Soil creep test system and test method

Abstract

The present invention discloses a soil creep test system and test method thereof, comprising an air pump, a triaxial measurement and control cabinet, an axial pressure regulating cabinet, a test reaction frame, a pressure chamber, a multi-channel controller, and a computer; the air pump is connected to the air inlet of the axial pressure regulating cabinet to provide axial pressure for the test; the air outlet of the axial pressure regulating cabinet is connected to the test reaction frame to apply axial pressure to the soil sample; the triaxial measurement and control cabinet is connected to the pressure device via a confining pressure pipeline and a back pressure pipeline; each channel of the multi-channel controller is respectively connected to the pore pressure interface and the deformation sensor, and the deformation displacement and pore pressure of the soil sample are collected in real time and transmitted to the computer for analysis. The soil creep test system of the present invention can perform triaxial creep compression tests on soil to study the creep properties of soil. At the same time, the supporting related test equipment can also perform K0 side pressure coefficient creep tests, pore pressure creep tests, uniaxial soil creep and Poisson's ratio tests, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of soil testing, and in particular to a soil creep testing system and a testing method thereof. Background Art

[0002] Infrastructure construction, such as buildings, transportation, water conservancy, and mining, involves numerous slope stability issues. Slopes can undergo various forms of deformation and failure during construction, such as landslides and collapses. Preventing these issues has long been a key research topic in this field, but this research presents numerous challenges, one of which is the inability to simulate soil creep in real time.

[0003] At present, soil creep tests are mainly divided into two major research topics: microscopic and macroscopic. The research on microscopic creep tests uses optical microscopes or electron scanning microscopes to observe the microscopic structure of the soil and use microscopic mechanisms to explain the creep characteristics of the soil. However, at present, only qualitative explanations can be achieved, and quantitative descriptions are still somewhat difficult.

[0004] Macro creep tests are divided into field creep tests and indoor creep tests. With the help of test instruments, through a series of test steps, the stress-strain-time relationship of the soil is studied to obtain the creep mechanical properties of the soil.

[0005] In-situ creep testing measures creep behavior of geotechnical materials, such as long-term foundation settlement and slope displacement. The results can better reflect the influence of structural and crack characteristics of geotechnical materials. Instruments used for in-situ creep testing include bearing plate instruments, large direct shear instruments, convergence instruments, station-hole multi-point displacement meters, inclinometers, and interferometers. In-situ creep testing provides firsthand data and is therefore of great guiding significance and value to specific projects. While in-situ creep testing offers simple instrumentation, it is also expensive, time-consuming, and susceptible to significant external interference. In particular, it lacks the ability to actively control the soil's stress state, stress path, and boundary conditions, which can affect the results.

[0006] Indoor creep testing involves testing the creep mechanical properties of soil specimens using a creep instrument within a laboratory. Indoor creep testing allows for controlled conditions such as stress, strain, and drainage, which are difficult to control in in-situ creep testing. Therefore, only indoor creep testing can investigate the complex properties of soils. Indoor testing has attracted considerable attention due to its advantages, such as strict control of stress, strain, and drainage, good repeatability, lack of external interference, and relatively low cost. The creep testing instruments used for indoor creep testing fall into two categories: those that directly apply shear forces, such as direct shear instruments and torsional shear instruments; and those that utilize tension or compression for creep testing, such as tensile creep instruments and compression creep instruments. Existing creep testing equipment suffers from a range of issues, including limited instrument functionality, overly simplistic test stress paths, manual tiered loading, and non-standardized test reading methods.

[0007] In many geotechnical engineering projects, soil cracks occur during loading, often due to tensile failure. For example, cracking is common in clay soils behind retaining walls and in clay slope landslides. When the slope soil deforms to a certain extent, shear or tensile failure occurs, resulting in cracks. These cracks are typically large and penetrate deep into the slope, posing a serious threat to soil slope projects. This is especially true for structural loess slopes, where relatively small displacements and sudden failures often lead to catastrophic consequences. Therefore, the long-term tensile and shear creep strengths of soils significantly impact the stability of geotechnical structures and slopes. In foundations, soil instability can occur under load due to shear failure under compression. For example, during the construction of high-rise buildings, foundations undergo compressive deformation, leading to shear failure and failure. Therefore, the long-term compressive and shear creep strengths of soils significantly impact the stability of soil foundations. The long-term movement of geological structures will cause deformation of the earth's crust, which will have a certain torsional shear deformation effect on the surface soil. In this case, it is of certain significance to study the long-term shear creep strength of the soil.

[0008] While studying the long-term creep strength of soils, attention should be paid to three other aspects: long-term tensile creep strength, long-term compressive creep strength, and long-term shear creep strength. While the shear and compressive creep strengths of soils are well-researched, there is no corresponding research on uniaxial tensile creep strength, triaxial tensile creep strength, uniaxial torsional shear creep strength, and triaxial torsional shear creep strength. Further research in these areas is highly valuable. Summary of the Invention

[0009] In order to solve the above problems, the present invention aims to provide a complete set of test systems and test methods that can be used to conduct triaxial creep tests, seepage creep tests and dissipative creep tests on soil, and to collect and analyze the test results.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0011] The soil creep test system includes a pressurizing device, a control device, a test main device and a data acquisition device, wherein the control device includes a three-axis measurement and control cabinet and an axial pressure regulating cabinet, and the data acquisition device includes a multi-channel controller and a computer;

[0012] The pressurizing device is connected to the air inlet of the axial pressure regulating cabinet to provide axial pressure for the test;

[0013] The test main device includes at least one test reaction frame, each of which is provided with a pressure chamber for placing a soil sample; each of which is provided with a pressure rod and a deformation sensor;

[0014] The air outlet of the axial pressure regulating cabinet is connected to each of the test reaction frames via an air path, so as to apply axial pressure to the soil sample in the corresponding pressure chamber;

[0015] Each of the pressure chambers is provided with a confining pressure interface, a back pressure interface, a pore pressure interface and a displacement applying unit; the displacement applying unit cooperates with the deformation sensor to measure the deformation displacement of the soil sample;

[0016] The three-axis measurement and control cabinet is connected to the surrounding pressure interface and the back pressure interface on each pressure chamber through the surrounding pressure pipeline and the back pressure pipeline;

[0017] A piston rod is provided on the top of the pressure chamber, and the pressure rod is located directly above the piston rod;

[0018] The multi-channel controller includes multiple displacement channels and pore pressure channels, each of the displacement channels is connected to a deformation sensor on its corresponding test reaction frame, and each of the pore pressure channels is connected to a pore pressure interface on its corresponding pressure chamber, so as to collect the deformation displacement and pore pressure of the soil sample in real time;

[0019] The multi-channel controller is connected to the computer via a wire to achieve data transmission function.

