Method and device for testing indoor permeability of sample

Abstract

The invention discloses a sample indoor permeability test method and device, and belongs to the technical field of rock-soil layer characteristic tests.The test method is achieved based on the test device, the test device comprises a test box, a water permeable plate is arranged on the bottom side of the test box, and a containing space used for containing a sample block is formed above the water permeable plate; a water outlet cavity is formed above the containing space, and a first sealing ring is arranged on the upper surface of the water permeable plate. The pressure ring is arranged in the water outlet cavity and is of an annular structure; the lower end of the pressing ring is a conical section with the side face being a conical face. The sealing structure further comprises an annular second sealing ring, the second sealing ring is of an annular structure, a hole section at the upper end of the second sealing ring is a conical hole with the upper end diameter larger than the lower end diameter, and the hole wall of the conical hole is matched with the conical face. The adjusting device is used for changing the position of the compression ring in the height direction of the test box. The technical scheme can effectively improve the accuracy of a test result and has the characteristic of convenience in use.

Description

Technical Field

[0001] The invention relates to the technical field of rock and soil layer characteristic testing, and in particular to a sample indoor permeability testing method and device. Background Art

[0002] The seepage deformation test is a test to determine the critical slope (piping) at which fine particles are gradually lost with the seepage when seepage water passes through the rock and soil layer, and the destruction slope (soil flow) when the soil floats as a whole. The test samples are mostly coarse-grained soil samples. The test results are of great significance to the foundation construction of dam projects: the test results are used for the anti-seepage design in foundation construction, which can effectively ensure the stability and safety of hydraulic structures.

[0003] In the prior art, the permeability deformation parameters of the sample are mainly determined by indoor and outdoor tests and engineering experience. The instrument used in the indoor test is generally called a permeameter (permeability deformation test device), and its structure includes a test box, in which a permeable plate (generally a porous plate) is arranged. During the test, the sample is carried on the permeable plate, and an inlet pipe is arranged below the permeable plate. A water outlet pipe is arranged on the test box above the sample. The test process includes: after determining the direction of water flow on the sample, the sample is placed in the test box. To ensure the accuracy of the measurement result, after the sample is fully saturated with water, the water is gradually raised. The permeability test is carried out in the form of a water head. For example, the test phenomena under the water head are closely observed during the test. When the seepage rate reaches a stable level and there is no particle shedding of the sample, the test is considered to be completed under the water head of this level. The test is then raised to a higher head and tested until the sample is damaged by seepage after it is raised to a critical slope. During the test, the damage slope (such as the average of the slope when the seepage deformation phenomenon occurs and the slope of the previous test is taken as the damage slope), the maximum test slope (for example, the maximum test slope is produced under the test limit state under the highest water head and maximum flow of the test equipment), and the permeability coefficient are obtained.

[0004] For example, in the patent document with patent application number CN202210483582.8, an indoor soil sample permeability test device is provided. The specific principle is to analyze and study the permeability parameters of the soil sample by setting up containers, water supply devices, parameter measurement devices (such as water pressure sensors, flow meters) and parameter adjustment devices (such as counterweights, temperature control components), etc., to serve the construction design.

[0005] In order to make the sample permeability test results more scientifically serve the construction design, it is necessary to further study the sample permeability test technology. Summary of the invention

[0006] In order to further study the above-mentioned sample permeability test technology, the present invention provides a sample indoor permeability test method and device. This technical solution can effectively improve the accuracy of the test results and is easy to use.

[0007] The present invention provides a sample indoor permeability test device to solve the problem through the following technical points: a sample indoor permeability test device, comprising a test box, a water-permeable plate is arranged at the bottom side of the test box, a receiving space for receiving a sample block is formed above the water-permeable plate, a water outlet cavity is formed above the receiving space, a first sealing ring extending around the edge of the water-permeable plate is arranged on the upper surface of the water-permeable plate, and the first sealing ring is convex relative to the upper surface;

[0008] It also includes a pressure ring arranged in the water outlet cavity, the pressure ring is an annular structure extending along the inner wall of the test box, the outer circumference of the pressure ring is in contact with the inner wall of the test box, and can slide up and down relative to the test box;

[0009] The lower end of the pressure ring is a conical section with a conical surface on the side, the diameter of the upper end of the conical section is larger than the diameter of the lower end, the conical surface and the inner wall form an annular groove, and the cross-sectional shape of the annular groove is a triangle;

[0010] It also includes a second sealing ring in an annular shape, which is an annular structure extending along the inner wall of the test box, with the outer circumference in contact with the inner wall of the test box and capable of sliding up and down relative to the test box. The hole section at the upper end of the second sealing ring is a tapered hole with an upper end diameter greater than a lower end diameter, and the hole wall of the tapered hole fits with the tapered surface: after the tapered section is embedded in the tapered hole, the tapered surface fits with the hole wall surface;

[0011] The utility model also comprises an adjusting device for changing the position of the pressure ring in the height direction of the test box.

[0012] In the prior art, for the permeability test in the sample room, the commonly used test method for the sample block is: place the sample block on a water-permeable plate which is a porous plate, and fill water into the cavity below the water-permeable plate which serves as a water distribution cavity, exhaust air through the exhaust holes on the water distribution cavity at the beginning of water filling, and seal the exhaust holes after exhausting, and then, according to the required test water head, complete the permeability test under different levels of water head from low to high, and the monitoring and observation targets in the whole process include the threshing of the sample block, the seepage amount, and the seepage gradient, etc. However, due to the sample preparation accuracy of the sample block and the shedding of the side of the sample block before the permeability test, it is easy to form an uncontrollable seepage channel between the inner wall of the test box and the side of the sample block. The existence of the seepage channel affects the accuracy of the test results and even causes errors in the test results, so that the test results cannot scientifically guide the construction design. To address this problem, this solution provides a permeability test device that is conducive to the accuracy of the test results and is easy to use.

[0013] When this device is used in specific applications, the method of use is:

[0014] S1. Preparation before the test: After determining the water inlet and outlet surfaces of the sample block, an outer coating layer is used to cover the other surfaces of the sample block and the outer edges of the water inlet and outlet surfaces. The outer coating layer is a cement mortar layer;

[0015] S2, placing the sample block after the outer coating is cured in a test box, wherein the water inlet surface serves as the bottom surface of the sample block and is supported on the first sealing ring, and the supporting position of the first sealing ring on the sample block is located on the outer coating of the water inlet surface;

[0016] S3, placing a second sealing ring above the water outlet surface, the second sealing ring being supported on the outer coating layer of the water outlet surface;

[0017] S4, placing the pressure ring above the second sealing ring, and pressing the pressure ring downward through the adjusting device, so that the second sealing ring is deformed during the downward movement of the pressure ring and closes the gap between the inner wall of the test box and the sample block;

[0018] S5. The test steps are as follows: introducing test water into the sample block through the permeable plate; the test water enters the sample block through the middle area of ​​the outer coating on the water inlet surface; and then seeps out of the sample block from the middle area of ​​the outer coating on the water outlet surface; and completing the permeability test of the sample block under multiple different water heads.

