Building construction material replacement cost early warning method and system based on BIM

Abstract

The invention discloses a BIM-based building construction material replacement cost early warning method and system, and the method comprises the following operation steps: collecting the construction information of building construction, and constructing a BIM model through the collection of the construction information of building construction; component geometric features of building components are extracted from the BIM model, and a geometric feature constraint model is preliminarily constructed according to the component geometric features; analyzing the dynamic index of the building component according to the component geometric features, and updating the geometric feature constraint model to obtain a geometric feature model; collecting actual component data of a real building construction site, inputting the actual component data into the geometric feature model, and calculating the material replacement cost of the actual component data of the real building construction site; and early warning is performed according to the material replacement cost of the actual component data of the real building construction site.

Description

Technical Field

[0001] The present invention relates to the field of building cost loss, and in particular to a BIM-based building construction material replacement cost early warning method and system. Background Art

[0002] In modern construction projects, material management has always been one of the important factors affecting project cost control. During the construction process, due to design errors in drawings or construction operations, as well as improper material selection, the materials will be lost (that is, the loss of materials requires the replacement of new components, thus incurring costs). However, if the loss is not properly controlled, it will lead to serious overspending of the project budget and even affect the overall progress and quality of the project.

[0003] Therefore, how to accurately and in real time monitor material loss information in construction, and promptly detect and issue early warnings has become an urgent problem that needs to be solved in the construction industry.

[0004] Traditional construction material management methods usually rely on manual experience and traditional estimation methods, which often have certain errors and lack real-time and accuracy.

[0005] Especially in complex construction projects, manual estimates are unlikely to fully cover the material requirements and losses of all components. At the same time, they are also unable to effectively identify material waste caused by design changes, construction errors, etc. (i.e., material loss requires the replacement of new components, thereby incurring costs).

[0006] Therefore, how to improve the accuracy and real-time performance of material loss information management through modern technical means has become the focus of research in the industry.

[0007] The emergence of Building Information Modeling (BIM) technology provides new solutions for construction project management.

[0008] BIM technology can accurately reflect the design, construction and material requirements of buildings by creating three-dimensional digital models, providing a new way to manage various resources of construction projects.

[0009] Through the BIM model, project managers can not only visualize the building's geometry, size, location and other information, but also conduct a detailed analysis of each component in the construction process, including its material requirements, quantity, specifications, etc.

[0010] However, although BIM model technology can optimize the resource allocation and material management of construction projects to a certain extent, in actual applications, due to design changes, error corrections, and material loss information that may occur during the construction process, the original data of the BIM model often needs to be constantly adjusted and updated.

[0011] How to accurately monitor the loss of various materials in construction through BIM models and issue timely warnings is still a problem that needs to be solved urgently. Summary of the invention

[0012] The purpose of the present invention is to provide a BIM-based construction material replacement cost early warning method and system, which solves the above-mentioned technical problems pointed out in the prior art.

[0013] The present invention provides a BIM-based construction material replacement cost early warning method, comprising the following steps: Collecting construction information of the building construction, and constructing a BIM model through the collected construction information of the building construction; Extracting component geometric features of building components from the BIM model, and preliminarily constructing a geometric feature constraint model based on the component geometric features; analyzing dynamic indexes of building components based on the component geometric features, updating the geometric feature constraint model, and obtaining a geometric feature model; collecting actual component data of a real construction site and inputting it into the geometric feature model to calculate the material replacement cost of the actual component data of the real construction site; The material replacement cost is warned by using the actual component data of the real construction site.

[0014] Preferably, the geometric features of the building components are extracted from the BIM model, and a geometric feature constraint model is preliminarily constructed based on the geometric features of the components. The specific operation steps are as follows: Dividing the building components in the BIM model into component groups, and classifying the building components in each component group to obtain component types; Extracting component geometric features of different component types based on the component type; Geometric constraint parameters are set for the geometric features of the component, and the building components in the BIM model are constrained by the geometric constraint parameters to obtain a geometric feature constraint model.

[0015] Preferably, the geometric feature constraint model is updated to obtain a geometric feature model, and the specific operation steps are as follows: Analyzing the contact surfaces of the building components according to the geometric features of the components using a topological adjacency algorithm to determine the connection type of the connection points between the contact surfaces; Determine the connection position of each connection point between the contact surfaces; Record the connection position and connection type to obtain a connection storage table; Define the attributes of the component geometric features of all component types to form an attribute management set; Setting an attribute inheritance mapping relationship for the attribute management set; Determine whether the building components in each component group can transfer attributes according to the attribute inheritance mapping relationship; If not, create an attribute template for the building component, set an attribute inheritance mapping relationship for the same component type according to the attribute template, and re-determine whether the building components in each component group can transfer attributes according to the attribute inheritance mapping relationship; If yes, then determine that the building components in the component group are to be attributed to the determined building components, and at the same time, attribute transfer of the component group is to be performed on the building components of the same component type according to the attribute inheritance mapping relationship; Each building component is encoded according to the spatial position, component type and cost category of the building component, and an index hierarchy system is constructed according to the encoding to dynamically index the building components.

[0016] Preferably, the geometric feature constraint model is updated to obtain a geometric feature model, and the specific operation steps are as follows: The connection storage table is transferred with the attribute of the component family and the dynamic index of the building to update the geometric feature constraint model to obtain a new geometric feature model.

[0017] Preferably, the contact surfaces of the building components are analyzed according to the geometric features of the components using a topological adjacency algorithm to determine the connection types of the connection points between the contact surfaces. The specific operation steps are as follows: Calculating the number of connection points on the contact surfaces between the building components using a topological adjacency algorithm; Distinguishing between direct connection points and indirect connection points by the number of the connection points; Calculate the direct connection degree and the indirect connection degree through the direct connection points and the indirect connection points; The direct connection degree and the indirect connection degree are weightedly calculated to obtain the connection strength between the building components. The calculation formula is: ; In the formula, Expressed as the number of directly connected points; It is expressed as the number of indirect connection points; It is expressed as direct connection degree; It is expressed as the indirect connectivity; and They are respectively expressed as the weight of direct connectivity and the weight of indirect connectivity; It is expressed as the total number of connection points; Expressed as a constant; Preset a connection point bearing strength threshold p, and determine whether the connection strength between the building components is greater than the connection point bearing strength threshold p; If not, it is determined that there is no material loss information at the connection point between the contact surfaces of the building components; If so, it is determined that material loss information occurs at the connection point between the contact surfaces of the building components, and the connection type is determined for the connection point.

