Civil engineering material shear strength testing device

Abstract

The utility model discloses a civil engineering material shear strength test device, and belongs to the technical field of civil engineering shear strength tests. Comprising an operation platform; the lower shear box is detachably mounted on the operating platform; the upper shear box is arranged above the lower shear box; the lower pressurizing frame is inserted into the operation platform in a sliding manner; the upper pressurizing frame is arranged above the upper shear box, the upper pressurizing frame and the lower pressurizing frame are used for pressurizing a sample, and the upper shear box can deflect; the two pressure applying mechanisms are fixed to the operation platform, the pressure applying mechanisms are in transmission connection with the lower pressure applying frame and the upper pressure applying frame, and the pressure applying mechanisms are used for driving the lower pressure applying frame and the upper pressure applying frame to synchronously move oppositely or adjacently; a first servo electric cylinder; the technical effects that the samples can be uniformly distributed in the upper shear box and the lower shear box, and the measurement of the shear strength and the shear modulus and the deviation generated by a test result are reduced are achieved.

Description

Technical Field

[0001] This application relates to the technical field of civil engineering shear degree tests, and more specifically, to a shear strength test device for civil engineering materials. Background Art

[0002] The shear strength test of civil engineering materials is an important means to evaluate the resistance performance of materials under the action of shear force. It is mainly used to test parts and materials under shear loads, such as connectors in bridges and buildings, soil and rocks, etc. Among them, the direct shear test is applicable to the shear strength test of soil and rocks. The main purpose is to simulate the failure process of the soil body under the action of shear force and measure the shear strength index of the soil. However, in the current direct shear test, after the specimen is placed in the lower shear box, a vertical load is applied unidirectionally from top to bottom by the force application mechanism, and the specimen is compressed.

[0003] However, after the specimen is compressed, it will cause the volume of the specimen placed in the upper and lower shear boxes to be different, and then the problem of uneven specimen distribution during the shear test. Uneven specimen distribution will lead to uneven stress distribution on the shear surface, thus affecting the measurement results of shear strength and shear modulus and causing deviation in the test results.

[0004] In view of this, we propose a shear strength test device for civil engineering materials. Summary of the Invention

[0005] Technical Problems to be Solved

[0006] The purpose of this application is to provide a shear strength test device for civil engineering materials, which solves the technical problems in the above background art and realizes the technical effect that the specimen can be evenly distributed in the upper shear box and the lower shear box, reducing the deviation in the measurement of shear strength and shear modulus and the test results.

[0007] Technical Solution

[0008] The technical solution of this application provides a shear strength test device for civil engineering materials, including:

[0009] An operation platform;

[0010] A lower shear box, detachably installed on the operation platform;

[0011] An upper shear box, placed above the lower shear box;

[0012] A lower pressure frame, slidably inserted on the operation platform;

[0013] An upper pressure frame, placed above the upper shear box. The upper pressure frame and the lower pressure frame are used to press the specimen, and the upper shear box can be deflected;

[0014] A pressure mechanism is provided with two groups, the pressure mechanism is fixed on the operating platform, the pressure mechanism is transmission-connected with the lower pressure frame and the upper pressure frame, and the pressure mechanism is used to drive the lower pressure frame and the upper pressure frame to move synchronously relative to or adjacent to each other;

[0015] A first servo electric cylinder is fixed on one side of the operating platform, the first servo electric cylinder is horizontally retracted, and the first servo electric cylinder is placed on one side of the upper shear box;

[0016] A micrometer is arranged on a side of the operating platform away from the first servo electric cylinder, and the micrometer is detachably arranged between the upper shear box and the operating platform.

[0017] As an optional solution of the technical solution of this application document, the operating platform includes an operating panel, a supporting column and an adjusting screw, the supporting column is fixed to one side edge of the operating panel, the adjusting screw is threadedly connected to the supporting column, and a card slot adapted to the lower shear box is opened on the upper surface of the operating panel;

[0018] The micrometer comprises a force ring, a dial indicator and a step block. The dial indicator is fixed in the force ring. The force ring is symmetrically fixed with step blocks. One side of the step block is provided with a mounting hole adapted to the adjusting screw.

