Protective device design method and system based on BIM technology

Abstract

The application discloses a protection device design method and system based on BIM technology, and the method comprises the following steps: photographing and scanning a target slope by using a drone to obtain contour data of the target slope and image data corresponding to the contour data; BIM modeling is performed on the target slope according to the contour data to form a slope model; a risk source of the target slope is obtained according to the image data, and the risk source is mapped to the slope model; the expected risk of each risk source is calculated according to the position of the risk source on the slope model, and a protection device of the target slope is designed according to the expected risk. The application can be applied to the protection design of various high slopes, reduces the manual survey part in the slope survey process, effectively reduces the risk caused by manual survey, improves the risk source identification efficiency, guarantees the effectiveness of subsequent protection design, and improves the slope protection efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the computer-aided design technology, and particularly to a protection device design method and system based on BIM technology. BACKGROUND

[0002] Dangerous rock generally refers to a rock mass on a cliff or steep slope, which is cut by multiple sets of structural surfaces, and is in an unstable, sub-stable or limit equilibrium state under the action of gravity, weathering force, ground stress, earthquake, fissure water pressure and the like. Once the dangerous rock loses stability and forms collapse and rockfall, it may lead to disastrous consequences and cause serious losses. In some mountainous areas, due to high mountains and deep valleys, steep terrain, vegetation development, strong structure and widespread dangerous rock, it is difficult to check the distribution of dangerous rock and the structure of dangerous rock by conventional surveying means, thereby affecting the generation of subsequent design schemes. SUMMARY

[0003] In order to at least overcome the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a protection device design method and system based on BIM technology.

[0004] In a first aspect, the embodiments of the present application provide a protection device design method based on BIM technology, comprising:

[0005] acquiring contour data of the target slope and image data corresponding to the contour data by photographing and scanning the target slope by a UAV;

[0006] forming a slope model by BIM modeling the target slope according to the contour data;

[0007] acquiring risk sources of the target slope according to the image data, and mapping the risk sources to the slope model;

[0008] calculating the expected risk of each risk source according to the position of the risk source on the slope model, and designing a protection device for the target slope according to the expected risk.

[0009] In the implementation of the embodiments of the present application, for a target slope, corresponding profile data and image data are acquired by photographing and scanning through a UAV, wherein the profile data can be used for BIM modeling of the slope. For a UAV integrating photographing and scanning, the data acquired by photographing and scanning have a corresponding relationship, so that after a risk source is acquired from the image data, the position of the risk source in the image can be mapped to the profile data and further mapped to the slope model. The risk source acquired through image processing can calculate the expected risk caused by the risk source. In the embodiments of the present application, the expected risk is rockfall risk, that is, the possible rockfall trajectory is calculated according to the position of the risk source, so as to further design a protection device. The above technical means can be applied to the protection design of various high slopes, reduces the manual survey part in the slope survey process, effectively reduces the risk caused by manual survey, improves the risk source identification efficiency, ensures the effectiveness of subsequent protection design, and improves the slope protection efficiency.

[0010] In a possible implementation, acquiring a risk source of the target slope according to the image data and mapping the risk source to the slope model comprises:

[0011] performing image detection on the image data to identify the risk source;

[0012] acquiring position information of the risk source in the image data, and marking the risk source in the corresponding profile data through the position information;

[0013] mapping the risk source marked in the profile data to the slope model.

[0014] In a possible implementation, performing image detection on the image data to identify the risk source comprises:

[0015] identifying an abnormal area on a slope surface in the image data through edge detection; the abnormal area is an area with a difference value of pixel value from a surrounding area pixel value less than a preset value, and the preset value is a negative value;

[0016] acquiring a rockfall area in the image data in an area below a slope toe as an actual rockfall area;

[0017] identifying the risk source according to the abnormal area and the actual rockfall area.

[0018] In a possible implementation, identifying the risk source according to the abnormal area and the actual rockfall area comprises:

[0019] taking the abnormal area as a first risk source, and calculating a rockfall area generated by the first risk source as a first rockfall area;

[0020] a part of the actual rockfall region that does not overlap with the first rockfall region as a second rockfall region;

[0021] performing rockfall inversion according to the second rockfall region to generate a corresponding second risk source;

[0022] the first risk source and the second risk source as the risk sources.

