A jointed specimen mold and method of operation thereof

Abstract

The application discloses a kind of filling joint test piece mould and its operating method, it is related to geotechnical engineering technical field.The mould includes bevel cylinder assembly, bevel cylinder assembly includes cylinder bevel, hollow cylinder, fixed ring and base, cylinder bevel and hollow cylinder are connected as a whole by mortise and tenon structure, the outside of the joint of cylinder bevel and hollow cylinder is equipped with fixed ring, the outside of cylinder bevel is slidably connected with base, and the center of the inside of cylinder bevel is provided with air hole.The filling joint test piece with different joint surface inclination angle, joint surface roughness, filling layer thickness and other joint surface parameters can be made by combination and collocation, not only can provide help for the study of the mechanical properties and deformation characteristics of filling joint rock mass, but also save the amount of mould material, realize the efficient use of mould.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of geotechnical engineering, and particularly relates to a filling joint test piece mold and an operating method thereof. BACKGROUND

[0002] Rock mass is a collection of rock and structural plane, and natural rock mass contains a large number of joints. These natural joints are often composed of filling materials such as mud, sand, rock-soil and gravel, which are different from the materials of rock mass. Whether in strength or deformation characteristics, the filling medium and the rock mass material have great differences, which leads to the fact that the engineering properties of rock mass often depend on the properties of these joint planes first. Therefore, the mechanical properties and deformation characteristics of filling joint rock mass have always been a research hotspot in the field of geotechnical engineering. Researchers usually use theoretical analysis, field test, laboratory test and numerical simulation to study the strength and deformation characteristics of filling joint rock mass. Theoretical analysis method can only solve simple joint plane problems. Field test of rock mass mechanics generally costs a lot, and the analysis and test results are not representative. The test results are difficult to popularize and apply. Numerical simulation is greatly affected by parameter setting. Laboratory test is widely used in filling joint related research because of its advantages such as convenient sample preparation, easy operation of instrument, easy control of test parameters and less interference from external factors.

[0003] In natural rock mass, the discontinuity and heterogeneity of rock mass will also cause obvious size effect of rock sample. When the test piece is made, the properties of rock material and the constraints of similarity relationship need to be considered, and suitable rock-like material needs to be selected to make filling joint rock mass test piece. In addition, the joint planes in natural rock mass are often distributed differently. When the joint rock mass sample is made, factors such as joint plane inclination, joint plane roughness and filling layer thickness need to be considered. Therefore, a filling joint test piece mold that can simulate different joint plane distribution parameters is needed. SUMMARY

[0004] The purpose of the present application is to provide a filling joint test piece mold and an operating method thereof to solve the problems in the background art.

[0005] To solve the above technical problems, the present application is realized by the following technical scheme:

[0006] The present application is a filling joint test piece mold, which comprises a bevel cylinder assembly, the bevel cylinder assembly comprises a bevel cylinder, a hollow cylinder, a fixing ring and a base, the bevel cylinder and the hollow cylinder are connected into one body through a mortise and tenon structure, a fixing ring is assembled on the outside of the connection between the bevel cylinder and the hollow cylinder, the base is slidingly connected to the outside of the bevel cylinder, and a gas hole is formed in the center of the inside of the bevel cylinder.

[0007] Further, the fixed ring is internally provided with a tensioning groove at one end, and a screw is arranged inside the fixed ring and corresponds to the tensioning groove.

[0008] Further, the fixed ring is internally provided with a tensioning groove at one end, and a screw is arranged inside the fixed ring and corresponds to the tensioning groove.

[0009] Further, the inclination angle of the cylindrical inclined surface is 0° or 30° or 45° or 60°, the internal shape of the base is complementary to the cylindrical inclined surface, and the inclination angle of the internal base is 0° or 60° or 45° or 30°.

[0010] Further, the top of the square base is provided with a length scale.

[0011] An operating method of a filling joint test piece mold, for any one of the above, the steps are as follows:

[0012] S1, according to the joint surface inclination angle and roughness of the filling joint test piece to be prepared, select a corresponding set of cylindrical inclined surface, hollow cylindrical body and base;

[0013] S2, assemble the cylindrical inclined surface and the hollow cylindrical body into one body, and fix them with a fixed ring at the connection position, and place the fixed cylindrical inclined surface and hollow cylindrical body inclined surface downward in the base;

[0014] S3, make a rock test piece;

[0015] S4, pour the filling joint test piece.

[0016] Further, the rock test piece making method in the S3 step is as follows:

[0017] ①, evenly smear the inside of the fixed cylindrical inclined surface and hollow cylindrical body with vaseline or machine oil;

[0018] ②, configure concrete with rock-like material, pour the rock test piece in the inclined surface cylindrical assembly and vibrate and compact it;

[0019] ③, demold and maintain the test piece under standard environment, specifically, demold the rock test piece after 24h of pouring.

