Tunneling excavation grouting slurry loss monitoring method and system

Abstract

The application provides a tunnel subsurface excavation grouting slurry loss monitoring method, which comprises the following steps: obtaining the light transmittance change condition in a detection position, and converting the obtained light transmittance change condition into an electric analog signal; performing digital processing on the converted analog signal, and outputting a discrete digital signal; performing segmented fitting on the discrete digital signal, obtaining a continuous segmented function signal about the light transmittance change, and performing gradient solving on the continuous segmented function of the light transmittance change; performing two-side segmented gradient weighted solving on the gradient singular points of the continuous segmented function to obtain a gradient change function signal; and monitoring the tunnel subsurface excavation grouting slurry loss condition of the detection position according to the continuous segmented function signal about the light transmittance change, the gradient change function signal and corresponding preset threshold values. The application also provides a tunnel subsurface excavation grouting slurry loss monitoring system, which effectively improves the reliability and accuracy of tunnel subsurface excavation grouting slurry loss monitoring.

Description

Technical Field

[0001] This invention relates to the field of tunnel grouting engineering, and in particular to a method and system for monitoring the loss of grout during tunnel grouting. Background Technology

[0002] With the rapid development of tunnel construction, grouting is often used during tunnel excavation to inject grout into the rock and soil to cope with adverse geological hazards such as water inrush, mud inrush, and rock fracturing. Due to the poor lighting inside the tunnel, grout inevitably seeps out from the injection port or from rock fissures during the grouting process, and the grout loss is difficult for personnel inside the tunnel to detect in the first instance.

[0003] During tunnel grouting, the loss of grout material results in significant material waste. Furthermore, substantial grout loss reflects errors in the grouting plan or grout mix design. Therefore, the grout mix ratio in grouting projects needs to be dynamically adjusted based on site conditions, making timely monitoring of grout loss crucial.

[0004] Traditional methods rely on manual inspection and observation to determine slurry loss. The effectiveness of these observations often depends on the experience of the observers, which introduces uncertainty. Furthermore, observers can generally only qualitatively describe slurry loss, not quantitatively record it. The reliability and accuracy of these records are difficult to ascertain, and there is a lack of professional monitoring methods.

[0005] In conclusion, during the grouting process of tunnel excavation, it is necessary to strengthen the monitoring of grout loss. It is particularly important to determine the grout loss situation through quantitative description and analysis, so as to better adjust the grouting material ratio and grouting engineering measures. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention innovatively proposes a method and system for monitoring grout loss in tunnel excavation, effectively solving the problem of low reliability and accuracy in monitoring grout loss in tunnel excavation caused by the prior art, and effectively improving the reliability and accuracy of grout loss monitoring in tunnel excavation.

[0007] The first aspect of this invention provides a method for monitoring the loss of grout during tunnel excavation, comprising:

[0008] The transmittance changes in the area to be tested are obtained, and the obtained transmittance changes are converted into an electrical analog signal;

[0009] The converted analog signal is digitized, and the output is a discrete digital signal;

[0010] The discrete digital signal is piecewise fitted to obtain a continuous piecewise function signal with respect to the change in transmittance, and the gradient of the continuous piecewise function with respect to the change in transmittance is solved.

[0011] The gradient change function signal is obtained by performing a piecewise gradient weighted solution on both sides of the gradient singularity point of a continuous piecewise function.

[0012] Based on the continuous piecewise function signal of light transmittance change, the gradient change function signal, and the corresponding preset threshold, the loss of grout in the tunnel excavation of the part to be detected is monitored.

[0013] Optionally, the step of acquiring the transmittance change in the area to be detected and converting the acquired transmittance change into an electrical analog signal specifically includes:

[0014] A transmittance sensing module is set at the part to be detected. The transmittance sensing module is used to convert the transmittance change in the detected part into an electrical analog signal. The transmittance sensing module includes at least one set of transmittance sensing units. Each set of transmittance sensing units includes two transmittance sensors arranged orthogonally in a plane. The transmittance sensors are used to detect the transmittance change in the orthogonal direction of their respective planes.

[0015] Furthermore, the spatial arrangement of the multiple sets of transmittance sensing units can be linear, clustered, or planar.