[0019] Different from the prior art, this scheme forms an outer coating layer of cement mortar on the sample block, and the outer coating layer serves as a wrapping layer on the outside of the sample in the sample block. After the outer coating layer is cured, it plays a role in isolating water from penetrating and leaching from the position with the outer coating layer and serves as a hardened layer on the outside of the sample. In this way, after the first sealing ring is bonded to the outer coating layer on the water inlet surface and the second sealing ring is installed on the top of the sample block through a pressure ring, the first sealing ring and the second sealing ring serve as sealing structures on the upper and lower sides of the sample block, respectively, for preventing water from flowing between the side of the sample block and the inner wall of the test box. By avoiding the flow channel between the side of the sample block and the inner wall of the test box during the test, the purpose of facilitating the accuracy of the test results is achieved.

[0020] In addition, after solidification, the outer coating of the cement mortar layer forms a protective layer with good hardness and the ability to maintain shape integrity on the outer wall of the specimen block. The armoring effect of this protective layer on the specimen can effectively avoid and reduce the fragmentation or partial detachment caused by other external forces during the test, such as the force from the first sealing ring and the second sealing ring, thereby achieving the purpose of facilitating the accuracy of the test results.

[0021] In addition, the sealing ability of the first sealing ring is related to the test water head, the weight of the sample block, the surface weight of the sealing mating surface, etc. For the gap between the inner wall of the test box and the outer wall of the sample block, this scheme cooperates with the first sealing ring and the second sealing ring to form a sealing structure at the upper and lower ends of the gap respectively, and adopts a scheme in which the second sealing ring is equipped with a pressure ring and an adjustment device. In this way, not only the reliability of the sealing of the gap can be guaranteed, but also during the process of placing the sample block in the test box, the first sealing ring can be used to generate an elastic buffering effect to protect the sample block, so as to reduce the changes in the structural properties of the sample during the test. For the possible poor sealing of the first sealing ring, the second sealing ring is used to further strengthen the sealing condition to forcibly eliminate the flow channel formed through the gap. It is easy to understand that during the downward sliding of the pressure ring, the second sealing ring is pressurized, forcing the second sealing ring to strengthen its sealing ability on the upper end of the gap. In specific implementation, in order to facilitate the control of the pressure of the pressure ring on the second sealing ring, the test box is partially made of transparent plastic, and the transparent plastic is used to observe the liquid situation in the gap. For example, at the beginning of the test, by monitoring the rising speed of the water body in the gap, it is determined whether the pressure on the second sealing ring is sufficient, so as to avoid the occurrence of sample block fracturing accidents when the outer coating is thin.

[0022] In addition, with respect to the shape design of the pressure ring and the shape design of the second sealing ring, that is, a tapered section is formed at the lower end of the pressure ring, and a tapered hole is formed at the upper end of the second sealing ring. As the pressure ring moves downward, when the tapered section is embedded in the tapered hole and in the process of further pressing downward, the pressure of the tapered surface on the second sealing ring can better force the outer side surface of the second sealing ring to fit well with the inner wall of the test box, and at the same time can better force the second sealing ring to fit well with the outer coating on the top surface of the sample block. Experiments have shown that, compared with setting the pressure ring as a flat pressure plate and setting the second sealing ring as a flat pad, this structural form can enable the second sealing ring to have a good sealing effect when the sample block is subjected to smaller pressure.

[0023] In addition, the operation of the present scheme is different from that of the prior art only in that after obtaining the sample block and placing the sample block in the test box, the preparations before the permeability test can be completed by installing the second sealing ring and the pressure ring in sequence and pressing the pressure ring down by using the adjustment device. Therefore, the present scheme is not only simple in structure, but also easy to use, easy to obtain the flow channel that only passes through the sample, and the installation process has little interference with the internal structure of the sample.

[0024] In a specific embodiment, the first sealing ring and the second sealing ring are both rubber rings;

[0025] The first sealing ring is installed on the water-permeable plate through a groove provided on the edge of the upper surface of the water-permeable plate;

[0026] The cross-sectional shape of the second sealing ring in a natural state is a trapezoid, wherein the longer bottom side of the trapezoid is located on the outer side wall of the second sealing ring and is in contact with the inner wall of the test box, the shorter bottom side of the trapezoid is located on the inner side wall of the second sealing ring, one waist of the trapezoid is located on the hole wall of the tapered hole, and the other waist is perpendicular to the inner wall of the test box.

[0027] As an alternative, both the first sealing ring and the second sealing ring can use flexible packing rings, but flexible packing rings may introduce other substances into the water body to interfere with the test results, and the flexible buffering effect and sealing performance are not as good as rubber rings. The above groove is used to constrain the shape of the first sealing ring to avoid the failure of the first sealing ring due to the misalignment of the first sealing ring. The configuration of the above second sealing ring is: on the ring body structure of the second sealing ring, the bottom part is equal in width from top to bottom, and the upper part is narrower than the lower part. The outer side of the ring body structure is used to fit well with the inner wall of the test box, and the bottom surface of the ring body structure is supported on the outer coating layer of the water outlet surface. After the conical section fits with the conical hole, when the pressure ring is further pressed down, the pressure between the outer side of the ring body structure and the inner wall of the test box is forced to increase continuously, and the pressure between the bottom surface of the ring body structure and the outer coating layer is forced to increase continuously, so that the pressure ring forces the second sealing ring to achieve the required sealing performance at a smaller downward displacement. It is easy to understand that the longer bottom side is located on the outside of the ring structure, and the shorter bottom side is located on the inside of the ring structure, one waist is located on the hole wall of the tapered hole, and the other waist is located on the bottom surface of the ring structure.

[0028] In a specific embodiment, the test box includes an upper cover that is detachable relative to the test box, and the adjustment device includes a screw threadedly connected to the upper cover, the screw is threaded through the upper cover, the lower end of the screw is supported on the upper surface of the pressure ring, and the upper end of the screw is located above the upper cover;

[0029] There are multiple screw rods, and the screw rods are arranged in a spaced relationship with each other in the circumferential direction of the pressure ring.

[0030] In the above scheme, before placing the sample block in the test box, the upper cover is removed, and the test box is used as an open container to facilitate the installation of the sample block. After the sample block is installed, the upper cover is connected, and by rotating the screws, multiple screws are used to provide pressure to multiple positions of the pressure ring, thereby forcing the various positions of the pressure block to move downward evenly on the circumference, so that the second sealing ring produces the required deformation. This scheme provides a simple and easy-to-use adjustment device implementation method for the characteristic that the adjustment device can be reliably used throughout the entire cycle of the sample block after one adjustment.

