A Ground Settlement Monitoring Method and System Based on Weak Grating Array Monitoring

Abstract

The present invention relates to the technical field of building construction, and particularly to a ground settlement monitoring method and system based on weak grating array monitoring. The method includes: obtaining real-time strain and settlement; determining a first temporary area; determining a second temporary area; obtaining the width of bulges and cracks; adjusting a preset synchronization threshold; correcting a settlement amount threshold; and sending an abnormal prompt. Through the high-precision monitoring ability of the weak grating array, the present invention realizes the real-time dynamic tracking of ground settlement during subway construction, improves the recognition accuracy of abnormal settlement, adopts a step-by-step screening and dynamic threshold adjustment method, can effectively reduce misjudgment, and combined with the analysis of the change in the width of bulges and cracks, can more accurately judge the settlement trend and potential risks, reduce false alarms caused by formation disturbance or construction vibration, ensure the stability of subway construction and the surrounding environment, and effectively solve the problem of low accuracy of monitoring results caused by relying on static and single monitoring data.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and particularly to a ground settlement monitoring method and system based on weak grating array monitoring. Background Art

[0002] With the rapid development of urban subway construction, shield construction has become a common construction method in underground engineering. However, during shield construction, due to reasons such as changes in soil layer pressure and construction technical factors, problems such as ground settlement and deformation may occur, and even potential safety hazards to surrounding buildings or infrastructure may be caused. The phenomena caused by these reasons are often difficult to detect and accurately evaluate in a timely manner through traditional monitoring methods, affecting the safety and stability of construction. Especially in urban dense areas, the impact of shield construction on the environment is more prominent. How to efficiently and real-time monitor and warn of ground settlement and bulging phenomena has become an urgent technical problem to be solved.

[0003] The patent document with the publication number of CN103363954A discloses a ground settlement monitoring system, which includes: a groundwater level monitoring unit for respectively collecting and monitoring the real-time data of the groundwater levels at each monitoring point set in the monitored area, and a subsurface formation monitoring unit for respectively collecting and monitoring the compression amount and expansion amount of each soil layer underground at each monitoring point. The groundwater level monitoring unit and the subsurface formation monitoring unit at each monitoring point output the collected data to a data acquisition unit for storage and sorting, and the data acquisition unit then outputs the data to a data processing unit to analyze and real-time monitor the ground settlement in this area.

[0004] It can be seen that the ground settlement monitoring system has the following problems: Storing and sorting the data first in the system and then transmitting it to the data processing unit for analysis will cause a lag in data processing, and it is impossible to achieve real-time dynamic monitoring and rapid response; the system overly relies on changes in groundwater level and soil layer to judge the settlement situation, resulting in a decrease in the accuracy of monitoring results. Summary of the Invention

[0005] For this reason, the present invention provides a ground settlement monitoring method and system based on weak grating array monitoring, so as to overcome the problem of low accuracy of monitoring results caused by relying on static and single monitoring data in the prior art through real-time monitoring and dynamically adjusting the monitoring accuracy.

[0006] To achieve the above object, on the one hand, the present invention provides a ground settlement monitoring method based on weak grating array monitoring, including:

[0007] Obtaining the real-time strain value and real-time ground settlement amount of each weak grating array acquisition area during subway shield construction;

[0008] Determine a number of first temporary areas according to the real-time ground settlement amount and the preset settlement amount threshold;

[0009] Determine a number of second temporary areas according to the real-time ground settlement amount, the real-time strain value and the preset synchronization threshold of each of the first temporary areas;

[0010] Obtain the real-time crack width at each bulge in the second temporary area according to the real-time strain value in all the second temporary areas;

[0011] Adjust the preset synchronization threshold according to the real-time crack width within the preset adjustment duration to form an adjusted synchronization threshold;

[0012] Correct the preset settlement amount threshold according to the number of the second temporary areas determined based on the adjusted synchronization threshold within the preset correction duration to form a corrected settlement amount threshold;

[0013] Determine a number of abnormal settlement areas according to the real-time crack width obtained based on the corrected settlement amount threshold within the preset determination duration;

[0014] Send out an abnormal prompt according to the abnormal settlement area.

[0015] Further, determining a number of first temporary areas according to the real-time ground settlement amount and the preset settlement amount threshold includes:

[0016] When the real-time ground settlement amount is greater than the preset settlement amount threshold, determine that the weak grating array acquisition area is the first temporary area to determine a number of first temporary areas.

[0017] Further, determining a number of second temporary areas according to the real-time ground settlement amount, the real-time strain value and the preset synchronization threshold of each of the first temporary areas includes:

[0018] Calculate the standard deviation of all the real-time ground settlement amounts within the preset synchronous calculation duration to form a settlement amount fluctuation value;

[0019] Calculate the standard deviation of all the real-time strain values within the preset synchronous calculation duration to form a strain fluctuation value;

[0020] Determine a number of second temporary areas according to the settlement amount fluctuation value, the strain fluctuation value and the preset synchronization threshold.

[0021] Further, determining a number of second temporary areas according to the settlement amount fluctuation value, the strain fluctuation value and the preset synchronization threshold includes:

[0022] Draw a change curve of the settlement amount fluctuation value within the preset synchronous calculation duration to form a settlement fluctuation curve;

[0023] Plot the change curve of the strain fluctuation value within the preset synchronous calculation duration to form a strain fluctuation curve;

[0024] Calculate the cosine similarity between the settlement fluctuation curve and the strain fluctuation curve to form a synchronization degree;

[0025] When the synchronization degree is less than the preset synchronization degree threshold, determine the first temporary area as the second temporary area to determine a number of second temporary areas.

[0026] Further, obtaining the real-time crack width at each bulge in the second temporary area according to the real-time strain values in all the second temporary areas includes:

[0027] Calculate the standard deviation of all the real-time strain values to form a strain distribution value;

[0028] When the strain distribution value is greater than the preset strain distribution threshold, obtain the real-time crack width at each bulge in the second temporary area according to the real-time strain values of any two adjacent second temporary areas.

