A drainage system and method for a geotechnical model box of a drum centrifuge

Abstract

The application provides a kind of for drum centrifuge geotechnical model box's water supplementing and draining system and method, comprising: soil sample holding chamber, for accommodating test soil sample and installing test geotechnical model;Water storage cavity, independent of each other with soil sample holding chamber;Two-way water flow structure, between soil sample holding chamber and water storage cavity;Water supplementing and draining structure, in communication with water storage cavity, according to water storage pool water volume to increase or decrease water volume;Through two-way water flow structure, water storage cavity and water supplementing and draining structure, in combination with different acceleration directions, realize water circulation, complete the discharge or supply of water to test soil sample in soil sample holding chamber.The application can be directly modified on the basis of existing geotechnical model box, without external power input, utilize the centrifugal force generated in geotechnical centrifugal model test process to realize water circulation, water storage cavity accumulates water discharged by soil sample during soil sample preparation process, while realizing the backflow of accumulated water and supplementing water to soil sample from the bottom during model test process, to ensure its full saturation.

Description

Technical Field

[0001] This invention relates to the field of geotechnical centrifuge model testing technology in marine geotechnical engineering, specifically to a drainage system and method for a geotechnical model box in a drum centrifuge. Background Technology

[0002] In marine geotechnical engineering, the properties of soil are primarily determined by its in-situ stress level. Due to the anisotropic and nonlinear characteristics of soil materials, conventional small-scale geotechnical model tests under one times gravity acceleration are insufficient to accurately reproduce the in-situ stress level of the soil, often resulting in distorted test results. Geotechnical centrifuge modeling technology, however, places a scaled-down geotechnical model in a high-speed rotating centrifuge. The centrifugal inertial frame compensates for the model's weight loss due to the scaling effect, thereby simulating the in-situ stress level of the soil. In recent years, geotechnical centrifuge model testing technology has been widely applied to solve complex geotechnical engineering problems and has attracted widespread attention from researchers both domestically and internationally.

[0003] In marine geotechnical engineering, actual soil is usually saturated. Therefore, a water supply system needs to be designed to meet the experimental requirements during geotechnical centrifuge model tests. Furthermore, the direction of acceleration changes during the operation and shutdown of the drum centrifuge: when shut down, the acceleration is vertically downwards (gravitational acceleration); while during operation, the acceleration is outwards along the radius of the centrifuge's rotation (hypergravity acceleration). Therefore, the water supply system used in the experiment must be highly adaptable to these changes in acceleration direction.

[0004] In existing technical documentation for geotechnical centrifuge model testing, an independent water supply system is typically used. However, this system has several drawbacks: 1. Setting up an independent water supply system within the working space of a drum centrifuge may lead to weight imbalance during the test; 2. An independent water supply system occupies the working space inside the drum centrifuge, directly affecting the size of the geotechnical model box that can be accommodated, thus encroaching on usable test space and limiting the scale of the test; 3. While an independent water supply system is effective in ensuring the saturation of the soil sample surface, existing model boxes often have perforated drainage pipes at the bottom. Under high centrifugal force, water in the soil sample will flow directly out through these pipes. Therefore, the existing independent water supply system can only ensure the saturation of the soil surface inside the model box, while the saturation of the soil at the bottom of the model box cannot be guaranteed, leading to distorted test results. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide a drainage system and method for a geotextile model box for a drum centrifuge.

[0006] According to one aspect of the present invention, a water supply and drainage system for a geotextile box of a drum centrifuge is provided, comprising:

[0007] A soil sample holding chamber, which is a cavity used to hold and prepare test soil samples and install geotechnical models required for the test;

[0008] A water storage chamber, which is independent of the soil sample holding chamber, is used for water storage;

[0009] A two-way water flow structure is provided between the soil sample holding chamber and the water storage chamber;

[0010] A water supply and drainage structure is connected to the water storage chamber and adjusts the water volume according to the existing water volume in the water storage tank.

