A stress monitoring and analysis method for prefabricated pier-cap beam

Abstract

The present application relates to the field of stress monitoring technology, and specifically to a stress monitoring and analysis method for prefabricated assembled pier-cap beams, the method comprising: collecting real-time stress data at the connection between the pier and the cap beam, and real-time displacement data on the surface of the cap beam; obtaining each abnormal time period corresponding to the stress and each abnormal time period corresponding to the displacement respectively; calculating the deviation abnormality of the pier-cap beam at the current moment; determining the abnormal coupling index of the pier-cap beam at the current moment; determining the stress distribution coefficient of the pier-cap beam at the current moment; obtaining the additional stress influence of the pier-cap beam at the current moment, and real-time monitoring of the potential deformation risk at the connection between the pier and the cap beam. The present application provides an early warning of the stress distribution state inside the structure, improves the accuracy of judging the changes in the stress state inside the structure, prevents the weak links of the structure from causing cracks that lead to the destruction of the structure, and improves the stability of the pier-cap beam structure.

Description

Technical Field

[0001] The present application relates to the technical field of stress monitoring, and in particular to a stress monitoring and analysis method for a prefabricated assembled pier column-cap beam. Background Art

[0002] With the economic growth and the need for infrastructure construction, bridge construction technology continues to advance. By prefabricating piers and cap beams in factories and then assembling them on site, it not only improves construction efficiency but also reduces the impact on the environment. In order to ensure the safety and stability of these structures during construction and use, the stress and displacement changes during construction are monitored to evaluate the safety of the structure and to detect potential structural problems in a timely manner, thereby ensuring the long-term stable operation of the bridge.

[0003] Concrete is injected into the prefabricated piers and cap beams for connection. During the hardening process of concrete, it will be affected by environmental factors such as temperature and humidity, resulting in uneven stress distribution inside the concrete, which will cause shrinkage and creep. Over time, the internal structure of the bridge will deform. These changes are not easy to observe directly, and conventional stress detection methods can often only detect the surface or near-surface conditions of concrete, making it difficult to accurately assess internal creep and shrinkage. Therefore, these internal changes may cause the stress state and durability of the structure to gradually deteriorate without being noticed, affecting the accurate judgment of the changes in the internal stress state of the structure, and further affecting the assessment of the internal stability of the pier-cap beam structure. Summary of the invention

[0004] In order to solve the above technical problems, a stress monitoring and analysis method for a prefabricated assembled pier-cap beam is provided to solve the existing problems.

[0005] The solution to the technical problem of the present application is to provide a stress monitoring and analysis method for a prefabricated pier column-cap beam, comprising the following steps:

[0006] Collect real-time stress data at the connection between pier column and cap beam, and real-time displacement data on the cap beam surface;

[0007] Analyze the abnormal random fluctuations of all stress data and displacement data before the current moment, and obtain each abnormal time period corresponding to stress and each abnormal time period corresponding to displacement;

[0008] Analyze the duration of each abnormal period corresponding to stress and displacement, as well as the average deviation of all monitoring data in each abnormal period corresponding to stress and displacement, and calculate the deviation abnormality of the pier column-cap beam at the current moment;

[0009] The abnormal coupling index of the pier column-cap beam at the current moment is determined by the time synchronization degree of abnormal changes in the abnormal periods corresponding to stress and displacement, combined with the quantitative difference of abnormal periods of stress and displacement, and the degree of deviation abnormality;

[0010] Analyze the extreme values ​​of all stress data before the current moment, as well as the deviation of the average level of all stress data in the local period at the moment corresponding to the extreme value, the quantitative proportion of stress data deviation in the local period, and determine the stress distribution coefficient of the pier column-cap beam at the current moment in combination with the discrete degree of all stress data in the local period;

[0011] By integrating the abnormal coupling index and the stress distribution coefficient, the additional stress influence of the pier column and the cap beam at the current moment is obtained, and the potential deformation risk of the connection between the pier column and the cap beam is monitored in real time.

