Concrete segment and internal force monitoring method

Abstract

The application discloses a concrete segment and belongs to the technical field of shield concrete segments. The application comprises a concrete segment, a pressure sensor, a stress sensor and a measuring point bottle which are installed in the concrete segment; the stress sensor is arranged on the upper and lower inner and outer curved surfaces in the interior of the concrete segment; the pressure sensor is arranged on the outer curved surface in the interior of the concrete segment; the measuring point bottle is a through-hole bottle, the measuring point bottle is arranged on the side wall in the interior of the concrete segment, and the lower port of the measuring point bottle is close to the inner side wall of the concrete segment. By arranging the pressure sensor and the stress sensor in the interior of the concrete segment, the pressure and stress changes in the interior of the segment can be monitored in real time, and important data support is provided for the safety and stability of the segment; by arranging the measuring point bottle, the reserved device of the outlet port of the formed segment can be quickly and accurately found, the reserved cable line end is taken out for data collection, and the work efficiency is effectively improved.

Description

Technical Field

[0001] This application belongs to the field of tunnel internal force monitoring technology, and more specifically relates to a concrete segment and internal force monitoring method. Background Technology

[0002] Tunnel boring machine (TBM) construction technology is one of the most advanced tunnel construction techniques in the world. TBMs can operate continuously underground, avoiding problems such as ground collapse and groundwater leakage that occur during excavation. TBM construction technology boasts advantages such as high efficiency, safety, and environmental friendliness. It can rapidly complete large-scale tunnel projects and can operate in various geological formations, demonstrating exceptional adaptability to diverse geological conditions.

[0003] The complexity of geological formations during tunnel boring machine (TBM) excavation presents extremely high risks and dangers to the construction. When conducting TBM construction on the seabed: the presence of both soft and hard strata means that the TBM must operate under varying geological conditions, demanding high stability and efficiency from the machinery; permeable sand layers further increase the complexity and risk of the construction; and the irregular shape and fragility of spheroidal weathered bodies pose significant challenges to the cutting and excavation of the TBM. Due to these complex geological conditions, TBM construction carries a high risk, and accidents could result in severe casualties and property damage.

[0004] During tunnel boring machine (TBM) excavation, it is necessary to monitor the internal forces borne by the tunnel segments under the action of the strata. By monitoring and analyzing the changes in the internal forces of the segments in real time, potential safety hazards can be identified in a timely manner, and corresponding measures can be taken for repair and reinforcement to ensure the safety and smooth progress of construction. Summary of the Invention

[0005] In order to overcome the problems existing in the prior art, this patent application provides a concrete segment and internal force monitoring method, which can monitor and analyze the changes in internal force of tunnel concrete segments in a timely manner, providing important data support for the safety and stability of construction.

[0006] In a first aspect, this application provides a concrete segment, including: a concrete segment, and a pressure sensor, a stress sensor, and a measuring point bottle installed in the concrete segment; Stress sensors are installed on the upper and lower inner and outer curved surfaces inside the concrete segment. The pressure sensor is installed on the outer arc surface inside the concrete segment; The measuring bottle is a through-hole bottle, which is installed on the inner side wall of the concrete segment, with the lower end of the measuring bottle in close contact with the inner side wall of the concrete segment. The detection cables of the pressure sensor and stress sensor pass through the upper port of the measuring point bottle and are placed inside the measuring point bottle; a sealing ring is provided at the upper port of the measuring point bottle.

[0007] By placing pressure and stress sensors inside the concrete segments, pressure and stress changes inside the segments can be monitored in real time, providing crucial data support for tunnel safety and stability. Furthermore, by setting up measuring point bottles, the pre-installed cable outlet devices can be quickly and accurately located after the concrete segments have been formed, allowing for the removal of the pre-installed cable ends for data collection, effectively improving operational efficiency.

[0008] Alternatively, in one possible implementation of the first aspect, the measuring bottle is filled with a material; the material can be cotton yarn, geotextile, or foam. By providing this material, a certain buffering and protective effect can be achieved, preventing the wires inside the measuring bottle from being affected by external vibrations and impacts, thereby improving the stability and reliability of the sensor.

[0009] Further alternatively, in one possible implementation of the first aspect, waterproof tape is affixed to the outer wall of the aforementioned measuring bottle.