[0020] Further, the pouring of the filling joint test piece is as follows:

[0021] a, Put a pair of rock samples in the semicircular groove of the square base, preliminarily determine the position of the rock samples according to the thickness of the filling layer to be poured, then rotate the cross sections of the two side rock samples, keep the inclined surfaces of the two side rock samples at a distance of the thickness of the filling layer and parallel to each other, adjust the position of the adjustable baffle at both ends of the square base to make the baffle contact with the planes of the two side rock samples and limit the displacement of the rock samples;

[0022] b, Spray the inclined surfaces of the two side samples to keep them wet, and evenly smear the part of the filling layer in contact with the semicircular groove in the square base with vaseline or machine oil;

[0023] c, Configure concrete with rock-like material, pour and vibrate the first layer of joint filling layer to compact it;

[0024] d, Evenly smear the inside of the arc-shaped support with vaseline or machine oil, and install the arc-shaped support;

[0025] e, Pour and vibrate the second layer of joint filling layer to compact it;

[0026] f, Evenly smear the inside of the arc top block with vaseline or machine oil, install the arc top block, and adjust the position of the reserved hole on the arc top block according to the inclination angle of the filling layer to be poured, so that the concrete can be poured into the filling layer from the reserved hole;

[0027] g, Pour concrete into the reserved hole of the arc top block to pour and vibrate the top layer of the filling layer to compact it;

[0028] h, Demold and cure the filling layer in a standard environment.

[0029] Further, for a joint rock mass sample with a complex joint surface, the steps for making are as follows:

[0030] (1) 3D scan the rock joint surface to obtain the occurrence information of the joint surface;

[0031] (2) Calculate the roughness coefficient JRC value of the joint surface:

[0032] (3) Scale the intercepted joint surface to the size of the joint sample in proportion, then adjust it along the inclination direction of the filling joint sample to be made to obtain the occurrence of the joint surface with a certain roughness.

[0033] Further, the steps for calculating the JRC value in step (2) are as follows:

[0034] A, intercept the joint surface range;

[0035] B, divide the joint surface;

[0036] C, calculate the root mean square slope Z2 of each profile according to the formula;

[0037] D. Substitute Z2i of each two-dimensional profile line into the following formula to calculate the roughness coefficient JRCi of the i-th profile line of the joint.

[0038] E. Calculate the weighted average of all two-dimensional profile lines JRCi to obtain the joint roughness coefficient JRC, which reflects the three-dimensional morphology of the joint.

[0039] Furthermore, the formula for the root mean square slope Z² is as follows:

[0040]

[0041] In the formula: yi is the height coordinate of the joint surface profile of sampling point i, l is the number of data points, Δx is the interval of data points, and the subscript i is a natural number;

[0042] The formula for calculating the roughness coefficient JRCi is as follows:

[0043] JRCi=32.69+32.98lgZ2i

[0044] In the formula: Z2i is the root mean square slope of the i-th contour line;

[0045] The formula for calculating the joint roughness coefficient JRC is as follows:

[0046]

[0047] In the formula: w is the total number of two-dimensional profile lines.

[0048] The present invention has the following beneficial effects:

[0049] This invention, through combination and matching, can produce filled joint specimens with different joint surface parameters such as joint surface inclination angle, joint surface roughness, and filling layer thickness. This not only helps in studying the mechanical properties and deformation characteristics of filled joint rock masses, but also saves on mold material usage, achieving efficient mold utilization. It has a simple and effective operation method, and can assist in the production of filled joint specimen molds that can simulate filled joint rock masses composed of different rock properties and filling layer combinations, making it widely applicable. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the inclined cylindrical component of a filling joint specimen mold provided in the first embodiment of the present invention;

[0052] Figure 2 This is a side view of the first embodiment of the present invention;

[0053] Figure 3 This is a schematic diagram of the second embodiment of the present invention;

[0054] Figure 4 This is a side view of the second embodiment of the present invention;

[0055] Figure 5 This is a schematic diagram of the structure of the inclined cylindrical surface with different joint surface parameters according to the present invention;

[0056] Figure 6 This is a schematic diagram of the method flow of the present invention;

[0057] Figure 7 The flowcharts for obtaining the joint surface of the special joint surface form of the present invention and the flowcharts for calculating the joint surface roughness coefficient JRC value are shown.

[0058] The attached diagram lists the components represented by each number as follows:

[0059] 11. Inclined cylindrical surface; 12. Hollow cylinder; 13. Fixing ring; 14. Base; 15. Air hole; 16. Screw; 21. Square base; 22. Arc-shaped bracket; 23. Arc-shaped top block; 24. Adjustable baffle; 25. Length scale; 26. Hole. Detailed Implementation

[0060] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Example 1:

[0062] Please see Figure 1 and Figure 2 As shown, the present invention is a mold for filling joint test specimens.

[0063] In this embodiment, the inner surface shape of the inclined surface 1 of the cylinder is formed by stretching ten Barton standard joint profile lines. Different profile lines are selected according to different joint surface roughness to create joint surfaces with different roughness.

