A method and system for old building reconstruction design based on BIM and real-time monitoring

Abstract

The application relates to the technical field of urban renewal digital operation and maintenance, and discloses an old building reconstruction design method and system based on BIM and real-time monitoring, which collects three-dimensional point cloud data and nondestructive testing data of an old building to establish an initial BIM model; a sensor is deployed to collect structure response data and establish a mapping association with corresponding components in the initial BIM model; multi-period structure response data is acquired, the structure response parameter variation trend of each component is extracted, and a health state time sequence atlas of each component is generated; a component evaluation system is established based on the health state time sequence atlas, and a reconstruction design scheme is generated; real-time structure response data is continuously collected during the construction process, and when the real-time data deviates from the expected variation trend, the evaluation classification and scheme generation are re-executed to update the reconstruction design scheme and feed back to the construction end. The BIM model dynamic evolution and design scheme closed-loop correction are realized, and the accuracy and safety of the old building reconstruction design are improved.

Description

Technical Field

[0001] This invention relates to the field of digital operation and maintenance technology for urban renewal, and in particular to a design method and system for the renovation of old buildings based on BIM and real-time monitoring. Background Technology

[0002] As urbanization shifts from incremental expansion to stock optimization, the renovation and upgrading of old buildings and communities has become a crucial aspect of smart city construction. These renovation projects often involve multiple stages, including structural reinforcement, spatial restructuring, and interior decoration. A common challenge they face is that the buildings to be renovated were mostly constructed in the 1980s and 1990s, and original design drawings and as-built documentation are often missing or significantly inconsistent with the actual site conditions. Furthermore, after decades of service and multiple renovations, the actual geometric dimensions, component spatial locations, and pipeline routes of the buildings have deviated significantly from the original drawings, and some load-bearing components also exhibit material aging and hidden defects. These factors necessitate that renovation designs cannot rely on existing drawings and must be based on on-site measurements. However, traditional design methods often employ manual measurement combined with two-dimensional drafting, which is not only inefficient and inaccurate but also fails to fully grasp the building's true condition, easily leading to a disconnect between design and construction, subsequently causing changes, rework, and even structural safety accidents.

[0003] To address these issues, Building Information Modeling (BIM) technology has been introduced into the field of old building renovation. BIM models are generated through reverse modeling using 3D laser scanning, providing a visual data foundation for renovation designs. However, existing BIM models are static, reflecting only the physical state of a building at a specific moment and unable to update automatically as construction progresses. Meanwhile, IoT-based structural health monitoring technology has been gradually applied in engineering practice, collecting real-time structural response data by deploying strain and displacement sensors at key locations. However, in actual projects, there is a lack of effective data fusion mechanisms between the monitoring system and the BIM model: on the one hand, monitoring data is often presented as independent reports or graphs, making it difficult to accurately correspond to specific components in the BIM model; on the other hand, monitoring data is only used as a post-construction safety assessment basis. When parameters are abnormal, on-site work often has to be passively halted or empirical measures taken, rather than rapidly and quantitatively correcting the design based on the latest monitoring data. This information gap between the monitoring and design ends prevents the BIM model from dynamically evolving based on real-time data, and the design scheme cannot achieve closed-loop adjustments based on the actual structural response.

[0004] Therefore, there is an urgent need to provide a method and system that can deeply integrate BIM models with real-time monitoring data to achieve dynamic optimization and closed-loop correction of old building renovation designs, so as to effectively solve the technical problems of static BIM models and the separation between monitoring and design in existing technologies, and improve the accuracy, safety and adaptability of old building renovation designs. Summary of the Invention

[0005] The purpose of this invention is to provide a design method and system for the renovation of old buildings based on BIM and real-time monitoring, which solves the problems in the prior art such as static BIM models, the separation between monitoring data and BIM models, and the inability of design schemes to be dynamically adjusted in a closed loop according to the actual structural response during construction.

[0006] To achieve the above objectives, this invention provides a design method for the renovation of old buildings based on BIM and real-time monitoring, comprising the following steps: Collect 3D point cloud data and non-destructive testing data of the old building, and build an initial BIM model of the old building based on the collected data; Sensors are deployed at multiple structural locations in the old building to collect structural response data in real time. The structural response data collected by each sensor is then mapped and associated with the corresponding component in the initial BIM model. Obtain multi-phase structural response data at different time points, compare and analyze the multi-phase structural response data according to the time series, extract the changing trend of structural response parameters of each component in the time dimension, and generate a health status time series map of each component based on the changing trend; Based on the aforementioned health status time series map, a component evaluation system covering safety indicators, durability indicators, and functional integrity indicators is established. Each component in the old building is evaluated and classified according to the component evaluation system, and a renovation design scheme for the old building is generated by combining the renovation needs and constraints. During the renovation of old buildings, real-time structural response data from various sensors are continuously collected. The real-time structural response data is compared with the health status time series map. When the real-time structural response data deviates from the expected trend in the health status time series map, the component evaluation and classification and renovation scheme generation are re-executed based on the current real-time structural response data to update the renovation design scheme. The updated renovation design scheme is then fed back to the construction end.

