Prefabricated concrete structure safety monitoring method and system using BIM model

Abstract

This invention relates to the field of safety monitoring technology, specifically to a method and system for safety monitoring of prefabricated concrete structures using a BIM model. The method includes: acquiring point cloud data of different prefabricated components; determining mating point pairs based on bidirectional nearest neighbor analysis of the point cloud data on the contact surface; performing contact tightness analysis on the mating point pairs to determine the connection fit; performing surface fitting based on the coordinate position of each mating point to obtain a fitted surface; determining the connection stability based on the distance between the point cloud data on the contact surface and the fitted surface; determining the connection safety factor by combining the connection stability and connection fit; determining the safety monitoring requirement based on the change in the connection safety factor at different sampling times; and performing safety monitoring based on the safety monitoring requirement. This invention can effectively analyze the mutual influence of the overall structure and improve the safety monitoring effect.

Description

Technical Field

[0001] This invention relates to the field of safety monitoring technology, specifically to a method and system for safety monitoring of prefabricated concrete structures using BIM models. Background Technology

[0002] Prefabricated concrete structures are a method of assembling precast concrete components on-site. This method offers fast construction speed, high production efficiency, and reduced material waste, making it a promising option. However, because the precast components are directly assembled, they have significant inter-component influence. If one component is damaged or destroyed, the other connected components will be greatly affected. Therefore, this type of structure is highly susceptible to cascading collapses, resulting in substantial losses of resources and casualties. Thus, rigorous safety monitoring of prefabricated concrete structures is necessary to ensure timely repair and protection before collapse occurs, preventing further damage.

[0003] Currently, safety monitoring of prefabricated concrete structures often employs BIM model construction. In realistic simulations, safety monitoring is conducted by observing the deformation and damage of individual prefabricated components, with a focus on components experiencing severe deformation and damage. However, because prefabricated concrete structural components are interconnected and mutually influential, monitoring safety solely based on the damage of a single prefabricated component neglects the overall structural interactions, resulting in ineffective safety monitoring. Summary of the Invention

[0004] To address the technical problem of poor safety monitoring results due to the tendency to overlook the mutual influence of the overall structure in related technologies, this invention provides a safety monitoring method and system for prefabricated concrete structures using BIM models. The specific technical solution adopted is as follows:

[0005] This invention proposes a safety monitoring method for prefabricated concrete structures using BIM models, the method comprising:

[0006] At each sampling moment, point cloud data of different prefabricated components are acquired from the BIM model of the prefabricated concrete building.

[0007] On the contact surface of two precast components, bidirectional nearest neighbor analysis is performed based on the point cloud data of the two precast components to determine the matching mating point pairs; the contact tightness is determined by combining the distance distribution between the two points in all mating point pairs; and the connection fit is determined by combining the proportion of the number of mating point pairs on the contact surface and the contact tightness.

[0008] Based on the coordinate positions of the two points in the BIM model for each bonding point pair, determine the center position point of the bonding point pair; perform surface fitting on all center position points to obtain the fitted surface; determine the connection stability based on the distance between the point cloud data on the contact surface and the fitted surface.

[0009] The connection safety factor is determined by combining the connection stability and connection fit of the two precast components; the safety monitoring requirement of the precast component is determined based on the change of the connection safety factor between the precast component and the precast component in contact at different sampling times, and safety monitoring is carried out based on the safety monitoring requirement.

[0010] Furthermore, the step of performing bidirectional nearest neighbor analysis based on the point cloud data of the two prefabricated components to determine matching mating point pairs includes:

[0011] The point cloud datasets on the contact surface of the two precast components are determined as follows: and Extract any point from each point cloud dataset to form an analysis point pair (p, q), where p is... In the point cloud data, q is Point cloud data in;

[0012] In q is The point closest to p in the interval, and p is... When the point is closest to q, the analysis point pair (p, q) is determined as the bidirectional nearest neighbor and is used as the fitting point pair.