[0016] Optionally, the step of performing piecewise fitting on the discrete digital signal to obtain a continuous piecewise function signal with respect to the change in transmittance, and solving for the gradient of the continuous piecewise function with respect to the change in transmittance, specifically includes:

[0017] The discrete digital signal is segmented, and each segment is fitted to obtain a continuous piecewise function signal relating to the transmittance variation.

[0018] The gradient of the continuous piecewise function that yields the change in transmittance is calculated, and the area in the two orthogonal directions of each continuous piecewise function is obtained.

[0019] Furthermore, the piecewise function fitted for each segment can be expressed as:

[0020]

[0021] In equation (1) f n (x) is the fitting function for the nth segment of transmittance variation along a certain orthogonal direction, g n (y) is the nth segment fitting function of transmittance change in another orthogonal direction, where x and y are the time parameters in the two orthogonal directions, and f n (x) and g n(y) The start and end times and running times of both are consistent, F n (x,y) is a combined characterization parameter of transmittance in the nth segment of the fitted function signal;

[0022] Specifically, the gradient of the continuous piecewise function representing the change in transmittance is calculated as follows:

[0023] In equation (2), Let be a basis vector in a certain orthogonal direction. Let be a basis vector in another orthogonal direction;

[0024] Specifically, the area under the gradient of each continuous piecewise function in the two orthogonal directions is obtained as follows:

[0025] In equation (3), D is the plane formed by two orthogonal directions, and M is the area in the two orthogonal directions in the gradient solution of each continuous piecewise function.

[0026] Optionally, the discrete digital signal is fitted using polynomial fitting, and the correlation coefficient R after fitting is... 2 >0.8.

[0027] Optionally, the step of obtaining the gradient change function signal by performing piecewise gradient weighted solving on both sides of the gradient singularity point of the continuous piecewise function specifically includes:

[0028] For the gradient singularities of the continuous piecewise function that occur during the piecewise fitting process, the gradient change function signal is obtained by weighted solving of the gradients on both sides. Assuming that the gradient singularity point is F(x0,y0), the weighted average of the gradient limits on both sides of the gradient singularity point is taken. The weighted average is determined as follows:

[0029]

[0030] Where a is the weighting coefficient of the left gradient limit of the gradient singular point (x0, y0), b is the weighting coefficient of the right gradient limit of the gradient singular point (x0, y0), and a+b=1.

[0031] Furthermore, the monitoring of grout loss in the tunnel excavation site based on the continuous piecewise function signal of transmittance change, the gradient change function signal, and the corresponding preset threshold specifically includes:

[0032] Obtain the area in two orthogonal directions and the weighted average of the gradient limits on both sides of the gradient singularity point in the gradient change function signal during gradient solution for each continuous piecewise function signal;

[0033] The first statistical number of areas in two orthogonal directions that are greater than each preset area threshold during gradient calculation of a continuous piecewise function signal.

[0034] The second statistical number is that the weighted average of the gradient limits on both sides of all gradient singularities in the statistical gradient change function signal is greater than the corresponding preset weighted average threshold.

[0035] Based on the first and second statistical data and the preset warning level, the loss of grout in the tunnel excavation of the area to be tested is monitored.

[0036] Furthermore, the monitoring of grout loss in the tunnel excavation section to be inspected, based on the first statistical quantity, the second statistical quantity, and the preset warning level, specifically includes:

[0037] A database is pre-established to correspond to the tunnel grouting type, the type of grout used or injected during the grouting process, the first statistical quantity, the second statistical quantity, and the preset early warning level of the part to be inspected.

[0038] Obtain the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, and the current second statistical quantity;

[0039] Based on the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, the current second statistical quantity, and the corresponding relationship database, the corresponding early warning level is determined.

[0040] A second aspect of the present invention provides a tunnel grouting slurry loss monitoring system, comprising:

[0041] The system comprises a transmittance sensing module, a data processing module, and a monitoring module, which are sequentially connected in communication. The transmittance sensing module acquires the transmittance changes in the area to be detected and converts these changes into an analog electrical signal. The data processing module digitizes the converted analog signal, outputting a discrete digital signal. It then performs piecewise fitting on the discrete digital signal to obtain a continuous piecewise function signal relating to the transmittance changes, and solves for the gradient of this continuous piecewise function. Finally, it performs a weighted solution of the gradients on both sides of the gradient singularities of the continuous piecewise function to obtain a gradient change function signal. The monitoring module monitors the loss of grout during tunnel excavation at the area to be detected based on the continuous piecewise function signal of transmittance changes, the gradient change function signal, and a corresponding preset threshold.

