BIM (Building Information Modeling)-based tunnel transition section body type and steel bar parametric modeling method

Abstract

The invention relates to the technical field of hydraulic engineering tunnel design, and discloses a BIM (Building Information Modeling)-based tunnel transition section body type and steel bar parametric modeling method. Geometric information of the upstream and the downstream of the tunnel transition section and the upstream and downstream distance are obtained; based on the geometric information, the upstream and the downstream of the tunnel transition section are segmented, and the shape of the tunnel transition section is obtained through lofting operation; and according to the arrangement parameters of the steel bars, the arrangement positions of the steel bars are determined in the tunnel transition section body type, and modeling is completed through BIM. By means of the method, a large amount of modeling work of designers can be liberated, automation of repeated and tedious work is achieved, the three-dimensional BIM model of the tunnel transition section body shape and the reinforcing steel bars is automatically generated, the project design efficiency is greatly improved, and a complete, effective, convenient and rapid method is provided for the designers to design the tunnel transition section body shape and the reinforcing steel bars.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic engineering tunnel design, and particularly to a parametric modeling method for the shape and steel bars of a tunnel transition section based on BIM. Background Art

[0002] As a core water conveyance structure in a water conservancy project, a hydraulic tunnel undertakes multiple functions such as water diversion and power generation, flood control and drainage, and water resource allocation. Its design quality directly affects the overall operation efficiency of the water conservancy project. As a transition structure between tunnels with different cross-section types, the transition section is a key link to ensure smooth water flow connection and reduce local head loss.

[0003] However, the current industry faces the following technical challenges and management dilemmas in the field of transition section design: Design efficiency bottleneck: The traditional design process relies heavily on manual calculation and 2D CAD drawing. It is necessary to repeatedly adjust geometric parameters through the trial algorithm to meet the hydraulic transition requirements. The design cycle of complex transition sections accounts for an important proportion in the overall design working hours of the tunnel, and it is difficult to ensure the optimal solution under multiple constraint conditions.

[0004] Error control problem: Manual calculation is prone to introducing parameter approximation errors, and traditional CAD tools lack a parameter linkage mechanism, resulting in deviations between the plane design and the 3D entity.

[0005] Insufficient dynamic adaptability: In the face of changes in geological conditions or adjustments in functional requirements, existing tools are difficult to quickly achieve shape reconstruction and optimization of steel bar layout.

[0006] Therefore, it is urgent to improve the flexibility and efficiency of tunnel transition section design, which has become an urgent problem to be solved. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides a parametric modeling method for the shape and steel bars of a tunnel transition section based on BIM, including the following steps: Obtain the geometric information of the upstream and downstream of the tunnel transition section and the upstream and downstream distances respectively; Based on the geometric information, divide the upstream and downstream of the tunnel transition section respectively, and obtain the shape of the tunnel transition section through lofting operation; According to the steel bar layout parameters, determine the layout positions of the steel bars in the shape of the tunnel transition section, and complete the modeling through BIM.

[0008] Further, the geometric information includes shape, side length, and diameter.

[0009] Further, based on the shape of the tunnel transition section, tunnel water pressure, and tunnel surrounding rock parameter information, the steel bar layout parameters are obtained through the finite element analysis method.

[0010] Further, based on the geometric information, the upstream and downstream of the tunnel transition section are respectively segmented, and through lofting operations, the shape of the tunnel transition section is obtained, specifically including: Based on the geometric information of the upstream of the tunnel transition section, the upstream of the tunnel transition section is decomposed, projected, and lofting operations are performed to obtain the first connecting surface; Based on the geometric information of the downstream of the tunnel transition section, the downstream of the tunnel transition section is decomposed, reversely projected, and lofting operations are performed to obtain the second connecting surface; According to the upstream surface of the tunnel transition section, the downstream surface of the tunnel transition section, the first connecting surface, and the second connecting surface, an inner contour entity of the tunnel transition section is formed; Based on the geometric information of the upstream of the tunnel transition section and the geometric information of the downstream of the tunnel transition section, a preset distance is respectively offset outward to obtain the outer contour geometric information of the upstream of the tunnel transition section and the outer contour geometric information of the downstream of the tunnel transition section; According to the outer contour geometric information of the upstream of the tunnel transition section and the outer contour geometric information of the downstream of the tunnel transition section, the upstream and downstream of the tunnel transition section are respectively segmented, and through lofting operations, an outer contour entity of the tunnel transition section is obtained; Based on the inner contour entity of the tunnel transition section and the outer contour entity of the tunnel transition section, the shape of the tunnel transition section is determined.

