Early warning method and early warning device for shield construction overexcavation amount

Abstract

The invention discloses a shield construction overexcavation amount early warning method and early warning device, belongs to the technical field of tunnel construction, and aims to overcome the defects that in the prior art, overexcavation amount calculation is inaccurate, parameters are difficult to obtain due to dependence, early warning is not associated with actual risks, and man-machine interaction is insufficient. According to the method, shield tunneling ring footage is used as a calculation unit, the theoretical slag discharge amount is calculated by introducing a soil body loose coefficient, the actually measured slag discharge amount is obtained by adopting contour collection and belt speed monitoring, and the actual over-excavation amount is obtained by deducting the injection amount; and based on equivalent stratum loss or a settling tank theory, the over-excavation amount is converted into the maximum settlement amount of the earth surface, and a two-stage grading early warning mechanism is established. The device comprises a data acquisition module, a data communication module and a man-machine interaction module, and realizes accurate data acquisition, stable transmission and intelligent early warning. According to the method, the over-excavation amount calculation precision is improved, the relevance between early warning and engineering risks is enhanced, man-machine interaction is convenient, and the shield construction safety management and control level can be remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel construction, in particular to a shield construction overbreak amount early warning method and early warning device. BACKGROUND

[0002] In the process of shield tunnel construction, in order to reduce the frictional resistance between the soil and the shield shell, a design of a cutter head diameter larger than the shield body is usually adopted for moderate overbreak; and when small curvature tunneling is performed, unilateral overbreak is also needed to provide convenience for shield posture adjustment, which will inevitably lead to stratum loss. In addition, the shield tunneling speed is slow, and the stratum stress release caused by the cutter head overbreak will cause the surrounding soil to rebound and deform, further causing potential overbreak. The existence of overbreak will destroy the original stress balance of the soil, cause the soil above to move into the tunnel, and cause ground subsidence or even collapse, which not only requires additional investment in materials and labor costs for grouting reinforcement, but also may delay the construction period; at the same time, the cavity formed behind the segment by overbreak will cause the supporting structure to bear uneven load, inducing segment cracking, leakage and other hidden dangers, and also causing the shield posture to lose control when tunneling in loose soil, seriously affecting the quality of tunnel forming. Therefore, precise monitoring and control of overbreak amount is the key to ensuring the safety of shield construction and improving the overall quality of the project.

[0003] The core calculation logic of shield overbreak amount is the difference between the actual excavation amount and the design theoretical amount, and the design theoretical amount can be calculated by the volume of the soil corresponding to the design tunnel diameter. The acquisition of the actual excavation amount and the overbreak amount early warning become technical difficulties, and the existing technology mainly has the following problems: First, the theoretical calculation method is limited in application scenarios. Some patent with publication number CN114386264A discloses a shield machine overbreak amount calculation method, which calculates the overbreak amount by establishing a posture model and using geometric relationships, but this method is only applicable to shield turning and advancing scenarios and cannot cover regular construction conditions such as straight tunneling, which lacks universality.

[0004] Second, the actual measurement method has the problems of calculation deviation or parameter dependence. The actual measurement method mainly includes weighing method and machine vision method: the weighing method such as the patent with publication number CN119884562A discloses a composite stratum shield construction excavation amount calculation method and overbreak and underbreak real-time monitoring method, which needs to calculate the actual excavation volume in combination with stratum cross-sectional area proportion, soil density and other parameters, but these stratum physical and mechanical parameters are difficult to accurately obtain in the engineering site, leading to the difficulty in popularization of the method; the machine vision method such as the patent with publication number CN120747138A discloses a shield spoil three-dimensional point cloud segmentation and volume calculation method based on deep learning, which can directly measure the spoil volume on the belt conveyor, but the measurement result contains components such as bulk piled soil and spoil modifier, and cannot directly distinguish the true overbreak amount.