[0019] As an optional solution of the technical solution of the present application document, a blocking plate that abuts against the lower shear box is fixedly installed on one side of the operation panel close to the supporting column, and a strap is fixedly installed on one side of the upper shear box.

[0020] As an optional solution to the technical solution of the present application document, the lower pressure frame includes a lower cross beam, a lower vertical rod and a lower top cap, both ends of the lower cross beam are vertically fixed with lower vertical rods, the lower top cap is fixed on the lower cross beam and placed between the two lower vertical rods, and the operating panel is symmetrically provided with rectangular holes adapted to the lower vertical rods.

[0021] As an optional scheme of the technical scheme of the present application document, the upper pressure frame includes an upper cross beam, an upper vertical rod, an upper top cap and a pressure sensor, the upper vertical rods are vertically fixed at both ends of the upper cross beam, the upper cross beam is symmetrically fixed with sleeves, a U-shaped frame is slidably inserted into the two sleeves, the U-shaped frame is symmetrically slidably inserted with an insertion rod, the insertion rod is fixed on the upper top cap, the pressure sensor is fixed on the upper surface of the upper top cap and placed under the U-shaped frame, the upper end of the U-shaped frame and the lower end of the sleeve are both provided with pin holes, a pin is inserted in the pin hole, a power-assisting hole is provided at the upper end of the insertion rod, the upper cross beam and the lower cross beam have the same structure, the upper vertical rod and the lower vertical rod have the same structure, the distance between the lower top cap and the lower cross beam and the distance between the upper top cap and the upper cross beam are the same.

[0022] As an alternative embodiment of the technical solution of this application document, the pressing mechanism includes a second servo electric cylinder, a connecting arm, a movable arm, a lower ear plate and an upper ear plate. The second servo electric cylinder is fixed on the operation platform. Both ends of the connecting arm are rotatably connected to the movable arms. One of the movable arms is rotatably connected to the upper ear plate, and the other movable arm is rotatably connected to the lower ear plate. The upper ear plate is fixed with a shaft rod rotatably connected to the upper vertical rod, and the lower ear plate is fixed to the lower vertical rod.

[0023] As an alternative embodiment of the technical solution of this application document, the connecting arm is vertically fixed with a positioning rod parallel to the telescopic direction of the second servo electric cylinder. A through hole adapted to the positioning rod is provided on the cylinder block of the second servo electric cylinder.

[0024] Beneficial effects

[0025] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0026] 1. In this application, the pressing mechanism drives the upper pressing frame and the lower pressing frame to move relatively synchronously, applying a vertical load to the specimen. At the same time, it also enables the specimen to be evenly distributed in the upper shear box and the lower shear box, reducing the deviation in the measurement of the shear strength and shear modulus and the test results.

[0027] 2. In this application, the insertion rod vertically slides and inserts at the lower end of the U-shaped frame. Therefore, when the upper pressing frame and the lower pressing frame apply pressure to the specimen relatively, the load force of the specimen can be observed through the pressure sensor at this time. And through the sliding insertion of the U-shaped frame and the sleeve, and with the cooperation of the insertion pin, the upper top cap can be lifted upward to facilitate the assembly of the upper shear box and the lower shear box with the operation platform. Description of the drawings

[0028] Figure 1 It is a schematic diagram of the overall structure of a shear strength test device for civil engineering materials disclosed in a preferred embodiment of this application;

[0029] Figure 2 It is a schematic diagram of the overall exploded structure of a shear strength test device for civil engineering materials disclosed in a preferred embodiment of this application;

[0030] Figure 3 It is a schematic diagram of the partial exploded structure of the pressing mechanism of a shear strength test device for civil engineering materials disclosed in a preferred embodiment of this application;