[0011] Further, the step of decomposing, projecting, and performing lofting operations on the upstream of the tunnel transition section based on the geometric information of the upstream of the tunnel transition section to obtain the first connecting surface includes the following steps: Based on the shape and side length in the geometric information of the upstream of the tunnel transition section, the upstream shape is segmented into N upstream line segments in some embodiments, and the midpoint of each upstream line segment is determined; Through the minimum distance projection method, the midpoints of each of the upstream line segments are respectively mapped to the downstream, and corresponding upstream projection points are respectively generated; According to the midpoints of each of the upstream line segments and their corresponding upstream projection points, lofting operations are performed to obtain the first connecting surface.

[0012] Further, the step of decomposing, reversely projecting, and performing lofting operations on the downstream of the tunnel transition section based on the geometric information of the downstream of the tunnel transition section to obtain the second connecting surface includes the following steps: Based on the shape and side length in the geometric information of the downstream of the tunnel transition section, the downstream shape is segmented into M downstream line segments in some embodiments, and the midpoint of each downstream line segment is determined; M and N are in an integer multiple relationship; Through the minimum distance projection method, the midpoints of each of the downstream line segments are respectively mapped to the upstream, and corresponding downstream projection points are respectively generated; Based on the midpoints of each of the downstream line segments and their corresponding downstream projection points, a lofting operation is performed to obtain the second connecting surface.

[0013] Further, forming the inner contour entity of the tunnel transition section according to the upstream surface of the tunnel transition section, the downstream surface of the tunnel transition section, the first connecting surface, and the second connecting surface specifically includes: Based on the geometric information of the upstream of the tunnel transition section, a transformation is performed to obtain the upstream surface of the tunnel transition section; Based on the geometric information of the downstream of the tunnel transition section, a transformation is performed to obtain the downstream surface of the tunnel transition section; The upstream surface of the tunnel transition section, the downstream surface of the tunnel transition section, the first connecting surface, and the second connecting surface are combined to obtain the inner contour entity of the tunnel transition section.

[0014] Further, determining the shape of the tunnel transition section according to the inner contour entity and the outer contour entity of the tunnel transition section is: According to the inner contour entity and the outer contour entity of the tunnel transition section, through a Boolean subtraction operation, the shape of the tunnel transition section is obtained.

[0015] Input: Shape, water pressure, spring stiffness (calculated from surrounding rock parameters) Further, determining the layout position of the steel bars in the shape of the tunnel transition section according to the steel bar layout parameters includes: Obtain the steel bar layout parameters, including the steel bar cover thickness, the diameter and spacing of the main reinforcement, and the diameter and spacing of the distribution reinforcement; According to the steel bar cover thickness, the diameter and spacing of the main reinforcement, determine the main reinforcement positioning line; According to the diameter and spacing of the distribution reinforcement, determine the distribution reinforcement positioning line; According to the main reinforcement positioning line and the distribution reinforcement positioning line, determine the layout position of the steel bars.

[0016] Further, determining the main reinforcement positioning line according to the steel bar cover thickness, the diameter and spacing of the main reinforcement includes the following method: According to the spacing of the main reinforcement, the inner contour and the outer contour of the shape of the tunnel transition section are respectively divided horizontally to obtain the inner contour reference line and the outer contour reference line of the main reinforcement; the horizontal direction is perpendicular to the tunnel extension direction; According to the steel bar cover thickness and the diameter of the main reinforcement, the inner contour reference line of the main reinforcement is offset inward, and the outer contour reference line of the main reinforcement is offset outward to determine the main reinforcement positioning line.

[0017] Further, determining the positioning line of the distribution steel bars according to the diameter and spacing of the distribution steel bars includes the following methods: Dividing the positioning line of the stress steel bars according to the spacing of the distribution steel bars; At the dividing points of the positioning line of the stress steel bars, offset according to the diameter of the distribution steel bars, and then determine the positioning line of the distribution steel bars along the tunnel direction.