[0005] Thirdly, the existing early warning technology is not associated with engineering actual risks and lacks interaction. For example, the patent with publication number CN114485391A discloses a shield slag soil anti-over-discharge early warning method based on three-dimensional laser scanning technology. After obtaining the actual discharge volume through three-dimensional laser scanning, the method only compares it with the theoretical volume range to realize early warning, but does not consider the interference of water, foam, bentonite and other modifiers injected in shield construction on the discharge measurement, resulting in inaccurate overbreak calculation. At the same time, this kind of technology takes an arbitrary over-discharge early warning period as a comparison unit, and the early warning is not strong in pertinence, and the overbreak is not directly associated with core engineering risks such as ground surface settlement. Only through volume threshold judgment, the actual impact of overbreak on construction safety cannot be intuitively reflected. In addition, the existing technology generally lacks an efficient human-computer interaction mechanism, and the shield driver cannot obtain accurate overbreak early warning information in real time, cannot adjust the construction parameters in time, and is easy to cause the expansion of the overbreak range. SUMMARY

[0006] The present application provides a shield construction overbreak early warning method and device, which solves the problems of inaccurate overbreak calculation, engineering inapplicability of the calculation method, and non-association of the early warning logic with actual construction risks in the prior art.

[0007] The technical solution of the present application is as follows: A shield construction overbreak early warning method takes a shield tunneling ring footage as a basic calculation unit, and includes the following steps: S1, calculating the theoretical discharge volume V of a shield tunneling ring c : Based on the designed excavation volume of a shield tunneling ring, the volume expansion effect of the excavated soil body is corrected by introducing a loose coefficient to obtain the theoretical discharge volume V c ; S2, obtaining the measured discharge volume V of a shield tunneling ring m : The surface profile information of the slag soil on the shield belt and the running speed of the shield belt are collected, the tunneling start and end time of the current ring footage is extracted, and the measured discharge volume V of a shield tunneling ring is calculated m ; S3, calculating the actual soil overbreak volume V of a shield tunneling ring o : The injection amount of water, foam and bentonite in shield tunneling is included in the overbreak calculation, and the actual soil overbreak volume V of a shield tunneling ring is obtained o ; S4, calculating the maximum ground surface settlement S caused by overbreak max : According to the equivalent stratum loss theory or the settlement tank theory, the calculated overbreak volume V o is converted into the corresponding maximum ground surface settlement S max ; S5, graded early warning judgment and signal output: the ground surface settlement control value S is set in advance cWhen the maximum ground settlement S max is greater than 85% of the ground settlement control value S c , a yellow warning signal is issued; when the maximum ground settlement S max is greater than the ground settlement control value S c , a red warning signal is issued.

[0008] In S1, the shield cutterhead excavation radius R c and the ring footage B obtained by self-sensing are extracted, the design excavation volume of a shield tunneling ring is calculated, the excavation volume is multiplied by the loose coefficient, and then the theoretical spoil quantity of the current ring of shield tunneling is calculated, and the calculation formula is as follows: In the formula, V c is the theoretical spoil quantity of a shield tunneling ring; R c is the tunnel excavation radius; B is the ring footage length; and K is the loose coefficient.

[0009] In S2, the surface profile information of the spoil on the belt is collected by the profile sensor above the shield belt, and the belt running speed is obtained by the rotational speed sensor at the bottom of the shield belt, and the measured spoil quantity calculation formula is as follows: In the formula, V m is the measured spoil quantity of a shield tunneling ring; A is the spoil profile cross-sectional area; v is the belt running speed; t0 is the start time of the current ring of shield tunneling; t1 is the end time of the current ring of shield tunneling; and t2 is the time of the spoil from the cutterhead to the profile sensor detection position.

[0010] In S3, the actual soil overbreak calculation process is as follows: First, the injection quantity V i of water, foam, and bentonite is calculated, Then, the one-ring overbreak V o is calculated, When V , then V When V , then V In the formula, V i is the injection quantity of water, foam, and bentonite of a shield tunneling ring; V o is the actual soil overbreak of a shield tunneling ring; V w is the cumulative injection quantity of water of the current ring; V f is the cumulative injection quantity of foam of the current ring; and V b is the cumulative injection quantity of bentonite of the current ring.

[0011] In S4, according to the equivalent stratum loss theory, the maximum ground settlement is: In the formula: S max is the maximum ground settlement; B is the length of a ring; μ is the Poisson's ratio of the soil; H1 is the depth of the tunnel; and L is the length of the shield shell.

[0012] In S4, according to the settlement tank theory, the maximum ground settlement caused by overbreakage is: In the formula: B is the length of a ring; S max is the maximum ground settlement; i is the width coefficient of the settlement tank; H2 is the depth from the ground to the center of the tunnel; and Φ is the internal friction angle of the soil.

