A seismic physical model material and a preparation method thereof

Abstract

The application belongs to the field of seismic physical model materials, and particularly relates to a seismic physical model material and a preparation method thereof. The seismic physical model material comprises, by weight, 100 parts of silicone rubber, 5-10 parts of a crosslinking agent, 2-4 parts of a catalyst, 1-10 parts of a high-molecular water-absorbing material and 10-50 parts of water; the high-molecular water-absorbing material is carboxymethyl cellulose. The physical model material obtained by the application has a longitudinal wave speed that increases from 1200 m / s to 2500 m / s and an attenuation factor that decreases from 0.050 to 0.020 with a decrease in temperature in the range of 20 DEG C to -20 DEG C, has similar physical properties to actual frozen soil layers, and can be used to simulate frozen soil layers. By controlling the weight ratio of the high-molecular water-absorbing material and the silicone rubber, different water contents of frozen soil layers can be quantitatively simulated, thereby laying a foundation for physical simulation research on frozen soil layers in plateau regions.

Description

Technical Field

[0001] This invention belongs to the field of earthquake physical model materials, and more specifically, relates to an earthquake physical model material and its preparation method. Background Technology

[0002] Earthquake physics simulation is a forward modeling technique that uses appropriate materials to create physical models of actual geological structures or bodies at a certain scale similarity ratio in a laboratory setting. Ultrasonic testing is then used to collect experimental data from field seismic exploration. To ensure that the physical model maintains consistency with the kinematic and dynamic characteristics of seismic wave propagation in actual geological structures and bodies, the velocity, density, attenuation, and other parameters of the physical model materials must first be proportional to those of the actual strata. Typically, the scale factor is 1:1 or 1:2. This is the fundamental principle of similarity in earthquake physics simulation technology.

[0003] Permafrost covers 25% of the total land area worldwide and is widely distributed in China. The P-wave velocity of pure water is approximately 1480 m / s, while that of frozen ice is approximately 3750 m / s, a significant change. At sub-zero temperatures, water freezes into ice, and the cementing effect of the ice crystals tightly binds soil particles together, forming a robust skeletal structure, resulting in substantial differences in the properties of the frozen soil. Therefore, the acoustic velocity, attenuation, and other physical properties of permafrost are closely related to temperature and water content. During exploration in high-altitude areas with near-surface permafrost, the physical properties of the permafrost layer significantly influence seismic wave propagation with seasonal changes. Typically, during summer and autumn, due to ice melting and water content, permafrost exhibits low acoustic velocity and high attenuation; conversely, during winter and spring, due to water freezing and ice content, it exhibits high acoustic velocity and low attenuation. Therefore, when conducting seismic physics simulations in plateau regions with permafrost, the first step is to develop model materials that exhibit the same physical properties as the permafrost in the field. Specifically, the model materials should have low velocity and high attenuation above 0°C, high velocity and low attenuation below 0°C, and their physical properties should change with temperature.

[0004] Currently, the materials used in earthquake physical models can be divided into two categories: solid industrial sheets and formable materials. Commonly used industrial sheets for physical model fabrication include aluminum, resin boards, plexiglass, and paraffin wax. By machining these industrial sheets, relatively accurate geometric structures can be obtained. Formable materials refer to mixtures of liquid or powdered materials that are solidified by adding a curing agent. These model materials possess good uniformity and plasticity, making it easy to fabricate complex structural physical models. However, existing model materials have two drawbacks: firstly, their physical properties do not change with temperature; secondly, current model materials are difficult to use for quantitative simulation of permafrost layers with different water contents. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned problems and provide a seismic physical model material whose physical properties change with temperature, and its preparation method. This invention utilizes a water-absorbing polymer material that, after absorbing water, exhibits either a gel-like state (above 0°C) or an ice-like state (below 0°C) with temperature changes, and whose physical properties are very close to those of water and ice, respectively, to simulate the phase and property changes of water in permafrost. The water-absorbing polymer material is uniformly dispersed in silicone rubber, and after curing, the model material exhibits different acoustic velocities and attenuation factors at different temperatures (20°C to -20°C). The P-wave velocity increases from 1200 m / s to 2500 m / s with temperature, while the attenuation factor decreases from 0.05 to 0.02. The model material exhibits physical property characteristics similar to actual permafrost zones: low velocity and high attenuation above 0°C, and high velocity and low attenuation below 0°C, making it suitable for simulating permafrost layers. In addition, by controlling the weight ratio of superabsorbent polymer to silicone rubber, it is possible to quantitatively simulate the water content of different permafrost layers, laying the foundation for seismic physical simulation research on plateau exploration with permafrost near the surface.

