A test device and method for combined testing of solidified permeable pore pressure crushing of slag soil

Abstract

This invention discloses a device and method for co-testing the consolidation, permeability, pore pressure, and particle breakage characteristics of slag and soil. The device includes a loading frame with a servo loading system at its upper end. A consolidation cylinder is placed inside the loading frame, containing a sample with embedded pore water pressure sensors. Flexible isolation and support sampling modules are detachably connected to the bottom and side walls of the consolidation cylinder's inner wall. A pressure plate is located at the lower end of the servo loading system, with displacement gauges on both sides of the upper part of the pressure plate. A load sensor is positioned between the servo loading system and the pressure plate. Top and bottom drainage components are located at the top and bottom of the consolidation cylinder, respectively. Permeability testing modules are located on the upper and lower sides of the frame's outer wall, and a data acquisition system for collecting various monitoring data is located on the outer wall of the loading frame. This invention can determine compression consolidation deformation, pore water pressure, permeability, and particle breakage characteristics under the same loading path.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering testing equipment, and in particular to a device and method for testing the compression consolidation, permeability, pore water pressure, and particle breakage synergy of spoil heaps, soil-rock mixtures, and coarse-grained soil. Background Technology

[0002] Spoil and waste materials from spoil heaps typically originate from the construction processes of water conservancy and hydropower projects, transportation tunnel projects, mining excavation projects, and other earthwork projects. Influenced by factors such as engineering geological conditions, excavated soil and rock types, construction disturbance, filling methods, and weathering degrees, the material composition and particle size distribution of spoil and waste materials from different spoil heaps vary considerably. They can be categorized into various types, primarily consisting of soil particles, soft rock fragments, sand and gravel, crushed stone, boulders, or mixtures thereof. They are generally characterized by wide particle size distribution, strong heterogeneity, complex pore structure, significant compression deformation, marked changes in permeability, and sensitivity to particle breakage. During spoil heap filling, rainfall infiltration, groundwater action, and long-term self-weight consolidation, pore water pressure responses occur within the spoil and waste material. The formation, transmission, and dissipation of pore water pressure directly affect the consolidation settlement, seepage stability, slope deformation, and overall safety of the spoil and waste material.

[0003] Existing large-scale compression consolidation apparatuses are typically used to determine the compression deformation characteristics of coarse-grained soils or soil-rock mixtures under vertical loads, obtaining parameters such as load, axial displacement, compression coefficient, consolidation coefficient, resilient modulus, and related consolidation curves. However, ordinary large-scale compression consolidation apparatuses usually cannot simultaneously measure the permeability of the sample during the compression consolidation process, nor can they simultaneously obtain the pore water pressure at different heights within the sample and its dissipation law. For spoil heap soil, the pore structure continuously adjusts during loading and compaction, particle contact relationships change, and local fine particle migration and particle breakage further alter the seepage channels, leading to dynamic changes in permeability during the compression consolidation process. If the permeability coefficient is measured only before and after the test, it is difficult to reveal the coupling relationship between pore water pressure dissipation, permeability evolution, compression deformation, and particle breakage during the compression consolidation process.

[0004] Furthermore, after a traditional large-scale compression consolidation test, if particle breakage analysis is required, it is usually necessary to manually pry, excavate in layers, or pour out the sample. For samples such as spoil heap soil with wide particle size distribution, loose structure, and a mixture of coarse and fine particles, problems such as local collapse, prying impact, metal wall scraping, and fine particle loss can easily occur during unloading, mold opening, and transfer. This can result in additional particle breakage or fine powder loss, causing the particle size distribution, breakage rate, and fine material content analysis results after the test to deviate from the actual loading and breakage situation.

