Transparent soil preparation method for visually simulating and demonstrating melting and seepage processes of ice-rich moraine soil

Abstract

The invention provides a transparent soil preparation method for visually simulating and demonstrating the melting and seepage process of ice-rich moraine soil, and belongs to the technical field of geotechnical engineering visual model tests. The preparation method comprises the following steps: preparing quartz glass particles; preparing a mixed liquid from white oil and n-dodecane; preparing a mixed liquid frozen block; preparing test soil from the mixed liquid, quartz glass particles and fused quartz sand; laying a test soil layer; laying a mixed liquid frozen block layer; repeatedly and alternately paving the test soil and the mixed liquid frozen blocks until the total thickness meets the test requirement; freezing at low temperature to obtain the transparent soil. The quartz glass particles, the fused quartz sand, the mixed liquid and the mixed liquid frozen blocks are used for simulating coarse gravels, sandy soil, pore fluid, buried ice and other components in the moraine-rich soil respectively, the refractive indexes of all the components are matched, and the technical problem that the melting and seepage process in the moraine-rich soil is difficult to visualize is solved; the method is of great significance to reveal a moraine soil internal structure degradation mechanism under the freezing and thawing effect.

Description

Technical Field

[0001] This invention relates to the field of visualization model testing technology in geotechnical engineering, and in particular to a method for preparing transparent soil that visualizes and simulates the melting and seepage process of ice-rich moraine. Background Technology

[0002] Glacial till is a loose soil type formed by the accumulation of debris carried by glaciers during glacial retreat, and is widely distributed in the Qinghai-Tibet Plateau region. Because it forms in a glacial environment, glacial till deposits often contain ice bodies and frozen materials of varying volumes, shapes, and sizes. When the ambient temperature rises, these internal frozen materials melt, leading to a decrease in the strength of the soil and rock mass, deformation, and displacement, becoming a significant contributing factor to geological disasters. Transparent soil, as an artificially synthesized soil and rock simulation material based on the principle of optical similarity, has the core advantage of overcoming the observational limitations of traditional physical model experiments using similar materials. Traditional similar materials struggle to capture the spatiotemporal evolution of deformation and failure processes within soil and rock media, hindering in-depth research into the constitutive relationships of soil and rock mechanics. Transparent soil technology, however, can visualize the multi-field coupling effects within soil and rock masses. However, currently, no feasible method has been proposed for preparing transparent soil that can visualize and simulate the melting and seepage process of ice-rich glacial till. Summary of the Invention

[0003] This invention aims to provide a transparent soil preparation method for visually simulating the melting and seepage process of ice-rich moraine. Quartz glass particles, fused silica sand, mixed liquid, and frozen blocks of mixed liquid are used to simulate components such as coarse gravel, sand, pore fluid, and buried ice in ice-rich moraine, respectively, and the refractive index of each component is matched. This solves the technical problem of visualizing the internal melting and seepage process of ice-rich moraine, and is of great significance for revealing the internal structural deterioration mechanism of moraine under freeze-thaw action.

[0004] The technical solution adopted in this invention is: A method for preparing transparent soil for visually simulating the melting and seepage process of ice-rich moraine includes the following steps: Step S1: Select rod-shaped quartz glass of different diameters and coarsely crush them into coarse particles to obtain quartz glass particles; wherein, the size of the quartz glass particles is determined by the test type; the test type is a general simulation test or a glacier field simulation test; Step S2: Mix white oil and n-dodecane at a volume ratio of 10:4, stir until homogeneous, and set aside as a liquid mixture. Step S3: Pour the mixed liquid into a freezing mold and freeze it at an ambient temperature ≤0℃ to obtain a frozen block of the mixed liquid; Step S4: Weigh the mixed liquid, quartz glass particles and fused quartz sand according to the required water content, rock content and sand content for the test, mix them thoroughly and prepare the test soil. Step S5: Lay a layer of the test soil in the transparent molded container to form a test soil layer; Step S6: According to the required ice content for the test, the mixed liquid frozen block is laid on the test soil to form a mixed liquid frozen block layer; Step S7: Repeat steps S5 and S6, alternately laying the test soil layer and the mixed liquid frozen block layer until the total thickness meets the test requirements; Step S8: At an ambient temperature ≤0℃, the transparent molded container and the test soil layer and the mixed liquid frozen block layer alternately laid inside it are subjected to low-temperature freezing to obtain transparent soil that visualizes and simulates the melting and seepage process of ice-rich moraine.

