A gravel soil direct shear apparatus with controllable humidity environment

Abstract

The present invention discloses a gravel soil direct shear tester with a controllable humidity environment, comprising: a base; a humidity regulating mechanism, the humidity regulating mechanism being fixedly connected to the top of the base; a sample shearing mechanism, the sample shearing mechanism comprising an upper shearing portion and a lower shearing portion, both of which are mounted on the humidity regulating mechanism, the upper shearing portion being located above the lower shearing portion, a shearing seam regulating gasket being provided between the upper shearing portion and the lower shearing portion, and the lower shearing portion being slidably connected to the bottom end of the humidity regulating mechanism; a loading mechanism, the loading mechanism comprising a vertical loading portion and a horizontal loading portion, the vertical loading portion being fixedly connected to the top of the base, the vertical loading portion being located above the humidity regulating mechanism, the end of the vertical loading portion extending into the humidity regulating mechanism, the horizontal loading portion being fixedly connected to the humidity regulating mechanism, and the horizontal loading portion being fixedly connected to the lower shearing portion. The present invention can perform direct shear tests on gravel soil under different humidity or suction conditions, and can also perform strength tests on gravel soil under dry-wet cycles.

Description

Technical Field

[0001] The invention relates to the technical field of rock and soil mechanics strength testing, in particular to a gravel soil direct shear instrument with controllable humidity environment. Background Art

[0002] Landslides are highly likely to occur in mountainous areas due to complex lithology, geological structures, and terrain variations, as well as factors such as human intervention and rainfall. Gravel-soil landslides, one of the many types of landslides, are a major geological hazard, causing significant economic losses to the country. Research on the properties of gravel-soil plays a crucial role in preventing and controlling these landslides.

[0003] Gravel soil is characterized by a loose structure, high porosity, and high permeability. Natural climates vary greatly, and under typical climatic conditions, gravel soil is in an unsaturated state. Gravel soil's strength is significantly affected by ambient humidity. During rainfall, air humidity is high, soil suction is low, and strength decreases accordingly. At high temperatures, water evaporates, air humidity decreases, suction increases, and strength increases. The effects of humidity and repeated wet-dry cycles ultimately affect slope stability. Slope instability is largely caused by shear failure, making accurate measurement of shear strength of great engineering significance. Direct shear apparatuses are widely used due to their simplicity and wide applicability. Most direct shear apparatuses on the market are designed for fine-grained soils, with few suitable for gravel soils. While large direct shear apparatuses exist for shearing gravel soil, they cannot control humidity during testing, clearly not meeting our testing conditions. To study the effects of humidity or varying suction on the strength of gravel soil, it was necessary to develop a direct shear apparatus for gravel soil that could control humidity. Summary of the Invention

[0004] The object of the present invention is to provide a gravel soil direct shear apparatus with a controllable humidity environment, comprising:

[0005] base;

[0006] a humidity regulating mechanism, the humidity regulating mechanism being fixedly connected to the top of the base;

[0007] A sample shearing mechanism, comprising an upper shearing portion and a lower shearing portion, both of which are mounted on the humidity control mechanism, the upper shearing portion being located above the lower shearing portion, a shearing gap adjustment gasket being provided between the upper shearing portion and the lower shearing portion, and the lower shearing portion being in sliding contact with the bottom end of the humidity control mechanism;

[0008] The loading mechanism includes a vertical loading part and a horizontal loading part. The vertical loading part is fixed to the top of the base, the vertical loading part is located above the humidity adjustment mechanism, the end of the vertical loading part extends into the humidity adjustment mechanism, the horizontal loading part is fixed to the humidity adjustment mechanism, and the horizontal loading part is fixed to the lower shearing part.

