scholarly journals Research on Rapid Evaluation of Rock Mass Quality Based on Ultrasonic Borehole Imaging Technology and Fractal Method

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yuezheng Zhang ◽  
Hongguang Ji ◽  
Wenguang Li ◽  
Kuikui Hou
Keyword(s):  
Rock Mass ◽  
Evaluation Method ◽  
Fractal Theory ◽  
Box Dimension ◽  
Fractal Method ◽  
Imaging Technology ◽  
Rock Mass Quality ◽  
Hole Wall ◽  
Structural Surface ◽  
Borehole Imaging

The distribution of discontinuities in the deep stratigraphic rock mass is random and irregular, and the spatial distribution has statistical self-similarity, which can be analyzed by fractal theory. The borehole wall image obtained based on the ultrasonic borehole imaging technology can clearly reflect the rich structural surface information such as the inclination, density, and crack width of the structural surface in the rock mass. Due to its inherent fractal characteristics, the fractal box dimension of the hole wall image can be used to describe the complexity of the structural surface. In the study, the fractal box dimension of the hole wall image and the RQD value of the rock mass are compared, and it is found that there is a linear correlation between the two. Therefore, the rock quality can be evaluated according to the fractal box dimension value of the hole wall image. Finally, a rapid quantitative evaluation method for rock mass quality classification is established based on ultrasonic borehole imaging technology and fractal method.

Research of Coal Pores and Integrity Evaluation Method Based on Fractal Theory

2014 ◽  
Vol 670-671 ◽  
pp. 258-262 ◽  
Author(s):  
Ji Li ◽  
Xin Wu
Keyword(s):  
Fractal Dimension ◽  
Coal Sample ◽  
Evaluation Method ◽  
Structural Integrity ◽  
Gas Adsorption ◽  
Fractal Theory ◽  
Physical And Mechanical Properties ◽  
Box Dimension ◽  
Sem Images ◽  
Sem Image

Coal is a natural porous media, its porosity and structural integrity influenced the gas adsorption and desorption characteristics greatly, as well as physical and mechanical properties of coal. Scanning electron microscopy (SEM) is applied to acquire SEM image of four kinds of coal samples at different zoom levels, and the box dimension can be worked out based on the pore preprocessing of SEM images. Then, the numerical value of box dimension is used to describe the development degree of the four kinds of coal sample and four development degrees’ sequence. At last, the intrinsic relevance between fractal dimension and other parameters is analyzed through mathematic method. The results show as follows: coal sample has self-similarity characteristic; the fractal dimension is related to both the total number of pores and porosity degree; the data of the coal pore, analyzed through fractal dimension, are consistent with that through traditional method; what’s more, fractal dimension has more advantages in describing accuracy and simplicity.

scholarly journals Joint Investigation and 3D Visual Evaluation of Rock Mass Quality

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Haiping Yuan ◽  
Chenghao Chen ◽  
Yixian Wang ◽  
Hanbing Bian ◽  
Yan Liu
Keyword(s):  
Rock Mass ◽  
Quality Evaluation ◽  
Evaluation Method ◽  
Three Dimensional ◽  
Rock Mass Classification ◽  
National Standard ◽  
Ratio Method ◽  
Rock Mass Quality ◽  
Close Range ◽  
Mass Classification

In order to realize the high efficiency quality classification and three-dimensional visualization of engineering rock mass and to solve the technical difficulties of the traditional rock mass quality evaluation method such as high labor intensity, long process time consumption, many intervention processes such as scale measurement and manual calculation, and nonintuitive classification results, this paper puts forward a 3D visual rock mass quality evaluation method and system based on close-range photography, which optimizes the traditional rock mass quality evaluation method, makes the rock mass classification three-dimensional and visible, and realizes the estimation of unrevealed rock mass quality evaluation index. The research results show the following: (1) The method of storing joint information by close-range photography and extracting joint information by human-computer interaction improves the working efficiency and the process is safe and controllable compared with the traditional method of collecting fracture parameters. (2) Based on the statistical analysis of 97 groups of roadway survey data, the comprehensive statistical regression formula between BQ value of Chinese national standard and RMR value is given, and there is a good correlation between BQ value and RMR value of rock mass quality index. (3) Based on the power-inverse ratio method, the three-dimensional model of rock mass classification of the mine was established, and the cutting model obtained the current distribution diagram of rock mass quality grade, providing scientific reference for drilling, blasting, support, and other production design optimizations.