[0018] Preferably, the connection position of each connection point between the contact surfaces is determined, and the specific operation steps are as follows: The contact area of ​​the contact surface of the building component where the material loss information appears at the connection point is calculated, and the friction area between the building components is identified through the contact area, and the connection position of the connection point is determined for the friction area.

[0019] Preferably, the connection position and the connection type are recorded to obtain a connection storage table, and the specific operation steps are as follows: Determine whether there is a spatial relationship between two building components on the contact surface according to the friction area and the connection position; If not, it is determined that there is no spatial relationship between the two building components, and no material loss information appears between the two building components; If so, it is determined that there is a component spatial intersection relationship between the two building components, and material loss information occurs between the two building components; The spatial relationship determination includes: intersection detection determination, inclusion relationship determination, and adjacent relationship determination; The connection type and the connection positions of the two building components having a component spatial intersection relationship are recorded to obtain a connection storage table.

[0020] Preferably, the specific operation steps for determining whether the two building components have a component spatial intersection relationship are as follows: Determine a boundary range in a spatial position for each building component, calculate a minimum bounding box of each building component through the boundary range, and record spatial parameters of the minimum bounding box of the building component; The spatial parameters include the position and direction of the minimum bounding box in space; Perform axial projection on every two minimum bounding boxes to determine whether there is any overlap in the projections of the two minimum bounding boxes on any axis; If not, it is determined that the two minimum bounding boxes do not collide; If yes, it is determined that the two minimum bounding boxes collide, and the two building components corresponding to the two minimum bounding boxes are marked; Obtain the actual shape of the geometric features of each building component, perform geometric calculations based on the actual properties of each building component, and find key interference points; Determining whether there is contact interference between the two building components according to the key interference points; If not, it is determined that there is no contact interference problem between the two building components; If so, it is determined that there is contact interference between the two building components; All building component pairs that have collision and contact interference with two building components are listed, and the conflict types of the building component pairs are marked; a spatial conflict matrix is ​​constructed according to the conflict types.

[0021] Accordingly, the present invention also proposes a BIM-based building construction material replacement cost early warning system, comprising: a collection module; an identification module; an early warning module; A collection module is used to collect construction information of building construction, and to build a BIM model through the collected construction information of building construction; the main equipment of the above-mentioned collection module includes an image acquisition device, a handheld laser radar scanning device and an information data input terminal; the information data input terminal can assist in inputting part of the construction information into the BIM-based building construction material replacement cost early warning system; The identification module is used to extract the component geometric features of the building components from the BIM model, and preliminarily construct a geometric feature constraint model based on the component geometric features; analyze the dynamic index of the building components based on the component geometric features, update the geometric feature constraint model, and obtain a geometric feature model; identify the material replacement cost of the building components from the BIM model through the geometric feature model; The early warning module is used to issue an early warning warning based on the actual material replacement cost of the building components.

[0022] Compared with the prior art, the embodiments of the present invention have at least the following technical advantages: By analyzing the above-mentioned BIM-based construction material replacement cost early warning method and system provided by the present invention, it can be known that in specific applications, construction information of the construction is collected, and a three-dimensional digital model (i.e., BIM model) of the construction project is created through BIM software (such as Revit). The BIM model can accurately display the various components of the building and their relationships; Furthermore, the building components in the BIM model are classified to obtain different component types such as beams, columns, and walls; the component geometric features including the size, shape, and spatial position of the building components are extracted according to different component types; a geometric feature constraint model is constructed based on the combined features to describe the spatial relationship and component characteristics between components; the contact surface of the building components is analyzed according to the component geometric features using the topological adjacency algorithm, and then it is determined which parts are more tightly connected and which connections may have design defects or construction errors; the number of connection points between the building components is calculated through the contact surface, and the direct connection points and indirect connection points are distinguished, which can quantify the mutual dependence between the components, calculate the connection degree between the two, reveal which components have weaker connections and which connections are more solid, and help understand the structural stability of the building and the potential risks in the construction process; thereby, the entire connection strength of the building components is calculated, and then the connection strength of the entire building components is evaluated; and then the bearing strength between the building components is determined by setting the connection point bearing strength threshold p, so as to determine whether there is material loss information at the connection points between the building components, and then the cost of the connection position and connection type is calculated for the lost material; Furthermore, defining the attributes of the geometric features of component types can unify the basic data formats of different components in the BIM model, so that the data of various components can be consistently managed during the modeling, design and construction processes; setting attribute inheritance mapping relationships can simplify the attribute transfer process in complex component relationships, ensuring that the inheritance of attributes in the hierarchical structure is systematic and automated; by judging whether certain components have material loss information, the attribute transfer mechanism can be started in a targeted manner; if a certain type of component has material loss information, the attributes of these losses (such as dimensional changes, material properties, etc.) can be automatically transferred to related subsequent components or corresponding subsystems, thereby ensuring that the loss information will not be lost during the component replacement or repair process; for example, if a certain part of the beam has material loss information, the loss information can be automatically transferred to the ... Material loss information is partly caused by construction problems, and its loss information can be transmitted to the subsequent columns or walls connected to the beam, which is crucial for later quality control and material planning; and an index hierarchy system is constructed according to the spatial position, component type and cost category of the building components. By constructing an index hierarchy system according to the spatial position, component type and cost category of the components, all components in the building can be managed in an orderly manner; this index hierarchy based on spatial position and functional type can help dynamically adjust the location, type or cost evaluation of components at different stages of the building life cycle; dynamic indexing of building components, organizing and managing component data through a dynamic index system, can support rapid query, update and adjustment of building components; Furthermore, when the properties of the connection storage table and the component family are transferred and the dynamic index is updated, the geometric feature constraint model will be automatically updated according to the new component properties; in this way, the size change or material adjustment of a component can be automatically reflected in the geometric feature constraint model, ensuring that the new geometric feature model is consistent with the actual situation of the building; thus, the loss cost of a building material to be replaced or consumed can be calculated more intuitively, thereby issuing an early warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a flow chart of a BIM-based construction material replacement cost early warning method according to Embodiment 1; Figure 2 A flowchart of creating a geometric feature model for a BIM-based construction material replacement cost early warning method according to Embodiment 1; Figure 3 A flow chart for recording the loss of building component connection points of a BIM-based construction material replacement cost early warning method according to Embodiment 1; Figure 4 A schematic diagram of connection points of contact surfaces of building components of a BIM-based construction material replacement cost early warning method according to Embodiment 1; Figure 5 A BIM-based construction material replacement cost early warning method for implementing the first embodiment Figure 4 Schematic diagram of building components decomposition intuitive connection point diagram; Figure 6 A flowchart of a BIM-based construction material replacement cost early warning method for determining the loss of corresponding building components according to connection points in Example 1; Figure 7 This is a flow chart of a BIM-based construction material replacement cost early warning system according to Example 2; Label: collection module 10; identification module 20; early warning module 30. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0025] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0026] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0027] Embodiment 1 like Figure 1 As shown, the present invention provides a BIM-based construction material replacement cost early warning method, comprising the following steps:

