Construction project land-saving evaluation method and model based on three-dimensional GIS and BIM fusion technology

Abstract

The invention provides a construction project land-saving evaluation model based on a three-dimensional GIS and BIM fusion technology, and the model comprises the steps: obtaining the position information of ground features based on a BIM model of a construction project, the position information of the ground features being associated with process nodes of the BIM model, and the ground features including persistent ground features and temporary ground features; a directed graph is constructed based on ground feature position information in the BIM model, ground features are connected through a path, and the weight of the path is updated based on the progress of the construction project; on the basis of GIS data of the construction project, associating ground feature position information in the directed graph with geographic information in a GIS model; and adjusting the setting position of the temporary ground feature according to the directed graph and the GIS model, so that the sum of paths associated with the temporary ground feature and the area of the temporary ground feature are reduced. By means of the method, land-saving optimization of the construction process can be achieved.

Description

Technical Field

[0001] The present invention belongs to the field of building information, and particularly relates to a method and model for evaluating land conservation in construction projects based on the integration technology of three-dimensional BIM and GIS. Background Art

[0002] When planning engineering projects, land conservation is a crucial task. To achieve the goal of land conservation, it is necessary to scientifically and reasonably formulate a land conservation measure plan to achieve the overall optimization of land use.

[0003] An important part of formulating land conservation measures for engineering projects is scientific site selection and layout, that is, according to the project characteristics and land use requirements, select a suitable site for construction and reasonably layout buildings and facilities.

[0004] Currently, engineering designs related to land conservation generally start from structural design, the environmental friendliness of engineering raw materials used, and the reuse of temporary land, while there are few reports on smart construction sites and quantitative planning of land conservation.

[0005] Currently, in the construction process of building projects, BIM and GIS have been widely used for project planning and management. If a way can be provided to utilize the existing engineering project data, it can improve the project management level while enhancing the environmental friendliness of the project. Summary of the Invention

[0006] Based on this, it is necessary to provide a method and model for evaluating land conservation in construction projects based on the integration technology of three-dimensional BIM and GIS, which can improve land optimization in the construction project process for the above technical problems.

[0007] According to an embodiment of the present invention, a method for evaluating land conservation in construction projects based on the integration technology of three-dimensional GIS and BIM includes: Based on the BIM model of the construction project, obtain the location information of the ground objects, the location information of the ground objects is associated with the process nodes of the BIM model, and the ground objects include persistent ground objects and temporary ground objects; Construct a directed graph based on the location information of the ground objects in the BIM model, wherein the ground objects are connected by paths, and the weights of the paths are updated based on the progress of the construction project; Based on the GIS model of the construction project, associate the location information of the ground objects in the directed graph with the geographical information in the GIS model; Adjust the setting positions of the temporary ground objects according to the directed graph and the GIS model to reduce the sum of the paths associated with the temporary ground objects and the area of the temporary ground objects.

[0008] According to an embodiment of the present invention, the method for updating the weight of the directed graph includes: Obtain the currently updated project progress based on the updated BIM model of the construction project; Obtain the surface where the features involved in the updated project progress are located; Remove or add updated features on the surface where the features are located according to the type of the updated project progress; And when there are other features on the surface where the updated feature is located, determine the connection relationship between the updated feature and other features on the surface.

[0009] According to an embodiment of the present invention, obtain a sequence of features adjacent to the updated feature based on the BIM model, and determine a second feature having a connection with the updated feature based on the spatial position of the feature sequence and the GIS model; Determine the weights of the updated feature and the second feature based on the state of the second feature, and corresponding to the state that the second feature is unfinished or unused, set the weight from the updated feature to the second feature as the first weight, and set the weight from the second feature to the first feature as the second weight; corresponding to the reachable state between the second feature and the updated feature, set the two-way weights from the updated feature to the second feature as the first weight.

[0010] According to an embodiment of the present invention, determine the reachability between the updated feature and other features on its surface according to the GIS model; When the updated feature is reachable to at least one feature on its surface through the surface, create a connection between the updated feature and the reachable feature; When the updated feature is reachable to at least one feature on its surface through the surface, determine a third feature adjacent to the updated feature based on the BIM model and the shortest path method, and create a connection between the third feature and the updated feature.

[0011] According to an embodiment of the present invention, obtain the alignment points of the building, and associate the vertices corresponding to the alignment points with the geographical positions in the ground layer.

