BIM (Building Information Modeling)-based parametric modeling and mapping method for simply-supported U-shaped aqueduct structure

Abstract

The invention discloses a BIM (Building Information Modeling)-based parametric modeling and mapping method for a simply-supported U-shaped aqueduct structure in the technical field of three-dimensional modeling of water conservancy projects, which mainly comprises the following steps of: on the basis of a traditional BIM modeling technology, parameterizing basic physical units such as points, lines, surfaces and bodies of the aqueduct structure; the method comprises the following steps: establishing a parameterized construction model, a pre-stressed steel beam model and a reinforcing steel bar model, checking structural arrangement, steel beam arrangement and reinforcing steel bar arrangement from a three-dimensional angle, checking a relative position relationship among the three parts, then establishing a section cutting plane to form a section map, arranging the drawing according to a specified sequence by utilizing functions of front view, side view, sectioning and the like, and constructing a pre-stressed steel beam model and a reinforcing steel bar model. And a technical rule with an automatic mapping function is formed. When aqueduct structures of the same type and different sizes are modeled subsequently, modeling and drawing of the aqueduct can be completed only by modifying corresponding parameters, design work is greatly facilitated, the method can be matched with a construction side to simplify the design difficulty of construction measures, and therefore forward design of the aqueduct is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of three-dimensional modeling of water conservancy projects, and in particular to a parameterized modeling and mapping method for simply supported U-shaped aqueduct structures based on BIM. BACKGROUND

[0002] Building Information Modeling (BIM) is a digital technology-based building information management method aimed at achieving full life cycle information integration and sharing from design, construction to operation and maintenance by creating and managing three-dimensional models of building projects. In recent years, BIM technology has gradually been adopted in water conservancy construction, but its application in water conservancy engineering is still shallow, especially for prestressed concrete aqueduct structures, which are usually only designed in three dimensions and viewed in appearance, without forming specific modeling techniques. It is difficult to achieve forward design of aqueducts with a wide variety of reinforcing bars.

[0003] Simply supported U-shaped aqueducts are a kind of spatial long-shell thin-walled aqueduct structures with excellent stress, good hydraulic conditions, and small engineering quantities, and therefore are widely used. The current three-dimensional mapping method for aqueducts is a general mapping method for concrete structures, which is universal but has the following shortcomings when drawing such specific spatial thin-walled long-shell structures: (1) It can only be drawn according to the general mapping method for concrete structures, which is time-consuming; (2) It cannot be drawn together with prestressed steel beams, and additional drawings of prestressed steel beams are needed later; (3) The design file often needs to be modified repeatedly, and the front view, side view and sectional view cannot be updated after drawing.

[0004] Therefore, it is necessary to develop an aqueduct modeling and mapping method that is more efficient and conducive to forward design. SUMMARY

[0005] To overcome the shortcomings of the existing mapping method for concrete structures, such as large amount of drawing work, inability to display prestressed steel beams, and inability to update drawings, the technical problem to be solved by the present application is to provide a parameterized modeling and mapping method for simply supported U-shaped aqueduct structures based on BIM, which can improve drawing efficiency and facilitate modification.