[0007] This includes collecting 3D point cloud data and non-destructive testing data of the old building, and establishing an initial BIM model of the old building based on the collected data, specifically including: A 3D laser scanner was used to perform a full-area scan of the old building to obtain 3D point cloud data of the interior and exterior of the old building. At least one of the following methods was used to collect the exterior image data of the old building: drone aerial photography and close-range photogrammetry. Non-destructive testing equipment was used to obtain material strength data and steel reinforcement distribution data for each component of the old building. The collected 3D point cloud data, appearance image data, material strength data and steel reinforcement distribution data are denoised, registered and fused. Inverse fitting is performed in BIM software to construct an initial BIM model containing building geometry, structural component information and pipeline network information. The initial BIM model is compared and verified with the on-site measured data, and components with deviations exceeding a preset threshold are corrected.

[0008] Sensors are deployed in multiple structural locations within the old building, specifically including: Sensors were deployed in load-bearing walls, beam-column joints, slotted walls in the proposed renovation area, open floor slabs in the proposed renovation area, and areas with known cracks or settlement defects. The deployed sensors include a variety of strain sensors, displacement sensors, crack gauges, vibration sensors, temperature sensors, and humidity sensors. Each sensor forms a self-organizing sensor network through a wireless communication module. After the structural response data collected by the sensors is acquired and preprocessed in real time through an edge computing gateway, it is uploaded to the system platform via 5G communication or industrial Ethernet.

[0009] Specifically, establishing a mapping relationship between the structural response data collected by each sensor and the corresponding component in the initial BIM model includes: Acquire the spatial coordinate information of each sensor, match the spatial coordinate information with the spatial coordinates of each component in the initial BIM model, and establish the correspondence between the sensor and the component; Each component in the initial BIM model is assigned a unique identifier, and the structural response data collected by each sensor is labeled with the corresponding component unique identifier and timestamp and then stored in the system platform.

[0010] Specifically, the changing trend of the structural response parameters of each component over time is taken, including: Acquire at least one of the strain data, displacement data, crack width data, and vibration data of the same component at different time points, arrange the acquired data in chronological order, and generate time series curves for each monitoring parameter; Based on the time series curve, a trend analysis algorithm is used to calculate the rate of change and cumulative change of each monitoring parameter; Based on the rate of change and the cumulative amount of change, a health state time series map is generated for each component. The health state time series map includes the stress-strain state, deformation offset, crack propagation rate and vibration response characteristics of each component at each time point.

[0011] This includes establishing a component evaluation system that covers safety indicators, durability indicators, and functional integrity indicators, specifically including: Based on the stress monitoring data and remaining material strength of each component in its current state, the bearing capacity margin of the component under the current load and the expected construction load is calculated, and the bearing capacity margin is used as the quantitative value of the safety index. Based on the crack propagation rate and material degradation rate of each component, the remaining service life of the component is calculated, and the remaining service life is used as a quantitative value of the durability index. Based on the displacement and vibration data of each component, the degree of impact of the component on the normal use function of the building is calculated, and the degree of impact is used as the quantitative value of the functional integrity index. The quantitative values ​​of the safety index, durability index, and functional integrity index are weighted and combined to obtain the comprehensive evaluation score for each component.

[0012] Specifically, each component in the old building is evaluated and classified according to the component evaluation system, and a renovation design scheme for the old building is generated by combining the renovation needs and constraints, including: When the overall evaluation score of a component is higher than the first preset threshold, the component will be marked as a component to be retained and utilized. When the comprehensive evaluation score of a component is between the first preset threshold and the second preset threshold, the component is marked as a component to be reinforced and modified, and a corresponding reinforcement scheme is matched from the preset reinforcement measure library based on the specific damage type of the component. When the overall evaluation score of a component is lower than the second preset threshold, the component will be marked as a replacement component. Based on the marking results of each component and the proposed changes to the spatial area and functional configuration in the renovation requirements, the scope of renovation and renovation measures are determined, and a preliminary renovation design scheme including structural reinforcement scheme and construction sequence is generated. The preliminary renovation design scheme is presented in three-dimensional visualization in the initial BIM model.

[0013] Specifically, comparing the real-time structural response data with the health status time series graph includes: Extract the expected range of structural response parameters of each component at the current time node from the health status time series graph, and compare the real-time collected structural response data with the expected range. When the duration of the real-time collected structural response data exceeding the expected value range exceeds a preset time threshold, it is determined that the real-time structural response data deviates from the expected trend.

[0014] Specifically, when the real-time structural response data deviates from the expected trend, it includes: The system platform issues an early warning signal and replaces the historical data of previous time nodes with the real-time structural response data collected at the current moment, and recalculates the health status time sequence map of each component; Based on the updated health status time series map, the component evaluation classification and modification scheme generation are re-executed to obtain the updated modification design scheme; The updated renovation design scheme is compared with the currently implemented renovation design scheme to generate a design change instruction; The design change instruction is pushed to the construction end, and the initial BIM model is updated simultaneously.