[0011] Through the bidirectional water flow structure, water storage chamber, and water replenishment and drainage structure, combined with the different acceleration directions when the drum centrifuge starts and stops, water circulation is achieved, completing the drainage or replenishment of water for the test soil sample located in the soil sample holding chamber.

[0012] Preferably, the soil sample holding chamber and water storage cavity are composed of: a model box, wherein the model box has a drawer-shaped structure;

[0013] The drainage board is L-shaped and is placed inside the model box at a distance from it. The enclosed space formed by the model box and the drainage board is the water storage chamber. The open space formed by the model box and the drainage board is the soil sample holding chamber. The drainage board has water inlet and outlet holes and is equipped with a water inlet plug to form the water inlet and outlet structure. The vertical part of the drainage board has an array of bidirectional drainage holes to provide bidirectional water flow as the bidirectional water flow structure.

[0014] Preferably, the drainage board is further provided with a baffle, which can block the water flowing out of the soil surface due to the change in acceleration direction after the drum centrifuge stops, and prevent it from flowing into the drum centrifuge and damaging the equipment.

[0015] Preferably, it further includes a support strip, which is disposed between the model box and the drainage board to ensure the stability of the drainage board.

[0016] Preferably, one side of the support bar is flush with the ground, and the other side has a comb-like structure that allows water to flow through and buffers the water hammer effect caused by a sudden stop of the drum centrifuge. The model box has a groove. The flush side is fixed to the drainage plate, and the comb-like structure is inserted into the matching groove.

[0017] Preferably, it also includes geotextiles, which cover the inner wall of the soil sample container to block soil particles.

[0018] Preferably, the model box is fixed to the drainage board with bolts, and waterproof adhesive is applied during the installation of the bolts to ensure water tightness.

[0019] Preferably, a sealing strip is provided between the model box and the drainage plate, and between the groove and the support strip.

[0020] According to a second aspect of the present invention, a method for replenishing and draining soil samples is provided, employing the above-described replenishment and drainage system for a drum centrifuge geomancy box, comprising:

[0021] S1, fill the soil sample container with a saturated test soil sample. At this time, the acceleration direction is vertically downward and no water is accumulated in the water storage chamber.

[0022] S2, start the drum centrifuge and use the centrifugal inertia of the soil to consolidate the test soil sample and simulate its in-situ stress level. At this time, the acceleration direction is outward along the radius of the drum centrifuge's rotation circle. The water discharged during the soil consolidation process flows into the water storage chamber through the bidirectional water flow structure and accumulates.

[0023] S3, After the test soil is consolidated, the drum centrifuge is turned off. At this time, the acceleration direction is vertically downward, and the water in the water storage chamber flows downward to the bottom of the water storage chamber.

[0024] S4. Adjust the water volume as needed based on the accumulated water volume through the water supply and drainage structure;

[0025] S5. Install the geotechnical model for the test and start the drum centrifuge. At this time, the acceleration direction is outward along the radius of the drum centrifuge's rotation circumference. The accumulated water flows to the upper part of the water storage chamber under the action of centrifugal force and replenishes the test soil sample through the bidirectional water supply and drainage holes to ensure its saturation.

[0026] S6, turn off the drum centrifuge. At this time, the acceleration direction is downward. The water in the water storage chamber flows into the bottom of the water storage chamber under the action of gravity and accumulates. The residual water is discharged through the water supply and drainage structure.

[0027] Preferably, the adjustment of water volume as appropriate includes:

[0028] When the water volume in the water storage chamber is insufficient to fill the water storage chamber on the back of the soil sample during the operation of the drum centrifuge, the water volume needs to be increased through the water supply and drainage structure.

[0029] When the amount of water in the water storage chamber far exceeds the amount of water required to fill the water storage chamber on the back of the soil sample during the operation of the drum centrifuge, the amount of water needs to be reduced through a water replenishment and drainage structure.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The water replenishment and drainage system for the geotechnical model box of the drum centrifuge in this embodiment of the invention can be directly modified from the existing geotechnical model box. At the same time, no external power input is required. The centrifugal force generated during the geotechnical centrifuge model test is used to realize water circulation. The water storage chamber accumulates the water discharged from the soil sample during the soil sample preparation process. At the same time, the accumulated water is returned during the model test and water is replenished from the bottom of the soil sample to ensure that it is fully saturated.