[0012] According to an embodiment of the present invention, update the weights of the directed graph based on the GIS model, and adjust the first weight value of the path based on the passable path determined by the GIS model.

[0013] According to an embodiment of the present invention, adjust the weights based on the actual path information in the construction progress record, wherein the actual path information is determined based on the trajectory set in the construction unit of the construction site.

[0014] According to an embodiment of the present invention, the adjustment of the setting position of the temporary feature according to the directed graph and the GIS model includes: Determine the setting scheme of the temporary feature based on the simulated annealing algorithm, wherein the associated temporary features are arranged based on the spatial constraint conditions; The spatial constraint conditions include determining the spatial positions of associated temporary features based on collision detection and terrain data; The simulated annealing algorithm generates a new setting scheme for temporary features and uses the reduction rate of the total path associated with the temporary features as the evaluation function.

[0015] According to an embodiment of the present invention, the total path associated with the temporary features is determined based on the construction process to be carried out.

[0016] According to an embodiment of the present invention, a land-saving evaluation model for construction projects based on the integration technology of 3D GIS and BIM includes: A feature update unit, based on the BIM model of the construction project, obtains the position information of features. The position information of the features is associated with the process nodes of the BIM model. The features include persistent features and temporary features; A directed graph construction unit constructs a directed graph based on the position information of features in the BIM model. Among them, the features are connected by paths, and the weights of the paths are updated based on the progress of the construction project; A temporary feature adjustment unit associates the position information of features in the directed graph with the geographical information in the GIS model based on the GIS model of the construction project; adjusts the setting positions of the temporary features according to the directed graph and the GIS model to make the paths associated with the temporary features the shortest.

[0017] Through the above method, the conservation of construction project land can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic flowchart of a land-saving evaluation method for construction projects based on the integration technology of 3D GIS and BIM according to an embodiment of the present invention; Figure 2 It is a schematic flowchart for updating the weights of the directed graph in an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] Next, the technical solutions in the present application will be described in conjunction with the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments.

[0020] In the following description, specific details such as specific system structures and technologies are proposed for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, the detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0021] As used herein, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0022] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0023] As used herein, the term "and / or" is merely an associative relationship describing associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0024] According to an embodiment of the present invention, a method for evaluating land conservation in construction projects based on the integration technology of 3D GIS and BIM, referring to Figure 1 as shown, includes: Based on the BIM model of the construction project, obtain the location information of the ground objects, and the location information of the ground objects is associated with the process nodes of the BIM model. The ground objects include persistent ground objects and temporary ground objects; Construct a directed graph based on the location information of the ground objects in the BIM model. Among them, the ground objects are connected by paths, and the weights of the paths are updated based on the progress of the construction project; Based on the GIS model of the construction project, associate the location information of the ground objects in the directed graph with the geographical information in the GIS model; Adjust the setting positions of the temporary ground objects according to the directed graph and the GIS model, so as to reduce the sum of the paths associated with the temporary ground objects and the area of the temporary ground objects.

[0025] As used in the present invention, BIM is the abbreviation of Building Information Modeling. The BIM model is based on the information data of the construction project of the building, and simulates the real state of the building through digital information, including three-dimensional geometric shape information (materials, properties, prices, weights, positions, and progress of building components). Combining with the daily report information during the construction process, the whole process of the project can be tracked during the construction of the building.

[0026] Generally, a BIM model includes multi-purpose BIM models such as a design model, a construction model, a schedule model, a cost model, a manufacturing model, and an operation model. In the present invention, since the land saving of a construction project mainly involves the area outside the ground building, it is more closely related to the schedule model and the construction model in the BIM model. In the following embodiments, the schedule information in the BIM model is updated during the construction process, and after the construction object completes a stage of construction tasks, a new construction boundary is formed inside the building.

[0027] Obviously, BIM is an important digital tool for engineering design, construction, and management. However, only using BIM cannot complete the project management completely. Based on this, the present invention combines BIM and GIS to complete the task of land saving.

[0028] In the present invention, through the BIM model of a construction project, the position information of ground objects is obtained. Here, ground objects are relatively fixed objects on the ground. Corresponding to this are movable vehicles such as construction machinery. Objects formed during the construction process, such as construction residences, areas covered with geotextiles, and starting points of surface paths, are all ground objects. And ground objects can be further divided into temporary ground objects and permanent ground objects according to their properties. The present invention provides an optimized solution for the impact of temporary ground objects on construction projects.

