Equal strain direct shear apparatus

Abstract

The utility model discloses an equal-strain direct shear apparatus, belongs to the technical field of rock-soil shear force detection, and solves the problems. Comprising. When the shear strength of a soil block needs to be detected, people only need to take the shear ring, align the blade surface of the shear ring to the soil block to be processed, insert the shear ring into the soil block, remove the redundant soil block, and place the upper shear box on the lower shear box to complete detachable connection of the upper shear box and the lower shear box. Then the shearing ring with the soil blocks is placed on the upper shearing box and pressed downwards, the soil blocks enter the containing groove and the containing through groove, and then the upper shearing box and the lower shearing box are fed into an equal-strain direct shear apparatus for shear strength detection in the horizontal direction.

Description

Technical Field

[0001] The utility model relates to the technical field of rock and soil shear force detection, in particular to an isostrain direct shear instrument. Background Art

[0002] The isostrain direct shear apparatus is mainly used to measure the shear strength of soil. Four soil samples are usually used to apply horizontal forces under different vertical pressures to shear in order to obtain the shear stress at failure. Then the shear strength parameters of the soil are determined according to Coulomb's law. The shear box of the isostrain direct shear apparatus can simultaneously apply vertical pressure and shear the soil sample at a constant rate to measure its corresponding horizontal shear stress, which is used for routine determination of the shear strength of soil samples.

[0003] The shear box of the existing isostrain direct shear instrument includes an upper shear box and a lower shear box, which are connected through. A certain gap is provided between the outer wall of the upper shear box and the inner wall of the lower shear box, and the soil sample is placed in the upper shear box. During the test, the soil sample is subjected to vertical pressure, the upper shear box is fixed to the cutting ring by bolts, and the lower shear box is fixed to the push rod by bolts. The lower shear box is moved by the thrust, causing the upper shear box and the lower shear box to be misaligned, so that the soil sample in the upper shear box is sheared, and then the shear strength of the soil sample is measured.

[0004] After completing a single shear strength test, the soil blocks filled in the upper shear box and the lower shear box need to be taken out before the next subsequent test can be carried out. The soil blocks completely filled between the two are in a state close to an interference fit with the upper shear box and the lower shear box, so it is more difficult to take out the soil blocks.

[0005] Therefore, an isostrain direct shear apparatus is proposed to solve or alleviate the above problems. Utility Model Content

[0006] The purpose of the utility model is to solve the shortcomings existing in the prior art, and the proposed equal strain direct shear instrument is easy to operate when used to detect the shear strength of soil blocks. It only requires taking the shear ring, aligning its blade surface with the soil block to be processed, and inserting the shear ring into the soil block, then removing the excess soil block, and placing the upper shear box on the lower shear box to complete the detachable connection between the two. Next, place the shear ring with the soil block on the upper shear box, press downward to allow the soil block to enter the receiving groove and the receiving through groove, and finally send the upper shear box and the lower shear box into the equal strain direct shear instrument for shear strength detection in the horizontal direction. The operation process is simple and easy, and the operator can easily complete the task of detecting the shear strength of the soil block.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] The isostrain direct shear instrument comprises a lower shear box with a receiving groove, an upper shear box detachably connected thereto and having a receiving through groove, and a pressure cover located in the receiving through groove, wherein a through hole is provided on the top surface of the pressure cover, and a guide column which can be vertically displaced is detachably connected in the through hole, and the lower end of the guide column is arranged as a conical tip.

[0009] Preferably, an internal thread 1 is provided on the inner circumferential wall of the through hole, an external thread 1 is provided on the outer circumferential wall of the guide column, and the guide column is threadably connected to the through hole via the external thread 1 and the internal thread 1.

[0010] Preferably, the upper end of the guide column is coaxially fixedly connected with a connecting column, and the upper end of the connecting column is fixedly connected with an end head with a cross-sectional area larger than that of the connecting column.

[0011] Preferably, the upper end of the inner circumferential wall of the accommodating through groove is provided with internal thread 2, the outer circumferential wall of the pressure cover is provided with external thread 2 threadedly connected to the internal thread 2, and the sum of the pitches of the internal thread 2 is one quarter of the depth of the accommodating through groove.

