scholarly journals New theory for the rock mass destruction by blasting

2021 ◽  
Vol 15 (2) ◽  
pp. 111-123
Author(s):  
Maksym Kononenko ◽  
Oleh Khomenko
Keyword(s):  
Mathematical Modeling ◽  
Rock Mass ◽  
Rock Pressure ◽  
Solid Medium ◽  
Fractured Rock ◽  
Physical And Mechanical Properties ◽  
Mass Destruction ◽  
Energy Characteristics ◽  
Calculation Results ◽  
Pressure Impact

Purpose. To develop a new theory for the rocks destruction by blasting using a description of the formation processes of zones with various mass state around the charging cavity. Methods. The new theory for the rock mass destruction by blasting has been developed based on the use of the well-known elasticity theory laws and the main provisions of the quasi-static-wave hypothesis about the mechanism of a solid medium destruction under the blasting action. The models of zones of crumpling, intensive fragmentation and fracturing that arise around the charging cavity in the rock mass during its blasting destruction, depending on the physical and mechanical pro-perties of the rock mass, the energy characteristics of explosives and the rock pressure impact, have been developed using the technique of mathematical modeling. Findings. Based on the mathematical modeling results of the blasting action in a solid medium, the mathematical models have been developed of the zones of crumpling, intensive fragmentation and fracturing, which are formed around the char-ging cavity in a monolithic or fractured rock mass. Originality. The rock mass destruction by blasting is realized according to the stepwise patterns of forming the zones of crumpling, intensive fragmentation and fracturing, which takes into account the physical and mechanical properties of the medium, the energy characteristics of explosives and the rock pressure impact. Practical implications. When using the calculation results in the mathematical modeling the radii of the zones of crumpling, intensive fragmentation and fracturing in the rock mass around the charging cavity, it is possible to determine the rational distance between the blasthole charges in the blasting chart, as well as to calculate the line of least resistance for designing huge blasts.

The Calculation of Grouting Diffusion Radius on Based Bingham Fluid for Chunnel That Passes through Fractured Rock Mass

2012 ◽  
Vol 256-259 ◽  
pp. 1280-1286
Author(s):  
Lei Wang ◽  
Tao Li
Keyword(s):  
Rock Mass ◽  
Calculation Result ◽  
Fractured Rock ◽  
Bingham Fluid ◽  
Theoretical Formula ◽  
Fractured Rock Mass ◽  
Real Situation ◽  
Grouting Pressure ◽  
Calculation Results ◽  
Design Requirements

To conduct pro-grouting design and make the prediction of the result of grouting about the chunnel that passes through fractured rock mass, the essay adopts following theoretical formula to calculate the fractured rock mass grouting diffusion radius: Wittke and Wallner Formula、Lombadi Formula and Huang Chunhua Formula. Finally through the analysis of calculation results can conclude: (I) The diffusion radius of the slurry can meet the design requirements under the condition of 3-4 Mpa designed grouting pressure、5 cm grouting holes’ radius and 1800-3600s grouting time. (II) The calculation result of Huang Chunhua Formula is almost the same as Wittke and Wallner Formula and Lombadi Formula, but the margin of grouting diffusion radius’ change as grouting time and grouting pressure growing are different, it’s more close to the real situation.(III) The calculation of these theoretical formula only consider the breadth of fractured rock without considering the variation of its thickness and direction. So all of the calculation results of these formula are generally bigger than the standard.

scholarly journals SPATIAL VARIABILITY OF PHYSICAL AND MECHANICAL PROPERTIES OF ROCK MASS IN CENTRAL KAZAKHSTAN

2020 ◽  
Vol 17 (34) ◽  
pp. 718-726
Author(s):  
Auez E ABETOV ◽  
Abylay N UZBEKOV ◽  
Nicolay N GRIB ◽  
Andrey E MELNIKOV ◽  
Yury A MALININ
Keyword(s):  
Mathematical Modeling ◽  
Mechanical Properties ◽  
Rock Mass ◽  
Spatial Variability ◽  
Three Dimensional ◽  
Single Layer ◽  
Physical And Mechanical Properties ◽  
Linear Interpolation ◽  
Drilling Process ◽  
Drilling Rig