[0013] An early warning device applying the overbreakage early warning method for shield construction, comprising a data acquisition module, a data communication module and a man-machine interaction module; the data acquisition module is used for acquiring spoil volume related data and shield construction parameters; the data communication module uses a wireless or wired communication module to transmit various information data collected by the data acquisition module to the man-machine interaction module; the man-machine interaction module is used for receiving the data transmitted by the data communication module, completing the calculation of theoretical spoil volume V c , measured spoil volume V m , overbreakage V o and the maximum ground settlement S max , executing graded early warning judgment and outputting an early warning signal.

[0014] The spoil volume related data includes spoil contour and belt running speed, and the shield construction parameters include ring footage, current ring tunneling start and end time, foam injection amount, water injection amount and bentonite injection amount.

[0015] The man-machine interaction module comprises a data receiving submodule, a data processing and evaluation submodule, a visualization submodule and a system configuration submodule; the output end of the data receiving submodule is connected to the input end of the data processing and evaluation submodule; the output end of the data processing and evaluation submodule is connected to the input end of the visualization submodule; and the system configuration submodule is respectively connected to the data receiving submodule, the data processing and evaluation submodule and the visualization submodule.

[0016] The data receiving submodule is used for transmitting the received real-time monitoring data to the data processing and evaluation submodule; the data processing and evaluation submodule is built-in with the calculation program of the above early warning method, and is used for completing the calculation of theoretical spoil volume V c , measured spoil volume V m , overbreakage V o and the maximum ground settlement S maxThe calculation; simultaneously loading two-level early warning judgment logic, comparing with the maximum surface subsidence S max With the surface settlement control value S c The system generates early warning status information based on the relationship between the system and the data. The visualization submodule is used to display data charts such as real-time monitoring data, slag discharge statistics and early warning information, and system settings. The system configuration submodule is used to issue start and stop control commands and parameter configuration information to each submodule to realize the control of the operating status of each submodule.

[0017] The beneficial effects of this invention are: 1. Significantly improved accuracy in over-excavation calculation: The loosening coefficient is introduced to calculate the theoretical slag volume, eliminating the interference of loose soil on the actual over-excavation judgment; by incorporating the injection amount of amendments such as water, foam, and bentonite into the calculation model, the interference of amendments on slag volume measurement is effectively eliminated; at the same time, the combination of "contour acquisition + belt speed monitoring" is adopted to obtain the measured slag volume, avoiding the dependence of the weighing method on difficult-to-obtain parameters such as soil density, resulting in small calculation errors, which are far superior to existing technologies.

[0018] 2. Strong targeted early warning and risk correlation: Establishing a correlation model between over-excavation and surface settlement, the early warning logic is directly linked to the core risks of the project, rather than relying solely on volume thresholds, which can intuitively reflect the actual impact of over-excavation on construction safety; the two-level early warning mechanism combined with emergency operation suggestions provides construction personnel with a tiered management plan, effectively reducing the probability of accidents such as surface settlement and segment cracking.

[0019] 3. Convenient human-computer interaction, improving construction management efficiency: The system displays monitoring data, calculation results and early warning information in real time through a visual interface, making it easy for tunnel boring machine operators to quickly obtain key information; the system configuration sub-modules make it easy for construction personnel to adjust parameters according to working conditions, forming a closed-loop management of data collection, calculation, early warning and disposal, which significantly improves the level of intelligence in tunnel boring machine construction.

[0020] 4. Strong engineering applicability: Based on the tunnel boring machine's ring advance as the basic calculation unit, all required parameters are collected through the existing sensors of the tunnel boring machine or conventional industrial sensors, eliminating the need for additional complex equipment and reducing engineering application costs; parameters such as loosening coefficient and settlement control value can be flexibly configured according to stratum type and construction specifications, adapting to tunnel boring machine construction scenarios under different geological conditions. Attached Figure Description

[0021] 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, 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.

