Method and system for analyzing morphological characteristics of three-dimensional crack surface of rock blasting material

Abstract

The invention relates to the technical field of blasting, in particular to a morphological characteristic analysis method and system for a three-dimensional crack surface of a rock blasting material. The morphological characteristic analysis method for the three-dimensional crack surface of the rock blasting material comprises the following steps: acquiring three-dimensional crack surface characteristic information of a transparent brittle rock material under the action of a blasting load to be researched; analyzing a crack three-dimensional expansion rule and morphological characteristics by utilizing the three-dimensional crack surface characteristic information; constructing a three-dimensional crack surface numerical model based on the analysis result of the crack three-dimensional expansion rule and the morphological characteristics; and analyzing the morphological characteristics of the three-dimensional crack surface according to the three-dimensional crack surface numerical model. The analysis method provided by the invention can be used for underground engineering facility construction, and the morphological characteristics of the three-dimensional crack surface are analyzed in time to select a proper blasting mode, so that the safety and long-term stability of the underground engineering facility construction are improved.

Description

Technical Field

[0001] The invention relates to the field of blasting technology, and in particular to a method and system for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials. Background Art

[0002] Rock blasting damage cracks are one of the main factors restricting the effect of engineering blasting and are also the focus of research by scientific researchers. During the construction of underground engineering facilities, when blasting and excavating the rock mass, deep rock mass will produce cracks under the coupling of the original rock stress field and the explosion stress field. This crack not only reduces the blasting effect, but also seriously affects the safe construction and long-term stability of deep underground engineering. Under the action of blasting load, the explosion energy is released rapidly, and the dynamic crushing time around the blasthole is extremely short, making it almost difficult to observe the expansion process of each crack.

[0003] In the existing technology, one technology adopts digital laser dynamic caustic experiment, takes PMMA as model material, and explores the influence of micro-difference delay on dynamic intensity factor of crack and crack propagation direction under micro-difference blasting load; another technology adopts digital laser dynamic caustic experiment and ABAQUS numerical analysis method, explores the dynamic propagation law of crack at the bottom of single and explosive column under blasting load and the distribution law of stress field around blasting hole; another technology adopts ABAQUS numerical analysis method, takes PMMA as model material, and explores the behavior of crack surface produced by dynamic fracture of brittle material under blasting load.

[0004] The above prior art only introduces the crack propagation law under the action of single-stage blasting, but does not study the crack propagation law under the action of multi-stage blasting, nor does it conduct a detailed study on the morphological characteristics of the crack surface. At present, the research on the three-dimensional crack surface morphological characteristics of transparent brittle rock blasting materials is relatively poor. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a method and system for analyzing the morphological characteristics of the three-dimensional crack surface of rock blasting materials. On the one hand, the method for analyzing the morphological characteristics of the three-dimensional crack surface of rock blasting materials includes the following steps: obtaining the three-dimensional crack surface characteristic information of the transparent brittle rock material under the blasting load to be studied; analyzing the three-dimensional crack expansion law and morphological characteristics using the three-dimensional crack surface characteristic information; constructing a three-dimensional crack surface numerical model based on the analysis results of the three-dimensional crack expansion law and morphological characteristics; and analyzing the morphological characteristics of the three-dimensional crack surface according to the three-dimensional crack surface numerical model. The invention adopts PMMA material as an experimental model, wherein DDNP explosives provide blasting energy to the experimental model, and a three-dimensional morphology of a crack surface after blasting is displayed in combination with a three-dimensional scanning device, and the three-dimensional crack distribution law and morphological characteristics of a transparent rock material under a multi-stage initiation condition are analyzed by means of the three-dimensional morphology, wherein the multi-stage initiation ensures that the crack is stimulated and expanded for multiple times, thereby better studying the crack expansion law; further, a three-dimensional numerical model is established to simulate the stress field evolution law in the crack expansion process of the rock under the action of a slotting blasting load, thereby more easily displaying the morphological characteristics of the three-dimensional crack of the rock, and facilitating analysis and research; the analysis method can be used for underground engineering facility construction, and a suitable blasting method can be selected by timely analyzing the morphological characteristics of the three-dimensional crack surface, thereby improving the safety and long-term stability of the underground engineering facility construction.