[0031] Figure 4 It is a schematic diagram of the structure of the operation platform of a shear strength test device for civil engineering materials disclosed in a preferred embodiment of this application;

[0032] Figure 5Schematic diagram of the lower pressure frame structure of a shear strength test device for civil engineering materials disclosed in a preferred embodiment of the present application;

[0033] Figure 6 Schematic diagram of the upper pressure frame structure of a shear strength test device for civil engineering materials disclosed in a preferred embodiment of the present application;

[0034] Figure 7 Exploded structure diagram of the upper pressure frame of a shear strength test device for civil engineering materials disclosed in a preferred embodiment of the present application;

[0035] Description of the reference numerals in the figure:

[0036] 1. Operation platform; 11. Operation panel; 111. Card slot; 112. Rectangular hole; 12. Support column; 13. Adjusting screw; 14. Baffle; 2. Lower shear box; 3. Upper shear box; 31. Laying board; 4. Lower pressure frame; 41. Lower cross beam; 42. Lower vertical rod; 421. Lower ear plate; 43. Lower top cap; 5. Upper pressure frame; 51. Upper cross beam; 511. Sleeve; 5111. Pin hole; 512. U-shaped frame; 513. Insertion rod; 5131. Boosting hole; 514. Insert pin; 52. Upper vertical rod; 521. Upper ear plate; 522. Shaft rod; 53. Upper top cap; 54. Pressure sensor; 6. Pressing mechanism; 61. Second servo electric cylinder; 611. Through hole; 62. Connecting arm; 63. Movable arm; 64. Positioning rod; 7. First servo electric cylinder; 8. Micrometer; 81. Load cell; 82. Micrometer; 83. Laying block; 831. Mounting hole; 9. Stone plate. Detailed implementation manners

[0037] The present application will be further described in detail below with reference to the accompanying drawings of the specification.

[0038] A shear strength test device for civil engineering materials includes:

[0039] An operation platform 1;

[0040] A lower shear box 2, detachably installed on the operation platform 1;

[0041] An upper shear box 3, placed above the lower shear box 2;

[0042] A lower pressure frame 4, slidably inserted on the operation platform 1;

[0043] An upper pressure frame 5, placed above the upper shear box 3. The upper pressure frame 5 and the lower pressure frame 4 are used to press the specimen, and the upper shear box 3 can be deflected;

[0044] The pressure mechanism 6 is provided with two groups, the pressure mechanism 6 is fixed on the operating platform 1, the pressure mechanism 6 is transmission-connected with the lower pressure frame 4 and the upper pressure frame 5, and the pressure mechanism 6 is used to drive the lower pressure frame 4 and the upper pressure frame 5 to move synchronously relative to or adjacent to each other;

[0045] The first servo electric cylinder 7 is fixed on one side of the operating platform 1, and the first servo electric cylinder 7 is horizontally retracted. The first servo electric cylinder 7 is placed on one side of the upper shear box 3;

[0046] The micrometer 8 is arranged on a side of the operating platform 1 away from the first servo electric cylinder 7 , and the micrometer 8 is detachably arranged between the upper shear box 3 and the operating platform 1 .

[0047] Reference Figure 1 - Figure 7 , install the lower shear box 2 on the operating platform 1, then put a stone plate 9, then put the sample into the lower shear box 2, then put another stone plate 9 on top of the sample, then put the upper shear box 3 on top of the lower shear box 2, start the pressure mechanism 6, the pressure mechanism 6 drives the lower pressure frame 4 and the upper pressure frame 5 to move synchronously relative to each other, so that the samples in the upper shear box 3 and the lower shear box 2 move and are pressurized, and at the same time, the fitting surface of the upper shear box 3 and the lower shear box 2 is the fitting point of the lower pressure frame 4 and the upper pressure frame 5, and then at the current pressure When the pressure frame 4 and the upper pressure frame 5 relatively pressurize the sample, the sample can be evenly distributed in the upper shear box 3 and the lower shear box 2 after being pressurized, and then the micrometer 8 is fixed between the upper shear box 3 and the operating platform 1 and offset each other. Finally, the first servo electric cylinder 7 applies a horizontal force to the upper shear box 3 to start shearing. The reading of the micrometer 8 continues to increase. When the value stabilizes or significantly retreats, the sample is sheared and damaged. At the same time, the upper pressure frame 5 can be deflected in the direction of the shear force to avoid interference from the upper pressure frame 5 during the shear test.