[0010] By attaching waterproof tape to the outer wall of the measuring bottle, water can be effectively prevented from seeping into the bottle, improving the device's waterproof performance and protecting the sensor and cable from water damage.

[0011] Understandably, the above-mentioned technical features can be combined with each other as long as they do not conflict with each other.

[0012] Secondly, this application provides an internal force monitoring method applicable to the aforementioned concrete segments, which includes the following steps: Step 1: Measure the actual internal forces acting on the tunnel by using a monitoring ring, wherein the monitoring ring is obtained by placing the concrete segments at monitoring points within the tunnel; By analyzing the geological longitudinal profile, we can understand the properties, lithology, fault zones, and groundwater levels of the geological layers, identify potential geological risks and changes, and determine the monitoring points to be deployed within the tunnel mileage. Effective monitoring at these points allows for timely understanding of geological changes, providing crucial reference and decision-making support for construction and ensuring its safety and smooth progress. Furthermore, by installing pressure and stress sensors inside the concrete segments, we can monitor pressure and stress changes within the segments in real time. Monitoring rings are constructed from the concrete segments, and the actual measurements from the stress and pressure sensors on these rings are used for subsequent analysis, providing vital data support for the tunnel's safety and stability. Step 2: Predict the internal forces acting on the tunnel based on the analysis and prediction model to obtain the predicted values ​​of the internal forces acting on the tunnel. The analysis and prediction model is established by the data regression relationship curve composed of stress, pressure and time. Stress changes in tunnel segments are measured using stress sensors. Data on stress changes monitored at different time points are collected, and regression analysis is performed to establish a stress-time regression curve. Similarly, pressure changes in tunnel segments are measured using pressure sensors. Data on pressure changes monitored at different time points are collected, and regression analysis is performed to establish a pressure-time regression curve. By establishing these stress-time and pressure-time regression curves, the internal force changes within the tunnel can be analyzed more accurately, and the predicted internal forces acting on the tunnel over a certain period can be obtained. This provides crucial data support for construction safety and stability, and helps engineers make corresponding decisions and adjustments. Step 3: Compare the actual measured value and the predicted value to obtain a comparison result, wherein the comparison result is used to monitor the stress condition of the tunnel's internal forces; The established analytical and predictive model can predict the development of internal forces in a tunnel, and the stability of the tunnel can be judged by comparing the actual measured data with the predicted results. If the actual measured data is consistent with or close to the predicted results, it indicates that the development of internal forces in the tunnel is as expected and the tunnel structure is stable. If there is a significant difference between the actual measured data and the predicted results, there may be deformation or instability in the tunnel structure, and corresponding measures need to be taken in a timely manner.

[0013] Further optionally, in one possible implementation of the second aspect, the internal force monitoring method further includes: The internal forces acting on the tunnel are analyzed using the grey prediction analysis method to obtain the analytical values ​​of the internal forces acting on the tunnel. Step 3 specifically includes: comparing the actual measured value, the predicted value, and the analyzed value to obtain the comparison result.

[0014] Based on existing measurement data, grey predictive analysis is used to obtain the analytical values ​​of the internal forces acting on the tunnel, further predicting the development of these internal forces and thus assessing the stress state and stability of the tunnel and surrounding rock. By combining grey predictive analysis with an analytical prediction model, the changes in internal forces of concrete segments can be analyzed, providing crucial data support for construction safety and stability, and assisting engineers in making corresponding decisions and adjustments.

[0015] Further optionally, in one possible implementation of the second aspect, prior to step 1, the internal force monitoring method further includes: detecting the internal force during the fabrication process of the concrete segment.

[0016] By testing stress and pressure sensors during the concrete segment fabrication process, the accuracy of measurement data can be ensured. This is crucial for monitoring pressure and stress changes in concrete segments, providing vital data support for construction safety and stability.

[0017] Further alternatively, in one possible implementation of the second aspect, the monitoring ring is composed of six concrete segments, each of which has a stress sensor and a pressure sensor with a different number.

[0018] By numbering the stress and pressure sensors on each concrete segment, it is easier to measure the assembled segments and obtain data on pressure and stress changes, enabling more accurate regression analysis of the data and determination of the tunnel's internal force state.