[0020] Furthermore, the test reaction frame includes a reaction frame base, a bracket and a crossbeam, the crossbeam is sleeved on the bracket and can be adjusted up and down, a pressure rod and a deformation sensor are provided on the crossbeam, the deformation sensor can contact with a displacement applying unit, and the displacement applying unit pre-compresses a deformation value for the deformation sensor; a ball head is provided at the bottom of the pressure rod; and a fine adjuster is also provided on the pressure rod;

[0021] A lifting plate is provided on the upper surface of the reaction frame base, and an air film for lifting the lifting plate is provided in the reaction frame base, and the air film is communicated with the air path.

[0022] Furthermore, the pressure chamber includes a pressure chamber base and an upper cover, the pressure chamber base and the upper cover form a closed space, and the pressure chamber base and the upper cover are detachably connected;

[0023] The bottom of the pressure chamber base is provided with a concave platform matching the lifting plate, and the concave platform cooperates with the lifting plate to enable the pressure chamber to be detachably connected to the test reaction frame;

[0024] A soil sample placement platform is provided at the center of the upper surface of the pressure chamber base; a piston rod is provided at the top of the upper cover, the piston rod extends into the upper cover, and the lower end surface of the piston rod has the same size as the cross-section of the soil sample; the center of the piston rod is located directly below the ball head;

[0025] An axial pressure sensor is provided on the piston rod, and the axial pressure sensor is located in the upper cover;

[0026] A pressure plate bracket is provided on the top of the upper cover, and a displacement applying unit is rotatably connected to the pressure plate bracket;

[0027] The pore pressure interface is located on one side of the pressure chamber base, a pore pressure sensor is provided at the pore pressure interface, and the pore pressure channel is connected to the pore pressure sensor;

[0028] The upper cover is also provided with a drainage port.

[0029] Furthermore, the three-axis measurement and control cabinet includes a water storage tank, a back-pressure volume variable tube, a volume variable tube, a pore volume variable tube and a measurement and control part;

[0030] The measurement and control part includes measurement and control of the confining pressure regulating pipeline, measurement and control of the back pressure regulating pipeline and measurement and control of the pressure chamber drainage pipeline; the measurement and control part includes measurement and control of the confining pressure regulating pipeline, measurement and control of the back pressure regulating pipeline and measurement and control of the pressure chamber drainage pipeline, which are all connected to the water storage tank and the pressure chamber;

[0031] The back pressure volume variable tube, the volume variable tube and the pore volume variable tube are all connected to the pressure chamber.

[0032] Furthermore, the pressurizing device is an air pump.

[0033] Furthermore, the axial pressure regulating cabinet is provided with a plurality of axial pressure regulating valves and axial pressure pressure gauges, each of the axial pressure regulating valves corresponds to an axial pressure pressure gauge; and each of the axial pressure regulating valves is connected to its corresponding test reaction frame.

[0034] Furthermore, the test method of the soil creep test system is characterized by comprising the following steps:

[0035] S1. Instrument connection: Connect the three-axis measurement and control instrument, axial pressure regulating cabinet, multi-channel controller, computer, test reaction frame and pressure chamber;

[0036] S2. Pressure and electrical test: Check the tightness of each pipeline, valve and gas circuit; check the communication between the computer software and the test host;

[0037] S3. Installing soil sample: installing the soil sample in the pressure chamber;

[0038] S4: Place the pressure chamber with the soil sample installed on the test reaction frame and adjust the height of the test reaction frame; make the pressure rod contact the piston rod, and the piston rod contact the soil sample, but without any force; install the deformation sensor and check the displacement data on the computer interface to ensure that there is enough displacement range in the test;

[0039] S5: Start the three-axis measurement and control cabinet and the axial pressure regulating cabinet to pressurize and stabilize the soil sample;

[0040] S6: inputting corresponding relevant parameters into the computer, starting the test, and recording and saving the data and curve graphs during the test; the test is a triaxial creep compression test, a permeation creep test, or a pore pressure dissipation test;

[0041] S7: After the test is completed, release the pressure, remove the soil samples, calculate and analyze the relevant data, and organize the results.

[0042] Furthermore, the specific operations of step S3 include:

[0043] S31: Place the latex film in the film-bearing cylinder, turn over both ends and put them outside the cylinder. The latex film must be flat and not wrinkled, and the upper and lower widths must be equal and flush.

[0044] S32: Insert a rubber tube onto the air nozzle of the membrane tube, connect an ear cleaning bulb to the end of the rubber tube to suck out the air between the latex membrane and the tube wall, so that the latex membrane is tightly attached to the membrane tube wall;

[0045] S33: Put the membrane tube with latex film on the pre-prepared soil sample, first turn over the lower latex film to tighten it around the soil sample placement table, and then seal it with a rubber band; then turn over the upper latex film, loosen the ear cleaning bulb, and remove the membrane tube;

[0046] S34: Pull down the piston rod to contact the top surface of the soil sample and seal it with a rubber band;

[0047] S35: Install the upper cover on the pressure chamber base. Note that the sealing ring of the pressure chamber base must be in the sealing groove. At the same time, pay attention to the sealing of the upper cover, otherwise it will cause leakage.

[0048] The beneficial effects of the present invention are as follows: compared with the prior art, the improvement of the present invention is that:

[0049] 1. The soil creep test system of the present invention can simulate the triaxial creep compression of soil under different confining pressures and different stress ratios, and quickly obtain the soil porosity pressure and deformation under different confining pressures and different stress ratios;

[0050] 2. The soil creep test system of the present invention can test a single soil sample or multiple soil samples at the same time;

[0051] 3. In the soil creep test system of the present invention, the axial pressure sensor is located in the pressure chamber, and can collect the actual axial pressure exerted on the soil sample in real time. Moreover, the pressure rod and the soil sample have the same cross-section. Since the axial pressure will be affected when the confining pressure is applied, the axial pressure collected by the axial pressure sensor when it is located outside the pressure chamber is avoided. Due to the influence of the confining pressure and the wear of the pressure rod, the deviation between the actual axial pressure exerted on the soil sample is avoided.

[0052] 4. The soil creep test system of the present invention can also perform K0 side pressure coefficient creep test, pore pressure creep test, uniaxial soil creep and Poisson's ratio test, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a connection diagram of the soil creep test system of the present invention.

[0054] Figure 2 This is a schematic diagram of the piping of the three-axis measurement and control cabinet of the soil creep test system of the present invention.

[0055] Figure 3 It is a schematic diagram of the pressure chamber structure of the soil creep test system of the present invention.

[0056] Figure 4 This is a schematic diagram of the test reaction frame structure of the soil creep test system of the present invention.