[0006] The technical solution adopted by the present application to solve its technical problem is: The parameterized modeling and mapping method for simply supported U-shaped aqueduct structures based on BIM comprises the following steps: S1, determining the size that meets the hydraulic conditions of the aqueduct according to the engineering requirements, including the longitudinal and transverse dimensions of the aqueduct body, as well as the positions and types of prestressed steel beams and reinforcing bars; S2, a local coordinate system is established at the position corresponding to the change of the groove body section in the main coordinate system, and all local coordinate systems are consistent with the direction of the main coordinate system; S3, according to the size data of the aqueduct, first draw a sketch on the section perpendicular to the longitudinal direction of the groove body at the position of the established local coordinate system, and parameterize the shape and size parameters on the section to obtain the transverse parameters, then obtain the longitudinal parameters according to the position of the change of the groove body section, and finally establish a three-dimensional construction model template in the BIM software according to the transverse parameters and the longitudinal parameters; S4, the coordinates of the starting point and the ending point of the steel beam are established in the two local coordinate systems of the starting point and the ending point of the steel beam, and are connected into a straight line to establish a longitudinal prestressed steel beam line, and the establishment of the longitudinal prestressed steel beam is sequentially completed to form a longitudinal prestressed steel beam group, and the longitudinal prestressed steel beam is given a number and a diameter attribute; the inner wall water-facing surface is offset to the outside normal of the groove body to obtain an offset surface, and a plane perpendicular to the center line of the aqueduct intersects with the offset surface to obtain the shape of the ring-shaped prestressed steel strand, and the two ends are extended upward by a distance to generate a ring-shaped prestressed steel beam, the ring-shaped prestressed steel beam is moved and copied on the offset surface along the length direction of the groove body to obtain a ring-shaped prestressed steel beam group, and the ring-shaped prestressed steel beam is given a number and a diameter attribute; a parameterized prestressed steel beam model template is established according to the longitudinal and ring-shaped prestressed steel beam groups; S5, select a surface or a surface group composed of several surfaces of the three-dimensional construction model template, set the thickness of the protective layer c, the diameter of the first layer of steel bars close to the surface is d1, and the diameter of the second layer of steel bars is d2; the selected surface or surface group is offset inward along its normal direction by c+0.5d1 to obtain a first offset surface, a plane perpendicular to the first offset surface intersects with it to obtain the preliminary shape of the ring-shaped steel bar, and the two ends are extended upward by a distance and hooked to generate a ring-shaped steel bar, the ring-shaped steel bar is moved and copied on the first offset surface to obtain a ring-shaped steel bar group, and the ring-shaped steel bar is given a model number and a diameter attribute; the selected surface or surface group is offset inward along its normal direction by c+d1+0.5d2 to obtain a second offset surface, a horizontal plane intersects with the second offset surface to obtain the preliminary shape of the longitudinal steel bar, and the longitudinal steel bar is moved and copied on the offset surface along its tangential direction to obtain a longitudinal steel bar group, and the longitudinal steel bar is given a model number and a diameter attribute; a parameterized steel bar model template is established according to the longitudinal and ring-shaped steel bar groups; S6, select the position of the groove body that needs to be cut, and obtain a parameterized cutting surface by establishing the coordinates of four points of the cutting surface in the local coordinate system; S7, according to the drawing program of the BIM software, three-dimensional construction model template, prestressed steel model template and steel model template are called in turn, meanwhile, according to the longitudinal dimension, transverse dimension, position and type of prestressed steel and steel determined in S1, each parameter is input into the corresponding template, the three-dimensional construction drawing of the aqueduct is generated, then the sectioning program of the software is called, the sectioning surface parameter is input, the body layout drawing, prestressed steel layout drawing and steel layout drawing are generated.

[0007] Further, the transverse parameters include: inner side gang hance width B1, standard section wall thickness B2, standard section outer side gang hance width B3, standard section outer side straight wall section height H1, water-facing inner wall straight wall section height H2, gang hance height H3, pull rod height H4, water-facing surface circular arc radius R0, body outer wall circular arc radius R1, standard section bottom thickening zone height H0, standard section bottom surface length L1, end rib bottom thickening zone height H5, end rib outer side straight wall section height H6, end rib bottom length L2, water stop groove width B4.

[0008] Further, the longitudinal parameters include: total length of the body W1, gradual change section length W2, end rib length W3, post-cast strip length W4, water stop groove length W5, pull rod width W6, pull rod spacing W7, whether to set the pull rod at the midspan position.