[0028] S1: Collecting construction information of a building, and constructing a BIM model by using the collected construction information of the building; It should be noted that the construction information of the building is collected and a three-dimensional digital model of the building project is created through BIM software (such as Revit); the BIM model contains the geometry, size, position and other related properties of all components of the building (such as walls, columns, beams, doors, windows, floors, etc.); and can also accurately display the various components of the building and their relationships; the construction information of the above-mentioned building construction includes the visible light image information of the building and the point cloud information scanned by the handheld laser radar; S2: extracting the component geometric features of the building components from the BIM model, and preliminarily constructing a geometric feature constraint model based on the component geometric features; analyzing the dynamic index of the building components based on the component geometric features, updating the geometric feature constraint model, and obtaining a geometric feature model; collecting actual component data of the real construction site (that is, the actual component data of the real construction site is from the same source as the construction information of the building collected in step S1, both of which are obtained through visible light image information of the building and point cloud information scanned by a handheld laser radar) and inputting it into the geometric feature model to calculate the material replacement cost of the actual component data of the real construction site; It should be noted that each building component (such as walls, doors, windows, columns, etc.) has its own specific geometric characteristics (such as shape, size, volume, etc.); extracting these characteristics through the BIM model can provide a technical basis for the subsequent calculation of replacement material costs; using these component geometric characteristics, a geometric feature constraint model is initially constructed to describe the spatial relationship and component characteristics between components; this geometric feature constraint model is helpful for the subsequent analysis of the relationship between components and the determination of the precise material requirements; that is, a geometric feature constraint model is constructed based on the above BIM model, and when using it, you only need to load the geometric feature constraint model module to call it.

[0029] By analyzing the geometric features of the components, a dynamic index is established and the geometric constraint model is updated in real time; this can reflect any changes that may occur in the design process of the building and adjust the geometric feature model in time to ensure its accuracy; Finally, the updated geometric feature model can accurately identify the material loss information of each component. For example, some components may cause unnecessary material waste due to design changes or construction errors. The BIM system can identify these problems through model analysis. After obtaining the new geometric feature model, the actual component data of the real construction site is collected, and the actual component data of the real construction site to be replaced is input into the geometric feature model to calculate the replacement material cost; S3: issuing an early warning of the material replacement cost based on the actual component data of the real construction site.