[0064] The system includes a sloping cylinder assembly for casting and producing rock specimens. The sloping cylinder assembly includes a cylindrical sloping surface 11, a hollow cylinder 12, a fixing ring 13, and a base 14. The cylindrical sloping surface 11 and the hollow cylinder 12 are connected as one unit by a mortise and tenon structure. A fixing ring 13 is fitted on the outer side of the connection between the cylindrical sloping surface 11 and the hollow cylinder 12, so that the fixing ring 13 can fix the connection between the cylindrical sloping surface 11 and the hollow cylinder 12 to prevent separation. The base 14 is slidably connected to the outer side of the cylindrical sloping surface 11, so that the fixed cylindrical sloping surface 11 and the hollow cylinder 12 are placed with their inclined surfaces facing downward in the base 14. An air hole 15 is opened at the center of the interior of the cylindrical sloping surface 11.

[0065] Preferably, a tension groove is provided inside one end of the fixing ring 13, and a screw 16 is provided inside the fixing ring 13 at a position corresponding to the tension groove. The size of the tension groove can be reduced by rotating the screw 16, thereby making the fixing ring 13 tighter.

[0066] The inclined cylindrical surface 11 is configured with angles of 0°, 30°, 45°, and 60°. To facilitate specimen casting and curing, a base 14 is provided to complement the inclined cylindrical surface 11. The internal shape of the base 14 is complementary to that of the inclined cylindrical surface 11, and it is also configured with angles of 0°, 60°, 45°, and 30°. The fixed inclined cylindrical surface 11 and the hollow cylinder 12 are placed face down in the base 14. Furthermore, because the specimen has a large longitudinal dimension and a small diameter, traditional hammering methods can easily damage the specimen during demolding after concrete curing. Therefore, during demolding, a concrete demolding air pump should be used to inject air into the pre-reserved air holes 15 on the inclined cylindrical surface 11 to allow the concrete specimen to detach from the mold.

[0067] Considering the diverse shapes of joint surfaces in natural rock masses, the inner shape of the joint surface is formed by stretching ten standard joint surface curves. The inner sides of the cylindrical inclined surface 11 are set into different shapes to simulate the roughness of different joint surfaces in natural rock masses. Furthermore, the joint filling layer is simplified to a filling layer with parallel joint surfaces on both sides and equal thickness. Therefore, when setting the cylindrical inclined surface 11, two should be set as a group, and their inner cross sections should be complementary.

[0068] In use, the cylindrical inclined surface 11 is installed on the top of the hollow cylinder 12 through a tenon and mortise connection. Then, the fixing ring 13 is slidably connected to the outside of the cylindrical inclined surface 11 and slid to the connection between the cylindrical inclined surface 11 and the hollow cylinder 12. Then, the screw 16 is rotated so that the rotation of the screw 16 can adjust the width of the tension groove on the inner side of the fixing ring 13. In turn, the size of the tension groove is reduced by rotating the screw 16, so that the fixing ring 13 is tightened. This allows the fixing ring 13 to fix the connection between the cylindrical inclined surface 11 and the hollow cylinder 12 and prevent it from detaching. Then, the fixed cylindrical inclined surface 11 and the hollow cylinder 12 are placed with their inclined surfaces facing down in the base 14.

[0069] Simultaneously, during use, the inclined surface 11 of the cylinder can be set to any one of the angles: 0°, 30°, 45°, or 60°. Then, the angle inside the base 14, which is assembled with the inclined surface 11 of the cylinder, is designed to complement the inclined surface 11 of the cylinder. That is, the angle inside the base 14 can be any one of 0°, 60°, 45°, or 30°. Thus, when the angle of the inclined surface 11 of the cylinder is 0°, the angle inside the base 14 is 0°; when the angle of the inclined surface 11 of the cylinder is 30°, the angle inside the base 14 is 60°; when the angle of the inclined surface 11 of the cylinder is 45°, the angle inside the base 14 is 45°; and when the angle of the inclined surface 11 of the cylinder is 60°, the angle inside the base 14 is 30°. This ensures that the fixed inclined surface 11 of the cylinder and the hollow cylinder 12 are placed with their inclined surfaces facing downwards in the base 14. In addition, since the specimen has a large longitudinal dimension and a small diameter, the traditional hammering method is likely to damage the specimen when demolding after the concrete curing is completed. Therefore, when demolding the specimen, a concrete demolding air pump should be used to inject air into the air hole 15 reserved on the inclined surface 11 of the cylinder to make the concrete rock specimen detach from the mold.

[0070] Example 2:

[0071] refer to Figure 4 and Figure 5 The difference from Example 1 is:

[0072] In this embodiment, the inner surface shape of the inclined surface 1 of the cylinder is formed by stretching ten Barton standard joint profile lines. Different profile lines are selected according to different joint surface roughness to create joint surfaces with different roughness.