[0029] Further, obtaining the real-time crack width at each bulge in the second temporary area according to the real-time strain values of any two adjacent second temporary areas includes:

[0030] Obtain the distance between the two second temporary areas;

[0031] Calculate the difference between the real-time strain values of the two second temporary areas to form a strain difference;

[0032] Calculate the ratio of the strain difference to the distance to form a strain gradient;

[0033] When the strain gradient is greater than the preset gradient threshold, determine the midpoint of the two second temporary areas as the midpoint of the bulge to form a bulge midpoint;

[0034] Obtain the widths of all cracks within a circular area with the bulge midpoint as the center and a preset bulge length as the radius;

[0035] Calculate the average value of all the widths to form a real-time crack width.

[0036] Further, adjusting the preset synchronization degree threshold according to the real-time crack width within the preset adjustment duration to form an adjusted synchronization degree threshold includes:

[0037] Calculate the standard deviation of the real-time crack width to form a first width fluctuation value;

[0038] When the first width fluctuation value is greater than a preset first width fluctuation threshold, the preset synchronization threshold is reduced according to the relative deviation between the crack width fluctuation value and the preset width fluctuation threshold and a preset adjustment coefficient to form an adjusted synchronization threshold.

[0039] Further, correcting the preset settlement threshold according to the number of the second temporary regions determined based on the adjusted synchronization threshold within a preset correction duration to form a corrected settlement threshold includes:

[0040] Calculating the standard deviation of the number of the second temporary regions to form a quantity fluctuation value;

[0041] When the quantity fluctuation value is greater than a preset quantity fluctuation threshold, calculating the relative deviation between the quantity fluctuation value and the preset quantity fluctuation threshold to form a quantity fluctuation deviation;

[0042] When the quantity fluctuation deviation is greater than a preset fluctuation deviation threshold, reducing the preset settlement threshold according to the relative deviation between the quantity fluctuation deviation and the preset fluctuation deviation threshold and a preset correction coefficient to form a corrected settlement threshold.

[0043] Further, determining a plurality of abnormal settlement regions according to the real-time crack width obtained based on the corrected settlement threshold within a preset determination duration includes:

[0044] Calculating the standard deviation of the real-time crack width to form a second width fluctuation value;

[0045] When the second width fluctuation value is greater than a preset second width fluctuation threshold, determining the corresponding circular region as the abnormal settlement region to determine a plurality of abnormal settlement regions.

[0046] On the other hand, the present invention further provides a ground settlement monitoring system based on weak grating array monitoring, including:

[0047] A first acquisition module for acquiring the real-time strain value and the real-time ground settlement amount of each weak grating array acquisition region during subway shield construction;

[0048] A first determination module connected to the first acquisition module for determining a plurality of first temporary regions according to the real-time ground settlement amount and a preset settlement threshold;

[0049] A second determination module respectively connected to the first acquisition module and the first determination module for determining a plurality of second temporary regions according to the real-time ground settlement amount, the real-time strain value of each of the first temporary regions, and a preset synchronization threshold;

[0050] A second acquisition module, which is connected to the second determination module, is configured to obtain the real-time crack width at each bulge in the second temporary area according to the real-time strain values in all the second temporary areas;

[0051] An adjustment module, which is respectively connected to the second determination module and the second acquisition module, is configured to adjust the preset synchronization threshold according to the real-time crack width within a preset adjustment duration to form an adjusted synchronization threshold;

[0052] A correction module, which is respectively connected to the first determination module, the adjustment module and the second determination module, is configured to correct the preset settlement amount threshold according to the number of the second temporary areas determined based on the adjusted synchronization threshold within a preset correction duration to form a corrected settlement amount threshold;

[0053] A third determination module, which is respectively connected to the correction module and the second acquisition module, is configured to determine a plurality of abnormal settlement areas according to the real-time crack width obtained based on the corrected settlement amount threshold within a preset determination duration;

[0054] A prompt module, which is connected to the third determination module, is configured to issue an abnormal prompt according to the abnormal settlement area.

[0055] Compared with the prior art, the beneficial effects of the present invention are as follows: through the high-precision monitoring ability of the weak grating array, the real-time and dynamic tracking of the ground settlement during the subway construction process is realized, the recognition accuracy of the abnormal settlement is improved, and the misjudgment can be effectively reduced and the adaptability of the monitoring system can be improved by adopting the method of step-by-step screening and dynamic threshold adjustment. At the same time, by combining the analysis of the change in the crack width of the bulge, the settlement trend and potential risks can be judged more accurately, and the false alarm caused by the formation disturbance or construction vibration can be reduced, so as to optimize the construction safety management, reduce the settlement risk, ensure the stability of the subway construction and the surrounding environment, and effectively solve the problem of low accuracy of the monitoring results due to relying on static and single monitoring data.

[0056] Furthermore, by means of hierarchical screening and dynamic threshold adjustment, the misjudgment rate is effectively reduced, and the abnormal detection is made more reliable. The weak grating array monitoring technology is adopted to ensure the accuracy of data acquisition, and through the monitoring of the crack width at the bulge, the fine-grained analysis of the formation disturbance can be realized, and the hidden dangers caused by the construction vibration can be found in time. In addition, the automated monitoring process reduces the cost of manual inspection, improves the real-time performance of early warning, and helps to ensure the long-term stability of the subway structure and the surrounding buildings.

[0057] Furthermore, by calculating the standard deviation to analyze the fluctuations of the settlement amount and strain value, the fine recognition ability of formation disturbance is improved, the screening of abnormal settlement areas is made more accurate, the interference of environmental noise and local abnormal data can be effectively reduced, and the stability and reliability of monitoring data are improved. At the same time, by setting the preset synchronization threshold, it is ensured that the second temporary area selected can truly reflect the dynamic relationship between settlement and strain, thereby improving the accuracy of subsequent crack monitoring and abnormal warning.