[0032] 2. The water supply and drainage system and method for the geotechnical model box of the drum centrifuge in the embodiments of the present invention are applicable and economical. With the structure of the drum centrifuge, the present invention can realize the basic function of the independent water supply device and overcome the defects of the independent water supply device, such as unbalanced counterweight, encroachment on usable test space, and inability to guarantee the saturation of the soil at the bottom of the model box. Attached Figure Description

[0033] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0034] Figure 1 This is a schematic diagram of the drainage system for the geotechnical model box of a drum centrifuge in an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram showing the disassembled drainage system for the geotechnical model box of a drum centrifuge in an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the L-shaped porous drainage board with baffles connected to the comb-shaped support strip in the drainage system of the geotechnical model box for a drum centrifuge according to an embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of the outer shell of the model box for the water supply and drainage system of the geotechnical model box for a drum centrifuge in an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the bottom plate of the model box for the water supply and drainage system of the geotechnical model box for a drum centrifuge in an embodiment of the present invention;

[0039] Figure 6 This is a schematic diagram of an L-shaped porous drainage board with baffles used in the water supply and drainage system of a geotechnical model box for a drum centrifuge in an embodiment of the present invention.

[0040] Figure 7 This is a schematic diagram of the acceleration direction of the water supply and drainage system for the geotechnical model box of the drum centrifuge before and during the test, as described in an embodiment of the present invention.

[0041] Figure 8 This is a flowchart of a water replenishment and drainage method according to an embodiment of the present invention;

[0042] In the diagram: 1 is the outer shell of the model box, 2 is the bottom plate of the model box, 3 is the drainage board, 4 is the geotextile, 5 is the drain plug, 6 is the comb-shaped support strip connected to the bottom plate of the model box, 7 is the comb-shaped support strip connected to the outer shell of the model box, 8 is the bolt connecting the L-shaped perforated drainage board with baffle to the outer shell of the model box, 9 is the bolt connecting the L-shaped perforated drainage board with baffle to the bottom plate of the model box, 10 is the bolt connecting the outer shell of the model box to the bottom plate of the model box, 11 is the elastic sealing strip, 12 is the groove, 13 is the bolt hole, 14 is the bidirectional drain hole, 15 is the drain hole, 16 is the soil sample, and 17 is the geotechnical model. Detailed Implementation

[0043] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0044] This invention provides an embodiment of a water replenishment and drainage system for a geotechnical model box in a drum centrifuge, comprising: a soil sample holding chamber, a water storage chamber, a bidirectional water flow structure, and a water replenishment and drainage structure. The soil sample holding chamber is a cavity used to hold and prepare test soil samples and to install the geotechnical model required for the test. The water storage chamber is independent of the soil sample holding chamber and is used for water storage. The bidirectional water flow structure is located between the soil sample holding chamber and the water storage chamber. The water replenishment and drainage structure is connected to the water storage chamber and adjusts the water volume according to the existing water level in the storage chamber. Through the bidirectional water flow structure, the water storage chamber, and the water replenishment and drainage structure, combined with the different acceleration directions during the start-up and shutdown of the drum centrifuge, water circulation is achieved, completing the drainage or replenishment of water from the test soil samples.

[0045] The system in this embodiment only requires simple modifications to the existing geotechnical model box. It does not require external power input and uses the centrifugal force generated during the geotechnical centrifugal model test to achieve water circulation. This allows the water discharged from the soil sample to be accumulated during soil sample preparation, and the accumulated water is returned and the soil sample is replenished with water during the model test to ensure that it is fully saturated.

