Physical similar simulation test device and physical similar simulation test method for tilted stratums

[0042] The embodiments of the present invention will be further described below in conjunction with the drawings.

[0043] Such as figure 1 As shown in --7, a physical similarity simulation test device for inclined rock formations is composed of an external frame, a tiltable frame, front and rear baffles, hydraulic support devices, and suspension lifting devices; among them:

[0044] The external frame includes two vertical columns 3, a transverse base 2, an upper beam 1 and a double pulley track 5. The horizontal base 2 is fixed on the ground by bolts, and a parallel double pulley track 5 is installed on the inner lower end surface of the upper cross beam 1. The left and right vertical uprights 3 are fixed together with the base 2 and the upper cross beam 1 by bolts.

[0045] The outer frame has a length of 5m, a height of 3.8m, and a width of 0.4m. Among them, the left and right columns are four-sided steel plates with length × width × height of 0.2m×0.3mm×3.6m respectively; the horizontal base 2 is the upper end face length of 5m, the lower end face length of 5.5m, the height of 0.4m, and the width of 0.4m. The upper crossbeam 1 is a four-sided steel plate with a length×width×height of 5m×0.4mm×0.4m. The distance between the double tracks inside the upper beam 1 is 0.15m.

[0046] The hydraulic supporting device includes a plurality of supporting jacks 14; the supporting jacks 14 are installed between the lateral base 2 of the outer frame and the tiltable frame;

[0047] The suspension lifting device is installed on the double pulley track 5 of the outer frame, and a horizontal jack 6 is arranged on the double pulley track 5; the horizontal jack 6 makes the suspension lifting device go back and forth on the double pulley track 5 Mobile; Suspension lifting device is composed of two electric motors 7, electric motor power wheels 8, sling 9, hook 10, pulley 4; two electric motors 7 are connected by steel plate 21;

[0048] The tiltable frame includes an inner frame 25, a movable beam 15, a loading jack 26, a pressure block 24, a guide rail 27, a lifting ring 11, and an angle ruler 16. The tiltable frame is integrally installed inside the external fixed frame and is connected to the outside There is a certain inclined space between the frames; the above-mentioned movable beam 15 is movably installed on the mullion of the inner frame 25, the loading jack 26 is installed on the top frame of the inner frame 25, and the bottom of the extension end of the loading jack 26 is welded with a bearing The pressure block 24; the above-mentioned lifting ring 11 is welded on both sides of the upper end surface of the inner frame 25; the bottom end of one side of the inner frame 25 is hinged with the outer frame base 2 through the rotating shaft 13, and the bottom of the inner frame 25 is supported on the supporting jack 14; The angle ruler 16 is mounted on the rotating shaft 13. The angle pointer 17 is fixed on the bottom surface of the inner frame 25 by bolts. The angle ruler 16 is engraved with a 0-90° angle scale. The 0 scale line is connected to the upper end surface of the outer frame base 2 and the inner frame 25 The junctions of the lower end surfaces of the bottom frame overlap, which can rotate with the tiltable frame to show the angle of inclination; the side frames of the inner frame 25, the bottom frame and the front and back sides of the movable beam 15 are all processed with opening slots along the length of the frame , A guide rail 27 is installed in the opening groove, and a number of buckles 28 with threaded holes are installed on the guide rail 27. The guide rail 27 is such as Figure 7 Shown

[0049] The above-mentioned inner frame 25 is 2.2m×0.3mm×2.8m in length×width×height respectively; among them, the side frame is a tetrahedral steel plate with length×width×height of 0.2m×0.3mm×2.8m respectively; the hydraulic loading device consists of It is composed of 6 loading jacks 26, each jack can be loaded in 2 levels; the pressure block 24 is a steel plate with a length × width × thickness of 0.33m×0.3mm×0.02m;

[0050] The front and rear baffles 12 are installed on the inner frame 25 and fastened with bolts 29 through the threaded hole buckles 28 to form a space for paving similar simulated materials in each rock formation.

[0051] The following describes the method of using the device of the present invention to perform a physical similarity simulation test of a tilted rock formation based on an example.

[0052] A certain coal mine is a sloping sandstone rock layer with an inclination angle of 50 degrees. For safe construction, physical and mechanical characteristics such as the cracking and movement law of the rock formation, the stress distribution and displacement changes of the surrounding rock are studied. Therefore, it is planned to conduct similar simulation tests on the rock formations and determine the rock formation test height to be 1.8 meters.