[0009] Further, when the three-dimensional model template is constructed by the BIM software in S3, the following steps are included: S31, by the plane generation instruction, the aqueduct starting point plane, the water stop groove ending plane, the post-cast strip division plane, the gradual change section starting plane, the gradual change section ending plane and the midspan plane are established according to the longitudinal parameters; S32, by the sketch instruction, the aqueduct end rib sketch and the aqueduct end rib water stop groove sketch are drawn on the aqueduct starting point plane, the gradual change section sketch is drawn on the gradual change section starting plane, and the standard section sketch is drawn on the gradual change section ending plane; S33, by the stretch command, the end rib sketch and the standard section sketch are stretched to generate the end rib model and the standard section model, the end rib model is stretched to the gradual change section starting plane, the standard section model is stretched to the midspan plane, the gradual change section sketch and the standard section sketch are connected by the multi-section envelope body command to generate the gradual change section model; S34, by the sketch command, the pull rod section sketch is drawn on the midspan plane, by the stretch command, the center position pull rod model is generated, by the formula setting, when the parameter of whether to set the pull rod at the midspan position is 1, the pull rod is located at the midspan, and when the parameter is 0, the center of the pull rod is W7 / 2 distance away from the midspan plane, in the formula setting, the total length of the body W1 is applied, by the array command, according to the pull rod spacing parameter, the pull rod model is arrayed to obtain the center pull rod and the end pull rod; S35, the end rib model, the transition section model, the standard section model, the center pull rod and the end pull rod are integrated into a whole half span model by adding command; S36, first, the water stop groove model is established by stretching the water stop groove sketch through the stretching command, and then the water stop groove is subtracted from the whole half span model through the subtracting command; S37, the end ring two-stage sealing anchor concrete sketch is drawn at the starting point plane of the aqueduct, the intermediate ring two-stage sealing anchor concrete sketch is drawn at the mid-span section, the end ring two-stage sealing anchor concrete sketch and the intermediate ring two-stage sealing anchor concrete sketch are stretched through the stretching command to establish the end ring two-stage sealing anchor concrete model and the half-span intermediate ring two-stage sealing anchor concrete model, the end ring two-stage sealing anchor concrete model and the half-span intermediate ring two-stage sealing anchor concrete model are subtracted from the whole half span model through the subtracting command to obtain the concrete half span model, and then the concrete half span model is divided into the post-cast strip model and the first-stage concrete half span model through the dividing command; S38, the post-cast strip model, the first-stage concrete half span model and the ring two-stage sealing anchor concrete model are mirrored through the mid-span plane through the mirroring command, and then the two half span models are integrated into the concrete model through the adding command, and the two half-span intermediate ring two-stage sealing anchor concrete models are combined into the intermediate ring two-stage sealing anchor concrete model, thus completing the establishment of the construction model template.

[0010] Further, in S4, when the pre-stressed steel bar model template is established by BIM software, the following steps are included: the steel bar model is established by RebarSmart, the interval first segment distance, interval end distance, steel bar spacing, steel bar extension, steel bar type and steel bar diameter are set through the fixed distance reinforcement function after the reinforcement plane and the reinforcement guide line are selected, and the steel bar is generated.

[0011] Further, in S5, the steel bar model template is established by RebarSmart, the interval first segment distance, interval end distance, steel bar extension and hook, steel bar type and steel bar diameter are set through the fixed distance reinforcement function after the reinforcement plane and the reinforcement guide line are selected, and the steel bar is generated.

[0012] Further, in S4 and S5, when the pre-stressed steel bar and the steel bar are extended and bent, the point positions of each line segment are calculated according to the following principles: S51. The initial straight line segment AB, the starting point coordinates are , and the end point coordinates are , The direction vector of AB is obtained , wherein ; S52. The first extension BC, the extension length L1, the end point is obtained; S53. The hook needs to be generated in a plane perpendicular to the straight line, and the normal direction vector of the hook plane is selected ; S54. The center of the hook is calculated, ; S55. The hook is generated, and the parametric equation of the hook is: , the end point of the hook , and are two unit vectors perpendicular to each other in the hook plane; wherein the center is O, the radius is R, the starting angle is 0°, the ending angle is α, and β represents the rotation angle of the point on the circular arc relative to the starting edge; S56. The direction vector of the hook after being extended twice , the extension distance L2, and the extension end point .

[0013] Further, in S7, when the slot body arrangement drawing, the prestressed steel beam arrangement drawing and the steel bar arrangement drawing are generated, the drawing layout is performed first, the drawing layout of the aqueduct is in turn the slot body construction drawing, the prestressed steel beam arrangement drawing and the steel bar arrangement drawing, the three types of drawings are arranged in turn according to the elevation arrangement and the cross-sectional arrangement, then the viewport layout is performed according to the required drawing size, each viewport layout is customized, the layout mode is to perform orthographic projection and planar projection on the model, or to cut the model to obtain the cut construction, finally the projection is dimensioned, the slot body quantity, the prestressed steel beam quantity and the steel bar quantity are counted by the engineering quantity table, then the printing parameters can be designed, and the drawing is generated.

