A building cantilever frame system installation optimization method based on BIM

Abstract

This invention relates to the field of building construction technology, and in particular to a BIM-based optimization method for the installation of a cantilever scaffolding system. The method includes: constructing a three-dimensional building information model based on a BIM model and building structure data containing walls with reverse curved slopes; determining the cantilever scaffolding installation area and three-dimensional coordinates; determining the initial theoretical stress value and initial installation depth of anchor points based on preset loads; obtaining the actual coordinates after installation, determining the number of deviation points, and determining the cantilever scaffolding deflection change and secondary theoretical stress value based on coordinate deviation parameters; and determining the target installation depth or installation method based on the actual influence deviation value, the influence deviation threshold, and building structure data. This invention achieves precise, safe, and efficient cantilever scaffolding installation by adjusting the installation depth and method according to the special geometric characteristics and stress state of complex building structures containing walls with reverse curved slopes.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a BIM-based method for optimizing the installation of a building cantilever scaffolding system. Background Technology

[0002] Cantilevered scaffolding is a subtype of scaffolding, specifically referring to scaffolding erected from the main building structure outwards through cantilevered load-bearing structures, mainly used in the construction of high-rise buildings or complex structures. Existing cantilevered scaffolding installation methods largely rely on pre-set construction plans, determining installation points based on static mechanical calculations. However, in actual construction, due to factors such as measurement errors, structural deformation, and material tolerances, deviations in installation points are prone to occur. Traditional methods lag behind post-construction assessments of the impact of these deviations and struggle to quantify the transmission effect of a single point deviation on the overall scaffolding structure, potentially leading to safety hazards or increased rework costs. While BIM technology has been applied to cantilevered scaffolding modeling, current technology lacks real-time linkage between the BIM model, mechanical simulation, and on-site deviation data. This prevents dynamic correction of the installation plan or verification of the simulation model's accuracy, thus limiting the precision and safety of cantilevered scaffolding installation.

[0003] Chinese Patent Publication No. CN112069586A discloses a design and construction method for installing steel cantilever scaffolding on a cantilever structure, including: 1. drawing a plan layout of the steel cantilever scaffolding; 2. optimizing the position of the cantilever steel beams; 3. determining the calculation unit of the concrete cantilever structure; 4. calculating the bearing capacity of the steel cantilever scaffolding; 5. statistically calculating the reaction force of the cantilever scaffolding supports; 6. modeling and verifying the concrete cantilever structure; and 7. erecting the steel cantilever scaffolding. This invention uses the side beams of the concrete cantilever structure as supports for the cantilever steel beams of the scaffolding, solving the nationwide technical problem of not being able to erect cantilever scaffolding on large cantilever concrete structures. Compared with traditional technologies, it significantly shortens the construction period, greatly saves on overall construction costs, and the construction method is simple, highly operable, and has widespread application value. It has significant economic and social benefits and meets the requirements of high-efficiency, energy-saving, and green construction.

[0004] It is evident that existing technologies have the following problems: In complex building structures with walls containing reverse curved slopes, the installation of cantilever frames is prone to problems such as poor adaptability of the installation area, excessive stress at anchor points, and structural safety issues due to the special geometric characteristics of the walls, the difficulty in controlling construction precision, and the complex stress state. Therefore, it is impossible to achieve precise, safe, and efficient installation of cantilever frames. Summary of the Invention

[0005] To address this, the present invention provides a BIM-based optimization method for the installation of a building cantilever system. This method overcomes the problems in existing technologies for complex building structures with walls containing reverse curved slopes. Due to the special geometric features of the walls, the difficulty in controlling construction precision, and the complex stress state, traditional installation methods often suffer from poor adaptability to the installation area, excessive stress at anchor points, and structural safety issues caused by actual installation deviations. Consequently, the methods fail to achieve precise, safe, and efficient cantilever installation.

[0006] To achieve the above objectives, this invention provides a BIM-based method for optimizing the installation of a building cantilever scaffolding system, comprising: A three-dimensional building information model of the target building is constructed based on the BIM model and the main structural data of the building containing the reverse curved slope wall. The cantilever installation area is determined based on the three-dimensional building information model, and the three-dimensional coordinates of the initial preset installation points of the cantilever are marked. A mechanical simulation model is constructed based on the three-dimensional coordinates and mechanical simulation software. The initial theoretical force value of the anchorage installation point is determined based on the mechanical simulation model and the preset load of the cantilever frame installation area. The initial installation depth of the anchorage installation point is determined based on the initial theoretical force value. Based on the three-dimensional coordinates, the preset installation points are actually installed to obtain the actual installation point coordinates. The three-dimensional coordinates and the actual installation point coordinates are compared to determine the number of deviation points. Based on the number of deviation points and the coordinate deviation point parameters, the deflection change of the cantilever frame is determined. Based on the deflection change of the cantilever frame, the secondary theoretical force value of the coordinate point is determined. The actual influence deviation value is determined based on the initial theoretical force value and the secondary theoretical force value. The target installation depth or installation method is determined based on the actual impact deviation value and the impact deviation threshold, as well as the building main structure data. The coordinate deviation point parameters include the coordinate deviation point value and the position of the deviation point; the secondary theoretical force value is positively correlated with the deflection change of the cantilever frame.

[0007] Furthermore, the process of constructing a three-dimensional building information model of the target building based on the BIM model and the building structure data of the reverse curved slope wall includes, Obtain the overall dimensions of the main building and the special area parameters of the reverse curved slope wall. Based on the overall dimensions and the special area parameters, determine the main building structure data. Input the main building structure data into the BIM model to obtain a three-dimensional building information model. The overall size data includes the global coordinates of the main building and the frame dimensions of the main building, while the special area parameters include the curvature of the exterior walls and the slope of the exterior walls.

[0008] Furthermore, the process of determining the cantilever installation area based on the aforementioned three-dimensional building information model includes, The installation area of ​​the cantilever frame is determined based on the bottom elevation, top elevation, and horizontal projection range of the wall with reverse curved slope. The horizontal projection range is the horizontal projection area of ​​the reverse curved slope wall on the ground.

[0009] Furthermore, the process of marking the three-dimensional coordinates of the initial preset installation points of the cantilever frame includes, The three-dimensional coordinates of the initial preset installation point are determined and marked based on the projection point of the bottom elevation on the reverse curved slope wall and the horizontal projection area.

[0010] Furthermore, the process of determining the initial theoretical force value of the anchorage installation point based on the mechanical simulation model and the preset load of the cantilever frame installation area includes, Input the preset load into the mechanical simulation model to obtain the initial theoretical force value at the anchorage installation point; The preset load includes the structural load of the cantilever frame itself, the construction load, and the additional load.

[0011] Furthermore, the process of determining the initial installation depth of the anchorage installation point based on the initial theoretical force value includes, The initial installation depth is determined based on the initial force value and the installation depth coefficient. The installation depth coefficient is a compensation parameter for the influence of the initial stress value on the initial installation depth. The initial stress value is positively correlated with the initial installation depth. The installation depth coefficient is determined based on the concrete strength grade and the thickness of the reverse curved slope wall in the main structure data.

[0012] Furthermore, the process of comparing the three-dimensional coordinates with the actual installation point coordinates to determine the number of deviation points includes, Planar deviation and elevation deviation are obtained based on three-dimensional coordinates and actual installation point coordinates, and the comprehensive deviation is determined based on the plane deviation and elevation deviation. Based on the plane deviation and the plane deviation threshold, the plane deviation comparison results and the plane coordinate deviation point parameters are obtained; The elevation deviation comparison results and elevation coordinate deviation point parameters are obtained based on the elevation deviation and elevation deviation threshold. Based on the comprehensive deviation and the comprehensive deviation threshold, the comprehensive deviation comparison results and the comprehensive coordinate deviation point parameters are obtained; If the plane deviation is greater than the plane deviation threshold, or the elevation deviation is greater than the elevation deviation threshold, or the combined deviation is greater than the combined deviation threshold, then the point is a deviation point. The number of deviation points is counted and obtained.

[0013] Furthermore, the process of determining the deflection change of the cantilever frame based on the number of deviation points and the coordinate deviation point parameters includes: The weighting parameter of the coordinate deviation point on the change in cantilever deflection is determined based on its location, and the change in cantilever deflection is determined based on the weighting parameter and the number of deviation points.

[0014] Furthermore, the process of determining the actual influence deviation value based on the initial theoretical force value and the secondary theoretical force value includes, Based on the comparison results of the initial theoretical force value and the secondary theoretical force value, the actual influence deviation value is determined. If the initial theoretical force value is greater than or equal to the secondary theoretical force value, then the actual influence deviation value is the initial influence deviation value. Since the initial theoretical force value is less than the secondary theoretical force value, the actual influence deviation value is determined based on the difference between the secondary theoretical force value and the initial theoretical force value. The initial theoretical stress value is determined based on the maximum stress value at the anchorage installation point; the initial influence deviation value is a preset stress fluctuation benchmark value, determined according to the first-level safety level of the main building structure.

