Large-scale indoor simulation device and method for in-situ soil layers

Abstract

The present invention relates to the technical field of indoor soil testing equipment, and provides a large-scale indoor simulation device and method for in-situ soil layers. The simulation device comprises: a foundation base plate, a material barrel with a measuring hole connected to the foundation base plate via a cooperative loading jack, a flexible sleeve provided on the inner wall of the material barrel, and an upper cover plate with a variable diameter test hole provided at the open end of the material barrel; support columns are used to penetrate the upper cover plate and the foundation base plate, and are fixed with nuts; a force sensor is provided inside the cooperative loading jack, and a displacement sensor is provided outside the cooperative loading jack, and the cooperative loading jack, force sensor, and displacement sensor are all connected to a loading console. The present invention can simulate the density, stress, and other in-situ characteristics of the in-situ soil layer in indoor simulated field tests, and provides the necessary equipment and technical support for conducting calibration tests for indoor simulated field in-situ tests.

Description

Technical Field

[0001] The present invention relates to the technical field of indoor soil testing equipment, and in particular to a large-scale indoor simulation device and method for in-situ soil layers. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] At present, the static and dynamic properties of soil are mainly studied by conducting indoor tests on reshaped soil materials, and the corresponding characteristic parameters are determined. Indoor static and dynamic characteristic tests can simulate the rich stress conditions and other external control conditions of the soil, and obtain the characteristic parameters of various types of static and dynamic constitutive models of soil through systematic testing. However, it is difficult to reflect the in-situ structural characteristics of natural soil layers, and it is difficult to reliably determine the characteristic parameters of soil by relying solely on indoor tests. Field in-situ tests are carried out on actual soil layers, with little disturbance to the in-situ soil. They can more realistically reflect the in-situ structural effects and in-situ stress states of the soil, and at the same time solve the size effect problem caused by equipment size limitations in indoor tests. However, the test conditions of field in-situ tests are relatively simple and difficult to control. The test stress conditions are simple, making it difficult to conduct tests with different consolidation stress states and to verify the complex influence relationship of multiple factors such as in-situ density (relative density).

[0004] Simulating on-site in-situ conditions indoors, constructing a soil layer that can reflect the actual on-site conditions, and conducting on-site in-situ test calibration tests under controllable conditions are reasonable ways to solve the problems existing in the existing single indoor reshaped soil test and on-site in-situ test, integrate the advantages of both for comprehensive research and determine the static and dynamic characteristic parameters of the covering soil. Summary of the Invention

[0005] In order to solve the technical problems existing in the above-mentioned background technology, the present invention provides a large-scale indoor simulation device and method for in-situ soil layers. The present invention develops a large-scale indoor simulation device for in-situ soil layers and proposes corresponding test methods for conducting calibration tests of indoor simulated field in-situ tests. It can extend single, specific field test conditions to different in-situ conditions, and provides the necessary equipment and technical support for reliably determining the mechanical properties and parameters of the in-situ soil layer by combining field in-situ tests and indoor test results.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A first aspect of the present invention provides a large-scale indoor simulation device for in-situ soil layers.

[0008] A large-scale indoor simulation device for in-situ soil layers comprises: a foundation base plate, a material barrel with a measuring hole connected to the foundation base plate via a cooperative loading jack, a flexible sleeve provided on the inner wall of the material barrel, and an upper cover plate with a variable-diameter test hole provided at the open end of the material barrel; support columns passing through the upper cover plate and the foundation base plate and secured with nuts;

[0009] A force sensor is provided inside the cooperative loading jack, and a displacement sensor is provided outside the cooperative loading jack. The cooperative loading jack, the force sensor and the displacement sensor are all connected to the loading console.

[0010] Furthermore, a directional bearing is provided on the support column, and the directional bearing includes a bearing bracket and a bearing. The support column passes through the bearing bracket, and the directional bearing is fastened to the support column by the bearing bracket. The bearing is in vertical contact with the outer wall of the barrel.