[0014] The beneficial effects of the present application are: by parameterizing the basic physical units such as points, lines, surfaces and bodies of the aqueduct structure on the basis of the traditional BIM modeling technology, the parametric construction model, the prestressed steel beam model and the steel bar model are established, the structure arrangement, the steel beam arrangement and the steel bar arrangement can be viewed from the three-dimensional perspective, and the relative positional relationship of the three is viewed;By establishing a cutting plane to form a sectional view, arranging the drawings in a specified order by using orthographic projection, side view and cutting, a technical rule with automatic drawing function is formed, for subsequent aqueduct structures of this type, only the parameters need to be modified, and the aqueduct modeling and drawing can be completed, which greatly facilitates the design work, and also realizes the forward design of such structures. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is the flowchart of the present application; Figure 2 is the front view of the three-dimensional construction model of the aqueduct; Figure 3 is the plan view of the three-dimensional construction model of the aqueduct; Figure 4is a side view of the three-dimensional configuration model of the aqueduct; Figure 5 is Figure 2 is a I-I sectional view; Figure 6 is a sectional view of the prestressed steel beam model; Figure 7 is a sectional view of the steel bar model; Figure 8 is a point position schematic diagram of the steel beam and steel bar extension and hook.

[0016] In the figure, 1 is an end rib model, 2 is a standard section model, 3 is a gradual change section model, 4 is a center pull rod, 5 is an end pull rod, 6 is a water stop groove model, 7 is an end ring two-stage sealing anchor concrete model, 8 is a half-span intermediate ring two-stage sealing anchor concrete model, 9 is a longitudinal prestressed steel beam, 10 is a ring prestressed steel beam, 11 is a longitudinal steel bar, 12 is a ring steel bar, and 13 is a longitudinal steel beam hole. DETAILED DESCRIPTION

[0017] The application will be further described below with reference to the accompanying drawings.

[0018] As Figure 1 shown, the parameterized modeling and mapping method for a simply supported U-shaped aqueduct structure based on BIM provided by the application mainly includes the following steps: S1. According to the engineering requirements, initially determine the aqueduct structure size, perform structure design and calculation by using the finite element method, and determine the size that meets the aqueduct hydraulics conditions, including the longitudinal and transverse sizes of the trough body, and the positions and types of the prestressed steel beam and steel bar; S2. Establish a local coordinate system in the main coordinate system corresponding to the position of the trough body cross section change, all local coordinate systems are consistent with the direction of the main coordinate system, the change of the length direction of the trough body can be directly positioned through the local coordinate system, the position of the local coordinate system is changed, and the length of the trough body is updated; S3. According to the size data of the aqueduct, first draw a sketch on the cross section perpendicular to the longitudinal direction of the trough body at the position of the established local coordinate system, that is, draw the shape of the cross section at each local coordinate system position, parameterize the shape size on the cross section to obtain a transverse parameter, then obtain a longitudinal parameter according to the position of the trough body cross section change, and finally establish a three-dimensional configuration model template in the BIM software according to the transverse parameter and the longitudinal parameter; S4, establish the coordinates of the starting point and the ending point of the steel tendon in two local coordinate systems at the starting point and the ending point of the steel tendon, connect them into a straight line, establish the longitudinal prestressed steel tendon line, sequentially complete the establishment of the longitudinal prestressed steel tendon, form the longitudinal prestressed steel tendon group, and give the longitudinal prestressed steel tendon a number and a diameter attribute; offset the inner wall water-facing surface to the outside normal of the tank body to obtain an offset surface, obtain the shape of the ring-shaped prestressed steel strand by intersecting a plane perpendicular to the center line of the aqueduct with the offset surface, and extend the two ends upward by a distance to generate the ring-shaped prestressed steel tendon, move and copy the ring-shaped prestressed steel tendon on the offset surface along the length direction of the tank body to obtain the ring-shaped prestressed steel tendon group, and give the ring-shaped prestressed steel tendon a number and a diameter attribute; establish a parameterized prestressed steel tendon model template according to the longitudinal and ring-shaped prestressed steel tendon groups; S5, select one surface or a surface combination of several surfaces of the three-dimensional construction model template to form a surface group, set the thickness of the protective layer as c, the diameter of the first layer of steel bars close to the surface is d1, and the diameter of the second layer of steel bars is d2; offset the selected surface or surface group inward along the normal direction thereof by c+0.5d1 to obtain a first offset surface, obtain the preliminary shape of the ring-shaped steel bar by intersecting a plane perpendicular to the first offset surface with the first offset surface, extend the two ends upward by a distance and bend hooks to generate the ring-shaped steel bar, move and copy the ring-shaped steel bar on the first offset surface to obtain the ring-shaped steel bar group, and give the ring-shaped steel bar a model number and a diameter attribute; offset the selected surface or surface group inward along the normal direction thereof by c+d1+0.5d2 to obtain a second offset surface, obtain the preliminary shape of the longitudinal steel bar by intersecting a horizontal plane with the second offset surface, move and copy the longitudinal steel bar on the offset surface along the tangential direction thereof to obtain the longitudinal steel bar group, and give the longitudinal steel bar a model number and a diameter attribute; establish a parameterized steel bar model template according to the longitudinal and ring-shaped steel bar groups; S6, select the position of the tank body that needs to be cut, and obtain a parameterized cutting surface by establishing the coordinates of four points of the cutting surface in a local coordinate system; S7, sequentially call the three-dimensional construction model template, the prestressed steel tendon model template and the steel bar model template according to the drawing program of the BIM software, simultaneously input various parameters into the corresponding templates according to the longitudinal size, the transverse size, the positions and the types of the prestressed steel tendon and the steel bar of the tank body determined in S1 to generate the three-dimensional construction drawing of the aqueduct, and then call the cutting program of the software, input the cutting surface parameters to generate the tank body layout drawing, the prestressed steel tendon layout drawing and the steel bar layout drawing.

