Soil body shearing device for testing dynamic performance of deep-sea sedimentary soil and test method

Abstract

The invention belongs to the technical field of rock and soil mass mechanical tests, and particularly discloses a soil mass shearing device for testing the dynamic performance of deep-sea sedimentary soil and a test method. The invention discloses a soil body shearing device for testing the dynamic performance of deep-sea sedimentary soil. The soil body shearing device comprises a counter-force frame, a supporting assembly, a pressing assembly and a multidirectional loading assembly, the supporting assembly is slidably arranged on the counter-force frame, the test piece is located between the supporting assembly and the pressing assembly, the Z-direction loading piece is located on the top face of the pressing assembly, loads are applied to the test piece through the pressing assembly, and the X-direction loading piece and the Y-direction loading piece make contact with the side faces of the supporting assembly correspondingly, so that the loads are applied to the supporting assembly; therefore, the test piece can bear shear loads in the normal direction and the horizontal direction at the same time, the loading condition is closer to the earthquake action borne by an actual engineering site, the shear stress can be directly applied, the generated shear strain can be directly measured, and the problem that the dynamic performance of deep sea sedimentary soil cannot be conveniently tested at present is solved.

Description

Technical Field

[0001] The invention patent relates to the technical field of rock and soil mechanics testing, and specifically to a soil shearing device and test method for dynamic performance testing of deep-sea sedimentary soil. Background Art

[0002] As an important transportation infrastructure connecting different islands and regions, cross-sea bridge construction is gradually becoming an important transportation hub worldwide. The construction of cross-sea bridges faces complex ocean, geological and climatic challenges, especially engineering problems under deep-sea sedimentary soil conditions, which brings severe technical tests to infrastructure construction.

[0003] In the Pacific Rim seismic belt, the geological structure is active and the marine environment is unique. Deep-sea sedimentary soil is one of the important geotechnical materials in the region. Deep-sea sedimentary soil is usually composed of a mixture of sand, clay, silt and gravel, and is highly heterogeneous and variable. Due to the influence of sedimentation and the marine environment, the physical and mechanical properties of these soils (such as density, porosity, friction angle, compressibility, etc.) often vary greatly, and under the dynamic effects of seismic loads, marine climate change, etc., their mechanical behavior shows strong nonlinear and time-varying characteristics. These characteristics make the stability of deep-sea sedimentary soil a key issue in the construction of cross-sea bridges, especially in terms of bridge foundation design, settlement control, and seismic design.

[0004] In order to cope with these complex characteristics of deep-sea sedimentary soil, it is particularly important to accurately evaluate its geotechnical mechanical properties. Traditional static soil testing methods cannot fully reveal the response of soil under dynamic loads. Therefore, it is urgent to develop dynamic performance testing equipment that can simulate the behavior of deep-sea sedimentary soil under real working conditions. To this end, designing a high-precision, controllable soil shear device that can accurately evaluate the dynamic mechanical properties of deep-sea sedimentary soil under simulated marine environment, seismic loads and different temperature and humidity conditions, and provide reliable data support for the foundation design of cross-sea bridges, is a technical problem that needs to be solved urgently in the current field of geotechnical engineering testing.

[0005] Simulating the natural stress state of soil through geotechnical testing instruments and then studying the strength and deformation characteristics of soil under actual load conditions is an important basis for guiding and solving practical engineering problems. At present, the main instruments for testing the dynamic characteristics of soil include dynamic triaxial apparatuses, dynamic torsional shear apparatuses, and dynamic simple shear apparatuses. The dynamic triaxial apparatus cannot simulate the rotation of the principal stress axes under the action of pseudo-dynamic loads; the dynamic torsional shear apparatus applies vertical loads and horizontal reciprocating torsional shear actions simultaneously on a hollow cylindrical specimen, which can be used to study the constitutive relationship of soil under complex stress conditions, but has disadvantages such as difficulty in forming the hollow cylindrical specimen and uneven shear strain; the dynamic simple shear apparatus can apply vertical and horizontal shear loads to the specimen simultaneously, and its loading conditions are closer to the seismic actions received by actual engineering sites. The shear stress can be directly applied, and the generated shear strain can be directly measured. The dynamic simple shear apparatus has significant advantages that other instruments do not have in simulating seismic actions. Therefore, there is a problem in the prior art that it is inconvenient to conduct dynamic performance tests on deep-sea sedimentary soil.