[0031] In a specific embodiment, it also includes a first sensor and a second sensor disposed in the water outlet cavity, the first sensor is used to measure the turbidity of the water in the water outlet cavity, and the second sensor is used to measure the water content on the upper surface of the sample block;

[0032] The positions of the first sensor and the second sensor in the water outlet cavity can be adjusted up and down, and the second sensor can be adjusted to be in contact with the upper surface of the sample block.

[0033] In the above scheme, the purpose of the second sensor is: before the formal permeability test is carried out, first, water for infiltration is provided to the sample block through the water distribution chamber. The standard for complete infiltration is that the sample block is saturated with water. The specific method can use the following infiltration tube. The infiltration tube is connected to the water distribution chamber through the water inlet pipe. In this way, after the infiltration tube is erected and the second shut-off valve is opened, the water level in the infiltration tube is made equal to the top surface of the sample block by draining water from the water tank, and the liquid level of the sample block is maintained by replenishing water during the infiltration process. By observing the changes in the liquid level in the infiltration tube when no water is replenished, when it is determined that the sample block is saturated with water, the second shut-off valve is closed, and the permeability test of the sample block is carried out under step-by-step water head by gradually increasing the water head. In this way, the sample before the formal test is a saturated sample, which can make the subsequent test results more accurate. In this case, the second sensor is used to monitor the wetness of the upper end of the sample block. If the water content remains unchanged, it indicates that the sample block is saturated with water. Compared with manual observation, not only the result is accurate, but also automatic monitoring of saturated water absorption can be realized, thereby improving the efficiency of permeability tests on large quantities of sample blocks; the first sensor adopts a water turbidity detection sensor based on optical principles to replace manual work and monitor the particle situation in the water in the water outlet cavity. When there is no particle falling off the sample block, the monitoring judgment result is used as the basis for completing the permeability test under the current head level. Compared with manual observation, not only the result is accurate, but also automatic monitoring of no particle falling off can be realized when the seepage rate is stable (combined with a flow monitoring device), thereby improving the efficiency of permeability tests on large quantities of sample blocks and ensuring the reliability of the results.

[0034] In a specific embodiment, the test box includes an upper cover that is detachable relative to the test box, the first sensor is installed on the upper cover through an electric push rod, and the second sensor is installed on the upper cover through an elastic rod.

[0035] The purpose of setting up the above scheme is to adapt: ​​the elastic rod can elastically expand and contract so that the sample blocks of different heights can automatically maintain the second sensor in contact with the top surface of the sample block under the position compensation generated by the expansion and contraction of the elastic rod. The electric push rod is: the position of the first sensor is determined by the downward push amount of the first sensor by the electric push rod. For sample blocks of different heights, the first sensor can be kept close to the top surface of the sample block but not in contact with the sample block by setting an adaptive push amount, so as to achieve the purpose of protecting the first sensor and ensuring measurement sensitivity and accuracy.

[0036] In a specific embodiment, the test box has a water distribution cavity located below the water permeable plate, and also includes a water inlet pipe connected to the water distribution cavity;

[0037] The water inlet pipe is connected to a plurality of water supply pipes, each of which is equipped with a separate water tank, and each of which is connected to a first shutoff valve that controls the conduction state between the water supply pipe and the water inlet pipe.

[0038] The specific method of using the present solution is as follows: the water tank is fixed at different heights relative to the test box to provide test water of different water heads in the water distribution cavity through a water supply pipe and a water inlet pipe. For example, in a test process / stage where the water head increases step by step, each water tank is used in sequence from a low water tank to a high water tank, which is different from the prior art of continuously lifting water tanks. The water supply system has the characteristics of simple structure and easy use. For multiple test specimens in different water head test stages, water tanks of corresponding heights can be used for the tests in the corresponding stages. Therefore, these water tanks can serve multiple test specimens in different water head test stages at the same time. It is easy to understand that the water in the water distribution cavity passes through the hole on the permeable plate and enters the sample block from the bottom side of the sample block. Each first shut-off valve is used to control the conduction state between each water tank and the water distribution cavity. For example, after completing the low head test stage, open the first shut-off valve on the water supply pipe connected to the higher position water tank (the first shut-off valve on the water supply pipe used in the previous level needs to be closed to avoid waste of test water due to backflow and increase the difficulty of maintaining the liquid level position in the high position water tank, etc.) until all stages of the test are completed. In summary, this solution has a technical solution that simplifies the structure of the water supply system and enables the water supply system to serve different head test stages at the same time.

[0039] In a specific embodiment, a partition is provided on the test box, and the partition divides the internal space of the test box into a plurality of mutually isolated subspaces;

[0040] Each subspace is provided with a water-permeable plate and forms a containing space, a water outlet cavity and a water distribution cavity. Each water distribution cavity is equipped with an independent water inlet pipe, each water inlet pipe is equipped with a plurality of independent water supply pipes, and each water supply pipe is equipped with a first shut-off valve;

[0041] Each water inlet pipe is connected to the same number of water supply pipes, and the number of water tanks is equal to the number of water supply pipes on a single water inlet pipe;

[0042] Each water tank serves each water distribution cavity: for any water distribution cavity, each water tank is connected to the water distribution cavity pipeline through a water supply pipe.

[0043] The above scheme is: by dividing the test box into multiple subspaces, each subspace can independently carry out the permeability test of the sample block, and under the above water supply system scheme, the water supply system can simultaneously serve the sample blocks in different subspaces and in different water head test stages. Specifically, the partition separates the subspaces, and each subspace is equipped with a permeable plate, a containing space, a water outlet cavity and a water distribution cavity. Each water distribution cavity is equipped with a water inlet pipe, and each water inlet pipe is equipped with multiple water supply pipes, so that each subspace has the ability to conduct tests independently of other subspaces. For example, when several subspaces are in the same water head test stage, these subspaces are connected to the same water tank, and subspaces in different water pressure test stages are connected to different water tanks. For example, the number of water supply pipes on each water inlet pipe is N, and the number of water tanks is N, so that these subspaces can all be tested under N water head pressures.

[0044] In a specific embodiment, it also includes a pressure sensor and an infiltration tube connected to the water inlet pipe;

[0045] The pressure sensor is used to measure the water pressure in the water inlet pipe;

[0046] The infiltration tube is a hollow pipe connected to the water inlet pipe, the length of the infiltration tube is greater than or equal to the thickness of the sample block, one end of the infiltration tube is connected to the water inlet pipe, and the other end of the infiltration tube is connected to a second cut-off valve;

[0047] Also included is a liquid level monitoring device for monitoring the liquid level in the dip tube.