[0019] The main idea of the application is to model an aqueduct with a certain span and section first, parameterize the model size, and then update the model by changing the parameters to obtain the models of aqueducts with other spans and sections. The size of the aqueduct is mainly composed of a transverse parameter and a longitudinal parameter, wherein the transverse parameter is, for example, Figure 4 、 Figure 5The longitudinal parameters are shown in the table below, including: inner side gangboard width B1, standard section wall thickness B2, standard section outer side gangboard width B3, standard section outer side straight wall section height H1, water-facing inner wall straight wall section height H2, gangboard height H3, pull rod height H4, water-facing arc radius R0, groove body outer wall arc radius R1, standard section bottom thickening zone height H0, standard section bottom surface length L1, end rib bottom thickening zone height H5, end rib outer side straight wall section height H6, end rib bottom length L2, water stop groove width B4. The longitudinal parameters are shown in the table below, including: total length of the groove W1, length of the transition section W2, length of the end rib W3, length of the post-cast strip W4, length of the water stop groove W5, width of the pull rod W6, distance between the pull rods W7, and whether the pull rod is arranged at the midspan position. Figure 2 、 Figure 3 The longitudinal parameters are shown in the table below, including: total length of the groove W1, length of the transition section W2, length of the end rib W3, length of the post-cast strip W4, length of the water stop groove W5, width of the pull rod W6, distance between the pull rods W7, and whether the pull rod is arranged at the midspan position.

[0020] Specifically, when constructing a three-dimensional model template through BIM software, as shown in Figures 2-5 the following steps can be performed: S31, by a plane generation instruction, establishing the starting plane of the aqueduct, the ending plane of the water stop groove, the post-cast strip division plane, the starting plane of the transition section, the ending plane of the transition section, and the midspan plane according to the longitudinal parameters; S32, by a sketch instruction, drawing the aqueduct end rib sketch and the aqueduct end rib water stop groove sketch on the starting plane of the aqueduct, drawing the transition section sketch on the starting plane of the transition section, and drawing the standard section sketch on the ending plane of the transition section; S33, by a stretch command, stretching the end rib sketch and the standard section sketch to generate the end rib model 1 and the standard section model 2, the end rib model 1 being stretched to the starting plane of the transition section, the standard section model 2 being stretched to the midspan plane, and by a multi-section envelope body command, connecting the transition section sketch and the standard section sketch to generate the transition section model 3; S34, by a sketch command, drawing the pull rod section sketch on the midspan plane, by a stretch command, generating the center position pull rod model, and by formula setting, when the parameter of “whether the pull rod is arranged at the midspan position” is 1, the pull rod is located at the midspan, and when the parameter is 0, the center of the pull rod is at a distance of W7 / 2 from the midspan plane, and in the formula setting, the total length of the groove W1 is applied, by an array command, arraying the pull rod model according to the distance between the pull rods to obtain the center pull rod 4 and the end pull rod 5; S35, by an add command, combining the end rib model 1, the transition section model 3, the standard section model 2, the center pull rod 4, and the end pull rod 5 into a whole half-span model; S36, first, by a stretch command, stretching the water stop groove sketch to establish the water stop groove model 6, and then, by a subtract command, subtracting the water stop groove model from the whole half-span model; S37, drawing a sketch of the end annular second-phase anchor concrete on the starting plane of the aqueduct, and drawing a sketch of the middle annular second-phase anchor concrete on the mid-span section, stretching the end annular second-phase anchor concrete sketch and the middle annular second-phase anchor concrete sketch using the stretch command, establishing an end annular second-phase anchor concrete model 7 and a half-span middle annular second-phase anchor concrete model 8, subtracting the end annular second-phase anchor concrete model 7 and the half-span middle annular second-phase anchor concrete model 8 from the overall half-span model using the subtract command to obtain a concrete half-span model, and then using the split command to split the concrete half-span model into a post-cast strip model and a first-phase concrete half-span model; S38. Use the mirror command to mirror the post-cast strip model, the first-phase concrete half-span model, and the end circumferential second-phase anchor concrete model 7 through the mid-span plane. Then use the add command to combine the two half-span models into a concrete model. Combine the middle circumferential second-phase anchor concrete model 8 of the two connected half-spans into the middle circumferential second-phase anchor concrete model. Thus, the construction model template is established.