[0048] The operating platform 1 includes an operating panel 11, a supporting column 12 and an adjusting screw 13. The supporting column 12 is fixed to one side edge of the operating panel 11. The adjusting screw 13 is threadedly connected to the supporting column 12. A slot 111 adapted to the lower shear box 2 is provided on the upper surface of the operating panel 11.

[0049] The micrometer 8 includes a force ring 81 , a dial gauge 82 and a step block 83 . The dial gauge 82 is fixed in the force ring 81 . The step blocks 83 are symmetrically fixed to the force ring 81 . One side of the step block 83 is provided with a mounting hole 831 adapted to the adjusting screw 13 .

[0050] Reference Figure 1 and Figure 2 and Figure 4, insert the lower shear box 2 into the card slot 111 to position the lower shear box 2 and prevent it from moving during the shear test. The support column 12 is fixed to the left edge of the operation panel 11, and the first servo electric cylinder 7 is fixed to the right edge of the operation panel 11. The adjusting screw 13 is parallel to the telescopic direction of the first servo electric cylinder 7. The right side of the block 83 abuts against the left outer surface of the upper shear box 3. The adjusting screw 13 passes through the mounting hole 831, and by rotating the adjusting screw 13 clockwise, the adjusting screw 13 moves towards the upper shear box 3, thereby installing the load cell 81 between the support column 12 and the upper shear box 3, and then zeroing the reading of the dial indicator 82.

[0051] On one side of the operation panel 11 close to the support column 12, a blocking plate 14 that abuts against the lower shear box 2 is fixedly installed, and a connecting plate 31 is fixedly installed on one side of the upper shear box 3.

[0052] Refer to Figure 1 and Figure 2 , when assembling the micrometer 8, place the right side of the block 83 on the connecting plate 31 to improve the stability of the installation of the load cell 81 and avoid the problem of the load cell 81 falling during the assembly of the load cell 81. At the same time, fix the blocking plate 14 on the left side of the card slot 111 to block the lower shear box 2 and prevent the lower shear box 2 from tipping over during the shear test.

[0053] The lower pressing frame 4 includes a lower cross beam 41, lower vertical rods 42, and a lower top cap 43. At both ends of the lower cross beam 41, the lower vertical rods 42 are vertically fixed, and the lower top cap 43 is fixed on the lower cross beam 41 and placed between the two lower vertical rods 42. The operation panel 11 is symmetrically provided with rectangular holes 112 adapted to the lower vertical rods 42.

[0054] Refer to Figure 2 and Figure 4 and Figure 5 , the lower cross beam 41 and the lower top cap 43 are fixedly connected by a top rod. The top rod passes through the operation panel 11, and the lower vertical rods 42 are slidably inserted into the rectangular holes 112 to position the lower pressing frame 4 during lifting and lowering. The lower top cap 43 is placed on the upper surface of the operation panel 11, and when the lower shear box 2 is installed in the card slot 111, the lower top cap 43 is placed inside the lower shear box 2.