[0058] Furthermore, by plotting the settlement and strain fluctuation curves and calculating their synchronization degree, the unstable areas of formation deformation can be effectively identified, avoiding misjudgment that may be caused by a single threshold judgment. At the same time, by using cosine similarity for analysis, the recognition accuracy is improved, and the areas with poor synchronization can be more accurately screened out, thereby optimizing the determination of abnormal settlement areas and improving the sensitivity and reliability of monitoring.

[0059] Furthermore, by calculating the strain distribution value through the standard deviation, the areas where strain anomalies are concentrated can be accurately identified, and the crack width can be determined by combining the change trend of the strain value in the adjacent areas, improving the accuracy of crack recognition. It can not only effectively detect the bulging deformation of the formation, but also provide finer-grained crack information for settlement monitoring, making the monitoring results more accurate and improving the safety and warning ability during subway construction.

[0060] Furthermore, by calculating the strain gradient, the formation position of the bulge can be accurately located to ensure the accuracy of bulge detection. At the same time, analyzing the crack width with the bulge as the center makes the crack monitoring range more targeted and improves the reliability of crack width calculation. Combining the deformation characteristics of the local area, potential hazards that may affect subway construction safety can be timely identified, providing more accurate data support for subsequent adjustment and correction.

[0061] Furthermore, by dynamically adjusting the preset synchronization threshold, it is possible to flexibly respond to the large fluctuations in crack width during the construction process, improve the sensitivity and accuracy of monitoring, ensure that the minute changes in ground settlement and deformation can be timely captured, and enhance the real-time response ability and monitoring accuracy of monitoring.

[0062] Furthermore, by dynamically adjusting the settlement amount threshold according to the actual fluctuation situation of the number of the second temporary areas monitored, the accuracy of settlement monitoring is improved. When the abnormal settlement fluctuation within the area increases, the threshold can be timely adjusted to prevent false alarms caused by overly strict thresholds, and at the same time ensure an accurate response to real settlement abnormal events, effectively improving the sensitivity and reliability of monitoring.

[0063] Furthermore, through the analysis of the crack width fluctuations, the abnormal settlement areas caused by settlement can be accurately identified, thus quickly responding to potential construction risks. By setting a reasonable fluctuation threshold, over-sensitive detections can be avoided, ensuring the stability and efficiency of the monitoring system. At the same time, early warnings can be issued in a timely manner, providing an effective basis for subsequent construction adjustments.

[0064] Furthermore, through the precise real-time monitoring of ground settlement, the monitoring parameters can be dynamically adjusted according to the actual data during the construction process, providing more refined abnormal detections. By adjusting the preset synchronization threshold and the preset settlement amount threshold, the system improves the accuracy and flexibility of the monitoring, avoiding potential construction safety hazards caused by the failure to detect settlement problems in a timely manner. In addition, the early identification of abnormal settlement areas can help relevant personnel quickly take measures, effectively reducing construction risks and improving construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 is a flowchart of the ground settlement monitoring method based on the weak grating array in this embodiment;

[0066] Figure 2 is a decision logic diagram for determining the first temporary area in this embodiment;

[0067] Figure 3 is a decision logic diagram for determining the second temporary area in this embodiment;

[0068] Figure 4 is a schematic diagram of the ground settlement monitoring system based on the weak grating array in this embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0069] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0070] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0071] Please refer to Figure 1 shown, which is a flowchart of the ground settlement monitoring method based on the weak grating array in this embodiment;

[0072] On the one hand, this embodiment provides a ground settlement monitoring method based on the weak grating array, including:

[0073] Obtaining the real-time strain values and real-time ground settlement amounts of each weak grating array acquisition area during the subway shield construction process;

[0074] Determine a number of first temporary areas according to the real-time ground settlement amount and the preset settlement amount threshold;

[0075] Determine a number of second temporary areas according to the real-time ground settlement amount, the real-time strain value and the preset synchronization threshold of each of the first temporary areas;

[0076] Obtain the real-time crack width at each bulge in the second temporary area according to the real-time strain value in all the second temporary areas;

[0077] Adjust the preset synchronization threshold according to the real-time crack width within the preset adjustment duration to form an adjusted synchronization threshold;

[0078] Modify the preset settlement amount threshold according to the number of the second temporary areas determined based on the adjusted synchronization threshold within the preset correction duration to form a corrected settlement amount threshold;

[0079] Determine a number of abnormal settlement areas according to the real-time crack width obtained based on the corrected settlement amount threshold within the preset determination duration;

[0080] Send an abnormal prompt according to the abnormal settlement area.

[0081] The weak grating array acquisition area refers to a specific surface area monitored by weak grating array sensors arranged in the subway construction area. These sensors use fiber optic grating technology and can monitor the strain value and ground settlement amount of this area in real time. When the sensors are affected by ground settlement or deformation, the optical signal will change, thus reflecting the strain and settlement conditions. The sensors are evenly distributed in the construction area in the form of a square grid to ensure that there are enough monitoring points in each acquisition area. This distribution method helps to provide more accurate and comprehensive ground settlement monitoring data, forming a dense monitoring network for real-time tracking and analysis of ground deformation conditions.

[0082] The real-time strain value refers to the degree of deformation of the ground or structure under the action of external forces (such as construction vibration, soil settlement, etc.) monitored in real time by the weak grating array sensors. The strain value reflects the deformation of the object and is usually expressed by the deformation amount per unit length. Through the fiber optic grating sensors, the strain conditions at different positions of the ground or structure can be accurately captured, and converted into real-time optical signal changes, and then the specific strain value can be obtained.

[0083] The real-time ground settlement amount refers to the vertical displacement of the ground caused by construction or other external forces, which is monitored in real time by sensors. It represents the degree of ground subsidence in a specific area and is an important parameter for measuring ground settlement or structural deformation. By monitoring the changes in the surrounding optical signals, the sensor can obtain the displacement amount of the ground in the vertical direction in real time, thus providing real-time data on ground settlement.