[0006] To achieve the above objectives, a first aspect of the present invention provides an earthquake physics model material comprising, by weight:

[0007] 100 parts silicone rubber, 5-10 parts crosslinking agent, 2-4 parts catalyst, 1-10 parts superabsorbent polymer, 10-50 parts water;

[0008] The superabsorbent polymer is carboxymethyl cellulose.

[0009] A second aspect of the present invention provides a method for preparing the above-described earthquake physical model material, the method comprising:

[0010] Step S1: Mixing the absorbent material: Mix the superabsorbent polymer material with water until homogeneous;

[0011] Step S2, Freezing the absorbent material: Freeze the material obtained in step S1;

[0012] Step S3, crushing the absorbent material: crush the material obtained in step S2;

[0013] Step S4, Material Mixing: Mix the silicone rubber, crosslinking agent, catalyst, and the material obtained in step S3 evenly;

[0014] Step S5, Vacuum treatment: Vacuum treatment is performed on the material obtained in step S4 to remove air bubbles from the material;

[0015] Step S6, Curing process: Place the material obtained in step S5 into the mold for curing, and then demold and remove it.

[0016] The seismic physical model material whose physical properties change with temperature and its preparation method provided by this invention have the following advantages:

[0017] (1) The physical properties of the material in the physical model of the present invention can change with temperature, the longitudinal wave velocity can increase from 1200m / s to 2500m / s, and the attenuation factor decreases from 0.05 to 0.02.

[0018] (2) The model material of the present invention has physical properties similar to those of the actual permafrost zone, with low velocity and large attenuation above 0°C and high velocity and small attenuation below 0°C, and can be used to simulate the permafrost layer.

[0019] (3) The model material of the present invention can quantitatively simulate different water contents of frozen soil by controlling the weight ratio of water-absorbing polymer material and silicone rubber.

[0020] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a method for preparing the earthquake physical model material of the present invention.

[0022] Figure 2 The graph shows the longitudinal wave velocity of the model material obtained in Example 1 as a function of temperature.

[0023] Figure 3 The graph shows the attenuation factor of the model material obtained in Example 1 as a function of temperature. Detailed Implementation

[0024] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0025] A first aspect of the present invention provides an earthquake physics model material comprising, by weight:

[0026] 100 parts silicone rubber, 5-10 parts crosslinking agent, 2-4 parts catalyst, 1-10 parts superabsorbent polymer, 10-50 parts water;

[0027] The superabsorbent polymer is carboxymethyl cellulose.

[0028] As a preferred embodiment, the silicone rubber is dimethyl silicone oil.

[0029] As a preferred embodiment, the crosslinking agent is a polysilicate crosslinking agent; as a further preferred embodiment, the crosslinking agent is ethyl polysilicate.

[0030] As a preferred embodiment, the catalyst is a low-toxicity or non-toxic organotin promoter; as a further preferred embodiment, the catalyst is stannous octoate.

[0031] As a preferred embodiment, the particle size of the superabsorbent polymer is 300-800 mesh, and as a further preferred embodiment, the particle size of the superabsorbent polymer is 600-800 mesh.

