Plate under-foaming time control device and method thereof

Abstract

This invention relates to the field of pavement repair technology, specifically disclosing a grouting time control device and method under slabs. The grouting time control device includes an installation sleeve, a control unit, and an alarm component. The installation sleeve is fitted onto the grouting pipe and has a split structure. A pressure sensor, a pipe wall vibration sensor, and a flow rate monitor are installed on the installation sleeve. The pressure sensor monitors the grouting pressure inside the grouting pipe, the pipe wall vibration sensor monitors the vibration frequency of the grouting pipe during the grouting process, and the flow rate monitor monitors the flow rate of the grout inside the grouting pipe. The control unit controls the opening and closing of the grouting equipment. The alarm component, pressure sensor, pipe wall vibration sensor, and flow rate monitor are all electrically connected to the control unit. This invention comprehensively determines the grouting time under slabs by considering the pressure inside the grouting pipe, the pipe wall vibration frequency, the grout flow rate inside the pipe, and the grout concentration at near holes or gaps, thus avoiding excessive or insufficient grouting.

Description

Technical Field

[0001] This invention relates to the field of road repair technology, and in particular to a device and method for controlling the grouting time under slabs. Background Technology

[0002] After prolonged use, cement pavements often develop defects such as cracks, misalignment, pumping, and corner fractures. The primary cause of these defects is voids beneath the pavement slabs. During maintenance, damaged slabs are typically removed using excavators and replaced with new slabs. However, during the removal of old slabs, the excavation reaches a certain depth below the pavement layer. The vibration from the excavator causes subgrade soil beneath adjacent slabs to loosen, creating voids that are difficult to detect visually. This leads to stress redistribution in both the new and replacement slabs. As traffic continues through the adjacent slabs, the void area and depth continue to increase, expanding the void area beneath the joint between the old and new slabs. Both the new and replacement slabs eventually form cantilever structures, and corner fractures recur shortly after replacement, affecting road traffic.

[0003] The time required for voids to form under concrete pavement slabs is complex and variable due to geological conditions and other factors. Under-slab grouting is commonly used to reinforce these slabs and ensure their strength. When using under-slab grouting, the grouting time is the most critical parameter for grouting quality. Current methods for controlling the grouting time include observing the pressure of the grouting machine and the leakage of grout from adjacent holes or transverse joints, which rely on the experience of technical personnel. These methods are prone to error, easily resulting in excessive or insufficient grouting, voids, and failure to meet grouting pressure specifications. Furthermore, the entire grouting process requires the coordinated participation of multiple personnel, which is not only inefficient but also time-consuming and labor-intensive. Therefore, there is an urgent need to provide an under-slab grouting time control device to solve the aforementioned technical problems. Summary of the Invention

[0004] The purpose of this invention is to provide a grouting time control device and method under the slab to solve the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides a grouting time control device under a slab, comprising:

[0006] An installation sleeve is fitted onto the grouting pipe, and the installation sleeve is a split structure.

[0007] A pressure sensor, a pipe wall vibration sensor, and a flow rate monitor are installed on the installation sleeve. The pressure sensor is used to monitor the grouting pressure inside the grouting pipe, the pipe wall vibration sensor is used to monitor the vibration frequency of the grouting pipe during the grouting process, and the flow rate monitor is used to monitor the flow rate of the grout inside the grouting pipe.

[0008] The control unit is used to control the opening and closing of the grouting equipment. The pressure sensor, the pipe wall vibration sensor and the flow rate monitor are all electrically connected to the control unit.

[0009] An alarm component is electrically connected to the control unit and is used to provide voice prompts based on instructions issued by the control unit.

[0010] Preferably, the mounting sleeve includes a first tube segment and a second tube segment, both of which are semi-circular structures. Connecting plates are fixedly connected to both sides of the first and second tube segments, and the connecting plates are arranged along the axial direction of the mounting sleeve. Connecting holes are provided on the connecting plates, and bolts are installed in the connecting holes. The first tube segment and the second tube segment are detachably connected via the connecting plates and the bolts. The pressure sensor, the pipe wall vibration sensor, and the flow rate monitor are all mounted on the first tube segment.

[0011] Preferably, a positioning sleeve is fixedly installed on the inner wall of the first segment, and the positioning sleeve is coaxially arranged with the pressure sensor and the flow rate monitor respectively. A connection port is opened on the grouting pipe, and the positioning sleeve is slidably installed in the connection port.