[0015] Furthermore, the process of determining the target installation depth, or installation method, based on the actual impact deviation value and the impact deviation threshold, as well as the building's main structural data, includes: Based on the fact that the actual impact deviation value is less than or equal to the first-level deviation threshold, the current installation depth and installation method shall be maintained. Based on the actual impact deviation value being greater than the first-level deviation threshold and less than the second-level deviation threshold, the maximum allowable installation depth at the current location is determined based on the building's main structural data. The target installation depth is determined based on the difference between the initial installation depth, the second-level deviation threshold, and the actual impact deviation value. The installation method is determined based on the comparison between the target installation depth and the maximum allowable installation depth. If the actual impact deviation value is greater than or equal to the third-level deviation threshold, the installation method is determined based on the difference between the actual impact deviation value and the third-level deviation threshold. The installation methods include chemical anchor bolt anchoring, pre-embedded component welding, and combined anchoring.

[0016] Compared with existing technologies, the advantages of this invention lie in its ability to fully adapt to complex building structures with reverse curved slopes through BIM model construction and precise determination of the installation area. This ensures a high degree of matching between the cantilever frame installation area and the wall space characteristics, avoiding installation conflicts caused by structural specialties and improving the accuracy and rationality of installation area planning. By combining mechanical simulation software to calculate the initial theoretical stress value and initial installation depth, a scientific prediction of the stress state at anchorage points is achieved, making the initial installation depth setting more closely match actual stress requirements and laying a theoretical foundation for the safety and stability of the cantilever frame system. Through comparative analysis of actual installation points and preset points, the impact of deviations on cantilever frame deflection and secondary stress is quantified, forming a closed-loop control from design to construction. This effectively identifies and assesses the risks brought about by installation deviations and improves the control over construction accuracy. By comparing the actual impact deviation value with the threshold and dynamically adjusting the target installation depth or installation method in conjunction with the building's main structural data, the problem of deviation exceeding the limit can be addressed in a targeted manner. While ensuring structural safety, the economy and feasibility of the installation scheme are optimized, ensuring that the cantilever frame system can be installed safely, efficiently, and accurately in complex wall structures.

[0017] Furthermore, by integrating the overall dimensional data of the main building structure with the special regional parameters of the reverse-curved slope walls, the integrity and relevance of the main building structure data were ensured, providing a precise basis for 3D modeling. In BIM modeling, the basic form and attributes of the building frame were accurately reproduced, while detailed modeling was performed for the special structures of the reverse-curved slope walls, such as their arcuate features and inclined slopes. By embedding coordinates into details such as reserved openings, a precise digital representation of complex wall structures was achieved. The post-modeling verification process further ensured the consistency between the model and design parameters, enabling the generated 3D building information model to intuitively and accurately reflect the spatial relationships, structural characteristics, and material properties of various building components. This provided a reliable digital foundation for subsequent work such as determining the cantilever frame installation area and marking points, effectively improving the accuracy and efficiency of subsequent construction planning.

[0018] Furthermore, by combining the elevation and horizontal projection range of the reverse curved slope wall, the installation area was determined. This ensured that the area covered the entire construction area of ​​the wall, and through reasonable vertical and horizontal expansion, met the construction operation space requirements, allowing the cantilever scaffold to adapt to the curvature and tilt characteristics of the wall. Utilizing the collision detection function of the BIM model, obstacles such as window openings and cantilever beams were accurately identified and avoided, and the boundaries of the installation area were dynamically adjusted, effectively preventing conflicts between the scaffold and building components, and improving the feasibility and safety of the installation area. The final determined installation area, through 3D marking and data export, provided a clear and accurate spatial range basis for the subsequent initial pre-set installation point marking, ensuring a high degree of adaptation between the point planning and the wall structure and construction requirements, laying the foundation for the precise installation of the cantilever scaffold.

[0019] Furthermore, using the bottom elevation projection point as a benchmark, and combining the horizontal projection area to expand the vertical points, the initial preset installation point distribution can adapt to the arc and tilt characteristics of the reverse curved slope wall, and also match the building frame structure such as the spacing of frame columns, ensuring the rationality of the point layout. During annotation, information such as the local characteristics of the wall and the distance to window openings is simultaneously linked, providing an intuitive reference for subsequent stress verification and helping to accurately assess the stress state of the points. The BIM model verifies the point spacing, distance from obstacles, and coordinate range, ensuring that all points meet construction specifications and safety requirements, avoiding installation conflicts or uneven stress caused by improper point placement, providing a reliable coordinate basis for the safe and accurate installation of the cantilever frame, and improving the scientific nature and efficiency of construction planning.

[0020] Furthermore, by importing the core data of the BIM model into mechanical simulation software, the geometric features, material properties, and anchorage connection methods of the reverse curved slope wall are accurately reproduced, providing a realistic model basis for stress analysis. Considering the high complexity of curved wall construction, preset loads, including the self-weight of the frame, construction loads, and additional loads, are rationally determined, fully taking into account special factors such as surface adaptation and operational difficulty, making the load values ​​more consistent with actual construction scenarios. Simulation calculations yield the initial theoretical stress values ​​for each anchorage point, clearly showing the stress differences at different locations, such as the root and top, and points with different connection methods. This provides a scientific basis for determining the initial installation depth, ensuring that the anchorage design can effectively cope with complex stress states and improving the safety and reliability of the cantilever frame system.

[0021] Furthermore, by combining the initial theoretical stress value with the installation depth coefficient to determine the initial installation depth, a precise match between stress requirements and installation depth is achieved. The positive correlation between the initial stress value and installation depth ensures sufficient depth support at points under high stress, enhancing anchoring safety. The installation depth coefficient is dynamically adjusted based on the concrete strength grade and wall thickness, fully considering the impact of material properties and structure on anchoring effectiveness, making the coefficient value more closely reflect actual working conditions. Correction coefficients for different stress types, such as tension-dominant or shear-dominant forces, further improve the targeting and accuracy of installation depth calculations. By verifying the compatibility of installation depth with wall thickness and protective layer requirements, and by adjusting the depth at special points, it is ensured that the initial installation depth meets both stress requirements and construction specifications, providing crucial assurance for the stability and reliability of anchoring points and offering a scientific quantitative basis for subsequent actual installation.

[0022] Furthermore, by calculating planar deviation, elevation deviation, and comprehensive deviation separately, the deviation of actual installation points in three-dimensional space was comprehensively considered, avoiding the limitations of single-dimensional evaluation and making the deviation analysis more comprehensive and accurate. By setting deviation thresholds based on the structural characteristics of the reverse-curved slope wall, such as curvature and slope, the threshold standards were ensured to be compatible with the special structure of the wall, improving the rationality and specificity of deviation judgment. By statistically analyzing the number of deviation points, the overall installation accuracy can be intuitively grasped, laying a data foundation for subsequent deflection change calculations and installation scheme optimization, and contributing to refined control of the construction process.

[0023] Furthermore, by assigning different weight parameters to the locations of deviation points, the difference in the impact of root and end points on the cantilever deflection is fully considered, conforming to the principle of the fulcrum effect in structural mechanics and making the weight allocation more consistent with the actual stress logic. Calculating the weight parameters in conjunction with the degree of deviation demonstrates the positive correlation between the magnitude of the deviation and the impact on deflection. In particular, the superposition calculation for points with multiple deviations exceeding the limit enhances the accuracy of the deflection analysis. Combining the weight parameters with the number of deviation points to calculate the total deflection change comprehensively considers the distribution range and degree of influence of the deviations, scientifically quantifying the effect of installation deviations on the cantilever deformation. By comparing with the allowable values ​​in the specifications, it is possible to clearly determine whether the deflection exceeds the limit, providing a direct basis for subsequent adjustments to the installation plan. This helps to promptly avoid structural safety risks caused by excessive deflection and ensures the stability of the cantilever system.

[0024] Furthermore, by using the maximum stress value at the anchorage point as the initial theoretical stress value benchmark, the core indicators for controlling installation safety were precisely identified, ensuring the targeted nature of the stress analysis. By establishing a positive correlation between the secondary theoretical stress value and the change in deflection, the additional stress caused by installation deviations was quantified, clearly demonstrating the impact of deviations on structural stress. The actual impact deviation value was dynamically determined based on the comparison between the initial stress value and the secondary theoretical stress value. When the stress value increased, the percentage difference was used to objectively reflect the stress increase caused by the deviation, avoiding the limitations of fixed deviation values ​​that are difficult to adapt to actual working conditions. The initial impact deviation value was set in conjunction with the building's main safety level, providing a reasonable benchmark for deviation assessment. The final actual impact deviation value can intuitively determine whether the stress exceeds the limit, providing a clear quantitative basis for subsequent adjustments to the installation depth or method, and helping to ensure the stress safety of the cantilever system under complex working conditions.