[0042] The technical solution adopted in this invention has the following technical effects:

[0043] 1. The present invention obtains the transmittance change in the part to be detected, and processes it to obtain a continuous piecewise function signal and a gradient change function signal regarding the transmittance change; based on the continuous piecewise function signal, the gradient change function signal and the corresponding preset threshold, the loss of grout in tunnel excavation at the part to be detected is monitored, effectively solving the problem of low reliability and accuracy of grout loss monitoring in tunnel excavation caused by existing technology, and effectively improving the reliability and accuracy of grout loss monitoring in tunnel excavation.

[0044] 2. The transmittance sensing module in the technical solution of the present invention includes at least one set of transmittance sensing units. Each set of transmittance sensing units includes two transmittance sensors arranged orthogonally in a plane. The transmittance sensors are used to detect the transmittance changes in the orthogonal direction of their respective planes, which further improves the reliability of monitoring the loss of grout during tunnel excavation.

[0045] 3. The technical solution of this invention obtains the tunnel grouting type corresponding to the current location to be inspected, the type of grout used or injected in the grouting process corresponding to the current location to be inspected, the current first statistical quantity, and the current second statistical quantity; based on the tunnel grouting type corresponding to the current location to be inspected, the type of grout used or injected in the grouting process corresponding to the current location to be inspected, the current first statistical quantity, the current second statistical quantity, and the corresponding relationship database, the corresponding early warning level is determined; through quantitative monitoring of grout loss, the obtained data is processed and analyzed, and feedback is given to on-site workers, which can effectively avoid grout material loss and adjust relevant engineering measures, and effectively reduce the safety risks of on-site workers.

[0046] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating the method of Embodiment 1 in the present invention;

[0049] Figure 2 This is a flowchart illustrating step S3 in the method of Embodiment 1 of the present invention;

[0050] Figure 3This is a flowchart illustrating step S5 in the method of Embodiment 1 of the present invention;

[0051] Figure 4 This is a flowchart illustrating step S53 in the method of Embodiment 1 of the present invention;

[0052] Figure 5 This is a schematic diagram of the system structure in Embodiment 2 of the present invention. Detailed Implementation

[0053] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the invention. To simplify the disclosure of the invention, components and arrangements of specific examples are described below. Furthermore, reference numerals and / or letters may be repeated in different examples. This repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. It should be noted that the components illustrated in the drawings are not necessarily drawn to scale. Descriptions of well-known components, processing techniques, and processes are omitted in this invention to avoid unnecessarily limiting the invention.

[0054] Example 1

[0055] like Figure 1 As shown, the present invention provides a method for monitoring the loss of grout during tunnel excavation, comprising:

[0056] S1, acquire the transmittance change in the area to be detected, and convert the acquired transmittance change into an electrical analog signal;

[0057] S2 performs digital processing on the converted analog signal, and outputs a discrete digital signal.

[0058] S3, perform piecewise fitting on the discrete digital signal to obtain a continuous piecewise function signal with respect to the change in transmittance, and solve for the gradient of the continuous piecewise function with respect to the change in transmittance.

[0059] S4, the gradient change function signal is obtained by solving the gradient weighted solution on both sides of the gradient singularity point of the continuous piecewise function;

[0060] S5 monitors the loss of grout in the tunnel excavation at the detection site based on the continuous piecewise function signal of light transmittance change, the gradient change function signal, and the corresponding preset threshold.