[0009] Preferably, the humidity regulating mechanism includes a relative humidity controller and a sealed box, the relative humidity controller and the sealed box are both fixedly connected to the top of the base, an air inlet pipe is fixedly connected to the outer wall of the top of the sealed box, the relative humidity controller is communicated with the sealed box through the air inlet pipe, an exhaust port is fixedly connected to the outer wall of the bottom of the sealed box, the exhaust port is communicated with the sealed box, valves are installed on the air inlet pipe and the exhaust port, a humidity sensor is fixedly connected to the inner wall of the top of the sealed box, the upper shearing part, the lower shearing part and the horizontal loading part are all installed on the sealed box, a slide is fixedly connected to the inner wall of the bottom end of the sealed box, the lower shearing part is slidably connected to the sealed box through the slide, the vertical loading part is located directly above the sealed box, and the end of the vertical loading part extends into the sealed box.

[0010] Preferably, the upper shearing part includes an upper shearing box, the upper shearing box is located in the sealing box, the upper shearing box is located above the lower shearing part, the shearing seam adjustment gasket is arranged between the upper shearing box and the lower shearing part, the inner wall of the upper shearing box is fixedly connected with a pressure sensing electric sheet, the outer side of the upper shearing box is fixedly connected with a horizontal force transmission rod, the end of the horizontal force transmission rod is fixedly connected to the movable end of the electric-controlled thruster, and the fixed end of the electric-controlled thruster is fixedly connected to the sealing box.

[0011] Preferably, the lower shear part includes a lower shear box and a slide, the lower shear box and the slide are both located in the sealing box, the slide is fixedly connected to the horizontal loading part, the slide is placed on the slide and is slidably connected to the bottom end of the sealing box through the slide, a groove is provided at the top of the slide, a bottom plate is inserted in the groove, and a number of channels are correspondingly provided on the slide and the bottom plate, the lower shear box is located above the slide, the inner side of the lower shear box is fixedly connected to the pressure sensing electric sheet, the outer side of the lower shear box is fixedly connected to the horizontal force transmission rod, the end of the horizontal force transmission rod is fixedly connected to the movable end of the electric-controlled thruster, the fixed end of the electric-controlled thruster is fixedly connected to the top of the slide, the upper shear box is located above the lower shear box, and the shear seam adjustment gasket is provided between the upper shear box and the lower shear box.

[0012] Preferably, the upper shear box and the lower shear box both include two inextensible rigid plates and two extensible rigid plates, the two inextensible rigid plates and the two extensible rigid plates are each provided with a through hole, the two extensible rigid plates are both located between the two inextensible rigid plates, the two inextensible rigid plates and the two extensible rigid plates form a rectangular structure, the inner sides of the two inextensible rigid plates and the two extensible rigid plates are both fixedly connected with the pressure sensing electrode, the outer sides of the two inextensible rigid plates and the two extensible rigid plates are both fixedly connected with the horizontal force transmission rod, the shear seam adjustment gasket is provided between the inextensible rigid plate of the upper shear box and the inextensible rigid plate corresponding to the lower shear box, and the shear seam adjustment gasket is provided between the extensible rigid plate of the upper shear box and the extensible rigid plate corresponding to the lower shear box.

[0013] Preferably, the retractable rigid plate includes a fixed block and a retractable block, the retractable blocks are slidably connected on both sides of the fixed block, a plurality of through holes are provided on the fixed block and the retractable block, the pressure sensing electrode is fixedly connected to the fixed block, and the horizontal force transmission rod is fixedly connected to the fixed block.

[0014] Preferably, the horizontal loading part includes a CNC electric hydraulic jack, which is fixed to the outer wall of the sealing box, and the movable end of the CNC electric hydraulic jack is fixed to a shear force transmission rod, the end of the shear force transmission rod extends into the sealing box and is fixed to the slide, and the shear force transmission rod is fixed to a horizontal stress and displacement sensor.