[0012] Preferably, the upper shear box is provided with a plurality of insertion holes penetrating the upper shear box, and the top surface of the lower shear box is provided with a slot connected to the slot, and a latch is embedded in both the slot and the insertion holes.

[0013] Preferably, two limiting plates are fixedly connected to the top surface of the upper shear box, and the distance between the two limiting plates is equal to the width of the upper shear box.

[0014] Preferably, the upper end of the limiting piece is folded outward to form a guide piece, and the connection between the guide piece and the limiting piece is an arc transition.

[0015] The utility model has the following beneficial effects:

[0016] The utility model provides a series of simple operation steps for operators when it is necessary to test the shear strength of soil blocks. During the whole process, operators only need to easily complete the following steps. First, take out the shear ring to measure the shear strength of the soil block, accurately align the blade surface of the shear ring with the soil block to be processed, and ensure its stability and accuracy. Secondly, slowly insert the shear ring into the soil block, and through appropriate force and angle, the shear ring can be correctly embedded in the soil block to ensure that the shear ring can be correctly fixed in the soil block. Then, remove the excess soil block, and use appropriate tools, such as a knife or a digging tool, to remove the excess parts around the soil block, so that the connection between the shear ring and the soil block can be tighter. And reduce the impact of external factors on the shear strength test. Then, place the upper shear box on the lower shear box. The two are combined through a detachable connection method to ensure that the connection is firm and reliable, so as to ensure that there will be no errors or inaccuracies during the test. Then, place the shear ring with the soil block on the upper shear box and press down. By applying appropriate force, the soil block can smoothly enter the receiving groove and the receiving through groove. Finally, send the upper shear box and the lower shear box into the equal strain direct shear instrument for horizontal shear strength detection. The equal strain direct shear instrument will accurately calculate the shear strength of the soil block and output the corresponding test results. Through the above steps, the operator can quickly and accurately complete the soil block shear strength test. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 It is an exploded view of the utility model;

[0019] Figure 3 It is a cross-sectional view of the pressure cover in the utility model.

[0020] 1. Lower shear box; 2. Slot; 3. Accommodating slot; 41. Limiting piece; 42. Guide piece; 5. Upper shear box; 61. Accommodating through slot; 62. Second internal thread; 7. Socket; 8. Latch; 9. Pressure cover; 91. Second external thread; 92. Through hole; 93. Guide column; 94. Connecting column; 95. End; 96. First internal thread; 97. Tip. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0022] Equal strain direct shear apparatus, such as Figure 1 and 2As shown, it includes a lower shear box 1 with an accommodating groove 3, an upper shear box 5 detachably connected thereto and with an accommodating through groove 61, and a pressure cover 9 located in the accommodating through groove 61.

[0023] like Figure 2 As shown, two limit plates 41 are fixedly connected to the top surface of the upper shear box 5, the spacing between the two limit plates 41 is equal to the width of the upper shear box 5, the upper end of the limit plate 41 is folded outward to form a guide plate 42, and the connection between the guide plate 42 and the limit plate 41 is an arc transition, and the upper shear box 5 is provided with a plurality of sockets 7 passing through it, and the top surface of the lower shear box 1 is provided with a slot 2 connected to the slot 2, and a pin 8 is embedded in both the slot 2 and the socket 7.

[0024] like Figure 3 As shown, a through hole 92 is provided on the top surface of the pressure cover 9, and a guide column 93 which can be vertically displaced is detachably connected to the through hole 92, the lower end of the guide column 93 is set as a conical tip 97, the upper end of the guide column 93 is coaxially fixedly connected with a connecting column 94, and the upper end of the connecting column 94 is fixedly connected with an end 95 whose cross-sectional area is larger than that of the connecting column 94. More specifically, an internal thread 1 96 is provided on the inner circumferential wall of the through hole 92, an external thread 1 is provided on the outer circumferential wall of the guide column 93, the guide column 93 is threadedly connected to the through hole 92 via the external thread 1 and the internal thread 1 96, an internal thread 2 62 is provided on the upper end of the inner circumferential wall of the accommodating through groove 61, and an external thread 2 91 is provided on the outer circumferential wall of the pressure cover 9 which is threadedly connected to the internal thread 2 62, and the sum of the pitches of the internal thread 2 62 is one-fourth of the depth of the accommodating through groove 61.