[0055] The upper pressing frame 5 includes an upper cross beam 51, upper vertical rods 52, an upper top cap 53 and a pressure sensor 54. At both ends of the upper cross beam 51, the upper vertical rods 52 are vertically fixed. The upper cross beam 51 is symmetrically fixed with sleeves 511. A U-shaped frame 512 is slidably inserted into the two sleeves 511. The U-shaped frame 512 is symmetrically slidably inserted with insertion rods 513. The insertion rods 513 are fixed on the upper top cap 53. The pressure sensor 54 is fixed on the upper surface of the upper top cap 53 and is placed below the U-shaped frame 512. Pin holes 5111 are opened at the upper ends of the U-shaped frame 512 and the lower ends of the sleeves 511. A pin 514 is inserted into the pin holes 5111. A boosting hole 5131 is opened at the upper end of the insertion rod 513. The upper cross beam 51 and the lower cross beam 41 have the same structure, the upper vertical rods 52 and the lower vertical rods 42 have the same structure, and the distances between the lower top cap 43 and the lower cross beam 41 and between the upper top cap 53 and the upper cross beam 51 are the same.

[0056] Referring to Figure 2 and Figure 6 and Figure 7 When the pin holes 5111 of the U-shaped frame 512 correspond to the pin holes 5111 of the sleeves 511 and the pin 514 is inserted into the pin holes 5111 and the U-shaped frame 512 abuts against the pressure sensor 54, the distances between the lower top cap 43 and the lower cross beam 41 and between the upper top cap 53 and the upper cross beam 51 are the same at this time. Therefore, when the lower pressing frame 4 and the upper pressing frame 5 move relatively synchronously, the upper top cap 53 and the lower top cap 43 move relatively synchronously at this time. When pressing, the pressure sensor 54 can be used to monitor the pressing pressure on the specimen. At the same time, the insertion rod 513 is vertically slidably inserted on the U-shaped frame 512. When the upper shear box 3 is subjected to a horizontal shear force, the pressure sensor 54 can be prevented from being subjected to a horizontal shear force. And when the test is over, the pin 514 is removed from the pin holes 5111, the U-shaped frame 512 is contracted upward, and the upper top cap 53 is taken out of the upper shear box 3. At this time, the upper shear box 3 can be horizontally taken out. At the same time, through the boosting hole 5131, a rope is threaded into the boosting hole 5131, and then the rope is pulled upward to facilitate taking out the upper top cap 53 from the upper shear box 3.

[0057] The pressing mechanism 6 includes a second servo electric cylinder 61, a connecting arm 62, a movable arm 63, a lower ear plate 421 and an upper ear plate 521. The second servo electric cylinder 61 is fixed on the operation platform 1. At both ends of the connecting arm 62, the movable arms 63 are rotatably connected by shafts. One movable arm 63 is rotatably connected to the upper ear plate 521 by a shaft, and the other movable arm 63 is rotatably connected to the lower ear plate 421 by a shaft. The upper ear plate 521 is fixed with a shaft rod 522 rotatably connected to the upper vertical rod 52, and the lower ear plate 421 is fixed to the lower vertical rod 42.

[0058] Referring to Figure 1 , Figure 3 - Figure 6, the second servo electric cylinder 61 is perpendicular to the telescopic direction of the first servo electric cylinder 7. The movable arm 63 is fixed on the piston rod of the second servo electric cylinder 61. Both the upper and lower ends of the movable arm 63 are rotatably connected to the movable arm 63. At the same time, the upper movable arm 63 is rotatably connected to the upper ear plate 521, and the lower movable arm 63 is rotatably connected to the lower ear plate 421. The two movable arms 63 form a V-shaped structure with an opening facing outwards. Therefore, when the second servo electric cylinder 61 extends, the acute angle between the two movable arms 63 becomes smaller, pulling the lower vertical rod 42 and the upper vertical rod 52 to move relative to each other, and causing the upper top cap 53 and the lower top cap 43 to apply pressure to the specimen. When the second servo electric cylinder 61 contracts, it pulls the connecting arm 62 to move outwards. At this time, the connecting arm 62 pushes the acute angle between the two movable arms 63 to gradually become larger, thereby causing the lower vertical rod 42 and the upper vertical rod 52 to move adjacent to each other to facilitate the removal of the specimen. At the same time, the shaft rod 522 is rotatably connected to the lower end of the upper vertical rod 52. When the upper shear box 3 is subjected to a horizontal shear force and the upper shear box 3 moves horizontally, the upper pressure frame 5 can deflect around the shaft rod 522, avoiding the interference of the upper pressure frame 5 with the horizontal displacement of the upper shear box 3.