The efficiency and quality of drilling and blasting operations in the development of mineral deposits largely depend on the variability of the properties of the rock mass. With a detailed study of various geological objectsmineral deposits or structural elements of the earth’s crust of any order, up to a single layer or block, it is possible to create three-dimensional digital models. The article considers the possibility of spatial variability of rock mass properties in Central Kazakhstan by means of mathematical modeling using data from the drilling process control file of the Aquila system of a DH-M drilling rig. To assess the structure and condition of the rock mass, it was constructed two-dimensional sections digital model, which shows the spatial variability of physical and mechanical properties. A pseudolinear approximation between the file vectors is chosen as a method for constructing twodimensional sections. The application of the mathematical method of pseudo-linear interpolation is shown, which allows with a sufficient degree of reliability to evaluate the physical and mechanical properties (PMP) of the rocks in the inter-well and inter-interval space of the rock mass. Based on the results of the study, the software was developed that provides an operational and effective assessment of the physical and mechanical properties of the rock mass with the visualization of the result. The developed approach and software can be used to improve the efficiency of drilling and blasting operations of existing mining enterprises, as well as in the implementation of scientific and industrial research on mathematical modeling of state of the rock mass.

scholarly journals Multi-Source Information Monitoring Test of Fractured Rock Mass Destruction Characteristics and Sensitivity Analysis of Precursor Phenomena

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 538
Author(s):  
Qinghe Zhang ◽  
Tianle Zheng ◽  
Xiaorui Wang ◽  
Zhiyuan Fang
Keyword(s):  
Temperature Field ◽  
Rock Mass ◽  
Standard Deviation ◽  
Early Warning ◽  
Strain Field ◽  
Fractured Rock ◽  
Monitoring Methods ◽  
Mass Destruction ◽  
Fractured Rock Mass ◽  
Monitoring Information

The accuracy of the monitoring information is particularly important for exploring fractured rock mass deformation and failure mechanisms and precursor characteristics. Appropriate monitoring methods can not only timely and effectively reflect the failure laws of fractured rock masses but also play an early warning role. To explore more reasonable monitoring methods, uniaxial compression experiments and real-time non-destructive monitoring on prefabricated fractured rock specimens through DIC, AE, and IRT were conducted; the strain field, temperature field, ringing frequency, standard deviation, etc. were analyzed; and correlation between the three methods in the information of audience was explored. The results show the following. (1) The failure evolution process of fractured rock mass can be divided into four stages. DIC can detect the initiation and propagation of cracks near the fractures of the specimen at the earliest stages. (2) The order of occurrence of precursor phenomena in multi-source monitoring information is different, which is vertical strain field > shear strain field > horizontal strain field > temperature field > ringing times. (3) The dispersion degree of standard deviation of each field is obviously different; the infrared temperature field is greater, but the strain field and temperature field show the same trend. (4) There are obvious precursors before the specimen is on the verge of instability; acoustic emission detected two consecutive increases in the cumulative number of ringing before destruction, which means the most obvious precursors. The research results can provide a theoretical basis for the precursory information capture and damage early warning of the fractured rock mass destruction process.

scholarly journals The method for determining the parameters of the diagrams of a truncated-wedge destruction of cylindrical samples of rocks

2021 ◽  
pp. 47-52
Author(s):  
L. M. Vasyliev ◽  
D. L. Vasyliev ◽  
O. Ye. Nazarov ◽  
M. G. Malich ◽  
V. O. Katan
Keyword(s):  
Mathematical Modeling ◽  
Rock Mass ◽  
Residual Strength ◽  
Strength Criterion ◽  
Contact Friction ◽  
Calculation Algorithm ◽  
Limiting State ◽  
Rock Samples ◽  
Calculation Results ◽  
Experimental Values