[0057] Figure 5 This is a front view of the control panel of the three-axis measurement and control cabinet of the present invention;

[0058] Figure 6 This is a back view of the control panel of the three-axis measurement and control cabinet of the present invention;

[0059] Figure 7This is a screenshot of the interface displayed on the LCD screen when the three-axis measurement and control cabinet of the present invention is turned on;

[0060] Figure 8 This is a screenshot of the interface displayed on the LCD screen after pressing the "Set" button on the control panel of the three-axis measurement and control cabinet of the present invention;

[0061] Figure 9 The three-axis measurement and control cabinet of the present invention is Figure 8 In the interface, press " key" or " key" to select "Time setting", press "OK key", and the interface screenshot will be displayed on the LCD screen;

[0062] Figure 10 The three-axis measurement and control cabinet of the present invention is Figure 8 In the interface, press " key" or " key" to select "Coefficient Calibration", and press "OK key", the interface screenshot is displayed on the LCD screen;

[0063] Figure 11 This is a screenshot of the interface displayed on the LCD screen after pressing the "calibration key" of the three-axis measurement and control cabinet of the present invention;

[0064] Figure 12 This is a screenshot of the interface displayed on the LCD screen after pressing the "test button" of the three-axis measurement and control cabinet of the present invention;

[0065] Figure 13 This is a screenshot of the interface displayed on the LCD screen after pressing the "Set key" corresponding to the surrounding pressure or counter pressure column of the three-axis measurement and control cabinet of the present invention.

[0066] Among them: 0-soil sample, 1-three-axis measurement and control cabinet, 101-water storage barrel, 102-confining pressure injection valve, 103-confining pressure valve, 104-pressure chamber drain valve, 105-back pressure injection valve, 106-back pressure valve, 107-back pressure drain valve, 108-pressure chamber valve, 109-volume change measurement valve, 110-pressure chamber injection valve, 111-back pressure volume change tube, 112-volume change tube, 113-pore measurement tube, 114-water pump, 115-confining pressure regulating valve, 116-confining pressure sensor, 117-back pressure regulating valve, 118-back pressure sensor, 119-confining pressure pressure gauge, 120-back pressure pressure gauge, 121-confining pressure pipeline, 122-back pressure pipeline, 123-pore pressure valve, 2-test reaction frame, 201-reaction frame base, 2 02-bracket, 203-crossbeam, 204-pressure rod, 205-deformation sensor, 206-fixing nut, 207-lifting plate, 208-ball head, 209-fine-tuner; 3-axial pressure regulating cabinet, 301-axial pressure regulating valve, 302-axial pressure pressure gauge, 303-air circuit, 4-multi-channel controller, 401-displacement channel, 402-pore pressure channel, 5-computer, 6-pressure chamber, 601-pressure chamber base, 602-upper cover, 603-piston rod, 604-soil sample placement table, 605-confining pressure interface, 606-back pressure interface, 607-pore pressure interface, 608-displacement application unit, 609-pressure plate bracket, 610-drainage port, 611-axial pressure sensor, 612-pore pressure sensor, 7-air pump. DETAILED DESCRIPTION

[0067] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments. Example 1

[0068] Refer to the attached Figure 1-4 The soil creep test system shown includes a pressurizing device, a control device, a test main body device and a data acquisition device.

[0069] Specifically, the pressurizing device is an air pump 7, the control device includes a three-axis measurement and control cabinet 1 and an axial pressure regulating cabinet 3; the data acquisition device includes a multi-channel controller 4 and a computer 5, and the test main device includes a test reaction frame 2 and a pressure chamber 6. The multi-channel controller 4 and the computer 5 are connected by a wire. In this embodiment, there are three test reaction frames 2 and three pressure chambers 6. In actual use, only one or two test reaction frames 2 and pressure chambers 6 can be used, and the number of test reaction frames 2 and pressure chambers 6 must be consistent.

[0070] Specifically, the air pump 7 is connected to the air inlet of the axial pressure regulating cabinet 3; the axial pressure regulating cabinet 3 performs flow diversion processing on the airflow to provide axial pressure;

[0071] The axial pressure regulating cabinet 3 is provided with three axial pressure regulating valves 301 and an axial pressure pressure gauge 302, and each axial pressure regulating valve 301 corresponds to an axial pressure pressure gauge 302; the air outlet of the axial pressure regulating cabinet 3 is connected to the three test reaction frames 2 through an air circuit 303, and each air circuit 303 corresponds to an axial pressure regulating valve 301 and an axial pressure pressure gauge 302.

[0072] Furthermore, the test reaction frame 2 includes a reaction frame base 201, a bracket 202 and a beam 203. The reaction frame base 201 is provided with two slots, and each of the slots is connected to a bracket 202 by a thread. The outer surface of the bracket 202 is provided with a thread, and the bottom of the bracket 202 is fixed to the reaction frame base 201 by a nut; a beam 203 is provided between the two brackets 202, and the beam 203 is provided with openings at positions corresponding to the brackets 202, and the beam 203 is sleeved on the outer side of the bracket 202 through the openings; each bracket 202 is provided with two fixing nuts 206, and the two fixing nuts 206 are respectively located above and below the beam 203. The threads on the outer surface of the bracket 202 cooperate with the fixing nuts 206 to fix the beam 203 to any height on the bracket 202, and the height of the beam 203 can be adjusted by adjusting the fixing nuts 206.

[0073] Furthermore, a vertical pressure rod 204 is provided at the middle position of the crossbeam 203. The height of the pressure rod 204 changes with the change of the height of the crossbeam 203. A fine-tuner 209 is provided on the pressure rod 204 for fine-tuning the height of the pressure rod 204. A ball head 208 is provided at the bottom of the pressure rod 204; a deformation sensor 205 is also provided on the crossbeam 203, and the deformation sensor 205 is located on one side of the pressure rod 204.

[0074] Furthermore, a lifting plate 207 is provided on the upper surface of the reaction frame base 201, and a pressurized chamber is provided in the reaction frame base 201. An air film is provided in the pressurized chamber to lift the lifting plate 207, and the air film is connected to its corresponding air path 303; the air flow in the air path 303 flows into the air film, changes the size of the air film, and lifts the lifting plate 207.

[0075] Furthermore, each of the test reaction frames 2 is provided with a pressure chamber 6 for placing a soil sample 0. The pressure chamber 6 includes a pressure chamber base 601 and an upper cover 602. The bottom of the upper cover 602 is a flange. The pressure chamber base 601 is provided with three threaded slots. The upper cover 602 is detachably connected to the pressure chamber base 601 by cap nuts and T-bolts. The bottom of the upper cover 602 is also provided with a sealing groove. The pressure chamber base 601 is correspondingly provided with a sealing ring. The model of the sealing ring is φ95×3.10. When installing the pressure chamber base 601 and the upper cover 602, it is necessary to ensure that the φ95×3.10 sealing ring on the base must be in the sealing groove, otherwise it will cause leakage and damage the O-ring. At the same time, care should be taken to avoid scratching, roughening, or smoothing the bottom surface of the upper cover to ensure that the sealing surface is flat, otherwise it will cause leakage. When the upper cover 602 and the pressure chamber base 601 are installed together, a closed space is formed inside the upper cover 602.