[0032] A second aspect of the present invention provides a method for preparing the above-described earthquake physical model material, the method comprising:

[0033] Step S1: Mixing the absorbent material: Mix the superabsorbent polymer material with water until homogeneous;

[0034] Step S2, Freezing the absorbent material: Freeze the material obtained in step S1;

[0035] Step S3, crushing the absorbent material: crush the material obtained in step S2;

[0036] Step S4, Material Mixing: Mix the silicone rubber, crosslinking agent, catalyst, and the material obtained in step S3 evenly;

[0037] Step S5, Vacuum treatment: Vacuum treatment is performed on the material obtained in step S4 to remove air bubbles from the material;

[0038] Step S6, Curing process: Place the material obtained in step S5 into the mold for curing, and then demold and remove it.

[0039] As a preferred embodiment, the preparation method of the above-mentioned earthquake physical model material satisfies at least one of the following conditions:

[0040] In step S2, the freezing temperature is -18 to -22°C, and the freezing time is 16 to 32 hours.

[0041] In step S3, the average particle size of the pulverized material is less than or equal to 1 mm;

[0042] In step S6, the curing temperature is 20-25℃ and the curing time is 16-32h.

[0043] The raw material information used in the embodiments and comparative examples of this invention is as follows:

[0044] Silicone rubber: Dimethyl silicone oil, Shanghai Xinguang Chemical Plant.

[0045] Crosslinking agent: Polyethyl silicate, Xuzhou Zhongyan Chemical Co., Ltd.

[0046] Catalyst: Stannous octoate, Wuhan Fuxinyuan Technology Co., Ltd.

[0047] Superabsorbent polymer: Example: Carboxymethyl cellulose, 800 mesh particle size, Hunan Hengyang Xiangwei Environmental Protection Technology Co., Ltd.; Comparative example: Water-absorbing resin, 800 mesh particle size, Wuhan Rongcan Biotechnology Co., Ltd.

[0048] In the embodiments and comparative examples of this invention, the number of parts refers to parts by weight.

[0049] Example 1

[0050] This embodiment provides an earthquake physical model material and its preparation method. See also: Figure 1 The preparation methods include:

[0051] Step S1: Mixing the absorbent material: Mix the superabsorbent polymer material with water and stir until evenly mixed;

[0052] Step S2, Freezing the absorbent material: Place the above-mixed absorbent material in a -20℃ freezer for 24 hours;

[0053] Step S3, crushing the absorbent material: Put the frozen absorbent material into a crusher and crush it until the average particle size is less than or equal to 1 mm;

[0054] Step S4, Material Mixing: Mix the silicone rubber, crosslinking agent, catalyst, and the pulverized freeze absorbent material from the above steps, and stir thoroughly and evenly.

[0055] Step S5, Vacuum treatment: Place all the raw materials obtained in the above steps into a vacuum machine and remove air bubbles from the materials;

[0056] Step S6, Curing process: Apply petroleum jelly to the inside of the mold as a release agent, put all the raw materials obtained in the above steps into the mold, place the mold at room temperature to cure for 24 hours, and then demold to complete the model material production.

[0057] Examples 2-8

[0058] The steps in Examples 2-8 are the same as those in Example 1, except that the amount of each component is different. The specific amount of each substance is shown in Table 1.

[0059] Comparative Example 1

[0060] Comparative Example 1 did not add any superabsorbent polymer or water. Each step was the same as steps S4-S6 in Example 1. The specific amounts of each substance are shown in Table 1.

[0061] Comparative Examples 2-6

[0062] The difference from Examples 2-6 is that other superabsorbent polymers are used.

[0063] Test case

[0064] The model materials obtained in Examples 1-8 and Comparative Examples 1-6 were placed in constant temperature chambers at different temperatures. The longitudinal wave velocity of the model materials was measured using the ultrasonic transmission method, and the Q value of the model materials was calculated using the spectral ratio method. The reciprocal 1 / Q was taken as the attenuation factor of the model materials. The test results are shown in Table 1. Figure 2 The graph shows the longitudinal wave velocity of the model material obtained in Example 1 as a function of temperature. Figure 3 The graph shows the attenuation factor of the model material obtained in Example 1 as a function of temperature.