[0073] It also includes a support, and the rock specimen produced by the inclined cylindrical component is placed inside the support after curing. The support includes a square base 21, an arc-shaped bracket 22 and an arc-shaped top block 23. The two ends of the top of the square base 21 are slidably connected to the arc-shaped bracket 22, and the top of the two arc-shaped brackets 22 are slidably connected to the top of the arc-shaped brackets 22, so that the square base 21, the arc-shaped bracket 22 and the arc-shaped top block 23 can be connected by a mortise and tenon structure. The top of the square base 21 has a semi-cylindrical groove, and the semi-cylindrical groove is clearance-fitted with the rock specimen produced by the inclined cylindrical component. The two ends of the semi-cylindrical groove are provided with adjustable baffles 24. The top of the square base 21 is provided with a length scale 25, and the arc-shaped top block 23 has a hole 26 inside.

[0074] In use, the square base 21 has grooves on both sides of its long side for fixing the arc-shaped bracket 22. The grooves start from the short side and are three-quarters the length of the long side. Adjustable baffles 24 are provided on both sides of the long side of the square base 21. These baffles 24 can be moved by rotating screws and can be moved along the axis to any position in the groove, thus fixing the position of the rock specimen. The arc-shaped bracket 22 consists of two pieces, each half the length of the long side of the square base 21. The arc-shaped bracket 22 is fixed by inserting the protrusion at the bottom of the arc-shaped bracket 22 into the groove of the square base 21. The installed arc-shaped bracket 22 should be in the middle of the square base 21, with one end of the arc-shaped bracket 22 tightly against the end of the groove. A hole 26 is provided at the center of the arc-shaped top block 23 to facilitate the pouring of the filling layer. The contact surface between the arc-shaped bracket 22 and the arc-shaped top block 23 is smooth and can be moved along the contact surface. By moving the arc-shaped top block 23 and adjusting the position of the hole 26, filling layers with different inclination angles can be poured.

[0075] The cylindrical inclined surface 11 is installed on the top of the hollow cylinder 12 through a tenon and mortise connection. Then, the fixing ring 13 is slidably connected to the outside of the cylindrical inclined surface 11 and slid to the connection between the cylindrical inclined surface 11 and the hollow cylinder 12. Then, the screw 16 is rotated so that the width of the tension groove inside the fixing ring 13 can be adjusted. The size of the tension groove is reduced by rotating the screw 16, so that the fixing ring 13 is tightened. The fixing ring 13 can fix the connection between the cylindrical inclined surface 11 and the hollow cylinder 12 to prevent separation. Then, the fixed cylindrical inclined surface 11 and the hollow cylinder 12 are placed with their inclined surfaces facing down in the base 14. When demolding the specimen, a concrete demolding air pump should be used to inject air into the air hole 15 reserved on the cylindrical inclined surface 11 to make the concrete specimen detach from the mold.

[0076] After the rock specimens have been cast and cured, a pair of rock specimens are placed in the semi-cylindrical groove of the square base 21, ensuring that the joint surfaces of the two specimens correspond and leaving space equal to the joint thickness. Based on the planned filling layer thickness, and referring to the length scale 25 on the top of the square base 21, the initial position of the rock specimens is determined. Then, the cross-sections of the two rock specimens are rotated to ensure that the inclined surfaces of the two rock specimens maintain the distance of the filling layer thickness and are parallel to each other. Finally, the positions of the adjustable baffles 24 at both ends of the square base 21 are adjusted so that the baffles contact the planes of the two rock specimens, restricting the displacement of the rock specimens. After the rock specimens are fixed, the filling layer is cast into the gap between the two rock specimens, and the joint layer is then cast.

[0077] In another embodiment, the adjustable baffle 24 is composed of a bolt and a circular plate. The outer side of the bolt is threaded to the square base 21. The circular plate is fixed to one end of the bolt inside the semi-cylindrical groove, so that the circular plate can be moved by rotating the bolt.

[0078] The mold for filling joint specimens in this embodiment can control the thickness of the filling layer, the dip angle of the joint surface, and the roughness of the jointed rock mass specimen, thereby producing filling joint specimens with different joint surface parameters.

[0079] See Figure 2 As shown, the filling layer is poured on the support. First, after the rock specimens have been poured and cured, a pair of rock specimens are placed in the semi-cylindrical groove of the square base 21. Based on the planned filling layer thickness, the position of the rock specimens is initially determined by referring to the length scale 25 on the top of the square base 21. Then, the cross-sections of the two rock specimens are rotated to ensure that the inclined surfaces of the two rock specimens maintain the distance of the filling layer thickness and are parallel to each other. Finally, the positions of the adjustable baffles 24 at both ends of the square base 21 are adjusted so that the baffles contact the planes of the two rock specimens, restricting the displacement of the rock specimens. After the rock specimens are fixed, the filling layer is poured into the gap between the two rock specimens.