[0046] See Figure 1 This is a preferred embodiment of the present invention. In this embodiment, the water supply and drainage system for the geotextile model box of a drum centrifuge includes a model box and a drainage board 3. The model box is shaped like a rectangular drawer. The drainage board 3 is placed inside the model box and spaced apart from it, forming a closed space and an open space. The closed space serves as a water storage chamber, and the open space serves as a soil sample storage chamber. A water supply and drainage hole 15 is opened at the drainage board 3 and equipped with a stopcock 5, which serves as the water supply and drainage structure. The vertical part of the drainage board 3 is covered with bidirectional water supply and drainage holes 14.

[0047] The existing water supply system needs to be improved. Figure 7 The drum centrifuge shown has an additional independent water supply system within its internal working space. This not only leads to uneven weight distribution within the drum centrifuge but also directly affects the size of the geotechnical model box it can accommodate, thus impacting the scale of the experiment. This embodiment, however, places the water supply system directly inside the geotechnical model box, directly avoiding the aforementioned problems of uneven weight distribution and space encroachment.

[0048] It should be noted that the above-described structural configuration of the model box and drainage board is only one implementation of the soil sample holding chamber, water storage chamber, bidirectional water flow structure, and water supply and drainage structure. It is not limited to other structural forms of the soil sample holding chamber, water storage chamber, bidirectional water flow structure, and water supply and drainage structure in other embodiments.

[0049] See Figure 2 In a preferred embodiment, the model box is constructed by combining a model box shell 1 and a model box bottom plate 2. The drainage plate 3 is L-shaped and has a baffle. The baffle's function is to block water flowing from the soil surface due to the change in acceleration direction after the drum centrifuge stops, preventing it from flowing into the drum centrifuge and damaging the equipment. The water supply and drainage hole 15 is located at the baffle, lower than the model box bottom plate 2, and communicates with the water storage chamber.

[0050] See Figure 2 In a preferred embodiment, a geotextile 4 is provided in the soil sample holding chamber, which covers the inner wall of the soil sample holding chamber to prevent soil particles from entering the water storage chamber.

[0051] See Figure 2 and Figure 3 In a preferred embodiment, a plurality of comb-shaped support strips 7 connected to the outer shell of the model box are provided between the drainage plate 3 and the outer shell 1 of the model box; and a plurality of comb-shaped support strips 6 connected to the bottom plate of the model box are provided between the drainage plate 3 and the bottom plate 2 of the model box. These support strips can provide support and ensure the stability of the drainage plate 3.

[0052] See Figure 2 , Figure 3 , Figure 4 and Figure 6 Furthermore, both types of support bars described above have a comb-like structure, meaning one side is flat and the other side is serrated. To accommodate the shape of this support bar, several grooves 12 are formed in both the outer shell 1 and the bottom plate 2 of the model box. The flat side of the support bar is welded to the drainage plate 3, and the comb-like structure is inserted into the grooves 12 for fixation. The structural design of the support bar in this embodiment allows water flow and can buffer the water hammer effect caused by the sudden stop of the drum centrifuge.

[0053] See Figure 4 , Figure 5 and Figure 6 To ensure airtightness, in other embodiments of the present invention, elastic sealing strips 11 are provided at the connection between the outer shell 1 and the bottom plate 2 of the model box, at the connection between the drainage plate 3 and the outer shell 1 and the bottom plate 2 of the model box, and at the engagement point between the groove 12 and the support strip. For ease of distinction, they are referred to in sequence as the outer shell elastic sealing strip, the drainage plate sealing strip, the bottom plate elastic sealing strip, and the groove structure sealing strip.

[0054] See Figure 2 The outer shell 1 of the model box is connected to the bottom plate 2 of the model box by bolts 10, and the drainage plate 3 is connected to the outer shell 1 of the model box by bolts 8. The drainage plate 3 is also connected to the bottom plate 2 of the model box by bolts 9. Waterproof glue must be applied during the installation of the above bolts to ensure the water tightness of the device.