[0013] Furthermore, determining the contact tightness by combining the distance distribution between the two centers of all contact points includes:

[0014] Calculate the Euclidean distance between the two points at each fitting point in the BIM model, and use it as the fitting distance;

[0015] Determine the median of the contact distance between all contact point pairs on the contact surface, and normalize the negative of the median as the contact tightness.

[0016] Furthermore, the degree of connection fit is determined by the proportion of the number of bonding point pairs to the contact surface and the contact tightness, including:

[0017] The proportion of the number of mating points to the center points in the total number of point cloud data on the contact surface of the two prefabricated components is used as the point cloud matching degree.

[0018] The product of contact tightness and point cloud matching degree is normalized and used as the connection fit degree.

[0019] Further, determining the center position point of the bonding point pair based on the coordinate positions of the two points in the BIM model for each bonding point pair includes:

[0020] The midpoint of the coordinates of the two points in the BIM model for each bonding point pair is taken as the center point of the bonding point pair.

[0021] Further, the step of performing surface fitting on all center position points to obtain the fitted surface includes:

[0022] The fitted surface is obtained by using local weighted regression.

[0023] Furthermore, determining the connection stability based on the distance between the point cloud data on the contact surface and the fitted surface includes:

[0024] Calculate the point-to-surface distances between all contact surface point cloud data and the fitted surface, and use this distance as the point-to-surface distance;

[0025] Calculate the mean of the point-to-surface distance, and normalize the negative of the mean as the connection stability.

[0026] Furthermore, the determination of the connection safety factor by combining the connection stability and connection fit of the two prefabricated components includes:

[0027] Based on preset safety weights, the connection stability and connection fit of the contact surfaces of the two prefabricated components are weighted and summed, and then normalized to obtain the connection safety coefficient.

[0028] Furthermore, determining the safety monitoring requirement of the precast component based on the change in the connection safety factor between the precast component and the precast component in contact at different sampling times includes:

[0029] A two-dimensional rectangular coordinate system is constructed with any prefabricated component as the target component, the connection safety factor as the vertical axis, and the sampling time as the horizontal axis.

[0030] In a two-dimensional rectangular coordinate system, determine the coordinate points of the target component and another prefabricated component in contact with it at all sampling times, and perform straight line fitting to obtain the fitting slope;

[0031] The normalized value of the inverse of the fitting slope of the target component and the prefabricated component in contact with each phase is calculated and used as the weight of the time series variation.

[0032] The product of the temporal change weight and the connection safety factor at the current sampling time is calculated, and the negative of the product is normalized to serve as the connection anomaly degree between the target component and the corresponding prefabricated component in contact.

[0033] The maximum value of the connection anomaly between the target component and each prefabricated component in contact with the phase is taken as the safety monitoring requirement.

[0034] On the other hand, a safety monitoring system for prefabricated concrete structures utilizing a BIM model is also provided. The system includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of the method as described in any of the foregoing.

[0035] The present invention has the following beneficial effects:

[0036] This invention acquires point cloud data of different prefabricated components from a BIM model. Then, based on bidirectional nearest neighbor analysis of the point cloud data on the contact surfaces between two prefabricated components, it identifies mating point pairs. Combining the overall distribution of these mating point pairs, it determines the connection fit, which characterizes the degree of fit between the two prefabricated components. Next, it performs standard mating curve fitting on the mating point pairs to obtain a fitted curve, and analyzes the connection stability based on the interval between the actual point cloud data and the fitted curve. Both the connection fit and connection stability are analyzed based on the relationship between the two prefabricated components. By integrating the characteristics of these two dimensions, a connection safety factor is obtained, characterizing the safety index under mutual contact conditions. Then, based on the temporal change of the connection safety factor, it determines the safety monitoring requirement of the prefabricated components, and performs safety monitoring based on this requirement. In summary, compared to the existing technology that analyzes the deformation of each prefabricated component to achieve safety monitoring, this invention focuses on analyzing the mutual changes in contact between different prefabricated components, thereby effectively analyzing the mutual influence of the overall structure and improving the safety monitoring effect. Attached Figure Description

[0037] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 A flowchart illustrating a safety monitoring method for prefabricated concrete structures using a BIM model, provided as an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of sleeve grouting reinforcement provided in one embodiment of the present invention. Detailed Implementation

[0040] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a safety monitoring method and system for prefabricated concrete structures utilizing a BIM model proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0041] Unless otherwise defined, 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 invention pertains.

