Die for preparing hollow cylindrical torsional shear sample of non-through fractured rock mass

Abstract

The utility model discloses a non-through fractured rock mass hollow cylinder torsional shear sample preparation mold which comprises a bottom plate, an outer side panel, an inner side panel and a middle support are sequentially and movably connected to the bottom plate from outside to inside, and a gap is formed between the outer side panel and the inner side panel; the inner side panel is sleeved with an insertion piece, the outer edge of the insertion piece is located in the gap, and the inner edge is inserted into the middle support. The assembling process of the mold is simplified, and the consumption of manpower and materials in the preparation process of the fractured rock mass hollow cylinder torsional shear sample is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of molds and relates to a mold for preparing a hollow cylindrical torsion shear specimen of a non-through fractured rock mass. Background Art

[0002] The excavation process of underground caverns not only involves changes in stress magnitude, but also rotation of the stress principal axis direction. Compared with the traditional triaxial test, the hollow cylinder torsion shear test can apply torque while applying confining pressure, realizing the study of rock stress state under the dual variable conditions of "confining pressure-stress principal axis", and thus gradually becoming a new research hotspot in geotechnical engineering. Due to the limitations of sample preparation methods, the previous hollow cylinder torsion shear tests were mostly conducted on intact rocks. The preparation of hollow cylinder torsion shear test specimens requires first making a cylindrical rock specimen with a diameter of 50 mm and a height of 110 mm, and then drilling a hole in the cylindrical specimen to form a hollow cylinder specimen with an inner diameter of 30 mm and an outer diameter of 50 mm. This sample preparation method makes it difficult to consider the influence of cracks, the most important factor affecting the mechanical properties of rock mass, on the results of the hollow cylinder torsion shear test. Utility Model Content

[0003] The utility model aims to provide a preparation die for a hollow cylindrical torsion shear specimen of a non-through fissure rock mass, thereby solving the technical problem that it is difficult to consider the fissures in the prior art.

[0004] The technical scheme adopted by the utility model is a mold for preparing a hollow cylindrical torsional shear specimen of a non-through fractured rock mass, comprising a bottom plate, on which an outer panel, an inner panel and a middle support are movably connected in sequence from the outside to the inside, and a gap is formed between the outer panel and the inner panel; an insert is sleeved on the inner panel, the outer edge of the insert is located in the gap, and the inner edge is inserted into the middle support.

[0005] The utility model is also characterized in that:

[0006] A groove is provided on the outer side wall of the middle support, and the inner edge of the insert is located in the groove.

[0007] The outer panel comprises two outer plates, which are spliced ​​into a hollow cylinder and connected by a connecting piece.

[0008] The inner panel comprises four inner panels, which are spliced ​​into a hollow cylinder; cracks are opened along the radial direction of the hollow cylinder, and the inserts are located in the cracks.

[0009] The bottom plate is provided with a first groove and a second groove, the inner panel and the middle support bottom are located in the first groove, and the outer panel bottom is located in the second groove.

[0010] The beneficial effects of the utility model are as follows: the utility model is a mold for preparing hollow cylindrical torsional shear specimens of rock mass with non-through cracks, which takes the factor of cracks into consideration during the sample preparation process, thereby realizing the transformation of preparing hollow cylindrical torsional shear specimens of rock mass to preparing hollow cylindrical torsional shear specimens of rock mass, and facilitating the subsequent quantitative study on the influence of cracks on the test results of hollow cylinder torsional shear; the middle support is used as the support for the inner panel, the panel cracks are arranged in sections, and the insertion of the cracks is ensured by slotting the side wall of the middle support; the outer panel is connected in the form of a clamp, which simplifies the style of the mold and optimizes the operability of the sample preparation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of a mold for preparing a hollow cylindrical torsional shear specimen of a non-through fractured rock mass according to the utility model;

[0012] Figure 2 This is a front view of the outer side plate of a mold for preparing a hollow cylindrical torsion shear specimen of a non-through fractured rock mass according to the utility model;