[0005] Therefore, it is necessary to improve the structure of the ordinary large-scale compression consolidation apparatus to form a collaborative testing device and method that can simultaneously acquire information on compression deformation, permeability, pore water pressure and particle breakage under the same loading path, so as to improve the accuracy and reliability of consolidation drainage, permeability evolution and particle breakage analysis of spoil heap soil. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for the coordinated testing of soil consolidation, permeability, pore pressure, and crushing, overcoming the problems in the prior art where ordinary large-scale compression consolidation instruments cannot simultaneously measure permeability, have insufficient pore water pressure monitoring layers, are difficult to obtain the pore pressure dissipation process, and are prone to additional particle breakage and fine particle loss during sample unloading.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A combined testing device for the consolidation, permeability, pore pressure, and crushing of slag and soil includes a loading frame. A servo loading system is installed at the upper end of the inner wall of the loading frame. A consolidation cylinder is installed inside the loading frame and coaxially with the servo loading system. A sample is placed inside the consolidation cylinder. Several pore water pressure sensors are embedded in layers along the height direction inside the sample. A flexible isolation and support sampling module for isolating the sample from the inner wall of the consolidation cylinder is detachably connected to the bottom and side walls of the inner wall of the consolidation cylinder. A pressure plate that cooperates with the consolidation cylinder is installed at the lower end of the servo loading system. A load sensor is installed between the servo loading system and the pressure plate. Displacement gauges are installed on both the left and right sides of the upper end of the pressure plate. The top and bottom of the consolidation cylinder are respectively provided with a top drainage component and a bottom drainage component. The bottom drainage component is fixedly connected to the lower end of the consolidation cylinder. The top drainage component is located at the lower end of the pressure plate and cooperates with the consolidation cylinder. The outer wall of the loading frame is provided with a permeability testing module that communicates with the corresponding top drainage component and bottom drainage component. The permeability testing module is used to control the water head difference between the upper and lower ends of the sample and measure the permeability of the sample under different vertical compression load stages. The outer wall of the loading frame is provided with a data acquisition system for collecting various monitoring data.

[0008] By adopting the above technical solution, through the cooperation of the loading frame, servo loading system, consolidation cylinder, top drainage component, bottom drainage component, pore water pressure sensor, permeability testing module, drainage volume measuring device, data acquisition system and flexible isolation support sampling module, it is possible to simultaneously measure compression consolidation deformation, pore water pressure, permeability and particle breakage characteristics under the same loading path, thus solving the problem that ordinary large compression consolidation instruments cannot simultaneously measure permeability and pore pressure dissipation process.

[0009] A further configuration of the present invention is that the permeability testing module includes a connecting hose, a ball valve, a head control device, a pressure gauge or a water level pipe, and a drainage volume measuring device, wherein the connecting hose is connected to the top drainage assembly and the bottom drainage assembly respectively.

[0010] By adopting the above technical solutions, the permeability evolution law at different compaction stages can be obtained. At the same time, pressure gauges or water level pipes can reflect the head loss during the seepage process in real time, providing a basis for analyzing changes in seepage paths and migration of fine particles.

[0011] A further feature of the present invention is that the permeability testing module can calculate the permeability coefficient of the sample under the corresponding compaction state by controlling the difference in water head between the upper and lower ends of the sample and measuring the amount of water drained per unit time after each level of vertical compression load has stabilized.

[0012] By adopting the above technical solution, the water head difference between the upper and lower ends of the sample can be controlled and the drainage volume can be measured under different compression loading stages, thereby obtaining the permeability coefficient under different compaction states and realizing dynamic testing of permeability changes with the compression consolidation process.

[0013] A further feature of the present invention is that a plurality of sealing lead holes are provided in layers along the height direction through the side wall of the consolidation cylinder, and the sealing lead holes of adjacent layers are staggered along the circumference of the consolidation cylinder. Each sealing lead hole is provided with a sealing sleeve, an O-ring, a compression joint or equivalent sealing structure, and an external signal interface in sequence on its inner wall and outer side. The output end of each pore water pressure sensor passes through the corresponding sealing lead hole through a flexible cable and is connected to an external data acquisition system through the external signal interface.