[0015] A BIM-based and real-time monitoring-based old building renovation design system includes a data acquisition module, a model building module, a sensor network module, a data fusion module, an evaluation and design module, and a dynamic correction module. The data acquisition module is connected to the model building module, the model building module is connected to the data fusion module, the sensor network module is connected to the data fusion module, the data fusion module is connected to the evaluation and design module, the evaluation and design module is connected to the dynamic correction module, and the dynamic correction module is connected to the evaluation and design module, the sensor network module, and the model building module. The data acquisition module is used to collect three-dimensional point cloud data and non-destructive testing data of the old building, and send the collected data to the model building module; The model building module is used to build an initial BIM model of the old building based on the three-dimensional point cloud data and non-destructive testing data, and send the initial BIM model to the data fusion module. The sensor network module includes multiple sensors deployed at multiple structural locations of the old building. The sensors are used to collect structural response data in real time and upload the structural response data to the data fusion module via a wireless communication network. The data fusion module is used to establish a mapping relationship between the structural response data collected by each sensor and the corresponding component in the initial BIM model, and to organize the structural response data of each sensor according to the time series to generate a health status time series map of each component containing multiple monitoring data, and send the health status time series map to the evaluation and design module. The assessment and design module is used to establish a component assessment system covering safety indicators, durability indicators and functional integrity indicators based on the health status time series map. According to the component assessment system, each component in the old building is assessed and classified, and a renovation design scheme is generated in combination with renovation needs and constraints. The renovation design scheme is then sent to the dynamic correction module. The dynamic correction module is used to receive real-time structural response data uploaded by the sensor network module during the renovation of old buildings, compare the real-time structural response data with the expected change trend in the health status time series map, and trigger the evaluation design module to regenerate an updated renovation design scheme based on the current real-time structural response data when the real-time structural response data deviates from the expected change trend. The updated renovation design scheme is then fed back to the construction end and the model building module to update the initial BIM model.

[0016] This invention discloses a BIM-based and real-time monitoring-based design method and system for the renovation of old buildings. An initial BIM model is established by collecting 3D point cloud data and non-destructive testing data of the old building. Sensors are deployed at key structural parts of the old building to construct an Internet of Things (IoT) monitoring network. Structural response data collected by each sensor is spatially mapped and associated with corresponding components in the initial BIM model. Based on this, multi-period structural response data is acquired, and the changing trends of structural response parameters of each component are extracted according to time series, thereby generating a health status time series map for each component. Furthermore, a component evaluation system covering safety, durability, and functional integrity indicators is established. After evaluating and classifying each component, a renovation design scheme is generated based on renovation requirements and constraints. During the renovation construction process, real-time structural response data is continuously collected and compared with the expected changing trends in the health status time series map. When the real-time data deviates from the expected trend, the evaluation system is automatically recalculated to update the renovation design scheme, and the updated scheme is fed back to the construction end while simultaneously updating the initial BIM model. Thus, this invention realizes the dynamic evolution of the BIM model with the construction process, the accurate mapping and deep integration between monitoring data and the BIM model, and the closed-loop iterative correction of the design scheme based on the actual structural response, effectively improving the accuracy, safety and adaptability of old building renovation design. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0018] Figure 1 This is a flowchart of the steps of the old building renovation design method based on BIM and real-time monitoring according to the first embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the old building renovation design system based on BIM and real-time monitoring according to the second embodiment of the present invention.

[0020] In the diagram: 201-Data Acquisition Module, 202-Model Building Module, 203-Sensor Network Module, 204-Data Fusion Module, 205-Evaluation and Design Module, 206-Dynamic Correction Module. Detailed Implementation

[0021] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0022] First embodiment: Please refer to Figure 1 This invention provides a BIM-based and real-time monitoring-based design method for the renovation of old buildings, comprising the following steps: S101: Collect 3D point cloud data and non-destructive testing data of the old building, and establish an initial BIM model of the old building based on the collected data; Specifically, a 3D laser scanner is first used to perform a full-area scan of the old building, acquiring 3D point cloud data of its interior and exterior. The 3D laser scanner emits a laser beam and receives signals reflected from the building surface to obtain the coordinate information of each point on the building surface in 3D space. Because a single scan may have obstructions or blind spots, multiple scanning stations need to be set up around the exterior of the building and on each floor inside to ensure that the scanning range covers all structural components and spatial areas of the building. The scanning data from each station needs to be registered using targets or feature points to achieve spatial coordinate unification of the cloud data from multiple stations. Simultaneously, drone aerial photography is used to collect images of the old building's roof and facade from an aerial perspective. For narrow areas or indoor spaces that drones cannot access, close-range photogrammetry is used to collect supplementary image data. This image data can not only be used for texture mapping during subsequent 3D modeling, improving the model's visual effect and recognizability, but also help verify the integrity of the point cloud data.

[0023] Secondly, non-destructive testing (NDT) equipment was used to test the material strength and reinforcement distribution of each component of the old building. For concrete components, a rebound hammer was used to test the surface hardness of the concrete, and an ultrasonic pulse velocity analyzer was used to measure the propagation speed of ultrasonic waves in the concrete to comprehensively estimate the strength grade of the concrete. For masonry structures, the penetration test or rebound test was used to test the strength grade of the masonry mortar. Reinforcement distribution was detected using a reinforcement scanner, which utilizes the principle of electromagnetic induction to detect the position, spacing, and protective layer thickness of the reinforcement inside the concrete component. The above NDT data was used to assign material property parameters to each component during subsequent modeling, so that the model not only contains geometric information but also material performance information reflecting the load-bearing capacity of the component.