[0042] The following description, in conjunction with the accompanying drawings, details a specific scheme for a safety monitoring method for prefabricated concrete structures using a BIM model, provided by this invention.

[0043] Please see Figure 1 The diagram illustrates a flowchart of a safety monitoring method for prefabricated concrete structures using a BIM model, according to an embodiment of the present invention. The method includes:

[0044] S101: At each sampling time, acquire point cloud data of different prefabricated components on the BIM model of the prefabricated concrete building.

[0045] Prefabricated concrete structures are a method of assembling precast concrete components on-site. This method offers fast construction speed, high production efficiency, and reduced material waste, making it a promising option. However, because the precast components are directly assembled, they have significant inter-component influence. If one component is damaged or destroyed, the other connected components will be greatly affected. Therefore, this type of structure is highly susceptible to cascading collapses, resulting in substantial losses of resources and casualties. Thus, rigorous safety monitoring of prefabricated concrete structures is necessary to ensure timely repair and protection before collapse occurs, preventing further damage.

[0046] Currently, safety monitoring of prefabricated concrete structures often employs BIM (Building Information Modeling) to create models. In realistic simulations, safety monitoring is conducted by observing the damage to individual prefabricated components, with a focus on severely damaged parts. However, because prefabricated concrete structural components are interconnected and mutually influential, monitoring safety based solely on the damage of a single component can overlook the overall structural relationships, resulting in ineffective safety monitoring.

[0047] In this embodiment of the invention, for the prefabricated concrete building to be monitored, three-dimensional scanning can be performed at different sampling times to obtain point cloud data, which is then mapped into a three-dimensional model to obtain a BIM model. Specifically, the surface point cloud data of the actual components on site are acquired using a "three-dimensional laser scanner, photogrammetry, or displacement sensor" and registered into the three-dimensional coordinate system of the BIM model. The specific methods are well known to those skilled in the art and will not be elaborated further.

[0048] S102: On the contact surface of two precast components, perform bidirectional nearest neighbor analysis based on the point cloud data of the two precast components to determine the matching mating point pairs; combine the distance distribution between the two points in all mating point pairs to determine the contact tightness; combine the proportion of the number of mating point pairs on the contact surface and the contact tightness to determine the connection fit.

[0049] In order to support the main structure of a building, different prefabricated components will come into contact with each other, and there will be mutual forces on the contact surfaces. Therefore, the contact areas are prone to breakage and deterioration, leading to the risk of cascading collapse. Therefore, this embodiment of the invention analyzes two contacting prefabricated components. First, it is necessary to determine their contact surfaces. The two prefabricated components are connected to each other through nodes and seams to form the overall structure. The areas where the prefabricated components are connected show a higher degree of fit compared to other areas. Their shapes are undulating and have a certain degree of conformity to achieve a better connection effect. Therefore, point cloud matching is performed, and then the degree of fit is analyzed.

[0050] Furthermore, in some embodiments of the present invention, determining matching mating point pairs by performing bidirectional nearest neighbor analysis based on the point cloud data of two prefabricated components includes: determining the point cloud datasets on the contact surfaces of the two prefabricated component point cloud data as follows: and Extract any point from each point cloud dataset to form an analysis point pair (p, q), where p is... In the point cloud data, q is Point cloud data in q; The point closest to p in the interval, and p is... When the point is closest to q, the analysis point pair (p, q) is determined as the bidirectional nearest neighbor and is used as the fitting point pair.