[0006] Optionally, the acquisition of three-dimensional crack surface characteristic information of the transparent brittle rock material under the blasting load to be studied includes: acquiring image information of the three-dimensional crack expansion evolution process; acquiring three-dimensional crack surface data point information. The present invention acquires the image information and data point information of the three-dimensional crack surface expansion evolution process under blasting load conditions through a three-dimensional scanner. The image information clearly and intuitively reflects the expansion evolution process of the three-dimensional crack under blasting conditions in different time periods, which is conducive to comparative analysis and research of crack expansion morphology under conditions in different time periods; the data point information is processed by Geomagic studio and MATLAB data software to ensure that the morphological characteristics of the three-dimensional crack surface can be analyzed by simulating and restoring the three-dimensional morphology of the real crack surface.

[0007] Optionally, the use of the three-dimensional crack surface feature information to analyze the three-dimensional crack expansion law and morphological characteristics includes: using the three-dimensional crack surface feature information to analyze the three-dimensional crack expansion law and morphological characteristics under multi-stage detonation. The present invention sets the delay time through a sequential detonation device, detonates the blasthole at different time periods, and observes the expansion law and morphological characteristics of the crack under multiple excitation conditions. It can not only observe the morphological characteristics of the primary crack, but also the expansion and evolution process of the secondary crack, which is convenient for analyzing the formation characteristics of the three-dimensional crack surface.

[0008] Optionally, the construction of a three-dimensional crack surface numerical model based on the analysis results of the three-dimensional crack expansion law and morphological characteristics includes: constructing a three-dimensional model of a crack surface morphology chromatogram based on the analysis results of the three-dimensional crack expansion law and morphological characteristics. The present invention uses a three-dimensional scanning device to scan the point cloud data of the blasting crack surface, and uses Geomagic studio software and MATLAB software to process and construct a three-dimensional crack surface morphology chromatogram, and the three-dimensional crack surface morphology chromatogram uses different colors to reflect the flatness of the crack surface, thereby more vividly describing the morphological characteristics of the three-dimensional crack surface in different regions.

[0009] Optionally, the morphological feature analysis of the three-dimensional crack surface according to the three-dimensional crack surface numerical model includes: analyzing the height difference of the three-dimensional crack surface according to the three-dimensional crack surface numerical model; analyzing the flatness of the three-dimensional crack surface according to the three-dimensional crack surface numerical model; analyzing the skewness of the three-dimensional crack surface according to the three-dimensional crack surface numerical model; analyzing the kurtosis of the three-dimensional crack surface according to the three-dimensional crack surface numerical model. The present invention realizes the analysis of the morphological features of the three-dimensional crack surface based on the analysis of the height difference, flatness, skewness, and kurtosis of the three-dimensional crack surface. The analysis method extracts the height value and variance value of the micro-convex body on the three-dimensional crack surface, and introduces two characteristic parameters of skewness and kurtosis. The height value, variance value, skewness, and kurtosis are used to quantitatively analyze the flatness and distribution uniformity of the three-dimensional crack, ensuring that the morphological features of the three-dimensional crack surface can be analyzed in a multi-dimensional subtle manner, thereby realizing the visualization and comprehensiveness of the morphological feature analysis of the three-dimensional crack surface.

[0010] Optionally, analyzing the height difference of the three-dimensional crack surface according to the three-dimensional crack surface numerical model includes: performing height difference analysis on the three-dimensional crack surface according to a calculation result of a three-dimensional crack surface height difference expression, and the height difference expression is as follows: ; in, It is expressed as the relative height value of any point on the crack surface. It is expressed as the absolute height value of any point on the crack surface. n Represents a positive integer. The present invention constructs a height difference expression based on the three-dimensional morphology chromatogram of the crack surface. The calculation result of the height difference expression is used to analyze the relative height value of any point on the three-dimensional crack surface to determine whether there is an extreme high point. The advantage is that the expansion of a certain point on the crack surface can be judged through one calculation result, thereby realizing a visual analysis of the damage risk of the three-dimensional crack surface.

[0011] Optionally, the analyzing the flatness of the three-dimensional crack surface according to the three-dimensional crack surface numerical model includes: performing a flatness analysis on the three-dimensional crack surface according to a calculation result of a three-dimensional crack surface flatness expression, wherein the flatness expression includes an expression for an average value of the three-dimensional crack surface height and an expression for a variance value of the height of micro-convexities on the three-dimensional crack surface, which are respectively as follows: ; ; in, Expressed as the average value of all heights of the three-dimensional crack surface, represents the height variance of the micro-convex body on the three-dimensional crack surface, It is expressed as the relative height value of any point on the crack surface. n Represents a positive integer. The present invention extracts the height value and variance value of the micro-convex body on the three-dimensional crack surface to judge the discreteness of the point cloud data, whether the crack surface is obviously undulating and whether it is easy to have a large fault, so as to quantitatively describe the change law of the three-dimensional morphology of the crack surface; the advantage is that by comprehensively processing the heights of multiple data points, only two parameters such as the height value and variance value of the micro-convex body on the three-dimensional crack surface are obtained and analyzed, thereby realizing the simplification and visualization of the analysis method.