[0065] Table 1

[0066]

[0067]

[0068] Example 1 mainly illustrates that, when the water-absorbing material is constant, the obtained physical model material can exhibit linear changes in longitudinal wave velocity and attenuation factor within the temperature range of 20℃ to -20℃, and has physical properties similar to those of actual frozen soil.

[0069] Examples 2-8 mainly illustrate that by controlling the weight ratio of the superabsorbent polymer to the silicone rubber, different water contents of frozen soil layers can be quantitatively simulated. The resulting physical model material can increase the longitudinal wave velocity from 1200 m / s to 2500 m / s as the temperature decreases within the range of 20°C to -20°C, while the attenuation factor decreases from 0.050 to 0.020.

[0070] Comparative Example 1 shows that without the addition of a superabsorbent polymer, the wave velocity and attenuation factor of the model material do not change with temperature.

[0071] Comparative Examples 2-6 correspond to Examples 2-6. The main point is that when the amount of water-absorbing resin added in the comparative examples gradually increases, the wave velocity and attenuation factor do not change regularly, and the velocity change range is small. Therefore, it is impossible to quantitatively simulate the water content of the frozen soil layer and does not have the effect produced by carboxymethyl cellulose.

[0072] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A material for earthquake physical modeling, characterized in that, The materials in this earthquake physical model include, by weight: 100 parts silicone rubber, 5-10 parts crosslinking agent, 2-4 parts catalyst, 1-10 parts superabsorbent polymer, 10-50 parts water; The superabsorbent polymer is carboxymethyl cellulose; The method for preparing the earthquake physical model material includes the following steps: Step S1: Mixing the absorbent material: Mix the superabsorbent polymer material with water until homogeneous; Step S2, Freezing the absorbent material: Freeze the material obtained in step S1; Step S3, crushing the absorbent material: crush the material obtained in step S2; Step S4, Material Mixing: Mix the silicone rubber, crosslinking agent, catalyst, and the material obtained in step S3 evenly; Step S5, Vacuum treatment: Vacuum treatment is performed on the material obtained in step S4 to remove air bubbles from the material; Step S6, Curing process: Place the material obtained in step S5 into the mold for curing, and then remove it from the mold; the curing temperature is 20~25℃.

2. The earthquake physical model material according to claim 1, wherein, The silicone rubber is dimethyl silicone oil.

3. The earthquake physical model material according to claim 1, wherein, The crosslinking agent is a polysilicate crosslinking agent.

4. The earthquake physical model material according to claim 3, wherein, The crosslinking agent is polyethylene silicate.

5. The earthquake physical model material according to claim 1, wherein, The catalyst is a low-toxicity or non-toxic organotin accelerator.

6. The earthquake physical model material according to claim 5, wherein, The catalyst is stannous octoate.

7. The earthquake physical model material according to claim 1, wherein, The particle size of the superabsorbent polymer is 300-800 mesh.

8. The earthquake physical model material according to claim 7, wherein, The particle size of the superabsorbent polymer is 600-800 mesh.

9. A method for preparing earthquake physical model material according to any one of claims 1-8, characterized in that, The preparation method includes: Step S1: Mixing the absorbent material: Mix the superabsorbent polymer material with water until homogeneous; Step S2, Freezing the absorbent material: Freeze the material obtained in step S1; Step S3, crushing the absorbent material: crush the material obtained in step S2; Step S4, Material Mixing: Mix the silicone rubber, crosslinking agent, catalyst, and the material obtained in step S3 evenly; Step S5, Vacuum treatment: Vacuum treatment is performed on the material obtained in step S4 to remove air bubbles from the material; Step S6, Curing process: Place the material obtained in step S5 into the mold for curing, and then remove it from the mold; the curing temperature is 20~25℃.

10. The method for preparing earthquake physical model material according to claim 9, wherein, The preparation methods of the above-mentioned earthquake physical model materials satisfy at least one of the following conditions: In step S2, the freezing temperature is -18 to -22°C, and the freezing time is 16 to 32 hours. In step S3, the average particle size of the pulverized material is less than or equal to 1 mm; In step S6, the curing time is 16~32h.

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