[0048] In this solution, the immersion tube is used to immerse the sample block before the test, and the pressure sensor is used to monitor the water pressure on the water inlet side of the sample block. The difference between the pressure sensor and the immersion tube is that the former automatically obtains the pressure detection result, and the latter can determine the water pressure through the position of the liquid level. For the immersion stage, due to the small water head, the immersion tube can accurately reflect the water head, and enable the immersion process to be performed under the specified water head to protect the sample block. For the water head used in the subsequent test, it is inconvenient to set the immersion tube longer or continuously lift the immersion tube, and the longer / higher immersion tube is not convenient to read the liquid level, so in the later test process, the pressure in the water inlet pipe can be obtained through the measurement value of the pressure sensor. The liquid level monitoring device is used to monitor the liquid level changes in the immersion tube, so as to output the result when the liquid level is lower than or higher than the set threshold, to prompt the replenishment and stop the replenishment, or automatically trigger the replenishment and stop the replenishment through linkage.

[0049] In a specific embodiment, the liquid level monitoring device includes a float, a magnet and a magnetron. The float is arranged in the immersion tube, the magnet is arranged in the float, and the magnetron is installed on the side wall of the immersion tube. The position of the magnetron in the height direction of the immersion tube is adjustable.

[0050] In view of the fact that the test sample blocks may have different heights, this solution provides a technical solution based on the principle of magnetically controlled switches. For a specific sample block height, after the magnetron is installed at an appropriate height, targeted infiltration head monitoring can be very conveniently provided after adjusting the magnetron installation height during infiltration.

[0051] The present solution also provides a method for testing indoor permeability of a sample, which uses the test device as described above to complete the indoor permeability test of a sample block, including a pre-test preparation step and a test step;

[0052] The pre-test preparation steps are: after determining the water inlet surface and the water outlet surface of the sample block, using an outer coating layer to cover the other surfaces of the sample block and the outer edges of the water inlet surface and the water outlet surface, wherein the outer coating layer is a cement mortar layer;

[0053] The sample block after the outer coating is cured is placed in a test box, the water inlet surface is used as the bottom surface of the sample block and is supported on the first sealing ring, and the supporting position of the first sealing ring on the sample block is located on the outer coating of the water inlet surface;

[0054] Placing a second sealing ring above the water outlet surface, the second sealing ring being supported on the outer coating layer of the water outlet surface;

[0055] The pressure ring is placed above the second sealing ring, and the pressure ring is pressed down by the adjusting device, so that the second sealing ring is deformed during the downward movement of the pressure ring and closes the gap between the inner wall of the test box and the sample block;

[0056] The test steps are to introduce test water into the sample block through the permeable plate, and complete the permeability test of the sample block under multiple different water heads.

[0057] The present invention has at least one of the following beneficial effects:

[0058] This solution can achieve the purpose of facilitating the accuracy of the test results by avoiding the presence of a flow channel between the side of the sample block and the inner wall of the test box during the test and reliably sealing the corresponding gap.

[0059] This solution can effectively avoid and reduce the fragmentation or partial shedding caused by other external forces during the test process by using the armoring effect of the outer coating layer on the specimen, which is beneficial to the accuracy of the test results.

[0060] The structural form provided by this solution can enable the second sealing ring to have a good sealing effect when the sample block is subjected to a smaller pressure, and from the perspective of maintaining the sample characteristics, it can achieve the purpose of facilitating the accuracy of the test results.

[0061] This solution is not only simple in structure, but also easy to use, easy to obtain a flow channel that only passes through the sample, and has little interference with the internal structure of the sample during the installation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 A cross-sectional view of a specific embodiment of the sample chamber permeability test device described in this scheme;

[0063] Figure 2 for Figure 1 A magnified view of part A;

[0064] Figure 3 for Figure 2 A magnified view of part B;

[0065] Figure 4 for Figure 3 The structure shown is a schematic diagram of the structure when the pressure ring is pressing down the second sealing ring;

[0066] Figure 5 This is a schematic diagram of the connection structure between the test box and the water supply system in a specific embodiment of the sample indoor permeability test device described in this scheme.

[0067] The reference numerals in the figure are respectively: 1, test box, 2, sample block, 3, outer coating layer, 4, permeable plate, 5, first sealing ring, 6, water distribution chamber, 7, water inlet pipe, 8, water outlet chamber, 9, first sensor, 10, electric push rod, 11, second sensor, 12, screw, 13, elastic rod, 14, pressure ring, 15, second sealing ring, 16, first shut-off valve, 17, infiltration pipe, 18, second shut-off valve, 19, water supply pipe, 20, water tank, 21, annular groove, 22, upper cover, 23, partition, 24, pressure sensor. DETAILED DESCRIPTION

[0068] The present invention is further described in detail below in conjunction with embodiments, but the present invention is not limited to the following embodiments:

[0069] Embodiment 1:

[0070] like Figure 1 and Figure 5 As shown, a permeability test device in a sample room comprises a test box 1, a water-permeable plate 4 is arranged at the bottom side of the test box 1, a receiving space for receiving a sample block 2 is formed above the water-permeable plate 4, a water outlet cavity 8 is formed above the receiving space, a first sealing ring 5 extending around the edge of the water-permeable plate 4 is arranged on the upper surface of the water-permeable plate 4, and the first sealing ring 5 is convex relative to the upper surface;

[0071] It also includes a pressure ring 14 disposed in the water outlet cavity 8, and the pressure ring 14 is an annular structure extending along the inner wall of the test box 1, with the outer circumference attached to the inner wall of the test box 1 and capable of sliding up and down relative to the test box 1;

[0072] The lower end of the pressure ring 14 is a conical section with a conical surface on the side. The diameter of the upper end of the conical section is larger than the diameter of the lower end. The conical surface and the inner wall form an annular groove 21. The cross-sectional shape of the annular groove 21 is a triangle.

[0073] It also includes a second sealing ring 15 in an annular shape. The second sealing ring 15 is an annular structure extending along the inner wall of the test box 1, with the outer circumference in contact with the inner wall of the test box 1 and capable of sliding up and down relative to the test box 1. The hole section at the upper end of the second sealing ring 15 is a tapered hole with a diameter at the upper end greater than that at the lower end. The hole wall of the tapered hole fits with the tapered surface. After the tapered section is embedded in the tapered hole, the tapered surface fits with the hole wall surface.

[0074] It also includes an adjusting device for changing the position of the pressure ring 14 in the height direction of the test box 1.

[0075] In the prior art, for the permeability test in the sample room, the commonly used test method for the sample block 2 is: place the sample block 2 on the water-permeable plate 4 which is a porous plate, and fill water into the cavity as the water distribution chamber 6 below the water-permeable plate 4, exhaust air through the exhaust hole on the water distribution chamber 6 at the beginning of water filling, and seal the exhaust hole after exhausting, and then, according to the required test water head, complete the permeability test under different levels of water head from low to high, and the monitoring and observation targets in the whole process include the threshing condition of the sample block 2, the seepage amount and the seepage gradient, etc. However, due to the limitation of the sample preparation accuracy of the sample block 2 and the falling condition of the side of the sample block 2 before the permeability test, it is easy to form an uncontrollable seepage channel between the inner wall of the test box 1 and the side of the sample block 2. The existence of the seepage channel affects the accuracy of the test results and even causes errors in the test results, so that the test results cannot scientifically guide the construction design. In view of this problem, this scheme provides a permeability test device that is conducive to the accuracy of the test results and is easy to use.