[0019] The beneficial effects of this application are as follows: By installing stress and pressure sensors inside the concrete tunnel segments, this application can monitor the changes in pressure and stress within the segments in real time. Furthermore, by establishing an analytical prediction model and using grey predictive analysis, the development trend of internal forces within the segments can be predicted. By comparing actual measurement data with the prediction results, the stability of the tunnel can be assessed, and changes in geological conditions can be promptly grasped, providing important references and decision-making basis for construction. This application is simpler, faster, and provides more significant protection than conventional precast tunnel segment monitoring element installation methods, improving the survival rate of monitoring sensor element installation. It is practical and economical, and can improve the safety and stability of construction.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0021] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments of this application taken in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of this application.

[0022] Figure 1 This is a schematic diagram of the internal cross-sectional structure of the concrete segment in this application; Figure 2 This is a schematic diagram of the measuring bottle in this application; Figure 3 This is a schematic diagram of the process structure of the internal force monitoring method in this application; Figure 4 This is a schematic diagram of the cross-sectional structure of the monitoring ring in this application; Figure 5 This is a schematic diagram of the normal analysis and prediction model of the stress sensor in this application; Figure 6This is a schematic diagram of the anomalous analysis and prediction model of the stress sensor in this application.

[0023] Figure reference numerals: 1-concrete segment, 2-stress sensor, 3-pressure sensor, 4-measuring point bottle, 401-sealing ring, 402-filler. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. Furthermore, the technical features involved in the various embodiments described below can be combined with each other as long as they do not conflict with each other. The following detailed description, in conjunction with specific embodiments, further illustrates this application.

[0025] like Figure 1-2 As shown, this application provides a concrete segment, including: a concrete segment 1, and a pressure sensor 2, a stress sensor 3 and a measuring point bottle 4 disposed in the concrete segment 1. Two stress sensors 2 are installed on the upper and lower inner and outer arc surfaces inside the concrete segment 1, respectively. The stress sensors 2 are used to monitor the stress and strain inside the concrete of the segment and also to monitor the temperature, thereby determining the changes in the internal structural forces borne by the segment.

[0026] Pressure sensor 3 is installed on the outer arc surface inside the concrete segment 1; the pressure sensor 3 monitors the pressure generated on the contact surface of the concrete segment 1, and uses this to determine the pressure change of the surrounding rock on the segment.

[0027] The measuring bottle 4 is a through-hole bottle, which is installed on the inner side wall of the concrete pipe segment 1. The lower port of the measuring bottle 4 is close to the inner side wall of the concrete pipe segment 1. The detection cables of the stress sensor 2 and the pressure sensor 3 pass through the upper port of the measuring bottle 4 and are placed in the measuring bottle 4. A sealing ring 401 is provided at the upper port of the measuring bottle 4.

[0028] This application's solution, by placing stress sensor 2 and pressure sensor 3 inside the concrete segment 1, can monitor the pressure and stress changes inside the concrete segment 1 in real time, providing important data support for the safety and stability of the tunnel; by setting measuring point bottle 4, the pre-reserved device at the outlet port of the formed concrete segment 1 can be quickly and accurately located, and the pre-reserved cable end can be taken out for data collection, effectively improving the efficiency of monitoring operations.

[0029] Specifically, optionally, a filler 402 can be provided inside the measuring bottle 4; the filler 402 can be cotton yarn, geotextile, foam, etc. By providing the filler 402, a certain buffering and protection function can be provided to prevent the wires inside the measuring bottle 4 from being affected by external vibration and impact, thereby improving the stability and reliability of the sensor.

[0030] Optionally, waterproof tape can be affixed to the outer wall of the measuring bottle 4. By affixing waterproof tape to the outer wall of the measuring bottle 4, moisture can be effectively prevented from seeping into the measuring bottle, improving the waterproof performance of the device and protecting the sensor and cable from water.

