Self-tamping type geotechnical centrifuge drainage consolidation test device and construction method thereof

Abstract

The application relates to a self-tamping type geotechnical centrifuge drainage consolidation test device and a construction method thereof, which comprises a model box, a reinforced support and a drainage hole; the model box is a rectangular structure with an upper opening and a closed periphery and bottom; the reinforced support frame is symmetrically arranged on the inner wall of the model box and divides the model box into an inner cavity and an outer cavity; the inner cavity is arranged with test soil bodies; and the outer cavity is arranged with sand; in the application, the drainage consolidation method discards the difficulties in the traditional consolidation method, such as difficult production and high technical precision requirement, and maximally plays the role of the geotechnical centrifuge, so that the centrifuge is significantly used in consolidation drainage.

Description

Technical Field

[0001] This invention relates to the field of consolidation testing devices, specifically to a self-compacting geocentrifuge drainage consolidation testing device and its construction method. Background Technology

[0002] The problem of drainage and consolidation of soft clay has been a persistent challenge worldwide. Common methods include vacuum preloading, surcharge preloading, and a combination of vacuum and surcharge preloading. However, these methods often suffer from slow drainage efficiency or uneven consolidation in practical applications due to the complexity of their drainage devices and the associated technical difficulties.

[0003] Geotechnical centrifuges are now widely used in geotechnical engineering due to their ability to replicate the stress and strain fields of scaled models into on-site prototypes through centrifugal acceleration. The traditional centrifuge drainage consolidation method involves centrifuging to compress the soil within the model chamber towards the bottom, while water, being lighter than soil, seeps out from the surface, thus achieving drainage and consolidation. However, this method has a limited capacity for water drainage, and once a certain degree of consolidation is achieved, it becomes difficult to drain more water. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a self-compacting geotextile centrifuge drainage consolidation test device, which is implemented by the following technical solution:

[0005] A self-compacting geotextile centrifuge drainage consolidation test device includes a model box, a reinforced support frame, and drainage holes; characterized in that: the model box is a rectangular structure with an open top and closed sides and bottom; the reinforced support frame is symmetrically arranged on the inner wall of the model box, dividing the model box into inner and outer cavities; the inner cavity contains test soil, and the outer cavity contains sand.

[0006] The bottom of the model box is equipped with shock-absorbing rubber, and several spring assemblies are installed inside the shock-absorbing rubber.

[0007] The reinforced support frame includes two fixed support frames at the front and rear and two movable support frames on the left and right. The fixed support frame includes a support plate and an aluminum alloy side panel. The movable support frame includes a telescopic component, an inclined panel and a flat plate. The aluminum alloy side panel is provided with wedge-shaped rubber at both ends.

[0008] The inclined panel is in contact with the wedge-shaped rubber via a telescopic component, and when extended, the inclined panel presses against the aluminum alloy side panel;

[0009] The model box is provided with fixing rods on the left and right inner walls, and the fixing rods are connected to the telescopic assembly.

[0010] The telescopic component is installed in conjunction with the holes in the inclined panel, and hydraulic adjustment is provided on the telescopic component;

[0011] Drainage holes are provided on both the aluminum alloy side panel and the bottom of the flat panel.

[0012] The aluminum alloy side panel is made of aerospace aluminum alloy. The support plate and the aluminum alloy side panel are welded together to keep them perpendicular to the support. The support plate is attached to the side wall and bottom of the model box.

[0013] The movable support frame includes a telescopic component, an inclined panel, and a flat plate, wherein wedge-shaped rubbers are provided at both ends of the aluminum alloy side panel from top to bottom; the inclined panel and the flat plate are welded into a trapezoidal component; the inclined panel and the wedge-shaped rubbers cooperate, and when the inclined panel moves outward, the wedge-shaped rubbers are continuously squeezed, so that the inclined panel and the aluminum alloy side panel maintain a tight fit and connection.

[0014] The thickness of both the support plate and the aluminum alloy side panel is 5mm, and the width of the support plate is 100mm.

[0015] The aluminum alloy side panel has drainage holes with a diameter of 2mm. There are at least three rows of drainage holes horizontally, with a horizontal spacing of 75mm and a vertical spacing of 60mm between each hole.

[0016] Geotextile is installed at the bottom drainage hole of the model box. The geotextile is pasted on the surface of the hole to prevent sand and soil from clogging the hole and obstructing the drainage flow.

[0017] The bottom of the model box is equipped with a magnetic steel plate assembly, which adopts the principle of mutual repulsion. The magnetic steel plate assembly is positioned above and below the shock-absorbing spring.