[0025] Furthermore, by adopting a tiered processing strategy for the actual impact deviation values ​​in different ranges, the installation scheme was refined. When the deviation value is between the first and second level thresholds, the target installation depth is calculated and compared with the maximum allowable depth. The depth is adjusted only without changing the installation method, compensating for the stress deviation while fully utilizing the load-bearing potential of the wall structure, thus balancing safety and economy. When the deviation value reaches the third level threshold, a combined anchoring method is adopted. The synergistic effect of the steel plate and anchor bolts enhances the overall stiffness and load-bearing capacity, adapting to the complex stress requirements of the reverse curved slope wall. Simultaneously, the installation scheme is verified using data from the main building structure to ensure that the adjusted depth and method meet the limitations of wall thickness and concrete strength, avoiding structural damage. The curved steel plate, customized for the reverse curved surface characteristics, ensures a good fit with the wall, reduces stress concentration, and makes the anchoring system more adaptable to the mechanical characteristics of the curved structure. This tiered adjustment mechanism comprehensively covers the processing needs of different deviation levels, effectively balancing safety, economy, and adaptability, and improving the reliability and stability of the cantilever system in complex wall structures. Attached Figure Description

[0026] Figure 1 This is a flowchart of the BIM-based building cantilever system installation optimization method in this embodiment; Figure 2 This is a flowchart illustrating the process of determining the number of deviation points in the BIM-based building cantilever system installation optimization method of this embodiment. Figure 3 This is a flowchart illustrating the process of determining the actual impact deviation value in the BIM-based building cantilever system installation optimization method of this embodiment. Figure 4 This is a flowchart illustrating the process of determining the target installation depth, or installation method, in the BIM-based building cantilever system installation optimization method of this embodiment. Detailed Implementation

[0027] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0028] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0029] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0030] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] Please see Figure 1 As shown, Figure 1 This is a flowchart of the BIM-based building cantilever system installation optimization method in this embodiment; This embodiment provides a BIM-based method for optimizing the installation of a building cantilever scaffolding system, including: Step S1: Construct a three-dimensional building information model of the target building based on the BIM model and the main structural data of the building containing the reverse curved slope wall; determine the cantilever installation area based on the three-dimensional building information model; and mark the three-dimensional coordinates of the initial preset installation points of the cantilever. Step S2: Construct a mechanical simulation model based on the three-dimensional coordinates and mechanical simulation software; determine the initial theoretical force value of the anchorage installation point based on the mechanical simulation model and the preset load of the cantilever frame installation area; and determine the initial installation depth of the anchorage installation point based on the initial theoretical force value. Step S3: Based on the three-dimensional coordinates, the preset installation points are actually installed to obtain the actual installation point coordinates. The three-dimensional coordinates and the actual installation point coordinates are compared to determine the number of deviation points. Based on the number of deviation points and the coordinate deviation point parameters, the deflection change of the cantilever frame is determined. Based on the deflection change of the cantilever frame, the secondary theoretical force value of the coordinate point is determined. Step S4: Determine the actual influence deviation value based on the initial theoretical force value and the secondary theoretical force value; Step S5: Determine the target installation depth or installation method based on the actual impact deviation value and the impact deviation threshold, as well as the building main structure data; The coordinate deviation point parameters include the coordinate deviation point value and the position of the deviation point; the secondary theoretical force value is positively correlated with the deflection change of the cantilever frame.

[0032] By constructing a BIM model and accurately determining the installation area, the system can fully adapt to complex building structures with walls containing reverse curved slopes. This ensures a high degree of matching between the cantilever frame installation area and the wall's spatial characteristics, avoiding installation conflicts caused by structural specialties and improving the accuracy and rationality of installation area planning. Combining mechanical simulation software to calculate initial theoretical stress values ​​and initial installation depth allows for a scientific prediction of the stress state at anchorage points, making the initial installation depth setting more closely match actual stress requirements and laying a theoretical foundation for the safety and stability of the cantilever frame system. Through comparative analysis of actual installation points and preset points, the impact of deviations on cantilever frame deflection and secondary stress is quantified, forming a closed-loop control from design to construction. This effectively identifies and assesses the risks caused by installation deviations, improving the ability to control construction accuracy. Based on the comparison of actual impact deviation values ​​and thresholds, and combined with building structure data, the target installation depth or installation method is dynamically adjusted. This can specifically address deviation exceeding limits, optimizing the economy and feasibility of the installation scheme while ensuring structural safety, ensuring safe, efficient, and precise installation of the cantilever frame system in complex wall structures.

[0033] Specifically, the process of constructing a three-dimensional building information model of the target building based on the BIM model and the building's main structural data of the reverse curved slope wall includes, Obtain the overall dimensions of the main building and the special area parameters of the reverse curved slope wall. Based on the overall dimensions and the special area parameters, determine the main building structure data. Input the main building structure data into the BIM model to obtain a three-dimensional building information model. The overall size data includes the global coordinates of the main building and the frame dimensions of the main building, while the special area parameters include the curvature of the exterior walls and the slope of the exterior walls.

[0034] Obtain the overall dimensions of the building's main structure. The global coordinates of the main building, with the construction coordinate system origin at: X=320000mm, Y=560000mm, Z=0mm. The building's plan dimensions are from 315,000 mm to 330,000 mm in the X direction, with a span of 15,000 mm; and from 555,000 mm to 570,000 mm in the Y direction, with a span of 15,000 mm. The frame dimensions of the main building, Total height: 24000mm, 6 floors in total, first floor height 5000mm, standard floor height 3800mm; Frame columns: 800mm×800mm reinforced concrete columns at the four corners, spaced 6000mm apart along the X and Y directions; Frame beam: cross-section dimensions 300mm×800mm, span 6000mm, rigidly connected to frame columns; Floor slabs: standard floor thickness 150mm, roof layer thickness 200mm, concrete strength grade C35.

[0035] Obtain the parameters of specific areas of the reverse curved slope wall. The wall is located on the south side of the building at Y=570000mm, extending from an elevation of 5000mm on the 2nd floor to an elevation of 24000mm on the 6th floor. It is a single-curved reverse slope surface. The parameters for special areas are as follows: Curvature of the exterior wall Surface type: A single-curved cylindrical surface is a straight line in the vertical direction and an arc in the horizontal direction; Radius of curvature: R=12000mm, coordinates of the center of the arc: X=322500mm, Y=582000mm, Z=0mm; Horizontal arc length: Each layer covers 9000mm along the X direction, corresponding to a central angle of approximately 43°. External wall slope value, The slope is in the opposite direction, tilting outwards along the positive Y-axis, away from the core area of ​​the building; The slope value is 1:3, meaning that for every 1000mm increase in height, the slope extends outward by 333mm. Slope variation: The slope remains constant from level 2 to level 6 without any gradual change; Additional construction parameters are used to supplement details in specific areas and ensure modeling accuracy. Wall thickness, 300mm, along the normal direction of the curved surface; Concrete strength grade: C40; higher strength is required due to reverse stress. The reserved openings include one circular window with a diameter of 1500mm on each of the 3rd to 5th floors, with center coordinates of (320000mm, 570000mm, 9000mm), (325000mm, 570000mm, 12800mm), and (320000mm, 570000mm, 16600mm) respectively. Determine the main structural data of the building and input it into the BIM model. By correlating overall dimensional data, global coordinates, frame dimensions, and specific area parameters such as curvature, slope, and thickness, a complete dataset of the building's main structure is formed. This dataset includes the spatial location and dimensions of frame columns, beams, and floor slabs, as well as the three-dimensional boundary start and end coordinates, radius of curvature, slope value, thickness, and construction details of the reverse-curved slope walls. BIM modeling, which uses software to construct 3D models, is an existing technology and will not be elaborated upon in this embodiment. Based on global coordinates and frame dimensions, draw 3D solids of columns, beams, and floor slabs, and assign them C35 concrete material; For walls with reverse curved slopes, draw a horizontal circular arc baseline with a radius of curvature R=12000mm; The baseline is stretched along the vertical Z-axis at a slope of 1:3 to form a single-curved surface profile; The wall is made of 300mm thick C40 concrete, and pre-reserved window openings are installed according to the coordinates. The wall slope was verified by measuring tools to ensure that the ratio of the height difference between any two points to the horizontal distance was 1:3 and the radius of curvature deviated from the design value by ≤5mm, thus ensuring consistency with the parameters of the special area.

[0036] The final generated 3D building information model can be intuitively displayed, showing the spatial relationship between the main building's frame structure and the reverse curved slope walls, the curvature, reverse slope, and reserved opening locations of the walls, and the material, strength, and other attributes of each component can be queried through the model attribute panel.

[0037] By integrating the overall dimensional data of the main building structure with the special regional parameters of the reverse-curved slope walls, the integrity and relevance of the main building structure data were ensured, providing a precise basis for 3D modeling. In BIM modeling, the basic form and attributes of the building frame were accurately reproduced, while detailed modeling was performed for the special structures of the reverse-curved slope walls, such as their arc features and inclined slopes. By embedding coordinates into details such as reserved openings, a precise digital representation of complex wall structures was achieved. The post-modeling verification process further ensured the consistency between the model and design parameters, enabling the generated 3D building information model to intuitively and accurately reflect the spatial relationships, structural characteristics, and material properties of various building components. This provided a reliable digital foundation for subsequent work such as determining the cantilever frame installation area and marking points, effectively improving the accuracy and efficiency of subsequent construction planning.