[0084] During the shield tunneling construction process, the bulge phenomenon is caused by the formation disturbance induced by vibration, and its formation mechanism may involve overexcavation, uneven synchronous grouting, formation loosening or stress redistribution. The generation of cracks is the result of the further development of the bulge.

[0085] The preset settlement amount threshold refers to the reference value for judging whether the ground settlement is abnormal, which depends on the geological conditions, construction technology and safety standards of the construction area. It is usually between 5 mm and 30 mm. In this embodiment, it is set to 10 mm to detect potential settlement risks in a timely manner.

[0086] The preset synchronization threshold is used to measure the correlation degree between the ground settlement amount and the strain value in each acquisition area, which depends on the sensitivity and error range of the monitoring system. It is usually between 0.7 and 0.95. In this embodiment, it is set to 0.85 to ensure the accuracy and reliability of the monitoring data.

[0087] The preset adjustment duration refers to the duration for observing the change in the real-time crack width before adjusting the preset synchronization threshold, which depends on the construction speed and geological stability. It is usually between 1 hour and 24 hours. In this embodiment, it is set to 6 hours to quickly respond to the change in the settlement trend.

[0088] The preset correction duration refers to the time for observing the change in the number of the second temporary areas before correcting the settlement amount threshold, which depends on the evolution speed of the ground settlement. It is usually between 12 hours and 72 hours. In this embodiment, it is set to 24 hours to ensure the stability and adaptability of the threshold adjustment.

[0089] The preset determination duration refers to the monitoring time before finally determining the abnormal settlement area, which depends on the engineering safety requirements and the time scale of the settlement development. It is usually between 24 hours and 168 hours. In this embodiment, it is set to 48 hours to ensure the accuracy of the abnormal determination and avoid misjudgment or delayed response.

[0090] Based on the weak grating array sensing technology, by real-time monitoring the strain values and ground settlement amounts in each acquisition area during subway construction, potential settlement abnormal areas are gradually screened out. First, according to the real-time ground settlement amount and the preset threshold, the first temporary area where settlement risks may exist is initially determined; subsequently, combined with the preset synchronization threshold, the second temporary area greatly affected by construction is further screened out, and the crack width at the bulge position therein is monitored. Then, the preset synchronization threshold is dynamically adjusted within the preset adjustment duration to optimize the judgment criteria, and the settlement amount threshold is corrected within the preset correction duration to adapt to the changes in the construction environment. Finally, within the preset determination duration, the crack width is continuously monitored according to the corrected threshold, the abnormal settlement area is determined, and an abnormal prompt is issued to achieve accurate early warning.

[0091] Through the high-precision monitoring ability of the weak grating array, the real-time and dynamic tracking of ground settlement during subway construction is realized, the recognition accuracy of abnormal settlement is improved. By adopting the method of gradual screening and dynamic adjustment of thresholds, false judgments can be effectively reduced, and the adaptability of the monitoring system can be improved. At the same time, combined with the analysis of the change in the crack width of the bulge, the settlement trend and potential risks can be judged more accurately, and false alarms caused by formation disturbance or construction vibration can be reduced, thereby optimizing the construction safety management, reducing the settlement risk, ensuring the stability of subway construction and the surrounding environment, and effectively solving the problem of low accuracy of monitoring results caused by relying on static and single monitoring data.

[0092] Please continue to refer to Figure 2 as shown, which is the decision logic diagram for determining the first temporary area in this embodiment;

[0093] Determining several first temporary areas according to the real-time ground settlement amount and the preset settlement amount threshold includes:

[0094] When the real-time ground settlement amount is greater than the preset settlement amount threshold, it is determined that the acquisition area of the weak grating array is the first temporary area to determine several first temporary areas.

[0095] By obtaining the real-time strain value and real-time ground settlement amount of the weak grating array acquisition area, first judge whether the real-time ground settlement amount exceeds the preset settlement amount threshold to screen out the first temporary area. Subsequently, within the first temporary area, combined with the real-time strain value and the synchronization threshold, the second temporary area is further screened out, and the real-time crack width at the bulge is detected therein. The synchronization threshold is dynamically adjusted through the preset adjustment duration, and the settlement amount threshold is corrected according to the number of the second temporary areas within the preset correction duration to adapt to different settlement characteristics. Finally, within the preset determination duration, based on the corrected settlement amount threshold and the crack width, the abnormal settlement area is accurately identified, and an abnormal prompt is issued to realize the whole-process settlement monitoring and early warning.

[0096] By means of hierarchical screening and dynamic threshold adjustment, the false positive rate is effectively reduced, making the anomaly detection more reliable. The weak grating array monitoring technology is adopted to ensure the accuracy of data acquisition. Through the monitoring of the crack width at the bulge, a fine-grained analysis of the formation disturbance is realized, and potential hazards caused by construction vibration can be detected in a timely manner. In addition, the automated monitoring process reduces the cost of manual inspection, improves the real-time performance of early warning, and helps to ensure the long-term stability of the subway structure and surrounding buildings.

[0097] Specifically, determining a plurality of second temporary regions according to the real-time ground settlement amount, the real-time strain value and a preset synchronization threshold of each of the first temporary regions includes:

[0098] Calculating the standard deviation of all the real-time ground settlement amounts within a preset synchronous calculation duration to form a settlement amount fluctuation value;

[0099] Calculating the standard deviation of all the real-time strain values within the preset synchronous calculation duration to form a strain fluctuation value;

[0100] Determining a plurality of second temporary regions according to the settlement amount fluctuation value, the strain fluctuation value and the preset synchronization threshold.

[0101] The preset synchronous calculation duration refers to the time window selected when calculating the settlement amount fluctuation value and the strain fluctuation value, which is used to ensure the temporal consistency of data and depends on the change rates of settlement and strain during the subway construction process, as well as the data acquisition frequency of the monitoring system. It is usually set between 5 minutes and 30 minutes. In this embodiment, it is set to 10 minutes, which can effectively capture the short-term dynamic changes of the formation disturbance and reduce the influence of instantaneous noise.

