Device and method for dynamically measuring size of hollow cylinder sample

Abstract

The invention discloses a device and a method for dynamically measuring the size of a hollow cylinder sample, and relates to the technical field of soil tests. The device comprises a sample bearing assembly, a conduit assembly, a saturated medium assembly, a transparent container, a height measuring unit and a liquid level measuring unit. The sample bearing assembly comprises a permeable stone ring, a base, an annular top cap and a waterproof film and is used for supporting and sealing a sample. The conduit assembly is communicated with the inner side of the sample for water injection and liquid level observation. And the saturated medium assembly realizes medium supply and suction in the sample saturation process. The transparent container accommodates the sample system. The height measuring unit monitors axial deformation of the sample, and the liquid level measuring unit synchronously monitors liquid level changes inside and outside the sample. According to the method, the initial inner diameter can be directly and accurately measured before the sample is saturated, the inner diameter, the outer diameter and the height change are synchronously measured in real time in the saturation process, the defect that a traditional method depends on an empirical formula and indirect estimation is overcome, and the size measurement precision and the test data reliability are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of geotechnical testing technology, specifically to a device and method for dynamic measurement of the dimensions of a hollow cylindrical specimen. Background Technology

[0002] In soil mechanics experimental research, the hollow cylindrical torsion-shear test can be used to study the mechanical properties of hollow cylindrical specimens under complex triaxial loads such as principal stress axis deflection. To accurately determine the porosity of the specimen and the conversion between stress and strain, it is necessary to accurately measure the dimensions of the specimen before loading (after saturation and consolidation).

[0003] However, existing measuring devices can only indirectly estimate the initial inner diameter of the sample after preparation based on the mold size and diaphragm thickness, lacking direct and accurate measurement methods. During the sample saturation stage, existing measuring devices cannot independently monitor the changes in the inner and outer diameters in real time, relying only on the empirical formula that volumetric strain equals three times the axial strain, based on the assumption of isotropic deformation. This leads to significant deviations in the assessment of the actual volume change of the sample, usually overestimating the volume change of the sample during the saturation process. At the same time, due to the small internal space of the sample and the need to avoid interfering with subsequent test processes, existing devices cannot simultaneously and dynamically acquire independent change data of the inner diameter, outer diameter, and height of the sample during the saturation process without affecting the sample's state. This results in inaccurate initial state parameters of the sample and distorted evaluation of volumetric deformation during the saturation process, which in turn affects the reliability of subsequent stress and strain calculations, ultimately reducing the effectiveness and engineering guidance value of the entire geotechnical test data. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for dynamic measurement of the dimensions of hollow cylindrical specimens, so as to solve the above-mentioned problems.

[0005] The technical solution of this invention is: A dynamic measurement device for the dimensions of a hollow cylindrical sample includes: a sample support assembly comprising: a permeable stone ring, a base, an annular cap, and a water-resistant membrane; the permeable stone ring includes an upper stone ring and a lower stone ring respectively abutting both ends of the sample; the base abuts the lower end face of the lower stone ring, and the base has a channel one and a channel two communicating with the inner side of the sample, and a channel three communicating with the lower stone ring; the annular cap abuts the upper end face of the upper stone ring, and the annular cap has a channel four at one end communicating with the upper stone ring; the water-resistant membrane includes a water-resistant membrane one and a water-resistant membrane two, the two ends of the water-resistant membrane one being fixedly connected to the outer sides of the annular cap and the base respectively, and the water-resistant membrane... The two ends of the membrane are fixedly connected to the inner sides of the annular top cap and the base, respectively; the conduit assembly includes a conduit one at the other end of the connecting channel one and a conduit two at the other end of the connecting channel two, the upper ends of the conduit one and the conduit two being higher than the lower end face of the upper stone ring; the saturated medium assembly includes a supply assembly at the other end of the connecting channel three and a suction assembly at the other end of the connecting channel four; a transparent container for containing the sample carrying assembly and the sample; a height measuring unit for measuring the axial displacement of the annular top cap; and a liquid level measuring unit including a first measuring component for measuring the liquid level height outside the sample and a second measuring component for measuring the liquid level height inside the sample.

[0006] Furthermore, a groove is provided on the upper surface of the base, and the groove is connected to channel one and channel two. The outer diameter and inner diameter of the annular top cap, the permeable stone ring, and the base are all the same, wherein the inner diameter of the base refers to the inner diameter of the groove provided on its upper surface.