[0005] Furthermore, in step S2, after the mixed liquid is prepared, the refractive index of the mixed liquid is measured using an Abbe refractometer; If the refractive indices of the mixed liquid, the quartz glass particles, and the molten quartz sand are consistent, then let them stand directly. If the refractive indices of the mixed liquid, the quartz glass particles, and the fused silica sand are inconsistent, the ratio of the white oil to the n-dodecane is finely adjusted, and then the refractive indices are remeasured until the refractive indices of the mixed liquid, the quartz glass particles, and the fused silica sand are consistent. Finally, the mixture is allowed to stand.

[0006] Furthermore, in step S2, the settling time is ≥30 min.

[0007] Furthermore, in step S4, before the quartz glass particles and the molten quartz sand are mixed with the mixed liquid, the quartz glass particles and the molten quartz sand are respectively washed with distilled water, dried, and set aside for later use.

[0008] Furthermore, in step S5, the transparent molded container is made of plexiglass; And / or, in step S5, the transparent molded container is rectangular.

[0009] Furthermore, in step S7, steps S5 and S6 are repeated 3 to 5 times.

[0010] Furthermore, in step S7, when repeating steps S5 and S6, the thickness of each test soil layer is the same; And / or, in step S7, when repeating steps S5 and S6, the thickness of each layer of the mixed liquid frozen block is the same.

[0011] Furthermore, in step S3, during low-temperature freezing, the ambient temperature is -30 ℃ ≤ ambient temperature ≤ -25 ℃, and the time is ≥ 24 h; And / or, in step S8, during low-temperature freezing, the temperature is -30 ℃ ≤ ambient temperature ≤ -25 ℃, and the time is ≥ 24 h.

[0012] Furthermore, in step S8, the transparent soil, together with the transparent molding container, is placed in a transparent observation container filled with clean water, and the melting and seepage process of the simulated ice-rich moraine can be observed by a camera at room temperature.

[0013] Furthermore, the transparent observation container is made of plexiglass; And / or, the transparent observation container is rectangular.

[0014] The beneficial effects of this invention are: This invention provides a transparent soil preparation method for visually simulating the melting and seepage process of ice-rich moraine. Quartz glass particles, fused silica sand, mixed liquid, and frozen blocks of mixed liquid are used to simulate components such as coarse gravel, sand, pore fluid, and buried ice in ice-rich moraine, respectively. The method achieves refractive index matching of each component, which solves the technical problem of visualizing the internal melting and seepage process of ice-rich moraine. This method is of great significance for revealing the internal structural deterioration mechanism of moraine under freeze-thaw action. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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 based on these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating the transparent soil preparation method for visually simulating the melting and seepage process of ice-rich moraine in the embodiments.

[0017] Figure 2 A schematic diagram for observing the melting and seepage process of ice-rich moraine.

[0018] In the picture: 1- Transparent acrylic molded container; 2- Transparent acrylic observation container; 3- Clear water; 4- Mixed liquid frozen block layer; 5- Test soil layer; 6- High-speed camera. Detailed Implementation

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention.

[0021] The embodiments of the invention will now be described in detail with reference to the accompanying drawings.

[0022] This embodiment presents a method for preparing transparent soil that visualizes and simulates the melting and seepage process of ice-rich moraine. The process is shown in the attached figure. Figure 1 As shown in the figure. The preparation method includes the following steps: Step S1: Select rod-shaped quartz glass of different diameters and coarsely crush them into coarse particles using a hammer or crusher to obtain quartz glass particles. The size of the quartz glass particles is determined by the test type, which can be a general simulation test or a glacier field simulation test. General simulation tests primarily investigate the melting and seepage process of glacial moraine under various factors, such as different water contents, different rock (coarse gravel) contents, different ice contents, different sand contents, different rock particle sizes, and different sand particle sizes. By adjusting these factors, the melting and seepage process of glacial moraine under various conditions can be simulated. Glacier field simulation tests, on the other hand, study the melting and seepage process of glacial moraine in glacier fields, where the glacial moraine has specific water contents, rock contents, sand contents, and ice contents. On the one hand, in this embodiment, quartz glass particles and fused quartz sand are used to simulate coarse gravel and sand in glacial till, respectively. Both are made of the same material and have the same refractive index. On the other hand, since the coarse gravel in glacial till varies in diameter, if rod-shaped quartz glass of the same diameter is used, the diameter after coarse crushing may be relatively uniform. Therefore, in this embodiment, quartz glass particles obtained by coarse crushing with rod-shaped glass rods of different diameters are more non-uniform, which can better simulate the coarse gravel particles in natural glacial till.