[0022] Figure 1 This is a flowchart of a method for early warning of over-excavation in shield tunneling construction according to the present invention; Figure 2 This is a schematic diagram of an over-excavation early warning device; Figure 3 This is a diagram of the human-machine interface for the over-excavation early warning device. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1, such as Figure 1 As shown, a method for early warning of over-excavation in shield tunneling uses the circumferential advance of the shield tunnel as the basic calculation unit. The circumferential advance refers to the distance the working face advances after the shield machine completes a complete mining or tunnel construction cycle. The method includes the following steps: S1, Calculate the theoretical muck removal volume V of one ring of shield tunneling. c Based on the design excavation volume of one ring of shield tunneling, a loosening coefficient is introduced to correct for the volume expansion effect of the soil after excavation, and the theoretical muck removal volume V is obtained. c Eliminate the interference of loose excavated soil on the judgment of actual over-excavation.

[0025] S2, obtain the measured amount of slag removed (V) during the first ring of shield tunneling. m The system collects information on the surface contour of the excavated soil on the tunnel boring machine (TBM) conveyor belt and the belt's operating speed. It then extracts the start and end times of the current ring advance and calculates the measured amount of excavated soil (V) for one ring of tunneling. m The system employs a combination of contour acquisition and speed monitoring to collect real-time data on the volume of excavated soil on the conveyor belt. By combining this data with the start and end times of the current ring advance, the actual amount of excavated soil in one ring can be accurately calculated, avoiding errors from a single measurement method and ensuring the real-time nature and relevance of the data.

[0026] S3, Calculate the actual over-excavation volume V of the soil during the first ring of shield tunneling. o The injection volumes of water, foam, and bentonite during shield tunneling are included in the over-excavation calculation to obtain the actual over-excavation volume V of the soil in one ring of shield tunneling. o The difference between the measured slag output and the theoretical slag output was corrected, eliminating the interference of the modifier on the slag output measurement.

[0027] S4, calculate the maximum surface settlement S caused by over-excavation. max Based on the equivalent formation loss theory or settlement trough theory, the calculated over-excavation volume V is...o Converted into the corresponding maximum surface subsidence S max Establish a direct correlation between over-excavation and settlement, transforming abstract over-excavation data into perceptible engineering risk indicators, and intuitively reflecting the actual impact of over-excavation on construction safety.

[0028] S5, Graded Early Warning Judgment and Signal Output: Pre-set surface subsidence control value S c When the maximum surface subsidence S max Greater than the surface settlement control value S c A yellow warning signal is issued when the surface subsidence reaches 85%; when the maximum surface subsidence S... max Greater than the surface settlement control value S c A red alert signal will be issued at the appropriate time. A yellow alert will prompt the tunnel boring machine operator to closely monitor the construction parameters, appropriately reduce the tunneling speed, adjust the proportion of soil amendment injection, and adjust the over-excavation amount of the tunnel boring machine, so as to restore the maximum surface settlement to the set range. A red alert will prompt the construction personnel to immediately check the cause of over-excavation and take emergency measures such as grouting reinforcement and adjusting the tunnel boring machine attitude.

[0029] The aforementioned early warning method acquires the over-excavation amount during shield tunneling construction in real time, calculates the surface settlement caused by the over-excavation amount, and then calculates the maximum surface settlement. By determining whether the maximum surface settlement caused by the over-excavation amount exceeds the early warning limit, the over-excavation amount early warning is achieved, which intuitively reflects the actual impact of over-excavation on construction safety.

[0030] Example 2, based on Example 1, provides a method for early warning of over-excavation in shield tunneling. In S1, the excavation radius R of the shield machine cutterhead is extracted. c Based on the advance length B obtained from its own sensors, the design excavation volume of one ring of the shield tunnel is calculated. Specifically, the tunnel excavation radius and advance length of one ring are obtained through the shield machine's built-in sensing system. The excavation volume is multiplied by a loosening coefficient to calculate the theoretical muck removal volume of the current ring. The loosening coefficient is determined based on the engineering geological survey report, similar engineering construction experience, or on-site soil tests. The calculation formula is as follows: In the formula, V c R represents the theoretical slag removal volume for one ring of shield tunneling; c B is the tunnel excavation radius; B is the length of one ring advance; K is the loosening coefficient. The loosening coefficient typically ranges from 1.05 to 1.35, with 1.2 to 1.35 for cohesive soil and 1.1 to 1.25 for sandy soil.