[0061] In step S1, the changes in transmittance in the area to be detected are obtained, and the obtained changes in transmittance are converted into an electrical analog signal, specifically as follows:

[0062] A transmittance sensing module is installed at the location to be monitored (the installation location can be selected in the water body in the lower part of the tunnel or other locations requiring monitoring). Before use, the transmittance sensing module needs to be set to the initial value of the original water environment in the tunnel as a reference for subsequent transmittance changes. The transmittance sensing module is used to convert the transmittance changes in the monitored location into an electrical analog signal, and the electrical signal output by the transmittance sensing module can be processed into a discrete digital signal by the data processing module. The transmittance sensing module contains at least one set of transmittance sensing units (when there are multiple sets of transmittance sensing units, the average transmittance of multiple sets of transmittance sensing units can be calculated). Each set of transmittance sensing units includes two transmittance sensors arranged orthogonally in a plane. The transmittance sensors are used to detect the transmittance changes in the orthogonal direction of their respective planes. When setting multiple sets of transmittance sensing units, the spatial arrangement of the multiple sets of transmittance sensing units can be linear, clustered, surface-arranged, or arranged according to the monitoring needs inside the tunnel.

[0063] In step S2, the analog signal emitted by the transmittance sensing module can be digitally processed and output as a discrete digital signal (two discrete digital signals about transmittance in two corresponding orthogonal directions emitted by two transmittance sensors arranged in a plane). Specifically, during the signal discretization process, the analog signal can be output as a digital signal each time using the same time interval as the discretization distance. The discretization distance can be preset or adjusted according to the needs of the site.

[0064] Among them, such as Figure 2 As shown, step S3 specifically includes:

[0065] S31: The discrete digital signal is segmented, and each segment is fitted to obtain a continuous piecewise function signal relating to the transmittance variation.

[0066] S32, perform gradient calculation on the continuous piecewise function that yields the change in transmittance, and obtain the area in the two orthogonal directions in the gradient calculation of each continuous piecewise function.

[0067] In step S31, the digital signal is segmented. Using the same time interval as the discrete step size, it can be divided into n discrete signal segments. Each segment is fitted, and the segmented fitting of the discrete digital signal yields a continuous piecewise function signal regarding the change in transmittance. The piecewise function after fitting each segment can be expressed as:

[0068]

[0069] In equation (1), f n(x) is the nth segment fitting function of transmittance variation along a certain orthogonal direction (i.e., the transmittance after fitting the nth segment along a certain orthogonal direction, a piecewise function of transmittance after being collected and converted into a discrete digital signal by one of the transmittance sensors in each group of transmittance sensing units), g n (y) is the nth segment fitting function of transmittance change in another orthogonal direction (i.e., the transmittance after fitting the nth segment in another orthogonal direction, which is the piecewise function of transmittance after fitting the discrete digital signal collected and converted by another transmittance sensor in each group of transmittance sensing units), x and y are the time parameters in the two orthogonal directions, and f n (x) and g n (y) The start and end times and running times of both are consistent, F n (x, y) represents the combined transmittance parameters in the nth segment of the fitted function signal. In the process of obtaining a continuous piecewise function signal regarding transmittance variation by piecewise fitting of a discrete digital signal, the fitting method for the discrete signal can be polynomial fitting, and the correlation coefficient after fitting needs to satisfy R0. 2 >0.8.

[0070] In step S32, the gradient calculation for the continuous piecewise function of transmittance change is specifically performed as follows:

[0071] In equation (2), Let be a basis vector in a certain orthogonal direction. Let be a basis vector in another orthogonal direction;

[0072] Specifically, the area under the gradient of each continuous piecewise function in the two orthogonal directions is obtained as follows:

[0073] In equation (3), D is the plane formed by two orthogonal directions, and M is the area in the two orthogonal directions in the gradient solution of each continuous piecewise function.

[0074] Specifically, in step S4, the gradient change function signal is obtained by performing a piecewise gradient weighted solution on both sides of the gradient singularity point of the continuous piecewise function:

[0075] For the gradient singularities of the continuous piecewise function that occur during the piecewise fitting process, the gradient change function signal is obtained by weighted solving of the gradients on both sides. Assuming that the gradient singularity point is F(x0,y0), the weighted average of the gradient limits on both sides of the gradient singularity point is taken. The weighted average is determined as follows:

[0076]

[0077] Where 'a' is the weighting coefficient of the left gradient limit of the gradient singularity point (x0, y0), and 'b' is the weighting coefficient of the right gradient limit of the gradient singularity point (x0, y0), and a + b = 1. That is, the default values ​​for a and b can both be 0.5. These can be adjusted according to on-site needs, provided that 0 < a ≤ 1, 0 < b ≤ 1, and a + b = 1. The values ​​of a and b can also be dynamically determined by the on-site operating conditions.