[0031] like Figure 3-5 As shown, an internal force monitoring method is applicable to the aforementioned concrete tunnel segments with internal force monitoring function. This internal force monitoring method includes the following steps: Step 1: Measure the actual internal forces acting on the tunnel by using a monitoring ring, wherein the monitoring ring is obtained by placing the concrete segments at monitoring points within the tunnel; During underwater shield tunneling, the geological strata are complex, including both soft and hard layers. Some sections pass through permeable sand layers and spheroidal weathered bodies. Therefore, it is necessary to analyze the geological conditions of the longitudinal geological profile to determine the monitoring points to be placed along the tunnel mileage. Effective monitoring at these points allows for timely understanding of changes in geological conditions, providing crucial references and decision-making basis for construction, ensuring its safety and smooth progress. By placing pressure and stress sensors inside the concrete segments, real-time monitoring of pressure and stress changes within the segments is possible. Furthermore, by monitoring the concrete segments to form a monitoring ring, the actual measured values ​​of each stress and pressure sensor on the monitoring ring are used for subsequent analysis, providing vital data support for the tunnel's safety and stability.

[0032] Step 2: Predict the internal forces acting on the tunnel based on the analysis and prediction model to obtain the predicted values ​​of the internal forces acting on the tunnel. The analysis and prediction model is established by the data regression relationship curve composed of stress, pressure and time. Analyze the internal forces acting on the tunnel based on the grey prediction analysis method to obtain the analyzed values ​​of the internal forces acting on the tunnel. Stress changes in tunnel segments are measured using stress sensors. Data on stress changes monitored at different time points are collected, and regression analysis is performed to establish a stress-time regression curve. Similarly, pressure changes in tunnel segments are measured using pressure sensors. Data on pressure changes monitored at different time points are collected, and regression analysis is performed to establish a pressure-time regression curve. By establishing these stress-time and pressure-time regression curves, the internal force changes within the tunnel can be analyzed more accurately, and the predicted internal forces acting on the tunnel over a certain period can be obtained. This provides crucial data support for construction safety and stability, and helps engineers make corresponding decisions and adjustments.

[0033] like Figure 5 As shown, the analysis and prediction model established based on the measurement data of the stress sensor is illustrated. The origin coordinates of the figure represent the initial state of the stress sensor after installation. The horizontal axis represents the change of the stress sensor over time after installation, and the vertical axis represents the displacement change of the stress sensor measured at different time points (displacement change represents the stress change). Based on the analysis and prediction model, the displacement change law of the stress sensor can be understood, and the displacement value at a certain moment and the final displacement value can be calculated. When the displacement-time relationship curve tends to flatten, the tunnel tends to be stable. The specific process of judgment based on the analysis and prediction model is as follows: The analysis and prediction model is used to predict the changes in internal forces on the tunnel over a period of time, and a predicted displacement-time relationship curve is generated. Then, over the next period, measurements are taken on the monitoring ring at regular intervals, and the actual displacement-time relationship curve is plotted based on the measurement data. The predicted displacement-time relationship curve is compared with the actual displacement-time relationship curve to observe the fitting relationship. If the fitting relationship is good, it indicates that the actual situation matches the prediction, and the tunnel is relatively stable; if the fitting relationship is poor, such as... Figure 6 As shown, when the displacement-time curve suddenly becomes steep, it indicates that an abnormal situation has occurred in the tunnel. It is necessary to compare the error between the actual value and the predicted value in a timely manner and take corresponding measures according to the error to ensure the safety and stability of the tunnel.

[0034] Based on existing measurement data, the grey predictive analysis method is used to obtain the analytical values ​​of the internal forces acting on the tunnel. This allows for further prediction of the development of these internal forces, and consequently, a judgment is made regarding the stress state and stability of the tunnel and surrounding rock. Specifically, the judgment process involves: predicting the analytical values ​​of the internal forces acting on the tunnel at a certain time point using grey predictive analysis; measuring the internal forces on the tunnel at that time point to obtain the actual values; and then judging the stability of the tunnel by comparing the difference between the analytical values ​​and the actual values.

[0035] Step 3: Compare the actual measured value, the predicted value, and the analyzed value to obtain the comparison result; By combining grey prediction analysis with an analytical prediction model, the internal force changes of concrete segments can be analyzed, providing important data support for construction safety and stability, and helping engineers make corresponding decisions and adjustments.

[0036] Specifically, optionally, before step 1, the internal force monitoring method further includes: detecting the internal force during the fabrication process of the concrete segment.

