Dyeing calibration-based gangue filling material compaction deformation test method

Abstract

The invention discloses a method for testing compaction deformation of a gangue filling material based on dyeing calibration, which specifically comprises the following steps of: 1, crushing gangue, and dyeing gangue particles in different particle size ranges by adopting different colors; 2, the dyed gangue particles are evenly mixed to serve as a gangue carrier, and then the gangue carrier is put into a detachable steel cylinder; 3, opening a semicircular cavity of the detachable steel cylinder, and collecting image information of the middle section of the gangue carrier; 4, tightly connecting the two semicircular cavities of the detachable steel cylinder, and carrying out a compression test on the gangue particles in the detachable steel cylinder; 5, after the compression test is completed, opening a semicircular cavity, and obtaining image information of the middle section of the compressed gangue carrier; and 6, processing and analyzing the images before and after the compression test to obtain the compression and crushing characteristics of the gangue carrier. The method can quantitatively analyze the development and distribution result of the fracture at the internal section of the gangue carrier.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanics, and in particular relates to a method for testing compaction deformation of gangue filling materials based on dyeing calibration. Background Art

[0002] Gangue is a solid waste produced during coal mining and washing. Long-term storage of gangue on the ground seriously damages the ecological environment and threatens the health of residents. It is of great significance to achieve large-scale disposal of gangue. At present, the solid filling mining technology is to transport the waste to the goaf through specific transportation equipment after coal mining at the working face, and fill the goaf to support the roof and control the movement and deformation of the overburden. It not only solves the problem of "three-down" coal pressure (referring to the pressure of coal under railways, water bodies and buildings), but also solves the problem of handling solid waste in mines. It has become a key technology for realizing green mining of coal mines. The bearing capacity of the gangue bearing body is the core influencing factor of the movement control of the rock layer in solid filling mining. The existing laboratory test method only conducts uniaxial confined compression tests on the gangue bearing body to study its compaction characteristics at the macro level, and lacks research on the microscopic compaction and deformation characteristics inside the stone bearing body. Summary of the invention

[0003] Purpose of the invention: In order to solve the problems existing in the above-mentioned prior art, the present invention provides a compaction deformation test method of gangue filling materials based on dyeing calibration.

[0004] Technical solution: The present invention discloses a method for testing compaction deformation of gangue filling materials based on dyeing calibration, comprising the following steps:

[0005] Step 1: crush the gangue, and dye the gangue particles in different particle size ranges with different colors;

[0006] Step 2: Mix the dyed gangue particles evenly according to the natural ratio as the gangue carrier, and then put them into a detachable steel cylinder; the detachable steel cylinder includes two semicircular cavities and a bottom plate, the two semicircular cavities are connected to each other to form a circular barrel wall, and the circular barrel wall is fixed on the bottom plate;

[0007] Step 3: Open a semicircular cavity and collect image information of the middle section of the gangue bearing body in the removable steel cylinder;

[0008] Step 4: Tightly connect the two semicircular cavities and use a press to perform a compression test on the gangue particles in the detachable steel cylinder;

[0009] Step 5: After the compression test is completed, a semicircular cavity is opened to obtain image information at the middle section of the gangue bearing body after compression;

[0010] Step 6: Process and analyze the images before and after the compression test to obtain the compression and crushing characteristics of the gangue carrier.

[0011] Furthermore, the method also includes selecting a suitable gangue bearing body to fill the goaf according to the compression and crushing characteristics of the gangue bearing body obtained and the characteristics of the goaf.

[0012] Furthermore, the two semicircular cavities are connected to each other by bolts.

[0013] Furthermore, the detachable steel cylinder also includes a pressure rod and a pressure plate, wherein the pressure plate is arranged on the top of the pressure rod, the bottom of the pressure rod is arranged on the base, and the pressure rod is arranged in a circular barrel formed by two semicircular cavities.