[0012] Optionally, analyzing the skewness of the three-dimensional crack surface according to the three-dimensional crack surface numerical model includes: performing skewness analysis on the three-dimensional crack surface according to a calculation result of a three-dimensional crack surface skewness expression, and the three-dimensional crack surface skewness expression is as follows: ; in, It is expressed as skewness, which is used to describe the direction and degree of skewness of data distribution, and is also used to describe the asymmetry of the high-speed frequency distribution of point clouds on the crack surface. Expressed as the mean height of the point cloud, σ Expressed as the standard deviation of point cloud height, n Represents a positive integer. In order to analyze the overall morphology of the crack surface more carefully and comprehensively, the present invention introduces a characteristic parameter of skewness, which is defined by the mean value of the point cloud height, the standard deviation of the point cloud height and the number of regional data points. Only a skewness parameter can be used to determine whether the point cloud height distribution of the crack surface is symmetrical.

[0013] Optionally, analyzing the kurtosis of the three-dimensional crack surface according to the three-dimensional crack surface numerical model includes: performing kurtosis analysis on the three-dimensional crack surface according to a calculation result of a three-dimensional crack surface kurtosis expression, and the three-dimensional crack surface kurtosis expression is as follows: ; in, It is expressed as kurtosis, which is used to characterize the peak height of the probability density distribution curve at the mean value, and is also used to describe the flat state of the point cloud height distribution on the crack surface. is the mean height of the point cloud, σ is the standard deviation of point cloud height, n Represents a positive integer. In order to analyze the overall morphology of the three-dimensional crack surface more carefully and comprehensively, the present invention introduces a characteristic parameter of kurtosis, which is defined by the mean value of the point cloud height, the standard deviation of the point cloud height and the number of regional data points. Only one kurtosis parameter can be used to judge the flatness of the crack surface and the peak height of the probability density distribution curve at the average value.

[0014] In a second aspect, the system for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials provided by the present invention comprises a scanning device, a processor, an output device, and a memory, wherein the scanning device, the processor, the output device, and the memory are interconnected, wherein the memory is used to store a computer program, the computer program comprises program instructions, the processor is configured to call the program instructions, and the system uses the method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials.

[0015] The morphological feature analysis system of the three-dimensional crack surface of rock blasting materials provided by the present invention has a high degree of integration, and information transmission between various components is smooth. It can quickly analyze the three-dimensional morphology of the crack surface under the blasting load and obtain the analysis results, and it is easier to find the origin and propagation path of the crack, so as to take measures to deal with it more quickly; the system can be used for the construction of underground engineering facilities, and the appropriate blasting method can be selected by timely analyzing the morphological features of the three-dimensional crack surface, thereby improving the safety and long-term stability of the construction of underground engineering facilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the flow of a method for analyzing the morphological characteristics of a three-dimensional crack surface of a rock blasting material according to an embodiment of the present invention; Figure 2 It is a schematic diagram of the internal and external model of the explosion test of an embodiment of the present invention; Figure 3 Schematic diagram of the crack expansion evolution process during the PMMA blasting process according to an embodiment of the present invention; Figure 4 A schematic diagram of crack propagation during slotting blasting according to an embodiment of the present invention; Figure 5 It is a schematic diagram of the three-dimensional morphology chromatography processing flow of the crack surface according to an embodiment of the present invention; Figure 6 It is a schematic diagram of the three-dimensional morphology spectrum of crack surfaces in different regions of an embodiment of the present invention; Figure 7A schematic diagram of the distribution of maximum height and variance values ​​of crack surface point cloud data according to an embodiment of the present invention; Figure 8 Schematic diagram of the frequency distribution histogram of the crack surface height according to an embodiment of the present invention; Fig. 9 Schematic diagram of the structure of a system for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not need to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, software or methods are not specifically described.

[0018] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

[0019] See also Figure 1 The embodiment of the present invention provides a method for analyzing the morphological characteristics of a three-dimensional crack surface of a rock blasting material, the method comprising the following steps: S1. Obtain image information of the three-dimensional crack propagation evolution process of the transparent brittle rock material under the blasting load to be studied.