[0007] Furthermore, the second conduit is a transparent tube, and the second conduit has a lower scale that is at the same height as the upper end face of the lower stone ring, and an upper scale that is at the same height as the lower end face of the upper stone ring.

[0008] Furthermore, the first conduit and the second conduit have the same inner diameter and are arranged parallel to each other in the vertical direction.

[0009] Furthermore, both channel three and channel four are provided in multiples and are symmetrically distributed along the circumference of the sample.

[0010] Furthermore, the supply component is a degassing water supply container; the suction unit includes a degassing water collection container equipped with a vacuum pump, and the degassing water collection container is connected to the channel four via a conduit four.

[0011] Furthermore, the first measuring component includes: a float plate one floating on the outer liquid surface of the sample and a corresponding laser displacement sensor one; the second measuring component includes: a float plate two floating on the inner liquid surface of the sample and a corresponding laser displacement sensor two, the annular top cap having a central hole for the laser to pass through; the height measuring unit is a dial indicator.

[0012] Furthermore, it also includes a support frame located on one side of the transparent container and having a crossbeam suspended above the transparent container. The laser displacement sensor one, the laser displacement sensor two, and the dial indicator are all fixed to the crossbeam of the support frame.

[0013] A method for dynamically measuring the dimensions of a hollow cylindrical sample, using the aforementioned apparatus, includes the following steps: Measurement of the inner diameter of the sample before saturation: Inject de-aired water through conduit one until the liquid level in conduit two is level with the upper end of the lower stone ring; this process is called the first stage of water injection. Inject de-aired water through conduit one until the liquid level in conduit two is level with the lower end of the upper stone ring; this process is called two-stage water injection. The water injection volume in the two-stage water injection is Q. The water volume in the portion of conduit one located between the upper and lower stone rings is Q1, and the water volume in the portion of conduit two located between the upper and lower stone rings is Q2. The sample height before saturation is h0, the sample inner diameter before saturation is 2r0, and the thickness of the water-resistant membrane is m. Q, Q1, Q2, and h0 are first obtained through measurement and calculation, and then the equation Q - Q1 - Q2 = π(r0 - m) is applied. 2 h0, calculate 2r0; Measurement of sample height, inner diameter, and outer diameter during saturation process: Pour degassing water into the inside of the transparent container until the liquid level is between the upper end face of the upper stone ring and the outer port of channel four of the annular top cap; pour degassing water into the inside of the sample until the liquid level is above the upper end face of the upper stone ring; ensure that the liquid level on both the inside and outside of the sample is always higher than the upper end face of the upper stone ring in subsequent processes. The supply component provides carbon dioxide gas, and the suction component draws in the carbon dioxide gas; subsequently, the supply component provides degassed water, and the suction component draws in the degassed water; during this process, the height measurement unit and the liquid level measurement unit measure Δh1, Δh2, and Δh3 respectively; the sample height during the saturation process is h. t The inner diameter of the sample is 2r t The outer diameter of the sample is 2R t The outer diameter of the sample before saturation is 2R0, the outer diameter of the annular cap, permeable stone ring, and base is 2R1, the inner diameter of the annular cap, permeable stone ring, and base is 2r1, the inner diameter of the transparent container is 2r2, and the thickness of the water-resistant membrane is m; according to the equation: h t =h0+△h3; (πr2 2 -π(R1+m) 2 )△h1=π(R t +m) 2 (h0+△h3)-π(R0+m) 2 h0; π(r1-m)2 △h2=π(r0-m) 2 h0-π(r t -m) 2 (h0+△h3); h was calculated t ,2r t and 2R t .

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes a channel and conduit assembly connected to the inner side of the sample, combined with precise liquid level control and water injection metering, to achieve direct and accurate determination of the initial inner diameter of the sample, eliminating the reliance on empirical measurements of mold dimensions and diaphragm thickness. During sample saturation, the coordinated operation of the liquid level measurement unit and the height measurement unit enables synchronous, dynamic, and non-contact monitoring of the inner diameter, outer diameter, and height. This accurately reflects the deformation of the sample during saturation and effectively corrects the volume change assessment bias caused by empirical formulas based on the isotropic assumption. Furthermore, the measurement units are all located outside the sample, preventing sensors from intruding into the sample's internal space, ensuring the sample's natural state and experimental integrity during testing. This significantly improves the accuracy and reliability of the initial inner diameter and three-dimensional dimension measurements during saturation, providing a solid data foundation for determining the porosity ratio, stress-strain analysis, and studying the mechanical properties of samples under complex loads in geotechnical testing. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention when measuring the initial inner diameter of the sample.