[0102] First, within the first temporary region, by calculating the standard deviation of all the real-time ground settlement amounts within the preset synchronous calculation duration, the settlement amount fluctuation value is obtained, and at the same time, the standard deviation of all the real-time strain values within the corresponding duration is calculated to obtain the strain fluctuation value. Subsequently, these two fluctuation values are compared with the preset synchronization threshold to screen out the regions with significant synchronous changes, and finally a plurality of second temporary regions are determined. This process can effectively identify the correlation between the settlement amount and the strain value, and further lock the key regions where abnormal settlement may occur.

[0103] By calculating the standard deviation to analyze the fluctuation conditions of the settlement amount and the strain value, the fine recognition ability of the formation disturbance is improved, the screening of abnormal settlement regions is made more accurate, the interference of environmental noise and local abnormal data can be effectively reduced, and the stability and reliability of the monitoring data are improved. At the same time, through the setting of the preset synchronization threshold, it is ensured that the selected second temporary regions can truly reflect the dynamic relationship between settlement and strain, thereby improving the accuracy of subsequent crack monitoring and abnormal early warning.

[0104] Please continue to refer toFigure 3 As shown, it is the determination logic diagram for determining the second temporary area in this embodiment;

[0105] Determining a number of second temporary areas according to the settlement fluctuation value, the strain fluctuation value, and the preset synchronization threshold includes:

[0106] Plot the change curve of the settlement fluctuation value within the preset synchronization calculation duration to form a settlement fluctuation curve;

[0107] Plot the change curve of the strain fluctuation value within the preset synchronization calculation duration to form a strain fluctuation curve;

[0108] Calculate the cosine similarity of the settlement fluctuation curve and the strain fluctuation curve to form a synchronization degree;

[0109] When the synchronization degree is less than the preset synchronization threshold, determine the first temporary area as the second temporary area to determine a number of second temporary areas.

[0110] Within the preset synchronization calculation duration, calculate the settlement fluctuation value and the strain fluctuation value, and plot the corresponding fluctuation curves. Then, use the cosine similarity to calculate the synchronization degree of the settlement fluctuation curve and the strain fluctuation curve. If the synchronization degree of a certain first temporary area is lower than the preset synchronization threshold, then determine this area as the second temporary area, so as to screen out a number of second temporary areas and provide a basis for subsequent analysis.

[0111] By plotting the settlement and strain fluctuation curves and calculating their synchronization degrees, the unstable areas of formation deformation can be effectively identified, avoiding misjudgments that may be caused by a single threshold judgment. At the same time, using the cosine similarity for analysis improves the recognition accuracy, can more accurately screen out the areas with poor synchronization, thereby optimizing the determination of abnormal settlement areas and enhancing the sensitivity and reliability of monitoring.

[0112] Specifically, obtaining the real-time crack width at each bulge in the second temporary area according to the real-time strain values in all the second temporary areas includes:

[0113] Calculate the standard deviation of all the real-time strain values to form a strain distribution value;

[0114] When the strain distribution value is greater than the preset strain distribution threshold, obtain the real-time crack width at each bulge in the second temporary area according to the real-time strain values of any two adjacent second temporary areas.

[0115] Within all the second temporary regions, calculate the standard deviation of the real-time strain values in each region to obtain the strain distribution value. When this distribution value exceeds the preset strain distribution threshold, it indicates that significant deformation may exist in this region. Subsequently, by analyzing the changes in the real-time strain values of adjacent second temporary regions, calculate and obtain the real-time crack width at the bulge, providing a basis for subsequent adjustment and correction.

[0116] Calculating the strain distribution value through the standard deviation can accurately identify the regions where strain is abnormally concentrated, and determine the crack width in combination with the change trend of the strain values in adjacent regions, improving the accuracy of crack identification. It can not only effectively detect the bulge deformation of the formation, but also provide finer-grained crack information for settlement monitoring, making the monitoring results more accurate and enhancing the safety and early warning ability during subway construction.

[0117] Specifically, obtaining the real-time crack width at each bulge within the second temporary region according to the real-time strain values of any two adjacent second temporary regions includes:

[0118] Obtain the distance between the two second temporary regions;

[0119] Calculate the difference between the real-time strain values of the two second temporary regions to form a strain difference;

[0120] Calculate the ratio of the strain difference to the distance to form a strain gradient;

[0121] When the strain gradient is greater than the preset gradient threshold, determine the midpoint of the two second temporary regions as the midpoint of the bulge to form a bulge midpoint;

[0122] Obtain the widths of all cracks within a circular region with the bulge midpoint as the center and a preset bulge length as the radius;

[0123] Calculate the average value of all the widths to form the real-time crack width.

[0124] Among them, obtaining the distance between the two second temporary regions includes:

[0125] It is completed by calculating the Euclidean distance between the center points of these two regions. First, determine the center coordinates of the two second temporary regions according to the grid distribution of the weak grating array sensor. Then, use the Euclidean distance formula to calculate the straight-line distance between the two points, so as to accurately obtain the spatial separation distance between the two temporary regions, providing basic data for further crack width calculation.

[0126] Obtaining the widths of all cracks within a circular area centered at the midpoint of the bulge and with a preset bulge length as the radius is achieved through an ultrasonic sensor. The ultrasonic sensor can accurately detect the presence and size of cracks by emitting high-frequency sound waves and measuring the reflection time of the sound waves. By analyzing the time difference and intensity change of the ultrasonic return signal, the precise width of the crack can be calculated, thus providing reliable crack monitoring data.

[0127] The preset bulge length refers to the standard length for determining the radius of the bulge area when calculating the crack width. It depends on geological conditions, construction impacts, and monitoring accuracy requirements, and is usually set between 10 meters and 30 meters. In this embodiment, it is set to 20 meters, which can effectively cover the bulge influence area generated during the construction process and provide sufficient data for accurately calculating the crack width, ensuring the reliability and accuracy of the monitoring results.