[0006] Content of the invention patent

[0007] The purpose of this invention patent is to provide a soil shear device and test method for dynamic performance testing of deep-sea sedimentary soil to solve the problem in the prior art that it is inconvenient to conduct dynamic performance tests on deep-sea sedimentary soil.

[0008] The technical solution of this invention patent to solve the above technical problems is as follows:

[0009] A soil shear device for dynamic performance testing of deep-sea sedimentary soil, comprising: a reaction frame, a support assembly, a pressing assembly, and a multi-directional loading assembly;

[0010] The support assembly is slidably arranged on the reaction frame, a specimen is placed above the support assembly, and the pressing assembly is in contact with the top surface of the specimen;

[0011] The multi-directional loading assembly includes: a Z-direction loading member in contact with the top surface of the pressing assembly and a Y-direction loading member and a Z-direction loading member respectively in contact with the support assembly, and the extending direction of the X-direction loading member is perpendicular to the extending direction of the Y-direction loading member.

[0012] The support assembly is slidably arranged on the reaction frame of this invention patent, the specimen is located between the support assembly and the pressing assembly, the Z-direction loading member is located on the top surface of the pressing assembly, a load is applied to the specimen through the pressing assembly, the X-direction loading member and the Y-direction loading member are respectively in contact with the side surface of the support assembly, so as to apply a load to the support assembly, so that the specimen simultaneously bears normal and horizontal shear loads, the loading conditions are closer to the seismic actions received by actual engineering sites, the shear stress can be directly applied, and the generated shear strain can be directly measured, thereby solving the problem in the prior art that it is inconvenient to conduct dynamic performance tests on deep-sea sedimentary soil.

[0013] Preferably, a rigid constraint ring is provided between the lower base of the support assembly and the upper pressing head of the pressing assembly, and the rigid constraint ring is sleeved outside the test piece.

[0014] This invention patent sets a rigid constraint ring to rigidly limit the cross-section of the test piece, so that the cross-section of the test piece remains unchanged during the test, thus avoiding test errors caused by cross-section changes.

[0015] Preferably, the support assembly includes: a bearing plate slidably matched with the reaction frame, a base provided above the bearing plate, and a lower base located above the base. The top surface of the lower base contacts the test piece, and the outer walls of the base contact the X-direction loading member and the Y-direction loading member respectively.

[0016] The base of this invention patent contacts the X-direction loading member and the Y-direction loading member. A bearing plate is provided at its bottom to bear pressure, and a lower base is provided at the top to contact the test piece, so that when the position of the base changes, a shear force can be applied to the bottom of the test piece through the lower base.

[0017] Preferably, a plurality of rollers are connected to the bottom surface of the bearing plate, and rolling grooves are provided on the reaction frame for rolling cooperation with the rollers.

[0018] This invention patent enables the bearing plate to drive the base to move along the rolling groove through the rolling cooperation of the rollers and the rolling grooves, facilitating the simulation of the shear force generated during an actual earthquake.

[0019] Preferably, a lower O-ring is also provided between the lower base and the test piece, and the lower base is provided with a lower drain hole communicating with the test piece.

[0020] This invention patent sets a lower O-ring to ensure the sealing between the test piece and the lower base, and the lower drain hole is used to conveniently drain the liquid water generated by the test piece of deep-sea sediment during the test.

[0021] Preferably, the pressing assembly includes: an upper pressing head located above the test piece and an upper O-ring provided between the test piece and the upper pressing head. The top surface of the upper pressing head contacts the Z-direction loading member.

[0022] The Z-direction loading member of this invention patent applies a load to the upper pressing head to squeeze the top of the test piece, and the upper O-ring is used to ensure the sealing between the upper pressing head and the test piece.