[0016] Figure 2 This is a schematic diagram of the structure of the present invention when measuring the inner diameter, outer diameter and height of a sample during the saturation process.

[0017] Figure 3 This is a schematic diagram of the path of the laser emitted from the laser displacement sensor.

[0018] Figure 4 This is a schematic diagram of the permeable stone ring viewed from above.

[0019] Figure 5 for Figure 4 A cross-sectional view along the AA direction.

[0020] Among them, 1. Conduit 1, 2. Conduit 2, 3. Laser displacement sensor 1, 4. Support, 5. Channel 4, 6. Upper stone ring, 7. Base, 8. Lower stone ring, 9. Transparent container, 10. Channel 3, 11. Channel 1, 12. Airless water collection container, 13. Vacuum pump, 14. Ring top cap, 15. Dial gauge, 16. Airless water supply container, 17. Float 2, 18. Float 1, 19. Laser displacement sensor 2, 20. Channel 2, 21. Conduit 3, 22. Conduit 4, 23. Conduit 5, 24. Lower scale, 25. Upper scale. Detailed Implementation

[0021] The following is combined with Figures 1 to 5 The specific embodiments of the present invention will be described in detail below. In the description of the present invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] Example like Figure 1 and Figure 2 As shown, a dynamic measurement device for the size of a hollow cylindrical sample includes: a sample carrying assembly, a conduit assembly, a saturated medium assembly, a transparent container 9, a height measuring unit, and a liquid level measuring unit. The sample carrying assembly includes: a permeable stone ring, a base 7, an annular cap 14, and a water-resistant membrane. The permeable stone ring includes: an upper stone ring 6 and a lower stone ring 8 that abut against both ends of the sample; the base 7 abuts against the lower end face of the lower stone ring 8, and the base 7 is provided with a first channel 11 and a second channel 20 communicating with the inner side of the sample, and a third channel 10 communicating with the lower stone ring 8; the annular cap 14 abuts against the upper end face of the upper stone ring 6, and the annular cap 14 has a fourth channel 5 that communicates with the upper stone ring 6 at one end; the water-resistant membrane includes a first water-resistant membrane and a second water-resistant membrane, the two ends of the first water-resistant membrane being fixedly connected to the outer sides of the annular cap 14 and the base 7, respectively, and the two ends of the second water-resistant membrane being fixedly connected to the inner sides of the annular cap 14 and the base 7, respectively. like Figure 1 and Figure 2As shown, the conduit assembly includes a conduit 1 at the other end of a connecting channel 11 and a conduit 2 at the other end of a connecting channel 20. The upper ends of both conduit 1 and conduit 2 are higher than the lower end face of the upper stone ring 6. The saturated medium assembly includes a supply assembly at the other end of the connecting channel 3 10 and a suction assembly at the other end of the connecting channel 4 5; a transparent container 9 is used to hold the sample carrying assembly and the sample; a height measuring unit is used to measure the axial displacement of the annular cap 14; and a liquid level measuring unit includes a first measuring assembly for measuring the liquid level height outside the sample and a second measuring assembly for measuring the liquid level height inside the sample.

[0024] For the initial dimensions of the sample after preparation, by injecting degassed water into conduit 1, according to the principle of communicating vessels, the liquid levels in the sample cavity, conduit 1, and conduit 2 are equal. During the stage where the liquid level rises from the upper end of the lower stone ring 8 to the lower end of the upper stone ring 6, there exists an equality relationship: the total amount of degassed water flowing into conduit 1 is equal to the increase in degassed water in the sample cavity, the sum of the increase in degassed water in conduit 1 and the increase in degassed water in conduit 2. The increase in degassed water in the sample cavity is equal to the volume of the sample cavity, which can be written as an algebraic expression about the sample's inner diameter. Substituting this algebraic expression into the above equality relationship yields an equation about the sample's inner diameter, which, when solved, gives the initial inner diameter of the sample.