[0076] The bottom of the pressure chamber base 601 is provided with a recessed platform that matches the lifting plate 207. The recessed platform of the pressure chamber base 601 is placed on the lifting plate 207 at the top of the reaction frame 201, and the pressure chamber 6 is fixed on the test reaction frame 2. The diameter of the pressure chamber 6 is smaller than the distance between the two brackets 202.

[0077] A soil sample placement platform 604 is provided at the center of the upper surface of the pressure chamber base 601; the soil sample placement platform 604 is used to place the test soil sample 0. A piston rod 603 is provided at the top of the upper cover 602. The piston rod 603 extends into the upper cover 602, and the bottom of the piston rod 603 is higher than the soil sample placement platform 604. The bottom of the piston rod 603 is located directly above the soil sample placement platform 604, and the top of the piston rod 603 passes through the upper cover 602. The center of the piston rod 603 is located directly below the ball head 208 at the bottom of the pressure rod 204. The lower end surface of the piston rod 603 is the same size as the cross-section of the soil sample 0. When installing the pressure chamber base 601 and the upper cover 602, the three M10 cap nuts must be evenly tightened to ensure the verticality of the piston rod 603.

[0078] Furthermore, a sealing structure is provided at the place where the piston rod 603 contacts the upper cover 602. There are two types of seals. One is to seal at the gap and use 7501 silicone grease for sealing and lubrication; the other is to use an "O" type oil-resistant rubber sealing ring to seal and stop water. This method is used for sealing when the piston parts are worn out over a long period of time, resulting in increased gap and leakage.

[0079] Furthermore, an axial pressure sensor 611 is provided on the piston rod 603 . The axial pressure sensor 611 is located in the upper cover 602 . The axial pressure sensor 611 collects the axial pressure magnitude of the soil sample 0 in real time.

[0080] Furthermore, a pressure plate bracket 609 is provided on the top surface of the upper cover 602, and a displacement applying unit 608 is rotatably sleeved on the pressure plate bracket 609 near the top; the displacement applying unit 608 is located below the deformation sensor 205 on the test reaction frame 2, and before the test, the deformation sensor 205 can be in contact with the displacement applying unit 608, and the displacement applying unit 608 pre-presses a deformation value for the deformation sensor 205; during the test, the soil sample 0 undergoes deformation and displacement under the action of confining pressure and axial pressure, and the deformation is applied to the deformation sensor 205 through the displacement applying unit 608, and the deformation sensor 205 collects the displacement deformation of the soil sample 0, and the deformation sensor 205 is connected to the multi-channel controller 4 through the displacement channel 401, and transmits the real-time displacement deformation to the multi-channel controller 4.

[0081] Furthermore, a drainage vent 610 is provided on the upper cover 602 .

[0082] Furthermore, a confining pressure interface 605 and a back pressure interface 606 are provided at the front of the pressure chamber 6, and a pore pressure interface 607 is provided on one side of the pressure chamber 6. A pore pressure sensor 612 is provided at the pore pressure interface 607. The pore pressure sensor 612 is connected to the multi-channel controller 4 through the pore pressure channel 402 to transmit the pore pressure value to the multi-channel controller 4.

[0083] Furthermore, the multi-channel controller 4 is connected to the computer 5 via a USB data cable. The multi-channel controller 4 transmits the displacement deformation collected by the deformation sensor 205 and the pore pressure value collected by the pore pressure sensor 612 to the computer 5 via the USB data cable. The computer 5 records, saves, analyzes and plots the received data.

[0084] Furthermore, the three-axis measurement and control cabinet 1 includes a water storage tank 101, a back-pressure volume change tube 111, a volume change tube 112, a pore volume tube 113 and a measurement and control part; the three-axis measurement and control cabinet 1 is connected to the surrounding pressure interface 605 and the back-pressure interface 606 on each of the pressure chambers 6 through the surrounding pressure pipeline 121 and the back-pressure pipeline 122; the back-pressure volume change tube 111 is used to measure the volume change of the sample when back pressure is applied, the volume change tube 112 is used to measure the volume change of the sample when no back pressure is applied, and the pore volume tube 113 is used to measure the volume change and keep the pore pressure measurement system full of water to prevent air from infiltrating the system.

[0085] Furthermore, the measurement and control part includes measurement and control of the confining pressure regulating pipeline, measurement and control of the back pressure regulating pipeline and measurement and control of the pressure chamber drainage pipeline;

[0086] The confining pressure regulation pipeline monitoring and control system includes a confining pressure injection valve 102, a confining pressure valve 103, and a confining pressure regulating valve 115. The confining pressure regulation pipeline is equipped with a confining pressure sensor 116 and a confining pressure gauge 119. The confining pressure regulating pipe is equipped with a confining pressure regulating cylinder, which is equipped with the confining pressure injection valve 102 and the confining pressure valve 103. The confining pressure regulating cylinder consists of a pressure regulating cylinder, a piston, a 70TDY permanent magnet low-speed synchronous motor, a pair of worm gears, and a screw gear. The confining pressure regulating cylinder is controlled by a measurement and control instrument. Sensor feedback controls the synchronous motor's rotation, advancing or retracting the piston to maintain ambient pressure on the soil sample. By loosening the screw, the confining pressure injection valve 102 and the confining pressure valve 103 can be manually adjusted to fill the pressure regulating cylinder with water, drain or exhaust, and roughly adjust the ambient pressure. The confining pressure value can be directly read on the pressure gauge or the digital display window on the measurement and control instrument. When the piston of the pressure regulating cylinder moves to the front end, when the handwheel contacts the limit switch, the power supply is automatically cut off to protect the system. The confining pressure gauge 119 is a 0.4-level 1 MPa precision pressure gauge.

[0087] The back-pressure regulation pipeline measurement and control system includes a back-pressure water injection valve 105, a back-pressure valve 106, and a back-pressure regulating valve 117. The back-pressure regulation pipeline is equipped with a back-pressure sensor 118 and a back-pressure pressure gauge 120. The back-pressure regulating pipeline is equipped with a back-pressure regulating cylinder, which is equipped with the back-pressure water injection valve 105 and the back-pressure valve 106. The structure of the back-pressure regulating cylinder is the same as that of the confining pressure regulating cylinder described above. The back-pressure regulating cylinder is used to apply back pressure to the soil sample. The back-pressure regulating pressure gauge 120 is a 0.4-level 2.5 MPa precision pressure gauge.

[0088] The pressure chamber drainage pipeline measurement and control includes a pressure chamber drainage valve 104, a back-pressure drainage valve 107, a pressure chamber valve 108 and a pressure chamber water injection valve 110; the pressure chamber valve 108 is a three-way valve.