[0012] Preferably, the step of respectively obtaining each abnormal time period corresponding to the stress and each abnormal time period corresponding to the displacement includes:

[0013] Record stress and displacement as monitoring parameters, perform trend decomposition on the monitoring data of any monitoring parameter at all times before the current time, and obtain the residual term;

[0014] Anomaly detection is performed on the residual item of any of the monitoring parameters, the moment corresponding to the abnormal residual is recorded as the abnormal moment, and the time period formed by the consecutive abnormal moments is recorded as each abnormal time period of any of the monitoring parameters.

[0015] Preferably, the calculation of the deviation anomaly of the pier column-cap beam at the current moment includes:

[0016] For any of the monitoring parameters, calculate the ratio of the duration of each abnormal period to the total duration of all abnormal periods, recorded as the abnormal duration ratio; calculate the ratio between the mean of all monitoring data in each abnormal period and the mean of monitoring data at all times before the current time, recorded as the abnormal offset;

[0017] The sum of the products of the abnormal duration ratio and the abnormal offset in all abnormal time periods is calculated, and the cumulative sum of the sum of all monitoring parameters is taken as the deviation abnormality of the pier column-cap beam at the current moment.

[0018] Preferably, the time synchronization degree is: counting the number of all moments before the current moment, recorded as the time acquisition amount; calculating the ratio of the number of abnormal moments with the same stress and displacement to the time acquisition amount, recorded as the time synchronization degree.

[0019] Preferably, the determining of the abnormal coupling index of the pier column-cap beam at the current moment includes:

[0020] The quantitative differences between stress and displacement in all abnormal time periods are calculated, and the ratio of the time synchronization degree to the quantitative difference is recorded as the coupling abnormality; the product of the coupling abnormality and the deviation abnormality is used as the abnormal coupling index of the pier-cap beam at the current moment.

[0021] Preferably, the process of obtaining the local time period is: obtaining the minimum value of all stress data before the current moment; recording multiple moments in the neighborhood of the moment corresponding to any minimum value as the local time period of the moment corresponding to any minimum value.

[0022] Preferably, the degree of discreteness is the information entropy of stress data at all times in each local time period.

[0023] Preferably, the determining of the stress distribution coefficient of the pier column-cap beam at the current moment includes:

[0024] Calculate the average value of stress data at all times before the current time; calculate the difference between the mean value of all stress data in each local time period and the average value, and record it as the local deviation; multiply the local deviation by the discrete degree, and record it as the stress fluctuation degree;

[0025] Calculate the ratio of the number of stress data greater than the average value to the time acquisition amount in each local time period, and record it as the local time ratio;

[0026] The sum of the ratios of the stress fluctuation degree and the local time length ratio in all local time periods is taken as the stress distribution coefficient of the pier-cap beam at the current moment.

[0027] Preferably, the additional stress influence degree is a normalized result of the product of the abnormal coupling index and the stress distribution coefficient.

[0028] Preferably, the real-time monitoring of the potential deformation risk at the connection between the pier and the cap beam includes: if the additional stress influence degree at the current moment is greater than a preset threshold, there is a potential deformation risk at the connection between the pier and the cap beam; otherwise, there is no potential deformation risk at the connection between the pier and the cap beam.

[0029] This application has at least the following beneficial effects:

[0030] The present application decomposes trends and performs an abnormal analysis on the random fluctuations of stress data and displacement data, eliminates the interference of changes in trend and seasonal factors, screens out abnormal periods of random fluctuations of residual terms, analyzes the duration of abnormal conditions in different abnormal periods, and the degree of deviation of stress and displacement in the abnormal period, and calculates the degree of deviation abnormality. The beneficial effect of this application is that it takes into account the duration of abnormal stress and displacement at the connection between the pier and the cap beam, as well as the degree of abnormality. The application calculates the abnormal coupling index through the time synchronization of abnormal stress and displacement, which has the beneficial effect of reflecting the degree of coupling and influence of abnormal changes in stress and displacement caused by the aging effect of creep and shrinkage. The application determines the degree of deviation of stress by analyzing the local period of the minimum point of stress change, analyzing the deviation of stress data in the local period, and the degree of discreteness of stress data. The beneficial effect of the distribution coefficient is that it takes into account the complex situation of stress state changes at the connection between the cap beam and the pier column caused by the combined effect of creep and shrinkage, so as to reflect the influence of the additional stress caused by creep and shrinkage on the structure, calculate the influence of additional stress, and monitor the potential deformation risk of the connection between the pier column and the cap beam in real time. The beneficial effect of the distribution coefficient is that it takes into account the influence of additional stress caused by the aging effect of creep and shrinkage of concrete, and explains the dynamic changes of the internal stress state of the component structure under long-term load and its influence on the stability of the structure; by monitoring the stress at the connection between the pier column and the cap beam in real time, it is possible to timely warn of the stress distribution state inside the structure, improve the accuracy of the judgment of the changes in the stress state inside the structure, prevent the weak links of the structure from causing cracks and causing the structure to be damaged, and improve the stability of the pier-cap beam structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The following is a further detailed description of a stress monitoring and analysis method for a prefabricated assembled pier-cap beam of the present application in conjunction with the accompanying drawings.

