Method and device for testing characteristics of core sample after rock mass grouting

Abstract

The invention discloses a core sample characteristic test method and device after rock mass grouting, and belongs to the technical field of geologic structure tests.The device comprises a device box, and a second water permeable plate and a partition plate are arranged in the device box; the space in the device box is divided into a first space, a second space and a third space which are sequentially arranged from top to bottom by the second permeable plate and the partition plate; the device further comprises a lifting pump and a discharge pipeline. The device further comprises a pressing mechanism installed at the top of the first space, the pressing mechanism is provided with a pressing rod facing the second permeable plate, and an elastic piece and a pressure sensor are installed on the pressing rod. According to the scheme, the core sample can be prevented from being transferred in the dry-wet cycle durability test, the test convenience is improved, core sample surface stripping caused by transferring is avoided, and the accuracy of a test result is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of geological structure testing, and in particular to a method and a device for testing the characteristics of a core sample after grouting a rock mass. Background Art

[0002] Grouting is often used to treat faults and broken zones in dam foundations. Chemical grouting materials are an important grouting material, which are widely used in foundation treatment of water conservancy projects and reinforcement of concrete cracks. The mainstream chemical grouting materials in infrastructure construction include epoxy resin grouting materials, foamed polyurethane grouting materials and acrylate grouting materials. There are many epoxy resin grouting materials on the market with adjustable viscosity, good performance, and can be constructed and used in low temperature and water environments. In the practice of water conservancy and hydropower engineering, construction design units can select chemical grouting materials suitable for the current water conservancy and hydropower engineering anti-seepage reinforcement from mainstream brands based on the experience of using various epoxy resin grouting materials and the characteristics of the poor geological system of the project. Before formal on-site use, analyze its own material properties and the performance of the samples obtained after grouting, so as to further select the slurry model and component ratio suitable for current use, and guide the formation of grouting construction technology.

[0003] The study of the characteristics of chemical grouting materials includes the durability characteristics of the core sample after grouting, among which an important content of the experimental study is the durability of the dry-wet cycle. The specific operation method of the dry-wet cycle durability test is: after obtaining the rock mass in the broken zone, carry out an indoor grouting simulation test; after grouting and completing the curing, obtain the core sample by drilling and coring; measure the initial length, mass, dynamic elastic modulus and other reference values ​​of the core sample, and after N swelling cycles, measure the length, mass, and dynamic elastic modulus again to obtain the change value, and calculate the test results after N swelling cycles based on the reference value and the change value. For example, the shrinkage (swelling) rate of the specimen after N shrinkage and swelling cycles is: the ratio of the difference between the length of the specimen and the reference length after N shrinkage and swelling cycles to the reference length. Among them, the swelling cycle is: after the core sample is subjected to shrinkage treatment in an environment with controlled temperature and humidity (generally constant temperature and humidity), it is immersed in a calcium hydroxide solution tank for swelling treatment, and the shrinkage treatment and swelling treatment are alternated until the number of test results is reached.

[0004] The time required for the existing single shrinkage treatment and swelling treatment is relatively long (usually 24 hours, that is, the test cycle for completing one shrinkage treatment and one swelling treatment is 48 hours), and multiple cycles are required (for example, a measurement is performed after 10 cycles, and the total number of cycles is usually 150 times). The current manual processing method has high labor input, and core sample transfer occurs in each test cycle, which makes the operation cumbersome. Based on the operational characteristics of the existing dry-wet cycle durability, in order to improve the convenience of the core sample dry-wet cycle durability test and the accuracy of the results, it is necessary to further optimize the relevant technologies. Summary of the invention

[0005] In response to the above-mentioned problem of optimizing the core sample dry-wet cycle durability test technology, the present invention provides a method and device for testing the characteristics of core samples after rock grouting. This scheme can avoid the transfer of core samples during the dry-wet cycle durability test, improve the convenience of the test and avoid surface peeling of the core samples caused by the transfer, which is beneficial to the accuracy of the test results.

[0006] The core sample characteristic test device after grouting of a rock mass provided by the present invention solves the problem through the following technical points: the core sample characteristic test device after grouting of a rock mass comprises a device box, wherein a second water-permeable plate and a partition are arranged in the device box, and the second water-permeable plate and the partition divide the space in the device box into a first space, a second space and a third space arranged in sequence from top to bottom, the second water-permeable plate is located above the partition, the first space and the second space are connected through the conducting hole on the second water-permeable plate, and the partition divides the second space and the third space into mutually isolated spaces;

[0007] Also included is a lift pump for injecting the medium in the third space into the second space;

[0008] Also included is a discharge pipeline for discharging the medium in the second space to the third space;

[0009] It also includes a clamping mechanism installed on the top of the first space, the clamping mechanism has a clamping rod facing the second water-permeable plate, and an elastic member and a pressure sensor are installed on the clamping rod. The elastic member is used to achieve: when the clamping rod provides a clamping force to the core sample below it, the clamping force is transmitted through the elastic member, and the pressure sensor is used to measure the magnitude of the clamping force.

[0010] In the above scheme, the first space is used as a space for shrinkage treatment of the core sample, specifically, the core sample is supported on the second permeable board, and the internal environment of the first space is maintained as a gas phase environment for shrinkage treatment. The environmental control parameters include temperature parameters and humidity parameters. Since the temperature and humidity of the environment in the control box are conventional technical means, the relevant control means are not mentioned in the above scheme. One implementation method is to provide a gas phase circulation device for the first space, and the gas phase circulation device is connected in series with a temperature control device and a humidity control device. The gas temperature and humidity in the first space are processed by the gas phase circulation device, so that the shrinkage treatment has the set gas phase environmental conditions. Similarly, for swelling treatment, it is generally required that the liquid medium (such as saturated calcium hydroxide solution) used for swelling treatment also has the same temperature as the gas temperature in the first space. Those skilled in the art can design the shrinkage treatment method without inventiveness. In the case of labor, the liquid medium contained in the third space can also be treated to have the required temperature, and the first space is also used as a space for core sample swelling treatment. Specifically, the liquid medium stored in the third space is lifted to the second space by a lifting pump, and the liquid medium further enters the first space through the conducting hole on the second permeable plate. When the first space has a liquid level that can immerse the core sample, the liquid medium injection is stopped, and the liquid level in the first space is maintained for a set time to perform swelling treatment. After the swelling treatment is completed, the liquid medium is refluxed through the discharge pipeline to restore the first space to a state for shrinkage treatment. Completing one shrinkage treatment and one swelling treatment is one dry-wet cycle. After repeating a set number of dry-wet cycles, the change value of the characteristic parameter of the core sample relative to the baseline parameter before treatment is obtained. By comparing with the baseline parameter, test data such as shrinkage rate and swelling rate can be obtained.