[0051] Wherein, bidirectional nearest neighbor means that two points are the nearest neighbors of another point. In this embodiment of the invention, the two points also belong to different point cloud datasets, that is, to different prefabricated components. A point p in the first prefabricated component is the closest point to the second prefabricated component in the spatial range, which is point q. At the same time, the closest point to point q in the first prefabricated component is point p. At this time, (p, q) can become a bidirectional nearest neighbor relationship, and the point pair (p, q) is analyzed as a fitting point pair.

[0052] It should be noted that the bonding point pair represents the pair of points corresponding to the positions on the contact surface. By analyzing the distance between them, the degree of bonding between the two prefabricated components can be analyzed. In this embodiment of the invention, the contact tightness is used to characterize the degree of bonding.

[0053] Furthermore, in some embodiments of the present invention, the contact tightness is determined by combining the distance distribution between the two points in all mating point pairs, including: calculating the Euclidean distance between the two points in each mating point pair in the BIM model as the mating distance; determining the median of the mating distances of all mating point pairs on the contact surface, and normalizing the negative of the median as the contact tightness.

[0054] The BIM model is a three-dimensional model. To facilitate analysis, this embodiment of the invention analyzes the distance between the two points in the BIM model and determines the Euclidean distance between the two points in the BIM model as the bonding distance. The larger the bonding distance value, the larger the gap between the two points. Therefore, the median of the bonding distance of all bonding point pairs on the contact surface is used as the overall feature, and the negative of the median is calculated and normalized to obtain the contact tightness.

[0055] In one embodiment of the present invention, the normalization process can be specifically, for example, maximum and minimum value normalization. Furthermore, the normalization in subsequent steps can all adopt maximum and minimum value normalization. In other embodiments of the present invention, other normalization methods can be selected according to the specific range of the numerical values, which will not be elaborated further.

[0056] It should be noted that, for ease of calculation, all indicator data involved in the calculation in this embodiment of the invention have undergone data preprocessing to eliminate the influence of dimensions. The specific methods for eliminating the influence of dimensions are well known to those skilled in the art and are not limited here.

[0057] It should be noted that in some other embodiments of the present invention, the mean of the centering and bonding distance of all bonding points can also be calculated, and the negative of the mean can be normalized as the contact tightness. However, since the mean is affected by extremely large and small outliers, it is not as representative as the median in actual analysis. Therefore, the median feature is preferred.

[0058] The outlines of the two prefabricated components fit together, with points facing each other, resulting in a high utilization rate of the fitting area and a tighter fit between them.

[0059] Furthermore, in some embodiments of the present invention, the connection fit is determined by combining the proportion of the number of mating point pairs in the contact surface and the contact tightness, including: taking the proportion of the number of midpoints of the mating point pairs in the total number of point cloud data of the contact surface of the two prefabricated components as the point cloud matching degree; and normalizing the product of the contact tightness and the point cloud matching degree as the connection fit.

[0060] For example, if the first prefabricated component has 100 point cloud data points on its surface and the second prefabricated component has 200 point cloud data points on its surface, then there are a total of 300 point cloud data points. If there are 50 mating point pairs, then the number of midpoints in each mating point pair is 100. In this case, the point cloud matching degree is the ratio of 100 to 300. It should be noted that both contact tightness and point cloud matching degree are dimensionless data and both represent the connection and mating characteristics of the two prefabricated components. The larger the value, the tighter the mating. Therefore, the product of contact tightness and point cloud matching degree is directly calculated and normalized to obtain the connection fit degree. The larger the connection fit degree value, the more uniform and tight the contact surface spacing between the contours of the two prefabricated components, and the stronger the relative connection between them.

[0061] S103: Determine the center point of each bonding point pair based on the coordinates of the two points in the BIM model; perform surface fitting on all center points to obtain the fitted surface; determine the connection stability based on the distance between the point cloud data on the contact surface and the fitted surface.