[0025] When the equal strain direct shear apparatus needs to perform shear force testing on a soil sample, the operator first needs to take the shear ring, align the blade of the shear ring with the soil block, and then insert the shear ring into it so that the soil sample can fill the space inside the shear ring, and then remove the excess soil sample.

[0026] Then, people manually place the upper shear box 5 on the top surface of the lower shear box 1. When the upper shear box 5 is placed on the lower shear box 1, the bottom edge of the upper shear box 5 will contact the guide piece 42. Under the guidance of the guide piece 42, it will be embedded between the two limiting pieces 41 on both sides, thereby ensuring that the accommodating through groove 61 of the upper shear box 5 is connected with the accommodating groove 3 of the lower shear box 1 and is coaxially arranged. At this time, people insert the pin 8 into the socket 7 and the slot 2, so that the upper shear box 5 and the lower shear box 1 can complete a detachable connection.

[0027] Afterwards, people place the shear ring with the soil sample on the receiving groove 61 of the upper shear box 5, and then manually send the soil sample in the shear ring into the receiving groove 3 and the receiving groove 61. Then people take the pressing block and screw the pressing block into the internal thread 62 through the external thread 91, so that the pressing block can seal the top of the soil sample to prevent the soil block from flying.

[0028] Subsequently, it is only necessary to send the upper shear box 5 and the lower shear box 1 into the equal strain direct shear apparatus for testing. After the test is completed, people manually rotate the end 95, thereby driving the connecting column 94 and the guide column 93 to rotate. Under the guidance of the internal thread 96 and the external thread 1, the guide column 93 dives, so that the tip 97 can be poked into the tested soil sample, so that the soil sample is broken, and then the tested soil sample is conveniently removed.

[0029] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An isostrain direct shear apparatus, comprising a lower shear box (1) with a receiving slot (3), an upper shear box (5) detachably connected thereto and having a receiving slot (61), and a gland (9) located in the receiving slot (61), characterized in that: A through hole (92) is provided on the top surface of the gland (9), and a vertically displaceable guide column (93) is detachably connected to the through hole (92), and the lower end of the guide column (93) is arranged as a conical tip (97).

2. The isostrain direct shear apparatus according to claim 1, characterized in that: An internal thread (96) is provided on the inner peripheral wall of the through hole (92), and an external thread (96) is provided on the outer peripheral wall of the guide column (93). The guide column (93) is threadedly connected to the through hole (92) via the external thread (96) and the internal thread (96).

3. The isostrain direct shear apparatus according to claim 1, characterized in that: The upper end of the guide column (93) is coaxially fixedly connected to a connecting column (94), and the upper end of the connecting column (94) is fixedly connected to an end head (95) having a larger cross-sectional area than the connecting column (94).

4. The isostrain direct shear apparatus according to claim 1, characterized in that: The upper end of the inner peripheral wall of the accommodating through groove (61) is provided with an internal thread (62), and the outer peripheral wall of the pressure cover (9) is provided with an external thread (91) threadedly connected to the internal thread (62), and the sum of the pitches of the internal thread (62) is one quarter of the depth of the accommodating through groove (61).

5. The isostrain direct shear apparatus according to claim 1, characterized in that: The upper shear box (5) is provided with a plurality of insertion holes (7) penetrating the upper shear box, and the top surface of the lower shear box (1) is provided with a slot (2) connected to the slot (2), and a latch (8) is embedded in both the slot (2) and the insertion holes (7).

6. The isostrain direct shear apparatus according to claim 1, characterized in that: Two limiting plates (41) are fixedly connected to the top surface of the upper shear box (5), and the distance between the two limiting plates (41) is equal to the width of the upper shear box (5).

7. The isostrain direct shear apparatus according to claim 6, characterized in that: The upper end of the limiting piece (41) is folded outward to form a guide piece (42), and the connection between the guide piece (42) and the limiting piece (41) is an arc transition.

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