[0031] Furthermore, in S2, the contour information of the excavated soil surface on the tunnel boring machine (TBM) belt is collected by a contour sensor above the TBM belt, and the belt speed is obtained by a speed sensor at the bottom of the TBM belt. Specifically, a contour sensor is installed above the TBM belt to collect the three-dimensional contour information of the excavated soil surface in real time during belt operation. In this embodiment, a laser scanner is used as the contour sensor. The contour sensor scans the contour shape on the belt to obtain the cross-sectional area of ​​the excavated soil contour. A speed sensor is installed at the bottom of the belt to collect the belt speed in real time. The formula for calculating the measured excavated soil volume is as follows: In the formula, V m t0 represents the measured amount of excavated material during the tunnel boring machine's first ring; A represents the cross-sectional area of ​​the excavated material profile, obtained from the excavated material profile acquisition sensor; v represents the belt conveyor speed; t0 represents the start time of the current ring of tunnel boring machine excavation; t1 represents the end time of the current ring of tunnel boring machine excavation; and t2 represents the time it takes for the excavated material to travel from the cutterhead to the position detected by the profile sensor.

[0032] Furthermore, in S3, the actual over-excavation calculation process is as follows: First, calculate the injection volume V of water, foam, and bentonite. i , Then calculate the over-excavation volume V of the first ring. o , when At that time, when At that time, In the formula, V i V represents the total injection volume of water, foam, and bentonite in one ring of the tunnel boring machine; o V represents the actual over-excavation volume of soil during the tunnel boring machine's first ring excavation. w V represents the current cumulative injection volume of the circulating water; f V represents the cumulative injection volume of the current ring foam; b This represents the cumulative amount of bentonite injected into the current ring. After the soil loosens, voids will exist. Water, foam, and bentonite injected will enter these voids. When the injected amount is less than the change in soil volume before and after loosening, the actual over-excavation amount is calculated by ignoring the injected amount and directly subtracting the theoretical slag volume from the measured slag volume. When the injected amount is greater than the change in soil volume before and after loosening, the actual over-excavation amount is calculated by subtracting the injected amount and the volume of the soil before loosening from the measured slag volume.

[0033] When V o When V is positive, it indicates over-excavation; when V is positive, it indicates over-excavation. o When V is zero, it indicates no over-excavation; when V is zero, it indicates no over-excavation. o A negative value indicates that there is under-digging.

[0034] Furthermore, in S4, the over-excavation during shield tunneling causes the soil around the tunnel walls to move towards the tunnel center, and the displacement of points on the ground all point towards the tunnel axis. The vertical components of these displacements constitute the ground settlement. According to the equivalent ground loss theory, the maximum surface settlement is: In the formula: S max denoted as , where is the maximum surface settlement; B is the length of the first ring; μ is the Poisson's ratio of the soil; H1 is the tunnel depth; and L is the shield length.

[0035] Example 3 differs from Example 2 in that it provides an early warning method for over-excavation during tunnel boring machine (TBM) construction. In S4, based on the settlement trough theory, the volume of soil loss in the tunnel is equal to the volume of the surface settlement trough, and the settlement trough curve resembles a Gaussian distribution. The maximum surface settlement caused by over-excavation is: In the formula: B is the length of one ring; S max denoted as , where is the maximum surface settlement; i is the settlement trough width coefficient; H2 is the depth from the ground surface to the tunnel center; and Φ is the soil's internal friction angle.

[0036] Specific examples are as follows: The excavation radius R of a certain project tunnel c The tunnel depth is 7.15m, the shield shell length is 10m, the advance length of one ring B is 2.0m, the geology is silty sand, Poisson's ratio is 0.32, and the looseness coefficient K=1.2. In the 124th ring, the tunnel depth is 60m, the start time t0 is 01:24:04, the end time t1 is 03:22:32, the time t2 for the excavated material to travel from the cutterhead to the position detected by the contour sensor is 2 minutes and 5 seconds, the conveyor belt speed is 3m / s, and the measured muck discharge volume V in the 124th ring is... m 477.8m 3 The current cumulative injection volume V of the circulating water w The current cumulative injection volume V of the ring foam is 95.16 m3. f The current cumulative injection volume V of the ring bentonite is 45.10 m3. b The value is 0 m³. The surface settlement control value S at the project site is... c It is +10 / -30mm.