[0025] For the sample saturation process, degassing water needs to be injected into the transparent container 9, and degassing water should also be added inside the sample to ensure that the liquid level on both the inner and outer sides of the sample is higher than the top surface of the upper stone ring. Then, carbon dioxide and degassing water are injected sequentially into the conduit 21 through the supply assembly, and carbon dioxide and degassing water are sequentially drawn away through the suction assembly to complete the sample saturation process. During the sample saturation process, there are the following equality relationships: 2. The increase in volume of the equivalent cylinder corresponding to the outer surface of the sample is equal to the increase in degassing water in the cylindrical space between the upper stone ring 6, the annular cap 14, and the transparent container 9; 3. The decrease in volume of the equivalent cylinder corresponding to the inner surface of the sample is equal to the increase in degassing water in the cylindrical space inside the upper stone ring 6 and the annular cap 14; 4. The height of the sample is equal to the sum of the initial height of the sample and the change in the sample height. In equality relationship 2, the increase in volume of the equivalent cylinder corresponding to the outer surface of the sample can be written as an algebraic expression about the outer diameter of the sample. In equation three, the decrease in volume of the equivalent cylinder corresponding to the inner surface of the sample can be written as an algebraic expression about the inner diameter of the sample. By simultaneously establishing equations two and four, and equation three and four, the outer and inner diameters of the sample during the saturation process can be obtained.

[0026] In the first equation of quantity, the total amount of degassing water flowing into conduit 1 can be obtained in various ways. For example, the data can be obtained by installing a flow meter, or by observing the change in the volume reading of the degassing water in the container supplying the degassing water.

[0027] In the first equation of quantity, the increase in the amount of airless water in tube 1 involves the inner diameter of tube 1 and the length of the corresponding increase in the airless water section. Both can be measured directly, and the inner diameter of tube 1 can also be obtained by consulting the product parameters of tube 1. The same applies to tube 2.

[0028] In the first equal quantity relationship, the increase in the amount of airless water in the inner cavity of the sample is related to the initial height of the sample, and the corresponding data can be directly measured.

[0029] In the second equality relationship, the increase in volume of the equivalent cylinder corresponding to the outer surface of the sample involves the height of the sample. This height is equal to the sum of the initial height of the sample and the change in the height of the sample. The change in the height of the sample can be measured by a dial gauge 15. The sum of the two can be used to obtain the height of the sample.

[0030] In the second equation, the increase in the amount of airless water in the cylindrical ring space between the upper stone ring 6, the annular cap 14, and the transparent container 9 involves the changes in the outer diameters of the upper stone ring 6 and the annular cap 14, the inner diameter of the transparent container 9, and the height of the airless water surface on the outside of the sample. The outer diameters of the upper stone ring 6 and the annular cap 14, and the inner diameter of the transparent container 9 can be measured directly or obtained by consulting the product parameters. The change in the height of the airless water surface on the outside of the sample can be measured using component one.

[0031] In the third equality relationship, the volume reduction of the equivalent cylinder corresponding to the inner side of the sample involves the height of the sample. This data is the sum of the initial height of the sample and the data measured by dial gauge 15.

[0032] In the third equation of quantity, the increase in the amount of airless water in the cylindrical space inside the upper stone ring 6 and the annular cap 14 involves the changes in the inner diameter of the upper stone ring 6 and the annular cap 14, as well as the height of the airless water level inside the sample. The inner diameters of the upper stone ring 6 and the annular cap 14 can be measured directly or obtained by consulting the product parameters. The change in the height of the airless water level inside the sample can be measured using component two.

[0033] Because of the waterproof membrane, the airless water on both the inside and outside of the sample will not be absorbed by the sample, thus ensuring the accuracy of the calculation results.

[0034] like Figure 2As shown, a groove is provided on the upper surface of the base 7. The groove is connected to channel 11 and channel 20. The outer diameter and inner diameter of the annular top cap 14, the permeable stone ring, and the base 7 are the same. The inner diameter of the base 7 refers to the inner diameter of the groove on its upper surface.

[0035] During the injection process, the airless water inside the sample first fills the groove and then reaches the upper end face of the lower stone ring 8. Therefore, by setting the groove, a certain amount of preparation time can be provided for the operator to adjust the water injection speed.