[0023] In a possible implementation, performing rockfall inversion according to the second rockfall region to generate a corresponding second risk source includes:

[0024] obtaining at least two first rockfall regions closest to the second rockfall region as matching rockfall regions matched with the second rockfall region;

[0025] obtaining a center point coordinate of the second rockfall region in the image data as a second center point coordinate, and obtaining a center point coordinate of the matching rockfall region corresponding to the second rockfall region in the image data as a first center point coordinate;

[0026] calculating a horizontal coordinate gradient of the second center point coordinate and all first center point coordinates, and calculating a vertical coordinate gradient of the second center point coordinate and all first center point coordinates;

[0027] obtaining a horizontal coordinate of the second risk source by interpolating coordinates of the first risk source corresponding to the matching rockfall region according to the horizontal coordinate gradient, and obtaining a vertical coordinate of the second risk source by interpolating coordinates of the first risk source corresponding to the matching rockfall region according to the vertical coordinate gradient;

[0028] determining a position of the second risk source according to the horizontal coordinate of the second risk source and the vertical coordinate of the second risk source.

[0029] In a possible implementation, calculating an expected risk of each risk source according to a position of the risk source on the slope model, and designing a protection device of the target slope according to the expected risk.

[0030] calculating a rockfall trajectory of the risk source as the expected risk of the risk source;

[0031] designing a protection device of the target slope according to the rockfall trajectory.

[0032] In a second aspect, the embodiments of the present application further provide a protection device design system based on BIM technology, including:

[0033] an obtaining unit configured to obtain contour data of a target slope and image data corresponding to the contour data by photographing and scanning the target slope by a drone.

[0034] The modeling unit is configured to perform BIM modeling on the target slope based on the contour data to form a slope model;

[0035] The mapping unit is configured to obtain the risk sources of the target slope based on the image data and map the risk sources to the slope model;

[0036] The design unit is configured to calculate the expected risk of each risk source based on its location on the slope model, and to design a protective device for the target slope based on the expected risk.

[0037] In one possible implementation, the mapping unit is further configured as follows:

[0038] The image data is used for image detection to identify the sources of risk;

[0039] Obtain the location information of the risk source in the image data, and mark the risk source in the corresponding contour data using the location information;

[0040] The risk sources marked in the contour data are mapped to the slope model.

[0041] In one possible implementation, the mapping unit is further configured as follows:

[0042] Abnormal regions on the slope surface in the image data are identified by edge detection; the abnormal region is a region where the difference between the pixel value and the pixel value of the surrounding region is less than a preset value, and the preset value is a negative value;

[0043] The rockfall area located below the toe of the slope in the image data is taken as the actual rockfall area.

[0044] The risk source is identified based on the abnormal area and the actual rockfall area.

[0045] In one possible implementation, the mapping unit is further configured as follows:

[0046] The abnormal area is taken as the first risk source, and the rockfall area generated by the first risk source is calculated as the first rockfall area.

[0047] The portion of the actual rockfall area that does not overlap with the first rockfall area is designated as the second rockfall area.

[0048] Based on the second rockfall area, a corresponding second risk source is generated through rockfall inversion;

[0049] The first risk source and the second risk source are defined as the risk sources.

[0050] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0051] This invention relates to a protection device design method and system based on BIM technology, which can be applied to the protection design of various high slopes. It reduces the manual survey part in the slope survey process, effectively reduces the risks caused by manual survey, improves the efficiency of risk source identification, ensures the effectiveness of subsequent protection design, and improves the efficiency of slope protection. Attached Figure Description

[0052] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0053] Figure 1 This is a schematic diagram of the method steps in an embodiment of this application;

[0054] Figure 2 This is a schematic diagram illustrating risk source identification in an embodiment of this application. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0056] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0057] Please see Figure 1The diagram illustrates the steps of the protective device design method based on BIM technology in an embodiment of this application. Further, the protective device design method based on BIM technology includes the following steps S1 to S4:

[0058] S1: The target slope is photographed and scanned by a drone to obtain the contour data of the target slope and the corresponding image data;

[0059] S2: Based on the contour data, perform BIM modeling on the target slope to form a slope model;

[0060] S3: Obtain the risk sources of the target slope based on the image data, and map the risk sources to the slope model;

[0061] S4: Calculate the expected risk of each risk source based on its location on the slope model, and design a protection device for the target slope based on the expected risk.