[0030] It should be noted that by analyzing the material requirements of components in the BIM model, it is possible to discover material waste caused by design errors or component wear. For example, a component may require additional materials due to dimensional calculation errors, or cause unnecessary cutting and waste due to construction errors. The BIM model can detect these problems at an early stage, and the cost of these wasted building components can be statistically analyzed through the geometric feature model. When the material replacement cost of the actual component data of the real construction site reaches a certain threshold, the system will automatically issue a warning to prompt project managers to pay attention to possible cost overruns and make adjustments. Specifically, Figure 2 As shown, in step S2, the geometric features of the building components are extracted from the BIM model, and a geometric feature constraint model is preliminarily constructed according to the geometric features of the components; the dynamic index of the building components is analyzed according to the geometric features of the components, and the geometric feature constraint model is updated to obtain a geometric feature model. The specific operation steps are as follows: S21: Divide the building components in the BIM model into component groups, and classify the building components in each component group to obtain component types; Extracting component geometric features of different component types based on the component type; Setting geometric constraint parameters for the geometric features of the component, constraining the building components in the BIM model through the geometric constraint parameters, and obtaining a geometric feature constraint model; It should be noted that by classifying the building components in the BIM model, different component types such as beams, columns, and walls can be obtained; the geometric feature data of these component types can be extracted, such as: the size (such as length, width, height, etc.), shape (such as rectangle, circle, I-shape, etc.) and spatial position (such as coordinates, direction) of the building components; for complex shapes (such as curved beams or irregular walls), geometric modeling algorithms (such as CAD geometric algorithms) are used to extract specific geometric information, and the component geometric features of different component types are obtained (that is, the component geometric features include information data such as the size, shape, and spatial position of the building components); And further set geometric constraints, such as: define size change range constraints (i.e. set size change limits for components, such as the span-to-section height ratio of a beam must not be greater than 1 / 15), position constraints (i.e. set relative position constraints and absolute position constraints between components to ensure the correct arrangement of components in space; for example, ensure that the connection between beams and columns meets design requirements), shape deformation rules (i.e. define rules for component shape changes (such as changes in the cross-sectional form of beams, changes in the thickness of walls, etc.); specify specific deformation rules for each component type according to design requirements); Constrain the geometric feature data of the building components in the BIM model according to the set geometric constraint conditions, so as to obtain a geometric feature constraint model; S22: Analyzing the contact surfaces of the building components according to the geometric features of the components using a topological adjacency relationship algorithm (or topological relationship), and determining the connection types of the connection points between the contact surfaces; Determine the connection position of each connection point between the contact surfaces; Record the connection position and connection type to obtain a connection storage table; It should be noted that the contact surface between components is identified using the topological adjacency algorithm; the contact surface refers to the contact area between two components in space, which usually determines the physical connection and force transmission path between the components; the connection points between the contact surfaces are judged to have their connection type, such as full contact, partial contact, point contact, line contact, etc.; different connection types will affect the distribution and transmission of force, thereby determining the stability and load capacity of the component; if there is a problem with the location of the contact point or the connection type (such as incomplete connection, partial contact or loose connection, etc.), it may cause excessive wear or damage to the structure under load; these damages will result in the need to replace the material of the damaged part. In order to repair the damaged connection point or contact surface, it may be necessary to replace part of the material of the component, thereby increasing the cost; Record the detailed location of each contact point to ensure that each contact point in the space has accurate location data; S23: define the attributes of the component geometric features of all component types to form an attribute management set; Setting an attribute inheritance mapping relationship for the attribute management set; Determine whether the building components in each component group can transfer attributes according to the attribute inheritance mapping relationship; If not, create an attribute template for the building component, set an attribute inheritance mapping relationship for the same component type according to the attribute template, and re-judge whether the building components in each component group can transfer attributes according to the attribute inheritance mapping relationship (that is, the judgment condition is whether all components in the component group belong to the same component type or the same family (component family) and can share attributes, that is, attribute transfer); If yes, then determine that the building components in the component group are to be attributed to the determined building components, and at the same time, attribute transfer of the component group is to be performed on the building components of the same component type according to the attribute inheritance mapping relationship; It should be noted that all building component types (such as walls, doors, windows, columns, etc.) are defined with their geometric features and other related attributes (such as material, size, function, etc.); these attribute definitions are summarized into a "attribute management set", which is crucial for subsequent management, design and maintenance; After defining the properties of each component type, you need to set the property inheritance mapping relationship; the property inheritance mapping relationship determines how to transfer these properties from one component to other similar or same type components; for example, if a wall component sets a certain property (such as material), then other wall components in the wall family can automatically inherit these properties; setting the property inheritance mapping relationship can simplify subsequent design and modification work; if a property (such as wall material, elevation, etc.) changes, you only need to modify it once on the management set or a specific component, and the inheritance rule can automatically propagate this change to other components of the same type; each component in a construction project (such as walls, floors, doors and windows, etc.) usually has cost attributes associated with it, such as material unit price, construction cost, etc.; by setting the property inheritance mapping relationship, when the properties of a component (such as wall material or elevation) change, the related cost attributes can also be automatically updated synchronously; this automated property update can ensure that the cost information of all components remains consistent during the project progress. For example, when the wall material is changed from ordinary bricks to high-end ceramic tiles, the relevant costs will be automatically updated with the material changes, avoiding the underestimation or overestimation of costs caused by missing updates, which in turn affects the subsequent cost warnings; design changes (such as changing building materials, changing construction methods, adjusting component sizes, etc.) often directly affect the cost budget of the project. Through the attribute inheritance mapping relationship, design changes will not only be updated to specific components in real time, but will also be automatically transmitted to all related components; For each component group (e.g., floor, building module, etc.), the system needs to determine whether all components in the component group meet the inheritance rules and can smoothly transfer properties; this determination involves detecting whether the components in the current component group meet the inheritance conditions (i.e., the judgment condition is whether all components in the component group belong to the same component type or the same family (component family) and can share properties, that is, property transfer); If it is found during the judgment that some components cannot be transferred according to the predetermined attribute inheritance mapping relationship (possibly due to component type mismatch or different component families, etc.), it is necessary to create an attribute template for the component type, which contains all relevant attributes and inheritance rules; then, reset the attribute inheritance mapping relationship of the component type according to this template, and then judge the attribute transfer again; this method ensures that no matter what kind of components are encountered, as long as they have attribute templates defined in the model, the inheritance rules can be reset according to the template, ensuring that these components meet the standardization requirements when transferring attributes, thereby avoiding omissions or errors (i.e., assuming that the size of a standard window is W , the material is aluminum alloy, and the window opening method is sliding; this information is passed to all standard windows through the family template in the BIM system; however, due to temporary requirements, the standard windows are replaced with special windows. Due to design requirements, the special windows use a different family (such as a more complex window frame structure), which makes it impossible to inherit the size and material information of the standard windows; therefore, a property template is created for the special windows, which stipulates that the size inherits the W of the standard windows, the material inherits the aluminum alloy material of the standard windows, and the window opening method inherits the sliding method of the standard windows; after setting these rules, the properties of the special window type will be automatically inherited according to this template, thus avoiding the failure of property transfer); If the component is determined to be in compliance with the attribute inheritance mapping relationship, the component's attributes will be transferred according to the rules; specifically, if a component (such as a wall) is used as a reference component, its attributes will be transferred to other components of the same component type, or even other components in the entire component family; for example, all walls in a component family can inherit the same material attributes, thickness, etc.; through attribute transfer, the consistency of components of the same type is ensured to avoid mismatches and unnecessary material waste caused by different attributes, thereby increasing costs (that is, in architectural design, all wall columns (i.e. building components) are often designed with the same size, bearing capacity, etc. as a component type. If a design problem occurs in one of the wall columns, all wall columns may also have problems. At this time, an attribute inheritance mapping relationship will appear, causing all wall columns of the same type of components to be replaced, thereby causing component loss cost problems); By ensuring the transfer of properties, resource utilization can be improved, avoiding waste caused by modifying the design or reselecting materials; S24: encoding each building component according to the spatial position, component type and cost category of the building component, constructing an index hierarchy system according to the encoding, and dynamically indexing the building component; It should be noted that the explanation of step S21 has explained that the geometric features of the component include the size, spatial position, and shape of the component; at the same time, the cost categories of different components are calculated by component type (that is, the cost of each category of components may be different, and there are as many cost categories as there are component types); therefore, the index can be designed according to the spatial hierarchy of the building, such as the floor and area, through the spatial position, component type, and cost category, and the coding can be further divided according to the material and cost category of the component. For example, different codes can be set for "high-cost components" and "low-cost components", making it more convenient to track the cost later; a dynamic index of building components with an index hierarchy system is constructed through coding. When the attributes of the component (such as cost, material, etc.) change, the system will automatically update the index. For example, if the cost of a component changes, the system will immediately update the index by incremental update without rebuilding the entire index structure; At the same time, the loss of the component material of the contact point in step S22 and the component material in step S23 is retrieved through dynamic indexing, so as to replace and accumulate the cost consumables, providing convenience; S25: updating the geometric feature constraint model by transferring the attribute of the connection storage table and the component family and the dynamic index of the building to obtain a new geometric feature model; It should be noted that the connection storage table records the material loss information of the connection points between building components. At the same time, the constructed attribute transfer can replace the material loss information of the connection points of this type with the same family (that is, although the component type describes the materials such as walls and columns, the connection between these walls and columns also requires connection points, such as the loss of cement, steel bars and other materials) to ensure the safety of the building, and the same family attribute transfer calculation cost budget can be performed for the wall, column and other materials of the component type; and the loss material that needs to be replaced can be retrieved through dynamic indexing (that is, assuming that in a construction project, the material of a column family is changed from reinforced concrete soil into steel bars; update all connection points related to the column in the connection storage table (such as the connection between the column and the wall), and transfer attributes according to the loss information of the new material steel bars; the system retrieves all affected connection points (such as the connection points between the column and the wall) through dynamic indexing, and updates their loss materials (such as steel bar loss); based on the updated loss information, recalculate the connection relationship between the column and the wall, and may adjust the geometric constraints of the connection points, and recalculate the load and material distribution; finally generate an updated geometric feature model to ensure that the geometric constraints and material losses of all components and connection points meet the new requirements and the safety of the building is guaranteed); The specific update instructions are as follows: obtain the component geometric features (such as size, shape, material, position, etc.) of the component from the connection storage table of the component family, and pass these attributes together with the geometric constraint information (such as distance, angle, parallelism, perpendicularity, etc.) to the geometric feature constraint model; update the dynamic index of the building so that the constraint information of each building component is correctly associated with its component geometric features to ensure that it can be reflected in the geometric feature constraint model in real time; according to the transmitted constraints, use geometric solution algorithms (such as constraint solution based on graph theory, optimization algorithm, etc.) to solve the uncertainty and correlation in the constraint system, and then generate specific geometric shapes; this step converts the abstract constraint model into a specific geometric shape by solving all geometric constraints (such as distance, angle, parallelism, perpendicularity, etc.), and establishes a model that conforms to the actual The geometric features required by the actual design are obtained; a new geometric feature model is obtained according to the updated constraint conditions and calculation results; the new geometric feature model not only includes the geometric shape of the building component, but also may include other function-related features (such as material, strength, etc. In the expansion in step S22, the connection strength of the connection point between the contact surfaces of the building components is used to determine whether the damaged component needs to be replaced. At the same time, the bearing capacity of the connection strength of the connection point may cause problems to the two building components on the contact surface (that is, due to the poor bearing capacity of the connection point, the contact surface building component may be damaged, so it also