[0055] Furthermore, the width of the outer shell elastic sealing strip on the model box outer shell 1 is the same as the thickness of the model box outer shell 1; the width of the bottom plate elastic sealing strip on the model box bottom plate 2 is the same as the thickness of the model box bottom plate 2; the width of the groove structure sealing strip is the same as the size of the groove 12; and the width of the drainage plate elastic sealing strip is the same as the thickness of the drainage plate 3. The height of the outer shell elastic sealing strip, the bottom plate elastic sealing strip, the groove structure sealing strip, and the drainage plate sealing strip is 2-5mm. The elastic sealing strip 11 can be made of rubber or polyurethane. In some other embodiments, the elastic sealing strip 11 can also be made of other materials, as long as it can achieve the same function as in the embodiments of the present invention.

[0056] To ensure the rigidity of the device and its stability under high acceleration, the dimensions of the model box shell 1 and the model box bottom plate 2 are determined by the size of the geotechnical model box that the drum centrifuge can accommodate; the dimensions of the L-shaped porous drainage plate 3 with baffles are determined by the size of the cavity formed by the model box shell and the model box bottom plate; the thickness of the model box shell 1, the model box bottom plate 2, the L-shaped porous drainage plate with baffles 3, the comb-shaped support plate, and the size of the fixing bolts are determined by the speed and acceleration of the drum centrifuge; the model box shell, the model box bottom plate, the L-shaped porous drainage plate with baffles, the comb-shaped support plate, and the fixing bolts are made of high-strength stainless steel or aluminum alloy.

[0057] In other embodiments, a method for assembling a water supply and drainage system for a geotextile model box for a drum centrifuge is also provided, see [link to documentation]. Figure 1 - Figure 6 The specific process is as follows:

[0058] First, the L-shaped porous drainage plate 3 with baffle is connected by a comb-shaped support strip 6 that is welded to the bottom plate of the model box and a comb-shaped support strip 7 that is connected to the outer shell of the model box.

[0059] Second, the welded L-shaped porous drainage plate 3 with baffle is fixed to the model box shell 1 by bolts 9. During this process, waterproof glue needs to be applied to the bolts 9 and bolt holes 13.

[0060] Third, the model box bottom plate 2 and the assembled model box outer shell 2 are fixed with bolts 10 by connecting the model box outer shell and the model box bottom plate. During this process, waterproof glue needs to be applied to the bolts 10 and bolt holes 13.

[0061] Fourth, fix the model box bottom plate 2 and the L-shaped porous drainage plate 3 with baffles to the model box bottom plate with bolts 9. During this process, waterproof glue needs to be applied to the bolts 9 and bolt holes 13.

[0062] Fifth, geotextile 4 is laid in the external cavity formed by the outer shell 1 of the model box, the bottom plate 2 of the model box, and the L-shaped porous drainage board 3 with baffle.

[0063] Sixth, tighten the drain plug 5 at drain hole 15.

[0064] Based on the same inventive concept, in another embodiment, a method for replenishing and draining soil samples is provided, employing the aforementioned replenishment and drainage system for a drum centrifuge geotextile box; the process is described below. Figure 8 ,include:

[0065] S1, fill the soil sample container with a saturated test soil sample, at which point the acceleration direction is vertically downward;

[0066] S2, start the drum centrifuge and use the centrifugal inertia of the soil to consolidate the test soil sample and simulate its in-situ stress level. At this time, the acceleration direction is outward along the radius of the drum centrifuge's rotation circle. The water discharged during the soil consolidation process flows into the water storage chamber through the bidirectional water flow structure and accumulates.

[0067] S3, After the test soil is consolidated, the drum centrifuge is turned off. At this time, the acceleration direction is vertically downward, and the water in the water storage chamber flows downward to the bottom of the water storage chamber.

[0068] S4. Adjust the water volume as needed based on the accumulated water volume through the water supply and drainage structure;

[0069] S5, Install the test geotechnical model and start the drum centrifuge. At this time, the acceleration direction is outward along the radius of the drum centrifuge's rotation circumference. The accumulated water flows to the upper part of the water storage chamber under the action of centrifugal force and replenishes the test soil sample with water through the bidirectional water supply and drainage holes to ensure its saturation.