[0011] Related to the above, the present invention also relates to a method for testing the properties of core samples after grouting of rock mass, the method using the test device as described above to conduct a durability property test on the grouting core sample, comprising the following steps:

[0012] S1, placing the test core sample in the first space and supporting it on the second water-permeable plate, and completing the shrinkage treatment of the core sample for a set time by controlling the temperature and humidity of the gas phase environment in the first space;

[0013] S2, injecting a liquid medium for swelling treatment into the second space through a lifting pump, and injecting the liquid medium into the first space through the conducting hole on the second water-permeable plate, and forming a liquid level of a set height in the first space, completing swelling treatment of the core sample for a set time;

[0014] S3, after the wet expansion treatment is completed, the liquid medium in the first space and the second space is discharged into the third space through the discharge pipeline, the gas phase environment in the first space is restored to the environmental conditions required for the shrinkage treatment, and steps S1 and S2 are repeated to perform a set number of dry-wet cycle treatments on the core sample;

[0015] In the process of injecting the liquid medium into the first space, a clamping mechanism is used to provide a continuous clamping force on the top of the core sample. The clamping force is transmitted through an elastic member, and the clamping force is controlled to a set size through the feedback value of the pressure sensor. After the liquid medium is injected into the first space, the force of the clamping mechanism on the top of the core sample is removed, and the pressure sensor is lifted above the liquid level of the liquid medium by the clamping mechanism.

[0016] Compared with the prior art, this solution integrates the shrinkage treatment and swelling treatment of the core sample in the first space, and realizes the environmental switching in the first space through a lifting pump and a discharge pipeline. Compared with the prior art in which the switching between the shrinkage treatment and the swelling treatment involves the transfer of the core sample between different containers, this solution can avoid the local micro-peeling of the core sample surface caused by the transfer, which is beneficial to the accuracy of the test results of mass loss in the dry-wet cycle durability; at the same time, since it does not involve related transfers, it can effectively improve the convenience of the test; at the same time, the transfer of the liquid medium between the first space and the third space, the time control of the storage of the liquid medium in the first space, etc. can be completed through common control modules and actuators. For hundreds of dry-wet cycles of the core sample, this solution provides a simple structural basis for realizing automatic control based on the control module and the actuator, which can effectively reduce the manpower input required for the core sample characteristic test after grouting and ensure that the characteristic test is completed under standardized operation.

[0017] At the same time, in this scheme, a second permeable plate and a partition are used to divide the space of the device box. The partition plays the function of maintaining the liquid environment in the first space during the wet expansion treatment, and the partition plays the function of isolating the gas phase environment and the liquid phase environment during the shrinkage treatment, so as to maintain the environmental parameters in the first space during the shrinkage treatment. The second permeable plate serves as a water distribution plate when liquid enters the first space, which can effectively reduce the possibility of the first space being washed away, displaced and tipped over when liquid enters; the clamping mechanism maintains the position stability and anti-lodging ability of the core sample under the liquid inflow condition, and after a set number of dry-wet cycle treatments, in conjunction with the pressure sensor, under the set clamping force on the core sample, it can not only protect the core sample and prevent the core sample from being damaged under the clamping force, but also The sample baseline length measurement and the length measurement after completing the dry-wet cycle treatment, when the pressure sensor has the same measurement value, and the measurement value is the set size, the length of the core sample at different stages and the length change that occurs can be accurately obtained by measuring the displacement of the clamping rod. Therefore, the accurate length value required for the calculation of the shrinkage (wet expansion) rate can be obtained through this scheme; the clamping rod with elastic parts can provide flexible compression for the core sample, which can effectively avoid the core sample being subjected to excessive compression force when being compressed due to the low control accuracy of the clamping rod displacement, resulting in surface peeling due to compression, resulting in inaccurate subsequent quality measurement results, or inaccurate subsequent length and dynamic elastic modulus test values ​​due to the destruction of the internal structure. At the same time, it is beneficial to the control accuracy of the compression force.

[0018] At the same time, the second water-permeable plate acts as a water filter when draining liquid in the first space. Even if there is residual liquid in the second space, during the shrinkage test, after the liquid medium in the first space is drained, the adverse effect of the residual liquid on controlling the humidity in the first space can be effectively reduced due to the isolation of the second water-permeable plate.

[0019] In a specific embodiment, the elastic member is configured as a rubber pad, and the elastic member is disposed at the front end of the clamping rod (the pressure sensor is located between the end of the clamping rod and the elastic member). In this way, the flexibility of the elastic member is utilized to reduce peeling of the top of the core sample caused when providing a clamping force to the core sample. At the same time, the elastic member can be used to encapsulate the pressure sensor to prevent the pressure sensor from being directly exposed to the calcium hydroxide solution and being damaged prematurely, thereby reducing the corrosion resistance requirements for the pressure sensor.

[0020] In a specific embodiment, the clamping mechanism is a hydraulic cylinder or an electric push rod. When the clamping mechanism is a hydraulic cylinder, the clamping rod is a piston rod of the hydraulic cylinder. When the clamping mechanism is an electric push rod, the clamping rod is a push rod of the electric push rod.

[0021] It also includes a displacement sensor for detecting the displacement of the piston rod or push rod.

[0022] The above solution provides an implementation solution of a clamping mechanism in which the displacement of the clamping rod can be accurately obtained, and also provides an implementation solution including a displacement sensor.