[0032] Figure 1 A flowchart of the steps of a stress monitoring and analysis method for a prefabricated assembled pier column-cap beam provided in an embodiment of the present application;

[0033] Figure 2 A flowchart of the steps of a method for obtaining an abnormal coupling index of a pier column and a cap beam at the current moment provided in an embodiment of the present application;

[0034] Figure 3 A flowchart of the steps of a method for obtaining the stress distribution coefficient of a pier column-cap beam at the current moment provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of this application more clear, the following is a further detailed description of a stress monitoring and analysis method for a prefabricated assembled pier-cap beam proposed in this application in combination with the accompanying drawings and implementation examples. It should be understood that the specific embodiments described here are only used to explain this application and are not used to limit this application.

[0036] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0037] See also Figure 1 , which shows a flowchart of a stress monitoring and analysis method for a prefabricated pier column-cap beam provided by an embodiment of the present application, the method comprising the following steps:

[0038] Step 1: Collect real-time stress data at the pier-cap beam connection and real-time displacement data on the cap beam surface.

[0039] Traditional bridge construction mostly uses cast-in-place concrete construction technology, with many wet operations on site, long construction period, great impact on the surrounding environment, poor working conditions, high energy consumption and low efficiency. Compared with traditional cast-in-place bridges, prefabricated assembly construction can speed up construction, save resources and energy, reduce environmental interference with construction, reduce the impact of construction on the environment, and improve construction quality and safety level. During the construction of prefabricated bridges, whether the structural force can meet the design requirements will affect whether the bridge can be safely constructed and successfully accepted to a certain extent. Therefore, it is necessary to monitor the status of the bridge structure in real time.

[0040] During the process of tying the steel cage and after the concrete is poured, the concrete will shrink in volume during the hardening process, and under the action of continuous stress, the concrete will undergo plastic deformation over time. This shrinkage and deformation may cause displacement of the connection parts between the prefabricated components during the installation process, and stress changes will occur. Therefore, stress sensors are installed at the connection between the pier and the cap beam to collect stress data in real time, and displacement sensors are installed on the surface of the cap beam at the connection between the pier and the cap beam to collect displacement data of the cap beam in real time. The collected data are normalized, thereby obtaining the stress data of the connection between the pier and the cap beam at each moment, as well as the displacement data of the cap beam at each moment.

[0041] In this embodiment, the acquisition frequency of the sensor is set to 50 Hz. As other implementation methods, the implementer can set it according to the actual situation. Secondly, the maximum and minimum normalization method is used for normalization processing. Among them, the maximum and minimum normalization method is a well-known technology and will not be described here.

[0042] At this point, the stress data of the connection between the pier and the cap beam at each time, as well as the displacement data of the cap beam at each time, are obtained.

[0043] Step 2, analyze the abnormal random fluctuations of all stress data and displacement data before the current moment, and obtain each abnormal time period corresponding to stress and each abnormal time period corresponding to displacement respectively; analyze the duration proportion of each abnormal time period corresponding to stress and displacement, and the deviation of the average level of all monitoring data in each abnormal time period corresponding to stress and displacement, and calculate the deviation abnormality of the pier column-cap beam at the current moment; determine the abnormal coupling index of the pier column-cap beam at the current moment through the degree of time synchronization of abnormal changes in the abnormal time periods corresponding to stress and displacement, combined with the difference in the number of abnormal time periods of stress and displacement, and the deviation abnormality.