[0062] Connection fit characterizes the degree of fit between two prefabricated components. If the two prefabricated components are only tightly fitted, they may not be able to strongly connect with each other to ensure that no deformation occurs. There still needs to be a certain structure between them so that they can be tightly connected and interact with each other so that they are not easy to be separated by reverse operation after they are connected.

[0063] like Figure 2 As shown, Figure 2 This is a schematic diagram of sleeve grouting reinforcement provided in one embodiment of the present invention. Sleeve grouting technology is used to reinforce and compact the connection between two components, making them more robust, stable, and safe. Before sleeve grouting, it is necessary to further assess the connection stability between the two precast components in the connection area.

[0064] The sleeve grouting technology requires an assessment of the gap between the contact surfaces. Therefore, in this embodiment of the invention, the center point position of the two points of the bonding point in the BIM model is first analyzed.

[0065] Furthermore, in some embodiments of the present invention, determining the center position point of the bonding point pair based on the coordinate positions of the two points of each bonding point pair in the BIM model includes: taking the midpoint of the coordinates of the two points of each bonding point pair in the BIM model as the center position point of the bonding point pair.

[0066] If we assume that the coordinates of the two points at the center of the mating point are (1,1,1) and (1,5,9) respectively, then the midpoint of the corresponding coordinates represents the average value of the coordinates on the same axis, that is, the midpoint of the coordinates is (1,3,5).

[0067] Because the two prefabricated components have different shapes, such as being designed as mortise and tenon joints or other shapes for coupling, direct analysis based on shape will lead to the neglect of various morphological features. However, regardless of the shape, the smaller the joint between the two prefabricated components, the tighter and more stable the connection. Therefore, analysis can be based on the center point position.

[0068] First, surface fitting is performed on all center points to obtain the fitted surface, including: surface fitting based on local weighted regression to obtain the fitted surface.

[0069] Local weighted regression is a technique well-known to those skilled in the art, and no limitation is imposed on it. Based on the local weighted regression method, it is possible to perform surface fitting by combining all center position points, and the resulting fitted surface represents the fitted standard surface of the two prefabricated components under the condition of tight bonding without tolerance.

[0070] It is understandable that there is a corresponding contact surface between the two prefabricated components, which represents the overlapping area between the two prefabricated components. The aforementioned fitted surface represents the standard shape of the contact surface. Therefore, the connection stability can be visually represented based on the interval between the point cloud data of the contact surface and the standard fitted surface.

[0071] Furthermore, in some embodiments of the present invention, determining the connection stability based on the distance between the point cloud data on the contact surface and the fitted surface includes: calculating the point-to-surface distance between all the point cloud data on the contact surface and the fitted surface as the point-to-surface distance; calculating the mean of the point-to-surface distance, and normalizing the negative of the mean as the connection stability.

[0072] In this embodiment of the invention, the point cloud data of the contact surface is a point, and the fitted surface is a surface. The distance between the point cloud data and the fitted surface can be calculated based on the point-to-surface distance formula. Since both prefabricated components have corresponding point cloud data on the contact surface, the average point-to-surface distance between all the contact surface point cloud data and the fitted surface is calculated. The larger the value of the average, the farther the distance between the point cloud data and the fitted surface, which means that the connection on the contact surface is less stable. The negative value of the average is normalized as the connection stability.

[0073] It should be noted that, in the embodiments of the present invention, the connection stability represents the connection stability of the two prefabricated components on the contact surface. The larger the value, the smaller the overall gap between the two prefabricated components on the contact surface, and the more stable the connection.

[0074] S104: Determine the connection safety factor by combining the connection stability and connection fit of the two precast components; determine the safety monitoring requirement of the precast component based on the change of the connection safety factor between the precast component and the precast component in contact at different sampling times, and carry out safety monitoring based on the safety monitoring requirement.

[0075] Since connection stability indicates the stability of the connection between two prefabricated components at the contact surface, a larger value indicates a smaller overall gap between the two prefabricated components at the contact surface, and a more stable connection. Similarly, connection fit indicates the degree of fit between the two prefabricated components during connection; a larger value indicates a more uniform and tighter spacing between the contact surfaces of the two prefabricated components, and a stronger relative connection. Therefore, based on these characteristics, the connection safety factor can be analyzed at the same sampling time.