Purpose. Development of an analytical method for calculating the parameters of complete diagrams longitudinal tension deformation for the truncated-wedge shape of destruction of cylindrical rock samples to control the stress-strain state of the rock mass and effective destruction of these materials during disintegration. Methodology. Analytically, by developing a mathematical model of the fracture process of cylindrical rock samples with their truncated-wedge form of crack development, an algorithm is created for calculating the full deformation diagram from the acting tension using the experimental values of four indicators of material properties the shear resistance limit, internal and external friction coefficients and elastic modulus. The method is based on the improved Coulomb strength criterion, supplemented by the parameters of contact friction and allowing one, using the theory of slip lines, to calculate the limiting state of the material at the tip of cracks developing from the edges of the sample of the correct geometry, taking into account the release of part of the material from the load and compliance with Hookes law deformation of the sample bearing area and the specific force on it. Findings. The method of mathematical modeling makes it possible to determine the ultimate strength and residual strength of cylindrical rock samples using four property indicators that can be experimentally established by simple methods. Originality. For the first time, analytical modeling of the process of destruction of cylindrical rock samples with their truncated-wedge form of destruction was carried out, taking into account the internal contact friction depending on the properties of the rock material and external contact friction. Practical value. The proposed method of mathematical modeling and the calculation algorithm make it possible to determine the limit and residual strength of rock samples using four property indicators, which can be established experimentally by simple methods under laboratory conditions of enterprises of the mining and metallurgical complex. The calculation results can be quickly used to control the state of the rock mass and effective destruction upon disintegration.

MODELING THE HYDRAULIC CHARACTERISTICS OF DRAIN VALVE AND BURST FITTING OF AN AIRCRAFT ACCIDENT-RESISTANT FUEL SYSTEM

2020 ◽  
Vol 7 (3) ◽  
pp. 37-44
Author(s):  
KONSTANTIN NAPREENKO ◽  
◽  
ROMAN SAVELEV ◽  
ALEKSEY TROFIMOV ◽  
ANNA LAMTYUGINA ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Hydraulic Resistance ◽  
Hydraulic Calculation ◽  
Fuel System ◽  
Hydraulic Characteristics ◽  
System A ◽  
Ansys Cfx ◽  
Calculation Results ◽  
Scale Experiment ◽  
Aircraft Accident

The article discusses methods for determining the hydraulic resistance of units of an accident-resistant fuel system. A detailed description of the need to create such fuel systems for modern helicopters is given. The development of such systems today is impossible without the use of the method of mathematical modeling, which allows to qualitatively solve problems arising in the design process. To obtain accurate research results, it is necessary to have a complete description of all elements and assemblies of the system. Methods for determining the hydraulic characteristics of AFS elements using the drag coefficient, reference literature and CFD codes are considered. As the investigated AFS units, a drain valve and burst fitting were studied in the article. A hydraulic calculation of these AFS elements ware performed, the simulation results are presented in the ANSYS CFX software package. Also as the calculation results of bursting fitting, the pressure distribution fields of full and static pressure, velocity and streamlines are also shown. An experimental setup for validating the results obtained using the mathematical modeling method is considered, as well as a methodology for conducting a full-scale experiment to determine the hydraulic resistance of the unit. Materials have been prepared for inclusion in a one-dimensional mathematical model of an accident-resistant fuel system.

scholarly journals Fracture System and Rock-Mass Characterization by Borehole Camera Surveying: Application in Dimension Stone Investigations in Geologically Complex Structures

2021 ◽  
Vol 11 (2) ◽  
pp. 764
Author(s):  
Ivica Pavičić ◽  
Ivo Galić ◽  
Mišo Kucelj ◽  
Ivan Dragičević
Keyword(s):  
Rock Mass ◽  
Fractured Rock ◽  
Low Cost ◽  
Fracture Pattern ◽  
Dimension Stone ◽  
Rock Mass Characterization ◽  
Size And Shape ◽  
Distribution Parameters ◽  
Borehole Camera ◽  
Fracture Distribution

The successful exploration of dimension stone mainly depends on the quality, size, and shape of extractable blocks of dimension stone. The investigated area is in the Pelješac Peninsula (Croatia), in the External Dinarides orogeny, built from thick carbonate succession, characterized by relatively small deposits of high-quality dimension stone. These conditions demand challenging geological investigations in the “pre-quarry” phase to find optimal quarry location. The size and shape of dimension stone blocks are mainly controlled by fracture pattern systems. In the rugged, covered terrains, it is very hard to obtain a satisfactory amount of fracture data from the surface, so it is necessary to collect them from the underground. Borehole camera technology can visualize the inner part of the rock mass and measure the fracture characteristics. The main conclusions are as follows: (1) the digital borehole camera technology provides a quick, effective, and low-cost geological survey of fractured rock mass; (2) statistical fracture distribution parameters, P10, fracture spacing, Volumetric Joint Count (Jv) based on borehole wall survey can reflect the integrity of rock mass, providing a solid decision-making base for further investment plans and dimension stone excavation method.

Sign in / Sign up

Export Citation Format

Share Document