[0023] Preferably, the upper pressing head is provided with an upper drain hole communicating with the test piece.

[0024] This invention patent conveniently drains the liquid water generated when the top of the test piece is loaded by opening the upper drain hole.

[0025] Preferably, permeable stones are respectively provided on the top surface and the bottom surface of the test piece.

[0026] In this invention patent, by providing a permeable stone, it can not only protect the test piece to a certain extent, but also facilitate the water generated by the deep-sea sediment soil test piece to pass through and drain out.

[0027] Furthermore, the above-mentioned X-direction loading member includes: an X-direction power cylinder connected to the reaction frame and an X-direction connecting plate provided at the end of the X-direction power cylinder; the Y-direction loading member includes: a Y-direction power cylinder connected to the reaction frame and a Y-direction connecting plate provided at the end of the Y-direction power cylinder, and the X-direction connecting plate and the Y-direction connecting plate are respectively connected to the support assembly; the Z-direction loading member includes: a Z-direction power cylinder connected to the reaction frame and a Z-direction connecting plate provided at the end of the Z-direction power cylinder, and the Z-direction connecting plate is connected to the pressing assembly.

[0028] In this invention patent, each loading member is driven by a power cylinder, and the piston rod of the power cylinder is connected to the pressing assembly or the support assembly through a connecting plate, so as to realize the application and transmission of the load.

[0029] Preferably, a temperature control system is provided between the reaction frame and the test piece. The temperature control system includes: a heat insulation cover located outside the test piece, a cooler provided on the inner side wall of the heat insulation cover, an exhaust valve and a temperature sensor respectively located on the top wall of the heat insulation cover. The heat insulation cover is in sealing cooperation with the base of the support assembly, a cold liquid cavity is formed inside the heat insulation cover, the Z-direction loading member penetrates through the top wall of the heat insulation cover, and a liquid injection pipeline is connected to the bottom of the heat insulation cover. The liquid injection pipeline penetrates into the side wall of the base and then penetrates out from the top surface of the base, so as to communicate with the cold liquid cavity.

[0030] In this invention patent, by providing a temperature control system, a sealed cold liquid cavity is provided between the heat insulation cover and the test piece, the inlet and outlet of the cooling liquid are controlled through the liquid injection pipeline, and the cooler is used to keep the test piece warm and insulated, so that the test piece remains in the deep-sea sediment soil state, thus avoiding the influence of the change of the test piece state on the test results during the test process.

[0031] Another aspect of the invention, the present invention also provides the following technical solution: a test method for a soil shear device for testing the dynamic properties of deep-sea sediment soil, including the following steps:

[0032] S1. Preparation and installation of the test piece: Take an appropriate amount of deep-sea sediment soil sample, prepare a test piece according to the dimensions required by the test. The shape of the test piece is cylindrical, and the upper surface of the test piece is flat to ensure uniform stress during loading;

[0033] Place the test piece on the lower base, ensure that the position of the test piece is horizontal, and permeable stones are respectively placed on the upper and lower sides of the test piece so that the liquid water can drain smoothly during the test;

[0034] Then, apply pressure through the upper pressure head to ensure that the test piece is in the correct position inside the test device;

[0035] S2. Temperature control: Turn on the temperature control system, set the temperature required for the test, inject an appropriate amount of coolant into the cold liquid cavity, and start the refrigerator. Monitor through the temperature sensor and ensure that the temperature of the specimen is maintained within the set range.

[0036] S3. Loading process: Apply an initial load to the specimen through the multi-directional loading component; start the Z-direction power cylinder to make the pressing component act on the upper part of the specimen, and apply vertical pressure through the upper pressing head to ensure that the specimen does not displace or deform during the loading process.

[0037] Gradually increase the loads in the X, Y, and Z directions to simulate seismic or wave actions in different directions, and investigate the dynamic responses of deep-sea sedimentary soil under different loading directions.

[0038] S4. Shear test and dynamic response monitoring: Use sensors to monitor the shear strain, pore water pressure, and deformation degree of the specimen, and record its dynamic response.