[0014] By adopting the above technical solution, the accuracy of pore water pressure sensor data transmission and the timeliness of response are ensured, and pore water leakage along the gap between the flexible cable and the pore wall is prevented. At the same time, by setting multiple pore water pressure sensors, the repeatability and reliability of pore pressure monitoring data are improved, and measurement errors are reduced.

[0015] A further configuration of the present invention is that the pore water pressure sensor is arranged at positions 0.15H, 0.50H, and 0.85H above the bottom of the sample, where H is the initial height of the sample.

[0016] By adopting the above technical solution and setting multiple layers of pore water pressure sensors on the side wall of the consolidation cylinder, the pore water pressure change process at different heights inside the sample can be obtained, which can reflect the vertical pore pressure gradient, the difference between the upper and lower boundaries and the pore pressure dissipation law.

[0017] A further feature of the present invention is that two pore water pressure sensors are provided at each height position, and the two pore water pressure sensors at the same height position are arranged symmetrically at 180° along the circumference of the consolidation cylinder.

[0018] By adopting the above technical solution, and by setting two circumferentially symmetrical pore water pressure measuring points at each height level, the uniformity of pore water pressure distribution in the horizontal direction can be determined, thereby improving the repeatability and reliability of pore pressure monitoring data.

[0019] A further feature of the present invention is that the inner diameter of the consolidation cylinder is 500 mm, the height of the sample is 300 mm, and the pore water pressure sensors are respectively embedded at positions 45 mm, 150 mm and 255 mm away from the bottom of the initial height of the sample.

[0020] By adopting the above technical solution, accurate monitoring of pore water pressure at key locations inside samples of typical sizes can be achieved.

[0021] A further configuration of the present invention is as follows: the flexible isolation support sampling module includes a support portion with an upper opening, a positioning ring disposed at the opening end of the support portion, a lifting connection portion disposed at the upper end of the positioning ring, and a plurality of reinforcing bands disposed on the outer wall of the support portion. The support portion is made of a flexible mesh material with a pore size of 0.05 to 0.20 mm, and the pore size is smaller than the minimum sieving particle size threshold in particle sieving analysis.

[0022] By adopting the above technical solution, the direct scraping between the sample and the metal wall can be reduced, thus reducing the influence of the wall effect on the particle crushing results. At the same time, after the particle crushing test is unloaded, the sample can be lifted and removed as a whole by the lifting connection, reducing the additional particle crushing caused by manual prying, impact and local collapse, improving the reliability of the particle size distribution and particle crushing rate analysis results after the test, and reducing the loss of fine particles during mold opening and transfer, thus improving the accuracy of fine material content and particle crushing analysis results.

[0023] This invention also provides a method for synergistic testing of the consolidation permeability pore pressure and crushing of slag soil, comprising the following steps: S1. Load the spoil soil sample into the consolidation cylinder, and during filling, embed pore water pressure sensors at positions 0.15H, 0.50H and 0.85H away from the bottom of the sample and connect them to the data acquisition system through flexible cables. At the same time, complete the sample leveling, sealing and saturation treatment. S2, connects the permeability test module, the drainage volume measurement device, and the data acquisition system; S3. Apply graded vertical compressive loads to the specimen according to the set loading path; S4. During the loading process, collect data on vertical load, axial displacement, pore water pressure, and drainage volume simultaneously. S5. After each loading stage stabilizes, the permeability test module controls the water head difference between the upper and lower ends of the sample to determine the permeability coefficient under the corresponding compaction state. S6. After unloading, take out the sample and lay a flexible isolation support sampling module at the bottom and inner wall of the consolidation cylinder. Then, put the spoil soil sample into the consolidation cylinder and carry out the particle crushing test of the sample under the same loading pressure. S7. The sample after the crushing test is taken out through the flexible isolation support sampling module, and the taken out sample is subjected to sieving test and particle crushing analysis. S8. Establish the correspondence between compression deformation, pore water pressure, permeability and particle breakage.