[0076] Furthermore, in some embodiments of the present invention, the connection safety factor is determined by combining the connection stability and connection fit of the two prefabricated components, including: weighting and summing the connection stability and connection fit of the contact surfaces of the two prefabricated components based on preset safety weights, and then normalizing the sum to obtain the connection safety factor.

[0077] It should be noted that in actual analysis, connection stability and connection fit can be configured with different reference weights. For example, the weight of connection stability can be 0.4 and the weight of connection fit can be 0.6. Then, the product of 0.4 and connection stability is calculated, and the product of 0.6 and connection fit is calculated. The two products are added together and normalized to obtain the connection safety factor.

[0078] The specific weight values ​​given in the embodiments of this invention (such as 0.4, 0.6, etc.) are empirical values ​​obtained under typical hardware configurations and test scenarios, intended to facilitate understanding of this invention. In practical applications, those skilled in the art can adjust, calibrate, or optimize these parameters according to specific hardware performance, scenario complexity, and data characteristics, which does not constitute a limitation of this invention.

[0079] The connection security factor represents the security analysis achieved by combining the two parameters of connection stability and connection fit. The higher the value of the connection security factor, the safer and more reliable the connection.

[0080] Over time, components may be damaged by external environmental factors and their own stress, leading to changes in the connections between components. At this time, the external shape and internal structure of the contact surface will change, and the corresponding connection stability and connection fit will also change. The time sequence analysis of this change can be used to obtain the safety monitoring requirements.

[0081] Furthermore, in some embodiments of the present invention, the safety monitoring requirement of a precast component is determined based on the change in the connection safety factor between the precast component and the precast component in contact with it at different sampling times. This includes: taking any precast component as the target component and constructing a two-dimensional rectangular coordinate system with the connection safety factor as the vertical axis and the sampling time as the horizontal axis; in the two-dimensional rectangular coordinate system, determining the coordinate points corresponding to the target component and another precast component in contact with it at all sampling times, and performing linear fitting to obtain the fitting slope; calculating the normalized value of the inverse of the fitting slope between the target component and each precast component in contact with it, as the time-series change weight; calculating the product of the time-series change weight and the connection safety factor corresponding to the current sampling time, normalizing the inverse of the product value, and using it as the connection anomaly degree between the target component and the corresponding precast component in contact with it; and taking the maximum value of the connection anomaly degree between the target component and each precast component in contact with it as the safety monitoring requirement.

[0082] The connection safety factor changes over time. Under objective conditions, its value will gradually decrease, indicating that the connection is becoming increasingly unstable and weak. The degree of change in its value indicates the degree of need for safety monitoring.

[0083] First, a two-dimensional rectangular coordinate system is constructed with the connection safety factor as the vertical axis and the sampling time as the horizontal axis. Then, the overall change analysis is achieved by fitting the straight lines of the coordinate points corresponding to the target component and another prefabricated component in contact with it at all sampling times.

[0084] The smaller the slope of the fitted straight line, the greater the deterioration of the safety of the phase contact. Therefore, the normalized value of the inverse of the fitted slope of the target component and each prefabricated component in phase contact is calculated as the weight of the time-series change. The larger the value of the weight of the time-series change, the smaller the degree of reduction of the connection safety factor in time and the lower the overall deterioration level.

[0085] In order to analyze the current sampling time, it is also necessary to combine the connection safety factor at the current sampling time, calculate the product of the temporal change weight and the connection safety factor at the corresponding current sampling time, and normalize the negative of the product value as the connection anomaly degree between the target component and the corresponding prefabricated component in contact.