[0078] Among them, such as Figure 3 As shown, step S5 specifically includes:

[0079] S51, obtain the area in two orthogonal directions and the weighted average of the gradient limits on both sides of the gradient singular point in the gradient change function signal during gradient solution of each continuous piecewise function signal.

[0080] S52, the first statistical number of areas in two orthogonal directions that are greater than each preset area threshold during gradient calculation of continuous piecewise function signals;

[0081] S53, The second statistical number of gradient limits on both sides of all gradient singularities in the statistical gradient change function signal that are greater than the corresponding preset weighted average threshold.

[0082] S54. Based on the first statistical quantity, the second statistical quantity, and the preset early warning level, monitor the loss of grout in the tunnel excavation of the part to be tested.

[0083] The preset area thresholds correspond to each segment of the continuous piecewise function signal and can be flexibly set based on the transmittance of the slurry without loss of water. This allows for adjustments based on on-site engineering requirements and the instrument's sensitivity to the water. Similarly, the preset weighted average thresholds correspond to the gradient singularities of each segment of the continuous piecewise function signal and can be flexibly set based on the transmittance of the slurry without loss of water. This allows for adjustments based on on-site engineering requirements and the instrument's sensitivity to the water.

[0084] Furthermore, such as Figure 4 As shown, step S54 specifically includes:

[0085] S541, a database is established in advance to correspond to the tunnel grouting type, the type of grout used or injected during the grouting process of the part to be inspected, the first statistical quantity, the second statistical quantity and the preset warning level.

[0086] S542, obtain the tunnel grouting type corresponding to the current part to be inspected, the type of grout used or injected in the grouting process corresponding to the current part to be inspected, the current first statistical quantity, and the current second statistical quantity;

[0087] S543. Based on the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, the current second statistical quantity, and the corresponding relationship database, determine the corresponding early warning level.

[0088] In step S541, the corresponding relationship database pre-stores the correspondence between the tunnel grouting type of the part to be inspected, the type of grout used or injected in the grouting process of the part to be inspected, the first statistical quantity, the second statistical quantity and the preset warning level. That is, the corresponding warning level can be determined by the tunnel grouting type of the part to be inspected, the type of grout used or injected in the grouting process of the part to be inspected, the first statistical quantity and the second statistical quantity.

[0089] Specifically, the tunnel grouting involved in this invention refers to grouting that can form a suspension / emulsion in groundwater, or grouting that can reduce the light transmittance of the original groundwater when it diffuses in water. Types of tunnel grouting include: forward / backward curtain grouting, advanced support grouting, localized water / mud inrush grouting, and other tunnel grouting methods. The grouts used / injected during the grouting process include: cement single-component grout, CS two-component grout, cement-based grout, mineral-based grout, solid waste-based grout, acrylamide-based chemical grout, polyurethane-based chemical grout, lignin-based chemical grout, epoxy resin-based chemical grout, unsaturated ester-based chemical grout, and other grout types.

[0090] In step S542, the tunnel grouting type corresponding to the current location to be detected and the type of grout used or injected in the grouting process corresponding to the current location to be detected can be obtained by the user selecting the input method on site. The current first statistical quantity and the current second statistical quantity can be obtained by calculating, comparing and statistically analyzing the monitoring information.

[0091] In step S543, the corresponding early warning level is determined based on the tunnel grouting type corresponding to the current location to be inspected, the type of grout used or injected in the grouting process corresponding to the current location to be inspected, the current first statistical quantity, the current second statistical quantity, and the corresponding relational database.

[0092] Specifically, the higher the current first or second statistical quantity, the higher the corresponding warning level. Warning levels can be divided into three levels from low to high: 0, 1, and 2 (for example, other quantity levels can be used). For instance, if the current first statistical quantity is less than the first preset statistical threshold and the current second statistical quantity is less than the second preset statistical threshold, the corresponding warning level is 0; if the current first statistical quantity is less than the third preset statistical threshold and the current second statistical quantity is less than the fourth preset statistical threshold, the corresponding warning level is 1; if the current first statistical quantity is not less than the third preset statistical threshold and the current second statistical quantity is not less than the fourth preset statistical threshold, the corresponding warning level is 2. Here, the first preset statistical threshold is less than the third preset statistical threshold, and the second preset statistical threshold is less than the fourth preset statistical threshold. Furthermore, the first preset statistical threshold can be equal to or not equal to (greater than) the second preset statistical threshold, and the specific situation can be flexibly determined based on the on-site conditions. Similarly, the third preset statistical threshold can be equal to or not equal to (greater than) the fourth preset statistical threshold, and the specific situation can be flexibly determined based on the on-site conditions.