[0012] Preferably, a sealing gasket is fixedly installed on the inner wall of the first tube segment, and the sealing gasket is respectively sleeved on the outer side of the positioning sleeve, with a gap between the sealing gasket and the positioning sleeve.

[0013] Preferably, the height of the positioning sleeve is consistent with the wall thickness of the grouting pipe.

[0014] The present invention also provides a method for controlling the grouting time under the slab, which employs a grouting time control device under the slab and specifically includes the following steps:

[0015] Step 1: Determine the grouting location under the cement pavement slab and estimate the grouting volume;

[0016] Step 2: The arrival and installation of grouting equipment and the preparation of grout;

[0017] Step 3: Install a monitoring device at the outlet end of the grouting pipe by installing a sleeve;

[0018] The monitoring device is one or more of the following: pressure sensor, pipe wall vibration sensor, and flow rate monitor;

[0019] Step 4: Set the threshold parameters of the monitoring device through the control unit, and set the grouting time stop condition;

[0020] Step 5: Grouting under the cement pavement slab;

[0021] Step 6: The control unit determines whether to stop grouting based on the preset grouting time stop condition. If grouting is stopped, an alarm is issued.

[0022] Preferably, during the grouting process under the cement pavement slab, if water first emerges and then grout emerges from adjacent holes or transverse joints, the concentration of the grout that emerges needs to be tested. In this case, the grouting time of the grouting equipment must ensure that the concentration of the grout that emerges is consistent with the standard grout concentration.

[0023] Preferably, the concentration of the slurry is detected using concentration test paper. When the colored radius of the titration diffusion of the slurry is not less than the colored radius of the titration diffusion of the standard concentration slurry, the concentration detection result of the slurry meets a condition for stopping grouting.

[0024] Preferably, when there are at least two types of monitoring devices, if a threshold parameter is reached in one of the monitoring devices, the deformation of the slab surface needs to be monitored by a slab surface deformation sensor to determine whether grouting needs to continue. The criterion for determination is whether the deformation of the cement pavement slab is within the design range.

[0025] If the deformation of the cement pavement exceeds the design range, grouting shall be stopped immediately; if the deformation of the cement pavement is within the design range, grouting shall continue until all monitoring devices reach the threshold parameters, at which point grouting shall be stopped.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] This invention comprehensively considers factors such as the pressure inside the grouting pipe, the vibration frequency of the pipe wall, the grout flow rate inside the pipe, and the grout concentration at the holes or gaps to determine the grouting time under the slab, thus avoiding excessive or insufficient grouting. This invention reduces errors caused by technicians relying on experience, lowers the construction difficulty for technicians in controlling the grouting time, reduces personnel involvement in the entire grouting process, and improves work efficiency and the accuracy of grouting volume. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram showing the connection between the installation sleeve and the grouting pipe of the present invention;

[0030] Figure 2 This is a schematic diagram of the inner structure of segment one of the present invention;

[0031] Figure 3This is a schematic diagram illustrating the detection of grout concentration in adjacent holes or transverse seams according to the present invention;

[0032] Figure 4 This is a flowchart of the grouting process under the cement pavement slab according to the present invention;

[0033] In the diagram: 1. Grouting pipe; 2. Pressure sensor; 3. Pipe wall vibration sensor; 4. Flow rate monitor; 5. Pipe segment one; 6. Pipe segment two; 7. Connecting plate; 8. Positioning sleeve; 9. Sealing gasket. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. The described embodiments are merely some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] This invention provides a grouting time control device under a slab, comprising:

[0036] An installation sleeve is fitted onto the grouting pipe 1; the installation sleeve is a split structure.

[0037] The monitoring device installed on the installation sleeve includes a pressure sensor 2, a pipe wall vibration sensor 3, and a flow rate monitor 4. The pressure sensor 2 is used to monitor the grouting pressure in the grouting pipe 1, the pipe wall vibration sensor 3 is used to monitor the vibration frequency of the grouting pipe 1 during the grouting process, and the flow rate monitor 4 is used to monitor the flow rate of the grout in the grouting pipe 1.

[0038] The control unit is used to control the opening and closing of the grouting equipment. The pressure sensor 2, the pipe wall vibration sensor 3, and the flow rate monitor 4 are all electrically connected to the control unit.