[0089] The measurement and control part also includes a water pump 114 for pumping water and a volume change measurement valve 109 for opening and closing during volume change measurement.

[0090] Furthermore, the three-axis measurement and control cabinet 1 is also provided with a control panel, which uses a liquid crystal full-Chinese character menu display and operation, can accurately measure the surrounding pressure, back pressure, and hole pressure, and can precisely control the surrounding pressure and back pressure.

[0091] The front view of the control panel is shown in the attached Figure 5 As mentioned above, the back side is as attached Figure 6 As shown, a liquid crystal screen is provided on the control panel.

[0092] Among them, power supply: instrument power switch, when the red light is on, the power is on;

[0093] Power socket: 220V AC power socket, connected to the power cord, with a fuse slot at the bottom, and a replaceable fuse;

[0094] Pore pressure: Pore pressure sensor socket;

[0095] Confining pressure: confining pressure sensor socket;

[0096] Back pressure: back pressure sensor socket;

[0097] Confining pressure control: confining pressure control motor socket;

[0098] Back pressure control: Back pressure control motor socket;

[0099] The system uses a liquid crystal display with a full Chinese menu and is equipped with a small number of function keys to achieve various complex functions and controls in the test. It is simple to operate and easy to use.

[0100] The system control menus are located at the bottom of the LCD screen, corresponding to the six function keys (F1, F2, F3, F4, F5, and F6). Pressing the key directly below the menu will perform the function described in the menu. Hereinafter, "pressing the key corresponding to a menu" will be referred to as "pressing the menu key." For example, the "Settings" menu corresponds to the F2 key, so pressing the "Settings key" is equivalent to pressing the F2 key.

[0101] Turn on the instrument and the LCD screen will display Figure 7 Press the "Settings" button, and the LCD screen will display the following interface: Figure 8 The interface shown. Press the "Back" key to return to Figure 7 The interface shown is shown; the " key" and " key" are used to select the "coefficient calibration" and "time setting" menus, and the selected ones are displayed in reverse color; press the "OK key" to implement the function of the selected menu.

[0102] exist Figure 8 In the interface shown, press " key" or " key" to select "Time Setting", and press "OK" to enter the Figure 9 In the interface shown, set the time.

[0103] Press the "Back" button to return to the previous interface (i.e. Figure 8 ).

[0104] Specific method of time setting:

[0105] First press the "←→" selection key to select the part to be modified (cycle through year, month, day, hour, minute, and second), then use the "plus and minus keys" to modify the corresponding value. After the time is set, press the "start key" to start normal timing.

[0106] The soil creep test system in the present invention uses pressure units of KPa and adopts 20-point multi-point calibration to basically eliminate the nonlinear error of the sensor. Figure 8In the interface shown, press " key" or " key" to select "Coefficient Calibration", and press "OK" to enter the following interface: Figure 10 In the interface shown, perform coefficient calibration.

[0107] Press the "Back" button to return to the previous interface (i.e. Figure 8 ).

[0108] The following are the descriptions of each item on this interface:

[0109] Channel: Displays the current channel. As shown in the figure, "01 Confining Pressure" indicates that the current display is the first channel, which is used for the confining pressure sensor. The "Select Key" cycles through channels. Each press increments the channel number, and the cycle repeats.

[0110] Range: Displays the range of the channel sensor. In the figure, "2000" indicates that the range of the pressure sensor is 2000 kPa. This can be set using the "Range Key".

[0111] Point: Displays the point number currently being recorded during the calibration process and the pressure (or other) value at that point.

[0112] Calibration points: Displays the number of calibration points, usually 20.

[0113] Current value: Displays the digital value after the current analog output of the sensor is converted. The display will be refreshed in real time and change with the changes in the measured value of the channel.

[0114] Gain: Displays the sensor signal amplification factor, which can be set using the "Gain Key." This provides an expandable platform for system upgrades and adaptability to different sensor types.

[0115] The specific method of coefficient calibration is: enter Figure 10 After the interface is displayed,

[0116] 1. Use the "Select key" to select the channel to be calibrated.

[0117] 2. Press the "Gain Key" to set the appropriate gain for the selected channel sensor.

[0118] Each time you press the "Gain Key", the gain increases by one level, and the display cycles from 1 to 128. The displayed value is the current set value.

[0119] (Note: This function is only available on models with gain control)

[0120] 3. Press the "Range Key" to set the range of the selected channel sensor.

[0121] After pressing the "Range Key," the cursor will flash in the range field. Use the "←→" keys to select the value to be modified, and then use the "plus and minus keys" to modify the corresponding value. Once the input is correct, press the "OK Key" to complete the range setting.

[0122] 4. Press the "calibration key" to start calibration.

[0123] After pressing the "calibration key", the LCD screen will show Figure 11 As shown, the "Point" column displays 0.0000, the "Calibration Point" column displays 20, and the menu changes. Now, reduce the pressure (or other measured value) of the pressure sensor (or other device) to 0 and press the "Record" button. The "Point" column on the screen now displays "Point 1." The original 0.0000 in this column becomes the next value to be calibrated. Add the pressure (or other measured value) to the displayed value and press "Record" again. After calibrating all 20 points, the "Record" button changes to the "Save" button. Press the "Save" button to save the calibration values. During the test, the system will use this calibration as a reference to calculate the measured values for that channel.

[0124] Regarding the use of the "Abort" button: To mitigate the effects of sensor nonlinearity on measurement, the system employs a 20-point multi-point calibration. These 20-point calibration values are calculated by dividing the range into 20 equal parts, increasing by one level at a time. For example, if the range is 2000, the starting point is 0, the first point is 100, the second point is 200, the third point is 300, and so on. The standard measuring instrument used for calibration may not have a standard value for the point we want to calibrate. For example, if the measuring instrument cannot measure the point 300, pressing the "Abort" button will abandon the calibration of that point and continue calibrating other points without affecting the calibration process or sensor measurement. It can also be considered that the fixed 20-point calibration can actually be converted to calibration with any number of points. For less demanding applications, calibrating the 0 point and any other point can complete the calibration and achieve measurement.

[0125] Regarding the "Load" and "Unload" buttons: When calibrating ambient backpressure, you can add a standard pressure gauge to the ambient backpressure line. Pressing the "Load" and "Unload" buttons controls the pressure regulator to increase and decrease pressure, adjusting to the desired pressure value for calibration. The system provides this adjustment interface. However, for calibration of other sensors, other methods are required to adjust the measured value and then record the calibration.

[0126] Note: The range, gain, and standard values for each point will be saved only after correctly completing steps 1, 2, 3, and 4. If an error occurs during calibration, press the "Cancel" button when the "Save" and "Cancel" buttons appear on the screen after 20 points have passed. Alternatively, press the "Return" button during calibration and then re-enter the calibration interface. This will not affect the previously saved range, gain, and standard values for each point.