[0053] The test method is as follows:

[0054] The first step is to adjust the tilt angle of the tiltable rack

[0055] Such as figure 1 Shown: First determine the height of 1.8 meters to be filled in the tiltable frame of the similar model, and install the movable beam 15 at 1.8 meters;

[0056] Such as figure 2 As shown, the horizontal jack 6, the support jack 14 and the electrical switch of the suspension lifting device are activated, and the motor 7 drives the hook 10 on the sling 9 up and down, hooks the hoisting ring 11 of the tiltable frame, and makes the tiltable frame around The rotating shaft 13 rotates, and the lifting speed of the supporting jack 14 is the same as the lifting speed of the hook 10 of the suspension lifting device, and both are set to 2mm/s; at this time, with the rotation of the tiltable frame, the horizontal jack 6 adjusts the suspension at the same time The position of the motor 7 of the lifting device keeps the suspension force of the tiltable frame in the vertical direction; the angle pointer 17 is lifted with the tilt of the tiltable frame, when the angle pointer 17 points to the 50° scale on the angle ruler, the horizontal position is stopped synchronously Jack 6, support jack 14, suspension lifting device switch, the angle at which one side of the tilting frame can be lifted is the inclination angle of the rock formation to be simulated 50°;

[0057] The second step is to pave the similar simulation materials of each rock layer in proportion

[0058] 1. Such as figure 2 Shown: choose the front and rear baffles 12 of moderate length and width to install on the inner frame 25, adjust the position of the bolt buckle 28 on the guide rail 27, and fasten with bolts 29, so that the height of the front and rear baffles 12 is equal to the first simulated rock formation The thickness of the similar material to be filled to form the first layer of similar material filling space;

[0059] 2. According to the calculated ratio, weigh the raw materials of the first layer of similar materials required for the experiment, and pour them into a mixer, add water and stir, stir evenly, pour into the first layer of similar materials to fill the space, and scrape it with a scraper , After leveling, compact with wooden boards, sprinkle mica flakes on the surface as a barrier;

[0060] 3. By analogy, until the second layer, the third layer, ..., the similar materials of each layer are filled.

[0061] The third step, hydraulic loading forms a stable similar simulation model

[0062] 1. Such as image 3 Shown: After the pavement similar simulation model is placed for a period of time, start the horizontal jack 6, support jack 14, and the electric switch of the suspension lifting device, and make the pavement similar to the simulation material available at a falling speed of 2mm/s. Tilt the frame slowly to level;

[0063] 2. Start the hydraulic loading device to simulate the ground stress to pressurize the filled similar simulated material;

[0064] 3. Such as Figure 4 As shown, after keeping the load for 2-3 days, remove the front and rear baffles 12 from top to bottom at intervals, and after 2-3 days, remove the remaining front and rear baffles 12 to form a similar simulated material model, hereinafter referred to as model 18;

[0065] The fourth step is to collect images through digital speckle

[0066] 1. Such as Figure 5 As shown, the black paint 19 is sprayed evenly on the surrounding surface of the entire model 18. After the black paint 19 is dried, white paint is sprayed on the black paint 19, so that the white paint will evenly fall on the black paint surface in the form of spots during spraying. Contrast speckle field 20;

[0067] 2. Such as Image 6 As shown, after the paint surface is naturally air-dried, an industrial camera 22 is placed at a certain distance in front of the observation of the model 18, and the industrial camera 22 is connected to the computer 23 through a data cable, and the industrial camera automatic image acquisition software is opened on the computer 23, and then click Tools "Acquisition image" in the column to adjust the image; make the entire rock formation area of ​​the model enter the lens of the industrial camera 22, click "Save Path" in the software toolbar of the computer 23, enter the save path window, select the location where the picture is to be saved, and Set the picture format to bmp and the number of frames to 1 frame/sec. After the setting is completed, click "Continuous Save" in the toolbar to start collecting the original image;

[0068] 3. After collecting the original image, start the hydraulic loading device to pressurize the model. The industrial camera 22 collects and records 20 images of the surface speckle field of the model at different times. After 5-6 days, click "Stop" in the software toolbar of the computer 23 Save" to stop collecting images;

[0069] The fifth step is to perform full-field displacement and strain analysis on the collected images

[0070] Add the original image and the selected series of images collected at the same time interval to the image processing software, compare the changes of the speckle pattern before and after the deformation, and perform a quantitative analysis on the displacement and strain of the whole field to obtain the parameters of the displacement and strain field of model 18 information.