[0039] Collect the outflow volume of liquid water from the specimen during the loading process through the upper and lower drainage holes in the device to evaluate the water discharge of the soil under dynamic loads.

[0040] S5. End of shear test and data recording: When the shear deformation of the specimen reaches the predetermined maximum limit, or the liquid water discharge reaches the set standard, stop loading and complete the test.

[0041] Record all key data, including load changes, stress-strain curves, pore water pressure changes, liquid water discharge volume, and the final deformation of the specimen.

[0042] The present invention of the invention patent has the following beneficial effects:

[0043] (1) A support component is slidably arranged on the reaction frame of the present invention of the invention patent. The specimen is located between the support component and the pressing component. The Z-direction loading member is located on the top surface of the pressing component, and a load is applied to the specimen through the pressing component. The X-direction loading member and the Y-direction loading member are respectively in contact with the side surfaces of the support component, so as to apply a load to the support component, so that the specimen simultaneously bears normal and horizontal shear loads. The loading conditions are closer to the seismic actions received by the actual engineering site. The shear stress can be directly applied, and the generated shear strain can be directly measured, thus solving the problem that it is inconvenient to test the dynamic performance of deep-sea sedimentary soil in the prior art.

[0044] (2) The present invention of the invention patent rigidly limits the cross-section of the specimen by setting a rigid constraint ring, so that the cross-section of the specimen remains unchanged during the test, thereby avoiding test errors caused by cross-section changes.

[0045] (3) By setting up a temperature control system, a sealed cold liquid cavity is arranged between the heat insulation cover and the test piece. The inflow and outflow of the cooling liquid are controlled through the liquid injection pipeline, and the test piece is heat-insulated in cooperation with the refrigerator, so that the test piece maintains the state of deep-sea sediment soil, thereby avoiding the influence of the change of the test piece state on the test results during the test. Brief Description of the Drawings

[0046] Figure 1 It is a schematic structural diagram of the soil shear device for testing the dynamic properties of deep-sea sediment soil of the present invention patent;

[0047] Figure 2 It is a half-sectional view between the upper pressure head and the lower base of the present invention patent;

[0048] Figure 3 It is a schematic structural diagram of the temperature control system of the present invention patent;

[0049] In the figure: 10 - reaction frame; 11 - rolling groove; 20 - support assembly; 21 - bearing plate; 22 - base; 23 - lower base; 24 - roller; 25 - lower O-ring; 26 - lower drain hole; 30 - pressing assembly; 31 - upper pressure head; 32 - upper O-ring; 33 - upper drain hole; 40 - multi-directional loading assembly; 41 - X-direction loading member; 42 - Y-direction loading member; 43 - Z-direction loading member; 44 - X-direction power cylinder; 45 - X-direction connecting plate; 46 - Y-direction power cylinder; 47 - Y-direction connecting plate; 48 - Z-direction power cylinder; 49 - Z-direction connecting plate; 51 - permeable stone; 60 - rigid restraint ring; 70 - temperature control system; 71 - heat insulation cover; 72 - refrigerator; 73 - exhaust valve; 74 - temperature sensor; 75 - cold liquid cavity; 76 - liquid injection pipeline; 77 - waterproof bearing; 78 - heat insulation asbestos. Detailed Embodiments

[0050] Next, the technical solutions in the embodiments of the present invention patent will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention patent. It should be understood that the following drawings only show some embodiments of the present invention patent, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention patent, rather than all the embodiments. Based on the embodiments in the present invention patent, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope protected by the present invention patent.

[0051] Embodiment

[0052] Refer to Figure 1, A soil shear device for testing the dynamic properties of deep - sea sedimentary soil, comprising: a reaction frame 10, a support assembly 20, a pressing assembly 30, and a multi - directional loading assembly 40. The reaction frame 10 is in a square - shaped opening form, and a rolling groove 11 is provided on the inner wall of its bottom. The support assembly 20 can slide along the rolling groove 11, facilitating the adjustment of the horizontal position of the support assembly 20.