Evaluation Method of Urban Comprehensive Disaster-Carrying Capability Based on Fractal Theory

2011 ◽  
Vol 90-93 ◽  
pp. 3155-3160 ◽  
Author(s):  
Wei Wang ◽  
Jie Tian ◽  
Zhi Tao Wang ◽  
Xiao Dong Guo ◽  
Dong Hui Ma
Keyword(s):  
Evaluation Method ◽  
Fractal Theory ◽  
Fractal Dimensions ◽  
Assessment Method ◽  
Scientific Basis ◽  
Disaster Prevention ◽  
Actual Situation ◽  
Fractal Method ◽  
Characteristic Index ◽  
Fuzzy Assessment

In order to correctly evaluate urban comprehensive disaster-carrying capability and then to establish scientific basis for disaster prevention and reduction, a fractal method for urban comprehensive disaster-carrying capability is proposed on the basis of system principle which is that structure determines function. The fractal dimensions of 29 cities are calculated and analyzed. The results show that relative stronger, middling and weaker are respectively 13.79%, 65.52% and 20.69%, which are completely consistent with the actual situation. So the method can construct a characteristic index, and the main impact effects can be analyzed according to the result. Tested by examples together with the other two methods, i.e. the fuzzy assessment method and exponent method, the results verify effectively that this method is useful and feasible.

ethodical principles of designing the formation of rock mass quality for lump sorting scheelite-containing ores at the stage of mining

2019 ◽  
Vol 8 (29) ◽  
pp. 3-17
Author(s):  
V.A. Khakulov ◽  
◽  
V.A. Shapovalov ◽  
V.N. Ignatov ◽  
Zh.V. Karpova ◽  
...  
Keyword(s):  
Rock Mass ◽  
Rock Mass Quality

scholarly journals Weightage Effect during Back-Calculation of Rock-Mass Quality from the Installed Tunnel Support in Rock-Mass Rating and Tunneling Quality Index System

2019 ◽  
Vol 9 (10) ◽  
pp. 2065 ◽  
Author(s):  
Jonguk Kim ◽  
Hafeezur Rehman ◽  
Wahid Ali ◽  
Abdul Muntaqim Naji ◽  
Hankyu Yoo
Keyword(s):  
Rock Mass ◽  
Quality Index ◽  
Rock Bolt ◽  
Rock Mass Rating ◽  
Rock Mass Quality ◽  
Back Calculation ◽  
The Difference ◽  
Bolt Spacing ◽  
Q System ◽  
Selection Of

In extensively used empirical rock-mass classification systems, the rock-mass rating (RMR) and tunneling quality index (Q) system, rock-mass quality, and tunnel span are used for the selection of rock bolt length and spacing and shotcrete thickness. In both systems, the rock bolt spacing and shotcrete thickness selection are based on the same principle, which is used for the back-calculation of the rock-mass quality. For back-calculation, there is no criterion for the selection of rock-bolt-spacing-based rock-mass quality weightage and shotcrete thickness along with tunnel-span-based rock-mass quality weightage. To determine this weightage effect during the back-calculation, five weightage cases are selected, explained through example, and applied using published data. In the RMR system, the weightage effect is expressed in terms of the difference between the calculated and back-calculated rock-mass quality in the two versions of RMR. In the Q system, the weightage effect is presented in plots of stress reduction factor versus relative block size. The results show that the weightage effect during back-calculation not only depends on the difference in rock-bolt-spacing-based rock-mass quality and shotcrete along with tunnel-span-based rock-mass quality, but also on their corresponding values.

Study of Evaluation Method in Terms of Structural Planes Mechanical Characteristics in Engineering Rock Mass

2013 ◽  
Vol 353-356 ◽  
pp. 384-387 ◽  
Author(s):  
Mu Dan Guo ◽  
Fu Sheng Zhu ◽  
Shu Hong Wang ◽  
Xi Jiang Mu
Keyword(s):  
Rock Mass ◽  
Stability Analysis ◽  
Efficient Method ◽  
Weight Distribution ◽  
Evaluation Method ◽  
Mechanical Characteristics ◽  
Significant Issue ◽  
Analytic Hierarchy ◽  
Intensity Parameters ◽  
Hierarchy Process

Study of mechanical characteristics of structural planes has been significant issue in engineering rock mass stability analysis. The factors that affect the mechanical behavior of structural planes are so complicated that it is quite essential to take an efficient method to quantificationally analyze these factors. Based on the basic principals of analytic hierarchy process (AHP), a structural plane classification method-CSPC method is proposed. It can conduct weight distribution in terms of the complicated factors, assess the structural planes comprehensively and also forecast the planes intensity parameters semiquantitatively. The classification and forecast parameters of structural planes appropriately fit the cases in engineering. Furthermore, the method is easy to master for the engineers and the application can be of great prospect.

Study of the geometrical size effect of a fractured rock mass based on the modified blockiness evaluation method

2018 ◽  
Vol 11 (11) ◽  
Author(s):  
Qingfa Chen ◽  
Tingchang Yin ◽  
Wenjing Niu ◽  
Wenshi Zheng ◽  
Junguang Liu
Keyword(s):  
Rock Mass ◽  
Size Effect ◽  
Evaluation Method ◽  
Fractured Rock ◽  
Fractured Rock Mass ◽  
Geometrical Size

Evaluation Method for Rock Mass Structure Integrity Based on Borehole Multivariate Data

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Jinchao Wang ◽  
Hanhua Xu ◽  
Wei Chen ◽  
Chuanying Wang ◽  
Zengqiang Han
Keyword(s):  
Rock Mass ◽  
Evaluation Method ◽  
Multivariate Data ◽  
Rock Mass Structure
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