[0011] Furthermore, a reducing hole with a hole bolt is provided in the upper cover plate, a reducing hole with a hole bolt is provided in the reducing hole with a hole bolt, and the centers of the reducing hole with a hole bolt, the center of the reducing hole with a hole bolt and the center of the barrel are coaxial.

[0012] Furthermore, the support columns are fixed to the upper cover plate by using positioning nuts, and the support columns are fixed to the base bottom plate by using fastening nuts.

[0013] Furthermore, a hole is also provided at a position corresponding to the opening of the flexible sleeve and the barrel.

[0014] Furthermore, a plurality of groups of measuring hole bolts are provided on the side wall of the barrel.

[0015] Furthermore, a lubricating material is applied between the flexible sleeve and the barrel.

[0016] A second aspect of the present invention provides a large-scale indoor simulation method for in-situ soil layers.

[0017] A large-scale indoor simulation method for an in-situ soil layer, applied to the large-scale indoor simulation device for an in-situ soil layer described in the first aspect, comprises:

[0018] Place a thin flexible sleeve with a lubricating material (such as vaseline, carbon powder, etc.) on the outer wall into the barrel and fit it tightly against the inner wall of the barrel; according to the position of the measuring hole of the barrel, make a hole at the corresponding position of the flexible sleeve;

[0019] The test soil material is loaded into the bucket with measuring holes in layers according to the preset relative density. After each layer is loaded, it is compacted using a compaction instrument to restore the density. After one round of compaction, it is measured and compared to see whether it has been compacted to the specified height. If not, the next round of compaction is carried out until the specified height is reached, completing the compaction of one layer of soil material. During this process, the corresponding measuring hole bolts are removed at the required locations according to the test needs and sensors are arranged.

[0020] Install the upper cover plate, start the coordinated loading jack through the loading console, and load the soil material to the preset stress state according to the signal of the force sensor to complete the loading;

[0021] Conduct indoor simulation tests for on-site in-situ testing.

[0022] Furthermore, the compaction process adopts manual compaction and electric compaction respectively according to the density requirements of the soil sample; when manual compaction or electric compaction is performed, the compaction process follows the basic principle of from outside to inside, first tamping along the inner wall of the barrel with the measuring hole, and then the compactor is moved inward and the next circle of compaction is performed along the inner diameter of the compacted track. During the compaction process, the two compaction tracks should partially overlap to ensure that the compaction range is fully covered.

[0023] Furthermore, before conducting the indoor simulation test, remove the bolts in the reducing holes or the bolts with holes in the reducing holes.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] In order to reliably determine the mechanical properties and parameters of the soil by combining the results of on-site in-situ tests with those of indoor tests, it is necessary to carry out calibration tests of indoor simulated on-site in-situ tests. The present invention has developed a large-scale indoor simulation device for in-situ soil layers and proposed a corresponding test method. Rigid side walls are used to limit the lateral deformation of the soil, and vertical loads are applied by jacks to simulate the in-situ stress state of the in-situ soil layer; the in-situ density of the in-situ soil layer is simulated by controlling the sample preparation method. At the same time, the device provides variable-diameter test holes and multiple measuring holes, which provide basic conditions for further carrying out indoor simulation tests of various on-site tests. The present invention can simulate the in-situ states of the density, stress, etc. of the in-situ soil layer in indoor simulated field tests, and provides the necessary equipment and technical support for carrying out calibration tests of indoor simulated on-site in-situ tests.