[0018] Further, after determining the positioning line of the stress steel bars and the positioning line of the distribution steel bars, it further includes: Respectively, according to each positioning line segment in the positioning line of the stress steel bars and the positioning line of the distribution steel bars, calculate the turning angle to obtain the simplified positioning line of the stress steel bars and the simplified positioning line of the distribution steel bars; Determine the laying positions of the steel bars based on the simplified positioning line of the stress steel bars and the simplified positioning line of the distribution steel bars.

[0019] The embodiments of the present invention have the following technical effects: In this application, the geometric information and the upstream and downstream distances of the upstream and downstream of the tunnel transition section are respectively obtained; based on the geometric information, the upstream and downstream of the tunnel transition section are respectively segmented, and through lofting operations, the shape of the tunnel transition section is obtained; according to the steel bar laying parameters, in the shape of the tunnel transition section, the laying positions of the steel bars are determined, and the modeling is completed through BIM. Designers can quickly and accurately establish the shape of the tunnel transition section and the steel bar model based on the geometric information and the upstream and downstream distances of the building. Therefore, through this parametric modeling of the tunnel transition section shape and steel bars based on BIM, a large amount of modeling work of designers can be liberated, all the repetitive and cumbersome work can be automated, and the three-dimensional BIM model of the tunnel transition section shape and steel bars can be automatically generated, greatly improving the efficiency of project design and providing a complete, effective, convenient and fast method for designers to design the tunnel transition section shape and steel bars. Description of the Drawings

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a step flow chart of a parametric modeling method for the shape and steel bars of a tunnel transition section based on BIM provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the shape model of the tunnel transition section obtained by parametric modeling lofting provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the steel bar model of the tunnel transition section obtained by parametric modeling lofting provided by the embodiment of the present invention; Figure 4 It is the three-view drawing of the three-dimensional BIM model of the single-layer steel bars in the tunnel transition section provided by the embodiment of the present invention; Figure 5 It is a schematic diagram of the three-dimensional BIM model of the shape and steel bars of the tunnel transition section provided by the embodiment of the present invention. Detailed implementation manners

[0022] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope protected by the present invention.

[0023] In water conservancy and hydropower projects, except for the conventional graphics at the head and tail ends, the shapes of other parts of the tunnel transition section are basically special curves without control equations, and can only be approximately fitted by spline curves. Usually, for the steel bar drawing of the transition section, only the cross-sectional steel bar drawings at the head and tail ends can be given in the design to approximately indicate the general positions of the steel bars. During construction, due to the lack of refinement in design, it highly depends on the experience of on-site construction for erecting and binding the steel bars, relying heavily on manual experience and with low work efficiency. In order to accurately locate and indicate the preparation positions and other dimensional information of each steel bar in the transition section, this application proposes a parametric modeling method for the shape and steel bars of the tunnel transition section based on BIM. By automatically generating a three-dimensional model and optimizing the design process, the design efficiency and accuracy can be effectively improved.

[0024] Figure 1 It is a step flow chart of a parametric modeling method for the shape and steel bars of the tunnel transition section based on BIM provided by the embodiment of the present invention. Refer to Figure 1 The present invention provides a parametric modeling method for the shape and steel bars of the tunnel transition section based on BIM, including the following steps: S1: Obtain the geometric information of the upstream and downstream of the tunnel transition section and the upstream-downstream distance respectively; In some embodiments, the geometric information includes shape, side length, and diameter.

[0025] Exemplarily, the upstream of the transition section is a rectangle, and the downstream is a closed curve, including a circle, an ellipse, and a symmetric parabola. It can be obtained by parametric modeling according to the geometric graphics, the scheme model, or according to the architectural design drawings through the geometric boundary dimensions of the drawings, as Figure 2 described.

[0026] S2: Based on the geometric information, divide the upstream and downstream of the tunnel transition section respectively, and obtain the shape of the tunnel transition section through lofting operation. In some embodiments, the step of dividing the upstream and downstream of the tunnel transition section respectively based on the geometric information and obtaining the shape of the tunnel transition section through lofting operation specifically includes: S21: Based on the geometric information of the upstream of the tunnel transition section, decompose, project the upstream of the tunnel transition section, and perform a lofting operation to obtain a first connection surface. In some embodiments, the step of decomposing, projecting the upstream of the tunnel transition section based on the geometric information of the upstream of the tunnel transition section and performing a lofting operation to obtain a first connection surface includes the following steps: Based on the shape and side length in the geometric information of the upstream of the tunnel transition section, divide the upstream shape into N upstream line segments in some embodiments, and determine the midpoint of each upstream line segment.