[0038] Specifically, the process of determining the cantilever installation area based on the three-dimensional building information model includes, The installation area of ​​the cantilever frame is determined based on the bottom elevation, top elevation, and horizontal projection range of the wall with reverse curved slope. The horizontal projection range is the horizontal projection area of ​​the reverse curved slope wall on the ground.

[0039] The building's base elevation of 5000mm corresponds to the surface of two floor slabs, and the starting point of the walls... The top elevation is 24000mm, corresponding to the 6th floor roof level, and the wall termination point. The horizontal projection range is as follows: the projection of the wall onto the ground at Z=0mm is an arc-shaped area, with the specific boundaries as follows: X direction: 315000mm-330000mm, span 15000mm; Y-direction: 570000mm-573000mm, projected width 3000mm due to the outward slope of the wall. Based on the bottom and top elevations, clearly define the vertical boundaries of the installation area. The bottom boundary, based on the wall bottom elevation of 5000mm, extends downwards by 500mm to an elevation of 4500mm, taking into account the operating space requirements of the cantilever scaffold, to ensure sufficient connection space between the bottom of the scaffold and the second-floor slab. The top boundary, based on the wall top elevation of 24000mm, extends upwards by 1000mm to an elevation of 25000mm, covering the roof layer and the exterior wall construction area. The vertical height of the installation area is 25000mm - 4500mm = 20500mm, covering the entire construction area of ​​the wall from the 2nd to the 6th floor. The horizontal boundary of the installation area is determined based on the horizontal projection range. Horizontal projection extension, based on the wall's horizontal projection range of 315000-330000mm in the X direction and 570000-573000mm in the Y direction, and considering the construction operation width, the specification requires the cantilever scaffold's outward extension width to be ≥1200mm. The X-direction should be aligned with the wall projection at 315000-330000mm. Since the wall is curved along the X-direction, the frame needs to be adapted to the curvature of the surface. The Y-axis extends 1500mm outwards in the direction of increasing Y-value to 574500mm, and 300mm inwards in the direction of decreasing Y-value to 569700mm, to avoid the connection nodes between the wall and the frame column. The final horizontal projection range is 315,000 mm to 330,000 mm in the X direction and 569,700 mm to 574,500 mm in the Y direction. Integrate 3D boundaries into the BIM model to generate the installation area. Three-dimensional spatial definition: Based on the vertical boundary of 4500mm-25000mm and the horizontal boundary X and Y ranges, a three-dimensional selection area is created. Collision detection and adjustment, The collision detection function of the BIM model revealed three circular window openings on floors 3-5, with a diameter of 1500mm. Local adjustments are needed to mark the window opening locations (e.g., Z=9000mm, X=320000mm) within a 500mm radius as a clearance zone, and the scaffolding uprights must avoid them. Inspection revealed a cantilever beam on the 6th floor with dimensions Y=570000mm, Z=22000mm, and a cantilever length of 800mm. The top boundary of the installation area was lowered from 25000mm to 21500mm to avoid conflict with the beam structure. Final installation area parameters, Vertical dimensions are 4500mm-21500mm. The horizontal dimensions are X = 315000-330000mm, Y = 569700-574500mm. In the BIM model, the final installation area is marked separately as a workset and highlighted in red. The three-dimensional coordinate data of the area boundary, such as the coordinates of each corner point and the curvature parameters of the arc boundary, are exported to provide a spatial range basis for subsequent annotation of the initial preset installation points.

[0040] By combining the elevation and horizontal projection range of the reverse-curved slope wall, the installation area was determined, ensuring full coverage of the wall construction. Reasonable vertical and horizontal expansion met the operational space requirements, allowing the cantilever scaffold to adapt to the wall's curvature and inclination. Utilizing the BIM model's collision detection function, obstacles such as window openings and cantilever beams were accurately identified and avoided, and the installation area boundaries were dynamically adjusted, effectively preventing conflicts between the scaffold and building components, and improving the feasibility and safety of the installation area. The final determined installation area, through 3D marking and data export, provided a clear and accurate spatial basis for subsequent initial pre-set installation point marking, ensuring a high degree of compatibility between the point planning and the wall structure and construction requirements, laying the foundation for precise installation of the cantilever scaffold.

[0041] Specifically, the process of marking the three-dimensional coordinates of the initial preset installation points of the cantilever frame includes, The three-dimensional coordinates of the initial preset installation point are determined and marked based on the projection point of the bottom elevation on the reverse curved slope wall and the horizontal projection area.

[0042] Based on the determined vertical range of 4500mm-21500mm and horizontal range of X=315000-330000mm and Y=569700-574500mm for the cantilever frame installation area, and combined with the bottom elevation projection points and horizontal projected area of ​​the reverse curved slope wall, the initial preset installation points are marked as follows, taking the anchorage points as an example: Determine the bottom elevation projection point and reference anchor point. The bottom elevation is projected using a baseline of 5000mm at the bottom of the wall. A horizontal baseline Z=5000mm is projected onto the wall with a reverse curved slope. The intersection of this baseline and the curved surface of the wall forms an arc with a radius of curvature R=12000mm, which serves as the vertical starting point for the initial preset installation point. For the reference anchor point setting, three bottom reference anchor points are set at 6000mm intervals along the arc-shaped baseline to match the spacing of the frame columns. The coordinates are as follows: Anchor point A1: X=318000mm, Y=570000mm, Z=5000mm corresponds to the vicinity of the second-floor frame column, avoiding the connection node between the wall and the column; Anchor point A2: X=324000mm, Y=570000mm, Z=5000mm is located in the middle of the curved section of the wall, far away from the reserved window opening; Anchor point A3: X=330000mm, Y=570000mm, Z=5000mm, near the east edge of the wall, aligned with the frame beam. Based on the horizontal projection area, the vertical points are expanded. Based on the cantilever frame step distance requirement of 1500mm / step, starting from the bottom reference anchor point and extending upwards along the vertical Z-axis of the wall, and considering the horizontal projection range X=315000-330000mm and Y=569700-574500mm, a vertical anchor point is set directly above each reference anchor point. Anchor point A1 is placed every 1500mm along the Z-axis upwards: A1-1, 318000mm, 570000mm, 6500mm A1-2, 318000mm, 570000mm, 8000mm lower than the 3rd floor window opening Z=9000mm, 1000mm from the edge of the window opening; A1-3, 318000mm, 570000mm, 9500mm higher than the 3rd floor window opening by 500mm, avoiding the opening area; And so on, until the top boundary at Z=21500mm. Anchor point A2 should be set similarly, but it must avoid the 4th floor window opening Z=12800mm. A2-1, 324000mm, 570000mm, 6500mm, A2-2, 324000mm, 570000mm, 12000mm lower than the 4th floor window opening by 800mm; A2-3, 324000mm, 570000mm, 13500mm higher than the 4th floor window opening by 700mm; Anchor point A3 avoids the 5th floor window opening Z=16600mm: A3-1, 330000mm, 570000mm, 6500mm, A3-2, 330000mm, 570000mm, 16000mm, 600mm lower than the 5th floor window opening; A3-3, 330000mm, 570000mm, 17500mm higher than the 5th floor window opening by 900mm. In the BIM model, assign a unique ID to all the aforementioned initial preset installation points, such as A1-1, A2-2, etc., and record their three-dimensional coordinates in the model properties panel with an accuracy of 1mm. When annotating, simultaneously associate the local properties of the reverse curved slope wall, for example: For anchor point A1, mark the wall curvature R=12000mm, slope 1:3 and concrete strength C40 at the location; For anchor points near window openings, such as A1-3, mark a distance of 500mm from the edge of the window opening on the 3rd floor as a reminder for subsequent stress calculations. Step 4: Verify the rationality of the location Check using the distance measurement tool in the BIM model. The horizontal spacing between adjacent anchor points is 6000mm, matching the spacing between frame columns to ensure uniform stress distribution; All locations are ≥500mm away from the edge of the reserved window opening, meeting the specification requirements; The Z-coordinates of all points are within 4500mm-21500mm of the vertical boundary of the installation area, and the step distance of 1500mm conforms to the cantilever scaffold erection specifications.

[0043] Using the bottom elevation projection point as a benchmark, and combining the horizontal projection area to expand the vertical points, the initial preset installation point distribution is designed to adapt to the arc and tilt characteristics of the reverse curved slope wall, and also match the building frame structure, such as the spacing of the frame columns, ensuring the rationality of the point layout. During annotation, information such as the local characteristics of the wall and the distance to window openings is simultaneously linked, providing a direct reference for subsequent stress calculations and facilitating accurate assessment of the stress state at each point. The BIM model verifies the point spacing, distances to obstacles, and coordinate range, ensuring that all points meet construction specifications and safety requirements. This avoids installation conflicts or uneven stress caused by improper point placement, providing a reliable coordinate basis for the safe and accurate installation of the cantilever frame, and improving the scientific nature and efficiency of construction planning.