[0015] Preferably, the vertical loading part includes a vertical hydraulic pump jack, the top of the base is fixedly connected to the vertical reaction frame of the specimen, the vertical hydraulic pump jack is fixedly connected to the vertical reaction frame of the specimen, the vertical hydraulic pump jack is located directly above the sealing box, the bottom end of the vertical hydraulic pump jack is fixedly connected to a vertical force transmission column, the vertical force transmission column is fixedly connected to a vertical stress and displacement sensor, the bottom end of the vertical force transmission column is fixedly connected to a vertical force pressure seat, the vertical force pressure seat extends into the sealing box, and the bottom end of the vertical force pressure seat is fixedly connected to a specimen pressure plate.

[0016] Preferably, it also includes a sample preparation mechanism, which includes a sample preparation vertical reaction force frame, which is fixedly connected to the top of the base, and a sample preparation oil pressure pump jack is fixedly connected to the sample preparation vertical reaction force frame, and a sample preparation force transmission column is fixedly connected to the bottom end of the sample preparation oil pressure pump jack, and a sample preparation box is provided below the sample preparation force transmission column, and the sample preparation box is plugged into the top of the base, and a sample preparation pressure plate is provided in the sample preparation box.

[0017] Preferably, the sample preparation box includes four sample preparation box rigid plates, which are fastened together by bolts. A slot is provided at the top of the base, and the sample preparation box rigid plates are plugged into the base through the slot. The four sample preparation box rigid plates form a sample preparation space, and the sample preparation pressure plate is located in the sample preparation space.

[0018] The present invention discloses the following technical effects:

[0019] 1. The present invention organically combines the relative humidity controller device with the direct shear test equipment, which can control the humidity during shearing, and then simulate the strength of crushed stone soil under different humidity environments, and more accurately measure the shear strength.

[0020] 2. The present invention solves the problem of sample volume shrinking during dehumidification, causing it to fall out of the shear box, making the experimental results more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 It is a front view of a gravel soil direct shear apparatus with a controlled humidity environment;

[0023] Figure 2 A top view of a gravel soil direct shear apparatus with a controlled humidity environment;

[0024] Figure 3 A side view of a gravel soil direct shear apparatus with a controlled humidity environment;

[0025] Figure 4 is a top view of the upper shear box;

[0026] Figure 5 is a top view of the lower shear box;

[0027] Figure 6 is the front view of the lower shear box;

[0028] Figure 7 are the front view and top view of the retractable rigid plate;

[0029] Figure 8 is an axonometric view of a non-stretchable rigid plate;

[0030] Figure 9 It is the main view, top view and side view of the sample preparation mechanism;

[0031] Figure 10 It is a top view of the sample preparation box;

[0032] Among them, 1. relative humidity controller; 2. base; 3. valve; 4. air inlet pipe; 5. vertical force transmission column; 6. vertical reaction force frame of specimen; 7. vertical hydraulic pump jack; 8. vertical stress and displacement sensor; 9. vertical force pressure seat; 10. sealing box; 11. humidity sensor; 12. exhaust port; 13. electric control thruster; 14. horizontal force transmission rod; 15. slide; 16. shear adjustment gasket; 17. lower shear box; 18. upper shear box; 19. Specimen pressure plate; 20. CNC electric hydraulic jack; 21. Horizontal stress and displacement sensor; 22. Non-retractable rigid plate; 23. Retractable rigid plate; 24. Slide plate; 25. Pressure sensing electrode; 26. Telescopic block; 27. Fixed block; 28. Rigid plate of sample box; 29. Sample pressure plate; 30. Sample hydraulic pump jack; 31. Sample force transmission column; 32. Sample vertical reaction frame; 33. Bolt; 34. Shear force transmission rod; 35. Bottom plate. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiment is only an embodiment of one mechanism of the present invention, not an embodiment of the entire mechanism. All other embodiments derived by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] The present invention provides a gravel soil direct shear apparatus with a controllable humidity environment, comprising:

[0036] Base 2;

[0037] Humidity regulating mechanism, the humidity regulating mechanism is fixedly connected to the top of the base 2;

[0038] The sample shearing mechanism includes an upper shearing portion and a lower shearing portion. Both the upper shearing portion and the lower shearing portion are mounted on the humidity regulating mechanism. The upper shearing portion is located above the lower shearing portion. A shearing gap adjustment gasket 16 is provided between the upper shearing portion and the lower shearing portion. The lower shearing portion is in sliding contact with the bottom end of the humidity regulating mechanism.