[0023] In a specific embodiment, it further comprises a fourth space disposed at the bottom of the device box and isolated from the third space, wherein the lift pump is installed in the fourth space;

[0024] The inlet end of the lift pump is connected to a liquid inlet pipe with a one-way valve arranged thereon, and the outlet end of the lift pump is connected to a liquid outlet pipe with its outlet located in the second space.

[0025] The above scheme provides a technical solution for protecting the lifting pump by arranging the lifting pump in the fourth space so that the lifting pump is not directly exposed to the third space. At the same time, in this scheme, by arranging the lifting pump at the bottom of the device box, when the lifting pump is working, the liquid medium (saturated calcium hydroxide solution) in the third space can be used to absorb the vibration generated by the lifting pump, which is beneficial to maintaining the position stability of the core sample and preventing the core sample from tipping over. The one-way valve is used to prevent the liquid medium from flowing back through the liquid outlet pipe and the liquid inlet pipe after the liquid medium is injected into the first space, thereby facilitating the control of the liquid level in the first space during the swelling treatment process.

[0026] In a specific embodiment, the discharge pipeline includes a discharge pipe whose one end is connected to the second space and the other end is connected to the second space, and a control valve for controlling the discharge pipe to be turned on and off is connected in series on the discharge pipe. This solution provides a specific implementation of the discharge pipeline. Preferably, in order to enable the test device to operate automatically, the driver on the above control valve adopts an automated actuator. In order to have fewer supporting facilities, an electric actuator is preferably used.

[0027] In a specific embodiment, the number of the clamping mechanisms is multiple, and each clamping mechanism is equipped with an elastic member and a pressure sensor;

[0028] The front end of each clamping rod is provided with a first permeable plate fixed on the second permeable plate. The first permeable plate is a porous plate with multiple holes on the top and side surfaces. The holes on the top surface of the first permeable plate are connected with the holes on the side surfaces.

[0029] When the above scheme is implemented, core samples can be set at the front end of each clamping mechanism to simultaneously complete the dry-wet cycle durability test of multiple core samples. These core samples can be the same core samples or different core samples from different batches, so as to improve the processing efficiency of the dry-wet cycle durability test; it is further configured to also include a first water-permeable plate, and the above first water-permeable plate serves as a support platform for supporting the core samples on the second water-permeable plate. Based on such a structure, even if the second water-permeable plate has relatively sparse conducting holes in order to ensure the strength of the second water-permeable plate, the problem of sufficient contact between the bottom of the core sample and the liquid medium can be solved through the channels on the first water-permeable plate.

[0030] In a specific embodiment, the device box is provided with an operation window, the operation window serving as a communication channel connecting the first space with the outside of the operation window, and the size of the operation window satisfies: placing a test core sample from the outside into the first space, and taking the core sample out of the first space;

[0031] Also included is a door body for closing the operating window;

[0032] A frame is provided on the outer wall of the device box, a slot is formed between the frame and the outer wall of the device box, and the door body is installed on the device box by being plugged into the slot;

[0033] Also included is a sealing bolt threadedly connected to the frame, the sealing bolt can extend into the slot and provide a thrust for the door body toward the device box;

[0034] It also includes a sealing gasket fixed on the outer wall of the device box or on the inner wall of the door body. When the sealing gasket is fixed on the device box, the sealing gasket is arranged on the outer side of the operating window and extends along the circumferential direction of the operating window. When the sealing gasket is fixed on the door body, the sealing gasket is arranged at the edge of the door body and extends along the circumferential direction of the door body.

[0035] In this solution, the operation window can be opened and closed by operating the door body. When the operation window is opened, the core sample is placed and taken out. When the operation window is closed, the first space is closed as an environment for shrinkage treatment and an environment for swelling treatment. This solution aims to set the first space to have a larger space to meet the needs of completing multiple core sample treatments at the same time. When the operation window is set larger, how to conveniently shift the position of the door body to achieve the opening and closing adjustment of the operation window, and provide a specific solution for how to install the door body on the device box. Specifically, after the slot is formed by the frame, the door body can be conveniently adjusted to the position of opening the operation window and the position of closing the operation window by sliding under the constraint of the slot. After reaching the position of closing the operation window, the thrust provided by the sealing bolt to the door body can compress the sealing gasket to deform, so as to avoid leakage of the first space at the operation window position. On the other hand, this solution can avoid contact between the sealing bolt and the common calcium hydroxide solution used as the soaking liquid, which is beneficial to ensuring the reliability of the door body closing the first space. The door body can adjust its position in the slot by sliding up and down or left and right. In order to reduce the requirement for space width during operation of the device, the preferred application is to adjust the position of the door body in the slot by sliding up and down.

[0036] In a specific embodiment, the frame includes side frames arranged on both sides of the operating window and a bottom frame arranged below the operating window. The side frames and the bottom frame are angle steels with one edge welded to the device box. The edge of the angle steel of the side frame used for welding with the device box constitutes the boundary of the slot in the length direction, and the other edge of the angle steel of the side frame constitutes the boundary of the slot in the width direction. The edge of the angle steel of the bottom frame used for welding with the device box constitutes the boundary of the slot in the height direction, and the other edge of the angle steel of the bottom frame constitutes the boundary of the slot in the width direction. When the door body closes the operating window, the door body is supported on the edge of the angle steel of the bottom frame used for welding with the device box.

[0037] The frame also includes a top frame located above the bottom frame and below the top of the side frame, the top frame is a flat bar with two ends connected to different side frames respectively, and the inner side surface of the top frame constitutes the boundary of the slot in the width direction;

[0038] The side frame, the bottom frame and the top frame are all threadedly connected with sealing bolts.