[0044] Specifically, the process of determining the initial theoretical force value of the anchorage installation point based on the mechanical simulation model and the preset load of the cantilever frame installation area includes: Input the preset load into the mechanical simulation model to obtain the initial theoretical force value at the anchorage installation point; The preset load includes the structural load of the cantilever frame itself, the construction load, and the additional load.

[0045] Based on the existing 3D building information model and the vertical dimensions of the cantilever installation area (4500mm-21500mm), and the horizontal dimensions (X=315000-330000mm, Y=569700-574500mm), mechanical simulation software was used for analysis. In this embodiment, the ANSYS mechanics simulation software is used. A mechanical simulation model was constructed and the geometric features of the wall were input. The core data of the BIM model was imported into the mechanical simulation software, and the reverse curved slope wall was simplified into a three-dimensional solid model, retaining key parameters. A horizontal circular arc with a curvature R=12000mm and a vertical inclination of 1:3; Material: C40 concrete; Elastic modulus: 3.25 × 10⁻⁶ 4 MPa, Poisson's ratio 0.2; Boundary conditions: The bottom of the wall, Z=5000mm, is rigidly connected to the second floor slab, constraining displacement in the X, Y, and Z directions; the top, Z=21500mm, is a free end.

[0046] The simulated anchor point connection method uses pre-embedded parts welded to the bottom reference anchor points such as A1, A2, and A3. A 10mm thick steel plate, made of Q235 steel, is pre-embedded in the wall in the model. The steel plate is welded to the cantilever beam, which is made of No. 16 I-beam. The relative displacement constraint stiffness between the steel plate and the wall is taken as 1×10⁻⁶. 5 N / mm; For vertical expansion points such as A1-1 and A2-2, M20 chemical anchors are used for connection, simulating the bond between the anchors and the wall, with a shear stiffness of 5×10⁻⁶. 4 N / mm, tensile stiffness is taken as 3×10 4 N / mm, The preset load is determined based on the construction complexity of the reverse curved slope wall. Due to the complexity of constructing a reverse-sloping wall surface, including its curvature and reverse inclination, the operation is more difficult than that of a flat wall. The preset load values ​​are as follows. The structural load of the cantilever frame itself, Self-weight of the frame: Based on the uprights, the uprights are calculated as a combination of Φ48×3.5mm steel pipes, horizontal bars, and scaffold boards. The uniformly distributed load is 0.7kN / m, which is 10% higher than that of the flat frame. Due to the curvature, additional connecting parts are required. Self-weight of the cantilever beam: Calculated at 0.205 kN / m for a No. 16 I-beam. Considering the need for curved cutting and processing, an additional 15% weight is added, resulting in an actual weight of 0.236 kN / m. Construction load, Live load, taken as 2.5 kN / m, due to the frequent movement of tools and materials required for curved wall construction. 2 The strength of a standard flat wall is 2.0 kN / m. 2 ; Personnel load, based on 2 people / m 2 Converted from 70kg / person to 9.8N / kg, we get 1.37kN / m. 2 ; Additional load, Wind load, building height 21.5m, basic wind pressure 0.55kN / m2 The wind load factor for curved walls is taken as 1.3, and for flat walls as 1.0. The calculated wind load is 1.3 × 0.55 = 0.715 kN / m. 2 ; Temporary storage load: Considering the inconvenience of transporting construction materials on curved surfaces, local storage of 3kN / m is permitted. 2 Limited to a 3m x 3m area. Calculate the initial theoretical force values. In the mechanical simulation model, uniformly distributed loads, self-loads, and construction live loads are applied to the cantilever area according to the above load values. Due to limited operating space, a localized application of 3kN / m is applied around the window openings on the 3rd to 5th floors. 2 Temporary storage load; A wind load of 0.715 kN / m is applied to the outer side of the wall along the positive Y-axis. 2 , Output the initial theoretical force values. Through simulation calculations, the initial theoretical force values ​​at typical anchorage points are as follows: Welding of the embedded part at the bottom reference anchor point A1 The axial tensile force F = 18.5 kN, the shear force V = 12.3 kN, and the bending moment M = 7.8 kN·m are located at the root of the cantilever frame and bear the main load. Vertical extension point A2-2 chemical anchor, The axial tensile force F = 9.2 kN, the shear force V = 6.5 kN, and the bending moment M = 3.1 kN·m are located in the middle and are subjected to less stress than at the root. Top point A3-3 chemical anchor: The axial tensile force F = 5.7 kN, the shear force V = 8.9 kN, and the bending moment M = 2.3 kN·m. Due to the influence of the reverse slope, the shear force increases.

[0047] By importing core data from the BIM model into mechanical simulation software, the geometric features, material properties, and anchorage connection methods of the reverse curved slope wall are accurately reproduced, providing a realistic model foundation for stress analysis. Considering the high complexity of curved wall construction, preset loads, including the self-weight of the scaffold, construction loads, and additional loads, are rationally determined, fully taking into account special factors such as surface adaptation and operational difficulty, making the load values ​​more consistent with actual construction scenarios. Simulation calculations yield the initial theoretical stress values ​​for each anchorage point, clearly showing the stress differences at different locations, such as the root and top, and points with different connection methods. This provides a scientific basis for determining the initial installation depth, ensuring that the anchorage design can effectively cope with complex stress states and improving the safety and reliability of the cantilever scaffold system.

[0048] Specifically, the process of determining the initial installation depth of the anchorage installation point based on the initial theoretical force value includes, The initial installation depth is determined based on the initial force value and the installation depth coefficient. The installation depth coefficient is a compensation parameter for the influence of the initial stress value on the initial installation depth. The initial stress value is positively correlated with the initial installation depth. The installation depth coefficient is determined based on the concrete strength grade and the thickness of the reverse curved slope wall in the main structure data.

[0049] Taking the anchorage points of a reverse-curved slope wall, such as the bottom reference anchor point A1 and the vertical extension point A2-2, as an example, the initial installation depth is calculated based on its initial theoretical stress value and installation depth coefficient. Initial theoretical force value, The bottom reference anchor point A1 is pre-embedded and welded, with an axial tensile force F1=18.5kN and a shear force V1=12.3kN; Vertical extension point A2-2, M20 chemical anchor, axial tensile force F2=9.2kN, shear force V2=6.5kN; Based on the building's main structural data, the concrete strength grade is C40, the wall thickness is 300mm with a reverse curved slope, and the stress type is primarily tensile, the coefficients are determined accordingly. For concrete strength correction, the benchmark value for the installation depth coefficient of C40 concrete is 0.012mm / N, and that of C30 is 0.015mm / N. The higher the strength, the smaller the coefficient, because the material has a stronger load-bearing capacity. Wall thickness correction: The wall thickness is 300mm, which is greater than the usual 250mm. The coefficient is reduced by 10%, and the corrected value is 0.012×0.9=0.0108mm / N. The final installation depth coefficient is 0.0108 mm / N for anchor points controlled by tensile force. If shear force is the main factor, the coefficient needs to be increased by 20%, because shear force is more sensitive to depth. Initial installation depth = initial theoretical axial tensile force × installation depth coefficient Since axial tensile force is the main risk factor for anchorage failure, tensile force is used as the control indicator. Welding of the embedded part at the bottom reference anchor point A1 Initial installation depth H1 = 18.5kN × 1000N / kN × 0.0108mm / N = 199.8mm ≈ 200mm; Verify that the wall thickness is 300mm, and the installation depth is 200mm < 300mm × 2 / 3, which meets the requirement of a protective layer ≥ 50mm. 300 - 200 = 100mm ≥ 50mm. Vertical extension point A2-2, M20 chemical anchor. Initial installation depth H2 = 9.2kN × 1000N / kN × 0.0108mm / N = 99.36mm ≈ 100mm; The minimum anchoring depth requirement for M20 chemical anchors is 200mm. In this embodiment, since A2-2 is the middle point, the stress is small, and the bonding force of the chemical anchors is evenly distributed. Combined with the wall thickness of 300mm, a depth of 100mm meets the structural requirement of anchoring depth ≥100mm. At the same time, a 200mm protective layer is reserved (300-100=200mm), which provides sufficient safety redundancy. The initial installation depth at special locations should be adjusted taking into account the influence of shear force. For points with a high proportion of shear force, such as the top point A3-3, where the shear force V = 8.9 kN, the installation depth coefficient needs to be increased by 20% based on the shear force correction. The corrected coefficient is 0.0108 × 1.2 = 0.01296 mm / N; The initial installation depth H3 = 8.9kN × 1000 × 0.01296 ≈ 115.3mm ≈ 120mm, which also meets the depth requirements for tensile force control.

[0050] By combining the initial theoretical stress value with the installation depth coefficient to determine the initial installation depth, a precise match between stress requirements and installation depth is achieved. The positive correlation between the initial stress value and installation depth ensures sufficient depth support at points under high stress, enhancing anchoring safety. The installation depth coefficient is dynamically adjusted based on the concrete strength grade and wall thickness, fully considering the impact of material properties and structure on anchoring effectiveness, making the coefficient value more closely reflect actual working conditions. Correction coefficients for different stress types, such as predominantly tensile or shear force, further improve the targeting and accuracy of installation depth calculations. Verification of the compatibility of installation depth with wall thickness and protective layer requirements, as well as depth adjustments for special points, ensures that the initial installation depth meets both stress requirements and construction specifications, providing crucial assurance for the stability and reliability of anchoring points and offering a scientific quantitative basis for subsequent actual installation.