[0086] Among them, the connection anomaly degree indicates the degree of anomaly at the contact surface between the target component and the corresponding prefabricated component. The larger the value, the lower the stability and fit of the contact surface between the target component and the corresponding prefabricated component, and thus the more abnormal the overall connection state, the greater the probability of damage, and the more necessary it is to conduct safety monitoring to prevent collapse.

[0087] It should be noted that both the time-series variation weights and the connectivity safety coefficients are dimensionless data, which can be used for calculation and analysis.

[0088] Since the target component can be connected to one or more other prefabricated components, in order to achieve more timely and accurate analysis results, the maximum value of the connection anomaly degree between the target component and the prefabricated component in contact with each phase is taken as the safety monitoring requirement degree.

[0089] In other words, the greater the safety monitoring requirement, the more safety monitoring is needed for the target component and the prefabricated components it comes into contact with. In this embodiment of the invention, the monitoring level of the prefabricated component can be directly divided according to the value of the safety monitoring requirement of each prefabricated component. For example, it can be divided into three value ranges: [0, 0.5], (0.5, 0.8], and (0.8, 1]. When the safety monitoring requirement is in the range of [0, 0.5], it indicates a low monitoring requirement, requiring only routine maintenance. When it is in the range of (0.5, 0.8], it indicates a medium monitoring requirement, requiring timely repair. When it is in the range of (0.8, 1], it indicates a high monitoring requirement, requiring component replacement.

[0090] The above example is one possible implementation. It should be understood that in other embodiments of the present invention, different dimensions of monitoring effects can be achieved by using the numerical value of the safety monitoring demand level. The higher the value of the safety monitoring demand level, the higher the level of safety monitoring required. For example, relevant personnel may be notified to pay close attention to the corresponding components and take timely maintenance and protection measures to avoid progressive collapse.

[0091] This invention acquires point cloud data of different prefabricated components from a BIM model. Then, based on bidirectional nearest neighbor analysis of the point cloud data on the contact surfaces between two prefabricated components, it identifies mating point pairs. Combining the overall distribution of these mating point pairs, it determines the connection fit, which characterizes the degree of fit between the two prefabricated components. Next, it performs standard mating curve fitting on the mating point pairs to obtain a fitted curve, and analyzes the connection stability based on the interval between the actual point cloud data and the fitted curve. Both the connection fit and connection stability are analyzed based on the relationship between the two prefabricated components. By integrating the characteristics of these two dimensions, a connection safety factor is obtained, characterizing the safety index under mutual contact conditions. Then, based on the temporal change of the connection safety factor, it determines the safety monitoring requirement of the prefabricated components, and performs safety monitoring based on this requirement. In summary, compared to the existing technology that analyzes the deformation of each prefabricated component to achieve safety monitoring, this invention focuses on analyzing the mutual changes in contact between different prefabricated components, thereby effectively analyzing the mutual influence of the overall structure and improving the safety monitoring effect.

[0092] On the other hand, a safety monitoring system for prefabricated concrete structures utilizing a BIM model is also provided. The system includes a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of the safety monitoring method for prefabricated concrete structures utilizing a BIM model as described in any of the preceding claims.

[0093] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0094] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for safety monitoring of prefabricated concrete structures using BIM models, characterized in that, The method includes: At each sampling moment, point cloud data of different prefabricated components are acquired from the BIM model of the prefabricated concrete building. On the contact surface of two precast components, bidirectional nearest neighbor analysis is performed based on the point cloud data of the two precast components to determine the matching mating point pairs; the contact tightness is determined by combining the distance distribution between the two points in all mating point pairs; and the connection fit is determined by combining the proportion of the number of mating point pairs on the contact surface and the contact tightness. Based on the coordinate positions of the two points in the BIM model for each bonding point pair, determine the center position point of the bonding point pair; perform surface fitting on all center position points to obtain the fitted surface; determine the connection stability based on the distance between the point cloud data on the contact surface and the fitted surface. The connection safety factor is determined by combining the connection stability and connection fit of the two precast components; the safety monitoring requirement of the precast component is determined based on the change of the connection safety factor between the precast component and the precast component in contact at different sampling times, and safety monitoring is carried out based on the safety monitoring requirement.