[0027] By the minimum distance projection method, map the midpoints of each of the upstream line segments to the downstream respectively, and generate corresponding upstream projection points. Perform a lofting operation based on the midpoints of each of the upstream line segments and their corresponding upstream projection points to obtain the first connection surface.

[0028] Exemplarily, decompose the upstream rectangular polyline of the tunnel transition section into 4 independent upstream line segments, and extract the midpoints of each upstream line segment (4 in total).

[0029] By the minimum distance projection method, map the midpoints of the 4 upstream line segments to the downstream closed curve, and generate 4 corresponding upstream projection points.

[0030] Based on the 4 independent upstream line segments and the 4 corresponding upstream projection points, perform a Loft operation to generate 4 first connection surfaces.

[0031] S22: Based on the geometric information of the downstream of the tunnel transition section, decompose, reverse-project the downstream of the tunnel transition section, and perform a lofting operation to obtain a second connection surface. In some embodiments, the step of decomposing, reverse-projecting the downstream of the tunnel transition section based on the geometric information of the downstream of the tunnel transition section and performing a lofting operation to obtain a second connection surface includes the following steps: Based on the shape and side length in the geometric information of the downstream of the tunnel transition section, divide the downstream shape into M downstream line segments in some embodiments, and determine the midpoint of each downstream line segment; M and N are in an integer multiple relationship; the integer M can be a multiple of the integer N, and the integer N can also be a multiple of the integer M; on the basis of ensuring that M and N are in an integer multiple relationship, the larger the values of the two, the smoother the surface of the transition section.

[0032] By means of the minimum distance projection method, the midpoints of each of the downstream line segments are respectively mapped upstream to generate corresponding downstream projection points. Based on the midpoints of each of the downstream line segments and their corresponding downstream projection points, a lofting operation is performed to obtain the second connecting surface.

[0033] Exemplarily, the downstream closed curve of the tunnel transition section is cut into 4 downstream line segments along the XY axis, and the midpoints of each downstream line segment (a total of 4) are extracted.

[0034] The midpoints of the downstream line segments are inversely projected upstream to the upstream rectangular polyline to generate 4 downstream projection points.

[0035] Based on the 4 downstream line segments and the 4 downstream projection points, 4 second connecting surfaces are generated again by lofting.

[0036] S23: According to the upstream surface of the tunnel transition section, the downstream surface of the tunnel transition section, the first connecting surface, and the second connecting surface, an inner contour solid of the tunnel transition section is formed. In some embodiments, the forming of the inner contour solid of the tunnel transition section according to the upstream surface of the tunnel transition section, the downstream surface of the tunnel transition section, the first connecting surface, and the second connecting surface is specifically as follows: Based on the geometric information of the upstream of the tunnel transition section, a transformation is performed to obtain the upstream surface of the tunnel transition section. Based on the geometric information of the downstream of the tunnel transition section, a transformation is performed to obtain the downstream surface of the tunnel transition section. The upstream surface of the tunnel transition section, the downstream surface of the tunnel transition section, the first connecting surface, and the second connecting surface are merged to obtain the inner contour solid of the tunnel transition section.

[0037] S24: Based on the geometric information of the upstream of the tunnel transition section and the geometric information of the downstream of the tunnel transition section, a preset distance is offset outward respectively to obtain the outer contour geometric information of the upstream of the tunnel transition section and the outer contour geometric information of the downstream of the tunnel transition section. S25: According to the outer contour geometric information of the upstream of the tunnel transition section and the outer contour geometric information of the downstream of the tunnel transition section, the upstream and downstream of the tunnel transition section are respectively segmented, and through a lofting operation, an outer contour solid of the tunnel transition section is obtained; specifically the same as steps S21 - S23.

[0038] Exemplarily, Contour offset: The upstream rectangle and the downstream closed curve, that is, the geometric information of the upstream of the tunnel transition section and the geometric information of the downstream of the tunnel transition section, are offset (Offset) outward by a preset distance (which can be the thickness of the concrete lining) to generate new outer contour boundaries, that is, the outer contour geometric information of the upstream of the tunnel transition section and the outer contour geometric information of the downstream of the tunnel transition section.