[0018] Another method for constructing a self-compacting geotextile centrifuge drainage consolidation test device is provided, characterized in that:

[0019] Step (1): According to the size of the geotechnical centrifuge model box, select a reinforced support that fits the side wall of the model box. First, assemble the model box, install the reinforced support frame and connect the drainage hole. After filling the bottom of the inner cavity with dry sand, fill the upper part with test soil. The height of the test soil should be at least half the height of the model box and the distance from the top of the model box should be no less than 15cm. The outer cavity should be filled with permeable coarse sand that is higher than the height of the drainage hole.

[0020] Step (2): After the model box has settled for a certain period of time, the telescopic components are adjusted so that the inclined panel is pressed against the aluminum alloy side panel through the telescopic components, which is beneficial to the sealing of the wedge-shaped rubber on the side and prevents water leakage from the side of the device when the centrifuge is in operation.

[0021] Step (3): Place the installed model box into a centrifuge to accelerate the consolidation. The specific consolidation time is determined according to the test requirements to prevent water seepage from the surface of the sand inside the support from overflowing the model box and causing damage to the centrifuge.

[0022] Step (4): After the operation is completed, stop the machine and use a vacuum pump or water pump to drain the water that has seeped out of the surface of the sand inside the support.

[0023] Step (5): Repeat steps (3) to (4) until the required degree of consolidation is achieved.

[0024] After adopting the above technical solution, the beneficial effects of the present invention are:

[0025] This drainage consolidation method overcomes the difficulties of traditional consolidation methods, such as difficult manufacturing and high technical precision requirements, and maximizes the role of the geotextile centrifuge, enabling the centrifuge to play a significant role in consolidation and drainage.

[0026] This drainage consolidation device is simple to manufacture, has a high reusability, and because the centrifugal force of the centrifuge on the soil is evenly distributed and the drainage holes are evenly arranged, the overall consolidation effect is also good.

[0027] This support device can be used as a reaction frame and can be used to install displacement sensors, truly achieving multiple uses in one device. By setting up telescopic components, it is beneficial for consolidation tests of various volume and cross-sectional dimensions. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 A schematic diagram of the test apparatus provided for an embodiment of this application;

[0030] Figure 2 A schematic plan view of the test apparatus provided for an embodiment of this application;

[0031] Figure 3 A top view of the test apparatus provided for an embodiment of this application;

[0032] Figure 4 A schematic diagram of the drainage hole provided for an embodiment of this application;

[0033] Figure 5 Drainage diagram provided for embodiments of this application;

[0034] Explanation of reference numerals in the attached figures:

[0035] 1-Reinforced support frame, 2-Test soil, 3-Sand, 4-Model box, 5-Drainage hole, 6-Geotextile, 7-Isolation rubber, 8-Magnetic steel plate assembly, 11-Fixed support frame, 12-Movable support frame, 111-Support plate, 112-Aluminum alloy side panel, 113-Wedge rubber, 121-Telescopic component, 122-Sloping panel, 123-Flat plate, 124-Fixing rod. Detailed Implementation

[0036] The following description of the embodiments will help the public to better understand the present invention. However, the specific embodiments provided by the applicant should not and should not be regarded as a limitation on the technical solution of the present invention. Any change to the definition of components or technical features, or any formal but not substantive transformation of the overall structure, should be regarded as the scope of protection defined by the technical solution of the present invention.

[0037] In this application, unless otherwise expressly specified or limited, the terms "installation," "connection," "fixation," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components; they can refer to mere surface contact; or they can refer to surface contact connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] This invention is achieved using the following technical solution:

[0039] like Figures 1-5 As shown in Embodiment 1, a self-compacting geotextile centrifuge drainage consolidation test device is provided, comprising a model box 4, a reinforced support frame 1, and a drainage hole 5; characterized in that: the model box is a rectangular structure with an open top and closed sides and bottom, the reinforced support frame is symmetrically arranged on the inner wall of the model box, and the model box is divided into inner and outer cavities, the inner cavity is filled with test soil 2, and the outer cavity is filled with sand 3;

[0040] The bottom of the model box is equipped with shock-absorbing rubber 7, and several spring assemblies are installed inside the shock-absorbing rubber;

[0041] The reinforced support frame includes two fixed support frames 11 at the front and rear and two movable support frames 12 on the left and right. The fixed support frame includes a support plate 111 and an aluminum alloy side panel 112. The movable support frame includes a telescopic component 121, an inclined panel 122 and a flat plate 123. The aluminum alloy side panel is provided with wedge-shaped rubber 113 at both ends.

[0042] The inclined panel is in contact with the wedge-shaped rubber via a telescopic component, and when extended, the inclined panel presses against the aluminum alloy side panel;

[0043] The model box is provided with fixing rods 124 on the left and right inner walls, and the fixing rods are connected to the telescopic assembly.

[0044] The telescopic component is installed in conjunction with the holes in the inclined panel, and hydraulic adjustment is provided on the telescopic component;

[0045] Drainage holes 5 are provided on both the aluminum alloy side panel and the bottom of the flat plate.