[0024] Then, the system platform performs noise reduction processing on the collected 3D point cloud data, filtering out outliers and stray points caused by environmental interference; it registers and stitches multi-site point cloud data, using an iterative nearest-point algorithm to achieve precise alignment of cloud data from different sites; it then fuses the registered point cloud data with the appearance image data, using the color information of the image data to color the point cloud, enhancing the model's visualization and recognizability. After processing, the fused data is imported into BIM software for reverse fitting. By identifying geometric features such as planes, cylinders, and spheres in the point cloud data, the system fits the 3D geometric contours of structural components such as walls, beams, slabs, columns, staircases, and door and window openings. Simultaneously, based on the pipeline point cloud data, it fits the 3D orientation and connection relationships of pipeline networks such as water supply and drainage pipes, HVAC pipes, and cable trays, constructing an initial BIM model containing building geometric dimensions, structural component information, and pipeline network information.

[0025] Finally, the completed initial BIM model is compared and verified with the on-site measured data. The on-site measured data includes manual verification of key building dimensions using traditional surveying tools such as total stations, levels, and steel tape measures. The system compares the geometric dimensions, spatial positions, and other parameters of each component in the initial BIM model with the corresponding measured data one by one. When the deviation between the model parameters and the measured data of a component exceeds a preset threshold, the component is manually verified and the model is corrected to ensure that the geometric accuracy of the initial BIM model meets the requirements of subsequent renovation designs.

[0026] S102: Deploy sensors at multiple structural locations in the old building, collect structural response data in real time using the sensors, and establish a mapping relationship between the structural response data collected by each sensor and the corresponding component in the initial BIM model; Specifically, the sensor placement locations are first determined based on the structural characteristics of the old building and the construction plan in the renovation design. Sensors should be placed at key load-bearing areas such as load-bearing walls and beam-column joints to monitor the impact of renovation work on the stress state of these critical structural components; they should also be placed around slotted walls and open floor slabs within the planned renovation area to monitor the structural stress redistribution and deformation caused by localized renovation work; and they should be placed in areas with known cracks or settlement to monitor the development and changes of these defects during construction. The deployed sensors include strain sensors for monitoring structural stress changes, displacement sensors for monitoring structural deformation and settlement, crack gauges for monitoring dynamic changes in existing crack widths, vibration sensors for monitoring the impact of construction vibrations on the structure, temperature sensors for monitoring the impact of ambient temperature on structural material properties, and humidity sensors for monitoring the impact of ambient humidity on the durability of masonry and concrete. Depending on the monitoring purpose and object, different types and ranges of sensors can be selected for different parts of the same building.

[0027] Each sensor is equipped with a wireless communication module, forming a self-organizing sensor network. The sensors collect structural response data of their respective monitoring parameters in real time according to a preset sampling frequency. The collected data is transmitted to the edge computing gateway via the self-organizing sensor network using a multi-hop relay method. The edge computing gateway is deployed at the construction site and performs preliminary preprocessing on the received raw sensor data, including data verification to remove obviously abnormal, threshold-exceeding erroneous data, data filtering to eliminate signal fluctuations caused by environmental noise, and data compression to reduce the amount of data transmitted. The preprocessed structural response data, carrying the sensor number and timestamp, is uploaded to the system platform via a 5G communication module or an industrial Ethernet interface.

[0028] Then, the system platform assigns a unique identifier to each component in the initial BIM model. During installation, each sensor acquires its actual spatial coordinates on-site using a total station or positioning device; this spatial coordinate information, along with the sensor number, is entered into the system platform. After acquiring the spatial coordinate information of each sensor, the system platform matches and calculates these coordinates with the spatial coordinates of each component in the initial BIM model to determine the components to which each sensor is attached or adjacent, thus establishing a correspondence between sensors and components. Once the mapping and association are complete, the system platform automatically tags the structural response data uploaded in real-time by each sensor with the corresponding component's unique identifier and receiving timestamp. The tagged structural response data is then categorized and stored in the system platform's database by component, enabling the monitoring data from each sensor to be traced back to the corresponding component in the BIM model through the component's unique identifier.

[0029] S103: Obtain multi-phase structural response data at different time points, compare and analyze the multi-phase structural response data according to the time series, extract the changing trend of the structural response parameters of each component in the time dimension, and generate a health status time series map of each component based on the changing trend; Specifically, the system platform reads at least one monitoring parameter from the database, including strain data, displacement data, crack width data, and vibration data uploaded to the same component at different time points. This data comes from multi-period observation datasets continuously collected and stored by the sensor network during the renovation design phase, construction preparation phase, and the entire renovation construction process. The system platform arranges the monitoring parameters of the same component in chronological order of acquisition, generating time-series curves of each monitoring parameter's variation over time, with time as the horizontal axis and the monitoring parameter value as the vertical axis.

[0030] Based on the generated time-series curves, the system platform uses trend analysis algorithms to calculate the rate of change and cumulative change of each monitored parameter. For strain data, it calculates the strain increment and its rate of change between adjacent time nodes, reflecting the speed of evolution of the stress state of the component; for displacement data, it calculates the cumulative displacement and displacement rate, reflecting the continuous development trend of component deformation; for crack width data, it calculates the crack propagation rate, reflecting the degree of active development of existing damage; and for vibration data, it calculates the peak vibration and cumulative vibration energy, reflecting the degree of continuous impact of construction vibration on the component.