[0127] When recalibrating the sensor, please do not change the range and gain. Try to use the factory default values unless the sensor is replaced.

[0128] Furthermore, when performing the confining pressure and back pressure control, turn on the controller power and the LCD screen will display the following Figure 7 Press the "Test" button, and the LCD screen will display the following interface: Figure 12 The interface shown.

[0129] The first line of the screen displays the date and time; the second line displays the current set values of the ambient and back pressures (the values that need to be stabilized); the third line displays the actual measured pressure values of the ambient and back pressures in real time.

[0130] There are corresponding "Set Key" and "Stable Pressure Key" under the Confining Pressure and Back Pressure columns.

[0131] Press the "Set" key corresponding to the surrounding pressure or counter pressure column, and the cursor will flash in the column. Figure 13 The interface is shown. Use the "←→" keys to select the value to be modified, then use the "plus and minus" keys to modify the corresponding value. Once the input is correct, press the "OK" key to complete the set value. After setting, press the "Stability" key, and the controller will automatically increase or decrease the pressure to the set value, continuously compensating to maintain the set value. During the voltage stabilization process, the "Stability" key becomes the "Stop" key. To stop the voltage stabilization, press the "Stop" key.

[0132] The surrounding pressure and back pressure can be set to different stabilization values respectively and stabilized at the same time without affecting each other.

[0133] Notice:

[0134] When using for the first time or after a long period of non-use, the pipeline must be vented by using the "fill" and "drain" functions, repeatedly filling and draining.

[0135] When not in use for a long time, drain all the water in the controller and start the water pump several times from time to time to prevent rust.

[0136] The water in the water bottle should be replaced regularly to keep it clean. It should not be turbid or contain dirt or impurities. Otherwise, the instrument may malfunction and shorten its service life.

[0137] If the sample contains corrosive media such as acid or alkali, after the test, all water in the controller should be drained immediately, and the water in the water storage bottle should be replaced. Use the "fill" and "drain" functions to clean the pipeline to avoid corrosion.

[0138] When filling or draining a container, please do not leave to avoid large amounts of water overflowing or prolonged operation of the pump.

[0139] Furthermore, the main technical parameters of the soil creep test system in the present invention are:

[0140] 1. Power supply: 220V 50Hz

[0141] 2. Power: 2kW

[0142] 3. Soil sample size: φ61.8×125mm

[0143] 4. Confining pressure: 0~2MPa, accuracy ±0.5%FS. Digital display, adjustable

[0144] 5. Back pressure: 0~1MPa, accuracy ±0.5%FS. Digital display, adjustable

[0145] 6. Pore pressure: 0~1MPa accuracy ±0.5%FS

[0146] 7. Deformation: 0~20mm±0.01mm

[0147] 8. Axial force: can be adjusted to a constant value, automatically loaded, 0~18KN (0~2.5MPa)

[0148] 9. Three samples can be made at the same time or separately

[0149] 10. Computer software for deformation collection, pore pressure collection, data storage, and graphics drawing

[0150] 11. Volume change measurement: 0~50ml Accuracy: 0.2ml

[0151] 12. Working environment:

[0152] There is a dedicated grounding wire indoors, and there is no strong electromagnetic interference

[0153] The performance is guaranteed under the working temperature of 10℃~40℃ and relative humidity less than 85%. It can be used under the conditions of 0℃~45℃ and relative humidity less than 85%.

[0154] Furthermore, the test method of the soil creep test system includes the following steps:

[0155] S1. Instrument connection: Assemble the pressurizing device, control device, test main device and data acquisition device;

[0156] Specifically, the air pump is connected to the air inlet of the axial pressure regulating cabinet, the air outlet of the axial pressure regulating cabinet is connected to the test reaction frame, the confining pressure pipeline and the back pressure pipeline of the three-axis measurement and control cabinet are connected to the confining pressure interface and the back pressure interface of the pressure chamber respectively, the deformation sensor is connected to the displacement channel of the multi-channel controller, the pore pressure sensor is connected to the pore pressure channel of the multi-channel controller, and the multi-channel controller is connected to the computer.

[0157] S2. Pressure and electrical test: Check the tightness of each pipeline, valve and gas circuit; check the communication between the computer software and the test host;

[0158] Specifically, the confining pressure pipeline and back pressure pipeline of the three-axis measurement and control cabinet are vented and pressure tested to ensure that there is no leakage in the confining pressure pipeline, back pressure pipeline, valves and pressure chambers; check the airtightness of the air circuit of the axial pressure regulating cabinet and the test reaction frame, and check the communication between the setting computer software and the test host.

[0159] Specifically, open the confining pressure water injection valve 102, unscrew the handwheel latch of the confining pressure regulating valve 115, turn the handwheel counterclockwise to pump water into the pressure regulating cylinder until it is full, close the confining pressure water injection valve 102, open the confining pressure valve 103, turn the handwheel of the confining pressure regulating valve 115 clockwise to discharge the water along the confining pressure pipeline 121 to the outlet of the confining pressure interface 605 of the pressure chamber 6, and repeat the above operation until water is discharged from the outlet of the confining pressure interface 605 of the pressure chamber 6, then, close the confining pressure water injection valve 102 and the confining pressure valve 103, and insert the latch on the confining pressure regulating valve 115. At this point, the exhaust operation of the confining pressure regulating cylinder is completed and it can be used normally.

[0160] Further, open the back-pressure water injection valve 105, unscrew the handwheel latch of the back-pressure regulating valve 117, unscrew the screw plug of the volume variable tube 112, turn the handwheel of the back-pressure regulating valve 117 counterclockwise, pump water into the back-pressure regulating cylinder until it is full, open the back-pressure valve 106 and the volume change measuring valve 109, close the back-pressure water injection valve 105, turn the handwheel of the back-pressure regulating valve 117 clockwise, repeat the above operation, fill the volume variable tube 112 with water first, and then pump water along the small glass tube in the volume variable tube 112 through the back-pressure regulating cylinder. The volume change measuring valve 109 injects water into the back pressure interface 606 of the pressure chamber 6. Water overflows from the outlet of the back pressure interface 606. Close the volume change measuring valve 109 and continue to turn the handwheel of the back pressure regulating valve 117 clockwise until the volume change tube 112 is filled with water. Screw on the screw plug on the volume change tube 112, close the pressure chamber drain valve 104 and the back pressure water injection valve 105, and insert the pin on the back pressure regulating valve 117. At this point, the exhaust operation of the back pressure regulating cylinder is completed and can be used normally.

[0161] Add water to the pore measuring tube 113, open the pore pressure valve 123, and close the pore pressure valve 123 when water overflows from the pressure chamber base 601. At this point, the drainage operation of the pore measurement system is completed and can be used normally.