[0062] In the implementation of this application embodiment, for the target slope, it is necessary to use a drone to take photos and scan to obtain corresponding contour data and image data. The contour data can be used for BIM modeling of the slope. For drones that integrate photography and scanning, the data obtained by photography and scanning have a corresponding relationship. Therefore, after obtaining the risk source through image data, the position of the risk source in the image can be mapped to the contour data, and further mapped to the slope model. The risk source obtained through image processing can calculate the expected risk generated by the risk source. In this application embodiment, the expected risk is the risk of falling rocks, that is, the possible trajectory of falling rocks is calculated based on the location of the risk source, thereby further designing the protective device. Through the above-mentioned technical means, this application can be applied to the protection design of various high slopes, reducing the manual survey part in the slope survey process, effectively reducing the risks caused by manual surveys, improving the efficiency of risk source identification, ensuring the effectiveness of subsequent protection design, and improving the efficiency of slope protection.

[0063] In one possible implementation, obtaining the risk sources of the target slope based on the image data and mapping the risk sources to the slope model includes:

[0064] The image data is used for image detection to identify the sources of risk;

[0065] Obtain the location information of the risk source in the image data, and mark the risk source in the corresponding contour data using the location information;

[0066] The risk sources marked in the contour data are mapped to the slope model.

[0067] In the implementation of this application embodiment, during the scanning and photographing process of the UAV, the scanning data and photographing data correspond to the corresponding flight data. The UAV generates and stitches contour data and image data based on this data, which is existing technology and is not limited in this application embodiment. Based on these generated image data, risk sources can be identified through image detection. The corresponding position of the risk source in the image data can be represented in the contour data, and further represented in the slope model.

[0068] In one possible implementation, image detection to identify risk sources from the image data includes:

[0069] Abnormal regions on the slope surface in the image data are identified by edge detection; the abnormal region is a region where the difference between the pixel value and the pixel value of the surrounding region is less than a preset value, and the preset value is a negative value;

[0070] The rockfall area located below the toe of the slope in the image data is taken as the actual rockfall area.

[0071] The risk source is identified based on the abnormal area and the actual rockfall area.

[0072] In implementing this application's embodiments, the inventors discovered in practice that the most likely risk sources on the slope surface are areas where rockfalls have occurred. In one scenario, after a rockfall, the exposed rock surface is lighter in color relative to the surrounding vegetation; in another scenario, the vegetation that grows after a rockfall is relatively new, and its color is also lighter than the surrounding vegetation. Therefore, in this application's embodiments, the inventors can identify light-colored abnormal areas as part of the risk sources through edge detection. It should be understood that, in addition to rockfall areas, light-colored areas may also include trails, ditches, etc., which can be identified and screened manually. However, besides the abnormal areas obtained through image recognition, there may be unidentified risk sources. Therefore, it is necessary to further identify the actual rockfall areas and then further identify the unidentified risk sources within these areas to improve the accuracy of the identification.

[0073] In one possible implementation, identifying the risk source based on the abnormal area and the actual rockfall area includes:

[0074] The abnormal area is taken as the first risk source, and the rockfall area generated by the first risk source is calculated as the first rockfall area.

[0075] The portion of the actual rockfall area that does not overlap with the first rockfall area is designated as the second rockfall area.

[0076] Based on the second rockfall area, a corresponding second risk source is generated through rockfall inversion;

[0077] The first risk source and the second risk source are defined as the risk sources.

[0078] In the implementation of this application embodiment, a specific risk source identification scheme is provided. An abnormal region identified in the image can be used as a first risk source. A first rockfall region can be generated by calculating the falling rocks from the first risk source. This calculation can be performed by simulating different types of falling rocks using kinetic energy, such as using the Rockfall software. The calculated first rockfall region may differ from the actual rockfall region; the difference represents falling rocks from unidentified risk sources. This portion is then used as a second rockfall region, and rockfall inversion is performed to generate a second risk source. This method effectively identifies risk sources missed during the image recognition process.

[0079] In one possible implementation, generating a corresponding second risk source based on the second rockfall area through rockfall inversion includes:

[0080] Obtain at least two first rockfall areas that are closest to the second rockfall area as matching rockfall areas that match the second rockfall area;

[0081] The coordinates of the center point of the second rockfall area in the image data are obtained as the second center point coordinates, and the coordinates of the matching rockfall area corresponding to the second rockfall area in the image data are obtained as the first center point coordinates.