[0080] Both the inclined cylindrical surface 11 and the hollow cylindrical body 12 are integrally formed and connected by a mortise and tenon structure with a serrated mortise and tenon joint. The mortise and tenon joint is secured with a retaining ring 13. During installation, tightening the screw 16 of the retaining ring 13 causes it to retract, thus securing the inclined cylindrical surface 11 and the hollow cylindrical body 12. The square base 21 has grooves along its long side for fixing the arc-shaped support 22. The grooves begin from the short side and are three-quarters the length of the long side. Adjustable baffles 24 are provided on both sides of the long side of the square base 21. These baffles can be moved by rotating screws, allowing them to be moved along the axial direction to any position within the grooves, thereby fixing the rock specimen. The arc-shaped support 22 consists of two pieces, each half the length of the long side of the square base 21. The arc-shaped support 22 is secured by inserting the protrusion at its bottom into the groove of the square base 21. The installed arc-shaped support 22 should be positioned in the middle of the square base 21, with one end of the arc-shaped support tightly against the end of the groove. A hole 26 is provided at the center of the arc-shaped block 23 to facilitate the pouring of the filling layer; the arc-shaped support 22 has a smooth contact surface with the arc-shaped block 23 and can be moved along the contact surface. By moving the arc-shaped block 23 and adjusting the position of the hole 26, filling layers with different inclination angles can be poured.

[0081] Example 3:

[0082] Please refer to Figure 5 and Figure 7 The difference from Example 1 is:

[0083] In this embodiment, the inner surface shape of the inclined surface 1 of the cylinder is formed by stretching ten Barton standard joint profile lines. Different profile lines are selected according to different joint surface roughness to create joint surfaces with different roughness.

[0084] The cylindrical inclined surface 11 is formed by casting. The inner surface shape of the cylindrical inclined surface 11 is formed by stretching the Barton standard joint profile line. When stretching the joint profile line, the joint profile line is first scaled proportionally to the size of the joint specimen, and then stretched along the inclination direction of the joint specimen to be filled, so as to obtain the joint surface orientation of a certain joint surface roughness.

[0085] To prepare jointed rock mass specimens with unique joint surface patterns, 3D scanning modeling can be used to determine the joint surface information. Based on the joint surface occurrence information, the joint surface roughness coefficient (JRC) value can be calculated, thereby producing infill joint specimens with complex joint surface patterns. The specific steps are as follows:

[0086] (1) Perform 3D scanning on the rock joint cross-section to obtain information on the attitude of the joint surface;

[0087] (2) Calculate the joint surface roughness coefficient JRC value:

[0088] A. Select the joint surface range: Select a suitable joint surface from the entire scanned section;

[0089] B. Divide the joint surfaces, as shown in the following form. Figure 4 As shown;

[0090] Calculate the root mean square slope Z2 of each profile line according to the formula:

[0091]

[0092] In the formula: yi is the height coordinate of the joint surface profile of sampling point i, l is the number of data points, Δx is the interval of data points, and the subscript i is a natural number;

[0093] D. Substitute Z2i of each two-dimensional profile line into the following formula to calculate the roughness coefficient JRCi of the i-th profile line of the joint:

[0094] JRCi=32.69+32.98lgZ2i

[0095] In the formula: Z2i is the root mean square slope of the i-th contour line;

[0096] E. Calculate the weighted average of JRCi for all two-dimensional profile lines to obtain the joint roughness coefficient JRC, which reflects the three-dimensional morphology of the joint:

[0097]

[0098] In the formula: w is the total number of two-dimensional profile lines;

[0099] (3) Scale the cut joint surface proportionally to the size of the joint specimen, and then adjust it along the inclination direction of the joint specimen to be filled, so as to obtain the joint surface orientation of a certain joint surface roughness.

[0100] Example 4:

[0101] Please refer to Figure 6 Based on the above embodiments one and two, the operation method is disclosed.

[0102] This embodiment is applied to naturally formed rough joint surfaces.

[0103] Includes the following steps:

[0104] S1. Based on the joint surface inclination angle and roughness of the joint sample to be filled, select a set of cylindrical inclined surfaces 11, hollow cylinders 12 and bases 14. For example, first select a cylindrical inclined surface 11 with a diameter of 5 cm, a joint surface inclination angle of 30° and a joint surface roughness coefficient JRC = 10, then select a hollow cylinder 12 with a diameter of 5 cm and a length of 5 cm, and finally select a base 14 with a corresponding inclination angle of 60°.

[0105] S2. Assemble the inclined cylindrical surface 11 and the hollow cylindrical body 12 into one piece. The connection between the two is fixed with a retaining ring 13. Specifically, tighten the screw 16 inside the retaining ring 13 to shrink the retaining ring 13, thereby fixing the inclined cylindrical surface 11 and the hollow cylindrical body 12. After fixing, the inclined cylindrical surface 11 and the hollow cylindrical body 12 are placed with their inclined surfaces facing down in the base 14.