[0024] In summary, the present invention has the following beneficial effects: Firstly, this invention can simultaneously measure compression consolidation deformation, pore water pressure, permeability, and particle breakage characteristics under the same loading path, solving the problem that ordinary large-scale compression consolidation instruments cannot simultaneously measure permeability and pore pressure dissipation processes. Secondly, by embedding multiple layers of pore water pressure sensors distributed at equal intervals along the circumference inside the sample, this invention can obtain the pore water pressure change process at different height positions inside the sample, which can reflect the vertical pore pressure gradient, the difference between the upper and lower boundaries and the pore pressure dissipation law. At the same time, the three pore water pressure measuring points at equal intervals along the circumference can be used to determine the uniformity of pore water pressure distribution in the horizontal direction, thereby improving the repeatability and reliability of pore pressure monitoring data. Thirdly, the permeability testing module of the present invention can control the difference in water head between the upper and lower ends of the sample and measure the drainage volume under different compression load stages, thereby obtaining the permeability coefficient under different compaction states and realizing dynamic testing of permeability changes with the compression and consolidation process. Fourth, the present invention lays a flexible isolation support sampling module at the bottom and inner wall of the consolidation cylinder. During the particle crushing test, it can reduce the direct scraping between the sample and the metal wall surface, reduce the influence of the wall effect on the particle crushing results, and at the same time, the sample can be lifted out by the support part after unloading, reducing the additional particle crushing caused by manual prying, impact and local collapse, improving the reliability of the particle size distribution and particle crushing rate analysis results after the test, and reducing the loss of fine particles during mold opening and transfer, improving the accuracy of fine material content and particle crushing analysis results. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the experimental device of the present invention; Figure 2 This is a schematic diagram showing the installation location of the consolidation cylinder and pore water pressure sensor of the present invention; Figure 3 This is a diagram showing the location of the sealing lead hole of the present invention and the connection relationship between its inner wall and the rear end components; Figure 4 This is a schematic diagram of the connection of the permeability testing module of the present invention; Figure 5 This is a schematic diagram of the installation of the flexible isolation support sampling module inside the consolidation cylinder of the present invention; Figure 6 This is a schematic diagram of the sample particles being removed as a whole after the particle crushing test of the present invention, where a is the state diagram after unloading and b is the state diagram of the whole extraction. Figure 7 This is a flowchart of the collaborative testing method of the present invention.

[0026] In the diagram: 1. Loading frame; 11. Consolidation cylinder; 12. Sample; 2. Servo loading system; 21. Displacement gauge; 22. Load sensor; 3. Pressure plate; 4. Top drainage assembly; 5. Bottom drainage assembly; 6. Pore water pressure sensor; 61. Flexible cable; 62. Sealing lead hole; 63. Sealing sleeve; 64. O-ring; 65. Compression joint or equivalent sealing structure; 66. External signal interface; 7. Permeability testing module; 71. Connecting hose; 72. Ball valve; 73. Head control device; 74. Pressure gauge or water level pipe; 75. Discharge measurement device; 8. Flexible isolation support sampling module; 81. Support part; 82. Positioning ring; 83. Lifting connection part; 84. Reinforcing strip; 9. Data acquisition system. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to the accompanying drawings.

[0028] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] Example 1, such as Figure 1-3 As shown, a combined testing device for the consolidation, permeability, pore pressure, and crushing of slag and soil includes a loading frame 1 for providing reaction force support to the entire device. A servo loading system 2 is provided at the upper end of the inner wall of the loading frame 1. The servo loading system 2 can be loaded by a servo motor-driven screw, with a maximum axial load greater than or equal to 650 kN. It is suitable for compression consolidation tests of large coarse-grained soil or slag and soil in spoil heaps.