indirectly reflects the material and strength of the building component, and also reflects the material and strength of the connection point (that is, hinges, cement, etc.)), and these features have been affected by the update and optimization of the constraint model; In the design and construction process of a building, it is crucial to ensure the connection safety between building components and the rational use of materials. In order to optimize the stability and material consumption of the building structure, the contact surfaces and connection points between the components must be accurately analyzed, so as to accurately identify the possible material loss areas and take effective prevention and repair measures in time. For details, see steps S221 to S223; Specifically, Figure 3 As shown, in step S22, the contact surface of the building component is analyzed according to the geometric features of the component using a topological adjacency algorithm to determine the connection type of the connection points between the contact surfaces; the connection position of each connection point between the contact surfaces is determined; the connection position and the connection type are recorded to obtain a connection storage table. The specific operation steps are as follows: S221: Calculating the number of connection points on the contact surfaces between the building components using a topological adjacency algorithm; Distinguishing between direct connection points and indirect connection points by the number of the connection points; Calculate the direct connection degree and the indirect connection degree through the direct connection points and the indirect connection points; The direct connection degree and the indirect connection degree are weightedly calculated to obtain the connection strength between the building components. The calculation formula is: ; In the formula, Expressed as the number of directly connected points; It is expressed as the number of indirect connection points; It is expressed as direct connection degree; It is expressed as the indirect connectivity; and They are respectively expressed as the weight of direct connectivity and the weight of indirect connectivity; It is expressed as the total number of connection points; Expressed as a constant; Preset a connection point bearing strength threshold p, and determine whether the connection strength between the building components is greater than the connection point bearing strength threshold p; If not, it is determined that there is no material loss information at the connection point between the contact surfaces of the building components; If so, it is determined that the connection point between the contact surfaces of the building components has material loss information (that is, the material of the contact surface connection point is bad (i.e. hinge, cement, steel bar, etc.), such as rust, cracks and other bad defect information, so the connection strength of the connection point is poor due to these bad defect information, which is lower than the connection point bearing strength threshold p), and the connection type of the connection point is determined (that is, the determined connection type is the same as the example in the explanation of the above step S23. When a wall column component has a problem, the components of the same type of connection (i.e. hinge, etc.) need to be replaced in the same way); It should be noted that each component has different connection points in the structure, and the connection relationship between each node and the component is defined; for each component, the number of connection points with it is counted; through the connection relationship between each node and the component, the direct connection point is found (i.e., a direct connection point refers to a direct physical connection between two nodes (i.e., building components), such as Figure 4 As shown, usually no other intermediary nodes or components are required; that is, the connection between the two nodes is "direct" without any intermediate links) and indirect connection points (i.e., indirect connection points refer to the connection between the two nodes being achieved through other intermediary nodes or components; that is, although the two nodes have no direct physical connection, they are connected to each other through other components). For details, please see Figure 4 Differentiation of building components such as Figure 5As shown; direct connection points and indirect connection points are used to calculate the direct connection degree (i.e., measured by graphical tools or by calculating the number of direct connections between nodes (i.e., building components)) and the indirect connection degree; The connection strength between the entire building components is calculated by weighting the direct connection degree and the indirect connection degree (that is, there is not necessarily only one connection point between the building components, and there may be multiple connection points connected at the same time, so all the connection points need to be weighted to calculate, so as to obtain the connection strength between the building components); then the connection point bearing strength threshold p is set according to the connection strength to determine whether the connection strength between the building components exceeds the predetermined bearing strength, so as to determine whether the loss of the connection point component material needs to be replaced, and the connection type of the lost component material is recorded (that is, the connection method is recorded, and the attribute of the component type is transferred in the subsequent step S23 to replace the component material of the entire connection type); S222: calculating the contact area of ​​the contact surface of the building component where the material loss information appears at the connection point, identifying the friction area between the building components through the contact area, and determining the connection position of the connection point for the friction area; Determine whether a spatial relationship occurs between two building components on the contact surface according to the friction area and the connection position (i.e., the determination of the spatial relationship is determined based on conditions such as the collision volume or overlapping area of ​​the building components in the friction area); If not, it is determined that there is no spatial relationship between the two building components, and it is also determined that there is no material loss information between the two building components; If so, it is determined that there is a component spatial intersection relationship between the two building components, and it is determined that material loss information occurs between the two building components; The spatial relationship determination includes: intersection detection determination (i.e., overlap may lead to space waste, structural conflict or other safety hazards; for example, the intersection of two beams may lead to unstable structural strength, or the overlap of pipelines and structural components may affect the normal installation of pipelines), inclusion relationship determination (i.e., confirming whether a component is completely contained in another component, or whether it is subordinate to or dependent on another component; for example, whether the beam is completely supported on the column, or whether the floor panel is completely contained in the wall), adjacent relationship determination (i.e., during construction, if the components are too close to each other, it may interfere with the construction progress or increase the difficulty of construction; for example, some pipelines may be affected by other components (such as walls, beams, etc.) during installation, resulting in the need to re-plan the construction plan); It should be noted that the contact points of building components are analyzed and their contact areas are calculated; the size of the contact area can help assess the risk of friction and material loss information; Through the contact area, the friction area between the two components is identified and the connection position of the connection point is determined; the size, shape and distribution of the friction area may have an impact on the long-term use of the component, especially under high load conditions, friction may cause material wear or structural weakening; Based on the friction area and connection position, determine whether the two components have a spatial intersection relationship. If the two components interfere or intersect in space, it indicates that they have improper contact or structural conflict, which may lead to additional material loss information; If there is a spatial relationship conflict or friction area overlap between two components, it is determined that these components have material loss information, otherwise it is determined that there is no loss; S223: Recording the connection type and the connection positions of the two building components having a component spatial intersection relationship, to obtain a connection storage table; It should be noted that the connection type records the loss of the material connected between two building components, that is, the loss of the component at the connection point; and the two building components at the connection position where the component space intersects may cause the two building components to have problems such as load-bearing, resulting in the loss of the two building components. Therefore, recording the position of the connection point can make it more convenient to retrieve the loss in step S24, thereby providing a convenient cost calculation for the attribute transfer of the component type. In the process of building design and construction, ensuring the reasonable layout and precise connection between components is the key to ensuring structural stability and normal function. The spatial relationship between components, especially collision and contact interference, often directly affects the smooth progress of construction, the rational use of materials and the subsequent maintenance costs; therefore, how to efficiently and accurately identify and deal with possible spatial conflicts between components has become an issue that cannot be ignored in the design and construction stages; Specifically, Figure 6 As shown, in step S222, it is determined that there is a component spatial intersection relationship between the two building components, and the specific operation steps are as follows: S2221: Determine the boundary range of each building component in the spatial position (i.e., describe these boundaries by the minimum circumscribed rectangle (3D bounding box) of the component), calculate the minimum bounding box of each building component (i.e., the smallest rectangular cube that can completely surround the component) by the boundary range, and record the spatial parameters of the minimum bounding box of the building component; The spatial parameters include the position and direction of the minimum bounding box in space (i.e., the position in space is the spatial position of the minimum bounding box, which is usually obtained by calculating the minimum circumscribed rectangle or cuboid of the component; while the spatial position of the building component describes the center point, rotation angle, size and other information of the component relative to a certain coordinate system (usually a global coordinate system or a local coordinate system), which are different); Perform axial projection on every two minimum bounding boxes (i.e., every two building components, i.e., two building components on the contact surface) to determine whether there is any overlap in the projections of the two minimum bounding boxes on any axis; If not, it is determined that the two minimum bounding boxes do not collide; If yes, it is determined that the two minimum bounding boxes collide, and the two building components corresponding to the two minimum bounding boxes are marked; It should be noted that the minimum bounding box (i.e., the smallest rectangular cube that can completely enclose the shape of each component in three-dimensional space) is constructed to determine whether there is a collision between components. This method uses axial projection technology to perform preliminary collision detection on each pair of components and quickly identify which components may have spatial collisions. By calculating the minimum circumscribed rectangle (3D bounding box) of the building components, a spatial boundary can be defined for each component, which helps to determine whether the components have spatial collisions. The minimum bounding boxes of every two components are axially projected to check whether there is overlap. If there is overlap, a collision may occur. This step provides a basis for subsequent interference analysis and spatial conflict identification. By quickly determining which components may collide, the computational complexity is reduced, preparing for accurate collision interference analysis. If collisions between components are found during construction, it is usually necessary to adjust the design or construction plan. Such adjustments may lead to material waste, extended construction period, or even the need for rework, which will increase additional construction costs; S2222: Obtain the actual shape of the component geometric features of each building component, perform geometric calculations based on the actual properties of each building component, and find key interference points; Determine whether there is contact interference between the two building components according to the key interference points (i.e., whether the two components penetrate into each other's space, resulting in contact interference but not actual penetration; or whether the distance is close enough to affect the function or structure but no actual penetration occurs); If not, it is determined that there is no contact interference problem between the two building components; If yes, it is determined that there is contact interference between the two building components (i.e., if there is contact interference, it means that there are problems in the layout and construction of the two building components, and they need to be replaced or rebuilt, which will also cause budget costs for materials); It should be noted that by obtaining the actual geometric shape of each component and performing geometric calculations, we can find out whether there is actual contact interference between the components. Contact interference means that although the components do not completely penetrate each other's space, their surfaces are very close, which may affect the integrity of the construction or design. According to the actual geometric characteristics of each component (such as curved surfaces, edges, etc.), key interference points are identified. These points may be where the surfaces of the components are closest or collide with each other. If two components are very close in space but not completely interspersed, this may still affect the stability or function of the structure. Therefore, this interference is regarded as contact interference and needs to be resolved in the design or construction stage. Through precise geometric analysis, it is determined which components have real contact interference, and potential construction problems are discovered in time to avoid subsequent rework or design modifications. Even if there is no complete interpenetration, contact interference may affect the function or performance of the component, leading to later repairs or modifications, further increasing maintenance costs; S2223: List all pairs of building components (i.e., two building components) that have collision and contact interference between two building components, mark the conflict types of the building component pairs (i.e., collision, contact interference); construct a spatial conflict matrix (i.e., component spatial intersection relationship) based on the conflict types; It should be noted that the collision and contact interference of all building components are comprehensively recorded and managed to establish a conflict matrix; the spatial conflict matrix records the conflict type and degree of conflict between each pair of components, and forms a spatial conflict matrix by recording the collision or contact interference type of each pair of components; each element in the spatial conflict matrix represents the conflict state between two building components, thereby obtaining the intersection relationship between the two building components; Embodiment 2 like Figure 7 As shown, the present invention also provides a BIM-based construction material replacement cost early warning system, comprising: a collection module 10; an identification module 20; an early warning module 30; The acquisition module 10 is used to acquire the construction information of the building construction, and to build the BIM model through the acquired construction information of the building construction; the main equipment of the acquisition module 10 includes an image acquisition device, a handheld laser radar scanning device and an information data input terminal; the information data input terminal can assist in inputting part of the construction information into the BIM-based building construction material replacement cost early warning system; The identification module 20 is used to extract the component geometric features of the building components from the BIM model, and preliminarily construct a geometric feature constraint model based on the component geometric features; analyze the dynamic index of the building components based on the component geometric features, update the geometric feature constraint model, and obtain a geometric feature model; identify the material replacement cost of the building components from the BIM model through the geometric feature model; The early warning module 30 is used to issue an early warning warning based on the actual material replacement cost of the building component.