[0106] S3. Prepare rock specimens:

[0107] ① Apply petroleum jelly or machine oil evenly to the fixed inclined surface 11 of the cylinder and the inside of the hollow cylinder 12;

[0108] ② Concrete is prepared using rock-like materials. Rock specimens are poured into the inclined cylindrical component 1 and compacted by vibration. For example, fine sandstone is simulated based on the principle of similarity. The rock-like materials are made by mixing cement, quartz sand, water and admixtures. The specific material ratio (mass ratio) is cement: quartz sand: tap water: water-reducing agent: retarder = 10:30:5:0.02:0.01. The cement is 32.5 ordinary Portland cement, the quartz sand is medium sand with a particle size of 0.16-5mm, the water is laboratory tap water, the water-reducing agent is polycarboxylate water-reducing agent, and the retarder is high-purity sodium gluconate.

[0109] ③ Demolding and curing of the specimens under standard conditions: Specifically, the rock specimens are demolded 24 hours after being poured. During demolding, a concrete demolding air pump is used to inject air into the air holes 15 reserved on the inclined surface 11 of the cylinder to remove the concrete specimens from the mold. Then, the specimens are placed in a standard concrete curing room for curing for 28 days.

[0110] In use, apply petroleum jelly or machine oil evenly to the fixed cylindrical inclined surface 11 and the inside of the hollow cylinder 12. Then, install the cylindrical inclined surface 11 at the top of the hollow cylinder 12 using a tenon and mortise connection. Next, slide the retaining ring 13 onto the outside of the cylindrical inclined surface 11 through a sliding connection, and then slide it to the connection point between the cylindrical inclined surface 11 and the hollow cylinder 12. Then, rotate the screw 16 so that the rotation of the screw 16 can adjust the width of the tension groove on the inner side of the retaining ring 13, thereby reducing the tension. The size of the tension groove is adjusted to tighten the fixing ring 13, thereby fixing the connection between the cylindrical inclined surface 11 and the hollow cylinder 12 and preventing separation. Then, concrete is injected into the interior of the cylindrical inclined surface 11 and the hollow cylinder 12. The fixed cylindrical inclined surface 11 and the hollow cylinder 12 are then placed with their inclined surfaces facing down in the base 14. When demolding the specimen, a concrete demolding air pump is used to inject air into the air hole 15 reserved in the cylindrical inclined surface 11 to make the concrete specimen detach from the mold.

[0111] Simultaneously, during use, the inclined surface 11 of the cylinder can be set to any one of the angles: 0°, 30°, 45°, or 60°. Then, the angle inside the base 14, which is assembled with the inclined surface 11 of the cylinder, is designed to complement the inclined surface 11 of the cylinder. That is, the angle inside the base 14 can be any one of 0°, 60°, 45°, or 30°. Thus, when the angle of the inclined surface 11 of the cylinder is 0°, the angle inside the base 14 is 0°; when the angle of the inclined surface 11 of the cylinder is 30°, the angle inside the base 14 is 60°; when the angle of the inclined surface 11 of the cylinder is 45°, the angle inside the base 14 is 45°; and when the angle of the inclined surface 11 of the cylinder is 60°, the angle inside the base 14 is 30°. This ensures that the fixed inclined surface 11 of the cylinder and the hollow cylinder 12 are placed with their inclined surfaces facing downwards in the base 14. In addition, since the specimen has a large longitudinal dimension and a small diameter, the traditional hammering method is likely to damage the specimen when demolding after the concrete curing is completed. Therefore, when demolding the specimen, a concrete demolding air pump should be used to inject air into the air hole 15 reserved on the inclined surface 11 of the cylinder to make the concrete specimen detach from the mold.

[0112] S4. Casting and filling joint specimens:

[0113] a. Place a pair of rock specimens in the semi-cylindrical groove of the square base 21. Based on the thickness of the planned filling layer, refer to the length scale 25 on the top of the square base 21 to initially determine the position of the rock specimens. Then, rotate the cross-sections of the two rock specimens to ensure that the inclined surfaces of the two rock specimens are parallel to each other while maintaining the distance of the filling layer thickness. Finally, adjust the position of the adjustable baffles 24 at both ends of the square base 21 so that the baffles contact the planes of the two rock specimens, restricting the displacement of the rock specimens.

[0114] b. Spray the inclined surfaces of the specimens on both sides to keep them moist, and apply petroleum jelly or machine oil evenly to the part of the filling layer that contacts the semi-cylindrical groove in the square base 21.

[0115] c. Use rock-like materials to prepare concrete, pour the first joint filling layer and vibrate it to make it dense. For example, use gypsum, which is stable and low in cost, as a similar material. The specific mix ratio (mass ratio) is water:gypsum = 1:3.

[0116] d. Apply petroleum jelly or machine oil evenly to the inside of the arc-shaped bracket 22 and install the arc-shaped bracket 22;

[0117] e. Pour the second joint filling layer and compact it with vibration;

[0118] f. Apply petroleum jelly or machine oil evenly to the inside of the arc top block 23, and install the arc top block 23. During installation, adjust the position of the reserved hole 26 on the arc top block 23 according to the inclination angle of the filling layer to be poured, so that concrete can be injected into the filling layer from the reserved hole 26.