[0032] Within the loading frame 1, at the axial position of the servo loading system 2, is a consolidation cylinder 11 with openings at both the top and bottom, made of 304 stainless steel, and with an inner diameter of 500 mm. Inside the consolidation cylinder 11, a sample 12 with a height of 300 mm is placed. Inside the sample 12, along its height direction, nine pore water pressure sensors 6 with a range of 0–5 MPa are embedded in three layers. The three pore water pressure sensors 6 at the same height position are arranged at 120° intervals along the circumference of the consolidation cylinder 11. The nine pore water pressure sensors 6 are located at the bottom layer 45 mm from the bottom of the sample 12 and are used to monitor the pore water pressure response near the bottom drainage boundary; at the middle layer 150 mm from the bottom of the sample 12 and are used to monitor the peak pore water pressure in the main body area of ​​the sample 12 and its dissipation process; and at the upper layer 255 mm from the bottom of the sample 12 and are used to monitor the pore water pressure changes near the top loading end and the upper drainage boundary. By monitoring data from the three pore water pressure sensors 6 embedded in each of the three height layers, the vertical pore pressure gradient and pore pressure dissipation law inside the sample 12 can be obtained. By comparing the data from three equally spaced measuring points at the same height, the uniformity of the pore pressure distribution in the horizontal direction of the sample 12 can be determined.

[0033] The lower end of the servo loading system 2 is provided with a pressure plate 3 that cooperates with the consolidation cylinder 11 and is used to apply pressure to the sample 12 inside the consolidation cylinder 11. A load sensor 22 is provided between the servo loading system 2 and the pressure plate 3 to monitor the vertical load applied by the servo loading system 2 to the sample 12. Displacement gauges 21 are provided on both the left and right sides of the upper end of the pressure plate 3 to monitor the axial displacement of the pressure plate 3 relative to the upper end of the inner wall of the loading frame 1.

[0034] Nine sealing lead holes 62 are layered along the height direction of the side wall of the consolidation cylinder 11, and the three sealing lead holes 62 of adjacent layers are staggered at 40° along the circumference of the consolidation cylinder 11. Each sealing lead hole 62 has a sealing sleeve 63, an O-ring 64, a compression joint or equivalent sealing structure 65, and an external signal interface 66 arranged sequentially on the inner and outer walls. The output end of each pore water pressure sensor 6 passes through the corresponding sealing lead hole 62 through a flexible cable 61 and is connected to the data acquisition system 9 through the external signal interface 66.

[0035] The top and bottom of the consolidation cylinder 11 are respectively provided with a top drainage component 4 and a bottom drainage component 5. The bottom drainage component 5 is fixedly connected to the lower end of the consolidation cylinder 11. The top drainage component 4 is located at the lower end of the pressure plate 3 and cooperates with the inner wall of the consolidation cylinder 11. Both the top drainage component 4 and the bottom drainage component 5 include permeable stones, drainage boards, or porous drainage structures. The upper and lower ends of the outer wall of the loading frame 1 are respectively provided with permeability test modules 7 that communicate with the corresponding top drainage components 4 and bottom drainage components 5. The outer wall of the loading frame 1 is provided with a data acquisition system 9 that is connected to the servo loading system 2, load sensor, displacement gauge 21, pore water pressure sensor 6 and permeability test module 7 and is used to synchronously collect vertical load, axial displacement, pore water pressure, drainage volume, head difference and time data.

[0036] Example 2, as Figure 4 As shown, the permeability testing module 7 includes a connecting hose 71, a ball valve 72, a head control device 73, a pressure gauge or water level pipe 74, and a drainage volume measuring device 75. The connecting hose 71 is connected to the top drainage assembly 4 and the bottom drainage assembly 5 respectively. The ball valve 72 is installed on the connecting hose 71 to control water inlet, water outlet, or to close the drainage boundary. The head control device 73 is used to create a set head difference between the top and bottom of the sample 12. The pressure gauge or water level pipe 74 is used to display the head or pressure status during the test. The drainage volume measuring device 75 is used to record the permeation flow rate or drainage volume through the sample 12 per unit time.