[0020] See also Figure 2 , Figure 2 is the internal and external model diagram of the blasting test, where: Figure 2 (a) is a PMMA blasting system, which includes four parts: a three-dimensional scanner, a timing control device, a PMMA model, and a laptop computer. The blasting process of the blasting system is to control the position of explosives by using a blockage to make all blastholes charged at the same level, thereby ensuring that the energy of each blasthole is released in a concentrated manner during the blasting process. At the same time, according to the test delay design, the blasting blastholes of the same section are connected in series to the same blasting channel, and the blastholes of different sections are connected in parallel to different blasting channels, and the delay time is set by the timing control device. Figure 2(b) is a blasthole distribution diagram, wherein the blastholes are distributed at the top center, the blastholes and the empty holes are 8 cm deep, the blasthole diameters are 4 mm, and the empty hole diameters are 8 mm. Figure 2 (c) is a schematic diagram of a PMMA model, wherein the PMMA model is a plexiglass with a model size of 20 cm×20 cm×20 cm. Figure 2 (d) is a diagram of the actual charge structure, in which the explosive is carboxymethyl cellulose lead azide, continuous coupling charge is used, the single hole charge is 70 mg, the charge height is 7 mm, and the filling height is 20 mm. In the process of obtaining the image information of the three-dimensional crack extension evolution process, the three-dimensional scanner device used includes but is not limited to a three-dimensional image camera, which is set at 2m away from the PMMA model to capture the crack generation and extension process during the blasting process. In this embodiment, the three-dimensional image high-speed camera includes four modules: content setting, scanning record, image processing, and image output. During implementation, the timing control device is first used to accurately control the delay time between each blast hole, wherein the initial sampling time is set in three sections, the delay time between sections is set to 10ms, and the delay time between the same section is set to 0.2ms. Then, in the content setting module in the three-dimensional image camera, the sampling frequency of the three-dimensional image camera is set to 10000 frames / second, and the resolution is set to 682×764. Next, blasting is performed, and the three-dimensional image camera collects blasting image information through a scanning and recording module combined with a timing control device. The collected results are processed by an image processing module, and finally the image information is output through an image output module, and the image information is displayed through a laptop. The advantage of this method is that it can capture the generation and expansion images of three-dimensional cracks in different time periods, present the complex crack surface evolution process through simple images, and facilitate the visual analysis of the three-dimensional crack expansion evolution process.

[0021] S2. Obtain data point information of the three-dimensional crack propagation evolution process of the transparent brittle rock material under the blasting load to be studied.

[0022] In the process of obtaining the data point information of the three-dimensional crack growth evolution process, the 3D FreeScan combo metrology-grade 3D laser scanner was used. The blasting system that meets the requirements is as follows: Figure 2As shown, the three-dimensional image scanner can be replaced, and the difference between the three-dimensional image scanner and the three-dimensional image scanner is that the scanning results are different. The former is the image information obtained, and the latter is the data point information obtained. In this embodiment, the three-dimensional scanner includes four modules: content setting, scanning record, data processing, and data output. During implementation, in the content setting module of the three-dimensional scanner, the scanning point distance accuracy of the three-dimensional scanner is set to 0.01mm~3.0mm, the scanning frequency is set to 2250000 points / second, the scanning volume accuracy is set to 0.02mm+0.033mm / m, the scanning area is set to 500mm×500mm, the maximum scanning depth of field is set to 360mm, and the scanning mode is set to deep hole scanning and lightless mode. Then, by using the scanning and recording module of the three-dimensional scanner to scan the blasting crack surface at different positions, the data point information of the blasting crack surface at different positions is obtained, and the data point information is called "point cloud data". The data point information of the blasting surface at different positions is processed by the data processing module, and finally the acquired data point information is output by the data output module, and the data point information is processed by the data processing software of the laptop. The scanner that uses the scanning data points is easier to capture the information of the crack extension surface inside the blasting image than the scanner that uses the scanning image information. The three-dimensional image scanner is mainly used to obtain the three-dimensional crack extension and evolution process information, and the three-dimensional data point scanner is mainly used to obtain the surface information of the three-dimensional crack extension and evolution results. Both methods are indispensable to this analysis method and are conducive to the visualization analysis of the three-dimensional crack extension evolution process. The advantage of this method is that on the one hand, it can more accurately capture the data in the blasting process, and on the other hand, it very cleverly combines the data with the data processing software, thereby effectively reconstructing the internal full picture of the three-dimensional crack extension surface.

[0023] S3. Based on the image information of the three-dimensional crack surface expansion evolution, the three-dimensional crack expansion law and morphological characteristics are analyzed.