[0039] The loading mechanism includes a vertical loading part and a horizontal loading part. The vertical loading part is fixed to the top of the base 2, the vertical loading part is located above the humidity adjustment mechanism, the end of the vertical loading part extends into the humidity adjustment mechanism, the horizontal loading part is fixed to the humidity adjustment mechanism, and the horizontal loading part is fixed to the lower shearing part.

[0040] Furthermore, the humidity adjustment mechanism includes a relative humidity controller 1 and a sealed box 10, which are both fixedly connected to the top of the base 2. The air inlet pipe 4 is fixedly connected to the outer wall of the top of the sealed box 10, and the relative humidity controller 1 is connected to the sealed box 10 through the air inlet pipe 4. The exhaust port 12 is fixedly connected to the outer wall of the bottom of the sealed box 10, and the exhaust port 12 is connected to the sealed box 10. Valves 3 are installed on the air inlet pipe 4 and the exhaust port 12. A humidity sensor 11 is fixedly connected to the inner wall of the top of the sealed box 10, and the upper shearing part, the lower shearing part and the horizontal loading part are all installed on the sealed box 10. The inner wall of the bottom end of the sealed box 10 is fixedly connected to a slide 15, and the lower shearing part is slidably connected to the sealed box 10 through the slide 15. The vertical loading part is located directly above the sealed box 10, and the end of the vertical loading part extends into the sealed box 10.

[0041] Furthermore, the upper shearing part includes an upper shearing box 18, which is located in the sealing box 10, and the upper shearing box 18 is located above the lower shearing part. A shearing adjustment gasket 16 is arranged between the upper shearing box 18 and the lower shearing part. The inner wall of the upper shearing box 18 is fixedly connected to a pressure sensing electric sheet 25, and the outer side of the upper shearing box 18 is fixedly connected to a horizontal force transmission rod 14, and the end of the horizontal force transmission rod 14 is fixedly connected to the movable end of the electric-controlled thruster 13, and the fixed end of the electric-controlled thruster 13 is fixedly connected to the sealing box 10.

[0042] Furthermore, the lower shearing part includes a lower shearing box 17 and a slide 24. The lower shearing box 17 and the slide 24 are both located in the sealing box 10. The slide 24 is fixedly connected to the horizontal loading part. The slide 24 is placed on the slide 15 and is slidably connected to the bottom end of the sealing box 10 through the slide 15. A groove is provided at the top of the slide 24, and a bottom plate 35 is inserted into the groove. A number of channels are correspondingly provided on the slide 24 and the bottom plate 35. The lower shearing box 17 is located above the slide 24. The inner side of the lower shearing box 17 is fixedly connected to the pressure sensing electrode 25. The outer side of the lower shearing box 17 is fixedly connected to the horizontal force transmission rod 14. The end of the horizontal force transmission rod 14 is fixedly connected to the movable end of the electric control propeller 13. The fixed end of the electric control propeller 13 is fixedly connected to the top of the slide 24. The upper shearing box 18 is located above the lower shearing box 17. A shearing adjustment gasket 16 is provided between the upper shearing box 18 and the lower shearing box 17.