[0031] Based on the calculated rate of change and cumulative change, the system platform generates an independent health status time series map for each component, indexed by its unique identifier. This health status time series map records the trajectory of each monitored parameter throughout the entire process from the start of monitoring to the current moment. Specifically, it includes stress-strain state data at each time point, cumulative data of structural deformation offset, width and propagation rate data of existing cracks at different time points, and vibration response characteristics of the structure at different construction stages. The health status time series map is presented visually, allowing users to slide along the timeline within the system platform to view the component's status at any historical moment.

[0032] S104: Based on the health status time series map, establish a component evaluation system covering safety indicators, durability indicators and functional integrity indicators. According to the component evaluation system, evaluate and classify each component in the old building, and generate an old building renovation design scheme in combination with renovation needs and constraints. Specifically, the first step is to establish a component evaluation system that covers safety indicators, durability indicators, and functional integrity indicators.

[0033] The quantitative calculation method for safety indicators is as follows: The system platform reads the stress monitoring data of each component at the current time node from the health status time series map. Simultaneously, based on the material strength information in the non-destructive testing data, it calculates the stress level of the component under the current load conditions and the stress level under the expected construction load conditions. The remaining strength of the material is compared with the aforementioned stress levels to calculate the component's bearing capacity margin under the current load and the expected construction load. This bearing capacity margin is used as the quantitative value of the safety indicator. The larger the bearing capacity margin, the higher the safety reserve of the component.

[0034] The durability index is quantified as follows: The system platform reads crack propagation rate and material degradation rate data for each component from the health status time series map. The crack propagation rate is obtained by linear regression or exponential fitting of the crack width time series data, and the material degradation rate is determined based on the changing trends of concrete carbonation depth or steel corrosion potential. Based on the above rate data, combined with the current degree of damage to the component and the design service life requirements, the remaining service life of the component is estimated, and this remaining service life is used as the quantified value of the durability index.

[0035] The quantitative calculation method for the functional integrity index is as follows: The system platform reads the displacement and vibration data of each component from the health status time series map. Based on the displacement data, it determines whether the component has undergone deformation beyond the allowable range, thereby affecting the normal collaborative work of adjacent components. Based on the vibration data, it determines whether the component has suffered new damage due to construction vibration, thereby affecting the overall use function of the building. The above information is combined to calculate the degree of impact of the component on the normal use function of the building, and the degree of impact is used as the quantitative value of the functional integrity index.

[0036] After quantifying the three indicators separately, the system platform weights and combines the quantified values ​​of the safety, durability, and functional integrity indicators according to preset weighting coefficients to obtain a comprehensive evaluation score for each component. The weighting coefficients can be adjusted according to the actual situation of different buildings. For example, the weight of the safety indicator can be increased for buildings with insufficient structural safety margins, and the weight of the durability indicator can be increased for buildings with long-term use requirements.

[0037] Then, the system platform assesses and classifies each component in the old building based on its comprehensive evaluation score. The system platform has a first preset threshold and a second preset threshold, with the first threshold being higher than the second. When a component's comprehensive evaluation score is higher than the first preset threshold, it indicates that the component is in good condition and meets the conditions for continued safe use; the component is marked as a retainable component and will be preserved in subsequent renovations. When a component's comprehensive evaluation score is between the first and second preset thresholds, it indicates that the component has a certain degree of performance degradation or damage, but its load-bearing capacity or usability can still be restored through reinforcement measures; the component is marked as a reinforced and renovated component, and a corresponding reinforcement scheme is matched from a preset reinforcement measure library based on the specific damage type of the component. The preset reinforcement measure library stores various common component damage types and their corresponding reinforcement techniques, such as carbon fiber reinforcement for insufficient flexural bearing capacity of concrete beams, reinforced concrete mesh cement mortar surface reinforcement for insufficient seismic resistance of masonry walls, and pressure grouting sealing for excessive crack width. The system platform automatically matches the most suitable reinforcement measure based on the component's damage characteristic data.

[0038] When the comprehensive evaluation score of a component is lower than the second preset threshold, it indicates that the component has been severely degraded or damaged, and its load-bearing capacity or function can no longer be effectively restored by conventional reinforcement methods. The component is marked as a replacement component and will be removed and replaced in subsequent renovations.

[0039] After the assessment and classification are completed, the system platform accepts the renovation requirements and constraints input by the designers. Renovation requirements include functional change requests from the owner or designer, such as proposed changes to the spatial location, proposed new functional configurations, and proposed upgrades to equipment types. Constraints include budget limitations, construction period requirements, and the preservation of historical architectural elements. Based on the marking results of each component and the aforementioned renovation requirements and constraints, the system platform determines the scope and measures of the renovation, automatically generating a preliminary renovation design scheme that includes structural reinforcement plans and construction sequences. During the generation process, the system platform prioritizes utilizing the existing structural load-bearing capacity of components marked for preservation and reuse, matching corresponding reinforcement schemes to areas marked for reinforcement and incorporating them into the construction plan, and planning demolition and new construction schemes for areas marked for replacement components. After the preliminary renovation design scheme is generated, the system platform presents it in a 3D visualization within the initial BIM model, showcasing the renovation scope, reinforcement locations, and construction sequence through highlighting, coloring, or dynamic simulation, allowing designers to review and manually adjust it.

[0040] S105: During the renovation of old buildings, real-time structural response data from various sensors are continuously collected. The real-time structural response data is compared with the health status time series map. When the real-time structural response data deviates from the expected trend in the health status time series map, the component evaluation and classification and renovation scheme generation are re-executed based on the current real-time structural response data to update the renovation design scheme. The updated renovation design scheme is then fed back to the construction end.