[0037] 1) Calculate the theoretical muck removal volume V for one ring of shield tunneling. c 2) Measured muck removal volume V of the first ring of shield tunneling m =477.8m 3 3) Calculate the over-excavation V of one ring of shield tunneling. o Calculate the total injection volume of water, foam, and bentonite in one ring of the tunnel boring machine: Calculate the volume change of the soil before and after loosening: Compare the total injection volume with the volume change of the soil before and after loosening: Calculation of actual over-excavation of soil in one ring of shield tunneling: 4) Calculate the surface settlement S caused by over-excavation. max 5) Determine whether the over-excavation amount has reached the warning value. The yellow alert range for surface subsidence of this project is: S max ≥+8.5mm or S max ≤-25.5mm, where + indicates surface uplift and - indicates surface subsidence. The red alert area for surface subsidence under this project is: S max ≥+10mm or S max ≤-30mm The surface settlement calculated based on the actual over-excavation amount is 26.9 mm, therefore the system will issue a yellow warning for over-excavation.

[0038] Example 4, based on Example 1, such as Figure 2 As shown, an early warning device for using the aforementioned shield tunneling over-excavation early warning method includes a data acquisition module, a data communication module, and a human-machine interaction module. In this embodiment, the data acquisition module is used to acquire data related to the volume of excavated soil and shield tunneling construction parameters. The excavated soil volume data includes the soil profile and conveyor belt speed. Specifically, a profile sensor collects three-dimensional point cloud data of the soil surface on the conveyor belt in real time and transmits it to the data communication module. The profile sensor is fixed above the shield conveyor belt by a bracket, with its scanning direction perpendicular to the belt's running direction, and its scanning range covering the entire belt width. An incremental encoder collects the belt's rotational speed, which is then converted to obtain the belt's running speed. The incremental encoder is connected to the belt's drive roller via a coupling. The shield tunneling construction parameters include ring advance, current ring excavation start and end times, foam injection volume, water injection volume, and bentonite injection volume.

[0039] In this embodiment, the data communication module uses either a wireless or wired communication module to transmit various information data collected by the data acquisition module to the human-machine interaction module. Wired communication: A wired communication link is established through an Ethernet switch, using the TCP / IP protocol to connect the data acquisition module and the human-machine interaction module. This is suitable for the stable construction environment inside the tunnel boring machine, ensuring high-speed and stable data transmission. Wireless communication: Equipped with a 5G industrial module and an industrial-grade 5G SIM card, it accesses the local operator's 5G network as a backup link for wired communication. When a wired link interruption is detected, it automatically switches to the wireless communication link to ensure uninterrupted data transmission.

[0040] In this embodiment, the human-machine interaction module is used to receive data transmitted by the data communication module to complete the theoretical slag discharge V. c Actual slag output V m Over-excavation volume V o Maximum surface subsidence S max The calculation is performed to execute graded early warning judgments and output early warning signals.

[0041] Furthermore, the data related to the volume of excavated soil include the excavated soil outline and the belt conveyor speed, while the shield tunneling parameters include the ring advance, the start and end time of the current ring excavation, the amount of foam injected, the amount of water injected, and the amount of bentonite injected.

[0042] Furthermore, the human-computer interaction module includes a data receiving submodule, a data processing and evaluation submodule, a visualization submodule, and a system configuration submodule; the output end of the data receiving submodule is connected to the input end of the data processing and evaluation submodule; the output end of the data processing and evaluation submodule is connected to the input end of the visualization submodule; and the system configuration submodule establishes control connections with the data receiving submodule, the data processing and evaluation submodule, and the visualization submodule, respectively.

[0043] Furthermore, the data receiving submodule transmits the received real-time monitoring data to the data processing and evaluation submodule; the data processing and evaluation submodule has a built-in calculation program for the aforementioned early warning method, which calculates the theoretical slag discharge volume V in real time. c Actual slag output V m Over-excavation volume V o and the maximum surface subsidence S max The calculation; simultaneously loading two-level early warning judgment logic, comparing with the maximum surface subsidence S max With the surface settlement control value S c The system generates early warning status information based on the relationship between the system and the data. The visualization submodule is used to display data charts such as real-time monitoring data, slag discharge statistics and early warning information, and system settings. The system configuration submodule is used to issue start and stop control commands and parameter configuration information to each submodule to realize the control of the operating status of each submodule.