[0013] Figure 3 It is a top view of the outer side plate of the mold for preparing the hollow cylindrical torsion shear specimen of non-through fractured rock mass of the utility model;

[0014] Figure 4 This is a front view of the inner side plate of the mold for preparing a hollow cylindrical torsion shear specimen of a non-through fractured rock mass according to the utility model;

[0015] Figure 5 It is a top view of the inner side plate of the mold for preparing the hollow cylindrical torsion shear specimen of non-through fractured rock mass of the utility model;

[0016] Figure 6 The utility model is a top view of the inner bottom plate of a mold for preparing a hollow cylindrical torsional shear specimen of a non-through fractured rock mass.

[0017] In the figure, 1. bottom plate, 2. outer panel, 3. inner panel, 4. middle support, 5. insert, 6. crack, 7. first groove, 8. second groove. DETAILED DESCRIPTION

[0018] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.

[0019] Example 1

[0020] Preparation mold for hollow cylindrical torsion shear specimen of non-through fractured rock mass, such as Figure 1 As shown, it includes a base plate 1, on which an outer panel 2, an inner panel 3, and a middle support 4 are movably connected in sequence from the outside to the inside, and a gap is formed between the outer panel 2 and the inner panel 3; an insert 5 is sleeved on the inner panel 3, the outer edge of the insert 5 is located in the gap, and the inner edge is inserted into the middle support 4.

[0021] Example 2

[0022] A mold for preparing hollow cylindrical torsional shear specimens of non-through fractured rock mass comprises a bottom plate 1, on which an outer panel 2, an inner panel 3 and a middle support 4 are movably connected in sequence from the outside to the inside, and a gap is formed between the outer panel 2 and the inner panel 3; an insert 5 is sleeved on the inner panel 3, the outer edge of the insert 5 is located in the gap, and the inner edge is inserted into the middle support 4.

[0023] like Figure 2 , Figure 3 As shown, the outer panel 2 includes two outer panels 201, which are spliced ​​into a hollow cylinder and connected by a connector. Figure 4 , Figure 5 As shown, the inner panel 3 includes four inner panels 301, which are spliced ​​into a hollow cylinder; a crack 6 is opened along the radial direction of the hollow cylinder, and the insert 5 is located in the crack 6. Figure 6 As shown, a first groove 7 and a second groove 8 are formed on the bottom plate 1 , the bottom of the inner panel 3 and the middle support 4 are located in the first groove 7 , and the bottom of the outer panel 2 is located in the second groove 8 .

[0024] Example 3

[0025] The mold for preparing hollow cylindrical torsion shear specimens of non-through fractured rock mass comprises a bottom plate 1, on which an outer panel 2, an inner panel 3, and an intermediate support 4 are movably connected in sequence from outside to inside, and a gap is formed between the outer panel 2 and the inner panel 3; a metal insert 5 is sleeved on the inner panel 3, the outer edge of the insert 5 is located in the gap, and the inner edge is inserted into the intermediate support 4. Specifically, a groove matching the insert 5 is opened on the outer wall of the intermediate support 4, and the insert 5 is located in the groove.

[0026] The outer panel 2 includes two outer panels 201, which are spliced ​​into a hollow cylinder and fixed by an annular clamp. In this embodiment, the hollow cylinder is an organic glass cylinder with an inner diameter of 50 mm, an outer diameter of 60 mm, a height of 120 mm, and a thickness of 5 mm.

[0027] The inner panel 3 includes four inner panels 301, which are spliced ​​into a hollow cylinder; a crack 6 is opened radially along the hollow cylinder, and the insert 5 is located in the crack 6. Each inner panel 301 is divided into two upper and lower sections by the crack 6. In this embodiment, the hollow cylinder is a plexiglass cylinder with an inner diameter of 20 mm, an outer diameter of 30 mm, a height of 120 mm, and a wall thickness of 5 mm.