[0128] First, obtain the distance between two adjacent second temporary areas and calculate the difference in their real-time strain values to obtain the strain difference. Calculate the strain gradient by the ratio of the strain difference to the area distance to judge the degree of local deformation. When the strain gradient exceeds the preset gradient threshold, determine the midpoint of the two areas as the midpoint of the bulge. Then, with this midpoint of the bulge as the center and the preset bulge length as the radius, delimit the detection range, obtain the widths of all cracks within the range, and calculate their average value to finally form the real-time crack width.

[0129] Accurately locate the formation position of the bulge through the strain gradient calculation to ensure the accuracy of bulge detection. At the same time, analyze the crack width centered on the bulge to make the crack monitoring range more targeted and improve the reliability of crack width calculation. Combining the deformation characteristics of the local area can timely identify potential hazards that may affect the safety of subway construction and provide more accurate data support for subsequent adjustments and corrections.

[0130] Specifically, adjusting the preset synchronization threshold according to the real-time crack width within a preset adjustment duration to form an adjusted synchronization threshold includes:

[0131] Calculate the standard deviation of the real-time crack width to form the first width fluctuation value;

[0132] When the first width fluctuation value is greater than the preset first width fluctuation threshold, reduce the preset synchronization threshold according to the relative deviation between the crack width fluctuation value and the preset width fluctuation threshold and the preset adjustment coefficient to form the adjusted synchronization threshold, where the relative deviation between the crack width fluctuation value and the preset width fluctuation threshold is positively correlated with the adjusted synchronization threshold.

[0133] The preset first width fluctuation threshold is a standard value used to determine whether the crack width fluctuation is significant. It depends on the environmental characteristics and monitoring requirements of the construction area and is usually set between 0.1 mm and 2 mm. In this embodiment, it is set to 1 mm, which can ensure that abnormal changes can be detected in a timely manner under normal construction vibration and ground settlement, while avoiding false alarms caused by overly sensitive fluctuations.

[0134] The preset adjustment coefficient is a coefficient used to adjust the synchronization threshold when the crack width fluctuation exceeds the threshold. It depends on the response speed and accuracy requirements of the actual monitoring system and is usually set between 0.1 and 0.5. In this embodiment, it is set to 0.2, which can reasonably reduce the synchronization threshold, enabling the system to more sensitively capture potential settlement problems when the crack width changes.

[0135] Within the preset adjustment duration, the first width fluctuation value is obtained by calculating the standard deviation of the real-time crack width. When the crack width fluctuation value is greater than the preset first width fluctuation threshold, the synchronization threshold is reduced according to the relative deviation between the crack width fluctuation value and the preset threshold and the preset adjustment coefficient, thereby forming an adjusted synchronization threshold.

[0136] By dynamically adjusting the preset synchronization threshold, it is possible to flexibly respond to large crack width fluctuations during the construction process, improve the sensitivity and accuracy of monitoring, ensure that small changes in ground settlement and deformation can be captured in a timely manner, and enhance the real-time response ability and monitoring accuracy of the monitoring.

[0137] Specifically, correcting the preset settlement amount threshold according to the number of the second temporary regions determined based on the adjusted synchronization threshold within the preset correction duration to form a corrected settlement amount threshold includes:

[0138] Calculating the standard deviation of the number of the second temporary regions to form a quantity fluctuation value;

[0139] When the quantity fluctuation value is greater than the preset quantity fluctuation threshold, calculating the relative deviation between the quantity fluctuation value and the preset quantity fluctuation threshold to form a quantity fluctuation deviation;

[0140] When the quantity fluctuation deviation is greater than the preset fluctuation deviation threshold, reducing the preset settlement amount threshold according to the relative deviation between the quantity fluctuation deviation and the preset fluctuation deviation threshold and the preset correction coefficient to form a corrected settlement amount threshold, where the relative deviation between the quantity fluctuation deviation and the preset fluctuation deviation threshold and the corrected settlement amount threshold are positively correlated.

[0141] The preset quantity fluctuation threshold refers to the maximum allowable fluctuation of the quantity in the second temporary area within the preset correction duration, which depends on the actual construction conditions and the requirements of settlement monitoring accuracy. It is usually set between 1 and 10. In this embodiment, it is set to 5, which can balance the response to abnormal fluctuations and the need to avoid excessive adjustments, and can promptly reflect obvious settlement changes during the construction process.

[0142] The preset fluctuation deviation threshold refers to the condition for correcting the settlement amount threshold when the quantity fluctuation deviation exceeds this threshold, which depends on the changes in the construction environment and the requirements of the monitoring strategy. It is usually set between 0.1 and 0.5. In this embodiment, it is set to 0.3, which helps to make reasonable adjustments during large fluctuations and avoid frequent adjustments caused by minor fluctuations.

[0143] The preset correction coefficient refers to the coefficient for adjusting the settlement amount threshold based on the quantity fluctuation deviation when correcting the settlement amount threshold, which depends on the accuracy of the monitoring equipment and the sensitivity of the settlement threshold. It is usually set between 0.5 and 2. In this embodiment, it is set to 1.5, which can reasonably adjust the settlement amount threshold and avoid inaccurate monitoring caused by excessive correction.

[0144] First, calculate the standard deviation of the quantity of the second temporary area to form a quantity fluctuation value. When the quantity fluctuation value exceeds the preset quantity fluctuation threshold, calculate the relative deviation between the quantity fluctuation value and the preset threshold to form a quantity fluctuation deviation. When the quantity fluctuation deviation exceeds the preset fluctuation deviation threshold, adjust the preset settlement amount threshold according to the relative deviation between the quantity fluctuation deviation and the preset fluctuation deviation threshold and the preset correction coefficient to form a corrected settlement amount threshold.