[0051] Please see Figure 2 , Figure 2 This is a flowchart illustrating the process of determining the number of deviation points in the BIM-based building cantilever system installation optimization method of this embodiment. Specifically, the process of comparing the three-dimensional coordinates with the actual installation point coordinates to determine the number of deviation points includes, Planar deviation and elevation deviation are obtained based on three-dimensional coordinates and actual installation point coordinates, and the comprehensive deviation is determined based on the plane deviation and elevation deviation. Based on the plane deviation and the plane deviation threshold, the plane deviation comparison results and the plane coordinate deviation point parameters are obtained; The elevation deviation comparison results and elevation coordinate deviation point parameters are obtained based on the elevation deviation and elevation deviation threshold. Based on the comprehensive deviation and the comprehensive deviation threshold, the comprehensive deviation comparison results and the comprehensive coordinate deviation point parameters are obtained; If the plane deviation is greater than the plane deviation threshold, or the elevation deviation is greater than the elevation deviation threshold, or the combined deviation is greater than the combined deviation threshold, then the point is a deviation point. The number of deviation points is counted and obtained.

[0052] Obtain the 3D coordinates and the actual installation point coordinates. Initial preset 3D coordinates Anchor point A1, X0=318000mm, Y0=570000mm, Z0=5000mm. Anchor point A2-2, X0=324000mm, Y0=570000mm, Z0=12000mm. Anchor point A3-3, X0=330000mm, Y0=570000mm, Z0=17500mm. The actual installation point coordinates were measured on-site using a total station. Actual A1', X1=318025mm, Y1=570015mm, Z1=5010mm, In actual configuration A2-2`, X1=324010mm, Y1=570008mm, Z1=12005mm. In actual dimensions A3-3', X1=330035mm, Y1=570020mm, Z1=17525mm. Calculate the plane deviation, elevation deviation, and overall deviation. Planar deviation ∆S reflects the horizontal deviation in the X and Y directions. ; A1`: ∆S1≈29.15mm, A2-2`: ∆S2≈12.8mm, A3-3`: ∆S3≈40.31mm, The elevation deviation ∆H reflects the vertical deviation in the Z direction. ∆H=|Z1-Z0|, A1`: ΔH1=|5010-5000|=10mm, A2-2`: ΔH2=|12005-12000|=5mm, A3-3`: ΔH3=|17525-17500|=25mm, The overall deviation ∆T reflects the total deviation in three-dimensional space. , A1`: ∆T1≈30.82mm, A2-2`: ∆T2≈13.75mm, A3-3`: ∆T3≈47.43mm, The calculation steps are existing technology and will not be elaborated here. Based on the curvature R=12000mm of the reverse-sloping wall and industry standards, a threshold is set. The plane deviation threshold is set to 25mm, but since the radius of curvature is greater than 8m, the standard value is 30mm. The elevation deviation threshold is set to 20mm, and the slope ratio is 1:3 ≤ 1:2.5, taking the upper limit of the conventional value. The overall deviation threshold is set at 35mm, a combined control value for both horizontal and vertical thresholds. By comparing the deviation with the threshold, the location of the deviation can be determined. Planar deviation comparison, A1`, 29.15mm > 25mm, plane deviation exceeds the standard. A2-2`, 12.8mm < 25mm, plane deviation is acceptable. A3-3`, 40.31mm > 25mm, plane deviation exceeds the standard. Elevation deviation comparison A1`, 10mm < 20mm, elevation deviation is acceptable. A2-2`, 5mm < 20mm, elevation deviation is acceptable. A3-3`, 25mm > 20mm, elevation deviation exceeds standard. Overall deviation comparison, A1`, 30.82mm < 35mm, overall deviation is acceptable. A2-2`, 13.75mm < 35mm, overall deviation is acceptable. A3-3`, 47.43mm > 35mm, overall deviation exceeds the standard. A1`, Planar deviation exceeds standard, deviation point. A2-2', all deviations are within acceptable limits; non-deviation points are not included. A3-3', the horizontal, vertical, and overall deviations all exceed the standards; deviation points are located... In this embodiment, a total of 3 points are detected, of which A1` and A3-3` are deviation points, so the number of deviation points is 2.

[0053] By calculating planar deviation, elevation deviation, and comprehensive deviation separately, the deviation of actual installation points in three-dimensional space is comprehensively considered, avoiding the limitations of single-dimensional evaluation and making the deviation analysis more comprehensive and accurate. Deviation thresholds are set based on the structural characteristics of the reverse-curved slope wall, such as curvature and slope, ensuring that the threshold standards are compatible with the special structure of the wall and improving the rationality and specificity of deviation judgment. By statistically analyzing the number of deviation points, the overall installation accuracy can be intuitively grasped, laying a data foundation for subsequent deflection change calculations and installation scheme optimization, and facilitating refined control of the construction process.

[0054] Specifically, the process of determining the deflection change of the cantilever frame based on the number of deviation points and the coordinate deviation point parameters includes, The weighting parameter of the coordinate deviation point on the change in cantilever deflection is determined based on its location, and the change in cantilever deflection is determined based on the weighting parameter and the number of deviation points.

[0055] Location and attributes of deviation points A1`, the bottom reference anchor point Z=5000mm, is located at the root of the cantilever frame and bears the main vertical load. The plane deviation of 29.15mm exceeds the standard, while the elevation deviation of 10mm is acceptable. A3-3`, with its top point Z=17500mm, is located at the end of the cantilever frame. Due to the reverse slope, it experiences significant shear force, exceeding the standard with a planar deviation of 40.31mm and an elevation deviation of 25mm. Deviation point value, Planar deviation values: A1` = 29.15 mm, A3-3` = 40.31 mm. The elevation deviation values ​​A1` = 10mm are within the acceptable range and are not included in the weighting; however, A3 - 3` = 25mm exceeds the acceptable range. The deflection of the cantilever frame is caused by the combined effect of deviations at each anchorage point. The deviation at the root point has a greater impact on the deflection, similar to the lever principle, where the root is the fulcrum. Therefore, weights are assigned according to the location. Position weight coefficient k1, The bottom point A1` is located at the root of the cantilever frame, ≤1 / 3 of the frame height from the fixed end, and plays a decisive role in the overall deflection. The weighting coefficient k11=0.6 is set. The top point A3-3' is located at the end of the cantilever frame, more than 2 / 3 of the frame height from the fixed end, affecting the local deflection. The weighting coefficient k12 = 0.4. The deviation weighting coefficient k2, The larger the deviation, the more significant the impact on deflection. This is calculated as the ratio of actual deviation to the threshold. A1' plane deviation is 29.15mm / 25mm = 1.166, so we take k21 = 1.166; A3-3` The combined deviation of plane and elevation (40.31mm / 25mm) + (25mm / 20mm) = 1.612 + 1.25 = 2.862. Taking k22 = 2.862, since both deviations exceed the standard, they are calculated by adding them together. Single-point weight parameter k, Weight parameter = position weight coefficient × deviation degree weight coefficient The weight parameter of A1` is approximately 0.7 (0.6 × 1.166). The weight parameter of A3-3' is approximately 1.145 (0.4 × 2.862). According to the mechanical simulation model, the design deflection of the cantilever frame under no-deviation conditions is generated by a preset load of f0 = 15mm, which meets the specification requirement of ≤L / 250, where L is the cantilever length. The effect of single-point deflection ∆fi, The impact of deviation points on deflection is positively correlated with the weighting parameters. ∆fi=f0×(ki / ∑ki)×(number of deviation points / total number of points) The total weight ∑ki = 0.7 + 1.145 = 1.845; Total number of points: 3 (A1, A2-2, A3-3), number of deviation points: 2. The effect of A1' on deflection ∆f1=15mm×(0.7 / 1.845)×2 / 3=15×0.379×0.667≈3.79mm; The effect of A3-3' on deflection ∆f2=15mm×1.145 / 1.845×2 / 3=15×0.621×0.667≈6.21mm, The total deflection change ∆f = ∆f1 + ∆f2 = 3.79 mm + 6.21 mm = 10 mm.

[0056] The standard requires that the allowable increase in the deflection of the cantilever scaffold be ≤ 50% of the original design deflection, i.e. ≤ 7.5mm; The calculation result ∆f=10mm>7.5mm indicates that the deviation point caused the deflection to exceed the limit, and it needs to be optimized in subsequent steps by adjusting the installation depth or method.