[0039] The above scheme provides a specific implementation method of a frame for adjusting the position of the door body in the slot in an up and down sliding manner, specifically: after the angle steels serving as the side frames are welded, the slots on the two side frames are facing each other, and after the angle steels serving as the bottom frame are welded, the slots on the two side frames are facing upwards. In this way, the slots formed by the side frames, the bottom frame and the device box can limit the position of the door body in the left and right directions, the front and back directions, and the maximum position when inserted downward. For example, after being supported on the bottom frame, the door body is released and the sealing bolts are tightened to close the operating window. It is further configured to include a top frame, a top frame, a side frame and a bottom frame. The sealing bolts on the frame can force the sealing gaskets on both sides of the operating window to be compressed, which is beneficial to maintaining the sealing reliability of the first space; the position setting of the top frame can be coordinated with the strip grooves arranged on the bottom side of the outer surface of the door body. When the door body is lifted to the same height as the strip grooves and the sealing bolts on the top frame, the sealing bolts on the top frame are rotated to make these sealing bolts embed into the strip grooves and provide support for the door body. The support provided by the sealing bolts above the top frame and on the side frame for the door body can stably support the door body on the device box and keep the operating window below the door body in an open state.

[0040] In a specific embodiment, a detection device is further included, wherein the detection device is used to detect environmental parameters of the internal environment of the first space and the internal environment of the third space, the environmental parameters of the first space include temperature parameters and humidity parameters of the gas phase environment, and the environmental parameters of the third space include temperature parameters of the liquid phase environment;

[0041] The first space and the second space are both provided with liquid level gauges for displaying or detecting the liquid levels therein.

[0042] In the above scheme, the detection device is used to keep the medium parameters in the first space as the set parameters during shrinkage treatment and swelling treatment, and the liquid level meter is used to indicate whether the liquid storage amount in the third space and the amount of liquid medium in the first space meet the swelling treatment requirements.

[0043] Regarding the problem of accurately obtaining the core sample length change value and the core sample shrinkage rate or swelling rate by using the displacement of the pressing rod, in a specific embodiment, after the core sample completes the set number of dry-wet cycle treatments, the pressing mechanism provides the top of the core sample with the set size of pressing force, and in this state, the displacement of the pressing rod is detected by the displacement sensor to obtain the length of the core sample after completing the set number of dry-wet cycle treatments;

[0044] Combined with the baseline length of the core sample before the dry-wet cycle treatment, the shrinkage rate or swelling rate of the core sample after a set number of dry-wet cycle treatments is obtained. The shrinkage rate is obtained by the length value of the core sample in the dry shrinkage state, and the swelling rate is obtained by the length value of the core sample in the wet swelling state.

[0045] The present invention has at least the following beneficial effects:

[0046] This solution can avoid local micro-peeling of the core sample surface caused by transfer, which is beneficial to the accuracy of the test results of mass loss in dry-wet cycle durability; it can effectively improve the convenience of dry-wet cycle treatment tests; it provides a simple structural basis for realizing automatic control based on control modules and actuators, which can effectively reduce the manpower input required for the core sample characteristic test after grouting and ensure that the characteristic test is completed under standardized operation.

[0047] This solution can effectively ensure the stability of the core sample during the test. The structural setting provided by this solution can obtain the accurate length value required for the calculation of the shrinkage (wet expansion) rate of the core sample in the protection test, and can obtain a higher control accuracy of the clamping force of the clamping mechanism on the core sample.

[0048] The adverse effect of residual liquid in the second space on the humidity control in the first space is effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a cross-sectional view of a specific embodiment of the rock mass grouting core sample characteristic test device described in this scheme;

[0050] Figure 2 This is a front view of a specific embodiment of the core sample characteristic test device after rock mass grouting described in this scheme. The reference numerals in the figure are: 1, device box, 2, clamping mechanism, 3, elastic member, 4, pressure sensor, 5, core sample, 6, first permeable plate, 7, second permeable plate, 8, partition, 9, lifting pump, 10, first space, 11, second space, 12, third space, 13, detection device, 14, discharge pipeline, 15, operation window, 16, door body, 17, frame, 18, sealing bolt, 19, liquid level meter, 20, strip groove. DETAILED DESCRIPTION

[0051] The present invention is further described in detail below in conjunction with embodiments, but the present invention is not limited to the following embodiments:

[0052] Embodiment 1:

[0053] like Figure 1 to Figure 2 As shown, a core sample characteristic test device after rock mass grouting comprises a device box 1, wherein a second water-permeable plate 7 and a partition plate 8 are arranged in the device box 1, wherein the second water-permeable plate 7 and the partition plate 8 divide the space in the device box 1 into a first space 10, a second space 11 and a third space 12 which are arranged in sequence from top to bottom, wherein the second water-permeable plate 7 is located above the partition plate 8, wherein the first space 10 and the second space 11 are connected through the conducting hole on the second water-permeable plate 7, and the partition plate 8 divides the second space 11 and the third space 12 into isolation from each other;

[0054] It also includes a lift pump 9 for injecting the medium in the third space 12 into the second space 11;

[0055] It also includes a discharge pipeline 14 for discharging the medium in the second space 11 to the third space 12;

[0056] It also includes a clamping mechanism 2 installed on the top of the first space 10, the clamping mechanism 2 has a clamping rod facing the second water-permeable plate 7, and an elastic member 3 and a pressure sensor 4 are installed on the clamping rod. The elastic member 3 is used to achieve: when the clamping rod provides a clamping force to the core sample 5 thereunder, the clamping force is transmitted through the elastic member 3, and the pressure sensor 4 is used to measure the magnitude of the clamping force.