[0070] S6, turn off the drum centrifuge. At this time, the acceleration direction is downward. The water in the water storage chamber flows into the bottom of the water storage chamber under the action of gravity and accumulates. The residual water is discharged through the water supply and drainage structure.

[0071] The method in this embodiment is applicable and economical. It incorporates the structure of a drum centrifuge and can achieve the basic functions of an independent water supply device, overcoming the problems of unbalanced counterweights and encroachment on usable test space inherent in independent water supply devices. Furthermore, by adjusting the water volume, the water storage chamber at the back of the soil sample is filled with water during the operation of the drum centrifuge, preventing water from draining outwards. This inward replenishment of water from the back of the soil sample overcomes the deficiency in existing technologies that cannot guarantee the saturation of the soil at the bottom of the model box.

[0072] In other embodiments, combined with Figure 1 - Figure 6 It provides further refined methods for water replenishment and drainage of soil samples, the specific process of which is as follows:

[0073] First, before the experiment begins, saturated soil sample 16 is filled into the space formed by geotextile 4. At this time, the direction of acceleration is as follows: Figure 7 The direction of acceleration is shown when the machine stops.

[0074] Second, start the drum centrifuge and use the geotechnical centrifugal inertial frame to perform consolidation loading on test soil sample 16, simulating its in-situ stress level. At this time, the acceleration direction is as follows: Figure 7 As shown in the direction of acceleration during operation, the water discharged during the soil consolidation process flows through the bidirectional drainage hole 14 into the upper part of the internal cavity formed by the outer shell 1 of the model box, the bottom plate 2 of the model box, and the L-shaped porous drainage plate 3 with baffle, and accumulates there.

[0075] Third, after the soil at step 16 has been consolidated, the drum centrifuge is turned off. At this time, the direction of acceleration is as follows: Figure 7 As shown in the direction of acceleration when the machine stops, the water accumulated in the second cavity flows into the lower part of the internal cavity formed by the outer shell 1 of the model box, the bottom plate 2 of the model box, and the L-shaped porous drainage plate 3 with baffles under the action of gravity and accumulates there.

[0076] Fourth, by connecting a water supply pipe with a bend in the water supply and drainage hole 15, the water volume can be increased or decreased as appropriate according to the water volume accumulated in the third stage, and the plug 5 of the water supply and drainage hole can be tightened.

[0077] Fifth, install the test geotechnical model 17 and start the drum centrifuge. At this time, the direction of acceleration is as follows: Figure 7 As shown in the direction of acceleration during operation, the water accumulated in the fourth layer flows to the upper part of the internal cavity formed by the outer shell 1 of the model box, the bottom plate 2 of the model box, and the L-shaped porous drainage plate 3 with baffle under the action of centrifugal force, and replenishes the soil sample 16 with water through the bidirectional water replenishment and drainage holes 14 to ensure its saturation.

[0078] Sixth, after the experiment, turn off the drum centrifuge. At this time, the direction of acceleration is as follows: Figure 7 When the machine stops, the direction of acceleration is shown. The upward backflow of water in the fifth stage flows into the lower part of the internal cavity formed by the model box shell 1, the model box bottom plate 2 and the L-shaped porous drainage plate 3 with baffle under the action of gravity and accumulates. The water remaining in the device can be extracted through the water supply and drainage hole 15.

[0079] Expanding the testing capabilities of existing instruments using the above methods is of great significance in overcoming the shortcomings of current testing equipment.

[0080] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention. The above preferred features can be used in any combination without conflict.