[0028] The bottom plate 1 is provided with a first groove 7 and a second groove 8, the bottom of the inner panel 3 and the middle support 4 are located in the first groove 7, and the bottom of the outer panel 2 is located in the second groove 8. In this embodiment, the bottom plate is a square organic glass plate with a side length of 100 mm and a thickness of 15 mm, and the depth of the first groove 7 and the second groove 8 is 10 mm.

[0029] The use method of the utility model for preparing the hollow cylindrical torsional shear specimen of non-through fractured rock mass is as follows:

[0030] Step 1: Apply vaseline oil on the inner surface of the outer panel 2, the inner and outer surfaces of the inner panel 3, the inner wall of the first groove 7 and the second groove 8, and the surface of the metal insert 5 to facilitate assembly and later demoulding;

[0031] Step 2: After assembling the middle support 4 and the four sections of the inner side plate 301 below the crack 6, insert the whole into the first groove 7;

[0032] Step 3, insert the two outer plates 201 into the second groove 8, and clamp them with a clamp to make them into a whole;

[0033] Step 4: Place the metal insert 5 on the lower inner panel 301, and make the inner edge of the metal insert 5 in the groove of the middle support 4; lower the upper inner panel 301 along the outer wall of the middle support 4 to the metal insert 5, and complete the assembly of the mold. Since vaseline oil is applied to the surface of the inner panel 3 in advance, the upper inner panel 301 can be adsorbed on the surface of the middle support 4;

[0034] Step 5: Pour the prepared cement mortar between the outer panel 2 and the inner panel 3 from the top of the mold, and vibrate to ensure compaction;

[0035] Step 6: Place the mold in a standard curing box and cure it for 24 hours, then take it out, remove the embedded metal insert 5, and continue to place it in the curing box for curing for 3 days;

[0036] Step 7: Take out the sample after curing for 3 days and demould it; when demoulding, remove them in the order of "bottom plate 1 → middle support 4 → inner panel 3 → outer panel 2".

[0037] The demoulded specimen is placed in a standard curing box for 28 days and then taken out. The upper and lower surfaces of the specimen are polished smooth using a grinder. The final specimen is a hollow cylindrical specimen with an inner diameter of 30 mm, an outer diameter of 50 mm, and a height of 110 mm ± 2 mm and a non-through crack of a specific length and inclination.

Claims

1. A mold for preparing hollow cylindrical torsional shear specimens of non-through fractured rock mass, characterized in that: The invention comprises a bottom plate (1), on which an outer panel (2), an inner panel (3) and an intermediate support (4) are movably connected in sequence from the outside to the inside, and a gap is formed between the outer panel (2) and the inner panel (3); an insert (5) is sleeved on the inner panel (3), and the outer edge of the insert (5) is located in the gap, and the inner edge is inserted into the intermediate support (4).

2. The mold for preparing hollow cylindrical torsional shear specimens of non-through fractured rock mass according to claim 1, characterized in that: A groove is provided on the outer side wall of the middle support (4), and the inner edge of the insert (5) is located in the groove.

3. The mold for preparing hollow cylindrical torsional shear specimens of non-through fractured rock mass according to claim 1, characterized in that: The outer panel (2) comprises two outer plates (201), and the two outer plates (201) are spliced ​​into a hollow cylinder and connected by a connecting piece.

4. The mold for preparing hollow cylindrical torsional shear specimens of non-through fractured rock mass according to claim 1, characterized in that: The inner panel (3) comprises four inner panels (301), and the four inner panels (301) are spliced ​​together to form a hollow cylinder; a crack (6) is opened along the radial direction of the hollow cylinder, and the insert (5) is located in the crack (6).

5. The mold for preparing hollow cylindrical torsional shear specimens of non-through fractured rock mass according to claim 1, characterized in that: The bottom plate (1) is provided with a first groove (7) and a second groove (8); the bottoms of the inner panel (3) and the middle support (4) are located in the first groove (7); and the bottom of the outer panel (2) is located in the second groove (8).

Images