[0024] See also Figure 3 , Figure 3It is an image of the crack expansion evolution process during the PMMA blasting process, which contains 12 images (a)-(m), etc. The crack expansion evolution process image is divided into three time periods, and the three time periods are (a)~(d), (e)~(h), (i)~(m), wherein the initial time of the first time period is set to 0ms, and the delay time of the interval is set to 0.2ms, the initial time of the second time period is set to 10ms, and the delay time of the interval is set to 0.2ms, and the initial time of the third time period is set to 20ms, and the delay time of the interval is set to 0.2ms. In this embodiment, the setting of the delay time is realized by the timing control device. Before the timing control device sets the delay time, it is necessary to use the blockage to control the position of the explosive so that all the blast holes are charged at the same level to ensure that the energy of each blast hole is released in a concentrated manner during the blasting process. At the same time, the blast holes of the same section are connected in series to the same blasting channel, and the blast holes of different sections are connected in parallel to different blasting channels. When the blasting load acts on the wall of the blasthole, radial cracks initiate around the blasthole, and the crack expansion and penetration are accelerated by the gas generated by the blasting. Figure 3 The graphs of the three time periods shown in the figure reveal the process from crack generation to evolution and expansion. Figure 3 As shown in the figure (a), after the first explosion, the explosion energy quickly fills the entire blast hole. First, radial cracks are formed around the blast hole. The generation of the radial cracks is as follows: Figure 3 (b) As shown. Driven further by the gas generated by the blast, some cracks extend to the blasthole without explosives and form a through crack surface, thus forming an initial groove cavity. At the same time, an axial fan-shaped crack is formed at the bottom of the blasthole. As the depth increases, the extrusion constraint effect becomes greater, resulting in the axial crack surface extension range being significantly smaller than the radial crack, as shown in Figure 2. Figure 3 (c). Eventually, as the energy driving the crack growth is rapidly released, the crack growth stops, as shown in Figure 3 As shown in (d). When the first blast hole was detonated, a large number of secondary weak planes were generated around it. The energy released by the second blast hole continued to act on the weak planes. The combined effect of stress waves and the gas generated by the blast caused the radial cracks around the blast hole to continue to expand rapidly, thus penetrating to form a fractured block. Among them, the axial crack at the bottom of the blast hole was secondary excited and penetrated to the edge of the model, forming a crack surface parallel to the plane where the two blast holes were located, as shown in Figure 1. Figure 3 (e) ~(h). Figure 3As shown in (i) to (m), after the third section of the blasthole was detonated, the explosion energy continued to advance with the detonation of the first blasthole, and continued to accelerate the expansion of the radial cracks, and formed a main crack in the shape of an "inverted triangle". The main crack runs through the entire groove area, causing the blasting groove cavity to further expand and form the final blasting groove cavity. Since the axial crack surface has been formed, the blasting energy quickly leaks out from the crack surface, resulting in only a small number of cracks around the blasthole perpendicular to the crack surface.

[0025] See also Figure 4 , Figure 4 is the crack propagation morphology diagram during slotting blasting, where 4(a) is the morphology diagram of the three-dimensional crack. Figure 4 (b) is the top view of the three-dimensional crack. Figure 4 (c) is the left view of the three-dimensional crack. Figure 4 (d) is a front view of a three-dimensional crack. In this embodiment, the detonation of the blasthole is controlled by using a timing control device to set multiple detonation delay times, and then the crack expansion evolution graph after detonation is observed. Analysis shows that the crack expansion process under simultaneous detonation conditions is significantly different from the crack expansion process under multi-stage detonation conditions. Under multi-stage detonation conditions, as the delay time is set, the explosion energy continues to act on the medium, and the cracks are stimulated and expanded multiple times. Figure 4 As shown in (a), under the condition of multi-stage detonation, the initial cracks are rapidly generated around the blasthole wall, and the gas generated by the blasting drives the cracks to continue to expand, eventually forming arc-shaped or "ear"-shaped cracks. Due to the influence of factors such as the model boundary effect, the axial main crack continues to expand through the entire model, forming a through-type crack surface. Figure 4 (b), the cracks are numbered. Under the action of the second blast hole, crack No. 1 and crack No. 2 are connected and extended to the entire model boundary to form the largest crack surface. At the same time, derivative cracks No. 3 and No. 4 are formed in the starting area of ​​crack No. 1, and the length of the derivative cracks is significantly smaller than the length of the main crack No. 1. Since a large number of through-type cracks have been generated inside the model by the previous blast hole blasting, a large amount of gas generated by the blast escaped from the cracks after the third blast hole was detonated, resulting in shorter crack extensions around the blast holes, such as cracks No. 5 and No. 6. Therefore, it can be summarized as follows: the generation and extension of cracks caused by the blasting load can be divided into two main stages: In the first stage, at the moment of the explosion of the explosive, a large amount of energy is released to the surroundings in the form of a shock wave and acts on the medium, so that radial initial cracks are formed around the blast hole. The cracks generally only appear around the blast hole, and the crack length is short, and the crack density per unit area is high. In the second stage, the gas generated by the blast drives the generation of ear-shaped cracks, such as Figure 4(c) and 4(d). As the gas penetrates into the crack, the crack continues to expand outward until the gas effect disappears. The crack generally starts around the blast hole, and the crack end is semicircular or ear-shaped, with a wider expansion range. Compared with other cracks, it is easier to penetrate the medium to form a crack surface, which is also the main reason for medium damage and breakage. The advantage of the analysis method is that it uses a three-dimensional image scanner to obtain the crack images generated during the explosion in stages, successfully solving the difficulty of observing crack expansion and morphology due to the rapid explosion process, and realizing the visual observation of cracks, laying a solid foundation for studying the morphological characteristics of three-dimensional crack surfaces.