[0039] Repeated inner contour generation logic: For the offset outer contour boundary, generate the outer contour entity of the tunnel transition section according to the decomposition, projection, and lofting processes of the inner contour.

[0040] S26: Determine the shape of the tunnel transition section based on the inner contour entity and the outer contour entity of the tunnel transition section.

[0041] In some embodiments, the determining the shape of the tunnel transition section based on the inner contour entity and the outer contour entity of the tunnel transition section is as follows: Based on the inner contour entity and the outer contour entity of the tunnel transition section, obtain the shape of the tunnel transition section through Boolean subtraction operation.

[0042] Exemplarily, construct a BIM model according to the shape of the tunnel transition section, and generate three-dimensional models of the inner and outer surfaces of the tunnel transition section in BIM software. Through Boolean operation, fill the space between the inner and outer surfaces to generate a complete three-dimensional BIM model of the concrete shape of the tunnel transition section. This model contains the shape and thickness information of the tunnel. The system can also automatically calculate the concrete volume and corresponding engineering quantity data of the tunnel transition section based on the three-dimensional model. Generate a bill of quantities for concrete based on these data and provide it to the construction unit as a reference for material budgeting and procurement.

[0043] S3: According to the steel bar layout parameters, determine the layout positions of the steel bars in the shape of the tunnel transition section and complete the modeling through BIM.

[0044] BIM modeling (Building Information Modeling) is a building life cycle management method based on digital technology. Its core lies in integrating multi-dimensional information such as geometric information, physical properties, time schedule, cost data, and operation and maintenance management of a building project through a three-dimensional visualization model to form a dynamic collaborative data platform. Different from traditional two-dimensional drawings or single three-dimensional modeling, BIM modeling not only presents the spatial structure but also can associate details such as material specifications, construction processes, and energy consumption simulation, realizing seamless information connection in the design, construction, and operation stages. In this application, according to the steel bar layout parameters, determine the layout positions of the steel bars in the shape of the tunnel transition section and complete the modeling through BIM.

[0045] In some embodiments, the determining the layout positions of the steel bars in the shape of the tunnel transition section according to the steel bar layout parameters includes: S31: Obtain the steel bar layout parameters, including the thickness of the steel bar protection layer, the diameter and spacing of the stressed steel bars, and the diameter and spacing of the distribution steel bars; Exemplarily, the steel bar layout parameters can be obtained through finite element analysis according to the tunnel transition section shape obtained previously, and these parameters serve as the basis for generating the subsequent steel bar layout model. The method of obtaining the steel bar layout parameters through finite element analysis is an existing method, and will not be elaborated in this application.

[0046] In some embodiments, according to the tunnel transition section shape, tunnel water pressure, and tunnel surrounding rock parameter information, the steel bar layout parameters are obtained through finite element analysis.

[0047] Although the finite element analysis method also has a modeling function and can construct the tunnel transition section shape according to the relevant upstream and downstream parameters, the geometric modeling tools of finite element software are far from flexible enough to handle complex curved surfaces or special-shaped structures, and are mostly "static models". If the dimensions need to be adjusted, re-modeling is required, and the iteration efficiency is low. Based on this, in this application, through S2, the tunnel transition section shape is first constructed, and then the finite element analysis method is used to obtain the steel bar layout parameters, further improving the accuracy of the design results of the transition section.

[0048] S32: Determine the positioning line of the stress-bearing steel bars according to the steel bar cover thickness, diameter, and spacing of the stress-bearing steel bars; In some embodiments, the method for determining the positioning line of the stress-bearing steel bars according to the steel bar cover thickness, diameter, and spacing of the stress-bearing steel bars includes the following steps: According to the diameter and spacing of the stress-bearing steel bars, the inner contour and outer contour of the tunnel transition section shape are horizontally divided respectively to obtain the inner contour reference line and outer contour reference line of the stress-bearing steel bars; these reference lines are used to determine the steel bar layout area. The horizontal direction is perpendicular to the tunnel extension direction; According to the steel bar cover thickness and the diameter of the stress-bearing steel bars, the inner contour reference line of the stress-bearing steel bars is offset inward, and the outer contour reference line of the stress-bearing steel bars is offset outward to determine the positioning line of the stress-bearing steel bars.