[0031] In summary, the BIM-based construction material replacement cost early warning method and system proposed in the present invention can be seen that by collecting the construction information of the building construction and creating a three-dimensional digital model (i.e., BIM model) of the building project through BIM software (such as Revit), the BIM model can accurately display the various components of the building and their relationships; Furthermore, the building components in the BIM model are classified to obtain different component types such as beams, columns, and walls; the component geometric features including the size, shape, and spatial position of the building components are extracted according to different component types; a geometric feature constraint model is constructed based on the combined features to describe the spatial relationship and component characteristics between components; the contact surface of the building components is analyzed according to the component geometric features using the topological adjacency algorithm, and then it is determined which parts are more tightly connected and which connections may have design defects or construction errors; the number of connection points between the building components is calculated through the contact surface, and the direct connection points and indirect connection points are distinguished, which can quantify the mutual dependence between the components, calculate the connection degree between the two, reveal which components have weaker connections and which connections are more solid, and help understand the structural stability of the building and the potential risks in the construction process; thereby, the entire connection strength of the building components is calculated, and then the connection strength of the entire building components is evaluated; and then the bearing strength between the building components is determined by setting the connection point bearing strength threshold p, so as to determine whether there is material loss information at the connection points between the building components, and then the cost of the connection position and connection type is calculated for the lost material; Furthermore, defining the attributes of the geometric features of the component types can unify the basic data formats of different components in the BIM model, so that the data of various components can be managed consistently during the modeling, design and construction processes; setting the attribute inheritance mapping relationship can simplify the attribute transfer process in complex component relationships, ensuring that the inheritance of attributes in the hierarchical structure is systematic and automated; by judging whether certain components have material loss information, the attribute transfer mechanism can be started in a targeted manner; if a certain type of component has material loss information, the attributes of these losses (such as dimensional changes, material properties, etc.) can be automatically transferred to the relevant subsequent components or corresponding subsystems, thereby ensuring that the loss information will not be lost during the component replacement or repair process; For example, if a part of a beam causes material loss due to construction problems, the loss information can be transmitted to the subsequent columns or walls connected to the beam, which is crucial for subsequent quality control and material planning; and an index hierarchy system is constructed according to the spatial position, component type and cost category of the building components. By constructing an index hierarchy system according to the spatial position, component type and cost category of the components, all components in the building can be managed in an orderly manner; this index hierarchy based on spatial position and functional type can help dynamically adjust the location, type or cost assessment of components at different stages of the building life cycle; dynamically indexing building components, organizing and managing component data through a dynamic index system, can support rapid query, update and adjustment of building components; Furthermore, when the properties of the connection storage table and the component family are transferred and the dynamic index is updated, the geometric feature constraint model will be automatically updated according to the new component properties; in this way, the size change or material adjustment of a component can be automatically reflected in the geometric feature constraint model, ensuring that the new geometric feature model is consistent with the actual situation of the building; thus, the loss cost of a building material to be replaced or consumed can be calculated more intuitively, thereby issuing an early warning.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. A person skilled in the art may modify the technical solutions described in the above embodiments, or replace part or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A BIM-based construction material replacement cost early warning method, characterized in that: The steps include: Collecting construction information of the building construction, and constructing a BIM model through the collected construction information of the building construction; Extracting component geometric features of building components from the BIM model, and preliminarily constructing a geometric feature constraint model based on the component geometric features; Analyze the dynamic index of the building components according to the geometric characteristics of the components, update the geometric characteristic constraint model, and obtain the geometric characteristic model; Collecting actual component data of a real construction site and inputting it into the geometric feature model to calculate the material replacement cost of the actual component data of the real construction site; Early warning of material replacement costs based on actual component data from real construction sites.