Claims

1. A water supply and drainage system for a geotextile model box of a drum centrifuge, characterized in that, include: A soil sample holding chamber, which is a cavity used to hold and prepare test soil samples and install geotechnical models required for the test; A water storage chamber, which is independent of the soil sample holding chamber, is used for water storage; A two-way water flow structure is provided between the soil sample holding chamber and the water storage chamber; A water supply and drainage structure is connected to the water storage chamber and adjusts the water volume according to the existing water volume in the water storage tank. Through the water storage chamber, the bidirectional water flow structure, and the water replenishment and drainage structure, combined with the different acceleration directions when the drum centrifuge starts and stops, water circulation is achieved, completing the drainage or replenishment of water for the test soil sample located in the soil sample holding chamber; The soil sample storage chamber and the water storage chamber are composed of: A model box, wherein the model box has a drawer-like structure; The drainage board is L-shaped and is placed inside the model box at a distance from it. The enclosed space formed by the model box and the drainage board is the water storage chamber. The open space formed by the model box and the drainage board is the soil sample holding chamber. The drainage board has water inlet and outlet holes and is equipped with a water inlet plug to form the water inlet and outlet structure. The vertical part of the drainage board has an array of bidirectional drainage holes to provide bidirectional water flow, which is the bidirectional water flow structure. The drainage board is also equipped with a baffle, which can block the water flowing out of the soil surface due to the change in acceleration direction after the drum centrifuge stops, and prevent it from flowing into the drum centrifuge and damaging the equipment.

2. The water supply and drainage system for a geotextile model box for a drum centrifuge according to claim 1, characterized in that, It also includes a support bar, which is disposed between the model box and the drainage board to ensure the stability of the drainage board.

3. The water supply and drainage system for a geotextile model box for a drum centrifuge according to claim 2, characterized in that, One side of the support bar is flush with the ground, and the other side is a comb-like structure that allows water to flow through and buffers the water hammer effect caused by the sudden stop of the drum centrifuge. The model box has a groove. The flush side is fixed to the drainage plate, and the comb-like structure is inserted into the matching groove.

4. The water supply and drainage system for a geotextile model box for a drum centrifuge according to claim 1, characterized in that, It also includes geotextiles, which cover the inner walls of the soil sample container to block soil particles.

5. A water supply and drainage system for a geotextile model box for a drum centrifuge according to claim 1, characterized in that, The model box is fixed to the drainage board with bolts, and waterproof glue is applied during the installation of the bolts to ensure water tightness.

6. A water supply and drainage system for a geotextile model box for a drum centrifuge according to claim 3, characterized in that, A sealing strip is provided between the model box and the drainage plate, and between the groove and the support strip.

7. A method for replenishing and draining soil samples, characterized in that, The water supply and drainage system for a geotextile box for a drum centrifuge, as described in any one of claims 1-6, comprises: S1, fill the soil sample container with a saturated test soil sample. At this time, the acceleration direction is vertically downward and no water is accumulated in the water storage chamber. S2, start the drum centrifuge and use the centrifugal inertia of the soil to consolidate the test soil sample and simulate its in-situ stress level. At this time, the acceleration direction is outward along the radius of the drum centrifuge's rotation circle. The water discharged during the soil consolidation process flows into the water storage chamber through the bidirectional water flow structure and accumulates. S3, After the test soil is consolidated, the drum centrifuge is turned off. At this time, the acceleration direction is vertically downward, and the water in the water storage chamber flows downward to the bottom of the water storage chamber. S4. Adjust the water volume as needed based on the accumulated water volume through the water supply and drainage structure; S5. Install the geotechnical model for the test and start the drum centrifuge. At this time, the acceleration direction is outward along the radius of the drum centrifuge's rotation circumference. The accumulated water flows to the upper part of the water storage chamber under the action of centrifugal force and replenishes the test soil sample through the bidirectional water supply and drainage holes to ensure its saturation. S6, turn off the drum centrifuge. At this time, the acceleration direction is downward. The water in the water storage chamber flows into the bottom of the water storage chamber under the action of gravity and accumulates. The residual water is discharged through the water supply and drainage structure.

8. A method for replenishing and draining soil samples according to claim 7, characterized in that, The discretionary increase or decrease of water volume includes: When the water volume in the water storage chamber is insufficient to fill the water storage chamber on the back of the soil sample during the operation of the drum centrifuge, the water volume needs to be increased through the water supply and drainage structure. When the amount of water in the water storage chamber exceeds the amount of water required to fill the water storage chamber on the back of the soil sample during the operation of the drum centrifuge, the amount of water needs to be reduced through the water replenishment and drainage structure.

Images