[0145] Dynamically adjust the settlement amount threshold according to the actually monitored quantity fluctuation situation of the second temporary area, thereby improving the accuracy of settlement monitoring. When the abnormal settlement fluctuation within the area increases, the threshold can be adjusted in a timely manner to prevent false alarms caused by overly strict thresholds, and at the same time ensure an accurate response to real settlement abnormal events, effectively improving the sensitivity and reliability of monitoring.

[0146] Specifically, determining a plurality of abnormal settlement areas according to the real-time crack width obtained based on the corrected settlement amount threshold within a preset determination duration includes:

[0147] Calculate the standard deviation of the real-time crack width to form a second width fluctuation value;

[0148] When the second width fluctuation value is greater than the preset second width fluctuation threshold, determine the second temporary area where the corresponding circular area is located as the abnormal settlement area to determine a plurality of abnormal settlement areas.

[0149] The preset second width fluctuation threshold is a standard value used to determine whether the crack width fluctuation is abnormal. It depends on the geological characteristics of the construction area, the equipment accuracy, and the monitoring requirements. It is usually set between 0.1 mm and 2 mm. In this embodiment, it is set to 1 mm, which can ensure the monitoring sensitivity while avoiding overly frequent false alarms and improving the practicability and accuracy of the monitoring system.

[0150] By calculating the standard deviation of the real-time crack width, the second width fluctuation value is obtained, and then it is judged whether the fluctuation value exceeds the preset second width fluctuation threshold. If it exceeds the threshold, it is determined that the area is an abnormal settlement area. Through this method, the area where the ground undergoes abnormal settlement can be identified and located, thus ensuring the real-time monitoring and timely adjustment of the construction area.

[0151] Through the analysis of the crack width fluctuation, the abnormal settlement area caused by settlement can be accurately identified, so as to quickly respond to potential construction risks. By setting a reasonable fluctuation threshold, over-sensitive detection can be avoided, ensuring the stability and efficiency of the monitoring system. At the same time, early warnings can be issued in a timely manner, providing an effective basis for subsequent construction adjustments.

[0152] On the other hand, please continue to refer to Figure 4 shown in the figure, which is a schematic diagram of the ground settlement monitoring system based on the weak grating array in this embodiment;

[0153] This embodiment also provides a ground settlement monitoring system based on the weak grating array, including:

[0154] A first acquisition module for acquiring the real-time strain value and the real-time ground settlement amount of each weak grating array acquisition area during the subway shield construction process;

[0155] A first determination module, connected to the first acquisition module, for determining a number of first temporary areas according to the real-time ground settlement amount and the preset settlement amount threshold;

[0156] A second determination module, respectively connected to the first acquisition module and the first determination module, for determining a number of second temporary areas according to the real-time ground settlement amount, the real-time strain value, and the preset synchronization threshold of each of the first temporary areas;

[0157] A second acquisition module, connected to the second determination module, for acquiring the real-time crack width at each bulge in the second temporary area according to the real-time strain value in all the second temporary areas;

[0158] An adjustment module, respectively connected to the second determination module and the second acquisition module, for adjusting the preset synchronization threshold according to the real-time crack width within the preset adjustment duration to form an adjusted synchronization threshold;

[0159] A correction module, which is respectively connected to the first determination module, the adjustment module and the second determination module, and is used to correct the preset settlement amount threshold based on the number of the second temporary regions determined within a preset correction duration to form a corrected settlement amount threshold;

[0160] A third determination module, which is respectively connected to the correction module and the second acquisition module, and is used to determine a plurality of abnormal settlement regions based on the real-time crack width acquired within a preset determination duration based on the corrected settlement amount threshold;

[0161] A prompt module, which is connected to the third determination module, and is used to issue an abnormal prompt according to the abnormal settlement region.

[0162] Through the cooperation of multiple modules, the real-time strain value of the weak grating array and the ground settlement amount during the subway shield construction are firstly acquired. Based on the preset settlement amount threshold, the system determines a plurality of first temporary regions, and then further refines them into second temporary regions according to the synchronization threshold. On this basis, the system calculates the crack width and adjusts the synchronization threshold according to the real-time crack width. By correcting the settlement amount threshold, the system can accurately determine the abnormal settlement regions within a preset duration, and finally issue an abnormal prompt to timely warn of the possible ground settlement problems during the construction process.

[0163] Through the accurate real-time monitoring of the ground settlement, the monitoring parameters can be dynamically adjusted according to the actual data during the construction process, providing more refined abnormal detection. By adjusting the preset synchronization threshold and the preset settlement amount threshold, the system improves the accuracy and flexibility of the monitoring, and avoids the construction safety hazards caused by the failure to detect the settlement problem in time. In addition, the early identification of the abnormal settlement regions can help the relevant personnel take measures quickly, effectively reduce the construction risk, and improve the construction safety.

[0164] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A ground settlement monitoring method based on weak grating array monitoring, characterized in that Including: Obtaining real-time strain values and real-time ground settlement amounts of each weak grating array acquisition area during subway shield construction; Determining a number of first temporary areas according to the real-time ground settlement amount and a preset settlement amount threshold; Determining a number of second temporary areas according to the real-time ground settlement amount, the real-time strain value and a preset synchronization degree threshold of each of the first temporary areas; Obtaining the real-time crack width at each bulge in the second temporary area according to the real-time strain value in all the second temporary areas; Adjusting the preset synchronization degree threshold according to the real-time crack width within a preset adjustment duration to form an adjusted synchronization degree threshold; Correcting the preset settlement amount threshold according to the number of the second temporary areas determined based on the adjusted synchronization degree threshold within a preset correction duration to form a corrected settlement amount threshold; Determining a number of abnormal settlement areas according to the real-time crack width obtained based on the corrected settlement amount threshold within a preset determination duration; Sending an abnormal prompt according to the abnormal settlement area.