[0093] It should be noted that the tunnel grouting method involved in this invention involves a certain amount of grout flowing out or seeping out along channels such as pipes / fissures in the rock mass during the grouting process. This also includes the grout flowing out or seeping out along channels such as pipes / fissures in the rock mass during the water pressure test, hydrological tracing test, and hydrochemical test before grouting.

[0094] The present invention acquires the transmittance change in the area to be detected and processes it to obtain a continuous piecewise function signal and a gradient change function signal related to the transmittance change. Based on the continuous piecewise function signal, the gradient change function signal, and the corresponding preset threshold, the loss of grout in tunnel excavation at the area to be detected is monitored. This effectively solves the problem of low reliability and accuracy of grout loss monitoring in tunnel excavation caused by existing technologies, and effectively improves the reliability and accuracy of grout loss monitoring in tunnel excavation.

[0095] The transmittance sensing module in the technical solution of the present invention includes at least one set of transmittance sensing units. Each set of transmittance sensing units includes two transmittance sensors arranged orthogonally in a plane. The transmittance sensors are used to detect the transmittance changes in the orthogonal direction of their respective planes, which further improves the reliability of monitoring the loss of grout during tunnel excavation.

[0096] The technical solution of this invention obtains the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, and the current second statistical quantity; based on the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, the current second statistical quantity, and the corresponding relationship database, the corresponding early warning level is determined; through quantitative monitoring of grout loss, the obtained data is processed and analyzed, and feedback is given to on-site workers, which can effectively avoid grout material loss and adjust relevant engineering measures, and effectively reduce the safety risks of on-site workers.

[0097] Example 2

[0098] like Figure 5 As shown, the present invention also provides a tunnel grouting slurry loss monitoring system, comprising:

[0099] The system consists of a transmittance sensing module 1, a data processing module 2, and a monitoring module 3, which are connected in sequence. The transmittance sensing module 1 acquires the transmittance changes in the area to be detected and converts these changes into an analog electrical signal. The data processing module 2 digitizes the converted analog signal, outputting a discrete digital signal. It then performs piecewise fitting on the discrete digital signal to obtain a continuous piecewise function signal relating to the transmittance changes, and solves for the gradient of this continuous piecewise function. Finally, it performs a weighted solution of the gradients of the singular points of the continuous piecewise function to obtain a gradient change function signal. The monitoring module 3 monitors the loss of grout during tunnel excavation at the area to be detected based on the continuous piecewise function signal of transmittance changes, the gradient change function signal, and the corresponding preset threshold.

[0100] A transmittance sensing module 1 is installed at the area to be detected. The transmittance sensing module 1 is used to convert the transmittance changes in the detected area into an electrical analog signal and send the electrical analog signal to the data processing module 2. The transmittance sensing module 1 includes at least one set of transmittance sensing units 11. Each set of transmittance sensing units 11 includes two transmittance sensors 111 arranged orthogonally in a plane. The transmittance sensors 111 are used to detect the transmittance changes in the orthogonal direction of their respective planes.

[0101] The spatial arrangement of multiple sets of transmittance sensing units 11 can be linear, clustered, or planar, and can also be arranged according to the monitoring needs inside the tunnel.

[0102] The working principle of the transmittance sensing module 1 is as follows: the transmittance sensor 111 monitors the changes in transmittance in the water body and converts the changes in transmittance into an analog signal, which is then transmitted to the data processing module 2. Since the tunnel is mostly dark or has no light during the tunnel excavation process, the sensor can be equipped with an adjustable light source.