[0041] Specifically, throughout the entire renovation process of the old building, the sensor network operates continuously, collecting structural response data from each sensor in real time at the same sampling frequency as during the renovation design phase and uploading it to the system platform. The system platform continuously receives real-time structural response data.

[0042] The system platform extracts the expected range of structural response parameters for each component at the current time point from the generated health status time series map. This expected range is based on the historical variation trajectory of each monitored parameter of the component under normal conditions recorded in the health status time series map, and is extrapolated through time series prediction to obtain the normal fluctuation range at the current moment. The system platform dynamically compares the real-time collected structural response data with the above expected range.

[0043] When the real-time acquired structural response data exceeds the expected value range but the duration is short, the system platform will not trigger the correction process to rule out misjudgments caused by accidental signal jitter or instantaneous impact. When the duration of the real-time acquired structural response data exceeding the expected value range exceeds a preset time threshold, the system platform determines that the real-time structural response data has indeed deviated from the expected trend, indicating a substantial deviation between the actual state of the component and the design expectation, which may be caused by unforeseen factors or construction deviations during the construction process.

[0044] At this point, the system platform immediately issues an early warning signal, notifying on-site construction management personnel and designers to pay attention to the anomaly. Simultaneously, the system platform automatically triggers a design correction process: using the real-time structural response data collected at the current moment as the latest component status input, this real-time data replaces the corresponding historical data at earlier time nodes in the health status time series diagram. Based on the updated dataset, the health status time series diagram for each component is recalculated. Then, based on the updated health status time series diagram, the component evaluation classification and modification scheme generation are re-executed according to the same component evaluation system and evaluation classification method as in step S104, resulting in an updated modification design scheme.

[0045] The system platform compares the updated renovation design with the currently implemented design item by item, identifying specific differences in reinforcement scope, reinforcement measures, and construction sequence. Based on these differences, it automatically generates a design change order. This order details the specific construction content to be adjusted, the reasons for the adjustment, and the revised construction requirements. The system platform pushes the design change order to the construction end via a wireless communication network. The construction end can be a mobile terminal device of on-site construction personnel or an electronic display screen deployed on the construction site. Simultaneously, the system platform synchronizes the updated renovation design to the model building module 202, modifying and updating the initial BIM model accordingly to ensure that the BIM model remains consistent with the latest design version. This process is executed cyclically throughout the entire construction cycle, achieving a closed-loop iteration of monitoring, evaluation, correction, and re-monitoring.

[0046] Second embodiment: Please refer to Figure 2 This invention provides a BIM-based and real-time monitoring-based old building renovation design system, including a data acquisition module 201, a model building module 202, a sensor network module 203, a data fusion module 204, an evaluation and design module 205, and a dynamic correction module 206.

[0047] The data acquisition module 201 is connected to the model building module 202. The data acquisition module 201 is used to acquire 3D point cloud data and non-destructive testing data of the old building and send the acquired data to the model building module 202. The specific working process of the data acquisition module 201 is as follows: it uses a 3D laser scanner to acquire 3D point cloud data of the interior and exterior of the old building; it uses UAV aerial photography and close-range photogrammetry to acquire exterior image data; and it uses non-destructive testing equipment such as rebound hammers, ultrasonic detectors, and rebar scanners to acquire material strength data and rebar distribution data of each component.

[0048] The model building module 202 is connected to the data fusion module 204. The model building module 202 receives 3D point cloud data and non-destructive testing data sent by the data acquisition module 201. After denoising, registration, and fusion processing of these data, it performs inverse fitting in the BIM software to construct an initial BIM model containing building geometry, structural component information, and pipeline network information. The completed initial BIM model is then sent to the data fusion module 204. The model building module 202 also compares and verifies the initial BIM model with the on-site measured data, corrects components with deviations exceeding a preset threshold, and assigns a unique identifier to each component.

[0049] Sensor network module 203 is connected to data fusion module 204. Sensor network module 203 includes multiple sensors deployed in various structural locations of the old building. These sensors are located in load-bearing walls, beam-column joints, grooved walls within the proposed renovation area, open floor slabs within the proposed renovation area, and areas known to have cracks or settlement defects. The sensors include various types such as strain sensors, displacement sensors, crack gauges, vibration sensors, temperature sensors, and humidity sensors. Each sensor forms a self-organizing sensor network via a wireless communication module. After real-time acquisition and preprocessing of the structural response data collected by the sensors through an edge computing gateway, the data is uploaded to data fusion module 204 via 5G communication or industrial Ethernet.

[0050] The data fusion module 204 is connected to the evaluation and design module 205. The data fusion module 204 receives structural response data from each sensor uploaded by the sensor network module 203, and the initial BIM model sent by the model building module 202. The data fusion module 204 acquires the spatial coordinate information of each sensor, matches this spatial coordinate information with the spatial coordinates of each component in the initial BIM model, establishes the correspondence between sensors and components, and marks the structural response data collected by each sensor with a unique component identifier and timestamp. The data fusion module 204 also organizes the structural response data from each sensor according to a time series, generating a health status time series map for each component containing multiple periods of monitoring data, and sends the health status time series map to the evaluation and design module 205.