[0043] Furthermore, the upper shear box 18 and the lower shear box 17 both include two inextensible rigid plates 22 and two extensible rigid plates 23, and through holes are opened on the two inextensible rigid plates 22 and the two extensible rigid plates 23. The two inextensible rigid plates 22 and the two extensible rigid plates 23 are both located between the two inextensible rigid plates 22, and the two inextensible rigid plates 22 and the two extensible rigid plates 23 form a rectangular structure. The inner sides of the two inextensible rigid plates 22 and the two extensible rigid plates 23 are fixed with pressure sensing electrodes 25, and the outer sides of the two inextensible rigid plates 22 and the two extensible rigid plates 23 are fixed with horizontal force transmission rods 14. A shear seam adjustment gasket 16 is provided between the inextensible rigid plate 22 of the upper shear box 18 and the inextensible rigid plate 22 corresponding to the lower shear box 17, and a shear seam adjustment gasket 16 is provided between the extensible rigid plate 23 of the upper shear box 18 and the extensible rigid plate 23 corresponding to the lower shear box 17.

[0044] The retractable rigid plate 23 and the non-retractable rigid plate 22 symmetrically form the upper shear box 18 and the lower shear box 17, ensuring that the upper shear box 18 and the lower shear box 17 can move, solving the problem of the sample escaping from the shear box due to the shrinkage of the sample volume during dehumidification.

[0045] Pressure sensing electrodes 25 are attached to both the retractable rigid plate 23 and the non-retractable rigid plate 22 and are connected to the system outside the sealed box 10 via wires, which can be used to determine whether the retractable rigid plate 23 and the non-retractable rigid plate 22 are in contact with the sample.

[0046] Furthermore, a bottom plate 35 is fixedly embedded on the top of the slide plate 24 , and a plurality of holes are correspondingly opened on the bottom plate 35 and the slide plate 24 .

[0047] Furthermore, the retractable rigid plate 23 includes a fixed block 27 and a retractable block 26. The retractable blocks 26 are slidably connected on both sides of the fixed block 27. A number of through holes are provided on the fixed block 27 and the retractable block 26. The pressure sensing electrode 25 is fixedly connected to the fixed block 27, and the horizontal force transmission rod 14 is fixedly connected to the fixed block 27.

[0048] Furthermore, the horizontal loading part includes a CNC electric hydraulic jack 20, which is fixed to the outer wall of the sealing box 10. The movable end of the CNC electric hydraulic jack 20 is fixed with a shear force transmission rod 34. The end of the shear force transmission rod 34 extends into the sealing box 10 and is fixed with the slide 24. The shear force transmission rod 34 is fixed with a horizontal stress and displacement sensor 21.

[0049] Furthermore, the vertical loading part includes a vertical hydraulic pump jack 7, a sample vertical reaction frame 6 is fixedly connected to the top of the base 2, the vertical hydraulic pump jack 7 is fixedly connected to the sample vertical reaction frame 6, the vertical hydraulic pump jack 7 is located directly above the sealing box 10, the bottom end of the vertical hydraulic pump jack is fixedly connected to a vertical force transmission column 5, the vertical force transmission column 5 is fixedly connected to a vertical stress and displacement sensor 8, the bottom end of the vertical force transmission column 5 is fixedly connected to a vertical force pressure seat 9, the vertical force pressure seat 9 extends into the sealing box 10, and the bottom end of the vertical force pressure seat 9 is fixedly connected to a sample pressure plate 19.

[0050] Furthermore, it also includes a sample preparation mechanism, which includes a sample preparation vertical reaction force frame 32, which is fixedly connected to the top of the base 2, and a sample preparation oil pressure pump jack 30 is fixedly connected to the sample preparation vertical reaction force frame 32, and a sample preparation force transmission column 31 is fixedly connected to the bottom end of the sample preparation oil pressure pump jack 30, and a sample preparation box is provided below the sample preparation force transmission column 31, and the sample preparation box is plugged into the top of the base 2, and a sample preparation pressure plate 29 is provided in the sample preparation box.

[0051] Furthermore, the sample preparation box includes four sample preparation box rigid plates 28, which are fastened together by bolts 33. A slot is provided at the top of the base 2, and the sample preparation box rigid plates 28 are plugged into the base 2 through the slot. The four sample preparation box rigid plates 28 form a sample preparation space, and the sample preparation pressure plate 29 is located in the sample preparation space.