[0026] The present invention has a built-in flexible sleeve, which is in smooth contact with the inner wall of the barrel and deforms in complete coordination with the soil during the test, thereby reducing the friction between the soil and the barrel wall and keeping the stress state inside the soil consistent as much as possible. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 1 is a structural diagram of a large-scale indoor simulation device for in-situ soil layers shown in the present invention;

[0029] Figure 2 This is a detailed structural diagram of the upper cover plate with a variable diameter test hole shown in the present invention;

[0030] Figure 3 This is a detailed diagram of the basic base plate of the present invention;

[0031] Figure 4 1. It is a detailed structural diagram of a directional bearing according to the present invention;

[0032] Among them, 1. Fastening nut, 2. Upper cover plate, 3. Bolt with hole in reducing hole, 4. Bolt in reducing hole, 5. Support column, 6. Material barrel, 7. Collaborative loading jack, 8. Basic base plate, 9. Positioning nut, 10. Measuring hole bolt, 11. Directional bearing, 12. Force sensor, 13. Displacement sensor, 14. Loading console, 15. Flexible sleeve, 16. Bearing bracket, 17. Bearing. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0034] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0036] The in-situ structure of the in-situ soil layer mentioned in the background technology is very easy to be destroyed due to the sampling disturbance during the sampling process. The large-scale special sampling method on site is not suitable for general engineering due to its high cost. The results of the indoor remolding sample test are difficult to reflect the in-situ structural influence and the physical and mechanical properties of the soil. The test conditions of the on-site in-situ test are single and difficult to control, and the characteristic parameters of the static and dynamic constitutive model of the soil cannot be directly obtained. Therefore, it is necessary to carry out indoor calibration tests to simulate on-site in-situ tests, and to extend the single and specific on-site test conditions to different in-situ conditions, so as to provide the necessary conditions for reliably determining the mechanical properties and parameters of the in-situ soil layer by combining the results of on-site in-situ tests and indoor remolding sample tests. The existing indoor test devices are all special test equipment for specific tests. There is a lack of test devices and technologies that can restore the in-situ soil state and provide basic conditions for carrying out various on-site test simulation tests, which restricts the development of indoor simulation test research on on-site in-situ tests. In order to give full play to the respective advantages of indoor and outdoor tests, and to combine the results of field in-situ tests with indoor test results to reliably determine the mechanical properties and parameters of the in-situ soil layer, it is necessary to carry out calibration tests to simulate the in-situ field test, and to generalize the single, specific field test conditions to different in-situ conditions. It is necessary to develop a large-scale indoor simulation device and method for the in-situ soil layer that can restore the state of the field soil layer. The present invention is described in detail below through several embodiments:

[0037] Example 1

[0038] like Figure 1 As shown, this embodiment provides a large-scale indoor simulation device for in-situ soil layers, and the components in the figure are respectively a fastening nut 1, an upper cover plate 2 with a variable diameter test hole, a bolt with a hole in the variable diameter hole 3, a bolt in the variable diameter hole 4, a support column 5, a barrel with a measuring hole 6, a cooperative loading jack 7, a foundation base plate 8, a positioning nut 9, a bolt with a measuring hole 10, a directional bearing 11, a force sensor 12, a displacement sensor 13, a loading console 14 and a flexible sleeve 15.

[0039] The aperture of the test hole of the upper cover plate 2 is determined according to the test aperture requirements of the on-site in-situ test for the indoor simulation test to be carried out, and the material stiffness of the upper cover plate 2 should meet the deformation requirements during the loading process; the aperture of the measuring hole of the material barrel 6 is determined according to the installation size requirements of the sensor to be arranged, and the barrel diameter and height of the material barrel 6 are determined according to the maximum particle size of the soil material and meet the requirements of the on-site in-situ test for the indoor simulation test to be carried out; the material stiffness of the side wall of the material barrel 6 should be much greater than the stiffness of the soil to meet the lateral deformation requirements during the loading process, and steel can be used.

[0040] The present invention determines the size of the material bucket 6 according to the maximum particle size of the soil material, so that the central soil body is less affected by the side wall constraints during loading and testing, and the boundary effect can be ignored.

[0041] The side wall of the material barrel 6 of the present invention is a rigid boundary with a stiffness far greater than that of the soil, which can strictly control its own lateral deformation. The loading console controls the lifting and lowering of the collaborative loading jack, and the upper cover provides a reaction force to apply a vertical load to the soil sample, thereby restoring the stress state of the in-situ soil layer.