[0021] When establishing a prestressed steel bundle model template through BIM software, you can follow the steps below: establish a steel bundle model through RebarSmart, and through the fixed-distance reinforcement function, first select the reinforcement plane, then select the reinforcement guide line, and finally set the interval start distance, interval end distance, steel bundle spacing, steel bundle extension, steel bundle model and steel bundle diameter to generate the steel bundle. When establishing a steel bar model template, use the same method as the prestressed steel bundle model, establish a steel bar model through RebarSmart, and through the fixed-distance reinforcement function, first select the reinforcement plane, then select the reinforcement guide line, and finally set the interval start distance, interval end distance, steel bar extension and bend hook, steel bar model and steel bar diameter to generate the steel bar. The final generated prestressed steel bundle model template and steel bar model template have the following cross-sectional views: Figure 6 、 Figure 7 shown.

[0022] Furthermore, when the prestressed tendons and reinforcements are extended and bent in S4 and S5, as shown in FIG. Figure 8 As shown, the position of each line segment is calculated according to the following principles: S51. Initial straight line segment AB, starting point coordinates are , the end point coordinates are , Get the direction vector of AB ,in ; S52. Extend BC for the first time, extend the length L1, and get the endpoint ; S53. The hook needs to be generated in a plane perpendicular to the line. Select the normal direction vector of the hook plane. ; S54. Calculate the center of the hook, ; S55. Generate the hook, the hook parameter equation is: , the end point of the hook , and are two unit vectors perpendicular to each other in the hook plane; wherein the center is O, the radius is R, the starting angle is 0°, the ending angle is α, and β represents the rotation angle of the point on the circular arc relative to the starting edge; S56. The direction vector after the secondary extension of the hook , the extension distance L2, and the extension end point .

[0023] After determining the coordinates of each point and the lengths of each line segment according to the above steps, the sketch can be drawn, and the prestressed steel and the steel bar can be generated.

[0024] When finally generating the trough body layout diagram, the prestressed steel layout diagram and the steel bar layout diagram, the existing program of the BIM software is called in sequence according to the following process. First, the drawing layout is performed, and the drawing layout of the aqueduct is in sequence of the trough body construction diagram, the prestressed steel layout diagram and the steel bar layout diagram. The three types of diagrams are arranged in sequence according to the elevation arrangement and the cross-sectional arrangement, and then the viewport layout is performed according to the required sheet size, each viewport layout is customized, and the layout mode is to perform the front projection and the top projection of the model, or to cut the model to obtain the cut construction. Finally, the projection is dimensioned, and the trough body quantity, the prestressed steel quantity and the steel bar quantity are counted by the engineering quantity table.

[0025] In order to facilitate the distinction between the prestressed steel and the steel bar, the steel bar can be hidden when generating the prestressed steel layout diagram, and the prestressed steel can be hidden when generating the steel bar layout diagram, so as to obtain the prestressed steel model cut view as shown in Figure 6 and the steel bar model cut view as shown in Figure 7 . As shown in Figure 6 , the steel bar closest to the cut surface in the hoop prestressed steel bar group parallel to the cut surface is projected onto the cut surface to generate the hoop prestressed steel bar 10; the longitudinal prestressed steel bar group intersecting the cut surface at a series of points on the cut surface is displayed as a solid point with a diameter attribute, that is, the longitudinal prestressed steel bar 9. As shown in Figure 7As shown, the steel bars in the ring group closest to the section plane are projected onto the section plane to generate the ring steel 12, and the longitudinal steel group intersects the section plane at a series of points, which are shown as solid points with diameter properties on the section plane, i.e. the longitudinal steel 11. In order to facilitate subsequent construction, the section points of the prestressed steel bundle are generally shown in the section drawing of the steel bar, and the longitudinal bundle duct 13 can be represented by a circular ring to represent the passage of the prestressed pipe.