[0076] When this device is used in specific applications, the method of use is:

[0077] S1. Preparation before the test: After determining the water inlet surface and the water outlet surface of the sample block 2, an outer coating layer 3 is used to cover the other surfaces of the sample block 2 and the outer edges of the water inlet surface and the water outlet surface. The outer coating layer 3 is a cement mortar layer;

[0078] S2, placing the sample block 2 after the outer coating 3 is cured into the test box 1, the water inlet surface is used as the bottom surface of the sample block 2 and supported on the first sealing ring 5, and the supporting position of the first sealing ring 5 on the sample block 2 is located on the outer coating 3 of the water inlet surface;

[0079] S3, placing the second sealing ring 15 above the water outlet surface, the second sealing ring 15 is supported on the outer coating layer 3 of the water outlet surface;

[0080] S4, placing the pressing ring 14 above the second sealing ring 15, and pressing the pressing ring 14 downward by means of an adjusting device, so that the second sealing ring 15 is deformed during the downward movement of the pressing ring 14 and closes the gap between the inner wall of the test box 1 and the sample block 2;

[0081] S5. The test step is to introduce test water into the sample block 2 through the permeable plate 4. The test water enters the sample block 2 through the middle area of ​​the outer coating 3 on the water inlet surface, and then seeps out of the sample block 2 from the middle area of ​​the outer coating 3 on the water outlet surface, and completes the permeability test of the sample block 2 under multiple different water heads.

[0082] Different from the prior art, the present invention forms an outer coating layer 3 as a cement mortar layer on the specimen block 2, and uses the outer coating layer 3 as a wrapping layer on the outside of the specimen in the specimen block 2. After the outer coating layer 3 is cured, it plays a role in isolating water from penetrating and leaching from the position with the outer coating layer 3 and serves as a hardened layer on the outside of the specimen. In this way, after the first sealing ring 5 is bonded to the outer coating layer 3 on the water inlet surface and the second sealing ring 15 is installed above the specimen block 2 through the pressure ring 14, the first sealing ring 5 and the second sealing ring 15 serve as sealing structures on the upper and lower sides of the specimen block 2, respectively, for preventing water from flowing between the side of the specimen block 2 and the inner wall of the test box 1. By avoiding the flow channel between the side of the specimen block 2 and the inner wall of the test box 1 during the test, the purpose of facilitating the accuracy of the test results is achieved.

[0083] In addition, after solidification, the outer coating layer 3 of the cement mortar layer forms a protective layer with good hardness and the ability to maintain shape integrity on the outer wall of the specimen block 2. The armoring effect of the protective layer on the specimen can effectively avoid and reduce the fragmentation or partial detachment caused by other external forces during the test, such as the force from the first sealing ring 5 and the second sealing ring 15, thereby achieving the purpose of facilitating the accuracy of the test results.

[0084] In addition, the sealing ability of the first sealing ring 5 is related to the test water head, the weight of the sample block 2, the surface weight of the sealing mating surface, etc. For the gap between the inner wall of the test box 1 and the outer wall of the sample block 2, this solution forms a sealing structure at the upper and lower ends of the gap by cooperating with the first sealing ring 5 and the second sealing ring 15, and adopts a solution in which the second sealing ring 15 is equipped with a pressure ring 14 and an adjustment device. In this way, not only the reliability of the sealing of the gap can be guaranteed, but also during the process of placing the sample block 2 into the test box 1, the first sealing ring 5 can be used to generate an elastic buffer to protect the sample block 2, so as to reduce the changes in the structural properties of the sample during the test. For the possible poor sealing of the first sealing ring 5, the second sealing ring 15 is used to further strengthen the sealing condition to forcibly eliminate the flow channel formed through the gap. It is easy to understand that during the downward sliding of the pressure ring 14, the second sealing ring 15 is pressurized, forcing the second sealing ring 15 to strengthen its sealing ability on the upper end of the gap. In specific implementation, in order to facilitate the control of the pressure of the pressure ring 14 on the second sealing ring 15, the test box 1 is partially made of transparent plastic, and the transparent plastic is used to observe the liquid condition in the gap. For example, at the beginning of the test, by monitoring the rising speed of the water body in the gap, it is determined whether the pressure on the second sealing ring 15 is sufficient, so as to avoid the occurrence of sample block 2 fracturing accidents when the outer coating 3 is thin.

[0085] In addition, regarding the shape design of the pressure ring 14 and the shape design of the second sealing ring 15, that is, a tapered section is formed at the lower end of the pressure ring 14, and a tapered hole is formed at the upper end of the second sealing ring 15. As the pressure ring 14 moves downward, when the tapered section is embedded in the tapered hole and in the process of further pressing down, the pressure of the tapered surface on the second sealing ring 15 can better force the outer side surface of the second sealing ring 15 to fit well with the inner wall of the test box 1, and at the same time can better force the second sealing ring 15 to fit well with the outer coating 3 on the top surface of the sample block 2. It has been proved through experiments that, compared with setting the pressure ring 14 as a flat pressure plate and setting the second sealing ring 15 as a flat pad, this structural form can enable the second sealing ring 15 to have a good sealing effect when the sample block 2 is subjected to a smaller pressure.

[0086] In addition, the operation of the present scheme is different from that of the prior art only in that after obtaining the sample block 2 and placing the sample block 2 in the test box 1, the preparations before the permeability test can be completed by installing the second sealing ring 15 and the pressure ring 14 in sequence and pressing the pressure ring 14 downward using the adjustment device. Therefore, the present scheme is not only simple in structure, but also easy to use, easy to obtain the flow path that only passes through the sample, and the installation process has little interference with the internal structure of the sample.

[0087] More specifically, the first sealing ring 5 and the second sealing ring 15 are both rubber rings;

[0088] The first sealing ring 5 is installed on the water-permeable plate 4 through a groove provided at the edge of the upper surface of the water-permeable plate 4;

[0089] The cross-sectional shape of the second sealing ring 15 in the natural state is a trapezoid, wherein the longer bottom side of the trapezoid is located on the outer side wall of the second sealing ring 15 and is in contact with the inner wall of the test box 1, and the shorter bottom side of the trapezoid is located on the inner side wall of the second sealing ring 15, one waist of the trapezoid is located on the hole wall of the tapered hole, and the other waist is perpendicular to the inner wall of the test box 1.

