to establish a numerical model of the rock mass and the disc cutter, and the process of TBM disc cutter intrusion into the rock mass is analyzed. The dynamic response mechanism and crack evolution process of the rock mass under the action of the disc cutter are studied on the basis of micromechanics, and the relationship between the rock mass crack, penetration, and cutting force during the intrusion of the disc cutter is revealed. The sensitivity analysis is carried out on the confining pressure conditions and the influence parameters of the disc cutter spacing. The results show that the rock breaking by disc cutter undergoes the transformation characteristics of compaction, shearing, and tension failure modes, and the failure process of the rock mass is the joint action of tension and shear. In the whole process of rock breaking, the disc cutter has the phenomenon of repeated loading-unloading alternation and leaping rock breaking; after the penetration of the disc cutter reached 9.0 mm, penetration creaks begin to appear on the surface of the rock mass; the penetration was obviously reduced with the increase of confining pressure, and it is mainly the penetration cracks on the surface; after the disc cutter spacing reaches 100.0 mm, there is no penetration crack between the two disc cutters. The research conclusion can provide a reference for the disc cutter optimization design.

scholarly journals Modeling of influence of stresses on indicators of resistance of mining rocks to mechanical destruction

2019 ◽  
Vol 109 ◽  
pp. 00104
Author(s):  
Serhii Tynyna ◽  
Ihor Chobotko ◽  
Liliya Frolova ◽  
Tetyana Butyrina
Keyword(s):  
Rock Mass ◽  
Coordinate System ◽  
Stress Tensor ◽  
Rock Breaking ◽  
Infinite Cylinder ◽  
Mechanical Destruction ◽  
Cylindrical Coordinate ◽  
The Face ◽  
Improper Integrals ◽  
Analytical Expressions

The article deals with the problem of determining the expression for the components of the stress tensor of a rock mass that is exposed to rock-breaking tools. In solving this problem, the natural tension of the rocks and the stresses arising ahead, in the plane and on the boundary of the face of the cylindrical excavation were taken into account. Formulation presented in the form of a semi-infinite cylinder whose axis coincides with the axis ̅Z of the coordinate system. The solution is obtained in a cylindrical coordinate system in the form of analytical expressions, which is carried out by numerical integration of improper integrals.

Physical Simulation Study on Transverse Effect of Bolted Discontinuous Rock Mass

2014 ◽  
Vol 1008-1009 ◽  
pp. 1292-1296
Author(s):  
Ying Xuan Jia ◽  
Hong Wei Song ◽  
Gui Zhang ◽  
Xing Kuang
Keyword(s):  
Rock Mass ◽  
3D Model ◽  
Physical Simulation ◽  
Shear Loading ◽  
New Findings ◽  
Bolt Stress ◽  
Negative Effect ◽  
Transverse Effect ◽  
Discontinuous Rock ◽  
Bolt Diameter

In order to illustrate the mechanism of supporting, maintain the safety and keep the stable of underground projects, it is of great significance to study the transverse effect of bolted discontinuous rock mass. With a 3D model and corresponding physical simulation, analyzing the testing results of the bolt stress, rock stress and displacement discovers some new findings. Besides its reinforcing effect to the rock mass, the bolt has a negative effect on the discontinuous rock mass by its so-called ‘railway effect’ under shear loading. The finding of this bolt function will help to further understand of bolting mechanism and it is very important to raise the safety of bolt supporting design. Furthermore the effect grade is a positive correlativity with the bolt diameter, and the shear displacement is one of its necessary conditions.

scholarly journals Investigation Structure and Properties of Wire From The Alloy of Al-rem System Obtained With The Application of Casting in The Electromagnetic Mold, Combined Rolling-Extruding and Drawing

2021 ◽  
Author(s):  
Sergey Borisovich Sidelnikov ◽  
Denis Sergeevich Voroshilov ◽  
Mikhail Mikhaylovich Motkov ◽  
Viktor Nikolaevich Timofeev ◽  
Igor Lazarevich Konstantinov ◽  
...  
Keyword(s):  
Rare Earth ◽  
Relative Elongation ◽  
Experimental Studies ◽  
Earth Metal ◽  
Experimental Alloy ◽  
Structure And Properties ◽  
Technological Parameters ◽  
Laboratory Unit ◽  
Stable Mode ◽  
Cold Worked