[0057] In the above scheme, the first space 10 is used as a space for shrinkage treatment of the core sample 5. Specifically, the core sample 5 is supported on the second permeable plate 7. The internal environment of the first space 10 is maintained as a gas phase environment for shrinkage treatment. The environmental control parameters include temperature parameters and humidity parameters. Since the temperature and humidity of the environment in the control box are conventional technical means, the relevant control means are not mentioned in the above scheme. One implementation method is to provide a gas phase circulation device for the first space 10. The gas phase circulation device is connected in series with a temperature control device and a humidity control device. The gas temperature and humidity in the first space 10 are processed by the gas phase circulation device so that the shrinkage treatment has the set gas phase environmental conditions. Similarly, for swelling treatment, it is generally required that the liquid medium (such as saturated calcium hydroxide solution) used for swelling treatment also has the same temperature as the gas temperature in the first space 10. Those skilled in the art can solve the problem without creative work. In this case, the liquid medium contained in the third space 12 can also be treated to have a required temperature. The first space 10 also serves as a space for performing swelling treatment on the core sample 5. Specifically, the liquid medium stored in the third space 12 is lifted to the second space 11 by the lifting pump 9, and the liquid medium further enters the first space 10 through the conducting hole on the second water-permeable plate 7. When the first space 10 has a liquid level that can immerse the core sample 5, the injection of the liquid medium is stopped, and the liquid level in the first space 10 is maintained for a set time to perform swelling treatment. After the swelling treatment is completed, the liquid medium is refluxed through the discharge pipe 14 to restore the first space 10 to a state for shrinkage treatment. Completing one shrinkage treatment and one swelling treatment is one dry-wet cycle. After repeating a set number of dry-wet cycles, the change value of the characteristic parameter of the core sample 5 relative to the baseline parameter before treatment is obtained. By comparing with the baseline parameter, test data such as shrinkage rate and swelling rate can be obtained.

[0058] Related to the above, the present solution also relates to a method for testing the properties of a core sample 5 after grouting of a rock mass. The method uses the test device as described above to perform a durability property test on the grouting core sample 5, and comprises the following steps:

[0059] S1, placing the test core sample 5 in the first space 10 and supporting it on the second water-permeable plate 7, and completing the shrinkage treatment of the core sample 5 for a set time by controlling the temperature and humidity of the gas phase environment in the first space 10;

[0060] S2, injecting the liquid medium for swelling treatment into the second space 11 through the lifting pump 9, and injecting the liquid medium into the first space 10 through the conducting hole on the second water-permeable plate 7, and forming a liquid level of a set height in the first space 10, completing the swelling treatment of the core sample 5 for a set time;

[0061] S3, after the swelling treatment is completed, the liquid medium in the first space 10 and the second space 11 is discharged into the third space 12 through the discharge pipeline 14, and the gas phase environment in the first space 10 is restored to the environmental conditions required for the shrinkage treatment, and steps S1 and S2 are repeated to perform a set number of dry-wet cycle treatments on the core sample 5;

[0062] In the process of injecting the liquid medium into the first space 10, the clamping mechanism 2 is used to provide a continuous clamping force on the top of the core sample 5, the clamping force is transmitted through the elastic member 3, and the clamping force is controlled to a set size through the feedback value of the pressure sensor 4. After the liquid medium is injected into the first space 10, the force of the clamping mechanism 2 on the top of the core sample 5 is removed, and the pressure sensor 4 is lifted above the liquid surface of the liquid medium by the clamping mechanism 2.

[0063] Compared with the prior art, the present solution integrates the shrinkage treatment and the swelling treatment of the core sample 5 in the first space 10, and realizes the environmental switching in the first space 10 through the lifting pump 9 and the discharge pipeline 14. Compared with the prior art in which the switching between the shrinkage treatment and the swelling treatment involves the transfer of the core sample 5 between different containers, the present solution can avoid the local micro-peeling of the surface of the core sample 5 caused by the transfer, which is beneficial to the accuracy of the test results of the mass loss in the dry-wet cycle durability; at the same time, since it does not involve related transfer, it can effectively improve the convenience of the test; at the same time, the transfer of the liquid medium between the first space 10 and the third space 12, the time control of the storage of the liquid medium in the first space 10, etc. can be completed through the commonly used control modules and actuators. For the dry-wet cycles of the core sample 5 up to hundreds of times, the present solution provides a simple structural basis for realizing automatic control based on the control module and the actuator, which can effectively reduce the manpower input required for the characteristic test of the core sample 5 after grouting and ensure that the characteristic test is completed under standardized operation.

[0064] At the same time, in this scheme, a second permeable plate 7 and a partition 8 are used to divide the space of the device box 1. The partition 8 plays the function of maintaining the liquid environment in the first space 10 during the wet expansion treatment, and the partition 8 plays the function of isolating the gas phase environment and the liquid phase environment during the shrinkage treatment, so as to facilitate the maintenance of the environmental parameters in the first space 10 during the shrinkage treatment. The second permeable plate 7 serves as a water distribution plate when the first space 10 is filled with liquid, which can effectively reduce the possibility of the first space 10 being washed, displaced and tipped over when the liquid is filled; the clamping mechanism 2 maintains the position stability and anti-lodging ability of the core sample 5 under the liquid filling condition, and after a set number of dry-wet cycle treatments, in cooperation with the pressure sensor 4, under the set clamping force on the core sample 5, it can not only protect the core sample 5, but also prevent the core sample 5 from being damaged under the clamping force. At the same time, for the reference length measurement of the core sample 5 and the length measurement after the dry-wet cycle treatment, when the pressure sensor 4 has the same measurement value and the measurement value is the set size, the length of the core sample 5 at different stages and the length change that occurs can be accurately obtained by measuring the displacement of the clamping rod. Therefore, the accurate length value required for the calculation of the shrinkage (wet expansion) rate can be obtained through this scheme; the clamping rod with an elastic member 3 can provide flexible compression for the core sample 5, which can effectively prevent the core sample 5 from being subjected to excessive compression force when being compressed due to the low displacement control accuracy of the clamping rod, resulting in surface peeling due to compression, resulting in inaccurate subsequent quality measurement results, or inaccurate subsequent length and dynamic elastic modulus test values ​​due to the destruction of the internal structure. At the same time, it is beneficial to the compression force control accuracy.

[0065] At the same time, the second water-permeable plate 7 acts as a water filter when draining the liquid in the first space 10. Even if there is residual liquid in the second space 11, during the shrinkage test, after the liquid medium in the first space 10 is drained, the isolation of the second water-permeable plate 7 can effectively reduce the adverse effect of the residual liquid on controlling the humidity in the first space 10.