[0044] Creep refers to the phenomenon that the strain of a material increases over time under constant stress, while shrinkage refers to the phenomenon that the volume of a material decreases during cooling or drying. Both are manifestations of the material aging process. The combined effect of creep and shrinkage will cause the coupling relationship between stress and displacement to become more complicated. For example, creep causes stress redistribution, while shrinkage causes new tensile stress. The combined effect of the two will cause nonlinear changes in displacement data, and the long-term effects of creep and shrinkage will cause gradual changes in structural performance, and its stress data and displacement data will show long-term trend changes. Therefore, both creep and shrinkage will cause abnormal changes in stress and displacement between the pier and the cap beam, and abnormal changes in stress or displacement will reduce the structural bearing capacity and stability of bridge construction.

[0045] Based on the above analysis, the abnormal degree of change of stress data and displacement data, as well as the synchronization of abnormal changes of stress data and displacement data are analyzed, and the abnormal coupling index is calculated. The step flow chart of the method for obtaining the abnormal coupling index of the pier column-cap beam at the current moment provided in this embodiment is as follows: Figure 2 As shown, specifically including:

[0046] The stress data and displacement data are recorded as monitoring parameters, and the monitoring data of any monitoring parameter at all times before the current time are subjected to trend decomposition to obtain the residual term;

[0047] In this embodiment, the STL (Seasonal and Trend decomposition using Loess) trend decomposition algorithm is used to perform trend decomposition to obtain a residual term, wherein the STL trend decomposition algorithm is a well-known technology and will not be described in detail herein.

[0048] Performing anomaly detection on the residual item of any of the monitoring parameters, recording the time corresponding to the abnormal residual as the abnormal time, and recording the time period formed by the consecutive abnormal moments as each abnormal time period of any of the monitoring parameters;

[0049] In this embodiment, the interquartile range (IQR) of the residual term of any monitoring parameter is calculated, wherein the first quartile is recorded as Q1, the second quartile is recorded as Q2, and the third quartile is recorded as Q3. , will not be distributed in The residuals within the range are regarded as abnormal residuals, and the corresponding moments of the abnormal residuals are recorded as abnormal moments.

[0050] It should be noted that the residual term reflects the random fluctuations in the monitoring data after removing the influence of trend and seasonal changes, and can better reflect the abnormal changes in stress and displacement between the pier and the cap beam.

[0051] For any of the monitoring parameters, calculate the ratio of the duration of each abnormal period to the total duration of all abnormal periods, which is recorded as the abnormal duration ratio;

[0052] Calculate the ratio between the mean of all monitoring data in each abnormal period and the mean of monitoring data at all times before the current time, and record it as the abnormal offset;

[0053] Calculate the sum of the products of the abnormal duration ratio and the abnormal offset in all abnormal time periods, and record the cumulative sum of the sums of all monitoring parameters as the deviation abnormality of the pier column-cap beam at the current moment;

[0054] It should be noted that, the larger the abnormal time ratio is, the longer the duration of the abnormal change in stress or displacement at the connection between the pier and the cap beam is; the larger the abnormal offset is, the greater the degree to which the monitoring data of stress or displacement in the corresponding abnormal period deviates from the average level, and the larger the deviation abnormality is, the longer the abnormal stress and displacement at the connection between the pier and the cap beam will last, as well as the degree of the abnormality.

[0055] Count the number of all moments before the current moment, and record it as the time collection amount; calculate the ratio of the number of the same abnormal moments among all monitoring parameters to the time collection amount, and record it as the time synchronization degree;

[0056] Calculate the quantitative differences of all abnormal time periods between all monitoring parameters, and record the ratio of the time synchronization degree to the quantitative difference as the coupling abnormality; multiply the coupling abnormality by the deviation abnormality as the abnormal coupling index of the pier column-cap beam at the current moment;

[0057] In this embodiment, the absolute value of the difference between stress and displacement for the number of all abnormal periods is calculated.

[0058] It should be noted that, the greater the degree of time synchronization, the more synchronous the abnormal changes of stress and displacement are, and the greater the influence of the coupling of stress and displacement on the aging performance of the connection between the pier and the cap beam; the greater the quantity difference, the greater the frequency difference of the abnormal changes of stress and displacement at the connection between the pier and the cap beam, and the lower the synchronization of stress and displacement. The abnormal coupling index reflects the coupling degree and influence range of the abnormal changes of stress and displacement caused by the aging effects such as creep and shrinkage of concrete at the connection between the pier and the cap beam. The larger the abnormal coupling index, the greater the coupling influence of the aging effects of stress and displacement on the structural performance.