[0037] During permeability testing, after a certain level of vertical load has been applied and stabilized, the corresponding ball valve 72 can be opened to allow water to flow through the top drainage assembly 4 into the sample 12 and out through the bottom drainage assembly 5. Alternatively, depending on the test requirements, the water can enter from the bottom and exit from the top. By controlling the head difference between the upper and lower ends of the sample 12 and recording the flow rate under steady-state seepage, the permeability coefficient of the sample 12 under this compaction state can be calculated using Darcy's law. When using a constant head permeation method, the permeability coefficient can be calculated using the following formula: K = QL / (AΔht) In the formula, k is the permeability coefficient, Q is the seepage flow rate in time t, L is the seepage path length of sample 12, A is the cross-sectional area of ​​sample 12, Δh is the head difference between the upper and lower ends, and t is the seepage time.

[0038] When using the variable head permeation method, the permeability coefficient can be calculated according to the variable head test formula. By repeating the permeation test at different loading stages, the law of permeability coefficient changing with vertical pressure, void ratio and particle breakage degree can be obtained.

[0039] Example 3, as Figure 5-6 As shown, the bottom and side walls of the inner wall of the consolidation cylinder 11 are detachably connected to a flexible isolation support sampling module 8 for isolating the sample 12 from the inner wall of the consolidation cylinder 11. The flexible isolation support sampling module 8 includes a support part 81 with an upper opening, a positioning ring 82 set at the opening end of the support part 81, a lifting connection part 83 set at the upper end of the positioning ring 82, and several reinforcing bands 84 set on the outer wall of the support part 81. The support part 81 is made of a flexible mesh material with a pore size of 0.10 mm, and the pore size is smaller than the minimum sieving particle size threshold of 0.25 mm in particle sieving analysis.

[0040] Before loading the sample, the support portion 81 is laid at the bottom of the consolidation cylinder 11 and then laid upwards along the inner side wall of the consolidation cylinder 11, so that the support portion 81 covers the area where the sample 12 is in direct contact with the metal inner wall of the consolidation cylinder 11. After loading, the sample 12 is located inside the support portion 81. During loading, the support portion 81 acts as a flexible isolation and support interface, which can reduce the direct scraping between coarse particles, gravel particles and the metal inner wall of the consolidation cylinder 11, and reduce additional breakage caused by wall friction and metal contact.

[0041] After the test is completed and unloaded, the entire sample 12 can be removed from the consolidation cylinder 11 via the lifting connection 83. This sampling method reduces local collapse, impact, and secondary breakage that occur during traditional prying, digging, or pouring out of the sample 12. Since the aperture of the support part 81 is smaller than the minimum sieve particle size threshold, it can effectively reduce the loss of fine particles during mold opening, transfer, and sample distribution, thereby improving the reliability of particle size distribution analysis and particle breakage rate calculation after the test.

[0042] Example 4, as Figure 7 As shown, a method for synergistic testing of the consolidation permeability pore pressure of slag and soil, implemented using the apparatus described in any one of claims 1 to 8, includes the following steps: S1. Prepare spoil heap soil samples 12 according to the particle size distribution, moisture content, dry density, or relative compaction designed for the experiment, and then fill the consolidation cylinder 11 in layers. During the filling process, simultaneously embed pore water pressure sensors 6 inside the samples 12 and connect them to the data acquisition system 9 via flexible cables 61. After each layer is filled, level and lightly compact the sample to ensure that the samples 12 reach the designed height and compaction state.

[0043] S2. Connect the permeability test module 7, the drainage volume measurement device 75, and the data acquisition system 9, and check each test module before the test to ensure that the initial readings of each sensor are stable.

[0044] S3. Perform graded compression consolidation loading according to the set loading path. The loading path can be selected according to the purpose of the test, such as 0.2 MPa, 0.4 MPa, 0.8 MPa, 1.6 MPa and 3.2 MPa, etc.