[0039] An alarm component is electrically connected to the control unit and is used to provide voice prompts based on instructions issued by the control unit.

[0040] By setting pressure sensor 2 to monitor grouting pressure, when the pressure value fluctuates within a certain threshold range or suddenly increases to a larger pressure value exceeding the threshold, it proves that the grouting under the plate has been completed and can automatically sound an alarm, thus helping to determine the grouting time.

[0041] Furthermore, during the grouting operation, if the volume of voids under the slab is large at the beginning of grouting, the pressure under the slab is relatively small, and the grout in the grouting pipe 1 moves continuously at a relatively uniform speed. During this process, the impact on the grouting pipe 1 is minimal, and the vibration of the grouting pipe 1 is small. However, if the volume of voids under the slab is nearly full, the pressure under the slab is larger, and the grout in the grouting pipe 1 flows at an uneven speed. During this process, the impact on the grouting pipe 1 is greater, and the vibration of the grouting pipe 1 is larger. Therefore, by adding a pipe wall vibration sensor 3 to the grouting pipe 1, an automatic audible alert can be issued when its vibration characteristics reach a certain threshold, thus helping to determine the grouting time.

[0042] Furthermore, at the start of grouting, the grouting slurry in grouting pipe 1 has a high flow rate and velocity. However, if the volume under the slab is nearly full, the pressure under the slab will be high, causing the grouting slurry in grouting pipe 1 to flow at an uneven speed, with a lower flow rate and velocity during this process. Therefore, to prevent blockage of grouting pipe 1, a flow rate monitor 4 is installed on grouting pipe 1. When the flow rate falls below a certain threshold, it will automatically emit an audible warning, thus helping to determine the grouting time.

[0043] This invention comprehensively considers the internal pressure of the grouting pipe 1, the vibration frequency of the pipe wall, the flow rate of the grout inside the pipe, and the concentration of grout escaping from near holes or gaps to determine the grouting time under the slab, thus avoiding situations where the grouting volume is too high or too low. This invention can reduce errors caused by technicians relying on experience, lower the construction difficulty for technicians to control the grouting time, reduce the degree of personnel involvement in the entire grouting process, and improve work efficiency and the accuracy of the grouting volume.

[0044] Furthermore, to facilitate the installation of monitoring devices on the grouting pipe 1, the installation sleeve includes pipe segment 5 and pipe segment 6. Both pipe segment 5 and pipe segment 6 are semi-circular structures. Connecting plates 7 are fixedly connected to both sides of pipe segment 5 and pipe segment 6. The connecting plates 7 are arranged along the axial direction of the installation sleeve. Connecting holes are opened on the connecting plates 7, and bolts are installed in the connecting holes. Pipe segment 5 and pipe segment 6 are detachably connected through the connecting plates 7 and bolts. Pressure sensor 2, pipe wall vibration sensor 3 and flow rate monitor 4 are all installed on pipe segment 5.

[0045] When in use, after installing the grouting pipe 1 into place through the grouting hole, install the pipe segment 5 and the pipe segment 6 to the outlet end of the grouting pipe 1, and ensure that the use of the monitoring device is not affected, so as to avoid the impact of leakage of the grouting pipe 1 during the grouting process and ensure more accurate control of the grouting time.

[0046] Furthermore, to facilitate the installation and positioning of the installation sleeve and to ensure the stability of the installation sleeve after installation, a positioning sleeve 8 is fixedly installed on the inner wall of the pipe segment 5. The positioning sleeve 8 is coaxially set with the pressure sensor 2 and the flow rate monitor 4 respectively. A connection port is opened on the grouting pipe 1, and the positioning sleeve 8 is slidably installed in the connection port.

[0047] When using it, first align the positioning sleeve 8 with the connection port on the grouting pipe 1, and install the positioning sleeve 8 into the connection port. At this time, the installation of segment 1 5 is completed. Then, install segment 2 6 onto segment 1 5 with bolts. This completes the installation of the positioning sleeve. The positioning sleeve 8 not only helps to position segment 1 5, but also has a certain sealing effect on the connection port on the grouting pipe 1, thereby reducing the leakage of grout during the grouting process.

[0048] Furthermore, to prevent grout leakage due to the connection port, a sealing gasket 9 is fixedly installed on the inner wall of segment 5. The sealing gasket 9 is respectively fitted on the outside of the positioning sleeve 8, and a gap is provided between the sealing gasket 9 and the positioning sleeve 8.