2. The method for safety monitoring of prefabricated concrete structures using BIM models as described in claim 1, characterized in that, The step of performing bidirectional nearest neighbor analysis based on the point cloud data of two prefabricated components to determine matching mating point pairs includes: The point cloud datasets on the contact surface of the two precast components are determined as follows: and Extract any point from each point cloud dataset to form an analysis point pair (p, q), where p is... In the point cloud data, q is Point cloud data in; In q is The point closest to p in the interval, and p is... When the point is closest to q, the analysis point pair (p, q) is determined as the bidirectional nearest neighbor and is used as the fitting point pair.

3. The method for safety monitoring of prefabricated concrete structures using BIM models as described in claim 1, characterized in that, The determination of contact tightness by combining the distance distribution between the two centers of all contact points includes: Calculate the Euclidean distance between the two points at each fitting point in the BIM model, and use it as the fitting distance; Determine the median of the contact distance between all contact point pairs on the contact surface, and normalize the negative of the median as the contact tightness.

4. The method for safety monitoring of prefabricated concrete structures using BIM models as described in claim 1, characterized in that, The degree of fit is determined by the proportion of the number of bonding points to the contact surface and the contact tightness, including: The proportion of the number of mating points to the center points in the total number of point cloud data on the contact surface of the two prefabricated components is used as the point cloud matching degree. The product of contact tightness and point cloud matching degree is normalized and used as the connection fit degree.

5. The method for safety monitoring of prefabricated concrete structures using BIM models as described in claim 1, characterized in that, Determining the center position of the bonding point pair based on the coordinate positions of the two points in the BIM model for each bonding point pair includes: The midpoint of the coordinates of the two points in the BIM model for each bonding point pair is taken as the center point of the bonding point pair.

6. The method for safety monitoring of prefabricated concrete structures using BIM models as described in claim 1, characterized in that, The process of fitting a surface to all center points to obtain a fitted surface includes: The fitted surface is obtained by using local weighted regression.

7. The method for safety monitoring of prefabricated concrete structures using BIM models as described in claim 1, characterized in that, The determination of connection stability based on the distance between the point cloud data on the contact surface and the fitted surface includes: Calculate the point-to-surface distances between all contact surface point cloud data and the fitted surface, and use this distance as the point-to-surface distance; Calculate the mean of the point-to-surface distance, and normalize the negative of the mean as the connection stability.

8. The method for safety monitoring of prefabricated concrete structures using BIM models as described in claim 1, characterized in that, The determination of the connection safety factor by combining the connection stability and connection fit of the two prefabricated components includes: Based on preset safety weights, the connection stability and connection fit of the contact surfaces of the two prefabricated components are weighted and summed, and then normalized to obtain the connection safety coefficient.

9. A method for safety monitoring of prefabricated concrete structures using BIM models as described in claim 1, characterized in that, The determination of the safety monitoring requirement for precast components based on the change in the connection safety factor between the precast components and the precast components in contact with each other at different sampling times includes: A two-dimensional rectangular coordinate system is constructed with any prefabricated component as the target component, the connection safety factor as the vertical axis, and the sampling time as the horizontal axis. In a two-dimensional rectangular coordinate system, determine the coordinate points of the target component and another prefabricated component in contact with it at all sampling times, and perform straight line fitting to obtain the fitting slope; The normalized value of the inverse of the fitting slope of the target component and the prefabricated component in contact with each phase is calculated and used as the weight of the time series variation. The product of the temporal change weight and the connection safety factor at the current sampling time is calculated, and the negative of the product is normalized to serve as the connection anomaly degree between the target component and the corresponding prefabricated component in contact. The maximum value of the connection anomaly between the target component and each prefabricated component in contact with the phase is taken as the safety monitoring requirement.

10. A safety monitoring system for prefabricated concrete structures using a BIM model, the system comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method as described in any one of claims 1 to 9.

Images