Abstract The paper presents the results of studies of the structure and properties of a wire with a diameter of 0.5 mm from an alloy of the Al-REM system with a rare-earth metal content of 7-9%. Wire obtained as a result of the implementation of the technology of its manufacture using the methods of casting into an electromagnetic mold (EMM), continuous extruding and drawing.The rheological properties of the metal of continuously cast round billets from the experimental alloy obtained using an electromagnetic mold are determined. The modeling and analytical assessment of the possibility of carrying out the process of combined rolling-extruding (CRE) of such billets in a closed box-type roll groove of a continuous extruding unit are carried out. The features of metal shaping have been studied. The temperature-speed and technological parameters was found at which the CRE process can be carried out in a stable mode of operation. Data have been obtained for the forces acting on the die and rolls and the moments on the rolls during rolling-extruding.The results of experimental studies of the process of obtaining longish deformed semi-finished products from an experimental alloy on the laboratory unit CRE-200 and the pilot plant unit CRE-400 are presented. The structure of the metal has been studied; data on the ultimate tensile strength, yield strength, relative elongation, and electrical resistivity of hot-extruded rods and wires in cold-worked and annealed states have been obtained.It was found that the proposed processing modes make it possible to obtain by the method of combined rolling-extruding rods with a diameter of 9 mm in industrial conditions from longish billets with a diameter of 18 mm, cast by means of EMM. Wire in a cold-worked and annealed state with a diameter of 0.5 obtained by drawing from the rods with a diameter of 9 mm from an experimental alloy of the Al-REM system containing 7-9 rare earth metals with the required physical and mechanical properties.

scholarly journals Geological and mining-engineering peculiarities of implementation of hydromechanical drilling principles

2021 ◽  
pp. 11-18
Author(s):  
A.O. Ihnatov ◽  
Ye.A. Koroviaka ◽  
Jan Pinka ◽  
V.O. Rastsvietaiev ◽  
O. O. Dmytruk
Keyword(s):  
Technological Development ◽  
Control Unit ◽  
Rock Breaking ◽  
Operating Parameters ◽  
Drilling Process ◽  
Technological Parameters ◽  
Technical Performance ◽  
Starting Point ◽  
Mathematical And Physical Modeling ◽  
Model Preparation

Purpose. Substantiation of the design solutions in separate units of the modernized hydromechanical devices and specification of rational technological modes of their operation in specific geological and technical conditions. Proposals on construction of wells by development and introduction of progressive methods and techniques. Methodology. Analysis of the peculiarities of the modernized hydromechanical drilling devices in terms of rock breaking is performed using modern methods of analytical analysis and experimental research, i.e. by using mathematical and physical modeling; method of modeling and processing of research results in the SolidWorks medium and others; control and measuring tools and materials. The process of solving the problems of optimal planning of the experiment was divided into four stages: development of a planned model; preparation of the necessary initial data; calculation of the model; obtaining and processing of the results. The well rock-breaking processes were modeled on a special-purpose laboratory stand equipped with a measuring and control unit (flow meter, manometer, tachometer, and coordinate spacer). Findings. The main ways to improve well hydromechanical technologies have been identified. The fundamental principles have been formulated concerning the process of design of such equipment schemes that will combine the most productive and efficient methods of the rock mass operations. A number of factors characteristic of the implementation of well hydromechanical technologies, have been identified, i.e.: rational range of physical properties of rocks according to which proper technical and technological characteristics of the devices are selected; structural use of mechanical rock-breaking organs of the devices; and operating parameters of the drilling process. It has been proved that the developed design schemes of hydromechanical drilling devices, in terms of their optimal technical performance and technological development, can be recommended for their use in the appropriate geological and technical conditions, where the implementation of other methods is inexpedient or limited. Originality. Formation of the peripheral part of the bottomhole is a subordinate factor determined by the device design; effective profiling is possible only due to the introduction of additional components into the hydromechanical drilling devices, which makes it possible to use certain technological methods. Practical value. The obtained results of laboratory and analytical studies are basic to design operating parameters of the well deepening processes by using the hydromechanical devices. Data from the study on bottomhole working processes of hydromechanical technologies are the starting point for the substantiation of design and technological parameters of modernized pellet impact devices.

Sign in / Sign up

Export Citation Format

Share Document