[0042] A thin flexible sleeve 15 is placed inside the barrel 6, tightly fitting the inner wall of the barrel 6. A lubricant (such as petroleum jelly or carbon powder) is applied to the outer wall of the sleeve 15 to reduce friction with the barrel 6. The inner wall of the sleeve 15 maintains rough contact with the soil material, and during the test, the sleeve 15 and the soil material deform in perfect harmony, without affecting the material's deformation characteristics. This method reduces friction between the soil material and the barrel wall, minimizing the stress on the material within the barrel.

[0043] The detailed structures of the upper cover plate 2 and the foundation bottom plate 8 of the large indoor simulation device of the in-situ soil layer are as follows: Figure 2 and Figure 3 As shown. Different on-site in-situ tests have different requirements for the test hole diameter. In order to meet the indoor simulation needs of various in-situ tests, this device is designed with variable diameter test holes in the upper cover plate, and multiple sets of replaceable variable diameter hole bolts 3 and corresponding variable diameter hole inner bolts 4 are used to meet the test requirements. For the test hole diameter required by different tests, the variable diameter hole bolts 3 and the corresponding variable diameter hole inner bolts 4 that match the hole diameter can be selected for installation before the test loading stage. During the test, the variable diameter hole inner bolts 4 can be removed separately or the variable diameter hole bolts 3 and the variable diameter hole inner bolts 4 can be removed together as needed, leaving a test hole of the required size for the test for in-situ testing. In addition to being able to meet the test hole opening requirements, this method minimizes the load unloading above the soil except for the test hole position, avoiding affecting the accuracy of subsequent test results.

[0044] The present invention utilizes replaceable reduced-diameter hole bolts 3 and reduced-diameter hole bolts 4 to meet various in-situ testing requirements for indoor simulation. The shape, size, and number of the reduced-diameter hole bolts 3, reduced-diameter hole bolts 4, and measurement hole bolts 10 can be modified to meet actual working conditions, such as by using multiple layers of hole bolts. This is not a limitation of the present invention. The present invention also allows for modifications to the geometry of the component ribs or the use of solid components.

[0045] The detailed structure of the directional bearing 11 of the large indoor simulation device of the in-situ soil layer is as follows Figure 4As shown, the directional bearing 11 consists of a bearing bracket 16 and a bearing 17. During use, the support column 5 is passed through the bearing bracket 16, and the directional bearing 11 is secured to the column 5 using the bearing bracket 16. Each directional bearing 17 is in perpendicular contact with the barrel 6, ensuring that the barrel 6 does not deflect in that direction. Furthermore, friction between the bearing 17 and the barrel 6 is minimized during the loading and unloading phases of the device to prevent vertical friction from affecting the test results.

[0046] In the present invention, other orientation devices may be used instead of the orientation bearing, and the present invention is not limited thereto.

[0047] The loading device for providing an in-situ stress state for a large indoor simulation device of an in-situ soil layer includes a loading console 14, a cooperative loading jack 7, a force sensor 12, and a displacement sensor 13. After setting the target force and displacement values ​​on the operating interface of the loading console 14, the loading console 14 will compare the target force and target displacement with the force and displacement measured by the force sensor 12 and the displacement sensor 13, and automatically control the lifting and lowering of the cooperative loading jack 7 below the bucket 6 with a measuring hole through the loading console 14, thereby driving the bucket 6 with a measuring hole to rise and fall; when the target force or target displacement set in the loading console 14 is equal to the force or displacement measured by the force sensor 12 and the displacement sensor 13, the cooperative loading jack 7 stops lifting and remains in the same position. During the loading and unloading process, the upper cover plate 2 with the variable diameter test hole and the variable diameter hole-bolt 3 and the variable diameter hole inner bolt 4 provide a reaction force to apply a vertical load to the soil sample, simulating the in-situ stress state of the soil layer.