[0049] S33: Determine the positioning line of the distribution steel bars according to the diameter and spacing of the distribution steel bars; Exemplarily, according to the positioning line of the distribution steel bars, a lofting operation is used to generate a 3D BIM model of the stress-bearing steel bars. See Figure 3 The horizontal steel bars in are the stress-bearing steel bars.

[0050] In some embodiments, the method for determining the positioning line of the distribution steel bars according to the diameter and spacing of the distribution steel bars includes the following steps: According to the spacing of the distribution steel bars, the positioning line of the stress-bearing steel bars is segmented; At the segmentation points of the positioning line of the stress-bearing steel bars, an offset is made according to the diameter of the distribution steel bars, and then along the tunnel direction, the positioning line of the distribution steel bars is determined.

[0051] Exemplarily, when offsetting according to the diameter of the distribution steel bars, the offset distance is at least the sum of the diameters of the distribution steel bars and the stress-bearing steel bars, so as to avoid the intersection of the stress-bearing steel bars and the distribution steel bars and keep them in separate layers. Of course, considering the bearing capacity, multiple layers of stress-bearing and distribution steel bars may also be set, and offset inwards and outwards on the basis of the existing design. Exemplarily, according to the positioning line of the distribution steel bars, through the lofting operation of the diameter circle of the distribution steel bars, a three-dimensional BIM model of the distribution steel bars in the transition section of the tunnel is generated, such as Figure 2 The steel bars arranged perpendicular to the stress-bearing steel bars in Figure 2 are distribution steel bars.

[0052] S34: Determine the layout position of the steel bars according to the stress-bearing steel bar positioning line and the distribution steel bar positioning line.

[0053] The final distribution steel bars are obtained by simplifying the stress-bearing steel bars through calculating the turning angle In some embodiments, after determining the stress-bearing steel bar positioning line and the distribution steel bar positioning line in S34, it further includes: Respectively, according to each positioning line segment in the stress-bearing steel bar positioning line and the distribution steel bar positioning line, by calculating the turning angle, obtain the simplified stress-bearing steel bar positioning line and the simplified distribution steel bar positioning line; Determine the layout position of the steel bars with the simplified stress-bearing steel bar positioning line and the simplified distribution steel bar positioning line.

[0054] Exemplarily, taking the stress-bearing steel bars as an example: 1. Cut the stress-bearing steel bar positioning line into multiple line segments, and then traverse all the line segments: check every two adjacent line segments and calculate the included angle between them.

[0055] 2. Judge whether the included angle is less than the allowable value: if the angle is less than the preset threshold (such as 5 degrees), then consider merging.

[0056] 3. Merge the line segments: Merge these two line segments that meet the angle threshold into a straight line segment. It is necessary to calculate the new starting point and ending point so that the merged line segment can approximately replace the original two line segments.

[0057] 4. Check the error after merging: Whether the maximum distance between the merged line segment and the original two line segments is within the allowable error range. If it exceeds, the merging needs to be abandoned.

[0058] 5. Repeat this process: Multiple iterations may be required until there are no more line segments to merge.

[0059] The stress-bearing steel bar positioning line and the distribution steel bar positioning line are smooth curves. However, in actual construction, steel bars are usually straight. To facilitate the processing of steel bars, the above method can be used to simplify the stress-bearing steel bar positioning line and the distribution steel bar positioning line. Using the simplified stress-bearing steel bar positioning line and the simplified distribution steel bar positioning line to process steel bars can not only maximize the conformity to the shape of the gradually changing section of the tunnel, but also simplify the steel bar processing and construction difficulty.

[0060] After the steel bar model is generated, the system automatically calculates the corresponding steel bar engineering quantity according to the quantity and specifications of the arranged steel bars, and generates a steel bar engineering quantity list. This list includes the required steel bar types, diameters, lengths, and weights, which is convenient for project budgeting and material procurement, as shown in Table 1. This application can achieve a variety of different scheme models and their corresponding engineering quantity lists by modifying parameters such as the geometric information of the upstream and downstream of the gradually changing section of the tunnel, the upstream and downstream distances, and the concrete lining thickness, greatly improving the modeling efficiency and work efficiency. Table 1 Steel Bar Engineering Quantity List

[0061] In this embodiment, the computer of the parametric modeling program completes the generation work of the BIM-based shape and steel bar parametric modeling of the gradually changing section of the tunnel, and generates a three-dimensional BIM model of the shape and steel bars of the gradually changing section of the tunnel. Figure 4 It is the three-view drawing of the three-dimensional BIM model of the single-layer steel bars of the gradually changing section of the tunnel provided by the embodiment of the present invention. Figure 5 It is a schematic diagram of the three-dimensional BIM model of the shape and steel bars of the gradually changing section of the tunnel provided by the embodiment of the present invention.