[0053] Refer to Figure 1 and Figure 2 , The support assembly 20 includes: a bearing plate 21 slidably engaged with the reaction frame 10, a base 22 disposed above the bearing plate 21, and a lower base 23 located above the base 22. A plurality of rollers 24 that are in rolling engagement with the rolling groove 11 are connected to the bottom surface of the bearing plate 21, enabling the rollers 24 to roll along the rolling groove 11, thereby driving the bearing plate 21 to move. The outer wall of the base 22 is connected to some components in the multi - directional loading assembly 40, and the upper part of the lower base 23 is used to place the deep - sea sedimentary soil specimen for the test.

[0054] A lower O - ring 25 is also provided between the lower base 23 and the specimen. The lower O - ring 25 is made of rubber and is used to seal the gap between the specimen and the lower base 23, preventing the leakage of the liquid water generated during the test of the deep - sea sedimentary soil specimen. A lower drainage hole 26 communicating with the specimen is also opened on the lower base 23. The lower drainage hole 26 is used to orderly drain the liquid water generated by the specimen during the test. The dynamic state of the specimen can be determined by statistically analyzing the volume of the drained liquid water.

[0055] The pressing assembly 30 is located on the top surface of the specimen and includes: an upper pressing head 31 in contact with the top surface of the specimen and an upper O - ring 32 disposed between the specimen and the upper pressing head 31. The top surface of the upper pressing head 31 is in contact with some components in the multi - directional loading assembly 40. The upper O - ring 32 is also made of rubber and is used to seal the gap between the specimen and the upper pressing head 31, preventing the leakage of the liquid water generated during the test of the deep - sea sedimentary soil specimen. An upper drainage hole 33 communicating with the specimen is also opened on the upper pressing head 31. The upper drainage hole 33 is used to orderly drain the liquid water generated by the specimen during the test. The dynamic state of the specimen can be determined by statistically analyzing the volume of the drained liquid water.

[0056] The multi-directional loading assembly 40 includes a Z-direction loading member 43 connected to the top surface of the upper platen 31, an X-direction loading member 41 and a Y-direction loading member 42 respectively connected to different side surfaces of the base 22, and the extending directions of the X-direction loading member 41 and the Y-direction loading member 42 are perpendicular to each other. The X-direction loading member 41 includes an X-direction power cylinder 44 connected to the reaction frame 10 and an X-direction connecting plate 45 provided at the end of the X-direction power cylinder 44, and the X-direction connecting plate 45 is connected to the outer side wall of the base 22; the Y-direction loading member 42 includes a Y-direction power cylinder 46 connected to the reaction frame 10 and a Y-direction connecting plate 47 provided at the end of the Y-direction power cylinder 46, and the Y-direction connecting plate 47 is connected to the other outer side wall of the base 22. The X-direction loading member 41 and the Y-direction loading member 42 are at the same horizontal height, applying loads in different directions to the base 22, causing the base 22 to displace along the rolling groove 11, thereby generating a shear force on the bottom of the upper specimen.

[0057] The Z-direction loading member 43 includes a Z-direction power cylinder 48 connected to the reaction frame 10 and a Z-direction connecting plate 49 provided at the end of the Z-direction power cylinder 48, and the Z-direction connecting plate 49 is connected to the top surface of the upper platen 31. The Z-direction power cylinder 48 provides power to apply a load to the top of the specimen through the upper platen 31 to compress the specimen, thereby causing corresponding deformation at the bottom of the specimen.

[0058] The specimen is deep-sea sediment soil. During the test, the specimen is placed between the upper platen 31 and the lower base 23, and water-permeable stones 51 are provided on both the top and bottom surfaces of the specimen. The surface of the water-permeable stone 51 in contact with the specimen is a frosted surface, which can not only protect the specimen but also facilitate the liquid water generated during the test to pass through the water-permeable stone 51 and enter the upper drainage hole 33 and the lower drainage hole 26. A rigid restraint ring 60 is also sleeved outside the specimen. The rigid restraint ring 60 is located between the upper platen 31 and the lower base 23 and is used to restrain and limit the specimen, so that the cross-section of the specimen remains unchanged during the test, thereby avoiding test errors caused by cross-section changes.