[0026] After the drawing is completed, the printing parameters can be set according to the text content, line color, etc. The printing parameters mainly reflect the characteristics of primary and secondary, in the trough body structure drawing, the structure of the solid line is the thickened solid line; in the trough body steel bundle arrangement drawing, the steel bundle is the main object of representation, i.e. the steel bundle line and point are the thickened display objects, and the trough body structure does not need to be thickened; in the trough body steel bar arrangement drawing, the steel bar is the main object of representation, i.e. the steel bar line and point are the thickened display objects, and the trough body structure and steel bundle do not need to be thickened, so as to output the required drawing of the designer, which can export cad file or pdf file.

[0027] When subsequent structural adjustment is needed, the longitudinal and transverse parameters, as well as the type and diameter of the prestressed steel bundle and steel bar can be changed, and the model will be automatically updated according to the parameters. After updating, the current drawing command is used to update the front view, side view and section view, etc. to obtain the new version of the trough body structure drawing, prestressed steel bundle arrangement drawing and steel bar arrangement drawing, which greatly improves the design efficiency. In addition, after parameterizing the model, collaborative design can be realized. If different sizes of simply supported aqueduct structures appear, a aqueduct model can be established first, and the corresponding reinforcement is completed. By parameterizing and adjusting the structure model, the steel bar model is updated, and the reinforcement of another shape of aqueduct can be realized. The model is delivered to the construction party, which can directly use the three-dimensional model to design the construction scheme, greatly simplifying the complexity and difficulty of construction measure design.

Claims

1. A method for parametric modeling and mapping of a simply supported U-type aqueduct structure based on BIM, characterized by, The method comprises the following steps: S1, determining the size meeting the aqueduct hydraulic conditions according to the engineering requirements, including the longitudinal and transverse sizes of the aqueduct body, and the positions and types of the prestressed steel bars and the steel bars; S2, establishing a local coordinate system in the main coordinate system corresponding to the position where the cross section of the aqueduct body changes, and all the local coordinate systems are consistent with the direction of the main coordinate system; S3, according to the size data of the aqueduct, first drawing a sketch on the cross section perpendicular to the longitudinal direction of the aqueduct body at the position of the local coordinate system, and parameterizing the shape and size parameters on the cross section to obtain the transverse parameters, then obtaining the longitudinal parameters according to the position where the cross section of the aqueduct body changes, and finally establishing a three-dimensional construction model template in the BIM software according to the transverse parameters and the longitudinal parameters; S4, establishing the coordinate points of the starting point and the ending point of the steel bar in the two local coordinate systems of the starting point and the ending point of the steel bar, and connecting them into a straight line to establish a longitudinal prestressed steel bar line, sequentially completing the establishment of the longitudinal prestressed steel bars, forming a longitudinal prestressed steel bar group, and giving the longitudinal prestressed steel bars the number and diameter attributes; offsetting the inner wall water-facing surface to the normal direction of the outer side of the aqueduct body to obtain an offset surface, intersecting a plane perpendicular to the center line of the aqueduct with the offset surface to obtain the shape of the ring-shaped prestressed steel strand, and extending the two ends upward by a distance to generate a ring-shaped prestressed steel bar, moving and copying the ring-shaped prestressed steel bar on the offset surface along the length direction of the aqueduct body to obtain a ring-shaped prestressed steel bar group, and giving the ring-shaped prestressed steel bar the number and diameter attributes; establishing a parameterized prestressed steel bar model template according to the longitudinal and ring-shaped prestressed steel bar groups; S5, selecting a surface or a surface group composed of several surfaces of the three-dimensional construction model template, setting the thickness of the protective layer as c, the diameter of the first layer of steel bars close to the surface as d1, and the diameter of the second layer of steel bars as d2; offsetting the selected surface or surface group inward along the normal direction thereof by c+0.5d1 to obtain a first offset surface, intersecting a plane perpendicular to the first offset surface with the first offset surface to obtain the preliminary shape of the ring-shaped steel bar, extending the two ends upward by a distance and hooking to generate a ring-shaped steel bar, moving and copying the ring-shaped steel bar on the first offset surface to obtain a ring-shaped steel bar group, and giving the ring-shaped steel bar the type and diameter attributes; offsetting the selected surface or surface group inward along the normal direction thereof by c+d1+0.5d2 to obtain a second offset surface, intersecting a horizontal plane with the second offset surface to obtain the preliminary shape of the longitudinal steel bar, moving and copying the longitudinal steel bar on the offset surface along the tangential direction thereof to obtain a longitudinal steel bar group, and giving the longitudinal steel bar the type and diameter attributes; establishing a parameterized steel bar model template according to the longitudinal and ring-shaped steel bar groups; S6, selecting the position where the aqueduct body needs to be cut, and obtaining a parameterized cutting surface by establishing the coordinate points of four points of the cutting surface in the local coordinate system; S7, according to the drawing program of the BIM software, three-dimensional construction model templates, prestressed steel beam model templates and steel bar model templates are sequentially called, and each parameter is input into the corresponding template according to the longitudinal dimension, transverse dimension, position and type of the prestressed steel beam and steel bar of the trough body determined in S1, so as to generate a three-dimensional construction drawing of the aqueduct, and then a sectioning program of the software is called, and sectioning surface parameters are input, so as to generate a trough body layout drawing, a prestressed steel beam layout drawing and a steel bar layout drawing.