[0044] Furthermore, the visualization submodule is used to display real-time monitoring data, slag discharge statistics and early warning information, system settings, and other data charts; specifically, the visualization submodule is deployed on the control panel in the tunnel boring machine control room, such as... Figure 3 As shown, various data are displayed using a graphical interface. Interface functions include: ① The top of the interface displays the equipment number, ring number, time, and real-time monitoring data. Real-time monitoring data includes belt speed, ring advance, cumulative ring injection volume, theoretical ring slag output, actual ring slag output, ring over-excavation, over-excavation evaluation, and system status. Belt speed, ring advance, and cumulative ring injection volume can be read from the PLC data table on the host computer. Theoretical ring slag output, actual ring slag output, ring over-excavation, and over-excavation evaluation are calculated and provided by the data processing and evaluation submodule. The system status is determined by the data processing and evaluation submodule based on whether the actual slag output data is communicating with the host computer; if so, it displays "Online"; otherwise, it displays "Offline".

[0045] ② The middle part of the interface displays charts showing the current ring slag discharge volume, the statistics of slag discharge volume in the last ten rings, and over-excavation warnings. The current ring slag discharge volume chart shows the measured slag discharge volume per 100mm advance, the cumulative measured slag discharge volume of the ring, and the cumulative theoretical slag discharge volume of the ring in a bar chart and a dotted line chart. The statistics module of slag discharge volume in the last ten rings shows the ring slag discharge volume and over-excavation warnings for the last 10 rings.

[0046] ③The bottom of the interface displays the equipment diagram and monitoring data.

[0047] ④ The system configuration is set at the bottom of the interface, with four buttons: "Start Measurement", "Stop Measurement", "Historical Data" and "Parameter Settings". The "Start Measurement" and "Stop Measurement" buttons are used to start and stop the control system. The "Historical Data" button is used to query the historical data of over-excavation, including time, ring number, theoretical slag output of the ring, actual slag output of the ring, over-excavation amount of the ring, and over-excavation evaluation.

[0048] Furthermore, the system configuration submodule is used for system start-up, shutdown, and parameter configuration.

[0049] In addition, the power required for the operation of the early warning device is provided by the power supply system of the tunnel boring machine.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for early warning of over-excavation in shield tunneling construction, characterized in that, Using the circumferential advance of a tunnel boring machine as the basic calculation unit, the following steps are included: S1, Calculate the theoretical muck removal volume V of one ring of shield tunneling. c Based on the design excavation volume of one ring of shield tunneling, a loosening coefficient is introduced to correct for the volume expansion effect of the soil after excavation, and the theoretical muck removal volume V is obtained. c ; S2, obtain the measured amount of slag removed (V) during the first ring of shield tunneling. m The system collects information on the surface contour of the excavated soil on the tunnel boring machine (TBM) conveyor belt and the belt's operating speed. It then extracts the start and end times of the current ring advance and calculates the measured amount of excavated soil (V) for one ring of tunneling. m ; S3, Calculate the actual over-excavation volume V of the soil during the first ring of shield tunneling. o The injection volumes of water, foam, and bentonite during shield tunneling are included in the over-excavation calculation to obtain the actual over-excavation volume V of the soil in one ring of shield tunneling. o ; S4, calculate the maximum surface settlement S caused by over-excavation. max Based on the equivalent formation loss theory or settlement trough theory, the calculated over-excavation amount V is... o Converted into the corresponding maximum surface subsidence S max ; S5, Graded Early Warning Judgment and Signal Output: Pre-set surface subsidence control value S c When the maximum surface subsidence S max Greater than the surface settlement control value S c A yellow warning signal is issued when the surface subsidence reaches 85%; when the maximum surface subsidence S... max Greater than the surface settlement control value S c At that time, a red alert signal was issued.

2. The method for early warning of over-excavation in shield tunneling construction according to claim 1, characterized in that, In S1, extract the excavation radius R of the tunnel boring machine cutterhead. c Using the advance B of the tunnel boring machine (TBM) obtained from its own sensors, the design excavation volume of one ring is calculated. The excavation volume is then multiplied by the loosening coefficient to calculate the theoretical muck removal volume of the current ring. The calculation formula is as follows: In the formula, V c R represents the theoretical slag removal volume for one ring of shield tunneling; c B is the tunnel excavation radius; B is the length of one ring advance; K is the loosening coefficient.