[0048] During the loading and unloading process, multiple cooperative loading jacks 7 evenly arranged below the barrel with measuring holes 6 will move in coordination based on the displacement signal provided by the displacement sensor 13 to ensure that the bottom surface of the barrel with measuring holes 6 remains horizontal and the moving direction of the barrel with measuring holes 6 always remains vertical.

[0049] The present invention utilizes a coordinated loading method using multiple jacks to ensure the bucket's movement remains vertical, effectively reducing uneven soil stress distribution during loading and testing. The number of jacks employed can be varied based on specific working conditions, such as using a single jack or employing other loading devices in place of jacks. This is not a limitation of the present invention.

[0050] The installation process of a large indoor simulation device for in-situ soil layers is as follows:

[0051] (1) Place the foundation slab 8 on a site where the flatness and rigidity meet the requirements.

[0052] (2) Install the force sensor 12 into the co-loading jack 7. Place the co-loading jack 7 above the foundation base plate 8, ensuring that the top surface of the co-loading jack 7 is horizontal and the height is consistent.

[0053] (3) Place the material bucket 6 with the measuring hole on the top surface of the cooperative loading jack 7, and require that the center position of the material bucket 6 with the measuring hole be consistent with the center position of the foundation bottom plate 8.

[0054] (4) Pass the support column 5 through the lower positioning nut 9 and the base plate 8 in sequence, install the lower fastening nut 1 and tighten it, and then install the directional bearing 11 and the upper positioning nut 9 on the support column 5 in sequence. The present invention installs the directional bearing 11 on the support column 5, which can effectively prevent the device from tilting during installation, loading and testing.

[0055] (5) Pass the support column 5 through the upper cover plate 2 with the variable diameter test hole, place the upper cover plate 2 with the variable diameter test hole on the upper positioning nut 9, confirm that the upper cover plate 2 with the variable diameter test hole is in the same center position as the base plate 8, and tighten the fastening nut 1 on the upper part of the support column 5.

[0056] (6) Install the bolt 4 in the reducing hole into the bolt 3 with a hole in the reducing hole, and then install the bolt 3 with a hole in the reducing hole into the upper cover plate 2 with the reducing test hole.

[0057] (7) Tighten the measuring hole bolts 10 on the side wall of the barrel 6 with the measuring hole. The side wall of the barrel 6 of the present invention is provided with multiple sets of symmetrical measuring hole bolts 10, and corresponding sensors can be installed and arranged through the measuring holes according to the test requirements.

[0058] (8) Install the displacement sensor 13 to the outside of the cooperative loading jack 7.

[0059] (9) Connect the loading console 14 to the cooperative loading jack 7 , and then connect the force sensor 12 and the displacement sensor 13 to the loading console 14 .

[0060] (10) The loading condition of the collaborative loading jack 7 and the signals of the force sensor 12 and displacement sensor 13 are tested through the loading console 14 to complete the installation.

[0061] The present invention develops a large-scale indoor simulation device for in-situ soil layers and proposes corresponding test methods, which can realize the in-situ states of the density, stress, etc. of the in-situ soil layers in indoor simulated field tests. At the same time, it provides variable-diameter test holes and multiple measuring holes, which provide basic conditions for further carrying out indoor simulation tests of various field tests.

[0062] The present invention realizes precise control of soil sample density through layered sampling and a sampling method combining manual compaction and electric compaction, and can restore various soil density states from loose to dense.

[0063] Example 2

[0064] This embodiment provides a large-scale indoor simulation method for an on-site in-situ soil layer, which is applied to the large-scale indoor simulation device for an in-situ soil layer described in the first embodiment, and includes:

[0065] Remove the upper fastening nut 1 and the upper cover plate 2 with the variable-diameter test hole. Place a thin flexible sleeve 15 coated with a lubricant (such as petroleum jelly, carbon powder, etc.) inside the barrel 6, ensuring it fits snugly against the inner wall. Drill holes in the flexible sleeve 15 corresponding to the measurement holes on the barrel 6.