[0052] When using the gravel soil direct shear apparatus with controllable humidity environment provided by the present invention, the operating steps are as follows:

[0053] 1. Sample Preparation: Insert the rigid plates of the sample preparation box into the slots of the base 2 and secure the rigid plates 28 of the sample preparation box with bolts 33. Based on the test objectives, place a certain amount of test gravel soil into the sample preparation box. Turn on the sample preparation hydraulic pump jack 30 to apply pressure to the gravel soil to prepare the sample. After the sample is pressed, disassemble the rigid plates 28 of the sample preparation box and remove the sample.

[0054] 2. Sample installation: Adjust the upper shear box 18 and the lower shear box 17, put the sample into the space formed by the upper shear box 18 and the lower shear box 17, then turn on the electric propeller 13, let the retractable rigid plate 23 and the non-retractable rigid plate 22 be in close contact with the sample, when the system senses that the retractable rigid plate 23 and the non-retractable rigid plate 22 are in close contact with the sample through the pressure sensing electrode 25, stop applying pressure, install the top cover of the sealing box 10, and ensure the airtightness of the sealing box 10.

[0055] 3. Control humidity: Open the relative humidity controller 1, and deliver the generated moisture from the air inlet pipe 4 into the sealed box 10. At the same time, open the exhaust port 12 to discharge the original air inside. When the humidity sensor 11 senses that the target humidity in the sealed box 10 has been reached, close the air inlet pipe 4 and the exhaust port 12, and at the same time, close the relative humidity controller 1.

[0056] 4. Apply consolidation pressure: When the sample is dehumidified, check whether the retractable rigid plate 23 and the non-retractable rigid plate 22 are in contact with the sample. If not, apply force to make the retractable rigid plate 23 and the non-retractable rigid plate 22 contact the sample; open the vertical hydraulic pump jack 7 to apply consolidation pressure until the predetermined consolidation pressure is loaded. The vertical stress and displacement sensor 8 can display the value in real time. When in use, ensure that the center of gravity of the vertical force transmission column 5 is vertical.

[0057] 5. Apply shear stress: The CNC electric hydraulic jack 20 applies shear stress to the specimen through the shear force transmission column. The loading rate can be controlled to achieve fast shear and slow shear. The horizontal stress and displacement sensor 21 displays the shear stress and displacement in real time.

[0058] 6. Data acquisition and processing: Obtain shear stress and displacement data on the horizontal stress and displacement sensor. Draw a shear stress-shear displacement relationship curve with shear stress as the ordinate and shear displacement as the abscissa. Select the peak point or stable value on the relationship curve as the shear strength. Draw a relationship curve with shear strength as the ordinate and vertical pressure as the abscissa. Draw a curve based on each point on the graph to obtain the internal friction angle and cohesion.

[0059] Working principle of the gravel soil direct shear apparatus with controlled humidity environment:

[0060] A sealed box 10 capable of retaining moisture is set up, a humidity sensor 11 and an external relative humidity controller 1 are installed in the sealed box 10, and after the sample is installed in the space formed by the upper shear box 18 and the lower shear box 17, the sealed box 10 is sealed; the relative humidity controller 1 is turned on, and the valve 3 is opened to deliver humid air. When the humidity sensor 11 measures that the humidity in the sealed box 10 reaches the target humidity, the valve 3 is closed; a shear test is performed on the sample after applying vertical pressure; during the shear test, the shear rate is controlled by using a gearbox according to different requirements. Generally, four different vertical pressures are used in each group, and the horizontal stress and strain curve and c and φ strength indicators of the sample can be obtained.