[0046] The aluminum alloy side panel is made of aerospace aluminum alloy. The support plate and the aluminum alloy side panel are welded together to keep them perpendicular to the support. The support plate is attached to the side wall and bottom of the model box.

[0047] The movable support frame includes a telescopic component, an inclined panel, and a flat plate, wherein wedge-shaped rubbers are provided at both ends of the aluminum alloy side panel from top to bottom; the inclined panel and the flat plate are welded into a trapezoidal component; the inclined panel and the wedge-shaped rubbers cooperate, and when the inclined panel moves outward, the wedge-shaped rubbers are continuously squeezed, so that the inclined panel and the aluminum alloy side panel maintain a tight fit and connection.

[0048] The thickness of both the support plate and the aluminum alloy side panel is 5mm, and the width of the support plate is 100mm.

[0049] The aluminum alloy side panel has drainage holes with a diameter of 2mm. There are at least three rows of drainage holes horizontally, with a horizontal spacing of 75mm and a vertical spacing of 60mm between each hole.

[0050] Geotextile 6 is installed at the bottom drainage hole of the model box. The geotextile is pasted on the surface of the hole to prevent sand and soil from clogging the hole and obstructing the drainage flow.

[0051] The bottom of the model box is equipped with a magnetic steel plate assembly 8, which adopts the principle of mutual repulsion. The magnetic steel plate assembly is positioned above and below the shock-absorbing spring.

[0052] Another method for constructing a self-compacting geotextile centrifuge drainage consolidation test device is provided, characterized in that:

[0053] Step (1): According to the size of the geotechnical centrifuge model box, select a reinforced support that fits the side wall of the model box. First, assemble the model box, install the reinforced support frame and connect the drainage hole. After filling the bottom of the inner cavity with dry sand, fill the upper part with test soil. The height of the test soil should be at least half the height of the model box and the distance from the top of the model box should be no less than 15cm. The outer cavity should be filled with permeable coarse sand that is higher than the height of the drainage hole.

[0054] Step (2): After the model box has settled for a certain period of time, the telescopic components are adjusted so that the inclined panel is pressed against the aluminum alloy side panel through the telescopic components, which is beneficial to the sealing of the wedge-shaped rubber on the side and prevents water leakage from the side of the device when the centrifuge is in operation.

[0055] Step (3): Place the installed model box into a centrifuge to accelerate the consolidation. The specific consolidation time is determined according to the test requirements to prevent water seepage from the surface of the sand inside the support from overflowing the model box and causing damage to the centrifuge.

[0056] Step (4): After the operation is completed, stop the machine and use a vacuum pump or water pump to drain the water that has seeped out of the surface of the sand inside the support.

[0057] Step (5): Repeat steps (3) to (4) until the required degree of consolidation is achieved.

[0058] In addition, in Embodiment 2, when the test model box is involved, the equipment for the drainage consolidation test is first determined to be a reinforced support test equipment, and the soil sample to be consolidated is Wenzhou soft clay with an initial moisture content of 70%. The internal dimensions of the model box are 850mm × 650mm × 650mm (length × width × height). The reinforced support frame includes two fixed support frames at the front and rear and two movable support frames on the left and right. The fixed support frames include support plates and aluminum alloy side panels, and the movable support frames include telescopic components, inclined panels, and flat plates.

[0059] The reinforced support frame is fabricated according to these dimensions. The aluminum alloy side panel dimensions are 640mm × 5mm × 650mm (length × thickness × height), and the support plate dimensions are 100mm × 5mm × 650mm (length × thickness × height). The movable support frame includes a 110mm × 5mm × 650mm (length × thickness × height) inclined panel and a 410mm × 5mm × 650mm (length × thickness × height) flat plate. The telescopic assembly is equipped with an electro-hydraulic mechanism. The drainage holes have a diameter of 2mm, with a horizontal spacing of 75mm and a vertical spacing of 60mm, arranged in two rows. The highest point of the drainage hole is 90mm away from the bottom of the model box. The surface of the holes is then covered with geotextile.

[0060] The test involves first placing a 100mm thick layer of Fujian standard sand (dry sand) in the inner cavity (test area). Then, a 400mm thick layer of soft clay for the test is placed on top of the sand. The same Fujian standard sand (dry sand) is placed in the outer cavity, with a sand layer height of 400mm.

[0061] Place the assembled model box into a geotextile centrifuge and run it at 100g for 1 hour. After the centrifuge is completed, stop the centrifuge and extract the water that has seeped into the support using a syringe. Then measure the settlement. If the expected settlement is not achieved, continue to place the model box into the centrifuge for consolidation, repeating steps four and five. After the expected settlement is achieved, test the undrained shear strength. Consolidation is complete once the desired degree of consolidation is reached.