[0045] S4. After each load level is applied, the data acquisition system 9 synchronously records the data on the changes in vertical load, axial displacement, pore water pressure, and drainage volume over time.

[0046] S5. After each load level stabilizes or the pore water pressure dissipates to the set standard, the permeability coefficient under the corresponding compaction state is measured by controlling the head difference between the upper and lower ends of the sample 12 through the permeability test module 7. During the permeability test, the head difference, seepage flow rate, and time data are recorded, and it is determined whether the seepage has reached a steady state.

[0047] S6. After completing all loading and penetration tests, remove the vertical load, open the consolidation cylinder 11 and take out the sample 12. Then, lay the flexible isolation support sampling module 8 on the bottom and side walls of the inner wall of the consolidation cylinder 11, and check whether the flexible mesh isolation support layer is flat and continuous to avoid forming obvious wrinkles. Then, put the sample 12 into the consolidation cylinder 11 and conduct a particle breakage test under the same pressure load.

[0048] S7. After the particle breakage test is completed, the sample 12 is taken out as a whole by the flexible isolation support sampling module 8, and the taken-out sample 12 is sampled in layers, dried, sieved and particle size distribution analyzed, and the particle breakage rate, fine particle content change and related breakage index are calculated.

[0049] S8. Correlation analysis is performed on the compression deformation, pore water pressure, permeability coefficient and particle breakage index obtained at different loading stages to establish the coupling relationship between deformation, pore pressure, permeability and particle breakage, which is used to reveal the evolution of pore structure, pore pressure dissipation mechanism and permeability attenuation law of spoil heap soil during the compression consolidation process.

[0050] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make inventive modifications to this embodiment as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A test device for the combined testing of solidified soil permeability pore pressure and crushing, comprising a loading frame (1), characterized in that: A servo loading system (2) is provided at the upper end of the inner wall of the loading frame (1). A consolidation cylinder (11) is provided inside the loading frame (1) and coaxially arranged with the servo loading system (2). A sample (12) is placed inside the consolidation cylinder (11). Several pore water pressure sensors (6) are embedded in layers along the height direction inside the sample (12). A flexible isolation support sampling module (8) for isolating the sample (12) from the inner wall of the consolidation cylinder (11) is detachably connected to the bottom and side walls of the inner wall of the consolidation cylinder (11). A pressure plate (3) that cooperates with the consolidation cylinder (11) is provided at the lower end of the servo loading system (2). A load sensor (22) is provided between the servo loading system (2) and the pressure plate (3). Displacement gauges (21) are provided on both the left and right sides of the upper end of the pressure plate (3). The top and bottom of the consolidation cylinder (11) are respectively provided with a top drainage component (4) and a bottom drainage component (5). The bottom drainage component (5) is fixedly connected to the lower end of the consolidation cylinder (11). The top drainage component (4) is located at the lower end of the pressure plate (3) and cooperates with the consolidation cylinder (11). The outer wall of the loading frame (1) is provided with a permeability test module (7) that communicates with the corresponding top drainage component (4) and bottom drainage component (5). The permeability test module (7) is used to control the head difference between the upper and lower ends of the sample (12) and measure the permeability of the sample (12) under different vertical compression load stages. The outer wall of the loading frame (1) is provided with a data acquisition system (9) for collecting various monitoring data.

2. The synergistic testing device for the consolidation, permeability, and crushing of slag and soil according to claim 1, characterized in that: The permeability test module (7) includes a connecting hose (71), a ball valve (72), a head control device (73), a pressure gauge or water level pipe (74), and a drainage measurement device (75). The connecting hose (71) is connected to the top drainage assembly (4) and the bottom drainage assembly (5), respectively.