[0029] The building of the BIM model can obtain the coordinates of the building surface through the tools provided by the software. Taking Revit software as an example, the coordinates published from the general layout to the single building drawing can be obtained.

[0030] After obtaining the coordinates of the ground objects, a graph network is constructed for all the ground objects. The nodes of the graph network and the connections between the nodes are updated according to the project construction progress. It should be understood that when the nodes change, the graph network is also updated. The graph network is a directed graph network, and the weights or costs from one node to another may not be the same, that is, one vertex can reach another vertex, but vice versa may not be possible. In some embodiments of the present invention, a relatively large weight can be set for nodes that are not reachable in the reverse direction, so that when calculating the passing cost of a path, such as using an unformed path and the path length as the cost function, a relatively large value will always be obtained; while for the paths between spatially reachable ground objects, the value corresponding to the cost function is relatively low. For example, when there is an area covered with geotextiles, a relatively low weight is set between the corresponding polygons of this area, and a relatively large weight is set for the path points across two geotextiles, so that when optimizing the route, the dust-proof area covered with geotextiles will not be selected to cross.

[0031] Furthermore, simply considering the BIM model without taking into account information such as weather and surface objects, so in combination with the GIS model, the BIM model and the GIS model are associated. The association process mainly involves alignments such as edges, shapes, or key points. Since the coordinate system of BIM is the position relative to the origin, it is necessary to associate its coordinates with those of the geographic coordinate system, so as to ensure that when calculating the nodes of the surface calculation graph network later, the model and the geographic information are registered. The present invention constructs a graph network. Therefore, when some points are aligned, the spatial coordinates of the vertices in the graph network, that is, the position information of the ground objects, are also relatively determined. For geographic registration, reference can be made to the BIM model registration of ArcGIS, and other source data can be referred to accordingly.

[0032] After determining the geographic coordinate system of the graph network, by changing the temporary ground objects therein and calculating the corresponding paths, a land-saving model is achieved, that is, the change of each node in the graph network will cause the change of the paths related to the temporary ground objects, and these paths are associated with the cost of the engineering project. Under the condition of ensuring less occupation of temporary ground objects and shorter paths, the effect of saving land can be achieved.

[0033] It should be realized that after determining the directed graph network, it itself has the function of calculation. For example, the sum of the path lengths between the temporary ground objects and each ground object can be calculated to judge whether the position is reasonable by calculating the paths between the setting position of the temporary ground object and each ground object, and the reasonable occupation can be determined by adjusting the occupation of the ground object and then the influence on the walking paths of vehicles and personnel. Adjusting the occupation of the ground object mainly involves, for example, the combined use of processing sites to reduce the proportion, and ensuring that the total path sum with the relevant sites is reduced, so as to avoid affecting the construction efficiency while reducing the occupation. According to an embodiment of the present invention, refer to Figure 2 As shown, the method for updating the weight of the directed graph includes: Obtaining the currently updated project progress based on the update of the BIM model of the construction project; Obtaining the surface where the ground objects involved in the updated project progress are located; Removing or adding updated ground objects on the surface where the ground objects are located according to the type of the updated project progress; And when there are other ground objects on the surface where the updated ground object is located, determining the connection relationship between the updated ground object and other ground objects on the surface.

[0034] The directed graph of the present invention can be updated according to the progress of the project, wherein the update of the project is obtained through the BIM model, and the updated components and the surfaces involved are obtained through the updated content, and then the graph network can be updated. Since the updated content in the BIM model is updated sequentially in most cases, that is, it is relatively rare to complete the construction of multiple construction units in the same time period, in most cases, when calculating the land saving of the project involving the ground, only one component is considered at a time. Therefore, when a project progress is updated, only the changes in the ground objects and the surfaces involved are considered. If there is an updated progress that does not involve the ground objects, it will not be considered for inclusion in the land saving model calculation; otherwise, the relationship between the ground object and other ground objects is updated based on the surface where the ground object is located.

[0035] In most cases, the surfaces involved in the features are all construction sites; when the features involve different surfaces, the corresponding altitudes in the GIS model are different, but since the points at different altitudes in the directed graph network do not have connections, they have no effect on the calculation process.