[0036] It should be noted that, as Figure 3 and Figure 4 As shown, the permeable stone ring is usually relatively thin. Since the inner and outer diameters of the upper stone ring 6 and the annular cap 14 are the same, when the liquid level floats up and down on the outside of the upper stone ring 6 and the annular cap 14 (below the outer port of channel 4 5), or when it floats up and down on the inside of the upper stone ring 6 and the annular cap 14, the cross-sectional area of ​​the height at which the liquid level is located remains unchanged, giving the liquid level a larger floating range and facilitating experimental operation.

[0037] As one possible example, in this embodiment, the waterproof membrane is a rubber membrane. Depending on the specific needs, those skilled in the art may also choose waterproof membranes made of other materials.

[0038] In some embodiments, the second conduit 2 is a transparent tube, and it has a lower scale 24 at the same height as the upper end face of the lower stone ring 8, and an upper scale 25 at the same height as the lower end face of the upper stone ring 6. During the experiment, the operator does not need to compare the liquid level in the second conduit 2 with the height of the upper end face of the lower stone ring 8, which is far away. Instead, the operator only needs to compare the liquid level in the second conduit 2 with the lower scale 24 and upper scale 25 drawn on the second conduit 2, thus avoiding errors caused by shifting lines of sight.

[0039] The inner diameters of conduit 1 and conduit 2 are the same, and they are arranged parallel to each other in the vertical direction. In the first equality relationship, the lengths corresponding to the increase in airless water content in conduit 1 and conduit 2 are involved. Since this increase in airless water content is at a vertical angle, its length is equal to the initial length of the sample. Conduit 1 and conduit 2 have the same diameter. According to the principle of communicating vessels, the increase in airless water content in conduit 1 is equal to the increase in airless water content in conduit 2; only one of them needs to be calculated. This arrangement simplifies the measurement process and reduces calculation steps.

[0040] like Figure 2 As shown, both channel 3 (10) and channel 4 (5) have multiple channels, which are symmetrically distributed along the circumference of the sample. By adopting a symmetrical distribution, the degassing water can quickly and uniformly penetrate into the sample during the saturation process.

[0041] The supply component is an airless water supply container 16; the suction unit includes an airless water collection container 12 equipped with a vacuum pump 13, and the airless water collection container 12 is connected to channel 4 5 via conduit 4 22. After the second end of conduit 3 21 extends into the carbon dioxide supply container or the airless water supply container 16, carbon dioxide or airless water is automatically drawn into conduit 3 21 under the negative pressure provided by the suction component. The first end of conduit 4 22 is connected to the second end of channel 4 5, the second end of conduit 4 22 is connected to the lower part of the airless water collection container 12, the upper part of the airless water collection container 12 is connected to the first end of conduit 5 23, and the second end of conduit 5 23 is connected to the vacuum pump 13.

[0042] When the vacuum pump 13 draws in deaerated water, the deaerated water collection container 12 serves as a temporary storage container. When the deaerated water collection container 12 is nearly full, the deaerated water inside needs to be emptied.

[0043] like Figure 2 As shown, the first measuring component includes: a float plate 18 floating on the outer side of the liquid surface of the sample and a corresponding laser displacement sensor 3; the second measuring component includes: a float plate 17 floating on the inner side of the liquid surface of the sample and a corresponding laser displacement sensor 19, and the annular top cap 14 is provided with a central hole for the laser to pass through; the height measuring unit is a dial gauge 15.

[0044] Laser displacement sensor 13 and laser displacement sensor 219 emit laser 1 and laser 2 downwards respectively. Laser 1 is reflected by float plate 18 and received by the receiving end of laser displacement sensor 13, while laser 2 is reflected by float plate 27 and received by the receiving end of laser displacement sensor 219.

[0045] Dial gauge 15, laser displacement sensor 1-3, and laser displacement sensor 2-19 are connected to the corresponding terminals via data cables for data acquisition. Before the test begins, the readings of dial gauge 15, laser displacement sensor 1-3, and laser displacement sensor 2-19 should be zeroed.

[0046] like Figure 2 As shown, it also includes a bracket 4, which is located on one side of the transparent container 9 and has a crossbeam suspended above the transparent container 9. The laser displacement sensor 1 3, the laser displacement sensor 2 19 and the dial gauge 15 are all fixed on the crossbeam of the bracket 4.