[0066] In more detail, the elastic member 3 is configured as a rubber pad, and the elastic member 3 is disposed at the front end of the clamping rod (the pressure sensor 4 is located between the end of the clamping rod and the elastic member 3). In this way, the flexibility of the elastic member 3 is utilized to reduce peeling of the top of the core sample 5 caused when providing a clamping force to the core sample 5. At the same time, the elastic member 3 can be used to encapsulate the pressure sensor 4, thereby preventing the pressure sensor 4 from being directly exposed to the calcium hydroxide solution and being damaged prematurely, and reducing the corrosion resistance requirements for the pressure sensor 4.

[0067] In more detail, the clamping mechanism 2 is a hydraulic cylinder or an electric push rod. When the clamping mechanism 2 is a hydraulic cylinder, the clamping rod is the piston rod of the hydraulic cylinder. When the clamping mechanism 2 is an electric push rod, the clamping rod is the push rod of the electric push rod.

[0068] It also includes a displacement sensor for detecting the displacement of the piston rod or push rod.

[0069] The above solution provides an implementation solution of a clamping mechanism 2 in which the displacement of the clamping rod can be accurately acquired, and also provides an implementation solution including a displacement sensor.

[0070] More specifically, it also includes a fourth space disposed at the bottom of the device box 1 and isolated from the third space 12, and the lift pump 9 is installed in the fourth space;

[0071] The inlet end of the lift pump 9 is connected to a liquid inlet pipe provided with a one-way valve, and the outlet end of the lift pump 9 is connected to a liquid outlet pipe whose outlet is located in the second space 11 .

[0072] The above scheme provides a technical solution for protecting the lifting pump 9 by arranging the lifting pump 9 in the fourth space so that the lifting pump 9 is not directly exposed to the third space 12. At the same time, in this scheme, by arranging the lifting pump 9 at the bottom of the device box 1, when the lifting pump 9 is working, the liquid medium (saturated calcium hydroxide solution) in the third space 12 can be used to absorb the vibration generated by the lifting pump 9, which is beneficial to maintaining the position stability of the core sample 5 and preventing the core sample 5 from tipping over. The one-way valve is used to prevent the liquid medium from flowing back through the liquid outlet pipe and the liquid inlet pipe after the liquid medium is injected into the first space 10, so as to facilitate the control of the liquid level in the first space 10 during the swelling process.

[0073] More specifically, the discharge pipeline 14 includes a discharge pipe whose one end is connected to the second space 11 and the other end is connected to the second space 11, and a control valve for controlling the discharge pipe to be turned on and off is connected in series on the discharge pipe. This solution provides a specific implementation of the discharge pipeline 14. Preferably, in order to enable the test device to operate automatically, the driver on the above control valve adopts an automated actuator. For fewer supporting facilities, an electric actuator is preferably used.

[0074] More specifically, there are multiple pressing mechanisms 2, and each pressing mechanism 2 is equipped with an elastic member 3 and a pressure sensor 4;

[0075] The front end of each clamping rod is provided with a first water-permeable plate 6 fixed on the second water-permeable plate 7. The first water-permeable plate 6 is a porous plate with multiple holes on the top and side surfaces. The holes on the top surface of the first water-permeable plate 6 are connected to the holes on the side surfaces.

[0076] When the above scheme is implemented, a core sample 5 can be set at the front end of each clamping mechanism 2 to synchronously complete the dry-wet cycle durability test of multiple core samples 5. These core samples 5 can be the same core samples 5 or different core samples 5 from different batches, which are used to improve the processing efficiency of the dry-wet cycle durability test; it is further configured to also include a first water-permeable plate 6, and the above first water-permeable plate 6 serves as a support platform for supporting the core sample 5 on the second water-permeable plate 7. On the basis of such a structure, even if the second water-permeable plate 7 has relatively sparse conducting holes in order to ensure the strength of the second water-permeable plate 7, the problem of sufficient contact between the bottom of the core sample 5 and the liquid medium can be solved through the channels on the first water-permeable plate 6.

[0077] More specifically, the device box 1 is provided with an operation window 15, which serves as a communication passage connecting the first space 10 with the outside of the operation window 15, and the size of the operation window 15 satisfies: placing the test core sample 5 from the outside into the first space 10, and taking the core sample 5 out of the first space 10;

[0078] Also includes a door body 16 for closing the operation window 15;

[0079] A frame 17 is provided on the outer wall of the device box 1, and a slot is formed between the frame 17 and the outer wall of the device box 1. The door body 16 is installed on the device box 1 by being plugged into the slot;

[0080] It also includes a sealing bolt 18 threadedly connected to the frame 17, and the sealing bolt 18 can extend into the slot and provide a thrust for the door body 16 toward the device box 1;

[0081] It also includes a sealing gasket fixed on the outer wall of the device box 1 or on the inner wall of the door body 16. When the sealing gasket is fixed on the device box 1, the sealing gasket is arranged on the outer side of the operating window 15 and extends along the circumferential direction of the operating window 15. When the sealing gasket is fixed on the door body 16, the sealing gasket is arranged at the edge position of the door body 16 and extends along the circumferential direction of the door body 16.

[0082] In this solution, the operation window 15 can be opened and closed by operating the door body 16. When the operation window 15 is opened, the core sample 5 is taken and placed. When the operation window 15 is closed, the first space 10 is sealed as an environment for shrinkage treatment and an environment for swelling treatment. The present solution is aimed at setting the first space 10 to have a larger space to meet the need of completing the processing of multiple core samples 5 at the same time. When the operation window 15 is set to be larger, how to conveniently shift the position of the door body 16 to realize the opening and closing adjustment of the operation window 15, and provide a specific solution for how to install the door body 16 on the device box 1. Specifically, after a slot is formed by the frame 17, the door body 16 can be slid under the constraint of the slot to conveniently adjust the door body 16 to the position of opening the operation window 15 and the position of closing the operation window 15. After reaching the position of closing the operation window 15, the thrust provided by the sealing bolt 18 to the door body 16 can compress the sealing gasket to deform, thereby avoiding leakage of the first space 10 at the operation window 15 position. On the other hand, the present solution can avoid contact between the sealing bolt 18 and the common calcium hydroxide solution used as the immersion liquid, which is beneficial to ensuring the reliability of the door body 16 sealing the first space 10. The door body 16 can adjust its position in the slot by sliding up and down or left and right. In order to reduce the space width requirement during the operation of the device, it is better to adjust the position of the door body 16 in the slot by sliding up and down.