[0090] As an alternative, both the first sealing ring 5 and the second sealing ring 15 can use flexible packing rings, but flexible packing rings may introduce other substances into the water body to interfere with the test results, and the flexible buffering effect and sealing performance are not as good as rubber rings. The above groove is used to constrain the shape of the first sealing ring 5 to avoid the failure of the first sealing ring 5 due to the misalignment of the first sealing ring 5. The configuration of the above second sealing ring 15 is: on the ring body structure of the second sealing ring 15, the bottom part is equal in width from top to bottom, and the upper part is narrower than the lower part. The outer side of the ring body structure is used to fit well with the inner wall of the test box 1, and the bottom surface of the ring body structure is supported on the outer coating 3 of the water outlet surface. After the conical section fits with the conical hole, when the pressure ring 14 is further pressed down, the pressure between the outer side of the ring body structure and the inner wall of the test box 1 is forced to increase continuously, and the pressure between the bottom surface of the ring body structure and the outer coating 3 is forced to increase continuously, so that the pressure ring 14 forces the second sealing ring 15 to achieve the required sealing performance at a small downward displacement. It is easy to understand that the longer bottom side is located on the outside of the ring structure, and the shorter bottom side is located on the inside of the ring structure, one waist is located on the hole wall of the tapered hole, and the other waist is located on the bottom surface of the ring structure.

[0091] More specifically, the test box 1 includes a detachable upper cover 22 relative to the test box 1, and the adjustment device includes a screw rod 12 threadedly connected to the upper cover 22, the screw rod 12 is connected to the upper cover 22, the lower end of the screw rod 12 is supported on the upper surface of the pressure ring 14, and the upper end of the screw rod 12 is located above the upper cover 22;

[0092] There are multiple screw rods 12 , and the screw rods 12 are arranged in a spaced relationship with each other in the circumferential direction of the pressure ring 14 .

[0093] In the above scheme, before placing the sample block 2 in the test box 1, the upper cover 22 is removed, and the test box 1 is used as an open container to facilitate the installation of the sample block 2. After the sample block 2 is installed, the upper cover 22 is connected, and by rotating the screw 12, multiple screws 12 are used to provide pressure to multiple positions of the pressure ring 14, thereby forcing each position of the pressure block to move downward uniformly on the circumference, so that the second sealing ring 15 produces the required deformation. This scheme provides a simple and easy-to-use adjustment device implementation method for the characteristic that the adjustment device can be reliably used throughout the entire cycle of the sample block 2 after one adjustment.

[0094] More specifically, it also includes a first sensor 9 and a second sensor 11 disposed in the water outlet cavity 8, wherein the first sensor 9 is used to measure the turbidity of the water in the water outlet cavity 8, and the second sensor 11 is used to measure the water content on the upper surface of the sample block 2;

[0095] The positions of the first sensor 9 and the second sensor 11 in the water outlet chamber 8 can be adjusted up and down, and the second sensor 11 can be adjusted to be in contact with the upper surface of the sample block 2 .

[0096] In the above scheme, the purpose of the second sensor 11 is: before the formal permeability test is carried out, first, water for infiltration is provided to the sample block 2 through the water distribution chamber 6. The standard for complete infiltration is that the sample block 2 is saturated with water. The specific method can use the following infiltration tube 17. The infiltration tube 17 is connected to the water distribution chamber 6 through the water inlet pipe 7. In this way, after the infiltration tube 17 is erected and the second shut-off valve 18 is opened, the water tank 20 is used to release water so that the water surface position in the infiltration tube 17 is the same height as the top surface of the sample block 2, and the liquid level of the sample block 2 is maintained by replenishing water during the infiltration process. By observing the liquid level changes in the infiltration tube 17 when no water is replenished, when it is determined that the sample block 2 is saturated with water, the second shut-off valve 18 is closed, and the permeability test of the sample block 2 is carried out under step-by-step water head by gradually increasing the water head. In this way, the sample before the formal test is a saturated sample, which can make the subsequent The test result is more accurate. In this case, the second sensor 11 is used to monitor the wetness of the upper end of the sample block 2. If the water content remains unchanged, it indicates that the sample block 2 is saturated with water. Compared with manual observation, not only the result is accurate, but also automatic monitoring of saturated water absorption can be realized, thereby improving the efficiency of permeability tests on large quantities of sample blocks 2; the first sensor 9 adopts a water turbidity detection sensor based on optical principles, which is used to replace manual work to monitor the particle situation in the water body in the water outlet cavity 8, so that when there is no particle falling off of the sample block 2, the monitoring and judgment result is used as the basis for completing the permeability test under the current head level. Compared with manual observation, not only the result is accurate, but also automatic monitoring of no particle falling off can be realized when the seepage rate is stable (combined with a flow monitoring device), thereby improving the efficiency of permeability tests on large quantities of sample blocks 2 and ensuring the reliability of the results.

[0097] More specifically, the test box 1 includes an upper cover 22 which is detachable relative to the test box 1 , the first sensor 9 is installed on the upper cover 22 via an electric push rod 10 , and the second sensor 11 is installed on the upper cover 22 via an elastic rod 13 .

[0098] The above scheme is set up for the purpose of adapting: the elastic rod 13 elastically expands and contracts, so that the sample blocks 2 of different heights can automatically maintain the second sensor 11 in contact with the top surface of the sample block 2 under the position compensation generated by the expansion and contraction of the elastic rod 13. The electric push rod 10 is: the position of the first sensor 9 is determined by the downward push amount of the first sensor 9 by the electric push rod 10. For sample blocks 2 of different heights, the first sensor 9 can be kept close to the top surface of the sample block 2 but not in contact with the sample block 2 by setting an adaptive push amount, so as to achieve the purpose of protecting the first sensor 9 and ensuring measurement sensitivity and accuracy.

[0099] More specifically, the test box 1 has a water distribution chamber 6 located below the water permeable plate 4, and also includes a water inlet pipe 7 connected to the water distribution chamber 6;

[0100] The water inlet pipe 7 is connected to a plurality of water supply pipes 19 , each of which is equipped with a separate water tank 20 , and each of which is connected to a first shutoff valve 16 for controlling the conduction state between the water supply pipe 19 and the water inlet pipe 7 .

[0101] The specific method of using the present solution is as follows: the water tank 20 is fixed at different heights relative to the test box 1, so as to provide test water of different water heads to the water distribution chamber 6 through the water supply pipe 19 and the water inlet pipe 7. For example, in a test process / stage where the water head increases step by step, each water tank 20 is used in sequence from the low water tank 20 to the high water tank 20, which is different from the prior art of continuously lifting the water tank 20. The water supply system has the characteristics of simple structure and easy use. For multiple test blocks 2 at different water head test stages, the corresponding stage of the test can use the water tank 20 of the corresponding height, so these water tanks 20 can serve multiple test blocks 2 at different water head test stages at the same time. It is easy to understand that the water in the water distribution chamber 6 passes through the hole on the permeable plate 4 and enters the sample block 2 from the bottom side of the sample block 2. Each first shut-off valve 16 is used to control the conduction state between each water tank 20 and the water distribution chamber 6. For example, after completing the low head test stage, open the first shut-off valve 16 on the water supply pipe 19 connected to the higher position water tank 20 (the first shut-off valve 16 on the water supply pipe 19 used in the previous level needs to be closed to avoid waste of test water due to backflow, increase the difficulty of maintaining the liquid level position in the high position water tank 20, etc.) until all stages of the test are completed. In summary, this solution has a technical solution that simplifies the structure of the water supply system and enables the water supply system to serve different head test stages at the same time.