[0062] Using the centrifugal force provided by the geotechnical centrifuge, the soil and water are squeezed towards the bottom of the model box. Due to the poor permeability of clay and the high permeability of sand, according to the seepage path shown in the diagram, the water squeezed out of the clay flows through the bottom sand to the sand in the surrounding support. The sand in the support has high permeability and its density is significantly greater than that of water, so it is stratified by the centrifugal force, and water seeps out from the surface of the sand.

[0063] The preferred 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 the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A self-compacting geotechnical centrifuge drainage consolidation test device, comprising a model box, a reinforced support frame, and drainage holes; the model box is a rectangular structure with an open top and closed sides and bottom, the reinforced support frame is symmetrically arranged on the inner wall of the model box, dividing the model box into inner and outer cavities, the inner cavity containing test soil, and the outer cavity containing sand. Its features are: The bottom of the model box is equipped with shock-absorbing rubber, and several spring assemblies are installed inside the shock-absorbing rubber; The reinforced support frame includes two fixed support frames at the front and rear and two movable support frames on the left and right. The fixed support frame includes a support plate and an aluminum alloy side panel. The movable support frame includes a telescopic component, an inclined panel and a flat plate. The aluminum alloy side panel is provided with wedge-shaped rubber at both ends. The inclined panel is in contact with the wedge-shaped rubber via a telescopic component, and when extended, the inclined panel presses against the aluminum alloy side panel; The model box is provided with fixing rods on the left and right inner walls, and the fixing rods are connected to the telescopic assembly. The telescopic component is installed in conjunction with the holes in the inclined panel, and hydraulic adjustment is provided on the telescopic component; Drainage holes are provided on both the aluminum alloy side panel and the bottom of the flat panel.

2. The self-compaction type geotechnical centrifuge drainage consolidation test device according to claim 1, characterized in that: The aluminum alloy side panel is made of aerospace-grade aluminum alloy.

3. The self-compaction type geotechnical centrifuge drainage consolidation test device according to claim 2, characterized in that: The movable support frame includes a telescopic component, an inclined panel, and a flat plate, wherein wedge-shaped rubbers are provided at both ends of the aluminum alloy side panel from top to bottom; the inclined panel and the flat plate are welded into a trapezoidal component; the inclined panel and the wedge-shaped rubbers cooperate, and when the inclined panel moves outward, the wedge-shaped rubbers are continuously squeezed, so that the inclined panel and the aluminum alloy side panel maintain a tight fit and connection.

4. The self-compaction type geotechnical centrifuge drainage consolidation test apparatus according to claim 2, characterized by: The thickness of both the support plate and the aluminum alloy side panel is 5mm, and the width of the support plate is 100mm.

5. The self-compaction type geotechnical centrifuge drain consolidation test device according to claim 1, characterized in that: The aluminum alloy side panel has drainage holes with a diameter of 2mm. There are at least three rows of drainage holes horizontally, with a horizontal spacing of 75mm and a vertical spacing of 60mm between each hole.

6. The self-compaction type geotechnical centrifuge drainage consolidation test apparatus according to claim 1, characterized in that: Geotextile is installed at the bottom drainage hole of the model box. The geotextile is pasted on the surface of the hole to prevent sand and soil from clogging the hole and obstructing the drainage flow.

7. The self-compaction type geotechnical centrifuge drainage consolidation test apparatus according to claim 1, characterized in that: The bottom of the model box is equipped with a magnetic steel plate assembly, which adopts the principle of mutual repulsion. The magnetic steel plate assembly is positioned above and below the spring assembly.

8. A construction method for a self-compacting geotextile centrifuge drainage consolidation test device according to any one of claims 1-7, characterized in that: Step (1): According to the size of the geotechnical centrifuge model box, select a reinforced support that fits the side wall of the model box. First, assemble the model box, install the reinforced support frame and set drainage holes. After filling the bottom of the inner cavity with dry sand, fill the upper part with test soil. The height of the test soil should be at least half the height of the model box and the distance from the top of the model box should be no less than 15cm. The outer cavity should be filled with permeable coarse sand that is higher than the height of the drainage holes. Step (2): After the model box has been left to stand for a certain period of time, the telescopic components are adjusted so that the inclined panel is pressed against the aluminum alloy side panel through the telescopic components, which is beneficial to the sealing of the wedge-shaped rubber on the side and prevents water leakage from the side of the device when the centrifuge is in operation. Step (3): Place the installed model box into a centrifuge to accelerate the consolidation. The specific consolidation time is determined according to the test requirements to prevent water seepage from the surface of the sand inside the support from overflowing the model box and causing damage to the centrifuge. Step (4): After the operation is completed, stop the machine and use a vacuum pump or water pump to drain the water that has seeped out of the surface of the sand inside the support. Step (5): Repeat steps (3) to (4) until the required degree of consolidation is achieved.

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