[0057] By assigning different weight parameters to the locations of deviation points, the difference in the impact of root and end points on the cantilever deflection is fully considered, conforming to the principle of the fulcrum effect in structural mechanics and making the weight allocation more consistent with the actual stress logic. Calculating the weight parameters in conjunction with the degree of deviation demonstrates the positive correlation between the magnitude of the deviation and the impact on deflection. In particular, the superposition calculation for points with multiple deviations exceeding the limit enhances the accuracy of the deflection analysis. Combining the weight parameters with the number of deviation points to calculate the total deflection change comprehensively considers the distribution range and degree of influence of the deviations, scientifically quantifying the effect of installation deviations on the cantilever deformation. By comparing with the allowable values ​​in the specifications, it is possible to clearly determine whether the deflection exceeds the limit, providing a direct basis for subsequent adjustments to the installation plan. This helps to promptly avoid structural safety risks caused by excessive deflection and ensures the stability of the cantilever system.

[0058] Please see Figure 3 , Figure 3 This is a flowchart illustrating the process of determining the actual impact deviation value in the BIM-based building cantilever system installation optimization method of this embodiment. Specifically, the process of determining the actual influence deviation value based on the initial theoretical force value and the secondary theoretical force value includes, Based on the comparison results of the initial theoretical force value and the secondary theoretical force value, the actual influence deviation value is determined. If the initial theoretical force value is greater than or equal to the secondary theoretical force value, then the actual influence deviation value is the initial influence deviation value. Since the initial theoretical force value is less than the secondary theoretical force value, the actual influence deviation value is determined based on the difference between the secondary theoretical force value and the initial theoretical force value. The initial theoretical stress value is determined based on the maximum stress value at the anchorage installation point; the initial influence deviation value is a preset stress fluctuation benchmark value, determined according to the first-level safety level of the main building structure.

[0059] In this embodiment, the first-level deviation threshold is less than the second-level deviation threshold, which is less than the third-level deviation threshold. The initial theoretical force values ​​were taken from mechanical simulation results, using the control values ​​among the maximum force values ​​of axial tension, shear force, and bending moment at each anchorage point as benchmarks. The A1 bottom reference anchor point has a maximum axial tensile force of 18.5 kN, which is a core indicator for controlling the installation depth. At the top point of A3-3, the maximum force is a shear force of 8.9 kN. Due to the influence of the reverse slope, the shear force accounts for the highest proportion. The secondary theoretical stress value is positively correlated with the change in cantilever deflection; an increase in deflection leads to additional stress. F = F0 × (1 + ∆f / f0), Where f0 = 15 mm reference deflection value, and ∆f = 10 mm deflection change. The secondary theoretical force value of A1, F11=18.5kN×(1+10mm / 15mm)=18.5×(1+0.667)≈30.83kN; The secondary theoretical force values ​​of A3-3: F13=8.9kN×(1+10mm / 15mm)=8.9×1.667≈14.84kN, The initial influence deviation value is a pre-set stress fluctuation benchmark value based on the first-level safety level of the main building structure. This benchmark value is determined according to the ultimate limit state requirements for the bearing capacity of first-level safety level structures in the "Unified Standard for Reliability Design of Building Structures" (GB 50068). Specifically, the value is 5% of the standard value of the design bearing capacity of the cantilever anchorage system, and not less than 3kN, which is used to define the allowable threshold for stress fluctuation. Initial influence deviation ∆0 = 5%, allowable force fluctuation ≤ 5%. By comparing the initial and secondary theoretical force values, the actual influence deviation value is determined. Comparison of stress values: A1: F1 = 18.5 kN < F11 = 30.83 kN, the initial force is less than the secondary force. A3-3: F3 = 8.9kN < F13 = 14.84kN, the initial force value is less than the secondary force value. When the initial theoretical force value is less than the secondary theoretical force value, the actual influence deviation value is calculated as a percentage of the difference. ∆=[(F1-F0) / F]×100%, The actual impact deviation value of A1, ∆1 = [(30.83 - 18.5) / 18.5] × 100% ≈ 66.6%; The actual impact deviation value of A3-3, ∆3=[(14.84-8.9) / 8.9]×100%≈66.7%.

[0060] Using the maximum stress value at the anchorage point as the initial theoretical stress value benchmark, the core indicators for controlling installation safety are precisely identified, ensuring the targeted nature of the stress analysis. By establishing a positive correlation between the secondary theoretical stress value and the change in deflection, the additional stress caused by installation deviations is quantified, clearly demonstrating the impact of deviations on structural stress. The actual impact deviation value is dynamically determined based on the comparison between the initial stress value and the secondary theoretical stress value. When the stress value increases, it is calculated as a percentage of the difference, objectively reflecting the stress increase caused by the deviation and avoiding the limitations of fixed deviation values ​​that are difficult to adapt to actual working conditions. The initial impact deviation value is set in conjunction with the building's main safety level, providing a reasonable benchmark for deviation assessment. The final actual impact deviation value can intuitively determine whether the stress exceeds the limit, providing a clear quantitative basis for subsequent adjustments to the installation depth or method, and helping to ensure the stress safety of the cantilever system under complex working conditions.

[0061] Please see Figure 4 , Figure 4 This is a flowchart illustrating the process of determining the target installation depth, or installation method, in the BIM-based building cantilever system installation optimization method of this embodiment. Specifically, the process of determining the target installation depth, or installation method, based on the actual impact deviation value and the impact deviation threshold, as well as the building's main structural data, includes: Based on the fact that the actual impact deviation value is less than or equal to the first-level deviation threshold, the current installation depth and installation method shall be maintained. Based on the actual impact deviation value being greater than the first-level deviation threshold and less than the second-level deviation threshold, the maximum allowable installation depth at the current location is determined based on the building's main structural data. The target installation depth is determined based on the difference between the initial installation depth, the second-level deviation threshold, and the actual impact deviation value. The installation method is determined based on the comparison between the target installation depth and the maximum allowable installation depth. If the actual impact deviation value is greater than or equal to the third-level deviation threshold, the installation method is determined based on the difference between the actual impact deviation value and the third-level deviation threshold. The installation methods include chemical anchor bolt anchoring, pre-embedded component welding, and combined anchoring.

[0062] Given actual impact deviation values ​​A1 = 66.6%, A3-3 = 66.7%, building structure data: wall thickness 300mm, concrete strength C40; set impact deviation thresholds: Level 1 deviation threshold 5%, Level 2 deviation threshold 30%, Level 3 deviation threshold 60%. Chemical anchors are suitable for applications with low stress and small deviations, such as initial installation of M20 chemical anchors. Welding of embedded parts is suitable for situations where the stress is large and the shear and bending resistance needs to be improved, such as at the bottom root point. Combination anchoring with chemical anchors and steel plates is suitable for situations where deviations exceed limits, including reaching the third-level deviation threshold. The steel plate enhances the integrity of the anchors and the wall, improving pull-out and shear resistance. Compare the actual impact deviation value with the deviation threshold. The actual impact deviation value is 20% for anchorage point B2-1, which is located in the middle of the reverse curved slope wall. The original installation method for B2-1 was M20 chemical anchors, with an initial installation depth of 100mm. Determine the maximum allowable installation depth at the current location based on the building's main structural data. The wall thickness is 300mm. The standard requires the installation depth to be ≤2 / 3 of the wall thickness to avoid wall splitting. Therefore, the maximum allowable installation depth is 300mm×2 / 3=200mm. Since the protective layer thickness must be ≥50mm, the maximum allowable installation depth is determined to be 200mm. Calculate the target installation depth. Calculate the deviation difference: Secondary deviation threshold - actual impact deviation value = 10%; The target installation depth is the initial installation depth × (1 + deviation difference), i.e., 100mm × (1 + 10%) = 110mm. The larger the deviation difference, the greater the required depth to compensate for the stress deviation. Compare the target installation depth with the maximum allowable installation depth to determine the installation method. The target installation depth is less than the maximum allowable installation depth, and the limit is not exceeded. Since the target depth is within the allowable range and the actual impact deviation does not reach the level three threshold, there is no need to change the installation method; only the depth needs to be adjusted. Therefore, the M20 chemical anchor bolt anchoring method will be maintained, and the depth will be increased from 100mm to 110mm. A depth of 110mm satisfies the minimum anchoring requirement of ≥100mm for M20 chemical anchors. C40 concrete provides sufficient bond strength to ensure that the adjusted anchor bolt shear and tensile bearing capacity covers the secondary theoretical stress value; With the increase in depth, the fit with the reverse curved wall was not affected, and there was no risk of stress concentration. A1 bottom reference anchor point, 66.6% greater than or equal to the third-level deviation threshold; At the top point of A3-3, 66.7% are greater than or equal to the third-level deviation threshold; Since the actual impact deviation values ​​at both locations reach the level three threshold, the installation method needs to be determined based on the difference between the actual impact deviation value and the level three deviation threshold. Deviation difference A1, 66.6% - 60% = 6.6%; A3-3, 66.7% - 60% = 6.7%, Determine the installation method. When the difference is ≤10%, combined anchoring is adopted, utilizing the synergistic effect of chemical anchors and steel plates to replace larger diameter anchors and meet the specified requirements. The original installation method for A1 involved welding the embedded parts to an initial depth of 200mm. Due to a deviation of 6.6%, a 10mm thick annular steel plate was added to surround the embedded parts, forming a combined anchorage. The steel plate was fully welded to the embedded parts and further secured to the wall using chemical anchors. Four additional M16 chemical anchors were distributed around the circumference of the steel plate to enhance bending moment resistance and improve overall rigidity. The original installation method for A3-3 involved M20 chemical anchors with an initial depth of 120mm. A combined anchoring method was adopted, retaining the M20 chemical anchors and deepening them to 150mm. An 8mm thick curved steel plate was added to the perimeter, prefabricated according to the wall curvature. The steel plate was welded to the anchors and bonded to the wall for fixation, thereby improving shear bearing capacity and covering a secondary theoretical stress value of 14.84kN. The wall thickness is 300mm. In the A3-3 combination anchoring, the M20 chemical anchor is 150mm deep and less than 300mm×2 / 3. The protective layer is 150mm and ≥50mm. The steel plate thickness is 8mm and the anchor diameter is 20mm. The total thickness does not exceed the safe range of the wall. With concrete strength C40, after A1 combination anchoring, the pull-out bearing capacity of the embedded part plus steel plate is increased to meet the secondary theoretical stress value of 30.83kN; The A3-3 curved steel plate with reverse curved surface characteristics fits perfectly with the curved surface of the wall with an arc error of ≤3mm, avoiding local stress concentration.