[0014] Furthermore, the specific method for obtaining the image information at the middle section of the gangue carrier in step 3 or step 5 is: limiting the gangue carrier by a pressure plate, then placing the detachable steel cylinder horizontally, removing a semicircular cavity, and taking out the gangue particles in the semicircular cavity, thereby exposing the middle section of the gangue carrier.

[0015] Furthermore, a transparent film is provided on the inner wall of the detachable steel cylinder, and the transparent film is a polyethylene film.

[0016] Furthermore, the method for processing and analyzing the image in step 6 is specifically as follows:

[0017] A1. Import the image into PCAS software, use the RGB segmentation function of the software, adjust the interpolation of the selected color area by changing the tolerance to select more particle areas, set the selected area to black and the unselected area to white, and obtain a binary image;

[0018] A2. Use the Closing-Smooth option to smooth the crack edges in the binary image obtained in step A1, remove the redundant black and white spots through Black spots and White spots, use the Enclose regions option to repair the identified cracks, and finally use Auto analysis-Crack to count the information of the crack network blocks of gangue crushing;

[0019] A3. Use the Crack option to select the width of the crack, and click the Skeletons option to obtain the central axis of the crack skeleton of the gangue crushing. Finally, click the Crackproperty table to obtain the geometric information table of the broken gangue crack including: length, width and direction.

[0020] Furthermore, before dyeing the gangue particles, the gangue particles are washed and placed in a drying oven at 100° C. for 24 hours. After dyeing, the gangue particles are placed in a vacuum cylinder for 8 hours, taken out, and then placed in a drying oven at 35° C. for 4 hours.

[0021] Furthermore, the particle size ranges of the gangue particles are divided into 5-10mm, 10-15mm, 15-20mm, 20-30mm, 30-40mm, and 40-50mm.

[0022] Beneficial effects: The present invention conducts on-site sampling of a mine where solid filling coal mining is carried out, crushes the sampled gangue into different particle size groups, and performs uniaxial confined compression tests on the gangue particles of different particle size groups by dyeing and calibrating them respectively, so as to more accurately obtain the distribution characteristics of the gangue particles at the middle cross section of the gangue bearing body before and after compression, and quantitatively analyzes the development and distribution results of cracks at the internal cross section of the gangue bearing body by using PCAS image processing software. The method is intuitive, novel, and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the present invention;

[0024] Figure 2 This is the overall structural diagram of the detachable steel cylinder of the present invention;

[0025] Figure 3 Schematic diagram of the detachable steel cylinder of the present invention, wherein (a) is a front view of the detachable steel cylinder of the present invention, and (b) is a cross-sectional view of the detachable steel cylinder of the present invention. DETAILED DESCRIPTION

[0026] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0027] like Figure 1 As shown, a method for testing compaction deformation of gangue filling materials based on dyeing calibration in this embodiment specifically includes the following steps:

[0028] (1) Raw material crushing and screening: The gangue sampled on site is crushed and graded by a vibrating screen. The graded particle sizes are: 5-10mm, 10-15mm, 15-20mm, 20-30mm, 30-40mm, 40-50mm.

[0029] (2) Staining calibration of gangue of different particle sizes: The gangue sieved in step (1) is washed and placed in a drying oven at 100°C for 24 hours, and then the gangue particles are dyed. In a vacuum cylinder, five dyes of yellow, black, blue, green and red are used to adsorb and dye the gangue of five particle size groups of 10-15 mm, 15-20 mm, 20-30 mm, 30-40 mm and 40-50 mm (the gangue particles of 5-10 mm retain their original color). During this process, the vacuum cylinder is evacuated to 0.1 atmospheres, and after standing for 8 hours, the gangue sample is taken out and placed in a drying oven at 35°C for drying for 4 hours.