[0103] The analog electrical signal converted by the transmittance sensing module 1 is effectively compatible with the data processing module 2. The analog signal is continuous and has a certain threshold, which can ensure that the transmittance sensing module 1 and the data processing module 2 will not be affected by the overload of the analog signal, thus ensuring the long-term normal operation of the equipment.

[0104] Preferably, the light transmittance sensing module 1 can use a waterproof and pressure-resistant protective shell; the electrical signal output by the light transmittance sensing module 1 can be processed into a discrete digital signal by the data processing module.

[0105] Furthermore, during the signal discretization process, the data processing module 2 can output the analog signal as a digital signal each time using the same time interval as the discretization distance; the discretization distance can be adjusted according to the on-site requirements.

[0106] Furthermore, the monitoring module 3 can transmit monitoring information to the monitoring personnel via wired or wireless transmission modules, which can effectively prevent the loss of slurry materials and adjust relevant engineering measures, and effectively reduce the safety risks of on-site workers.

[0107] The present invention acquires the transmittance change in the area to be detected and processes it to obtain a continuous piecewise function signal and a gradient change function signal related to the transmittance change. Based on the continuous piecewise function signal, the gradient change function signal, and the corresponding preset threshold, the loss of grout in tunnel excavation at the area to be detected is monitored. This effectively solves the problem of low reliability and accuracy of grout loss monitoring in tunnel excavation caused by existing technologies, and effectively improves the reliability and accuracy of grout loss monitoring in tunnel excavation.

[0108] The transmittance sensing module in the technical solution of the present invention includes at least one set of transmittance sensing units. Each set of transmittance sensing units includes two transmittance sensors arranged orthogonally in a plane. The transmittance sensors are used to detect the transmittance changes in the orthogonal direction of their respective planes, which further improves the reliability of monitoring the loss of grout during tunnel excavation.

[0109] The technical solution of this invention obtains the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, and the current second statistical quantity; based on the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, the current second statistical quantity, and the corresponding relationship database, the corresponding early warning level is determined; through quantitative monitoring of grout loss, the obtained data is processed and analyzed, and feedback is given to on-site workers, which can effectively avoid grout material loss and adjust relevant engineering measures, and effectively reduce the safety risks of on-site workers.

[0110] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method for monitoring grout loss during tunnel excavation, characterized in that, include: The transmittance changes in the area to be tested are obtained, and the obtained transmittance changes are converted into an electrical analog signal; The converted analog signal is digitized, and the output is a discrete digital signal; The discrete digital signal is piecewise fitted to obtain a continuous piecewise function signal with respect to the change in transmittance, and the gradient of the continuous piecewise function with respect to the change in transmittance is solved. The gradient change function signal is obtained by performing a piecewise gradient weighted solution on both sides of the gradient singularity point of a continuous piecewise function. Based on the continuous piecewise function signal of light transmittance change, the gradient change function signal, and the corresponding preset threshold, the loss of grout in the tunnel excavation of the part to be detected is monitored.

2. The method for monitoring grout loss during tunnel excavation according to claim 1, characterized in that, The step of acquiring the transmittance change in the area to be detected and converting the acquired transmittance change into an electrical analog signal specifically includes: A transmittance sensing module is set at the part to be detected. The transmittance sensing module is used to convert the transmittance change in the detected part into an electrical analog signal. The transmittance sensing module includes at least one set of transmittance sensing units. Each set of transmittance sensing units includes two transmittance sensors arranged orthogonally in a plane. The transmittance sensors are used to detect the transmittance change in the orthogonal direction of their respective planes.

3. The method for monitoring grout loss during tunnel excavation according to claim 2, characterized in that, The spatial arrangement of the multiple sets of transmittance sensing units can be linear, clustered, or planar.

4. The method for monitoring grout loss during tunnel excavation according to claim 2, characterized in that, The step of performing piecewise fitting on the discrete digital signal to obtain a continuous piecewise function signal with respect to the change in transmittance, and then solving for the gradient of the continuous piecewise function with respect to the change in transmittance, specifically includes: The discrete digital signal is segmented, and each segment is fitted to obtain a continuous piecewise function signal with respect to the change in transmittance. The gradient of the continuous piecewise function that yields the change in transmittance is calculated, and the area in the two orthogonal directions of each continuous piecewise function is obtained.