[0083] In more detail, the frame 17 includes side frames arranged on both sides of the operation window 15 and a bottom frame arranged below the operation window 15. The side frames and the bottom frame are angle steels with one edge welded to the device box 1. The edge of the angle steel of the side frame used for welding with the device box 1 constitutes the boundary of the slot in the length direction, and the other edge of the angle steel of the side frame constitutes the boundary of the slot in the width direction. The edge of the angle steel of the bottom frame used for welding with the device box 1 constitutes the boundary of the slot in the height direction, and the other edge of the angle steel of the bottom frame constitutes the boundary of the slot in the width direction. When the door body 16 closes the operation window 15, the door body 16 is supported on the edge of the angle steel of the bottom frame used for welding with the device box 1.

[0084] The frame 17 also includes a top frame located above the bottom frame and below the top of the side frame, the top frame is a flat bar with two ends connected to different side frames, and the inner side of the top frame constitutes the boundary of the slot in the width direction;

[0085] The side frames, the bottom frame and the top frame are all threadedly connected with sealing bolts 18.

[0086] The above scheme provides a specific implementation method of a frame 17 for adjusting the position of the door body 16 in the slot in an up and down sliding manner, specifically: after the angle steels serving as the side frames are welded, the slots on the two side frames are in a state of facing each other, and after the angle steels serving as the bottom frame are welded, the slots on the two side frames are facing upward, so that the slots formed by the side frames, the bottom frame and the device box 1 can limit the position of the door body 16 in the left and right directions, the position in the front and back directions, and the maximum position when inserted downward. For example, after being supported on the bottom frame, the door body 16 is released, and the sealing bolts 18 are tightened to close the operating window 15. It is further configured to include a top frame, and the sealing bolts 18 on the top frame, the side frames and the bottom frame can make The sealing gaskets on each side of the operating window 15 can be forced to be compressed, which is beneficial to maintaining the sealing reliability of the first space 10; the position setting of the top frame can be coordinated with the strip groove 20 arranged on the bottom side of the outer surface of the door body 16. When the door body 16 is lifted to the same height as the strip groove 20 and the sealing bolts 18 on the top frame, the sealing bolts 18 on the top frame are rotated so that these sealing bolts 18 are embedded in the strip groove 20 and provide support for the door body 16. The support provided by the sealing bolts 18 on the side frame above the top frame to the door body 16 can stably support the door body 16 on the device box 1 and keep the operating window 15 below the door body 16 in an open state.

[0087] More specifically, it also includes a detection device 13, which is used to detect environmental parameters of the internal environment of the first space 10 and the internal environment of the third space 12. The environmental parameters of the first space 10 include temperature parameters and humidity parameters of the gas phase environment, and the environmental parameters of the third space 12 include temperature parameters of the liquid phase environment;

[0088] The first space 10 and the second space 11 are both provided with a liquid level meter 19 for displaying or detecting the liquid level therein.

[0089] In the above scheme, the detection device 13 is used to keep the medium parameters in the first space 10 as the set parameters during shrinkage treatment and swelling treatment, and the liquid level meter 19 is used to indicate whether the liquid storage amount in the third space 12 and the amount of liquid medium in the first space 10 meet the swelling treatment requirements.

[0090] Regarding the problem of accurately obtaining the length change value of the core sample 5 and obtaining the shrinkage rate or swelling rate of the core sample 5 by using the displacement of the pressing rod, in more detail, after the core sample 5 completes the set number of dry-wet cycle treatments, the pressing mechanism 2 provides the top of the core sample 5 with the set size of the pressing force, and in this state, the displacement of the pressing rod is detected by the displacement sensor to obtain the length of the core sample 5 after completing the set number of dry-wet cycle treatments;

[0091] Combined with the reference length of the core sample 5 before the dry-wet cycle treatment, the shrinkage rate or swelling rate of the core sample 5 after a set number of dry-wet cycle treatments is obtained. The shrinkage rate is obtained by the length value of the core sample 5 in the shrunk state, and the swelling rate is obtained by the length value of the core sample 5 in the swollen state.

[0092] 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 device for testing the properties of core samples after grouting of rock mass, comprising a device box (1), characterized in that: The device box (1) is provided with a second water-permeable plate (7) and a partition plate (8), the second water-permeable plate (7) and the partition plate (8) divide the space in the device box (1) into a first space (10), a second space (11) and a third space (12) arranged in sequence from top to bottom, the second water-permeable plate (7) is located above the partition plate (8), the first space (10) and the second space (11) are connected to each other through the conducting hole on the second water-permeable plate (7), and the partition plate (8) divides the second space (11) and the third space (12) into mutually isolated spaces; It also includes a lift pump (9) for injecting the medium in the third space (12) into the second space (11); It also includes a discharge pipeline (14) for discharging the medium in the second space (11) to the third space (12); It also includes a clamping mechanism (2) installed at the top of the first space (10), the clamping mechanism (2) having a clamping rod facing the second water-permeable plate (7), an elastic member (3) and a pressure sensor (4) installed on the clamping rod, the elastic member (3) being used to achieve: when the clamping rod provides a clamping force to the core sample (5) below it, the clamping force is transmitted through the elastic member (3), and the pressure sensor (4) is used to measure the magnitude of the clamping force.

2. The rock mass core sample characteristic test device after grouting according to claim 1 is characterized in that: The clamping mechanism (2) is a hydraulic cylinder or an electric push rod. When the clamping mechanism (2) is a hydraulic cylinder, the clamping rod is a piston rod of the hydraulic cylinder. When the clamping mechanism (2) is an electric push rod, the clamping rod is a push rod of the electric push rod. It also includes a displacement sensor for detecting the displacement of the piston rod or push rod.

3. The rock mass core sample characteristic test device after grouting according to claim 1, characterized in that: It also includes a fourth space which is arranged at the bottom of the device box (1) and is isolated from the third space (12), and the lift pump (19) is installed in the fourth space; The inlet end of the lift pump (9) is connected to a liquid inlet pipe on which a one-way valve is arranged, and the outlet end of the lift pump (9) is connected to a liquid outlet pipe whose outlet is located in the second space (11).