[0026] S4. Constructing a three-dimensional numerical model based on the data point information of the three-dimensional crack surface extension evolution.

[0027] See also Figure 5 , Figure 5 It is a three-dimensional morphology chromatogram processing flow chart of the crack surface, and the three-dimensional morphology chromatogram processing flow chart includes four parts, namely, the blast crack surface, the crack surface point cloud data, the crack surface point cloud file, and the crack surface three-dimensional morphology chromatogram. The construction of the crack surface three-dimensional morphology chromatogram is to construct a three-dimensional numerical model of the crack surface. In this embodiment, in the process of constructing the three-dimensional numerical model of the crack surface, it is necessary to first use a 3D laser scanner to scan and obtain the point cloud data file at the blast crack surface, and then import the point cloud data file obtained by the 3D laser scanner into the Geomagic studio software for noise reduction and hole filling processing, and encapsulation. Next, the encapsulated file is imported into the MATLAB software, the "Height" algorithm is used to extract and calculate the surface height value, and the "Colormap" statement is used to assign different height values ​​of the surface to the chromatogram to form a three-dimensional morphology chromatogram of the crack surface. Due to the different failure modes and rupture angles of different crack surfaces, the three-dimensional morphology of the crack surface is quite different. Therefore, the area selected by the crack surface must be able to reflect the morphological characteristics of the entire crack surface, while minimizing the amount of calculation.

[0028] See also Figure 6 , Figure 6 It is a three-dimensional morphology chromatogram of crack surfaces in different areas. Figure 6 (a) is the feature region selection map, Figure 6 (b) to (e) are three-dimensional morphology chromatograms. In this embodiment, MATLAB data processing software is used to generate characteristic region three-dimensional morphology chromatograms, which more vividly describe the morphological characteristics of the gas-generated crack surface in different regions, such as Figure 6(b) ~ (e) are shown. Different colors react to the surface flatness of the crack produced by the gas. The greater the color contrast, the greater the height difference of the crack surface, which also means the worse the flatness. It can be seen that with the combined effect of the explosion stress wave and the gas, the crack surface in the near area of ​​crack extension (area 1, 2) has obvious undulations, accompanied by deeper concave and more obvious sharp protrusions, showing a significant "rugged shape". With the expansion of the crack, in the middle and far areas of the explosion (area 3, 4), the wavelength of the undulation of the crack surface increases significantly, gradually forming a "slope surface". As the three-dimensional crack tip continues to expand, the crack surface gradually becomes flat and there is no obvious "wave-like" undulation. At the same time, due to the further forward expansion of the crack tip driven by the gas in the later stage, some fine radial cracks appear on the crack surface (area 5). The advantage of the method is that the three-dimensional model of the crack surface is reconstructed through the data processing software, and the invisible crack surface height data point information is converted into a tangible color graphic, which makes it difficult to study and easy to study, making the analysis more systematic and the results more reliable.

[0029] S5. Based on the three-dimensional numerical model, perform morphological feature analysis on the three-dimensional crack surface.

[0030] The morphological feature analysis of the three-dimensional crack surface includes crack surface height difference and flatness analysis and crack surface skewness and kurtosis analysis. In this embodiment, by using MATLAB software, expressions for height difference, flatness, skewness, and kurtosis are set, and the relevant height value information of the three-dimensional morphology chromatogram is extracted, substituted into the expression for calculation and obtaining the calculation result, and then the morphological feature analysis of the three-dimensional crack surface is performed based on the image generated by the calculation result.