[0036] According to one embodiment of the present invention, a feature sequence adjacent to the updated feature is obtained based on the BIM model, and a second feature connected between the features is determined and updated based on the spatial position of the feature sequence and the GIS model; The weights of the updated feature and the second feature are determined based on the status of the second feature, and corresponding to a status where the second feature is unfinished or unused, the weight between the updated feature and the second feature is set to the first weight, and the weight between the second feature and the first feature is set to the second weight; corresponding to a status where the second feature and the updated feature are reachable, the bidirectional weights between the updated feature and the second feature are both set to the first weight.

[0037] In this way, the graph network can be updated. For example, at the beginning of the project, if the surface is selected as the ground surface, when the feature is completed, a new feature is constructed accordingly, and when the new feature is updated, the graph network is updated. When updating the graph network, the updated content includes the constructed features, the path points of the ground path connecting the features, and other information. That is, when there are no features in the plane to which it belongs, only the vertices of the graph network corresponding to the surface are created; and when the surface to which it belongs contains multiple features, it is necessary to select adjacent features, and determine and update the second feature connected to the features according to their spatial position and GIS model. Here, the GIS model is needed to update the BIM model in time, which will cause calculation deviations, and the commonly used GIS information can provide additional reference information to identify disconnected paths, so as to obtain the second feature directly associated with the updated feature. When the updated features are different, the meaning of the corresponding second features is also different. The second feature can be in a completed, used, or unused state, that is, when an unfinished feature is introduced, a measurable path and is provided in the process of calculating the project using the graph network.

[0038] After determining the second feature, accordingly determine the weights of the graph network based on whether the path is reachable, and use passability or reachability as the basis for assigning weights. When it is reachable, the passing cost is lower. For example, when it is passable, the cost can be set to 1, and when it is impassable, the cost is set to 10.

[0039] According to an embodiment of the present invention, determine the reachability of the updated feature and other features on its surface according to the GIS model; When the updated feature and at least one feature on its surface are reachable through the surface, create a connection between the updated feature and the reachable feature; When the updated feature and at least one feature on its surface are reachable through the surface, determine the third feature adjacent to the updated feature based on the BIM model and the shortest path method, and create a connection between the third feature and the updated feature.

[0040] In this way, the reachable path of the updated feature can be determined based on information such as terrain and surface objects, and the vertices reachable on the surface can be determined for each updated feature and its adjacent vertices according to the information provided by the GIS model, thereby enriching the connections and edges between the networks, and further enabling a shorter path to be obtained when calculating the passing path.

[0041] According to an embodiment of the present invention, obtain the alignment points of the building, and associate the vertices corresponding to the alignment points with the geographical locations in the ground layer.

[0042] Although the geographical registration of BIM data such as Revit can be performed, the actual calculation is mainly based on the positions of the entrances and exits of some features provided by BIM. Therefore, in some cases (such as ground leveling), only consider the alignment points of the building (i.e., the project base point or the survey point), and align the points in the graph network on the GIS through the alignment points, that is, the integration of the graph network and GIS information mentioned above can be achieved.

[0043] According to an embodiment of the present invention, update the weights of the directed graph based on the GIS model, and adjust the first weight value of the path based on the passable path determined by the GIS model.

[0044] In this way, when the GIS model is updated, such as when simulating that bad weather causes path changes or bad weather affects passage, the weights of the directed graph network can be updated.

[0045] According to an embodiment of the present invention, adjust the weights based on the actual path information in the record of the construction progress, where the actual path information is determined based on the trajectory set by the construction unit at the construction site.

[0046] It should be understood that the graph network cannot exhaust all passable nodes. Among the data resources generated during the construction process, the trajectory records can not only be used for tracking illegal operation behaviors, but also for path discovery. When discovering a new path based on the path information, the graph network can be updated accordingly.

[0047] The update related to the path can be carried out in the following way: obtain the path of the vehicle, extract the geographical coordinates of the key points of the vehicle path, obtain the coordinates of the vehicle path points within the BIM model based on the BIM model and the GIS model, create vertices and / or connections in the directed graph network according to the corresponding coordinates, and set the weights of the connections.