[0119] g. Inject concrete into the top layer of the filling layer through the reserved hole 26 in the arc-top block 23 and compact it.

[0120] h. Demolding and curing of the filling layer under standard conditions: Specifically, demolding is carried out 24 hours after the filling layer is poured. During demolding, the arc top block 23 is removed first, then the two arc-shaped supports 22 are removed, and finally the filling joint specimen is removed from the mold. Then it is placed in a standard concrete curing room for curing for 28 days.

[0121] First, after the rock specimens inside the inclined cylindrical assembly have been cast and cured, a pair of rock specimens are placed in the semi-cylindrical groove of the square base 21. Based on the planned thickness of the filling layer, and referring to the length scale 25 on the top of the square base 21, the initial position of the rock specimens is determined. Then, the cross-sections of the two rock specimens are rotated to ensure that the inclined surfaces of the two rock specimens maintain the distance of the filling layer thickness and are parallel to each other. Finally, the positions of the adjustable baffles 24 at both ends of the square base 21 are adjusted so that the baffles contact the planes of the two rock specimens, restricting the displacement of the rock specimens. After the rock specimens are fixed, the filling layer is cast into the gap between the two rock specimens.

[0122] The square base 21 has grooves on both sides of its long side for fixing the arc-shaped bracket 22. The grooves start from the short side and are three-quarters the length of the long side. The square base 21 has adjustable baffles 24 on both sides of its long side. The adjustable baffles 24 can be moved by rotating screws. The baffles can be moved to any position in the groove along the axial direction, thereby fixing the position of the rock specimen.

[0123] Apply petroleum jelly or machine oil evenly to the inner sides of the arc-shaped bracket 22 and the arc-shaped top block 23. The arc-shaped bracket 22 consists of two pieces, each half the length of the long side of the square base 21. The arc-shaped bracket 22 is fixed by inserting the protrusion at the bottom of the arc-shaped bracket 22 into the groove opened in the square base 21. The installed arc-shaped bracket 22 should be in the middle of the square base 21, with one end of the arc-shaped bracket 22 tightly against the end of the groove. Then, pour the first layer of joint filling and vibrate it to compact it. Then, assemble the arc-shaped top block 23 between the tops of the two arc-shaped brackets 22, pour the second layer of joint filling and vibrate it to compact it. At the same time, a hole 26 is opened in the center of the arc-shaped top block 23 to facilitate the pouring of the filling layer. The contact surface between the arc-shaped bracket 22 and the arc-shaped top block 23 is smooth and can be moved along the contact surface. By moving the arc-shaped top block 23 and adjusting the position of the hole 26, filling layers with different inclination angles can be poured.

[0124] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0125] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A j ointed specimen mold for filling, characterized by: The utility model provides a kind of rock joint filling test device, including inclined plane cylinder assembly, the inclined plane cylinder assembly includes cylinder inclined plane (11), hollow cylinder (12), fixed ring (13) and base (14), the cylinder inclined plane (11) and hollow cylinder (12) are connected as a whole by mortise and tenon structure, the outside of the junction of cylinder inclined plane (11) and hollow cylinder (12) is equipped with fixed ring (13), the outside of cylinder inclined plane (11) is slidably connected with base (14), the center of the inside of cylinder inclined plane (11) is equipped with air hole (15); It also includes a support, the support includes a square base (21), an arc-shaped bracket (22) and an arc top block (23), both ends of the top of the square base (21) are slidably connected with the arc-shaped bracket (22), the arc top block (23) is slidably connected between the top ends of the two arc-shaped brackets (22), a semicylindrical recess is formed in the top end of the square base (21), adjustable baffles (24) are arranged in the semicylindrical recess at both ends, a hole (26) is formed in the arc top block (23), in this way, when pouring and filling joint specimens, a, a pair of rock specimens are placed in the semicylindrical recess of the square base (21), the positions of the rock specimens are preliminarily determined according to the thickness of the filling layer to be poured; then, the cross sections of the two rock specimens are rotated, the inclined planes of the two rock specimens are kept at a distance of the thickness of the filling layer and are parallel to each other, the positions of the adjustable baffles (24) at both ends of the square base (21) are adjusted, the baffles are in contact with the planes of the two rock specimens, and the displacement of the rock specimens is limited; b, the inclined planes of the two rock specimens are sprayed to keep the inclined planes wet, and vaseline or machine oil is uniformly applied to the contact part of the filling layer and the semicylindrical recess in the square base (21); c, a rock-like material is used to configure concrete, the first layer of joint filling layer is poured and vibrated to be compacted; d, the inside of the arc-shaped bracket (22) is uniformly smeared with vaseline or machine oil, and the arc-shaped bracket (22) is installed; e, the second layer of joint filling layer is poured and vibrated to be compacted; f, the inside of the arc top block (23) is uniformly smeared with vaseline or machine oil, and the arc top block (23) is installed, the position of the reserved hole (26) on the arc top block (23) is adjusted according to the inclination angle of the filling layer to be poured, so that the concrete can be injected into the filling layer from the reserved hole (26); g, the concrete is injected from the reserved hole (26) of the arc top block (23) to pour and compact the top layer of the filling layer; h, the filling layer is demolded and cured in a standard environment; The inclination angle of the cylinder inclined plane (11) is 0°, 30°, 45° or 60°, the inside of the base (14) is complementary to the cylinder inclined plane (11), the inclination angle of the inside of the base (14) is 0°, 60°, 45° or 30°, and a length scale (25) is arranged on the top of the square base (21); The shape of the inner surface of the cylinder inclined plane (11) is stretched by Barton standard joint profile lines; different profile lines are selected according to different joint surface roughness to produce joint surfaces with different roughness.