2. The ground settlement monitoring method based on weak grating array monitoring according to claim 1, characterized in that Determining a number of first temporary areas according to the real-time ground settlement amount and a preset settlement amount threshold includes: When the real-time ground settlement amount is greater than the preset settlement amount threshold, determining the weak grating array acquisition area as the first temporary area to determine a number of first temporary areas.

3. The ground settlement monitoring method based on weak grating array monitoring according to claim 2, characterized in that, Determining a number of second temporary areas according to the real-time ground settlement amount, the real-time strain value and a preset synchronization degree threshold of each of the first temporary areas includes: Calculating the standard deviation of all the real-time ground settlement amounts within a preset synchronous calculation duration to form a settlement amount fluctuation value; Calculating the standard deviation of all the real-time strain values within the preset synchronous calculation duration to form a strain fluctuation value; Determining a number of second temporary areas according to the settlement amount fluctuation value, the strain fluctuation value and the preset synchronization degree threshold.

4. The ground settlement monitoring method based on weak grating array monitoring according to claim 3, characterized in that, Determining a number of second temporary areas according to the settlement amount fluctuation value, the strain fluctuation value and the preset synchronization degree threshold includes: Drawing a change curve of the settlement amount fluctuation value within the preset synchronous calculation duration to form a settlement fluctuation curve; Drawing a change curve of the strain fluctuation value within the preset synchronous calculation duration to form a strain fluctuation curve; Calculating the cosine similarity of the settlement fluctuation curve and the strain fluctuation curve to form a synchronization degree; When the synchronization degree is less than the preset synchronization degree threshold, determining the first temporary area as the second temporary area to determine a number of second temporary areas.

5. The ground settlement monitoring method based on weak grating array monitoring according to claim 4, characterized in that, Obtaining the real-time crack width at each bulge in the second temporary area according to the real-time strain value in all the second temporary areas includes: Calculating the standard deviation of all the real-time strain values to form a strain distribution value; When the strain distribution value is greater than a preset strain distribution threshold, obtaining the real-time crack width at each bulge in the second temporary area according to the real-time strain values of any two adjacent second temporary areas.

6. The ground settlement monitoring method based on weak grating array monitoring according to claim 5, characterized in that Obtaining the real-time crack width at each bulge in the second temporary area according to the real-time strain values of any two adjacent second temporary areas includes: Obtaining the distance between the two second temporary areas; Calculating the difference between the real-time strain values of the two second temporary areas to form a strain difference; Calculate the ratio of the strain difference to the distance to form a strain gradient; When the strain gradient is greater than a preset gradient threshold, determine the midpoint of the two second temporary regions as the midpoint of the bulge to form a bulge midpoint; Obtain the widths of all cracks within a circular region with the bulge midpoint as the center and a preset bulge length as the radius; Calculate the average value of all the widths to form a real-time crack width; 7. The ground settlement monitoring method based on weak grating array monitoring according to claim 6, characterized in that, Adjust the preset synchronization threshold according to the real-time crack width within a preset adjustment duration to form an adjusted synchronization threshold, including: Calculate the standard deviation of the real-time crack width to form a first width fluctuation value; When the first width fluctuation value is greater than a preset first width fluctuation threshold, reduce the preset synchronization threshold according to the relative deviation between the first width fluctuation value and the preset first width fluctuation threshold and a preset adjustment coefficient to form an adjusted synchronization threshold; 8. The ground settlement monitoring method based on weak grating array monitoring according to claim 7, characterized in that, Correct the preset settlement threshold according to the number of the second temporary regions determined based on the adjusted synchronization threshold within a preset correction duration to form a corrected settlement threshold, including: Calculate the standard deviation of the number of the second temporary regions to form a number fluctuation value; When the number fluctuation value is greater than a preset number fluctuation threshold, calculate the relative deviation between the number fluctuation value and the preset number fluctuation threshold to form a number fluctuation deviation; When the number fluctuation deviation is greater than a preset fluctuation deviation threshold, reduce the preset settlement threshold according to the relative deviation between the number fluctuation deviation and the preset fluctuation deviation threshold and a preset correction coefficient to form a corrected settlement threshold; 9. The ground settlement monitoring method based on weak grating array monitoring according to claim 8, characterized in that, Determine several abnormal settlement regions according to the real-time crack width obtained based on the corrected settlement threshold within a preset determination duration, including: Calculate the standard deviation of the real-time crack width to form a second width fluctuation value; When the second width fluctuation value is greater than a preset second width fluctuation threshold, determine the corresponding circular region as the abnormal settlement region to determine several abnormal settlement regions; 10. A ground settlement monitoring system based on weak grating array monitoring, based on the ground settlement monitoring method based on weak grating array monitoring according to any one of claims 1-9, characterized in that, Including: A first acquisition module for acquiring the real-time strain values and real-time ground settlement amounts of each weak grating array acquisition region during subway shield construction; A first determination module connected to the first acquisition module for determining several first temporary regions according to the real-time ground settlement amount and a preset settlement threshold; A second determination module respectively connected to the first acquisition module and the first determination module for determining several second temporary regions according to the real-time ground settlement amount, the real-time strain value of each first temporary region, and a preset synchronization threshold; A second acquisition module connected to the second determination module for acquiring the real-time crack widths at the bulges in each second temporary region according to the real-time strain values within all the second temporary regions; An adjustment module respectively connected to the second determination module and the second acquisition module for adjusting the preset synchronization threshold according to the real-time crack width within a preset adjustment duration to form an adjusted synchronization threshold; A correction module, which is respectively connected to the first determination module, the adjustment module and the second determination module, and is used to correct the preset settlement amount threshold according to the number of the second temporary regions determined based on the adjustment synchronization threshold within a preset correction duration, so as to form a corrected settlement amount threshold; A third determination module, which is respectively connected to the correction module and the second acquisition module, and is used to determine a number of abnormal settlement regions according to the real-time crack width obtained based on the corrected settlement amount threshold within a preset determination duration; A prompt module, which is connected to the third determination module and is used to send out an abnormal prompt according to the abnormal settlement region.

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