[0047] A method for dynamically measuring the dimensions of a hollow cylindrical sample, using the aforementioned device, includes the following steps: Measurement of the inner diameter of the sample before saturation: Inject de-aired water through conduit 1 until the liquid level in conduit 2 is level with the upper end of the lower stone ring 8; this process is called the first stage of water injection. Inject de-aired water through conduit 1 until the liquid level in conduit 2 is level with the lower end face of the upper stone ring 6; this process is called two-stage water injection. The water injection volume in the two-stage water injection is Q. The water volume in the portion of conduit 1 located between the upper stone ring 6 and the lower stone ring 8 is Q1. The water volume in the portion of conduit 2 located between the upper stone ring 6 and the lower stone ring 8 is Q2. The sample height before saturation is h0, the sample inner diameter before saturation is 2r0, and the thickness of the water-resistant membrane is m. First, Q, Q1, Q2, and h0 are obtained through measurement and calculation. Then, the equation Q - Q1 - Q2 = π(r0 - m) is applied. 2 h0, calculate 2r0; Measurement of sample height, inner diameter, and outer diameter during saturation process: Pour degassing water into the inside of the transparent container 9 until the liquid level is between the upper end face of the upper stone ring 6 and the outer port of the channel 4 5 of the annular top cap 14; pour degassing water into the inside of the sample until the liquid level is above the upper end face of the upper stone ring 6; ensure that the liquid level on both the inside and outside of the sample is always higher than the upper end face of the upper stone ring 6 in subsequent processes. The supply component provides carbon dioxide gas, and the suction component draws in the carbon dioxide gas; subsequently, the supply component provides degassed water, and the suction component draws in the degassed water; during this process, laser displacement sensor 13, laser displacement sensor 219, and dial gauge 15 measure Δh1, Δh2, and Δh3 respectively; the sample height during the saturation process is h. t The inner diameter of the sample is 2r t The outer diameter of the sample is 2R t The outer diameter of the sample before saturation is 2R0, the outer diameter of the annular cap 14, the permeable stone ring, and the base 7 is 2R1, the inner diameter of the annular cap 14, the permeable stone ring, and the base 7 is 2r1, the inner diameter of the transparent container 9 is 2r2, and the thickness of the water-resistant membrane is m; according to the equation: According to the second equality relationship: (πr2 2 -π(R1+m) 2 )△h1=π(R t +m) 2 (h0+△h3)-π(R0+m) 2 h0 Equality Relationship 3: π(r1-m) 2 △h2=π(r0-m) 2 h0-π(r t -m) 2 (h0+△h3) Equality Relationship Four: h t =h0+△h3 h was calculated t ,2r t and 2Rt .

[0048] Once the above data is obtained, further calculations can be performed to obtain the sample volume and porosity.

[0049] The above-disclosed embodiments are merely preferred embodiments of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A dynamic measurement device for the dimensions of a hollow cylindrical sample, characterized in that, include: The sample support assembly includes: a permeable stone ring, a base, an annular cap, and a water-resistant membrane. The permeable stone ring includes an upper stone ring and a lower stone ring that abut against both ends of the sample. The base abuts against the lower end face of the lower stone ring and has two channels communicating with the inside of the sample, and a third channel communicating with the lower stone ring. The annular cap abuts against the upper end face of the upper stone ring and has a fourth channel communicating with the upper stone ring at one end. The water-resistant membrane includes a first water-resistant membrane and a second water-resistant membrane. The two ends of the first water-resistant membrane are fixedly connected to the outside of the annular cap and the base, respectively, and the two ends of the second water-resistant membrane are fixedly connected to the inside of the annular cap and the base, respectively. The catheter assembly includes a first catheter connected to the other end of a first connecting channel and a second catheter connected to the other end of a second connecting channel, wherein the upper ends of both the first catheter and the second catheter are higher than the lower end face of the upper stone ring. The saturated medium assembly includes a supply assembly at the other end of the connecting channel three and a suction assembly at the other end of the connecting channel four; A transparent container for holding the sample carrier assembly and the sample; A height measuring unit is used to measure the axial displacement of the annular top cap; The liquid level measuring unit includes a first measuring component for measuring the height of the liquid level on the outer side of the sample, and a second measuring component for measuring the height of the liquid level on the inner side of the sample.