[0049] Furthermore, to avoid the positioning sleeve 8 affecting the flow of grout in the grouting pipe 1, and to reduce the error caused by the vibration of the grouting slurry colliding with the positioning sleeve 8 to the pipe wall vibration sensor 3, the height of the positioning sleeve 8 is consistent with the wall thickness of the grouting pipe 1.

[0050] The present invention also provides a method for controlling the grouting time under the slab, which employs a grouting time control device under the slab and specifically includes the following steps:

[0051] Step 1: Determine the grouting location under the cement pavement slab and estimate the grouting volume; this prevents material waste and avoids damage to the cement pavement slab caused by excessive local pressure due to excessive grouting in a single operation.

[0052] Step 2: The arrival and installation of grouting equipment and the preparation of grout;

[0053] Step 3: Install a monitoring device at the outlet end of grouting pipe 1 by installing a sleeve;

[0054] The monitoring device is one or more of the following: pressure sensor 2, pipe wall vibration sensor 3, and flow rate monitor 4;

[0055] Step 4: Set the threshold parameters of the monitoring device through the control unit, and set the grouting time stop condition;

[0056] Among them, the pressure threshold is the design pressure value, the pipe wall vibration frequency threshold is 120Hz, and the slurry flow velocity threshold in the pipe is 30% of the initial flow velocity.

[0057] The method for determining the pipeline vibration frequency threshold is as follows:

[0058] 1. The vibration frequency of the grouting pipeline is denoted as F, and F = ax α +by β +cz rWhere a, b, and c are constants, x is the flow velocity of grout in grouting pipe 1 in L / min; y is the pressure in grouting pipe 1 in MPa; and Z is the diameter-to-thickness ratio of grouting pipe 1.

[0059] 2. The grouting end time, controlled by the experience of technicians, was determined through on-site grouting tests. The grouting effect was verified by drilling core samples at the grouting port with the same depth as the grouting. When the height of the grouting material reached the road surface layer, it was considered that the grouting time was well controlled. The flow velocity of the grout in the pipe, the pressure, and the pipe diameter-to-thickness ratio at the moment of stopping grouting were statistically analyzed. Finally, the relationship between the pipe vibration frequency and the three factors was obtained through numerical fitting.

[0060] 3. When the flow velocity of the grout in the grouting pipe 1 is 30% of the initial velocity and the pressure in the grouting pipe 1 is the design pressure value, and the diameter-to-thickness ratio of the grouting pipe 1 is known, the vibration frequency threshold of the grouting pipe is a fixed value.

[0061] Step 5: Grouting under the cement pavement slab;

[0062] Step 6: The control unit determines whether to stop grouting based on the preset condition program. If grouting is stopped, an alarm is issued.

[0063] In this invention, the grouting process under the cement pavement slab is carried out in multiple stages, as detailed below:

[0064] Step 5.1: Multiple grouting holes are opened on the panel corresponding to the void position under the cement pavement panel, and the grouting holes are distributed in a dispersed manner;

[0065] Step 5.2: Grouting operations are performed sequentially in multiple grouting holes. The grouting volume of a single grouting hole is the estimated grouting volume divided by the number of grouting holes.

[0066] Furthermore, during the grouting process under the cement pavement slab, if water first emerges and then grout emerges from adjacent holes or transverse joints, the concentration of the emerging grout needs to be tested. In this case, the grouting time of the grouting equipment must ensure that the concentration of the emerging grout is consistent with the concentration of the standard grout. The concentration of the emerging grout is tested using concentration test paper. When the colored radius of the titration diffusion of the emerging grout is not less than the colored radius of the titration diffusion of the standard concentration grout, the concentration test result of the emerging grout meets a condition for stopping the grouting equipment.

[0067] Furthermore, if there is no situation where water first oozes out and then grout oozes out in adjacent holes or transverse joints, and there are no fewer than two types of monitoring devices, after the threshold parameter is reached in the monitoring device, the deformation of the slab surface needs to be monitored by the slab surface deformation sensor to determine whether grouting needs to continue. The criterion for judgment is whether the deformation of the cement pavement slab is within the design range.

[0068] If the deformation of the cement pavement exceeds the design range, grouting shall be stopped immediately; if the deformation of the cement pavement is within the design range, grouting shall continue until all monitoring devices reach the threshold parameters, at which point grouting shall be stopped.