[0061] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0062] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A gravel soil direct shear apparatus with a controllable humidity environment, characterized in that: include: Base (2); A humidity regulating mechanism, the humidity regulating mechanism being fixedly connected to the top of the base (2); A sample shearing mechanism, comprising an upper shearing portion and a lower shearing portion, both of which are mounted on the humidity regulating mechanism, the upper shearing portion being located above the lower shearing portion, a shearing adjustment gasket (16) being provided between the upper shearing portion and the lower shearing portion, the lower shearing portion being in sliding connection with the bottom end of the humidity regulating mechanism; the upper shearing portion comprising an upper shearing box (18); and the lower shearing portion comprising a lower shearing box (17); A loading mechanism, the loading mechanism comprising a vertical loading portion and a horizontal loading portion, the vertical loading portion being fixedly connected to the top of the base (2), the vertical loading portion being located above the humidity regulating mechanism, the end of the vertical loading portion extending into the humidity regulating mechanism, the horizontal loading portion being fixedly connected to the humidity regulating mechanism, and the horizontal loading portion being fixedly connected to the lower shearing portion; The humidity control mechanism comprises a relative humidity controller (1) and a sealed box (10), wherein the relative humidity controller (1) and the sealed box (10) are both fixedly connected to the top of the base (2), an air inlet pipe (4) is fixedly connected to the top outer wall of the sealed box (10), and the relative humidity controller (1) is communicated with the sealed box (10) through the air inlet pipe (4), and an exhaust port (12) is fixedly connected to the bottom outer wall of the sealed box (10), and the exhaust port (12) is communicated with the sealed box (10), and the air inlet pipe (4) and The exhaust port (12) is provided with a valve (3), the top inner wall of the sealed box (10) is fixedly connected with a humidity sensor (11), the upper shearing portion, the lower shearing portion and the horizontal loading portion are all installed on the sealed box (10), the bottom inner wall of the sealed box (10) is fixedly connected with a slide (15), the lower shearing portion is slidably connected with the sealed box (10) via the slide (15), the vertical loading portion is located directly above the sealed box (10), and the end of the vertical loading portion extends into the sealed box (10); The upper shear box (18) and the lower shear box (17) each comprise two inelastic rigid plates (22) and two retractable rigid plates (23), both of which are provided with through holes, and both of which are located between the two inelastic rigid plates (22), and which form a rectangular structure with the two inelastic rigid plates (22) and the two retractable rigid plates (23), and which are fixed with compression members on the inner sides of the two inelastic rigid plates (22) and the two retractable rigid plates (23). A force sensing electric sheet (25), the outer sides of the two non-retractable rigid plates (22) and the two retractable rigid plates (23) are fixedly connected with horizontal force transmission rods (14), a shearing seam adjusting gasket (16) is provided between the non-retractable rigid plate (22) of the upper shear box (18) and the non-retractable rigid plate (22) corresponding to the lower shear box (17), and a shearing seam adjusting gasket (16) is provided between the retractable rigid plate (23) of the upper shear box (18) and the retractable rigid plate (23) corresponding to the lower shear box (17); The retractable rigid plate (23) includes a fixed block (27) and a retractable block (26). The retractable blocks (26) are slidably connected to both sides of the fixed block (27). A plurality of through holes are provided on the fixed block (27) and the retractable block (26). The pressure sensing electric sheet (25) is fixedly connected to the fixed block (27). The horizontal force transmission rod (14) is fixedly connected to the fixed block (27).

2. The direct shear apparatus for crushed soil with a controllable humidity environment according to claim 1, characterized in that: The upper shear box (18) is located in the sealing box (10), and the upper shear box (18) is located above the lower shear part. The shear seam adjustment gasket (16) is provided between the upper shear box (18) and the lower shear part. The inner wall of the upper shear box (18) is fixedly connected with a pressure sensing electric sheet (25). The outer side of the upper shear box (18) is fixedly connected with a horizontal force transmission rod (14). The end of the horizontal force transmission rod (14) is fixedly connected with the movable end of the electric control propeller (13), and the fixed end of the electric control propeller (13) is fixedly connected to the sealing box (10).