[0030] (3) Image acquisition at the middle section of the gangue bearing body before compression: The required gangue mass is calculated to be 15 kg based on the volume of the steel cylinder and the density of the sampled gangue. The gangue is loaded according to the natural grading, which are 5-10 mm: 8.27%, 10-15 mm: 14.11%, 15-20 mm: 11.53%, 20-30 mm: 28.37%, 30-40 mm: 16.56%, and 40-50 mm: 21.16%. Add a thin and soft polyethylene film in the middle of the detachable steel cylinder, mix the gangue evenly according to the natural ratio and put it into the detachable steel cylinder, smooth the upper surface of the solid filling material sample, and after filling, open half of the cavity in the detachable steel cylinder to collect images of the gangue blocks at the cross section, set the camera 30 cm vertically above the gangue block to shoot, and manually adjust the focal length to obtain the clearest image of the gangue particles before loading.

[0031] like Figure 2 As shown in FIG. 3, the detachable steel cylinder of this embodiment includes two left and right semicircular cavities 2, 3, a bottom plate 5, a pressure rod 1 and a bolt 4. The two left and right semicircular cavities are locked by bolts to form a circular barrel wall. The circular barrel wall is locked with the bottom plate by bolts to form a mold cavity. The pressure rod can slide up and down in the cavity to complete the compression function of the gangue in the cavity.

[0032] (4) Axial loading: Assemble the steel cylinder and tighten the bolts on both sides, place it on a press to carry out a uniaxial lateral confinement compression test, with a maximum axial pressure of 20 MPa and an axial pressure applied at a speed of 0.2 mm / s. Record the stress level and compression height of the gangue filling body measured by the pressure system.

[0033] (5) Image acquisition at the middle section of the gangue bearing body after compression: Remove the steel cylinder from the press, remove the bolts, and push the gangue bearing body apart from the middle. Similarly, take a picture 30 cm vertically above the gangue block to obtain image information at the middle section of the gangue bearing body after compression.

[0034] The specific method for obtaining the image information at the middle section of the gangue carrier is as follows: the gangue carrier is limited by a pressure plate, and then the detachable steel cylinder is placed horizontally, a semicircular cavity is removed, and the gangue particles in the semicircular cavity are taken out, thereby exposing the middle section of the gangue carrier.

[0035] (6) Image processing of the middle section of the gangue carrier after loading:

[0036] 1) Import the image into PCAS software, select the Segmentation option, and the binarization window will pop up. Click 'use RGB segmentation'. Click on any size of gangue particle on the image to display the R, G, and B values ​​of the color. Each color in the image can be represented by a combination of the three primary colors RGB.

[0037] 2) Through the tolerance, the interpolation of the selected color area can be adjusted to select a more accurate particle area. Through repeated tests, it is generally taken to be around 22. Repeatedly select and extract colors, adjust the Tolerance value to improve the recognition accuracy until the cracks in the gangue particles can be completely selected, set the selected area to black, and the unselected area to white, obtain a binary image, and then use the software's built-in function to reduce the noise of the image. Return to the main interface of the software to perform statistical analysis on the particle size of the identified gangue particles;

[0038] 3) Return to the main interface of the software. If the edge of the gangue crack is rough, you can use the 'Closing (Smooth)' option to smooth the edge of the crack. Adjust the radius of the smoothing element according to the size of the image (usually about 3 pixels).

[0039] 4) Click 'Black spots' and 'White spots' to remove the extra black and white spots. The 'Enclose regions' option is used to repair the identified cracks. Then click the 'Auto analysis (Crack)' option to calculate the information of the crack network blocks of the gangue crushing.

[0040] 5) Click the 'Crack' option, set the 'Protect width' option (i.e. select the width of the crack), and click the 'Skeletons' option to obtain the central axis of the crack skeleton of the broken gangue. Finally, click the 'Crackproperty table' to obtain the geometric information table of the broken gangue cracks, including: length, width and direction, etc.