[0059] A positioning rod 64 is vertically fixed to the connecting arm 62. The positioning rod 64 is parallel to the telescopic direction of the second servo electric cylinder 61. A through hole 611 adapted to the positioning rod 64 is provided on the cylinder block of the second servo electric cylinder 61.

[0060] Refer to Figure 3 and Figure 4 , during the telescopic process of the piston rod of the second servo electric cylinder 61, through the positioning rod 64 fixed to the connecting arm 62, the positioning rod 64 is slidably inserted into the through hole 611. Under the combined action of the positioning rod 64 and the piston rod, the connecting arm 62 is positioned to prevent the connecting arm 62 from rotating.

[0061] Working principle: First, the second servo electric cylinder 61 contracts, the piston rod contracts into the cylinder body, the piston rod pulls the two connecting arms 62 to move away from each other, the acute angle between the two movable arms 63 on the connecting arm 62 gradually becomes larger, and the upper vertical rod 42 and the lower vertical rod 52 are supported to move away from each other through the two movable arms 63 respectively. Then, the lower shear box 2 is placed into the card slot 111, and then the pin 514 is taken out from the pin hole 5111. A stone plate 9 is placed into the lower shear box 2, the specimen is placed into the lower shear box 2, and then another stone plate 9 is placed into the lower shear box 2 and placed above the specimen. Then, the U-shaped frame 512 is moved upward, the upper shear box 3 is placed above the lower shear box 2, the pin hole 5111 of the U-shaped frame 512 is aligned with the pin hole 5111 of the sleeve 511, and the pin 514 is inserted into the pin hole 5111. The right side of the latch 83 is placed on the latch plate 31, the adjusting screw 13 is inserted into the mounting hole 831, and the adjusting screw 13 is rotated clockwise so that the right side of the latch 83 abuts against the upper shear box 3. The piston rod of the second servo electric cylinder 61 extends, the acute angle between the two movable arms 63 gradually becomes smaller, the lower vertical rod 42 and the upper vertical rod 52 move relative to each other, the upper top cap 53 and the lower top cap 43 apply pressure to the specimen, and the reading of the pressure sensor 54 is observed and pressured to the preset pressure. The reading of the micrometer 82 is reset to zero. Finally, a horizontal force is applied to the upper shear box 3 by the first servo electric cylinder 7 to start shearing. The reading of the micrometer 8 continuously increases. When the value is stable or significantly retreats, the specimen is sheared and damaged at this time, and the shear force test of the specimen can be completed, and the maximum value is the maximum shear strength of the specimen.

Claims

1. A shear strength test device for civil engineering materials, characterized in that: Comprising: An operating platform (1); A lower shearing box (2), detachably installed on the operating platform (1); An upper shearing box (3), placed above the lower shearing box (2); A lower pressing frame (4), slidably inserted on the operating platform (1); An upper pressing frame (5), placed above the upper shearing box (3), the upper pressing frame (5) and the lower pressing frame (4) being used for pressing a specimen, and the upper shearing box (3) being deflectable; A pressing mechanism (6), provided in two groups, the pressing mechanism (6) being fixed on the operating platform (1), the pressing mechanism (6) being in transmission connection with the lower pressing frame (4) and the upper pressing frame (5), and the pressing mechanism (6) being used for driving the lower pressing frame (4) and the upper pressing frame (5) to move relatively or adjacently synchronously; A first servo electric cylinder (7), fixed on one side of the operating platform (1), the first servo electric cylinder (7) extending and retracting horizontally, and the first servo electric cylinder (7) being placed on one side of the upper shearing box (3); A micrometer (8), arranged on the side of the operating platform (1) away from the first servo electric cylinder (7), and the micrometer (8) being detachably arranged between the upper shearing box (3) and the operating platform (1).