[0023] Step S2: Mix white oil and n-dodecane at a volume ratio of 10:4, stir until homogeneous, and set aside as a mixed liquid.

[0024] Step S3: Pour the mixed liquid into a freezing mold and freeze it at an ambient temperature ≤0℃ to obtain a frozen block of the mixed liquid. In this embodiment, the mixed liquid and the frozen block of the mixed liquid are used to simulate the pore fluid and buried ice components in ice-rich moraine, respectively.

[0025] Step S4: Weigh the mixed liquid, quartz glass particles and fused quartz sand according to the required water content, rock content and sand content for the test, mix them thoroughly and prepare the test soil.

[0026] Step S5: Lay a layer of the test soil in the transparent molded container to form a test soil layer.

[0027] Step S6: According to the required ice content for the test, the mixed liquid frozen block is laid on the test soil to form a mixed liquid frozen block layer.

[0028] Step S7: Repeat steps S5 and S6, alternately laying the test soil layer and the mixed liquid frozen block layer until the total thickness meets the test requirements.

[0029] Step S8: At an ambient temperature ≤0℃, the transparent molded container and the test soil layer and the mixed liquid frozen block layer alternately laid inside it are subjected to low-temperature freezing to obtain transparent soil that visualizes and simulates the melting and seepage process of ice-rich moraine.

[0030] The beneficial effects of the above technical solutions are as follows: This embodiment provides a transparent soil preparation method for visually simulating and demonstrating the melting and seepage process of ice-rich moraine. Quartz glass particles, fused silica sand, mixed liquid, and frozen blocks of mixed liquid are used to simulate components such as coarse gravel, sand, pore fluid, and buried ice in ice-rich moraine, respectively, and the refractive index of each component is matched. This solves the technical problem that the internal melting and seepage process of ice-rich moraine is difficult to visualize, and is of great significance for revealing the internal structural deterioration mechanism of moraine under freeze-thaw action.

[0031] In the preferred embodiment, in step S2, after the mixed liquid is prepared, the refractive index of the mixed liquid is measured using an Abbe refractometer. If the refractive indices of the mixed liquid, the quartz glass particles, and the fused silica sand are consistent, it is allowed to stand directly. If the refractive indices of the mixed liquid, the quartz glass particles, and the fused silica sand are inconsistent, the ratio of white oil to n-dodecane is finely adjusted, and the refractive index is measured again until the refractive indices of the mixed liquid, the quartz glass particles, and the fused silica sand are consistent, and then it is allowed to stand. In this embodiment, the quartz glass particles and the fused silica sand have the same refractive index, and the refractive index of the mixed liquid prepared by white oil and n-dodecane is also the same as that of the quartz glass particles and the fused silica sand, thus achieving matching of the refractive indices of each component. Simultaneously, if there is a deviation in the refractive index of the mixed liquid prepared by white oil and n-dodecane, white oil or n-dodecane can be added according to the current refractive index, or the mixture can be prepared again with white oil and n-dodecane to maintain consistency in the refractive indices of the mixed liquid, the quartz glass particles, and the fused silica sand.

[0032] In the preferred embodiment, during step S2, the settling time is ≥30 min. Maintaining an appropriate settling time in this embodiment helps to remove air bubbles introduced by stirring and mixing in the liquid, thus avoiding their impact on the simulated melting and seepage process results.

[0033] In the preferred embodiment, in step S4, before the quartz glass particles and the fused silica sand are mixed with the liquid, the quartz glass particles and the fused silica sand are respectively washed with distilled water, dried, and set aside. In this embodiment, by washing and drying the quartz glass particles and the fused silica sand in advance, surface dust can be removed, which helps improve the accuracy of the simulation results.

[0034] In a preferred embodiment, in step S5, the transparent molded container is made of plexiglass; and / or, in step S5, the transparent molded container is rectangular. The transparent molded container in this embodiment is widely available and relatively inexpensive.

[0035] In the preferred embodiment, step S7 involves repeating steps S5 and S6 3 to 5 times. For example, in this embodiment, the steps are repeated 3 times, resulting in a total of eight layers: four test soil layers and four mixed liquid frozen block layers. This allows for a suitable visual simulation of the melting and seepage process of ice-rich moraine.