2. A j ointed specimen mold according to claim 1, wherein The inside of one end of the fixed ring (13) is provided with a tensioning groove, and the inside of the fixed ring (13) and the position corresponding to the tensioning groove are provided with a screw (16).

3. A method of operating a jointed specimen moulding apparatus as claimed in claim 1 or claim 2, characterised in that, The steps are as follows: S1, according to the inclination angle and roughness of the joint surface of the prepared filling joint sample, a group of corresponding cylindrical inclined surface (11), hollow cylinder (12) and base (14) are selected; S2, the cylindrical inclined surface (11) and the hollow cylinder (12) are assembled into one, the connection place is fixed with the fixed ring (13), the fixed cylindrical inclined surface (11) and the hollow cylinder (12) are placed in the base (14) with the inclined surface downward; S3, the rock sample is prepared; S4, the filling joint sample is poured.

4. A method of operating a mold for filling a jointed specimen according to claim 3, wherein, The rock sample preparation method in the S3 step is as follows: ①, evenly smear the inside of the fixed cylindrical inclined surface (11) and the hollow cylinder (12) with vaseline or oil; ②, configure concrete with rock-like material, pour and vibrate the rock sample in the inclined surface cylinder assembly (1) to compact it; ③, demold and maintain the sample in the standard environment, specifically, demold the rock sample after pouring for 24 hours.

5. A method of operating a mold for filling a jointed specimen according to claim 3, wherein, The pouring filling joint sample has the following steps: a, take a pair of rock samples and place them in the semicylindrical groove of the square base (21), preliminarily determine the position of the rock sample according to the thickness of the filling layer to be poured, then rotate the cross sections of the two rock samples to keep the inclined surfaces of the two rock samples at a distance of the thickness of the filling layer and parallel to each other, adjust the positions of the adjustable baffles (24) at both ends of the square base (21) to make the baffles contact with the planes of the two rock samples and limit the displacement of the rock samples; b, spray the inclined surfaces of the two rock samples to keep them wet, and evenly smear the part of the semicylindrical groove in the square base (21) that contacts with the filling layer with vaseline or oil; c, configure concrete with rock-like material, pour and vibrate the first layer of joint filling layer to compact it; d, evenly smear the inside of the arc-shaped support (22) with vaseline or oil, and install the arc-shaped support (22); e, pour and vibrate the second layer of joint filling layer to compact it; f, evenly smear the inside of the arc top block (23) with vaseline or oil, and install the arc top block (23), during the installation, adjust the position of the reserved hole (26) on the arc top block (23) according to the inclination angle of the filling layer to be poured, so that the concrete can be injected into the filling layer from the reserved hole (26); g, inject the concrete from the reserved hole (26) of the arc top block (23) to pour and vibrate the top layer of the filling layer to compact it; h, demold and maintain the filling layer in the standard environment.

6. A method of operating a mold for filling a jointed specimen according to claim 3, wherein, The steps of preparing the joint rock mass sample with complex joint surface are as follows:

1. Perform 3D scanning on the rock joint surface to obtain the occurrence information of the joint surface; 2. Calculate the roughness coefficient JRC value of the joint surface:

3. Scale the intercepted joint surface to the size of the joint sample in proportion, and then adjust it along the inclination direction of the prepared filling joint sample to obtain the occurrence of the joint surface with a certain roughness.

7. A method of operating a mold for filling a jointed specimen according to claim 6, wherein, The steps of calculating the JRC value in step 2 are as follows: A, intercept the joint surface range; B, divide the joint surface; C. Calculate the slope root mean square of each profile line according to the formula ; D. Calculate the roughness coefficient JRCi of the i-th profile line of joint by substituting Z2i of each two-dimensional profile line into the following formula; E. Calculate the weighted average value of all two-dimensional profile line JRCi to obtain the joint roughness coefficient JRC which can reflect the three-dimensional morphology of joint; Root Mean Square Slope The formula is as follows: wherein: yi is the joint surface profile height coordinate of the sampling point i, I is the number of data points, is the interval of data points, and subscript i is a natural number; The calculation formula of the roughness coefficient JRCi is as follows: wherein: RMS slope of the ith profile line; The calculation formula of the joint roughness coefficient JRC is as follows: In the formula, w is the total number of two-dimensional profile lines.

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