[0059] Refer to Figure 3, a temperature control system 70 can also be provided between the outer side of the test piece and the inner wall of the reaction frame 10. The temperature control system 70 includes: a heat insulation cover 71 located on the outer side of the test piece, a cooler 72 provided on the inner side wall of the heat insulation cover 71, and an exhaust valve 73 and a temperature sensor 74 respectively located on the top wall of the heat insulation cover 71. The heat insulation cover 71 and the base 22 are in sealing fit, so that a cold liquid cavity 75 is formed inside the heat insulation cover 71. The bottom of the heat insulation cover 71 is also connected with a liquid injection pipeline 76. The liquid injection pipeline 76 penetrates into the side wall of the base 22 and then penetrates out from the top surface of the base 22, so as to communicate with the cold liquid cavity 75, facilitating the inflow and outflow of the cooling liquid. The number of the coolers 72 is multiple and they are evenly distributed on the side wall of the heat insulation cover 71, so as to avoid temperature differences at different positions of the cold liquid cavity 75. The Z-direction power cylinder 48 penetrates the top wall of the heat insulation cover 71, and a waterproof bearing 77 is provided at the penetration position. The outer wall of the heat insulation cover 71 is also provided with heat insulation asbestos 78, so as to further insulate and heat the cold liquid cavity 75. By providing the temperature control system 70, the present invention facilitates heat insulation of the test piece, keeps the test piece in the state of deep sea sediment soil, and thus avoids the influence of the change of the state of the test piece during the test on the test result.

[0060] The operation process of the present invention for patent: 1) The multi-directional loading assembly 40 applies a load; 2) The upper platen 31 compresses the test piece; 3) The base 22 displaces along the rolling groove 11 and applies a shear force to the bottom of the test piece; 4) The bottom of the test piece deforms and liquid water flows out through the upper drainage hole 33 and the lower drainage hole 26 respectively.

[0061] A test method for a soil shear device for testing the dynamic properties of deep sea sediment soil includes the following steps:

[0062] 1. Test piece preparation and device setting

[0063] Test piece preparation: Take an appropriate amount of deep sea sediment soil sample and prepare a test piece according to the dimensions required by the test. The size and shape of the test piece should meet the accommodation conditions of the device, usually in a cylindrical shape. The upper surface of the test piece should be flat to ensure uniform stress during loading.

[0064] Device installation: Place the test piece on the lower base 23 and ensure that the position of the test piece is horizontal. Permeable stones (51) should be placed on both the upper and lower sides of the test piece so that liquid water can drain smoothly during the test. Then, apply pressure through the upper platen 31 to ensure that the test piece is in the correct position inside the test device.

[0065] 2. Temperature regulation and system initialization

[0066] Turn on the temperature control system 70 and set the temperature required for the test, usually set according to the temperature of the deep - sea environment. Inject an appropriate amount of coolant into the cold liquid cavity 75 and start the cooler 72. Monitor through the temperature sensor 74 and ensure that the temperature of the test piece is maintained within the set range (for example, usually set to the deep - sea temperature between 4°C and 25°C).

[0067] Ensure that all systems in the device (such as the multi - directional loading component, the pressing component, the drainage system) are in working condition to ensure the smooth progress of the test.

[0068] 3. Loading process

[0069] Initial loading: Apply an initial load to the test piece through the multi - directional loading component 40. The loading members (41, 42, 43) in the X, Y, and Z directions apply preliminary loads through the power cylinders respectively. The loads in the X and Y directions are mainly used to simulate the horizontal loads, while the load in the Z direction is used to simulate the vertical load.

[0070] Pressing loading: Start the Z - direction power cylinder 48 to make the pressing component 30 act on the upper part of the test piece, and apply a vertical pressure through the upper pressing head 31 to ensure that the test piece does not displace or deform during the loading process.