2. The shear strength test device for a civil engineering material according to claim 1, characterized in that: The operating platform (1) includes an operating panel (11), supporting columns (12) and adjusting screws (13), the supporting columns (12) being fixed on one side edge of the operating panel (11), the adjusting screws (13) being threadedly connected to the supporting columns (12), and a card slot (111) adapted to the lower shearing box (2) being formed on the upper surface of the operating panel (11); The micrometer (8) includes a load cell (81), a micrometer (82) and a connecting block (83), the micrometer (82) being fixed inside the load cell (81), the load cell (81) being symmetrically fixed with the connecting blocks (83), and a mounting hole (831) adapted to the adjusting screw (13) being formed in one of the connecting blocks (83).

3. The shear strength test device for a civil engineering material according to claim 2, characterized in that: A blocking plate (14) abutted against the lower shearing box (2) is fixedly installed on one side of the operating panel (11) close to the supporting column (12), and a connecting plate (31) is fixedly installed on one side of the upper shearing box (3).

4. The shear strength test device for a civil engineering material according to claim 2, characterized in that: The lower pressing frame (4) includes a lower cross beam (41), lower vertical rods (42) and a lower top cap (43), the lower cross beam (41) being perpendicularly fixed with the lower vertical rods (42) at both ends, the lower top cap (43) being fixed on the lower cross beam (41) and placed between the two lower vertical rods (42), and rectangular holes (112) adapted to the lower vertical rods (42) being symmetrically formed in the operating panel (11).

5. The shear strength test device for a civil engineering material according to claim 4, characterized in that: The upper pressing frame (5) includes an upper cross beam (51), upper vertical rods (52), an upper top cap (53) and a pressure sensor (54). At both ends of the upper cross beam (51), upper vertical rods (52) are vertically fixed. The upper cross beam (51) is symmetrically fixed with sleeves (511). A U-shaped frame (512) is slidably inserted into the two sleeves (511). The U-shaped frame (512) is symmetrically slidably inserted with insertion rods (513). The insertion rods (513) are fixed on the upper top cap (53). The pressure sensor (54) is fixed on the upper surface of the upper top cap (53) and is placed below the U-shaped frame (512). A pin hole (5111) is provided at the upper end of the U-shaped frame (512) and the lower end of the sleeve (511). A pin (514) is inserted into the pin hole (5111). A boosting hole (5131) is provided at the upper end of the insertion rod (513). The upper cross beam (51) and the lower cross beam (41) have the same structure. The upper vertical rods (52) and the lower vertical rods (42) have the same structure. The distance between the lower top cap (43) and the lower cross beam (41) is the same as the distance between the upper top cap (53) and the upper cross beam (51).

6. An apparatus for testing the shear strength of a civil engineering material according to claim 5, characterized in that: The pressing mechanism (6) includes a second servo electric cylinder (61), a connecting arm (62), a movable arm (63), a lower ear plate (421) and an upper ear plate (521). The second servo electric cylinder (61) is fixed on the operation platform (1). At both ends of the connecting arm (62), movable arms (63) are rotatably connected by shafts. One side of the movable arm (63) is rotatably connected to the upper ear plate (521) by a shaft, and the other side of the movable arm (63) is rotatably connected to the lower ear plate (421) by a shaft. The upper ear plate (521) is fixed with a shaft rod (522) rotatably connected to the upper vertical rod (52). The lower ear plate (421) is fixed on the lower vertical rod (42).

7. The shear strength test device for a civil engineering material according to claim 6, characterized in that: The connecting arm (62) is vertically fixed with a positioning rod (64). The positioning rod (64) is parallel to the telescopic direction of the second servo electric cylinder (61). A through hole (611) adapted to the positioning rod (64) is provided on the cylinder body of the second servo electric cylinder (61).

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