5. The method for monitoring grout loss during tunnel excavation according to claim 4, characterized in that, The piecewise function after fitting each segment can be expressed as: In equation (1) f n (x) is the fitting function for the nth segment of transmittance variation along a certain orthogonal direction, g n (y) is the nth segment fitting function of transmittance change in another orthogonal direction, where x and y are the time parameters in the two orthogonal directions, and f n (x) and g n (y) The start and end times and running times of both are consistent, F n (x,y) is a combined characterization parameter of transmittance in the nth segment of the fitted function signal; Specifically, the gradient of the continuous piecewise function representing the change in transmittance is calculated as follows: In equation (2), Let be a basis vector in a certain orthogonal direction. Let be a basis vector in another orthogonal direction; Specifically, the area under the gradient of each continuous piecewise function in the two orthogonal directions is obtained as follows: In equation (3), D is the plane formed by two orthogonal directions, and M is the area in the two orthogonal directions in the gradient solution of each continuous piecewise function.

6. The method for monitoring grout loss during tunnel excavation according to claim 4, characterized in that, The discrete digital signal is fitted using polynomial fitting, and the correlation coefficient R after fitting is... 2 >0.

8.

7. The method for monitoring grout loss during tunnel excavation according to claim 5, characterized in that, The step of obtaining the gradient change function signal by performing a piecewise gradient weighted solution on both sides of the gradient singularity point of the continuous piecewise function specifically includes: For the gradient singularities of the continuous piecewise function that occur during the piecewise fitting process, the gradient change function signal is obtained by weighted solving of the gradients on both sides. Assuming that the gradient singularity point is F(x0,y0), the weighted average of the gradient limits on both sides of the gradient singularity point is taken. The weighted average is determined as follows: Where a is the weighting coefficient of the left gradient limit of the gradient singular point (x0, y0), b is the weighting coefficient of the right gradient limit of the gradient singular point (x0, y0), and a+b=1.

8. The method for monitoring grout loss during tunnel excavation according to claim 7, characterized in that, The monitoring of grout loss in the tunnel excavation section based on the continuous piecewise function signal of transmittance change, the gradient change function signal, and the corresponding preset threshold specifically includes: Obtain the area in two orthogonal directions and the weighted average of the gradient limits on both sides of the gradient singularity point in the gradient change function signal during gradient solution for each continuous piecewise function signal; The first statistical number of areas in two orthogonal directions that are greater than each preset area threshold during gradient calculation of a continuous piecewise function signal. The second statistical number is that the weighted average of the gradient limits on both sides of all gradient singular points in the statistical gradient change function signal is greater than the corresponding preset weighted average threshold. Based on the first and second statistical data and the preset warning level, the loss of grout in the tunnel excavation of the part to be tested is monitored.

9. A method for monitoring grout loss during tunnel excavation according to claim 8, characterized in that, The monitoring of grout loss in the tunnel excavation section to be inspected, based on the first statistical quantity, the second statistical quantity, and the preset early warning level, specifically includes: A database is pre-established to correspond to the tunnel grouting type, the type of grout used or injected during the grouting process, the first statistical quantity, the second statistical quantity, and the preset early warning level of the part to be inspected. Obtain the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, and the current second statistical quantity; Based on the tunnel grouting type corresponding to the current inspection location, the type of grout used or injected in the grouting process corresponding to the current inspection location, the current first statistical quantity, the current second statistical quantity, and the corresponding relationship database, the corresponding early warning level is determined.

10. A grout loss monitoring system for tunnel excavation, characterized in that, include: The system comprises a transmittance sensing module, a data processing module, and a monitoring module, which are sequentially connected in communication. The transmittance sensing module acquires the transmittance changes in the area to be detected and converts these changes into an analog electrical signal. The data processing module digitizes the converted analog signal, outputting a discrete digital signal. It then performs piecewise fitting on the discrete digital signal to obtain a continuous piecewise function signal relating to the transmittance changes, and solves for the gradient of this continuous piecewise function. Finally, it performs a weighted solution of the gradients on both sides of the gradient singularities of the continuous piecewise function to obtain a gradient change function signal. The monitoring module monitors the loss of grout during tunnel excavation at the area to be detected based on the continuous piecewise function signal of transmittance changes, the gradient change function signal, and a corresponding preset threshold.

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