[0071] Multi - directional shear loading: Gradually increase the loads in the X, Y, and Z directions to simulate the seismic or wave actions in different directions and investigate the dynamic response of deep - sea sedimentary soil under different loading directions.

[0072] 4. Shear test and dynamic response monitoring

[0073] While applying the load, use corresponding sensors (such as strain gauges, displacement gauges, etc.) to monitor the deformation of the test piece and record its dynamic response. At this time, the shear strain, pore water pressure, and deformation degree of the test piece will be recorded in real - time.

[0074] Collect the outflow volume of the liquid water of the test piece during the loading process through the drainage system (upper drainage hole 33 and lower drainage hole 26) in the device. This data will be used to evaluate the water discharge of the soil under dynamic loads.

[0075] 5. End of shear test and data recording

[0076] When the shear deformation of the test piece reaches the predetermined maximum limit, or when the liquid water discharge reaches the set standard, stop the loading and complete the test.

[0077] Record all key data, including load changes, stress - strain curves, pore water pressure changes, liquid water discharge volume, and the final deformation of the test piece.

[0078] Post - test treatment: After the test, remove the load and observe the recovery of the specimen and any permanent deformation. If necessary, subsequent physical property analyses can be carried out, such as soil particle composition, void ratio, liquid limit, and plastic limit. All data obtained during the test will be used to analyze the dynamic characteristics of deep - sea sedimentary soil under simulated deep - sea environments, including properties such as shear strength, compressibility, and liquid water discharge, providing a theoretical basis for soil mechanics research in deep - sea engineering.

[0079] Result analysis and report: Based on the stress - strain data, deformation data, and liquid water outflow obtained during the test, analyze the mechanical behavior of the soil, such as yield strength, shear modulus, and pore water pressure changes. Complete a test report that should include the physical properties of the specimen, test conditions, detailed records of the test process, analysis results, and conclusions to guide engineering design.

[0080] The above - mentioned is only the preferred implementation mode of this invention patent. It should be understood that this invention patent is not limited to the form disclosed herein, should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications, and environments, and can be changed within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. And any changes and alterations made by those skilled in the art without departing from the spirit and scope of this invention patent shall fall within the protection scope of the appended claims of this invention patent.

Claims

1. A soil shearing device for dynamic performance testing of deep-sea sedimentary soil, characterized in that: include: A reaction force frame (10), a support assembly (20), a clamping assembly (30) and a multi-directional loading assembly (40); The support assembly (20) is slidably arranged on the reaction force frame (10), a test piece is placed above the support assembly (20), and the pressing assembly (30) is in contact with the top surface of the test piece; The multi-directional loading component (40) comprises: a Z-direction loading member (43) in contact with the top surface of the pressing component (30), and an X-direction loading member (41) and a Y-direction loading member (42) in contact with the supporting component (20), respectively; the extension direction of the X-direction loading member (41) is perpendicular to the extension direction of the Y-direction loading member (42).

2. The soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to claim 1 is characterized in that: The support assembly (20) comprises: a pressure plate (21) slidably matched with the reaction frame (10), a base (22) arranged above the pressure plate (21), and a lower base (23) located above the base (22), the top surface of the lower base (23) is in contact with the specimen, and the outer wall of the base (22) is in contact with the X-direction loading member (41) and the Y-direction loading member (42), respectively.

3. The soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to claim 2, characterized in that: The bottom surface of the pressure plate (21) is connected to a plurality of rollers (24), and the reaction force frame (10) is provided with rolling grooves (11) that roll with the rollers (24).

4. The soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to claim 2, characterized in that: A lower O-ring (25) is also provided between the lower base (23) and the test piece, and the lower base (23) is provided with a lower drainage hole (26) connected to the test piece.

5. The soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to claim 1, characterized in that: The clamping assembly (30) comprises: an upper pressure head (31) located above the test piece and an upper O-ring (32) arranged between the test piece and the upper pressure head (31); the top surface of the upper pressure head (31) is in contact with the Z-direction loading member (43); and the upper pressure head (31) is provided with an upper drainage hole (33) connected to the test piece.