[0102] More specifically, a partition 23 is provided on the test box 1, and the partition 23 divides the internal space of the test box 1 into a plurality of mutually isolated subspaces;

[0103] Each subspace is provided with a water-permeable plate 4 and forms a containing space, a water outlet cavity 8 and a water distribution cavity 6. Each water distribution cavity 6 is equipped with an independent water inlet pipe 7. Each water inlet pipe 7 is equipped with a plurality of independent water supply pipes 19. Each water supply pipe 19 is equipped with a first shut-off valve 16.

[0104] Each water inlet pipe 7 is connected to the same number of water supply pipes 19, and the number of water tanks 20 is equal to the number of water supply pipes 19 on a single water inlet pipe 7;

[0105] Each water tank 20 serves each water distribution cavity 6: for any water distribution cavity 6, each water tank 20 is connected to the water distribution cavity 6 pipeline through a water supply pipe 19.

[0106] The above scheme is a technical scheme that can realize the permeability test of the sample block 2 independently in each subspace by dividing the test box 1 into multiple subspaces, and under the above water supply system scheme, the water supply system can simultaneously serve the sample blocks 2 in different subspaces and in different water head test stages. Specifically, the partition 23 separates the subspaces, and each subspace is equipped with a water-permeable plate 4, a containing space, a water outlet cavity 8 and a water distribution cavity 6. Each water distribution cavity 6 is equipped with a water inlet pipe 7, and each water inlet pipe 7 is equipped with a plurality of water supply pipes 19, so that each subspace has the ability to conduct tests independently of other subspaces. For example, when several subspaces are in the same water head test stage, these subspaces are connected to the same water tank 20, and subspaces in different water pressure test stages are connected to different water tanks 20. For example, the number of water supply pipes 19 on each water inlet pipe 7 is N, and the number of water tanks 20 is N, so that these subspaces can all be tested under N water head pressures.

[0107] More specifically, it also includes a pressure sensor 24 and an infiltration tube 17 connected to the water inlet pipe 7;

[0108] The pressure sensor 24 is used to measure the water pressure in the water inlet pipe 7;

[0109] The infiltration tube 17 is a hollow pipe connected to the water inlet pipe 7. The length of the infiltration tube 17 is greater than or equal to the thickness of the sample block 2. One end of the infiltration tube 17 is connected to the water inlet pipe 7. The other end of the infiltration tube 17 is connected to a second shutoff valve 18.

[0110] It also includes a liquid level monitoring device for monitoring the liquid level in the infiltration tube 17.

[0111] In this solution, the infiltration tube 17 is used to infiltrate the sample block 2 before the test, and the pressure sensor 24 is used to monitor the water pressure on the water inlet side of the sample block 2. The difference between the pressure sensor 24 and the infiltration tube 17 is that the former automatically obtains the pressure detection result, and the latter can determine the water pressure through the position of the liquid surface. For the infiltration stage, due to the small water head, the infiltration tube 17 can accurately reflect the water head, and enable the infiltration process to be performed under the specified water head to protect the sample block 2. For the water head used in the subsequent test, it is inconvenient to set the infiltration tube 17 longer or continuously lift the infiltration tube 17, and the longer / higher infiltration tube 17 is not convenient to read the liquid level therein. Therefore, in the later test process, the pressure in the water inlet pipe 7 can be obtained through the measurement value of the pressure sensor 24. The liquid level monitoring device is used to monitor the change of the liquid level in the infiltration tube 17, so as to output the result when the liquid level is lower than or higher than the set threshold, so as to prompt the replenishment and stop the replenishment, or automatically trigger the replenishment and stop the replenishment through linkage.

[0112] More specifically, the liquid level monitoring device includes a float, a magnet and a magnetron. The float is arranged in the immersion tube 17, the magnet is arranged in the float, and the magnetron is installed on the side wall of the immersion tube 17. The position of the magnetron in the height direction of the immersion tube 17 is adjustable.

[0113] In view of the fact that the tested sample blocks 2 may have different heights, this solution provides a method based on the principle of magnetically controlled switches. For a specific height of the sample block 2, after the magnetron is installed at an appropriate height, a technical solution for targeted infiltration head monitoring can be provided very conveniently after adjusting the installation height of the magnetron during infiltration for the sample block 2 of a specific height.

[0114] This embodiment also relates to a method for testing indoor permeability of a sample, which uses the test device as described above to complete the indoor permeability test of the sample block 2, including a pre-test preparation step and a test step;

[0115] The pre-test preparation steps are: after determining the water inlet surface and the water outlet surface of the sample block 2, using an outer coating layer 3 to cover the other surfaces of the sample block 2 and the outer edges of the water inlet surface and the water outlet surface, wherein the outer coating layer 3 is a cement mortar layer;

[0116] The sample block 2 after the outer coating 3 is cured is placed in the test box 1, the water inlet surface is used as the bottom surface of the sample block 2 and supported on the first sealing ring 5, and the supporting position of the first sealing ring 5 on the sample block 2 is located on the outer coating 3 of the water inlet surface;

[0117] The second sealing ring 15 is placed above the water outlet surface, and the second sealing ring 15 is supported on the outer coating layer 3 of the water outlet surface;

[0118] The pressing ring 14 is placed above the second sealing ring 15, and the pressing ring 14 is pressed downward by the adjusting device, so that the second sealing ring 15 is deformed during the downward movement of the pressing ring 14 and closes the gap between the inner wall of the test box 1 and the sample block 2;

[0119] The test steps are to introduce test water into the sample block 2 through the water-permeable plate 4, and complete the permeability test of the sample block 2 under multiple different water heads.