[0062] The BIM-based method for parametric modeling of the shape and steel bars of the gradually changing section of the tunnel provided by this application first conducts the modeling of the shape of the gradually changing section of the tunnel, then determines the steel bar parameter information of the model through the processing of the model, and then conducts the steel bar modeling of the gradually changing section of the tunnel to ensure the structural safety of the model. Through this BIM-based parametric modeling of the shape and steel bars of the gradually changing section of the tunnel, a large amount of modeling work of designers can be liberated, all the repetitive and cumbersome work can be automated, and a three-dimensional BIM model of the shape and steel bars of the gradually changing section of the tunnel can be automatically generated, greatly improving the project design efficiency. Through this method, by modifying the basic parameters such as the geometric information of the upstream and downstream of the gradually changing section of the tunnel, the upstream and downstream distances, and the concrete lining thickness, a variety of different scheme models and their corresponding material lists can be realized, providing a complete, effective, convenient, and fast method for designers to design the shape and steel bars of the gradually changing section of the tunnel, and greatly improving the modeling accuracy and design efficiency of designers.

[0063] 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; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A BIM-based tunnel transition section body shape and reinforcement parameter modeling method, characterized in that: The steps include: Obtain the geometric information of the upstream and downstream of the tunnel transition section and the upstream and downstream distances respectively; Based on the geometric information, the upstream and downstream of the tunnel transition section are segmented respectively, and the shape of the tunnel transition section is obtained through lofting operation; According to the steel bar layout parameters, the layout position of the steel bars is determined in the gradual section of the tunnel, and the modeling is completed through BIM.

2. According to a BIM-based parametric modeling method for tunnel transition section shape and reinforcement according to claim 1, it is characterized in that: The reinforcement layout parameters are obtained through finite element analysis method according to the shape of the tunnel transition section, the tunnel water pressure and the tunnel surrounding rock parameter information.

3. According to a BIM-based tunnel transition section body shape and reinforcement parameter modeling method according to claim 1, it is characterized in that: Based on the geometric information, the upstream and downstream of the tunnel transition section are segmented respectively, and the shape of the tunnel transition section is obtained through a lofting operation, which specifically includes: Based on the geometric information of the upstream of the tunnel transition section, the upstream of the tunnel transition section is decomposed, projected, and lofted to obtain a first connecting surface; Based on the geometric information of the downstream of the tunnel transition section, the downstream of the tunnel transition section is decomposed, reversely projected, and lofted to obtain a second connecting surface; According to the upstream curved surface of the tunnel transition section, the downstream curved surface of the tunnel transition section, the first connecting curved surface and the second connecting curved surface, a tunnel transition section inner contour entity is formed; Based on the geometric information of the upstream of the tunnel gradient section and the geometric information of the downstream of the tunnel gradient section, the outer contour geometric information of the upstream of the tunnel gradient section and the outer contour geometric information of the downstream of the tunnel gradient section are respectively offset outward by a preset distance to obtain the outer contour geometric information of the upstream of the tunnel gradient section and the outer contour geometric information of the downstream of the tunnel gradient section; According to the outer contour geometric information of the upstream of the tunnel gradient section and the outer contour geometric information of the downstream of the tunnel gradient section, the upstream and downstream of the tunnel gradient section are segmented respectively, and the outer contour entity of the tunnel gradient section is obtained through lofting operation; The shape of the tunnel transition section is determined according to the inner contour entity of the tunnel transition section and the outer contour entity of the tunnel transition section.

4. According to the BIM-based parameterized modeling method of tunnel transition section shape and reinforcement according to claim 3, it is characterized in that: Based on the geometric information of the upstream of the tunnel transition section, the upstream of the tunnel transition section is decomposed, projected, and lofted to obtain a first connecting surface, including the following steps: Based on the shape and side length in the geometric information of the upstream of the tunnel transition section, segment the upstream shape into N upstream line segments in some embodiments, and determine the midpoint of each upstream line segment; By using the minimum distance projection method, the midpoints of each upstream line segment are respectively mapped to the downstream, and the corresponding upstream projection points are respectively generated; A lofting operation is performed according to the midpoint of each upstream line segment and its corresponding upstream projection point to obtain the first connecting surface.