[0082] Calculate the horizontal coordinate gradient of the second center point coordinates and all first center point coordinates, and calculate the vertical coordinate gradient of the second center point coordinates and all first center point coordinates;

[0083] The horizontal coordinates of the second risk source are obtained by interpolating the coordinates of the first risk source corresponding to the matched rockfall area according to the horizontal coordinate gradient, and the vertical coordinates of the second risk source are obtained by interpolating the coordinates of the first risk source corresponding to the matched rockfall area according to the vertical coordinate gradient.

[0084] The location of the second risk source is determined based on its horizontal and vertical coordinates.

[0085] When implementing the embodiments of this application, please refer to Figure 2This diagram illustrates the interpolation generation of the second risk source. The second risk source corresponding to the second rockfall area is obtained through interpolation of the first risk source. The matching rockfall area is defined as at least two first rockfall areas that are closest to the location of the second rockfall area; the closer the locations, the closer the terrain corresponding to the rockfall. In this embodiment, horizontal and vertical gradients can be formed using the coordinates of the second and first center points. The horizontal gradient represents the horizontal position of the second risk source, while the vertical gradient represents its vertical position. It should be understood that in image data, the vertical direction generally corresponds to the slope direction. For a rockfall area, the vertical direction generally represents the kinetic energy of the rockfall, i.e., the vertical position of the risk source on the slope. The horizontal direction represents the approximate horizontal position of the rockfall starting point, thus representing the horizontal position of the risk source on the slope. By interpolating the horizontal and vertical positions, the location of the corresponding second risk source can be obtained.

[0086] In one possible implementation, the expected risk of each risk source is calculated based on its location on the slope model, and a protective device for the target slope is designed based on the expected risk.

[0087] The trajectory of the falling rocks from the risk source is calculated as the expected risk of the risk source;

[0088] Design a protective device for the target slope based on the rockfall trajectory.

[0089] When implementing the embodiments of this application, after obtaining the corresponding rockfall trajectory of the risk source, corresponding protective measures can be designed for the rockfall trajectory, such as reinforcing the risk source itself or protecting the rockfall through active / passive protective nets.

[0090] Based on the same inventive concept, embodiments of this application also provide a protective device design system based on BIM technology, including:

[0091] The acquisition unit is configured to acquire contour data of the target slope and image data corresponding to the contour data by taking pictures and scanning the target slope with a drone;

[0092] The modeling unit is configured to perform BIM modeling on the target slope based on the contour data to form a slope model;

[0093] The mapping unit is configured to obtain the risk sources of the target slope based on the image data and map the risk sources to the slope model;

[0094] The design unit is configured to calculate the expected risk of each risk source based on its location on the slope model, and to design a protective device for the target slope based on the expected risk.

[0095] In one possible implementation, the mapping unit is further configured as follows:

[0096] The image data is used for image detection to identify the sources of risk;

[0097] Obtain the location information of the risk source in the image data, and mark the risk source in the corresponding contour data using the location information;

[0098] The risk sources marked in the contour data are mapped to the slope model.

[0099] In one possible implementation, the mapping unit is further configured as follows:

[0100] Abnormal regions on the slope surface in the image data are identified by edge detection; the abnormal region is a region where the difference between the pixel value and the pixel value of the surrounding region is less than a preset value, and the preset value is a negative value;

[0101] The rockfall area located below the toe of the slope in the image data is taken as the actual rockfall area.

[0102] The risk source is identified based on the abnormal area and the actual rockfall area.

[0103] In one possible implementation, the mapping unit is further configured as follows:

[0104] The abnormal area is taken as the first risk source, and the rockfall area generated by the first risk source is calculated as the first rockfall area.

[0105] The portion of the actual rockfall area that does not overlap with the first rockfall area is designated as the second rockfall area.

[0106] Based on the second rockfall area, a corresponding second risk source is generated through rockfall inversion;

[0107] The first risk source and the second risk source are defined as the risk sources.

[0108] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0109] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices or units, or may be electrical, mechanical or other forms of connection.