[0041] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for testing compaction deformation of waste rock filling materials based on dyeing calibration, characterized in that: The steps include: Step 1: crush the gangue, and dye the gangue particles in different particle size ranges with different colors; Step 2: Mix the dyed gangue particles evenly according to the natural ratio as the gangue carrier, and then put them into a detachable steel cylinder; the detachable steel cylinder includes two semicircular cavities and a bottom plate, the two semicircular cavities are connected to each other to form a circular barrel wall, and the circular barrel wall is fixed on the bottom plate; Step 3: Open a semicircular cavity and collect image information of the middle section of the gangue bearing body in the removable steel cylinder; Step 4: Tightly connect the two semicircular cavities and use a press to perform a compression test on the gangue particles in the detachable steel cylinder; Step 5: After the compression test is completed, a semicircular cavity is opened to obtain image information at the middle section of the gangue bearing body after compression; Step 6: Process and analyze the images before and after the compression test to obtain the compression and crushing characteristics of the gangue carrier.

2. The method for testing compaction deformation of waste rock filling materials based on dyeing calibration according to claim 1, characterized in that: The method also includes selecting a suitable gangue bearing body to fill the goaf according to the compression and crushing characteristics of the gangue bearing body obtained and the characteristics of the goaf.

3. The method for testing compaction deformation of waste rock filling materials based on dyeing calibration according to claim 1, characterized in that: The two semicircular chambers are connected to each other by bolts.

4. The method for testing compaction deformation of gangue filling materials based on dyeing calibration according to claim 1, characterized in that: The detachable steel cylinder also includes a pressure rod and a pressure plate, wherein the pressure plate is arranged on the top of the pressure rod, the bottom of the pressure rod is arranged on the base, and the pressure rod is arranged in a circular barrel formed by two semicircular cavities.

5. The method for testing compaction deformation of waste rock filling materials based on dyeing calibration according to claim 4, characterized in that: The specific method for obtaining the image information at the middle section of the gangue carrier in step 3 or step 5 is as follows: the gangue carrier is limited by a pressure plate, and then the detachable steel cylinder is placed horizontally, a semicircular cavity is removed, and the gangue particles in the semicircular cavity are taken out, thereby exposing the middle section of the gangue carrier.

6. The method for testing compaction deformation of gangue filling materials based on dyeing calibration according to claim 1, characterized in that: A transparent film is arranged on the inner wall of the detachable steel cylinder, and the transparent film is a polyethylene film.

7. The method for testing compaction deformation of gangue filling materials based on dyeing calibration according to claim 1, characterized in that: The method for processing and analyzing the image in step 6 is specifically as follows: A1. Import the image into PCAS software, use the RGB segmentation function of the software, adjust the interpolation of the selected color area by changing the tolerance to select more particle areas, set the selected area to black and the unselected area to white, and obtain a binary image; A2. Use the Closing-Smooth option to smooth the crack edges in the binary image obtained in step A1, remove the redundant black and white spots through Black spots and White spots, use the Enclose regions option to repair the identified cracks, and finally use Auto analysis-Crack to count the information of the crack network blocks of gangue crushing; A3. Use the Crack option to select the width of the crack, and click the Skeletons option to obtain the central axis of the crack skeleton of the gangue crushing. Finally, click the Crackproperty table to obtain the geometric information table of the broken gangue crack including: length, width and direction.

8. The method for testing compaction deformation of waste rock filling materials based on dyeing calibration according to claim 1, characterized in that: Before dyeing the gangue particles, wash the gangue particles and place them in a drying oven at 100°C for 24 hours. After dyeing, place the gangue particles in a vacuum cylinder for 8 hours, take them out, and then place them in a drying oven at 35°C for 4 hours.

9. The method for testing compaction deformation of waste rock filling materials based on dyeing calibration according to claim 1, characterized in that: The particle size range of gangue particles is divided into 5-10mm, 10-15mm, 15-20mm, 20-30mm, 30-40mm, and 40-50mm.

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