[0066] The test soil material is loaded into the material barrel 6 with a measuring hole in layers according to the preset relative density. After each layer is loaded, it is compacted using a compaction instrument, supplemented by watering when necessary, to restore the density of the in-situ soil layer. Manual compaction or electric compaction is used according to the density requirements of the soil sample. Manual compaction is used to prepare relatively loose soil samples, and a metal compactor is used to tamp the soil. Electric compaction is used to prepare relatively dense soil samples, and an electric mechanical compactor is used to tamp the soil. When compacting manually or using a small electric mechanical compactor, the compaction process follows the basic principle of from the outside to the inside. First, tamp along the inner wall of the material barrel 6 with a measuring hole for one circle, and then move the compactor inward and perform the next circle of compaction along the inner diameter of the compacted track. During this process, it is noted that the two compaction tracks should overlap by about 20% to ensure that the compaction range is fully covered. Repeat the above compaction process until it is compacted to the center of the material barrel 6 with a measuring hole, completing one round of compaction. Measure and compare whether the soil has been compacted to the specified height. If not, repeat the above steps for the next round of compaction until the specified height is reached, completing the compaction of one layer of soil. During this process, remove the corresponding measurement hole bolts 10 at the required position according to the test needs and arrange the sensors.

[0067] After the soil material in the material barrel 6 with the measuring hole is filled and compacted, the upper cover plate 2 with the variable diameter test hole is installed according to the hole position and aligned with the support column 5, and the upper fastening nut 1 is tightened.

[0068] According to the test requirements, appropriate bolts with holes 3 and bolts in holes 4 with variable diameter holes are selected and installed on the upper cover plate 2 with variable diameter test holes.

[0069] The collaborative loading jack 7 is started through the loading console 14, and the soil material is loaded to a preset stress state based on the signal of the force sensor 12 to complete the loading.

[0070] Remove the bolts 4 in the reducing holes or the bolts 3 with holes in the reducing holes as needed to conduct an indoor simulation test of the on-site in-situ test. After removing the bolts 4 in the reducing holes or the bolts 3 with holes in the reducing holes, assemble the on-site in-situ test equipment and set it up on the upper cover plate 2 with the reducing test holes so that the test soil for the indoor simulation test of the on-site in-situ test is located at the center of the bolts 4 in the reducing holes or the bolts 3 with holes in the reducing holes; conduct the simulation test according to the test operation requirements of the on-site in-situ test and record the test data; after the test, dismantle the on-site in-situ test equipment and reinstall the removed bolts 4 in the reducing holes or the bolts 3 with holes in the reducing holes on the upper cover plate 2 with the reducing test holes to complete the indoor simulation test of the on-site in-situ test.

[0071] After completing an indoor simulation test of an on-site in-situ test, the loading console 14 returns the cooperative loading jack 7 to its initial state based on the signal of the displacement sensor 13 .

[0072] Remove the upper fastening nut 1 and remove the upper cover 2 with the variable diameter test hole.

[0073] Remove the soil material and the flexible sleeve 15 from the material bucket 6 with the measuring hole, remove the sensor installed on the measuring hole of the material bucket 6 with the measuring hole, screw on the corresponding measuring hole bolt 10 and tighten it.

[0074] Align the upper cover plate 2 with the variable diameter test hole with the support column 5 according to the hole position, and tighten the upper fastening nut 1 to complete the shutdown.

[0075] The present invention has developed a large-scale indoor simulation device for in-situ soil layers and proposed a corresponding test method. On the premise of restoring the in-situ soil state on site, it provides variable diameter test holes and multiple measuring holes, providing basic conditions for further carrying out indoor simulation tests of various field tests. The indoor simulation tests of on-site in-situ tests that can be carried out in this device include: static penetration test, dynamic penetration test, standard penetration test, cross-plate shear test, lateral pressure test, shear wave velocity test, etc. According to the test soil size and sensor arrangement required for the on-site in-situ test indoor simulation test to be carried out, sensors are arranged at the measuring holes at appropriate positions, test holes of appropriate sizes are selected, and field test equipment is set up above the test holes to carry out different types of on-site in-situ test indoor simulation tests.