2. The device for dynamic measurement of the dimensions of a hollow cylindrical sample according to claim 1, characterized in that, The upper surface of the base has a groove, which is connected to channel one and channel two. The outer diameter and inner diameter of the annular top cap, the permeable stone ring, and the base are all the same. The inner diameter of the base refers to the inner diameter of the groove on its upper surface.

3. The device for dynamic measurement of the dimensions of a hollow cylindrical sample according to claim 1, characterized in that, The second conduit is a transparent tube, and it has a lower scale that is at the same height as the upper end face of the lower stone ring and an upper scale that is at the same height as the lower end face of the upper stone ring.

4. The device for dynamic measurement of the dimensions of a hollow cylindrical sample according to claim 1, characterized in that, The first and second catheters have the same inner diameter and are arranged parallel to each other in the vertical direction.

5. The device for dynamic measurement of the dimensions of a hollow cylindrical sample according to claim 1, characterized in that, Both Channel 3 and Channel 4 are provided in multiples and are symmetrically distributed along the circumference of the sample.

6. The device for dynamic measurement of the dimensions of a hollow cylindrical sample according to claim 1, characterized in that, The supply component is a degassing water supply container; the suction unit includes a degassing water collection container equipped with a vacuum pump, and the degassing water collection container is connected to the channel four via a conduit four.

7. The device for dynamic measurement of the dimensions of a hollow cylindrical sample according to claim 1, characterized in that, The first measuring component includes: a float plate floating on the outer surface of the liquid and a corresponding laser displacement sensor; the second measuring component includes: a float plate floating on the inner surface of the liquid and a corresponding laser displacement sensor, the annular top cap having a central hole for the laser to pass through; the height measuring unit is a dial indicator.

8. The device for dynamic measurement of the dimensions of a hollow cylindrical sample according to claim 7, characterized in that, It also includes a support frame located on one side of the transparent container and having a crossbeam suspended above the transparent container. The laser displacement sensor one, the laser displacement sensor two, and the dial indicator are all fixed to the crossbeam of the support frame.

9. A method for dynamic measurement of the dimensions of a hollow cylindrical sample, characterized in that, The measurement using the apparatus as described in any one of claims 1-8 includes the following steps: Measurement of the inner diameter of the sample before saturation: Inject de-aired water through conduit one until the liquid level in conduit two is level with the upper end of the lower stone ring; this process is called the first stage of water injection. Inject de-aired water through conduit one until the liquid level in conduit two is level with the lower end of the upper stone ring; this process is called two-stage water injection. The water injection volume in the two-stage water injection is Q. The water volume in the portion of conduit one located between the upper and lower stone rings is Q1, and the water volume in the portion of conduit two located between the upper and lower stone rings is Q2. The sample height before saturation is h0, the sample inner diameter before saturation is 2r0, and the thickness of the water-resistant membrane is m. Q, Q1, Q2, and h0 are first obtained through measurement and calculation, and then the equation Q - Q1 - Q2 = π(r0 - m) is applied. 2 h0, calculate 2r0; Measurement of sample height, inner diameter, and outer diameter during saturation process: Pour degassing water into the inside of the transparent container until the liquid level is between the upper end face of the upper stone ring and the outer port of channel four of the annular top cap; pour degassing water into the inside of the sample until the liquid level is above the upper end face of the upper stone ring; ensure that the liquid level on both the inside and outside of the sample is always higher than the upper end face of the upper stone ring in subsequent processes. The supply component provides carbon dioxide gas, and the suction component draws in the carbon dioxide gas; subsequently, the supply component provides degassed water, and the suction component draws in the degassed water; during this process, the height measurement unit and the liquid level measurement unit measure Δh1, Δh2, and Δh3 respectively; the sample height during the saturation process is h. t The inner diameter of the sample is 2r t The outer diameter of the sample is 2R t The outer diameter of the sample before saturation is 2R0, the outer diameter of the annular cap, permeable stone ring, and base is 2R1, the inner diameter of the annular cap, permeable stone ring, and base is 2r1, the inner diameter of the transparent container is 2r2, and the thickness of the water-resistant membrane is m; according to the equation: h t =h0+△h3; (πr2 2 -π(R1+m) 2 )△h1=π(R t +m) 2 (h0+△h3)-π(R0+m) 2 h0; π(r1-m) 2 △h2=π(r0-m) 2 h0-π(r t -m) 2 (h0+△h3); h was calculated t ,2r t and 2R t .

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