[0051] The evaluation and design module 205 is connected to the dynamic correction module 206. The evaluation and design module 205 receives the health status time series map sent by the data fusion module 204, establishes a component evaluation system covering safety indicators, durability indicators, and functional integrity indicators based on the health status time series map, evaluates and classifies each component in the old building according to the component evaluation system, and generates a renovation design scheme in combination with renovation needs and constraints. Then, the renovation design scheme is sent to the dynamic correction module 206.

[0052] The dynamic correction module 206 is connected to the evaluation and design module 205, the sensor network module 203, and the model building module 202. During the renovation of old buildings, the dynamic correction module 206 receives real-time structural response data uploaded by the sensor network module 203, compares this data with the expected trend in the health status time series graph, and triggers the evaluation and design module 205 to regenerate an updated renovation design scheme based on the current data when the real-time structural response data deviates from the expected trend. The updated design scheme is then fed back to the construction end and the model building module 202 to update the initial BIM model. The dynamic correction module 206 also issues warning signals when the correction process is triggered and generates design change instructions by comparing the updated design scheme with the currently implemented scheme and pushing them to the construction end. Thus, the system fully realizes a closed-loop process for the renovation design of old buildings, from data acquisition, model building, sensor monitoring, data fusion, evaluation and design to dynamic correction.

[0053] This invention establishes an initial BIM model and a health status time series diagram during the renovation design phase, and continuously collects real-time structural response data during construction for dynamic comparison and automatic correction. This enables the dynamic evolution of the BIM model with the construction process and the closed-loop iteration of the design scheme based on the actual structural response. It solves the problems of static BIM models, disconnect between monitoring data and BIM models, and inability to dynamically adjust design schemes in existing technologies, effectively improving the accuracy, safety, and adaptability of old building renovation design.

[0054] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A design method for the renovation of old buildings based on BIM and real-time monitoring, characterized in that, Includes the following steps: Collect 3D point cloud data and non-destructive testing data of the old building, and build an initial BIM model of the old building based on the collected data; Sensors are deployed at multiple structural locations in the old building to collect structural response data in real time. The structural response data collected by each sensor is then mapped and associated with the corresponding component in the initial BIM model. Obtain multi-phase structural response data at different time points, compare and analyze the multi-phase structural response data according to the time series, extract the changing trend of structural response parameters of each component in the time dimension, and generate a health status time series map of each component based on the changing trend; Based on the aforementioned health status time series map, a component evaluation system covering safety indicators, durability indicators, and functional integrity indicators is established. Each component in the old building is evaluated and classified according to the component evaluation system, and a renovation design scheme for the old building is generated by combining the renovation needs and constraints. During the renovation of old buildings, real-time structural response data from various sensors are continuously collected. The real-time structural response data is compared with the health status time series map. When the real-time structural response data deviates from the expected trend in the health status time series map, the component evaluation and classification and renovation scheme generation are re-executed based on the current real-time structural response data to update the renovation design scheme. The updated renovation design scheme is then fed back to the construction end.

2. The old building renovation design method based on BIM and real-time monitoring as described in claim 1, characterized in that, Collect 3D point cloud data and non-destructive testing data of the old building, and build an initial BIM model of the old building based on the collected data, specifically including: A 3D laser scanner was used to perform a full-area scan of the old building to obtain 3D point cloud data of the interior and exterior of the old building. At least one of the following methods was used to collect the exterior image data of the old building: drone aerial photography and close-range photogrammetry. Non-destructive testing equipment was used to obtain material strength data and steel reinforcement distribution data for each component of the old building. The collected 3D point cloud data, appearance image data, material strength data and steel reinforcement distribution data are denoised, registered and fused. Inverse fitting is performed in BIM software to construct an initial BIM model containing building geometry, structural component information and pipeline network information. The initial BIM model is compared and verified with the on-site measured data, and components with deviations exceeding a preset threshold are corrected.

3. The old building renovation design method based on BIM and real-time monitoring as described in claim 1, characterized in that, Sensors were deployed at multiple structural locations within the old building, specifically including: Sensors were deployed in load-bearing walls, beam-column joints, slotted walls in the proposed renovation area, open floor slabs in the proposed renovation area, and areas with known cracks or settlement defects. The deployed sensors include a variety of strain sensors, displacement sensors, crack gauges, vibration sensors, temperature sensors, and humidity sensors. Each sensor forms a self-organizing sensor network through a wireless communication module. After the structural response data collected by the sensors is acquired and preprocessed in real time through an edge computing gateway, it is uploaded to the system platform via 5G communication or industrial Ethernet.

4. The old building renovation design method based on BIM and real-time monitoring as described in claim 1, characterized in that, Establish a mapping association between the structural response data collected by each sensor and the corresponding component in the initial BIM model, specifically including: Acquire the spatial coordinate information of each sensor, match the spatial coordinate information with the spatial coordinates of each component in the initial BIM model, and establish the correspondence between the sensor and the component; Each component in the initial BIM model is assigned a unique identifier, and the structural response data collected by each sensor is labeled with the corresponding component unique identifier and timestamp and then stored in the system platform.