[0120] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific embodiments of the present invention are limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, other embodiments obtained without departing from the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A permeability test device for a sample chamber, comprising a test chamber (1), wherein a water-permeable plate (4) is arranged on the bottom side of the test chamber (1), wherein a receiving space for receiving a sample block (2) is formed above the water-permeable plate (4), and a water outlet cavity (4) is formed above the receiving space, wherein: A first sealing ring (5) is provided on the upper surface of the water-permeable plate (4) and extends around the edge of the water-permeable plate (4), and the first sealing ring (5) is convex relative to the upper surface; It also includes a pressure ring (14) arranged in the water outlet cavity (4), wherein the pressure ring (14) is an annular structure extending along the inner wall of the test box (1), with the outer circumference in contact with the inner wall of the test box (1) and capable of sliding up and down relative to the test box (1); The lower end of the pressure ring (14) is a conical section with a conical surface on the side, the upper end diameter of the conical section is larger than the lower end diameter, the conical surface and the inner wall form an annular groove (21), and the cross-sectional shape of the annular groove (21) is a triangle; It also comprises a second sealing ring (15) in an annular shape. The second sealing ring (15) is an annular structure extending along the inner wall of the test box (1), with the outer circumference in contact with the inner wall of the test box (1) and capable of sliding up and down relative to the test box (1). The hole section at the upper end of the second sealing ring (15) is a conical hole with a diameter at the upper end greater than a diameter at the lower end. The hole wall of the conical hole matches the conical surface. After the conical section is embedded in the conical hole, the conical surface matches the hole wall surface. It also includes an adjustment device for changing the position of the pressure ring (14) in the height direction of the test box (1).

2. A sample room permeability test device according to claim 1, characterized in that: The first sealing ring (5) and the second sealing ring (15) are both rubber rings; The first sealing ring (5) is installed on the water-permeable plate (4) via a groove provided at an edge position of the upper surface of the water-permeable plate (4); The cross-sectional shape of the second sealing ring (15) in its natural state is a trapezoid, wherein the longer bottom side of the trapezoid is located on the outer side wall of the second sealing ring (15) and is in contact with the inner wall of the test box (1), and the shorter bottom side of the trapezoid is located on the inner side wall of the second sealing ring (15), one waist of the trapezoid is located on the hole wall of the tapered hole, and the other waist is perpendicular to the inner wall of the test box (1).

3. A sample room permeability test device according to claim 1, characterized in that: The test box (1) comprises an upper cover (22) which is detachable relative to the test box (1), and the adjustment device comprises a screw rod (12) which is threadedly connected to the upper cover (22), the screw rod (12) is threadedly connected to the upper cover (22), the lower end of the screw rod (12) is supported on the upper surface of the pressure ring (14), and the upper end of the screw rod (12) is located above the upper cover (22); There are a plurality of screw rods (12), and the screw rods (12) are arranged in a spaced relationship from each other in the circumferential direction of the pressure ring (14).

4. A sample room permeability test device according to claim 1, characterized in that: It also includes a first sensor (9) and a second sensor (11) arranged in the water outlet chamber (8), the first sensor (9) being used to measure the turbidity of the water in the water outlet chamber (8), and the second sensor (11) being used to measure the water content on the upper surface of the sample block (2); The positions of the first sensor (9) and the second sensor (11) in the water outlet chamber (8) can be adjusted up and down, and the second sensor (11) can be adjusted to be in contact with the upper surface of the sample block (2).

5. A sample room permeability test device according to claim 4, characterized in that: The test box (1) comprises an upper cover (22) which is detachable relative to the test box (1); a first sensor (9) is mounted on the upper cover (22) via an electric push rod (10); and a second sensor (11) is mounted on the upper cover (22) via an elastic rod (13).

6. The permeability test device for a sample chamber according to claim 1, characterized in that: The test box (1) comprises a water distribution chamber (6) located below the water permeable plate (4), and also comprises a water inlet pipe (7) connected to the water distribution chamber (6); The water inlet pipe (7) is connected to a plurality of water supply pipes (19), each water supply pipe (19) is equipped with a separate water tank (20), and each water supply pipe (19) is connected to a first shutoff valve (16) for controlling the conduction state between the water supply pipe (19) and the water inlet pipe (7).

7. A sample room permeability test device according to claim 6, characterized in that: The test box (1) is provided with a partition (23), and the partition (23) divides the internal space of the test box (1) into a plurality of mutually isolated subspaces; Each subspace is provided with a water-permeable plate (4) and forms a containing space, a water outlet cavity (4) and a water distribution cavity (6); each water distribution cavity (6) is equipped with an independent water inlet pipe (7); each water inlet pipe (7) is equipped with a plurality of independent water supply pipes (19); each water supply pipe (19) is equipped with a first shut-off valve (16); Each water inlet pipe (7) is connected to the same number of water supply pipes (19), and the number of water tanks (20) is equal to the number of water supply pipes (19) on a single water inlet pipe (7); Each water tank (20) serves each water distribution chamber (6): for any water distribution chamber (6), each water tank (20) is connected to the water distribution chamber (6) pipeline via a water supply pipe (19).

8. A sample room permeability test device according to claim 6 or 7, characterized in that: It also includes a pressure sensor (24) and an infiltration tube (17) connected to the water inlet pipe (7); The pressure sensor (24) is used to measure the water pressure in the water inlet pipe (7); The infiltration tube (17) is a hollow pipe connected to the water inlet pipe (7). The length of the infiltration tube (17) is greater than or equal to the thickness of the sample block (2). One end of the infiltration tube (17) is connected to the water inlet pipe (7). The other end of the infiltration tube (17) is connected to a second shut-off valve (18). It also includes a liquid level monitoring device for monitoring the liquid level in the infiltration tube (17).

9. A sample chamber permeability test device according to claim 8, characterized in that: The liquid level monitoring device comprises a float, a magnet and a magnetron, wherein the float is arranged in an immersion tube (17), the magnet is arranged in the float, and the magnetron is installed on the side wall of the immersion tube (17), and the position of the magnetron in the height direction of the immersion tube (17) is adjustable.

10. A method for testing permeability of a sample chamber, characterized in that: The method uses the test device described in any one of claims 1 to 9 to complete the indoor permeability test of the sample block (2), including a pre-test preparation step and a test step; The pre-test preparation steps are as follows: after determining the water inlet surface and the water outlet surface of the sample block (2), using an outer coating layer (3) to cover the other surfaces of the sample block (2) and the outer edges of the water inlet surface and the water outlet surface, wherein the outer coating layer (3) is a cement mortar layer; The sample block (2) after the outer coating layer (3) is cured is placed in a test box (1), the water inlet surface serves as the bottom surface of the sample block (2) and is supported on a first sealing ring (5), and the supporting position of the first sealing ring (5) on the sample block (2) is located on the outer coating layer (3) of the water inlet surface; Placing a second sealing ring (15) above the water outlet surface, wherein the second sealing ring (15) is supported on the outer coating layer (3) of the water outlet surface; The pressure ring (14) is placed above the second sealing ring (15), and the pressure ring (14) is pressed downward by an adjusting device, so that the second sealing ring (15) is deformed during the downward movement of the pressure ring (14) and closes the gap between the inner wall of the test box (1) and the sample block (2); The test steps are to introduce test water into the sample block (2) through the water-permeable plate (4), and to complete the permeability test of the sample block (2) under a plurality of different water heads.

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