[0059] So far, the abnormal coupling index of pier column-cap beam at the current moment.

[0060] Step 3, analyze the extreme values ​​of all stress data before the current moment, as well as the deviation of the average level of all stress data in the local time period corresponding to the extreme value, the quantitative proportion of stress data deviation in the local time period, and determine the stress distribution coefficient of the pier-cap beam at the current moment in combination with the degree of discreteness of all stress data in the local time period.

[0061] Furthermore, for the connection between the cap beam and the pier, creep may lead to stress redistribution, so that the stress in the original stress concentration area is relieved to a certain extent, but it may also cause stress increase in other areas. Shrinkage will cause tensile stress inside the concrete, which can easily cause concrete cracking. The combined effect of creep and shrinkage may cause the stress state of the connection between the cap beam and the pier to become more complicated.

[0062] Based on the above analysis, the shrinkage of concrete will cause additional tensile stress to be generated inside, thereby affecting the magnitude of stress and causing stress changes to become more complicated. The effects of creep and shrinkage will gradually appear over time, which makes the changes in stress state dynamic and complex. Secondly, due to the influence of creep, the internal stress of the structure is redistributed, so that the stress in the original stress concentrated area is continuously relieved, which manifests as a local stress reduction. Therefore, the minimum point of the stress data is the turning point of the stress change. In the process of stress redistribution, the originally concentrated stress will gradually disperse to other areas. The minimum point is the beginning of this dispersion process, because the stress has been reduced to a relatively low level at this time. The minimum point is locally analyzed and the stress distribution coefficient is calculated. The step flow chart of the method for obtaining the stress distribution coefficient of the pier-cap beam at the current moment provided in this embodiment is as follows: Figure 3 As shown, specifically including:

[0063] Obtain the minimum value of all stress data before the current moment; record multiple moments in the neighborhood of a moment corresponding to any minimum value as a local period of the moment corresponding to any minimum value;

[0064] In this embodiment, the minimum value is obtained by the difference method, and all moments within 1 minute in the neighborhood of the moment corresponding to any minimum value are recorded as local time periods. As other implementation methods, the implementers can set them according to actual conditions.

[0065] Calculate the average value of stress data at all times before the current time; calculate the difference between the mean value of all stress data in each local time period and the average value, and record it as the local deviation;

[0066] In this embodiment, the absolute value of the difference between the mean value of all stress data in each local time period and the average value is calculated and recorded as the local deviation;

[0067] Calculate the ratio of the number of stress data greater than the average value to the time acquisition amount in each local time period, and record it as the local time ratio;

[0068] Calculate the information entropy of all stress data in each local time period;

[0069] It should be noted that the calculation of information entropy is a well-known technology and will not be described in detail here.

[0070] The product of the local deviation and the discrete degree is recorded as the stress fluctuation degree; the sum of the ratios of the stress fluctuation degree and the local time length ratio in all local time periods is taken as the stress distribution coefficient of the pier column-cap beam at the current moment;

[0071] In this embodiment, the calculation method of the stress distribution coefficient of the pier column-cap beam at the current moment is: ,in, For the pier-cap beam at the current moment The stress distribution coefficient, For the The local deviation of a local period, For the The information entropy of all stress data in a local period is For the The local duration ratio of the local time period, For the current moment The number of local time periods corresponding to all the minimum values ​​of .

[0072] It should be noted that the local deviation reflects the degree of stress change in the local time period. The larger the local deviation, the more likely it is that stress redistribution will occur inside the concrete, indicating that the influence of additional stress is more significant; the local time length ratio reflects the degree to which the stress in the local time period is lower than the average level. If stress redistribution occurs, the stress in the original stress concentration area will be reduced. However, the larger the local time length ratio, the larger the stress distribution in the local time period, and the smaller the possibility of stress redistribution in the concrete; the larger the information entropy, the more complex the stress change in the local time period, reflecting that the local area where stress redistribution occurs is more likely to be affected by shrinkage at the same time; the larger the stress distribution coefficient, the greater the influence of additional stress caused by creep and shrinkage on the structure.