5. According to the BIM-based parameterized modeling method of tunnel transition section shape and reinforcement according to claim 4, it is characterized in that: Based on the geometric information of the downstream of the tunnel gradient section, the downstream of the tunnel gradient section is decomposed, reversely projected, and lofted to obtain a second connecting surface, including the following steps: Based on the shape and side length in the geometric information of the downstream of the tunnel gradient section, the downstream shape is divided into M downstream line segments in some embodiments, and the midpoint of each downstream line segment is determined; wherein M and N are integer multiples; By using the minimum distance projection method, the midpoints of the downstream line segments are respectively mapped to the upstream, and corresponding downstream projection points are generated respectively; A lofting operation is performed according to the midpoint of each of the downstream line segments and its corresponding downstream projection point to obtain the second connecting surface.

6. The BIM-based parameterized modeling method for tunnel transition section shape and reinforcement according to claim 5 is characterized in that: The forming of the inner contour entity of the tunnel transition section according to the upstream curved surface of the tunnel transition section, the downstream curved surface of the tunnel transition section, the first connecting curved surface and the second connecting curved surface is specifically: Based on the geometric information of the upstream of the tunnel transition section, a transformation is performed to obtain the upstream curved surface of the tunnel transition section; Based on the geometric information of the downstream of the tunnel transition section, a transformation is performed to obtain a curved surface downstream of the tunnel transition section; The upstream curved surface of the tunnel transition section, the downstream curved surface of the tunnel transition section, the first connecting curved surface and the second connecting curved surface are combined to obtain an inner contour entity of the tunnel transition section.

7. The BIM-based parametric modeling method for tunnel transition section shape and reinforcement according to claim 1 is characterized in that: Determining the layout position of the steel bars in the tunnel transition section according to the steel bar layout parameters includes: Obtain reinforcement layout parameters, including reinforcement cover thickness, stress reinforcement diameter and spacing, and distribution reinforcement diameter and spacing; Determine the location line of the stressed steel bars according to the thickness of the steel bar protection layer, the diameter and spacing of the stressed steel bars; Determine the distribution steel bar positioning line based on the diameter and spacing of the distribution steel bars; The layout position of the steel bars is determined according to the stressed steel bar positioning line and the distributed steel bar positioning line.

8. The BIM-based parametric modeling method for tunnel transition section shape and reinforcement according to claim 7 is characterized in that: The method of determining the stress-bearing steel bar positioning line based on the thickness of the steel bar protective layer, the diameter and spacing of the stress-bearing steel bars includes the following methods: According to the spacing of the stressed steel bars, the inner contour and the outer contour of the gradual section of the tunnel are transversely divided to obtain the inner contour reference line and the outer contour reference line of the stressed steel bars; the transverse direction is perpendicular to the extension direction of the tunnel; According to the thickness of the steel bar protective layer and the diameter of the stressed steel bar, the inner contour reference line of the stressed steel bar is offset inward, and the outer contour reference line of the stressed steel bar is offset outward to determine the stressed steel bar positioning line.

9. The BIM-based tunnel transition section body shape and reinforcement parameter modeling method according to claim 7 is characterized in that: The method of determining the distribution steel bar positioning line based on the diameter and spacing of the distribution steel bars includes the following methods: According to the spacing of the distribution steel bars, the stress-bearing steel bar positioning line is divided; At the division point of the stressed reinforcement positioning line, an offset is made according to the diameter of the distribution reinforcement, and then the distribution reinforcement positioning line is determined along the tunnel direction.

10. The BIM-based parametric modeling method for tunnel transition section shape and reinforcement according to claim 7, characterized in that: After determining the stress reinforcement location line and the distribution reinforcement location line, the method further includes: According to each positioning line segment in the stressed steel bar positioning line and the distributed steel bar positioning line, respectively, by calculating the turning angle, a simplified stressed steel bar positioning line and a simplified distributed steel bar positioning line are obtained; The layout position of the steel bars is determined by using the simplified stress-bearing steel bar positioning line and the simplified distribution steel bar positioning line.

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