[0076] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A large-scale indoor simulation device for in-situ soil layers, characterized in that: include: A base plate, a material barrel with a measuring hole is connected to the base plate via a cooperative loading jack, a flexible sleeve is provided on the inner wall of the material barrel, and an upper cover plate with a variable diameter test hole is provided at the open end of the material barrel; support columns are used to penetrate the upper cover plate and the base plate and are fixed with nuts; A force sensor is provided inside the cooperative loading jack, and a displacement sensor is provided outside the cooperative loading jack. The cooperative loading jack, the force sensor and the displacement sensor are all connected to the loading console; The upper cover plate is provided with a reducing hole with a bolt, and the reducing hole with a bolt is provided inside the reducing hole; the reducing hole with a bolt can be removed alone or the reducing hole with a bolt and the reducing hole with a bolt can be removed together; A plurality of groups of measuring hole bolts are provided on the side wall of the barrel.

2. The large-scale indoor simulation device for in-situ soil layer according to claim 1, characterized in that: The support column is provided with a directional bearing, which includes a bearing bracket and a bearing. The support column passes through the bearing bracket, and the directional bearing is fastened to the support column by the bearing bracket. The bearing is in vertical contact with the outer wall of the barrel.

3. The large-scale indoor simulation device for in-situ soil layer according to claim 1, characterized in that: The center of the bolt in the reducing hole, the center of the bolt with a hole in the reducing hole and the center of the barrel are coaxial.

4. The large-scale indoor simulation device for in-situ soil layer according to claim 1, characterized in that: The support columns are fixed to the upper cover plate by using positioning nuts, and the support columns are fixed to the base bottom plate by using fastening nuts.

5. The large-scale indoor simulation device for in-situ soil layer according to claim 1, characterized in that: The flexible sleeve is also provided with a hole at a position corresponding to the opening of the barrel.

6. The large-scale indoor simulation device for in-situ soil layers according to claim 1, characterized in that: Lubricating material is applied between the flexible sleeve and the barrel.

7. A large-scale indoor simulation method for in-situ soil layers, characterized in that: A large-scale indoor simulation device for an in-situ soil layer according to any one of claims 1 to 6 is used, comprising: Place a thin flexible sleeve with a lubricating material on the outer wall into the barrel and fit it tightly against the inner wall of the barrel; according to the position of the measuring hole of the barrel, make a hole at the corresponding position of the flexible sleeve; The test soil material is loaded into the bucket with measuring holes in layers according to the preset relative density. After each layer is loaded, it is compacted using a compaction instrument to restore the density. After one round of compaction, it is measured and compared to see whether it has been compacted to the specified height. If not, the next round of compaction is carried out until the specified height is reached, completing the compaction of one layer of soil material. During this process, the corresponding measuring hole bolts are removed at the required locations according to the test needs and sensors are arranged. Install the upper cover plate, start the coordinated loading jack through the loading console, and load the soil material to the preset stress state according to the signal of the force sensor to complete the loading; Conduct indoor simulation tests for on-site in-situ testing.

8. The large-scale indoor simulation method of in-situ soil layer according to claim 7, characterized in that: The compaction process adopts manual compaction and electric compaction respectively according to the density requirements of the soil sample; when manual compaction or electric compaction is performed, the compaction process follows the basic principle of from outside to inside, first tamping along the inner wall of the barrel with the measuring hole, and then moving the compactor inward, and performing the next circle of compaction along the inner diameter of the compacted track. During the compaction process, the two compaction tracks should partially overlap to ensure that the compaction range is fully covered.

9. The large-scale indoor simulation method of in-situ soil layer according to claim 7, characterized in that: Before conducting indoor simulation tests, remove the bolts in the reducing holes or the bolts with holes in the reducing holes.

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