[0048] According to an embodiment of the present invention, the adjustment of the setting position of the temporary features according to the directed graph and the GIS model includes: Determine the setting scheme of the temporary features based on the simulated annealing algorithm, wherein the associated temporary features are arranged based on the spatial constraint conditions; The spatial constraint conditions include determining the spatial positions of the associated temporary features based on collision detection and terrain data; The simulated annealing algorithm generates a new setting scheme of the temporary features, and uses the reduction rate of the total path associated with the temporary features as the evaluation function.

[0049] It should be realized that after the directed graph network is determined, it itself has the function of calculation. After some rules are determined, the layout optimization of the temporary features can be carried out with the help of algorithms such as the simulated annealing algorithm. Some of the steps may include: Determine the range of positions where the temporary features can be set, the types, and the setting order; Set the temporary features within the range where the temporary features can be set according to the setting order of the temporary features; Update the directed graph network based on the setting of the temporary features; Calculate the total path associated with the temporary features based on the directed graph network.

[0050] Among them, the total path associated with the temporary features can be understood as the path of the vehicle or person from the temporary features to the construction features, and the calculation is not carried out when a construction feature is completed or the feature is in an unconstructed state.

[0051] The simulated annealing algorithm is mainly used to determine the setting order, position, and occupied area of the temporary features. After generating an initial solution, a new layout scheme is generated according to the current solution. If the corresponding total path is shorter, the new scheme is accepted; otherwise, the new layout scheme is accepted according to the conditional probability.

[0052] It should be noted that the generation of new solutions should consider model detection and terrain data to avoid layouts that cannot be implemented in reality. In addition, if the construction of an engineering project involves the implementation of standards, separate rules need to be written to filter out layout plans that do not meet the requirements.

[0053] According to an embodiment of the present invention, the total path associated with the temporary features is determined based on the construction process to be carried out.

[0054] The method for saving land can be planned before the project starts or optimized during the process. When optimizing the land use of a construction project, the calculated path sum considered is the path associated with the temporary features related to the construction process.

[0055] According to an embodiment of the present invention, a land-saving evaluation model for construction projects based on the integration technology of 3D GIS and BIM includes: A feature update unit, based on the BIM model of the construction project, obtains the location information of the features. The location information of the features is associated with the process nodes of the BIM model. The features include persistent features and temporary features; A directed graph construction unit, based on the location information of the features in the BIM model, constructs a directed graph. Among them, the features are connected by paths, and the weights of the paths are updated based on the progress of the construction project; A temporary feature adjustment unit, based on the GIS model of the construction project, associates the location information of the features in the directed graph with the geographical information in the GIS model; adjusts the set positions of the temporary features according to the directed graph and the GIS model to make the path associated with the temporary features the shortest.

[0056] The embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program runs on an electronic device, the electronic device is enabled to execute the foregoing method.

[0057] The embodiment of the present application also provides a computer program product, including: computer program code. When the computer program code runs on an electronic device, the electronic device is enabled to execute the foregoing method.

[0058] The embodiment of the present application also provides a chip, including: a processor, configured to call and run a computer program from a memory, so that an electronic device installed with the chip executes the foregoing method.

[0059] From the descriptions of the above embodiments, those skilled in the art can understand that, for the convenience and brevity of description, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0060] It should be understood that the devices and processes disclosed in several embodiments provided in this application can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another device. In addition, some features can be ignored or not executed. In addition, the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of devices or units can be in electrical, mechanical or other forms.

[0061] The units described as separate components can be physically separated or not. The components displayed as units can be a physical unit or multiple physical units. That is, they can be located in one place or distributed to multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of this solution.

[0062] In addition, each functional unit in various embodiments of this application can be integrated in a processing unit; it can also exist physically separately; it can also be that some units are integrated in one unit and some units exist physically separately. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0063] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, all or part of the technical solutions of the embodiments of this application can be embodied in the form of a software product. This software product is stored in a storage medium. This software product includes several instructions to enable a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods in various embodiments of this application. The aforementioned storage medium includes: USB flash drives, mobile hard disks, ROM, RAM, magnetic disks or optical disks and other various media that can store program codes.

[0064] It should be noted that all or part of the above-mentioned various embodiments provided in this application (for example, part or all of any feature) can be arbitrarily combined or used with each other.

[0065] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims described above.