5. The old building renovation design method based on BIM and real-time monitoring as described in claim 1, characterized in that, Extract the time-dimensional variation trend of the structural response parameters of each component, specifically including: Acquire at least one of the strain data, displacement data, crack width data, and vibration data of the same component at different time points, arrange the acquired data in chronological order, and generate time series curves for each monitoring parameter; Based on the time series curve, a trend analysis algorithm is used to calculate the rate of change and cumulative change of each monitoring parameter; Based on the rate of change and the cumulative amount of change, a health state time series map is generated for each component. The health state time series map includes the stress-strain state, deformation offset, crack propagation rate and vibration response characteristics of each component at each time point.

6. The old building renovation design method based on BIM and real-time monitoring as described in claim 1, characterized in that, Establish a component evaluation system covering safety indicators, durability indicators, and functional integrity indicators, specifically including: Based on the stress monitoring data and remaining material strength of each component in its current state, the bearing capacity margin of the component under the current load and the expected construction load is calculated, and the bearing capacity margin is used as the quantitative value of the safety index. Based on the crack propagation rate and material degradation rate of each component, the remaining service life of the component is calculated, and the remaining service life is used as a quantitative value of the durability index. Based on the displacement and vibration data of each component, the degree of impact of the component on the normal use function of the building is calculated, and the degree of impact is used as the quantitative value of the functional integrity index. The quantitative values ​​of the safety index, durability index, and functional integrity index are weighted and combined to obtain the comprehensive evaluation score for each component.

7. The old building renovation design method based on BIM and real-time monitoring as described in claim 1, characterized in that, Based on the aforementioned component evaluation system, each component in the old building is evaluated and classified. Combined with renovation needs and constraints, a renovation design scheme for the old building is generated, specifically including: When the overall evaluation score of a component is higher than the first preset threshold, the component will be marked as a component to be retained and utilized. When the comprehensive evaluation score of a component is between the first preset threshold and the second preset threshold, the component is marked as a component to be reinforced and modified, and a corresponding reinforcement scheme is matched from the preset reinforcement measure library based on the specific damage type of the component. When the overall evaluation score of a component is lower than the second preset threshold, the component will be marked as a replacement component. Based on the marking results of each component and the proposed changes to the spatial area and functional configuration in the renovation requirements, the scope of renovation and renovation measures are determined, and a preliminary renovation design scheme including structural reinforcement scheme and construction sequence is generated. The preliminary renovation design scheme is presented in three-dimensional visualization in the initial BIM model.

8. The old building renovation design method based on BIM and real-time monitoring as described in claim 1, characterized in that, The real-time structural response data is compared with the health status time series map, specifically including: Extract the expected range of structural response parameters of each component at the current time node from the health status time series graph, and compare the real-time collected structural response data with the expected range. When the duration of the real-time collected structural response data exceeding the expected value range exceeds a preset time threshold, it is determined that the real-time structural response data deviates from the expected trend.

9. The old building renovation design method based on BIM and real-time monitoring as described in claim 8, characterized in that, When real-time structural response data deviates from the expected trend, specifically including: The system platform issues an early warning signal and replaces the historical data of previous time nodes with the real-time structural response data collected at the current moment, and recalculates the health status time sequence map of each component; Based on the updated health status time series map, the component evaluation classification and modification scheme generation are re-executed to obtain the updated modification design scheme; The updated renovation design scheme is compared with the currently implemented renovation design scheme to generate a design change instruction; The design change instruction is pushed to the construction end, and the initial BIM model is updated simultaneously.

10. A BIM-based and real-time monitoring-based old building renovation design system, used to implement the BIM-based and real-time monitoring-based old building renovation design method as described in claim 1, characterized in that, It includes a data acquisition module, a model building module, a sensor network module, a data fusion module, an evaluation design module, and a dynamic correction module; the data acquisition module is connected to the model building module, the model building module is connected to the data fusion module, the sensor network module is connected to the data fusion module, the data fusion module is connected to the evaluation design module, the evaluation design module is connected to the dynamic correction module, and the dynamic correction module is connected to the evaluation design, the sensor network module, and the model building module; The data acquisition module is used to collect three-dimensional point cloud data and non-destructive testing data of the old building, and send the collected data to the model building module; The model building module is used to build an initial BIM model of the old building based on the three-dimensional point cloud data and non-destructive testing data, and send the initial BIM model to the data fusion module. The sensor network module includes multiple sensors deployed at multiple structural locations of the old building. The sensors are used to collect structural response data in real time and upload the structural response data to the data fusion module via a wireless communication network. The data fusion module is used to establish a mapping relationship between the structural response data collected by each sensor and the corresponding component in the initial BIM model, and to organize the structural response data of each sensor according to the time series to generate a health status time series map of each component containing multiple monitoring data, and send the health status time series map to the evaluation and design module. The assessment and design module is used to establish a component assessment system covering safety indicators, durability indicators and functional integrity indicators based on the health status time series map. According to the component assessment system, each component in the old building is assessed and classified, and a renovation design scheme is generated in combination with renovation needs and constraints. The renovation design scheme is then sent to the dynamic correction module. The dynamic correction module is used to receive real-time structural response data uploaded by the sensor network module during the renovation of old buildings, compare the real-time structural response data with the expected change trend in the health status time series map, and trigger the evaluation design module to regenerate an updated renovation design scheme based on the current real-time structural response data when the real-time structural response data deviates from the expected change trend. The updated renovation design scheme is then fed back to the construction end and the model building module to update the initial BIM model.

Images