2. According to claim 1, a BIM-based construction material replacement cost early warning method is characterized in that: The geometric features of the building components are extracted from the BIM model, and a geometric feature constraint model is preliminarily constructed based on the geometric features of the components. The specific operation steps are as follows: Dividing the building components in the BIM model into component groups, and classifying the building components in each component group to obtain component types; Extracting component geometric features of different component types based on the component type; Geometric constraint parameters are set for the geometric features of the component, and the building components in the BIM model are constrained by the geometric constraint parameters to obtain a geometric feature constraint model.

3. According to claim 2, a BIM-based construction material replacement cost early warning method is characterized in that: Update the geometric feature constraint model to obtain the geometric feature model. The specific steps are as follows: Analyzing the contact surfaces of the building components according to the geometric features of the components using a topological adjacency algorithm to determine the connection type of the connection points between the contact surfaces; Determine the connection position of each connection point between the contact surfaces; Record the connection position and connection type to obtain a connection storage table; Define the attributes of the component geometric features of all component types to form an attribute management set; Setting an attribute inheritance mapping relationship for the attribute management set; Determine whether the building components in each component group can transfer attributes according to the attribute inheritance mapping relationship; If not, then create an attribute template for the building component, perform attribute inheritance mapping relationship for the same component type according to the attribute template, and re-judge whether the building components in each component group can perform attribute transfer according to the attribute inheritance mapping relationship; If yes, then determine that the building components in the component group are to be attributed to the determined building components, and at the same time, attribute transfer of the component group is to be performed on the building components of the same component type according to the attribute inheritance mapping relationship; Each building component is encoded according to the spatial position, component type and cost category of the building component, and an index hierarchy system is constructed according to the encoding to dynamically index the building components.