[0036] In the preferred embodiment, in step S7, when repeating steps S5 and S6, the thickness of each layer of the test soil is approximately the same; and / or, in step S7, when repeating steps S5 and S6, the thickness of each layer of the mixed liquid frozen block is approximately the same. By controlling the thickness of the test soil layer and the mixed liquid frozen block layer in this embodiment, ice-rich moraine can be better simulated, improving the accuracy of the simulation results.

[0037] In the preferred embodiment, during step S3, the low-temperature freezing period is -30 ℃ ≤ ambient temperature ≤ -25 ℃, and the time is ≥ 24 h; and / or, during step S8, the low-temperature freezing period is -30 ℃ ≤ ambient temperature ≤ -25 ℃, and the time is ≥ 24 h. Controlling the freezing temperature and freezing time in this embodiment helps to ensure the corresponding freezing effect.

[0038] In the preferred embodiment, in step S8, the transparent soil and the transparent molded container are placed in a transparent observation container filled with clean water, and the melting and seepage process of the simulated ice-rich moraine can be observed by a camera at room temperature.

[0039] In this preferred embodiment, the transparent observation container is made of plexiglass and is rectangular in shape. This transparent observation container is used to prevent moisture from condensing in direct contact with air at low temperatures, which would affect the visualization effect.

[0040] The following is a more specific example to illustrate this.

[0041] Test type: Standard simulation test The experimental simulation conditions required were: 15 wt% rock (particle size 3~10 mm) + 35 wt% sand (particle size 0.1~2 mm) + 10 wt% water + 40 wt% buried ice.

[0042] A method for preparing transparent soil that visualizes and simulates the melting and seepage process of ice-rich moraine is described below: (1) Select multiple rod-shaped quartz glass with a diameter of 5mm~10mm according to the rock content, crush them into coarse particles to obtain quartz glass particles; (2) The obtained quartz glass particles and molten quartz sand are washed with distilled water in sequence to remove surface impurities, and then placed in an oven for high-temperature drying to remove residual moisture; (3) Mix white oil and n-dodecane at a volume ratio of 10:4, stir until homogeneous to form a mixed liquid, and then let stand for 30 minutes; (4) The refractive index of the mixed liquid was determined by using an Abbe refractometer. By finely adjusting the ratio of white oil to n-dodecane, the refractive indices of the mixed liquid, quartz glass particles and fused silica sand were kept consistent. (5) Pour the prepared liquid mixture into a freezing mold (1cm*1cm*1cm) and then place it in a freezer (-25 ℃) for 24 h. (6) According to the water content set in the test requirements, mix the mixed liquid, quartz glass particles and fused quartz sand thoroughly to prepare the test soil; (7) Pour the prepared test soil into a rectangular transparent plexiglass molded container 1 (15cm*15cm*15cm) to form test soil layer 5 with a thickness of 1cm; (8) According to the ice content set in the test requirements, place the mixed liquid frozen block on top of the test soil in the transparent plexiglass molded container 1 to form a mixed liquid frozen block layer 4 with a thickness of 1cm; the test soil layer 5 and the corresponding mixed liquid frozen block layer 4 together form a layer of ice-rich moraine soil. (9) Repeat steps (7) and (8) to prepare the next layer of ice-rich moraine. The thickness of each test soil layer 5 and each mixed liquid frozen block layer 4 is 1 cm. Repeat 4 times until the total thickness of the ice-rich moraine reaches the test design requirements. (10) Place the transparent plexiglass molded container 1 containing the prepared simulated ice-rich moraine in a freezer (-25 ℃) and freeze for 24 h to obtain transparent soil; (11) Take out the frozen transparent plexiglass molded container 1, and place the transparent soil together with the transparent plexiglass molded container 1 into the rectangular transparent plexiglass observation container 2 (20cm*20cm*20cm) filled with water 3. Under normal temperature test conditions, let the transparent soil (i.e. simulated ice-rich moraine soil) melt. Pay attention to the liquid level of water 3 to prevent it from sinking into the transparent soil. (12) such as Figure 2 As shown, a high-speed camera 6 is placed directly in front of a transparent acrylic observation container 2 to observe the melting and seepage process inside the ice-rich moraine. The transparent acrylic observation container 2 is used to prevent the transparent acrylic molded container 1 at low temperatures from directly contacting the air and generating water vapor, which would affect the visualization effect.

[0043] This embodiment proposes a transparent soil preparation method for visually simulating and demonstrating the melting and seepage process of ice-rich moraine. The method is controllable and can accurately simulate the multiphase characteristics of ice-rich moraine, solving the problem of difficulty in observing its internal melting and seepage. It can be effectively applied to model test research on the freeze-thaw degradation mechanism of moraine.