[0069] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A plate under-foaming time control device, characterized by, include: An installation sleeve is fitted onto the grouting pipe (1), and the installation sleeve is a split structure; A pressure sensor (2), a pipe wall vibration sensor (3), and a flow rate monitor (4) are installed on the installation sleeve. The pressure sensor (2) is used to monitor the grouting pressure in the grouting pipe (1). The pipe wall vibration sensor (3) is used to monitor the pipe wall vibration frequency caused by the change in grout flow rate due to the change in the volume of the void under the plate during the grouting process. The flow rate monitor (4) is used to monitor the flow rate of the grout in the grouting pipe (1). The control unit is used to control the opening and closing of the grouting equipment. The pressure sensor (2), the pipe wall vibration sensor (3) and the flow rate monitor (4) are all electrically connected to the control unit. An alarm component is electrically connected to the control unit and is used to provide voice prompts based on instructions issued by the control unit.

2. The board under-foaming time control device according to claim 1, characterized by The mounting sleeve includes a first segment (5) and a second segment (6). Both the first segment (5) and the second segment (6) are semi-circular structures. Both sides of the first segment (5) and the second segment (6) are fixedly connected to a connecting plate (7). The connecting plate (7) is arranged along the axial direction of the mounting sleeve. The connecting plate (7) has a connecting hole, and a bolt is installed in the connecting hole. The first segment (5) and the second segment (6) are detachably connected through the connecting plate (7) and the bolt. The pressure sensor (2), the pipe wall vibration sensor (3), and the flow rate monitor (4) are all installed on the first segment (5).

3. The board under-pinning time control apparatus according to claim 2, characterized by A positioning sleeve (8) is fixedly installed on the inner wall of the first segment (5). The positioning sleeve (8) is coaxially arranged with the pressure sensor (2) and the flow rate monitor (4). A connection port is opened on the grouting pipe (1), and the positioning sleeve (8) is slidably installed in the connection port.

4. The board under-pinning time control apparatus according to claim 3, characterized by A sealing gasket (9) is fixedly installed on the inner wall of the tube segment (5). The sealing gasket (9) is respectively sleeved on the outside of the positioning sleeve (8). A gap is provided between the sealing gasket (9) and the positioning sleeve (8).

5. The board under-pinning time control apparatus according to claim 3, characterized by The height of the positioning sleeve (8) is consistent with the wall thickness of the grouting pipe (1).

6. A method of controlling the time of sub-plate grouting, characterized by, The grouting time control device under the slab as described in any one of claims 1-5 specifically includes the following steps: Step 1: Determine the grouting location under the cement pavement slab and estimate the grouting volume; Step 2: The arrival and installation of grouting equipment and the preparation of grout; Step 3: Install a monitoring device at the outlet end of the grouting pipe (1) by installing a sleeve; The monitoring devices include a pressure sensor (2), a pipe wall vibration sensor (3), and a flow rate monitor (4). Step 4: Set the threshold parameters of the monitoring device through the control unit, and set the grouting time stop condition; Step 5: Grouting under the cement pavement slab; Step 6: The control unit determines whether to stop grouting based on the preset grouting time stop condition. If grouting is stopped, an alarm is issued.

7. The board under-pinning time control method according to claim 6, characterized by, During the grouting process under the cement pavement slab, if water first emerges and then grout emerges from adjacent holes or transverse joints, the concentration of the emerging grout needs to be tested. In this case, the grouting time of the grouting equipment must ensure that the concentration of the emerging grout is consistent with the standard grout concentration.

8. The board under-pinning time control method according to claim 7, characterized by, The concentration of the slurry is detected using concentration test paper. When the colored radius of the titration diffusion of the slurry is not less than the colored radius of the titration diffusion of the standard concentration slurry, the concentration detection result of the slurry meets a condition for stopping grouting.

9. The board under-pinning time control method according to claim 7, characterized by, When there are at least two types of monitoring devices, if the threshold parameter is reached in the monitoring device, the deformation of the slab surface needs to be monitored by the slab surface deformation sensor to determine whether grouting needs to continue. The criterion for judgment is whether the deformation of the cement pavement slab is within the design range. If the deformation of the cement pavement exceeds the design range, grouting shall be stopped immediately; if the deformation of the cement pavement is within the design range, grouting shall continue until all monitoring devices reach the threshold parameters, at which point grouting shall be stopped.

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