4. According to claim 3, a BIM-based construction material replacement cost early warning method is characterized in that: Update the geometric feature constraint model to obtain the geometric feature model. The specific steps are as follows: The connection storage table is transferred with the attribute of the component family and the dynamic index of the building to update the geometric feature constraint model to obtain a new geometric feature model.

5. According to claim 4, a BIM-based construction material replacement cost early warning method is characterized in that: The contact surface of the building components is analyzed according to the geometric features of the components using a topological adjacency algorithm to determine the connection type of the connection points between the contact surfaces. The specific operation steps are as follows: Calculating the number of connection points on the contact surfaces between the building components using a topological adjacency algorithm; Distinguishing between direct connection points and indirect connection points by the number of the connection points; Calculate the direct connection degree and the indirect connection degree through the direct connection points and the indirect connection points; The direct connection degree and the indirect connection degree are weightedly calculated to obtain the connection strength between the building components. The calculation formula is: ; In the formula, Expressed as the number of directly connected points; It is expressed as the number of indirect connection points; It is expressed as direct connection degree; It is expressed as the indirect connectivity; and They are respectively expressed as the weight of direct connectivity and the weight of indirect connectivity; It is expressed as the total number of connection points; Expressed as a constant; Preset a connection point bearing strength threshold p, and determine whether the connection strength between the building components is greater than the connection point bearing strength threshold p; If not, it is determined that there is no material loss information at the connection point between the contact surfaces of the building components; If so, it is determined that material loss information occurs at the connection point between the contact surfaces of the building components, and the connection type is determined for the connection point.

6. According to claim 5, a BIM-based construction material replacement cost early warning method is characterized in that: Determine the connection position of the connection point between each contact surface. The specific steps are as follows: The contact area of ​​the contact surface of the building component with material loss information at the connection point is calculated, and the friction area between the building components is identified through the contact area, and the connection position of the connection point is determined in the friction area.

7. According to claim 6, a BIM-based construction material replacement cost early warning method is characterized in that: The connection position and connection type are recorded to obtain a connection storage table. The specific operation steps are as follows: Determine whether there is a spatial relationship between two building components on the contact surface according to the friction area and the connection position; If not, it is determined that there is no spatial relationship between the two building components, and no material loss information appears between the two building components; If so, it is determined that there is a component spatial intersection relationship between the two building components, and material loss information occurs between the two building components; The spatial relationship determination includes: intersection detection determination, inclusion relationship determination, and adjacent relationship determination; The connection type and the connection positions of the two building components having a component spatial intersection relationship are recorded to obtain a connection storage table.

8. The BIM-based construction material replacement cost early warning method according to claim 7 is characterized in that: Determine whether the two building components have a component space intersection relationship, and the specific operation steps are as follows: Determine a boundary range in a spatial position for each building component, calculate a minimum bounding box of each building component through the boundary range, and record spatial parameters of the minimum bounding box of the building component; The spatial parameters include the position and direction of the minimum bounding box in space; Perform axial projection on every two minimum bounding boxes to determine whether there is any overlap in the projections of the two minimum bounding boxes on any axis; If not, it is determined that the two minimum bounding boxes do not collide; If yes, it is determined that the two minimum bounding boxes collide, and the two building components corresponding to the two minimum bounding boxes are marked; Obtain the actual shape of the geometric features of each building component, perform geometric calculations based on the actual properties of each building component, and find key interference points; Determining whether there is contact interference between the two building components according to the key interference points; If not, it is determined that there is no contact interference problem between the two building components; If so, it is determined that there is contact interference between the two building components; List all pairs of building components that have collision and contact interference with two building components, and mark the conflict types of the building component pairs; Construct a spatial conflict matrix based on conflict types.

9. A BIM-based early warning system for replacement costs of building construction materials, characterized in that: include: Acquisition module; Identify the module; Early warning module; A collection module, used for collecting construction information of building construction, and constructing a BIM model by collecting the construction information of building construction; The main equipment of the acquisition module includes an image acquisition device, a handheld laser radar scanning device and an information data input terminal; the information data input terminal can assist in inputting part of the construction information into the BIM-based building construction material replacement cost early warning system; An identification module is used to extract component geometric features of building components from the BIM model and preliminarily construct a geometric feature constraint model based on the component geometric features; Analyze the dynamic index of the building components according to the geometric characteristics of the components, update the geometric characteristic constraint model, and obtain the geometric characteristic model; Identifying the material replacement cost of building components in the BIM model through the geometric feature model; The early warning module is used to issue an early warning warning based on the actual material replacement cost of the building components.

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