Claims

1. A construction project land saving evaluation method based on 3D GIS and BIM fusion technology, characterized in that: include: Based on the BIM model of the construction project, obtaining location information of the ground objects, wherein the location information of the ground objects is associated with the process nodes of the BIM model, and the ground objects include permanent ground objects and temporary ground objects; Construct a directed graph based on the location information of objects in the BIM model, where objects are connected by paths, and the weight of the paths is updated based on the progress of the construction project; Based on the GIS model of the construction project, the location information of the objects in the directed graph is associated with the geographic information in the GIS model; The location of temporary features is adjusted according to the directed graph and the GIS model, so that the sum of the paths associated with the temporary features and the area of ​​the temporary features are reduced.

2. A construction project land saving evaluation method based on 3D GIS and BIM fusion technology as claimed in claim 1, characterized in that: The weight updating method of the directed graph comprises: Get the current updated project progress based on the update of the BIM model of the construction project; Obtain the surface of the ground objects involved in the updated project progress; According to the type of updated engineering progress, remove or add updated features on the surface where the features are located; When other objects exist on the surface where the updated object is located, the connection relationship between the updated object and the other objects on the surface is determined.

3. A construction project land saving evaluation method based on 3D GIS and BIM fusion technology as claimed in claim 2, characterized in that: Obtain a feature sequence adjacent to the updated feature based on the BIM model, and determine and update a second feature connected between the features based on the spatial position of the feature sequence and the GIS model; The weights of the updated feature and the second feature are determined based on the status of the second feature, and corresponding to a status where the second feature is unfinished or unused, the weight between the updated feature and the second feature is set to the first weight, and the weight between the second feature and the first feature is set to the second weight; corresponding to a status where the second feature and the updated feature are reachable, the bidirectional weights between the updated feature and the second feature are both set to the first weight.

4. A construction project land saving evaluation method based on 3D GIS and BIM fusion technology as claimed in claim 2, characterized in that: Determine the accessibility of the updated feature and other features on the surface based on the GIS model; When the updated feature and at least one feature of the located surface are reachable through the located surface, creating a connection between the updated feature and the reachable feature; When the updated feature and at least one feature on the surface are reachable through the surface, a third feature adjacent to the feature is determined and updated based on the BIM model and the shortest path method, and a connection is created between the third feature and the updated feature.

5. A construction project land saving evaluation method based on 3D GIS and BIM fusion technology as claimed in claim 1, characterized in that: Get the alignment point of the building, and associate the vertex corresponding to the alignment point with the geographic location in the ground layer.

6. A construction project land saving evaluation method based on 3D GIS and BIM fusion technology as claimed in claim 5, characterized in that: The weight of the directed graph is updated based on the GIS model, and the first weight value of the path is adjusted based on the traversable path determined by the GIS model.

7. A construction project land saving evaluation method based on 3D GIS and BIM fusion technology as claimed in claim 6, characterized in that: The weights are adjusted based on actual path information in the record of the construction progress, wherein the actual path information is determined based on a trajectory set at a construction unit at the construction site.

8. The construction project land saving evaluation method based on the fusion technology of three-dimensional GIS and BIM as claimed in claim 1 is characterized in that: The adjusting of the setting position of the temporary land feature according to the directed graph and the GIS model includes: Determine the setting scheme of temporary features based on simulated annealing algorithm, wherein the arrangement of associated temporary features is performed based on spatial constraints; The spatial constraint conditions include determining the spatial position of associated temporary features based on collision detection and terrain data; The simulated annealing algorithm generates a new arrangement plan for temporary features, and uses the reduction rate of the sum of paths associated with the temporary features as an evaluation function.

9. A construction project land saving evaluation method based on 3D GIS and BIM fusion technology as claimed in claim 8, characterized in that: The total number of paths associated with the temporary features is determined based on the construction process to be performed.

10. A construction project land saving evaluation model based on 3D GIS and BIM fusion technology, characterized in that: include: A feature updating unit, based on a BIM model of a construction project, obtains location information of features, wherein the location information of the features is associated with a process node of the BIM model, and the features include permanent features and temporary features; A directed graph construction unit, which constructs a directed graph based on the location information of objects in the BIM model, wherein objects are connected by paths, and the weight of the paths is updated based on the progress of the construction project; The temporary feature adjustment unit associates the feature location information in the directed graph with the geographic information in the GIS model based on the GIS model of the construction project; adjusts the location of the temporary features according to the directed graph and the GIS model to make the path associated with the temporary features the shortest.

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