[0073] At this point, the stress distribution coefficient of the pier-cap beam at the current moment is obtained.

[0074] Step 4, integrating the abnormal coupling index and the stress distribution coefficient to obtain the additional stress influence of the pier column and cap beam at the current moment, and monitoring the potential deformation risk of the connection between the pier column and the cap beam in real time.

[0075] Further, based on the abnormal coupling index and the stress distribution coefficient, the additional stress influence is determined, specifically:

[0076] The normalized result of the product of the abnormal coupling index and the stress distribution coefficient is used as the additional stress influence degree of the pier column-cap beam at the current moment;

[0077] In this embodiment, the sigmoid function is used for normalization processing, wherein the sigmoid function is a well-known technology and will not be described in detail here. As other implementation methods, the implementer can adopt other methods of the prior art, such as the tanh function, etc. This embodiment does not impose any special restrictions on this.

[0078] It should be noted that the abnormal coupling index reflects the coupling degree of abnormal changes in stress and displacement caused by aging effects such as creep and shrinkage of concrete at the connection between the pier and the cap beam. The larger the abnormal coupling index, the more significant the impact of the aging effect on the structural performance, which will lead to greater structural deformation or stress redistribution, thereby affecting the safety and durability of the structure. The stress distribution coefficient reflects the degree of influence of the additional stress generated by the creep and shrinkage of concrete at the connection between the pier and the cap beam on the structure. The larger the stress distribution coefficient, the greater the influence of the additional stress generated by the creep and shrinkage on the structure. The additional stress influence degree reflects the degree of influence of the additional stress caused by the aging effect of creep and shrinkage of concrete at the connection between the pier and the cap beam, which indicates the dynamic changes of the internal stress state of concrete under long-term loads. The larger the additional stress influence degree, the greater the dynamic changes of the internal stress state of the component structure under long-term loads, and it is more likely to have problems such as stress concentration and cracking, thereby affecting the stability of the structure.

[0079] Furthermore, through the above analysis, the additional stress caused by creep and shrinkage at the connection between the pier and the cap beam leads to local stress concentration. Because it does not show a significant increase in the overall stress, but occurs inside the structure, it is not easy to be detected in conventional monitoring. This local stress concentration will cause cracks in the weak links of the structure and even destroy the stability of the structure. Therefore, the additional stress at the connection between the pier and the cap beam is monitored in real time, specifically:

[0080] If the additional stress impact degree at the current moment is greater than the preset threshold, there is a potential deformation risk at the connection between the pier and the cap beam, and the additional stress caused by creep and shrinkage is very likely to lead to local stress concentration, thereby causing cracks and deformation in the weak links of the structure, and even causing the structure to be destroyed. Therefore, a real-time warning is given by issuing an early warning signal. Otherwise, there is no potential deformation risk at the connection between the pier and the cap beam, and no early warning signal is issued.

[0081] In this embodiment, the preset threshold value is 0.8. As for other implementation modes, the implementer can set it according to the actual situation.

[0082] By sending out early warning signals in real time, construction workers are reminded to check whether there are any problems in the connection and installation of piers and cap beams, so as to prevent cracks from occurring in weak links of the structure.

[0083] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0084] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the present application. It should be pointed out that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the content of the technical solution of the present application, shall fall within the protection scope of the technical solution of the present application.

Claims

1. A stress monitoring and analysis method for prefabricated pier column-cap beam, characterized in that: The method comprises the following steps: Collect real-time stress data at the connection between pier column and cap beam, and real-time displacement data on the cap beam surface; Analyze the abnormal random fluctuations of all stress data and displacement data before the current moment, and obtain each abnormal time period corresponding to stress and each abnormal time period corresponding to displacement; Analyze the duration of each abnormal period corresponding to stress and displacement, as well as the average deviation of all monitoring data in each abnormal period corresponding to stress and displacement, and calculate the deviation abnormality of the pier column-cap beam at the current moment; Calculate the quantitative differences between stress and displacement in all abnormal periods, obtain the time synchronization degree, and record the ratio of the time synchronization degree to the quantitative difference as the coupling abnormality; multiply the coupling abnormality by the deviation abnormality as the abnormal coupling index of the pier column-cap beam at the current moment; Count the number of all moments before the current moment, recorded as the time collection amount; calculate the average value of the stress data of all moments before the current moment; calculate the difference between the mean value of all stress data in each local time period and the average value, recorded as the local deviation; multiply the local deviation by the degree of dispersion, recorded as the stress fluctuation; calculate the ratio of the number of stress data greater than the average value to the time collection amount in each local time period, recorded as the local time length ratio; take the sum of the ratios between the stress fluctuation and the local time length ratio of all local time periods as the stress distribution coefficient of the pier-cap beam at the current moment; By integrating the abnormal coupling index and the stress distribution coefficient, the additional stress influence of the pier column and the cap beam at the current moment is obtained, and the potential deformation risk of the connection between the pier column and the cap beam is monitored in real time.