4. The rock mass core sample characteristic test device after grouting according to claim 1, characterized in that: The discharge pipeline (14) comprises a discharge pipe whose one end is in communication with the second space (11) and whose other end is in communication with the second space (12); a control valve for controlling the on and off of the discharge pipe is connected in series to the discharge pipe.

5. The rock mass core sample characteristic test device after grouting according to claim 1, characterized in that: The number of the clamping mechanisms (2) is plural, and each clamping mechanism (2) is equipped with an elastic member (3) and a pressure sensor (4); The front end of each clamping rod is provided with a first water-permeable plate (6) fixed on the second water-permeable plate (7), the first water-permeable plate (6) is a porous plate having a plurality of holes on the top surface and the side surface, and each hole on the top surface of the first water-permeable plate (6) is connected with the hole on the side surface.

6. The rock mass core sample characteristic test device after grouting according to claim 1, characterized in that: The device box (1) is provided with an operation window (15), the operation window (15) serving as a communication passage connecting the first space (10) and the outside of the operation window (15), and the size of the operation window (15) is such that: a test core sample (5) can be placed from the outside into the first space (10), and the core sample (5) can be taken out of the first space (10); It also includes a door body (16) for closing the operating window (15); A frame (17) is provided on the outer wall of the device box (1), a slot is formed between the frame (17) and the outer wall of the device box (1), and the door body (16) is installed on the device box (1) by being plugged into the slot; It also includes a sealing bolt (18) threadedly connected to the frame (17), wherein the sealing bolt (18) can extend into the slot and provide a thrust for the door body (16) toward the device box (1); It also includes a sealing gasket fixed on the outer wall of the device box (1) or fixed on the inner wall of the door body (16); when the sealing gasket is fixed on the device box (1), the sealing gasket is arranged on the outer side of the operating window (15) and extends along the circumferential direction of the operating window (15); when the sealing gasket is fixed on the door body (16), the sealing gasket is arranged at the edge of the door body (16) and extends along the circumferential direction of the door body (16).

7. The rock mass core sample characteristic test device after grouting according to claim 6, characterized in that: The frame (17) comprises side frames arranged on both sides of the operating window (15) and a bottom frame arranged below the operating window (15); the side frames and the bottom frame are both angle steels with one edge welded to the device box (1); the edge of the angle steel of the side frame used for welding to the device box (1) constitutes the boundary of the slot in the length direction; the other edge of the angle steel of the side frame constitutes the boundary of the slot in the width direction; the edge of the angle steel of the bottom frame used for welding to the device box (1) constitutes the boundary of the slot in the height direction; the other edge of the angle steel of the bottom frame constitutes the boundary of the slot in the width direction; when the door body (16) closes the operating window (15), the door body (16) is supported on the edge of the angle steel of the bottom frame used for welding to the device box (1); The frame (17) further comprises a top frame located above the bottom frame and below the top end of the side frame, the top frame being a flat bar with two ends respectively connected to different side frames, and the inner side surface of the top frame forming a boundary in the width direction of the slot; The side frame, the bottom frame and the top frame are all threadedly connected with sealing bolts (18).

8. The rock mass core sample characteristic test device after grouting according to any one of claims 1 to 7, characterized in that: It also includes a detection device (13), the detection device (13) is used to detect environmental parameters of the internal environment of the first space (10) and the internal environment of the third space (12), the environmental parameters of the first space (10) include temperature parameters and humidity parameters of the gas phase environment, and the environmental parameters of the third space (12) include temperature parameters of the liquid phase environment; The first space (10) and the second space (12) are both provided with a liquid level meter (19) for displaying or detecting the liquid level therein.

9. A method for testing the properties of core samples after grouting of rock mass, characterized in that: The method uses the test device described in any one of claims 1 to 8 to conduct a durability property test on a grouted core sample (5), comprising the following steps: S1, placing the test core sample (5) in the first space (10) and supporting it on the second water-permeable plate (7), and completing the shrinkage treatment of the core sample (5) for a set time by controlling the temperature and humidity of the gas phase environment in the first space (10); S2, injecting a liquid medium for swelling treatment into the second space (11) through the lifting pump (9), and injecting the liquid medium into the first space (10) through the conducting hole on the second water-permeable plate (7), and forming a liquid level of a set height in the first space (10), completing the swelling treatment of the core sample (5) for a set time; S3, after the wet expansion treatment is completed, the liquid medium in the first space (10) and the second space (11) is discharged into the third space through the discharge pipeline (14), the gas phase environment in the first space (10) is restored to the environmental conditions required for the shrinkage treatment, and steps S1 and S2 are repeated to perform a set number of dry-wet cycle treatments on the core sample; In the process of injecting the liquid medium into the first space (10), the clamping mechanism (2) is used to provide a continuous clamping force on the top of the core sample (5), the clamping force is transmitted through the elastic member (3), and the clamping force is controlled to a set value through the feedback value of the pressure sensor (4). After the liquid medium is injected into the first space (10), the force of the clamping mechanism (2) on the top of the core sample (5) is removed, and the pressure sensor (4) is lifted to above the liquid surface of the liquid medium through the clamping mechanism (2).

10. The method for testing the properties of core samples after grouting of rock mass according to claim 9, characterized in that: After the core sample (5) has completed the set number of dry-wet cycle treatments, the pressing mechanism (2) provides the top of the core sample (5) with the set pressing force, and in this state, the displacement of the pressing rod is detected by the displacement sensor to obtain the length of the core sample (5) after the set number of dry-wet cycle treatments; Combined with the reference length of the core sample (5) before the dry-wet cycle treatment, the shrinkage rate or wet swelling rate of the core sample (5) after the set number of dry-wet cycle treatments is obtained, wherein the shrinkage rate is obtained by the length value of the core sample (5) in the dry shrinkage state, and the wet swelling rate is obtained by the length value of the core sample (5) in the wet swelling state.

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