3. The method for early warning of over-excavation in shield tunneling construction according to claim 1, characterized in that, In S2, the contour information of the excavated soil surface on the tunnel boring machine (TBM) belt is collected by the contour sensor above the TBM belt, and the belt speed is obtained by the speed sensor at the bottom of the TBM belt. The actual measured excavated soil volume is calculated using the following formula: In the formula, V m t0 represents the measured amount of excavated material during the tunnel boring machine's first ring; A represents the cross-sectional area of ​​the excavated material profile; v represents the belt conveyor speed; t0 represents the start time of the current ring of tunnel boring machine excavation; t1 represents the end time of the current ring of tunnel boring machine excavation; and t2 represents the time it takes for the excavated material to travel from the cutterhead to the detection position of the profile sensor.

4. The method for early warning of over-excavation in shield tunneling construction according to claim 1, characterized in that, In S3, the actual over-excavation calculation process is as follows: First, calculate the total injection volume V of water, foam, and bentonite. i , Then calculate the over-excavation volume V of the first ring. o , when At that time, when At that time, In the formula, V i V represents the total injection volume of water, foam, and bentonite in one ring of the tunnel boring machine; o V represents the actual over-excavation volume of soil during the tunnel boring machine's first ring excavation. w V represents the current cumulative injection volume of the circulating water; f V represents the cumulative injection volume of the current ring foam; b This represents the current cumulative injection volume of cyclic bentonite.

5. The method for early warning of over-excavation in shield tunneling construction according to any one of claims 1 to 4, characterized in that, In S4, based on the equivalent formation loss theory, the maximum surface subsidence is: In the formula: S max denoted as , where is the maximum surface settlement; B is the length of the first ring; μ is the Poisson's ratio of the soil; H1 is the tunnel depth; and L is the shield length.

6. The method for early warning of over-excavation in shield tunneling construction according to any one of claims 1 to 4, characterized in that, In S4, according to the settlement trough theory, the maximum surface settlement caused by over-excavation is: In the formula: B is the length of one ring; S max denoted as , where is the maximum surface settlement; i is the settlement trough width coefficient; H2 is the depth from the ground surface to the tunnel center; and Φ is the soil's internal friction angle.

7. An early warning device for using the shield tunneling over-excavation early warning method according to any one of claims 1 to 6, characterized in that, It includes a data acquisition module, a data communication module, and a human-machine interaction module. The data acquisition module is used to acquire data related to the volume of excavated soil and shield tunneling parameters. The data communication module uses a wireless or wired communication module to transmit various information data collected by the data acquisition module to the human-machine interaction module. The human-machine interaction module is used to receive data transmitted by the data communication module and complete the theoretical excavation volume V. c Actual slag output V m Over-excavation volume V o Maximum surface subsidence S max The calculation is performed to execute graded early warning judgments and output early warning signals.

8. The early warning device according to claim 7, characterized in that, Data related to the volume of excavated soil includes the excavated soil outline and conveyor belt speed. Shield tunneling parameters include ring advance, current ring excavation start and end time, foam injection volume, water injection volume, and bentonite injection volume.

9. The early warning device according to claim 7, characterized in that, The human-computer interaction module includes a data receiving submodule, a data processing and evaluation submodule, a visualization submodule, and a system configuration submodule. The output of the data receiving submodule is connected to the input of the data processing and evaluation submodule. The output of the data processing and evaluation submodule is connected to the input of the visualization submodule. The system configuration submodule establishes control connections with the data receiving submodule, the data processing and evaluation submodule, and the visualization submodule, respectively.

10. The early warning device according to claim 9, characterized in that, The data receiving submodule transmits the received real-time monitoring data to the data processing and evaluation submodule; the data processing and evaluation submodule has a built-in calculation program for the aforementioned early warning method, which calculates the theoretical slag discharge volume V in real time. c Actual slag output V m Over-excavation volume V o and the maximum surface subsidence S max The calculation; simultaneously loading two-level early warning judgment logic, comparing with the maximum surface subsidence S max With the surface settlement control value S c The system generates early warning status information based on the relationship between the system and the data. The visualization submodule is used to display data charts such as real-time monitoring data, slag discharge statistics and early warning information, and system settings. The system configuration submodule is used to issue start and stop control commands and parameter configuration information to each submodule to realize the control of the operating status of each submodule.

Images