2. A stress monitoring and analysis method for a prefabricated pier column-cap beam as claimed in claim 1, characterized in that: The step of respectively obtaining each abnormal time period corresponding to the stress and each abnormal time period corresponding to the displacement includes: Record stress and displacement as monitoring parameters, perform trend decomposition on the monitoring data of any monitoring parameter at all times before the current time, and obtain the residual term; Anomaly detection is performed on the residual item of any of the monitoring parameters, the moment corresponding to the abnormal residual is recorded as the abnormal moment, and the time period formed by the consecutive abnormal moments is recorded as each abnormal time period of any of the monitoring parameters.

3. A stress monitoring and analysis method for a prefabricated pier column-cap beam as claimed in claim 2, characterized in that: The calculation of the deviation anomaly of the pier column-cap beam at the current moment includes: For any of the monitoring parameters, calculate the ratio of the duration of each abnormal period to the total duration of all abnormal periods, recorded as the abnormal duration ratio; calculate the ratio between the mean of all monitoring data in each abnormal period and the mean of monitoring data at all times before the current time, recorded as the abnormal offset; The sum of the products of the abnormal duration ratio and the abnormal offset in all abnormal time periods is calculated, and the cumulative sum of the sum of all monitoring parameters is taken as the deviation abnormality of the pier column-cap beam at the current moment.

4. A stress monitoring and analysis method for a prefabricated pier column-cap beam as claimed in claim 2, characterized in that: The time synchronization degree is: the ratio of the number of times the abnormal moments between the calculated stress and displacement are the same to the time acquisition amount, which is recorded as the time synchronization degree.

5. A stress monitoring and analysis method for a prefabricated pier column-cap beam as claimed in claim 1, characterized in that: The process of obtaining the local time period is as follows: obtaining the minimum value of all stress data before the current moment; and recording multiple moments in the neighborhood of a moment corresponding to any minimum value as the local time period of the moment corresponding to any minimum value.

6. A method for monitoring and analyzing stress of a prefabricated pier column-cap beam as claimed in claim 1, characterized in that: The discrete degree is the information entropy of the stress data at all times in each local time period.

7. A method for monitoring and analyzing stress of a prefabricated pier column-cap beam as claimed in claim 4, characterized in that: The stress distribution coefficient of the pier column-cap beam at the current moment includes: Calculate the average value of stress data at all times before the current time; calculate the difference between the mean value of all stress data in each local time period and the average value, and record it as the local deviation; multiply the local deviation by the discrete degree, and record it as the stress fluctuation degree; Calculate the ratio of the number of stress data greater than the average value to the time acquisition amount in each local time period, and record it as the local time ratio; The sum of the ratios of the stress fluctuation degree and the local time length ratio in all local time periods is taken as the stress distribution coefficient of the pier-cap beam at the current moment.

8. A method for monitoring and analyzing stress of a prefabricated pier column-cap beam as claimed in claim 1, characterized in that: The additional stress influence degree is a normalized result of the product of the abnormal coupling index and the stress distribution coefficient.

9. A method for monitoring and analyzing stress of a prefabricated pier column-cap beam as claimed in claim 1, characterized in that: The real-time monitoring of the potential deformation risk at the connection between the pier and the cap beam includes: if the additional stress influence degree at the current moment is greater than a preset threshold, there is a potential deformation risk at the connection between the pier and the cap beam; otherwise, there is no potential deformation risk at the connection between the pier and the cap beam.

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