3. The direct shear apparatus for crushed soil with a controllable humidity environment according to claim 2, characterized in that: The lower shearing portion further comprises a slide plate (24), the lower shearing box (17) and the slide plate (24) are both located in the sealing box (10), the slide plate (24) is fixedly connected to the horizontal loading portion, the slide plate (24) is placed on the slide bar (15) and is slidably connected to the bottom end of the sealing box (10) through the slide bar (15), a groove is provided at the top end of the slide plate (24), a bottom plate (35) is inserted into the groove, a plurality of channels are correspondingly provided on the slide plate (24) and the bottom plate (35), the lower shearing box (17) is located on the slide plate (2 4), the inner side of the lower shear box (17) is fixedly connected with the pressure sensing electric sheet (25), the outer side of the lower shear box (17) is fixedly connected with the horizontal force transmission rod (14), the end of the horizontal force transmission rod (14) is fixedly connected with the movable end of the electric control propeller (13), the fixed end of the electric control propeller (13) is fixedly connected to the top of the slide (24), the upper shear box (18) is located above the lower shear box (17), and the shear seam adjustment gasket (16) is provided between the upper shear box (18) and the lower shear box (17).

4. The direct shear apparatus for crushed soil with a controllable humidity environment according to claim 3, characterized in that: The horizontal loading part includes a numerically controlled electric hydraulic jack (20), the numerically controlled electric hydraulic jack (20) is fixedly connected to the outer wall of the sealing box (10), the movable end of the numerically controlled electric hydraulic jack (20) is fixedly connected to a shear force transmission rod (34), the distal end of the shear force transmission rod (34) extends into the sealing box (10) and is fixedly connected to the slide plate (24), and the shear force transmission rod (34) is fixedly connected to a horizontal stress and displacement sensor (21).

5. The direct shear apparatus for crushed soil with a controllable humidity environment according to claim 1, characterized in that: The vertical loading part includes a vertical hydraulic pump jack (7), the top of the base (2) is fixedly connected to a sample vertical reaction frame (6), the vertical hydraulic pump jack (7) is fixedly connected to the sample vertical reaction frame (6), the vertical hydraulic pump jack (7) is located directly above the sealing box (10), the bottom end of the vertical hydraulic pump jack (7) is fixedly connected to a vertical force transmission column (5), the vertical force transmission column (5) is fixedly connected to a vertical stress and displacement sensor (8), the bottom end of the vertical force transmission column (5) is fixedly connected to a vertical force pressure seat (9), the vertical force pressure seat (9) extends into the sealing box (10), and the bottom end of the vertical force pressure seat (9) is fixedly connected to a sample pressure plate (19).

6. The direct shear apparatus for crushed soil with a controllable humidity environment according to claim 1, characterized in that: The invention also includes a sample preparation mechanism, wherein the sample preparation mechanism includes a sample preparation vertical reaction force frame (32), the sample preparation vertical reaction force frame (32) is fixedly connected to the top of the base (2), a sample preparation oil pressure pump jack (30) is fixedly connected to the sample preparation vertical reaction force frame (32), a sample preparation force transmission column (31) is fixedly connected to the bottom end of the sample preparation oil pressure pump jack (30), a sample preparation box is arranged below the sample preparation force transmission column (31), the sample preparation box is plugged into the top of the base (2), and a sample preparation pressure plate (29) is arranged in the sample preparation box.

7. The direct shear apparatus for crushed soil with a controllable humidity environment according to claim 6, characterized in that: The sample preparation box comprises four sample preparation box rigid plates (28), the four sample preparation box rigid plates (28) are fastened together by bolts (33), a slot is provided at the top of the base (2), the sample preparation box rigid plates (28) are plugged into the base (2) through the slot, the four sample preparation box rigid plates (28) form a sample preparation space, and the sample preparation pressure plate (29) is located in the sample preparation space.

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