Claims

1. A method for preparing transparent soil that visualizes and simulates the melting and seepage process of ice-rich moraine, characterized in that, Includes the following steps: Step S1: Select rod-shaped quartz glass of different diameters and coarsely crush them into coarse particles to obtain quartz glass particles; wherein, the size of the quartz glass particles is determined by the test type; the test type is a general simulation test or a glacier field simulation test; Step S2: Mix white oil and n-dodecane at a volume ratio of 10:4, stir until homogeneous, and set aside as a liquid mixture. Step S3: Pour the mixed liquid into a freezing mold and freeze it at an ambient temperature ≤0℃ to obtain a frozen block of the mixed liquid; Step S4: Weigh the mixed liquid, quartz glass particles and fused quartz sand according to the required water content, rock content and sand content for the test, mix them thoroughly and prepare the test soil. Step S5: Lay a layer of the test soil in the transparent molded container to form a test soil layer; Step S6: According to the required ice content for the test, the mixed liquid frozen block is laid on the test soil to form a mixed liquid frozen block layer; Step S7: Repeat steps S5 and S6, alternately laying the test soil layer and the mixed liquid frozen block layer until the total thickness meets the test requirements; Step S8: At an ambient temperature ≤0℃, the transparent molded container and the test soil layer and the mixed liquid frozen block layer alternately laid inside it are subjected to low-temperature freezing to obtain transparent soil that visualizes and simulates the melting and seepage process of ice-rich moraine.

2. The method for preparing transparent soil for visually simulating the melting and seepage process of glacial till rich in ice, as described in claim 1, is characterized in that... In step S2, after the mixed liquid is prepared, the refractive index of the mixed liquid is measured using an Abbe refractometer. If the refractive indices of the mixed liquid, the quartz glass particles, and the molten quartz sand are consistent, then let them stand directly. If the refractive indices of the mixed liquid, the quartz glass particles, and the fused silica sand are inconsistent, the ratio of the white oil to the n-dodecane is finely adjusted, and then the refractive indices are remeasured until the refractive indices of the mixed liquid, the quartz glass particles, and the fused silica sand are consistent. Finally, the mixture is allowed to stand.

3. The method for preparing transparent soil for visually simulating the melting and seepage process of ice-rich moraine soil according to claim 1, characterized in that, In step S2, the settling time is ≥30 min.

4. The method for preparing transparent soil for visually simulating the melting and seepage process of ice-rich moraine soil according to claim 1, characterized in that, In step S4, before the quartz glass particles and the molten quartz sand are mixed with the mixed liquid, the quartz glass particles and the molten quartz sand are washed with distilled water, dried, and set aside.

5. The method for preparing transparent soil for visually simulating and demonstrating the melting and seepage process of glacial till rich in ice, as described in claim 1, is characterized in that... In step S5, the transparent molded container is made of plexiglass. And / or, in step S5, the transparent molded container is rectangular.

6. The method for preparing transparent soil for visually simulating and demonstrating the melting and seepage process of ice-rich moraine soil according to claim 1, characterized in that, In step S7, steps S5 and S6 are repeated 3 to 5 times.

7. The method for preparing transparent soil for visually simulating and demonstrating the melting and seepage process of ice-rich moraine soil according to claim 1, characterized in that, In step S7, when repeating steps S5 and S6, the thickness of each test soil layer is the same; And / or, in step S7, when repeating steps S5 and S6, the thickness of each layer of the mixed liquid frozen block is the same.

8. The method for preparing transparent soil for visually simulating the melting and seepage process of glacial till rich in ice, as described in claim 1, is characterized in that... In step S3, during low-temperature freezing, the ambient temperature is -30 ℃ ≤ ambient temperature ≤ -25 ℃, and the time is ≥ 24 h; And / or, in step S8, during low-temperature freezing, the temperature is -30 ℃ ≤ ambient temperature ≤ -25 ℃, and the time is ≥ 24 h.

9. The method for preparing transparent soil for visually simulating and demonstrating the melting and seepage process of ice-rich moraine soil according to any one of claims 1 to 8, characterized in that, In step S8, the transparent soil and the transparent molding container are placed in a transparent observation container filled with clean water, and the melting and seepage process of the simulated ice-rich moraine can be observed by a camera at room temperature.

10. The method for preparing transparent soil for visually simulating the melting and seepage process of ice-rich moraine soil according to claim 9, characterized in that, The transparent observation container is made of plexiglass; And / or, the transparent observation container is rectangular.

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