[0162] S3. Installing soil sample: installing the soil sample in the pressure chamber;

[0163] Specifically, S31: Place the latex film in the film-bearing tube, turn over the two ends and put them outside the tube, pay attention that the latex film must be flat and not wrinkled, and the upper and lower turned-out widths are equal and flush, put a rubber tube on the air nozzle of the film-bearing tube, and then connect an ear cleaning bulb to the end of the rubber tube to suck out the air between the latex film and the tube wall, so that the latex film is tightly attached to the wall of the film-bearing tube;

[0164] S32: Insert a rubber tube onto the air nozzle of the membrane tube, connect an ear cleaning bulb to the end of the rubber tube to suck out the air between the latex membrane and the tube wall, so that the latex membrane is tightly attached to the membrane tube wall;

[0165] S33: Put the membrane tube with latex film on the pre-prepared soil sample, first turn over the lower latex film to tighten it around the soil sample placement table, and then seal it with a rubber band; then turn over the upper latex film, loosen the ear cleaning bulb, and remove the membrane tube;

[0166] S34: Pull down the piston rod to make contact with the top surface of the soil sample, and seal it with a rubber band. Be careful not to break the air nozzle during use.

[0167] S35: Install the upper cover on the pressure chamber base. Make sure the sealing ring of the pressure chamber base is sealed in the groove. At the same time, make sure the upper cover is sealed tightly, otherwise it will cause leakage. When loading the soil sample, place permeable stone and filter paper at the bottom and top of the soil sample in sequence. Place an impermeable board above and below the soil sample.

[0168] Furthermore, the specifications of the film-bearing cylinder are shown in Table 1.

[0169] Table 1 Specifications of film cylinder

[0170]

[0171] Furthermore, most of the soil samples used in triaxial tests are saturated soils. When in use, the soil samples are placed in a saturator for capillary saturation and vacuum saturation. It consists of an upper cover, a base, a permeable stone and a three-petal tube. The specifications of the saturator are shown in Table 2.

[0172] Table 2 Saturator specifications

[0173]

[0174] Specifically, place the cut sample in a three-lobed tube, put on a hoop, cut off the excess soil at the top and bottom, and place a piece of filter paper at each end. Place the soil sample tube on the permeable stone in the base, then place another permeable stone on the bucket, install the nylon cover, tighten the disc nut, and then place it in the saturation equipment for saturation.

[0175] After the sample is saturated, loosen the hoop and push the three petals in sequence along the axial direction by hand to remove the soil.

[0176] Each piece of the three-petal tube is numbered. When assembling, assemble them according to the numbers. Do not assemble them incorrectly or interchange them. Be careful not to damage the edges to avoid affecting the fit.

[0177] After use, wipe it clean, apply oil to the metal parts for protection, and wash away the remaining soil on the permeable stone.

[0178] The base and top cover are made of nylon. When tightening the rod, do not use excessive force to avoid damage.

[0179] S4: Place the pressure chamber with the soil sample installed on the test reaction frame and adjust the height of the test reaction frame;

[0180] Specifically, loosen the fixing nut on the bracket, adjust the height of the beam and then tighten the fixing nut, then adjust the fine-tuning device so that the pressure rod contacts the piston rod of the pressure chamber, and the piston rod contacts the top of the soil sample but is not subjected to force; adjust the displacement application unit to pre-press a deformation value for the deformation sensor, check the displacement data on the software interface on the computer, and ensure that there is enough displacement range in the test.

[0181] S5: Start the three-axis measurement and control cabinet and the axial pressure regulating cabinet to pressurize and stabilize the soil sample;

[0182] Specifically, start the three-axis measurement and control cabinet, open the drainage port 610 on the top of the pressure chamber 6, set the pressure chamber valve 108 to the "water filling" position, open the pressure chamber water filling valve 110, and turn on the water pump 114 to fill water into the pressure chamber 6. When the water in the pressure chamber 6 is almost full, close the pressure chamber valve 108 and the pressure chamber water filling valve 110, open the confining pressure water filling valve 102 and the confining pressure valve 103, so that the pressure chamber 6 is naturally filled with water until it is full, close the drainage port 610 on the top of the pressure chamber 6 (it can be closed with a screw plug), and close the confining pressure water filling valve 102.

[0183] When applying confining pressure to three soil samples at the same time, the three pressure chambers need to be connected in series and pressurized simultaneously.

[0184] S6: Input relevant parameters into the computer, start the test, and record and save the data and curve graphs during the test;

[0185] Specifically, a triaxial creep test is performed on soil sample 0, and confining pressure is applied around soil sample 0. At the same time, the air pump 7 is started. The airflow of the air pump 7 expands the air film in the reaction frame base 201, driving the lifting plate 207 to rise. The pressure rod 204 applies axial pressure to the soil sample 0, the deformation sensor 205 collects the deformation displacement of soil sample 0, and the pore pressure sensor 612 collects the void pressure, which is transmitted to the multi-channel controller 4 through the displacement channel 401 and the pore pressure channel 402, and then transmitted to the computer 5 through the USB connection.

[0186] S7: After the test is completed, release the pressure, remove the soil samples, calculate and analyze the relevant data, and organize the results. Example 2

[0187] The soil creep test system in this embodiment is exactly the same as that in Example 1. In the test method of the soil creep test system, in step S3, after the soil sample is loaded, no impermeable plates are placed above or below the soil sample. In step S6, a permeability creep test is performed on soil sample 0, and the remaining steps are the same.

[0188] Example 3:

[0189] The soil creep test system in this embodiment is exactly the same as that in Example 1. In the test method of the soil creep test system, in step S3, after the soil sample is loaded, no impermeable plates are placed above or below the soil sample. In step S6, a pore pressure dissipation test is performed on soil sample 0, and the remaining steps are the same.