[0063] By employing a tiered processing strategy based on the actual impact deviation values ​​in different ranges, the installation scheme can be finely adjusted. When the deviation value is between the first and second level thresholds, the target installation depth is calculated and compared with the maximum allowable depth. Adjusting only the depth without changing the installation method compensates for stress deviations while fully utilizing the load-bearing potential of the wall structure, balancing safety and economy. When the deviation value reaches the third level threshold, a combined anchoring method is adopted. The synergistic effect of steel plates and anchors enhances the overall rigidity and load-bearing capacity, adapting to the complex stress requirements of walls with reverse curved slopes. Simultaneously, the installation scheme is verified using data from the main building structure to ensure that the adjusted depth and method meet the limitations of wall thickness and concrete strength, avoiding structural damage. The curved steel plate, customized for the characteristics of reverse curved surfaces, ensures a close fit to the wall, reduces stress concentration, and makes the anchoring system more adaptable to the mechanical characteristics of curved structures. This tiered adjustment mechanism comprehensively covers the processing needs of different deviation levels, effectively balancing safety, economy, and adaptability, and improving the reliability and stability of the cantilever system in complex wall structures.

[0064] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A BIM-based building falsework system installation optimization method, characterized in that, include, A three-dimensional building information model of the target building is constructed based on the BIM model and the main structural data of the building containing the reverse curved slope wall. The cantilever installation area is determined based on the three-dimensional building information model, and the three-dimensional coordinates of the initial preset installation points of the cantilever are marked. A mechanical simulation model is constructed based on the three-dimensional coordinates and mechanical simulation software. The initial theoretical force value of the anchorage installation point is determined based on the mechanical simulation model and the preset load of the cantilever frame installation area. The initial installation depth of the anchorage installation point is determined based on the initial theoretical force value. Based on the three-dimensional coordinates, the preset installation points are actually installed to obtain the actual installation point coordinates. The three-dimensional coordinates and the actual installation point coordinates are compared to determine the number of deviation points. Based on the number of deviation points and the coordinate deviation point parameters, the deflection change of the cantilever frame is determined. Based on the deflection change of the cantilever frame, the secondary theoretical force value of the coordinate point is determined. The actual influence deviation value is determined based on the initial theoretical force value and the secondary theoretical force value. The target installation depth or installation method is determined based on the actual impact deviation value and the impact deviation threshold, as well as the building main structure data. The coordinate deviation point parameters include the coordinate deviation point value and the position of the deviation point; the secondary theoretical force value is positively correlated with the deflection change of the cantilever frame.

2. The BIM-based building falsework system installation optimization method of claim 1, wherein, The process of constructing a 3D building information model of the target building based on the BIM model and the building structure data of the reverse curved slope wall includes, Obtain the overall dimensions of the main building and the special area parameters of the reverse curved slope wall. Based on the overall dimensions and the special area parameters, determine the main building structure data. Input the main building structure data into the BIM model to obtain a three-dimensional building information model. The overall size data includes the global coordinates of the main building and the frame dimensions of the main building, while the special area parameters include the curvature of the exterior walls and the slope of the exterior walls.

3. The BIM-based building cantilever system installation optimization method according to claim 2, characterized in that, The process of determining the cantilever installation area based on the aforementioned 3D building information model includes: The installation area of ​​the cantilever frame is determined based on the bottom elevation, top elevation, and horizontal projection range of the wall with reverse curved slope. The horizontal projection range is the horizontal projection area of ​​the reverse curved slope wall on the ground.

4. The BIM-based building cantilever system installation optimization method according to claim 3, characterized in that, The process of marking the three-dimensional coordinates of the initial preset installation points of the cantilever frame includes, The three-dimensional coordinates of the initial preset installation point are determined and marked based on the projection point of the bottom elevation on the reverse curved slope wall and the horizontal projection area.

5. The BIM-based building cantilever system installation optimization method according to claim 4, characterized in that, The process of determining the initial theoretical force value of the anchorage installation point based on the mechanical simulation model and the preset load of the cantilever frame installation area includes, Input the preset load into the mechanical simulation model to obtain the initial theoretical force value at the anchorage installation point; The preset load includes the structural load of the cantilever frame itself, the construction load, and the additional load.

6. The BIM-based building cantilever system installation optimization method according to claim 5, characterized in that, The process of determining the initial installation depth of the anchorage installation point based on the initial theoretical force value includes, The initial installation depth is determined based on the initial force value and the installation depth coefficient. The installation depth coefficient is a compensation parameter for the influence of the initial stress value on the initial installation depth. The initial stress value is positively correlated with the initial installation depth. The installation depth coefficient is determined based on the concrete strength grade and the thickness of the reverse curved slope wall in the main structure data.

7. The BIM-based building cantilever system installation optimization method according to claim 6, characterized in that, The process of comparing the three-dimensional coordinates with the actual installation point coordinates to determine the number of deviation points includes, Planar deviation and elevation deviation are obtained based on three-dimensional coordinates and actual installation point coordinates, and the comprehensive deviation is determined based on the plane deviation and elevation deviation. Based on the plane deviation and the plane deviation threshold, the plane deviation comparison results and the plane coordinate deviation point parameters are obtained; The elevation deviation comparison results and elevation coordinate deviation point parameters are obtained based on the elevation deviation and elevation deviation threshold. Based on the comprehensive deviation and the comprehensive deviation threshold, the comprehensive deviation comparison results and the comprehensive coordinate deviation point parameters are obtained; If the plane deviation is greater than the plane deviation threshold, or the elevation deviation is greater than the elevation deviation threshold, or the combined deviation is greater than the combined deviation threshold, then the point is a deviation point. The number of deviation points is counted and obtained.

8. The BIM-based building cantilever system installation optimization method according to claim 7, characterized in that, The process of determining the deflection change of the cantilever frame based on the number of deviation points and the coordinate deviation point parameters includes: The weighting parameter of the coordinate deviation point on the change in cantilever deflection is determined based on its location, and the change in cantilever deflection is determined based on the weighting parameter and the number of deviation points.

9. The BIM-based building cantilever system installation optimization method according to claim 8, characterized in that, The process of determining the actual influence deviation value based on the initial theoretical force value and the secondary theoretical force value includes, Based on the comparison results of the initial theoretical force value and the secondary theoretical force value, the actual influence deviation value is determined. If the initial theoretical force value is greater than or equal to the secondary theoretical force value, then the actual influence deviation value is the initial influence deviation value. Since the initial theoretical force value is less than the secondary theoretical force value, the actual influence deviation value is determined based on the difference between the secondary theoretical force value and the initial theoretical force value. The initial theoretical stress value is determined based on the maximum stress value at the anchorage installation point; the initial influence deviation value is a preset stress fluctuation benchmark value, determined according to the first-level safety level of the main building structure.

10. The BIM-based building cantilever system installation optimization method according to claim 9, characterized in that, The process of determining the target installation depth, or the installation method, based on the actual impact deviation value and the impact deviation threshold, and the building structure data, includes... Based on the fact that the actual impact deviation value is less than or equal to the first-level deviation threshold, the current installation depth and installation method shall be maintained. Based on the actual impact deviation value being greater than the first-level deviation threshold and less than the second-level deviation threshold, the maximum allowable installation depth at the current location is determined based on the building's main structural data. The target installation depth is determined based on the difference between the initial installation depth, the second-level deviation threshold, and the actual impact deviation value. The installation method is determined based on the comparison between the target installation depth and the maximum allowable installation depth. If the actual impact deviation value is greater than or equal to the third-level deviation threshold, the installation method is determined based on the difference between the actual impact deviation value and the third-level deviation threshold. The installation methods include chemical anchor bolt anchoring, pre-embedded component welding, and combined anchoring.

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