3. The synergistic testing device for the consolidation, permeability, and crushing of slag and soil according to claim 2, characterized in that: The permeability testing module (7) can calculate the permeability coefficient of the sample (12) under the corresponding compaction state by controlling the water head difference between the upper and lower ends of the sample (12) and measuring the drainage volume per unit time after each level of vertical compression load stabilizes.

4. The synergistic testing device for the consolidation, permeability, pore pressure, and crushing of slag and soil according to claim 1, characterized in that: A plurality of sealing lead holes (62) are provided in layers along the height direction through the side wall of the consolidation cylinder (11), and the sealing lead holes (62) of adjacent layers are staggered along the circumference of the consolidation cylinder (11). Each sealing lead hole (62) is provided with a sealing sleeve (63), an O-ring (64), a compression joint or equivalent sealing structure (65), and an external signal interface (66) in sequence on its inner wall and outer side. The output end of each pore water pressure sensor (6) passes through the corresponding sealing lead hole (62) through a flexible cable (61) and is connected to the data acquisition system (9) through the corresponding external signal interface (66).

5. The synergistic testing device for the consolidation, permeability, and crushing of slag and soil according to claim 4, characterized in that: The pore water pressure sensor (6) is embedded at positions 0.15H, 0.50H and 0.85H from the bottom of the initial height of the sample (12), where H is the initial height of the sample (12).

6. The slag consolidation permeability pore pressure crushing and co-testing device according to claim 5, characterized in that: Three pore water pressure sensors (6) are embedded at each height position, and the three pore water pressure sensors (6) at the same height position are arranged at equal intervals of 120° along the circumference of the consolidation cylinder (11).

7. The synergistic testing device for the consolidation, permeability, and pore pressure crushing of slag and soil according to claim 1, characterized in that: The inner diameter of the consolidation cylinder (11) is 500 mm, the height of the sample (12) is 300 mm, and the pore water pressure sensor (6) is embedded at heights of 45 mm, 150 mm and 255 mm from the bottom of the sample (12).

8. The synergistic testing device for the consolidation, permeability, and pore pressure crushing of slag and soil according to claim 1, characterized in that: The flexible isolation support sampling module (8) includes a support part (81) with an upper opening, a positioning ring (82) disposed at the opening end of the support part (81), a lifting connection part (83) disposed at the upper end of the positioning ring (82), and a number of reinforcing strips (84) disposed on the outer wall of the support part (81). The support part (81) is made of a flexible mesh material with a pore size of 0.05 to 0.20 mm, and the pore size is smaller than the minimum sieve particle size threshold in particle sieve analysis.

9. A method for synergistic testing of the consolidation permeability pore pressure and crushing of slag and soil, implemented using the apparatus described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1. The slag soil sample (12) of the spoil disposal site is put into the consolidation cylinder (11), and pore water pressure sensors (6) are buried at positions 0.15H, 0.50H and 0.85H away from the bottom of the sample (12) during filling. The sensors are connected to the data acquisition system (9) through a flexible cable (61). At the same time, the sample (12) is leveled, sealed and saturated. S2, connect the permeability test module (7), the drainage volume measurement device (75) and the data acquisition system (9); S3. Apply graded vertical compressive loads to the specimen (12) according to the set loading path; S4. During the loading process, collect data on vertical load, axial displacement, pore water pressure, and drainage volume simultaneously. S5. After each loading stage stabilizes, the permeability coefficient under the corresponding compaction state is measured by controlling the head difference between the upper and lower ends of the sample (12) through the permeability test module (7). S6. After unloading, take out the sample (12) and lay a flexible isolation support sampling module (8) at the bottom and inner wall of the consolidation cylinder (11). Then, put the slag soil sample (12) into the consolidation cylinder (11) and carry out the particle crushing test of the sample (12) under the same pressure load. S7. The sample (12) after the crushing test is taken out by the flexible isolation support sampling module (8), and the sample (12) is subjected to sieving test and particle crushing analysis. S8. Establish the correspondence between compression deformation, pore water pressure, permeability and particle breakage.

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