[0190] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A soil creep test system, comprising a pressurizing device, a control device, a test main device, and a data acquisition device, is characterized by: The control device includes a three-axis measurement and control cabinet (1) and an axial pressure regulating cabinet (3); the data acquisition device includes a multi-channel controller (4) and a computer (5); The pressurizing device is connected to the air inlet of the axial pressure regulating cabinet (3) to provide axial pressure for the test; The test main body device comprises at least one test reaction frame (2), each of the test reaction frames (2) being provided with a pressure chamber (6) for placing a soil sample (0); each of the test reaction frames (2) being provided with a pressure rod (204) and a deformation sensor (205); The air outlet of the axial pressure regulating cabinet (3) is connected to each of the test reaction frames (2) via an air path (303), so as to apply axial pressure to the soil sample (0) in the corresponding pressure chamber (6); Each of the pressure chambers (6) is provided with a confining pressure interface (605), a back pressure interface (606), a pore pressure interface (607), and a displacement applying unit (608); the displacement applying unit (608) cooperates with the deformation sensor (205) to measure the deformation displacement of the soil sample (0); The three-axis measurement and control cabinet (1) is connected to the surrounding pressure interface (605) and the back pressure interface (606) on each pressure chamber (6) via a surrounding pressure pipeline (121) and a back pressure pipeline (122); A piston rod (603) is provided at the top of the pressure chamber (6), and the pressure rod (204) is located directly above the piston rod (603); The multi-channel controller (4) includes a plurality of displacement channels (401) and pore pressure channels (402), each of the displacement channels (401) is connected to a deformation sensor (205) on a corresponding test reaction frame (2), and each of the pore pressure channels (402) is connected to a pore pressure interface (607) on a corresponding pressure chamber (6), so as to collect the deformation displacement and pore pressure of the soil sample (0) in real time; The multi-channel controller (4) is connected to the computer (5) via a wire to realize a data transmission function; The three-axis measurement and control cabinet (1) comprises a water storage bucket (101), a back pressure volume change tube (111), a volume change tube (112), a pore volume tube (113), and a measurement and control part; The measurement and control part includes measurement and control of the confining pressure regulating pipeline, measurement and control of the back pressure regulating pipeline and measurement and control of the pressure chamber drainage pipeline; The back pressure volume change tube (111), the volume change tube (112) and the pore volume tube (113) are all connected to the pressure chamber (6); The confining pressure regulating pipeline measurement and control comprises a confining pressure regulating cylinder, on which a confining pressure water injection valve (102), a confining pressure valve (103) and a confining pressure regulating valve (115) are provided; the confining pressure regulating pipeline measurement and control is also provided with a confining pressure sensor (116) and a confining pressure gauge (119); The back pressure regulating pipeline measurement and control system includes a back pressure regulating cylinder, on which a back pressure water injection valve (105), a back pressure valve (106) and a back pressure regulating valve (117) are provided, and the back pressure regulating pipeline measurement and control system is provided with a back pressure sensor (118) and a back pressure pressure gauge (120); The pressure chamber drainage pipeline measurement and control includes a pressure chamber drainage valve (104), a back-pressure drainage valve (107), a pressure chamber valve (108), and a pressure chamber water injection valve (110); The measurement and control part also includes a water pump (114) for pumping water and a volume change measurement valve (109) for opening and closing during volume change measurement.

2. The soil creep testing system according to claim 1, characterized in that: The test reaction frame (2) includes a reaction frame base (201), a bracket (202) and a crossbeam (203), wherein the crossbeam (203) is sleeved on the bracket (202) and can be adjusted up and down, and a pressure rod (204) and a deformation sensor (205) are provided on the crossbeam (203), wherein the deformation sensor (205) can contact a displacement applying unit (608), and the displacement applying unit (608) pre-presses a deformation value for the deformation sensor (205); a ball head (208) is provided at the bottom of the pressure rod (204); and a fine adjuster (209) is also provided on the pressure rod (204); A lifting plate (207) is provided on the upper surface of the reaction frame base (201), and an air film for lifting the lifting plate (207) is provided inside the reaction frame base (201), and the air film is connected to the air path (303).

3. The soil creep testing system according to claim 2, characterized in that: The pressure chamber (6) comprises a pressure chamber base (601) and an upper cover (602), wherein the pressure chamber base (601) and the upper cover (602) form a closed space, and the pressure chamber base (601) and the upper cover (602) are detachably connected; The bottom of the pressure chamber base (601) is provided with a concave platform that matches the lifting plate (207), and the concave platform cooperates with the lifting plate (207) to enable the pressure chamber (6) to be detachably connected to the test reaction frame (2); A soil sample placement platform (604) is provided at the center of the upper surface of the pressure chamber base (601); a piston rod (603) is provided at the top of the upper cover (602), the piston rod (603) extends into the upper cover (602), and the lower end surface of the piston rod (603) is the same size as the cross-section of the soil sample (0); the center of the piston rod (603) is located directly below the ball head (208); An axial pressure sensor (611) is provided on the piston rod (603), and the axial pressure sensor (611) is located inside the upper cover (602); A pressure plate bracket (609) is provided on the top of the upper cover (602), and a displacement applying unit (608) is rotatably connected to the pressure plate bracket (609); The pore pressure interface (607) is located on one side of the pressure chamber base (601), a pore pressure sensor (612) is provided at the pore pressure interface (607), and the pore pressure channel (402) is connected to the pore pressure sensor (612); The upper cover (602) is also provided with a drainage vent (610).

4. The soil creep testing system according to claim 1, characterized in that: The pressurizing device is an air pump (7).

5. The soil creep testing system according to claim 1, characterized in that: The axial pressure regulating cabinet (3) is provided with a plurality of axial pressure regulating valves (301) and axial pressure gauges (302), each of the axial pressure regulating valves (301) corresponding to one axial pressure gauge (302); and each of the axial pressure regulating valves (301) is connected to its corresponding test reaction frame (2).

6. The test method of the soil creep test system according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Instrument connection: Connect the three-axis measurement and control instrument, axial pressure regulating cabinet, multi-channel controller, computer, test reaction frame and pressure chamber; S2. Pressure and electrical test: Check the tightness of each pipeline, valve and gas circuit; check the communication between the computer software and the test host; S3. Installing soil sample: installing the soil sample in the pressure chamber; S4: Place the pressure chamber with the soil sample installed on the test reaction frame and adjust the height of the test reaction frame; Make the pressure rod contact the piston rod, and the piston rod contact the soil sample, but without any force; install the deformation sensor, check the displacement data on the computer interface, and ensure that there is enough displacement range in the test; S5: Start the three-axis measurement and control cabinet and the axial pressure regulating cabinet to pressurize and stabilize the soil sample; S6: inputting corresponding relevant parameters into the computer, starting the test, and recording and saving the data and curve graphs during the test; the test is a triaxial creep test, a permeation creep test, or a pore pressure dissipation test; S7: After the test is completed, release the pressure, remove the soil samples, calculate and analyze the relevant data, and organize the results.

7. The test method of the soil creep test system according to claim 6, characterized in that: The specific operations of step S3 include: S31: Place the latex film in the film-bearing cylinder, turn over both ends and put them outside the cylinder. The latex film must be flat and not wrinkled, and the upper and lower widths must be equal and flush. S32: Insert a rubber tube onto the air nozzle of the membrane tube, connect an ear cleaning bulb to the end of the rubber tube to suck out the air between the latex membrane and the tube wall, so that the latex membrane is tightly attached to the membrane tube wall; S33: Put the membrane tube with latex film on the pre-prepared soil sample, first turn over the lower latex film to tighten it around the soil sample placement table, and then seal it with a rubber band; then turn over the upper latex film, loosen the ear cleaning bulb, and remove the membrane tube; S34: Pull down the piston rod to contact the top surface of the soil sample and seal it with a rubber band; S35: Install the upper cover on the pressure chamber base. Note that the sealing ring of the pressure chamber base must be in the sealing groove. At the same time, pay attention to the sealing of the upper cover, otherwise it will cause leakage.

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