[0031] See also Figure 7 , Figure 7 is the maximum height value and variance value distribution diagram of the crack surface point cloud data, where Figure 7 (a) is the maximum height value of the crack surface point cloud data, Figure 7 (b) is the variance value of the crack surface point cloud data. Figure 7As shown in the figure, with the increase of the expansion distance, the maximum height and variance value of the micro-convex body on the crack surface both show a trend of increasing first and then decreasing, with a large fluctuation range. Among them, in the area 1 to area 2 around the blasthole, the height value increased from 4.2mm to 4.8mm, an increase of 14.3%, and the variance value increased from 0.796 to 0.817, an increase of 2.6%, indicating that the discreteness of the crack surface point cloud data in the near area of ​​blasting is large, the crack surface fluctuates significantly, and large faults are prone to occur. Since the blasting shock wave directly acts on the periphery of the blasthole, the crack generation mode of the surrounding medium is mainly compression and tension damage, and the crack surface flatness is poor. With the increase of the expansion distance, the maximum height value from area 2 to area 3 decreases, but the decrease is not obvious, and it basically remains at 4.7mm. However, the variance value decreases to 0.648, a decrease of 20.7%, indicating that in the process of changing the distance from the near area of ​​blasting to the middle and far area, the overall height difference of the crack surface is large, and the overall flatness of the crack surface is relatively flat compared with the near area of ​​blasting. As the expansion distance increases, the blasting shock wave decays into a stress wave, and the gas generated by the blasting fills the crack. At this time, the expansion of the crack is driven by the stress wave and the gas generated by the blasting, and the generation of the crack gradually changes from tensile failure to shear failure. As the expansion distance increases, the crack surface height value decreases rapidly. The maximum height value of area 4 is only 3.2mm, which is 31.9% lower than that of area 3, and the corresponding variance value is 0.728. As the expansion distance increases, the stress wave gradually decays, the gas pressure generated by the blasting decreases, and the ability to drive crack expansion is weakened. The maximum height value of the crack surface in area 5 is 3.7mm, and the variance value is reduced to 0.586, which is 19.5% lower. As the blasting area space increases, the crack generation mode gradually changes, the crack surface migration space is affected, the relative height value of the micro-convex body is significantly reduced, and the overall distribution uniformity and flatness of the crack surface gradually improve. The advantage of the analysis method is that a large amount of data point information on the crack surface is processed, and finally only two data results can be used to judge the overall distribution uniformity and flatness of the crack surface.

[0032] See also Figure 8 , Figure 8 is the frequency distribution histogram of the crack surface height, where Figure 8 (a) ~ (e) correspond to areas 1 ~ 5 respectively. Figure 8As shown in the figure, for the near-blasting areas 1 and 2, the skewness and kurtosis of the height frequency distribution of the micro-convex bodies on the crack surface are both greater than 0, indicating that the number of surface concave-convex bodies above the average height value is greater than the number of concave-convex bodies below the average height value, and the height distribution of the entire crack surface is obviously uneven. When the extension distance increases, in the middle and far-blasting areas 3, 4, and 5, the formation of the crack surface gradually changes from tensile failure to shear failure, the skewness value of the height frequency distribution decreases, the kurtosis value is less than 3, and the uniformity of the height distribution of the crack surface increases. When the extension distance continues to increase, the skewness value continues to increase, the kurtosis value continues to decrease, the number of concave-convex bodies below the height average value on the crack surface increases, but the overestimation difference of the concave-convex bodies decreases, and the crack surface morphology becomes smoother.

[0033] The summary is as follows: in the process of cracks driven by the gas and stress waves generated by the explosion extending outward from the center of the crack surface, the height difference and variance values ​​first increase and then decrease, the skewness value first decreases and then increases, the kurtosis value keeps decreasing, and the fluctuation amplitude of the crack surface formed gradually changes from large to small; the cracks generated by tensile failure have a larger three-dimensional expansion amplitude than the cracks generated by shear failure; the expansion amplitude of the primary crack is larger than that of the secondary crack; the expansion amplitude of the secondary crack gradually decays.

[0034] See also Fig. 9 , Fig. 9 The morphological feature analysis system of the three-dimensional crack surface of the rock blasting material in the embodiment of the present invention includes a scanning device, a processor, an output device, and a memory, wherein the scanning device, the processor, the output device, and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, the processor is configured to call the program instructions, and the system uses the morphological feature analysis method of the three-dimensional crack surface of the rock blasting material. In this embodiment, the scanning device is used to scan and obtain data information of the blasting crack surface, the processor is configured to call the program instructions and process and calculate the data information of the blasting crack surface, the memory is used to store the program instructions, and the output device is used to display the calculation results and analysis results processed by the processor.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials, characterized in that: The steps include: Obtain the three-dimensional crack surface characteristic information of the transparent brittle rock material under the blasting load to be studied; Analyzing the three-dimensional crack propagation law and morphological characteristics using the three-dimensional crack surface feature information; Constructing a three-dimensional crack surface numerical model based on the analysis results of the three-dimensional crack propagation law and morphological characteristics; The morphological characteristics of the three-dimensional crack surface are analyzed according to the three-dimensional crack surface numerical model.