[0037] The specific monitoring process is as follows: Stress and pressure sensors are embedded in the reinforcing steel bars within the concrete segment. The pressure sensors are embedded on the outside of the segment, while one stress sensor is embedded on each side. Before embedding, the stress and pressure sensors are tested. After embedding and placing the steel membrane, the stress and pressure sensors are tested again. After demolding the concrete segment, the testing cable is removed from the measuring bottle, and the stress and pressure sensors are tested. After measurement, the cable is put back into the measuring bottle, and the bottle is sealed with fireproof sealant. The demolded concrete segment is placed in a curing tank for curing. After removing it from the curing tank, the stress and pressure sensors are tested again. After the concrete segment is transported to the on-site work platform, the stress and pressure sensors are tested before installation, and again after assembly. If abnormal measurement results are found during testing, the stress and pressure sensors need to be inspected to ensure proper operation and adherence to correct testing methods.

[0038] By testing stress and pressure sensors at each stage of the manufacturing process, the accuracy of the measurement data can be guaranteed. This is crucial for monitoring pressure and stress changes in concrete tunnel segments, providing vital data support for safe and stable construction.

[0039] Specifically, the aforementioned monitoring ring can be configured to consist of six concrete segments, each with its own stress sensor and pressure sensor numbered differently. Figure 4 As shown.

[0040] Two stress measuring points were set up on each concrete segment, for a total of 12 measuring points, numbered R1 to R12; one pressure measuring point was set up on each concrete segment, for a total of 6 measuring points, numbered E1 to E6. During measurement, the detection cables on the stress and pressure sensors were extended, and different colors were used to distinguish the cables corresponding to different functions. For example, the stress sensor cable was a four-core cable, with the strain gauge and thermometer distinguished by the color of the core wires: red and black wires for frequency testing, and green and white wires for thermometer testing. Depending on the actual site conditions, each cable was extended to a temporary observation station for measuring the assembled segments; or, the assembled segments were measured using the assembly platform.

[0041] By numbering the stress and pressure sensors on each concrete segment, extending the detection cables, and differentiating them by color, it becomes easier to measure the assembled segments and obtain data on pressure and stress changes. This data is crucial for monitoring the stress state of the segments and ensuring construction safety, enabling more accurate regression analysis and assessment of the tunnel's stress state.

[0042] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the application and are not intended to limit it. Although the application has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the protection scope of the application.

Claims

1. A method for monitoring internal forces, characterized in that, The internal force monitoring method is applicable to concrete segments, wherein the concrete segments include pressure sensors, stress sensors and measuring point bottles installed therein; The stress sensor is installed on the upper and lower inner and outer arc surfaces inside the concrete segment; the pressure sensor is installed on the outer arc surface inside the concrete segment; the measuring bottle is a through-hole bottle, installed on the inner side wall of the concrete segment, with the lower port of the measuring bottle in close contact with the inner side wall of the concrete segment; the detection cables of the pressure sensor and the stress sensor pass through the upper port of the measuring bottle and are placed inside the measuring bottle; a sealing ring is provided at the upper port of the measuring bottle; The measuring bottle is filled with a filling material; the filling material is at least one of the following: cotton yarn, geotextile, or foam. Waterproof tape is attached to the outer wall of the measuring point bottle; The internal force monitoring method includes: Step 1: Measure the actual internal forces acting on the tunnel by using a monitoring ring, wherein the monitoring ring is obtained by placing the concrete segments at monitoring points within the tunnel; Step 2: Predict the internal forces acting on the tunnel based on the analysis and prediction model to obtain the predicted values ​​of the internal forces acting on the tunnel. The analysis and prediction model is established by the data regression relationship curve composed of stress, pressure and time. Step 3: Compare the actual measured value and the predicted value to obtain a comparison result, wherein the comparison result is used to monitor the stress condition of the tunnel's internal forces; The internal force monitoring method also includes: The internal forces acting on the tunnel are analyzed using the grey prediction analysis method to obtain the analytical values ​​of the internal forces acting on the tunnel. Step 3 specifically includes: comparing the actual measured value, the predicted value, and the analyzed value to obtain the comparison result.

2. The internal force monitoring method according to claim 1, characterized in that, Prior to step 1, the internal force monitoring method further includes: During the fabrication process of the concrete segments, they are inspected.

3. The internal force monitoring method according to claim 2, characterized in that, The monitoring ring consists of 6 concrete segments, and the stress sensor and pressure sensor on each concrete segment are assigned different numbers.

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