6. The soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to claim 2, characterized in that: A rigid restraining ring (60) is provided between the lower base (23) and the upper pressure head (31), and the rigid restraining ring (60) is sleeved on the outside of the test piece.

7. The soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to any one of claims 1 to 6, characterized in that: The top and bottom surfaces of the test piece are respectively provided with permeable stones (51).

8. The soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to claim 1, characterized in that: The X-direction loading member (41) comprises: an X-direction power cylinder (44) connected to the reaction force frame (10) and an X-direction connecting plate (45) arranged at the end of the X-direction power cylinder (44); The Y-direction loading member (42) comprises: a Y-direction power cylinder (46) connected to the reaction force frame (10) and a Y-direction connecting plate (47) arranged at the end of the Y-direction power cylinder (46), and the X-direction connecting plate (45) and the Y-direction connecting plate (47) are respectively connected to the supporting assembly (20); The Z-direction loading member (43) comprises: a Z-direction power cylinder (48) connected to the reaction force frame (10) and a Z-direction connecting plate (49) arranged at the end of the Z-direction power cylinder (48), and the Z-direction connecting plate (49) is connected to the clamping assembly (30).

9. The soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to claim 1, characterized in that: A temperature control system (70) is arranged between the reaction force frame (10) and the test piece, and the temperature control system (70) comprises: a thermal insulation cover (71) located outside the test piece, a refrigerator (72) arranged on the inner wall of the thermal insulation cover (71), and an exhaust valve (73) and a temperature sensor (74) respectively located on the top wall of the thermal insulation cover (71); the thermal insulation cover (71) is sealed with the base (22), so that a cold liquid cavity (75) is formed on the inner side of the thermal insulation cover (71); the Z-direction power cylinder (48) passes through the top wall of the thermal insulation cover (71), and the bottom of the thermal insulation cover (71) is connected to a liquid injection pipeline (76), which penetrates from the side wall of the base (22) and then passes out from the top surface of the base (22), thereby communicating with the cold liquid cavity (75).

10. A test method for a soil shearing device for dynamic performance testing of deep-sea sedimentary soil according to any one of claims 1 to 9, characterized in that: The steps include: S1. Specimen preparation and installation: Take an appropriate amount of deep-sea sedimentary soil samples and prepare specimens according to the size required by the test. The specimens are cylindrical in shape and have a flat upper surface to ensure uniform force during loading; The test piece is placed on the lower base (23) to ensure that the test piece is horizontal, and permeable stones (51) are placed on the upper and lower sides of the test piece respectively so that liquid water can be discharged smoothly during the test; Next, pressure is applied by the upper pressure head (31) to ensure that the test piece is in the correct position inside the test device; S2, temperature control: turn on the temperature control system (70), set the temperature required for the test, inject an appropriate amount of coolant into the cold liquid cavity (75), start the refrigerator (72), monitor and ensure that the temperature of the test piece is maintained within the set range through the temperature sensor (74); S3, loading process: applying an initial load to the specimen through a multi-directional loading assembly (40); Start the Z-direction power cylinder (48) to make the clamping assembly (30) act on the top of the test piece, and apply vertical pressure through the upper pressure head (31) to ensure that the test piece does not move or deform during the force application process; Gradually increase the loads in the X, Y and Z directions to simulate earthquakes or wave effects in different directions and examine the dynamic response of deep-sea sediments under different loading directions; S4. Shear test and dynamic response monitoring: Use sensors to monitor the shear strain, pore water pressure and deformation of the test piece, and record its dynamic response; The liquid water outflow of the specimen during the loading process is collected through the upper drainage hole (33) and the lower drainage hole (26) in the device, so as to evaluate the water discharge of the soil under the dynamic load; S5. End of shear test and data recording: When the shear deformation of the specimen reaches the predetermined maximum limit, or the liquid water discharge reaches the set standard, the loading is stopped and the test is completed; All critical data are recorded, including load changes, stress-strain curves, pore water pressure changes, liquid water discharge, and final deformation of the specimen.

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