2. The method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to claim 1 is characterized in that: The method of obtaining the three-dimensional crack surface characteristic information of the transparent brittle rock material under the blasting load to be studied includes: Obtain image information of the three-dimensional crack growth evolution process; Get three-dimensional crack surface data point information.

3. The method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to claim 1 is characterized in that: The analyzing the three-dimensional crack propagation law and morphological characteristics by using the three-dimensional crack surface characteristic information includes: Under the multi-stage detonation state, the three-dimensional crack surface feature information is used to analyze the three-dimensional crack expansion law and morphological characteristics.

4. The method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to claim 1, characterized in that: The three-dimensional crack surface numerical model is constructed based on the analysis results of the three-dimensional crack propagation law and morphological characteristics, including: Based on the analysis results of the three-dimensional crack propagation law and morphological characteristics, a three-dimensional model of the crack surface morphology chromatogram is constructed.

5. The method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to claim 1, characterized in that: The performing morphological feature analysis on the three-dimensional crack surface according to the three-dimensional crack surface numerical model comprises: Analyzing the height difference of the three-dimensional crack surface according to the three-dimensional crack surface numerical model; Analyzing the flatness of the three-dimensional crack surface according to the three-dimensional crack surface numerical model; Analyzing the deflection of the three-dimensional crack surface according to the three-dimensional crack surface numerical model; The three-dimensional crack surface kurtosis is analyzed according to the three-dimensional crack surface numerical model.

6. A method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to claim 5, characterized in that: The analyzing the height difference of the three-dimensional crack surface according to the three-dimensional crack surface numerical model comprises: The height difference analysis of the three-dimensional crack surface is performed according to the calculation result of the height difference expression of the three-dimensional crack surface, and the height difference expression is as follows: ； in, It is expressed as the relative height value of any point on the crack surface. It is expressed as the absolute height value of any point on the crack surface. n Expressed as a positive integer.

7. The method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to claim 5, characterized in that: The analyzing the flatness of the three-dimensional crack surface according to the three-dimensional crack surface numerical model comprises: The flatness analysis of the three-dimensional crack surface is performed according to the calculation result of the three-dimensional crack surface flatness expression. The flatness expression includes the average value expression of the three-dimensional crack surface height and the variance value expression of the three-dimensional crack surface micro-convex height, which are as follows: ； ； in, It is expressed as the average value of all heights of the three-dimensional crack surface, It is expressed as the height variance of the micro-convex body on the three-dimensional crack surface. It is expressed as the relative height value of any point on the crack surface. n Expressed as a positive integer.

8. The method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to claim 5, characterized in that: The analyzing the deflection of the three-dimensional crack surface according to the three-dimensional crack surface numerical model comprises: The skewness analysis of the three-dimensional crack surface is performed according to the calculation result of the three-dimensional crack surface skewness expression, and the three-dimensional crack surface skewness expression is as follows: ； in, It is expressed as skewness, which is used to describe the direction and degree of skewness of data distribution, and is also used to describe the asymmetry of the high-speed frequency distribution of point clouds on the crack surface. It is represented as the mean value of the point cloud height, σ is represented as the standard deviation of the point cloud height, n Expressed as a positive integer.

9. The method for analyzing the morphological characteristics of three-dimensional crack surfaces of rock blasting materials according to claim 5, characterized in that: The analyzing the kurtosis of the three-dimensional crack surface according to the three-dimensional crack surface numerical model comprises: The kurtosis analysis of the three-dimensional crack surface is performed according to the calculation result of the three-dimensional crack surface kurtosis expression, and the three-dimensional crack surface kurtosis expression is as follows: ； in, It is expressed as kurtosis, which is used to characterize the peak height of the probability density distribution curve at the mean value, and is also used to describe the flat state of the point cloud height distribution on the crack surface. Expressed as the mean height of the point cloud, σ Expressed as the standard deviation of point cloud height, n Expressed as a positive integer.

10. A system for analyzing the morphological characteristics of a three-dimensional crack surface of a rock blasting material, the system using a method for analyzing the morphological characteristics of a three-dimensional crack surface of a rock blasting material according to any one of claims 1 to 9, characterized in that: The system includes a scanning device, a processor, an output device, and a memory, which are interconnected. The memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions.

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