[0110] The units described as separate components may or may not be physically separate. As will be apparent to those skilled in the art, the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0111] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0112] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or grid device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0113] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for designing a protective device based on BIM technology, characterized in that, The method comprises: acquiring contour data and image data corresponding to the contour data of the target slope by photographing and scanning the target slope by a UAV; forming a slope model by BIM modeling of the target slope according to the contour data; acquiring risk sources of the target slope according to the image data, and mapping the risk sources to the slope model; calculating the expected risk of each risk source according to the position of the risk source on the slope model, and designing a protective device for the target slope according to the expected risk; the image detection of the image data to identify risk sources comprises: identifying abnormal areas on the slope surface in the image data by edge detection; the abnormal area is an area with a pixel value difference from the surrounding area less than a preset value, and the preset value is a negative value; acquiring a rockfall area in the image data below the slope toe as an actual rockfall area; identifying the risk sources according to the abnormal areas and the actual rockfall area; the identification of the risk sources according to the abnormal areas and the actual rockfall area comprises: taking the abnormal area as a first risk source, and calculating the rockfall area generated by the first risk source as a first rockfall area; taking the part of the actual rockfall area that does not overlap with the first rockfall area as a second rockfall area; generating a corresponding second risk source by rockfall inversion according to the second rockfall area; taking the first risk source and the second risk source as the risk sources; the generation of the corresponding second risk source by rockfall inversion according to the second rockfall area comprises: acquiring at least two first rockfall areas closest to the second rockfall area as matching rockfall areas matched with the second rockfall area; acquiring the center point coordinates of the second rockfall area in the image data as second center point coordinates, and acquiring the center point coordinates of the matching rockfall areas corresponding to the second rockfall area in the image data as first center point coordinates; calculating the horizontal coordinate gradient of the second center point coordinates and all first center point coordinates, and calculating the vertical coordinate gradient of the second center point coordinates and all first center point coordinates; interpolating the coordinates of the first risk sources corresponding to the matching rockfall areas to obtain the horizontal coordinates of the second risk sources according to the horizontal coordinate gradient, and interpolating the coordinates of the first risk sources corresponding to the matching rockfall areas to obtain the vertical coordinates of the second risk sources according to the vertical coordinate gradient; determining the position of the second risk source according to the horizontal coordinates of the second risk source and the vertical coordinates of the second risk source.

2. The BIM technology-based design method of a protective device according to claim 1, wherein, The acquisition of the risk sources of the target slope according to the image data and the mapping of the risk sources to the slope model comprises: image detection of the image data to identify risk sources; acquiring position information of the risk sources in the image data, and marking the risk sources in the corresponding contour data through the position information; mapping the marked risk sources in the contour data to the slope model.

3. The BIM technology-based design method of a protective device according to claim 1, wherein, According to the position of the risk source on the slope model, the expected risk of each risk source is calculated, and the protection device of the target slope is designed according to the expected risk; The rockfall trajectory of the risk source is calculated as the expected risk of the risk source; The protection device of the target slope is designed according to the rockfall trajectory.

4. A BIM technology-based protection device design system using the method according to any one of claims 1 to 3, characterized by, Comprise: An acquisition unit configured to acquire contour data and image data corresponding to the contour data of a target slope by photographing and scanning the target slope through a UAV; A modeling unit configured to perform BIM modeling on the target slope according to the contour data to form a slope model; A mapping unit configured to acquire risk sources of the target slope according to the image data, and map the risk sources to the slope model; A design unit configured to calculate the expected risk of each risk source according to the position of the risk source on the slope model, and design the protection device of the target slope according to the expected risk.

5. The BIM technology based design system for a protective device according to claim 4, wherein, The mapping unit is further configured to: Image detection is performed on the image data to identify risk sources; Obtain the position information of the risk sources in the image data, and mark the risk sources in the corresponding contour data through the position information; Map the marked risk sources in the contour data to the slope model.

6. The BIM technology based design system for a protective device according to claim 4, wherein, The mapping unit is further configured to: Edge detection is performed to identify abnormal areas on the slope surface in the image data; the abnormal area is an area with a pixel value difference less than a preset value from the pixel value of the surrounding area, and the preset value is a negative value; Obtain the rockfall area in the image data below the slope toe as the actual rockfall area; According to the abnormal area and the actual rockfall area, the risk source is identified.

7. The BIM technology based design system for a protective device according to claim 6, wherein, The mapping unit is further configured to: Take the abnormal area as a first risk source, and calculate the rockfall area generated by the first risk source as a first rockfall area; The part of the actual rockfall area that does not overlap with the first rockfall area is taken as a second rockfall area; According to the second rockfall area, the corresponding second risk source is generated by rockfall inversion; The first risk source and the second risk source are taken as the risk source.

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