2. The BIM-based parametric modeling and mapping method of simply supported U-type aqueduct structure according to claim 1, wherein, The transverse parameters include: an inner side gangar width B1, a standard section wall thickness B2, a standard section outer side gangar width B3, a standard section outer side straight wall section height H1, an inner wall straight wall section height H2 of a water-facing surface, a gangar height H3, a pull rod height H4, a water-facing surface circular arc radius R0, a trough body outer wall circular arc radius R1, a standard section bottom thickening zone height H0, a standard section bottom surface length L1, an end rib bottom thickening zone height H5, an end rib outer side straight wall section height H6, an end rib bottom length L2 and a water stop trough width B4.

3. The BIM-based parametric modeling and drafting method of simply supported U-type aqueduct structure according to claim 2, wherein, The longitudinal parameters include: a trough body total length W1, a gradual change section length W2, an end rib length W3, a post-cast strip length W4, a water stop trough length W5, a pull rod width W6, a pull rod spacing W7 and whether a pull rod is arranged at a mid-span position.

4. The BIM-based parametric modeling and drafting method of simply supported U-type aqueduct structure according to claim 3, wherein, In S3, when the three-dimensional model template is constructed by the BIM software, the following steps are included: S31, by a plane generation instruction, a trough starting plane, a water stop trough ending plane, a post-cast strip division plane, a gradual change section starting plane, a gradual change section ending plane and a mid-span plane are established according to the longitudinal parameters; S32, by a sketch instruction, a trough end rib sketch and a trough end rib water stop trough sketch are drawn on the trough starting plane, a gradual change section sketch is drawn on the gradual change section starting plane, and a standard section sketch is drawn on the gradual change section ending plane; S33, by a stretching command, an end rib model and a standard section model are generated by stretching the end rib sketch and the standard section sketch, the end rib model is stretched to the gradual change section starting plane, the standard section model is stretched to the mid-span plane, a gradual change section model is generated by connecting the gradual change section sketch and the standard section sketch through a multi-section envelope body command; S34, by a sketch command, a pull rod section sketch is drawn on the mid-span plane, a central position pull rod model is generated by a stretching command, and in the formula setting, when the parameter of "whether a pull rod is arranged at a mid-span position" is 1, the pull rod is located at the mid-span, and when the parameter is 0, the pull rod center is at a distance of W7 / 2 from the mid-span plane, the trough body total length W1 is applied in the formula setting, and by an array command, the pull rod model is arrayed according to the pull rod spacing parameter, so as to obtain a central pull rod and an end pull rod; S35, by an adding command, the end rib model, the gradual change section model, the standard section model, the central pull rod and the end pull rod are combined into a whole half-span model; S36, first, by a stretching command, a water stop trough sketch is stretched to establish a water stop trough model, and then by a subtracting command, the water stop trough model is subtracted from the whole half-span model. S37, draw the end ring two-stage anchor concrete sketch at the aqueduct starting point plane, draw the middle ring two-stage anchor concrete sketch at the cross section, stretch the end ring two-stage anchor concrete sketch and the middle ring two-stage anchor concrete sketch by the stretching command, establish the end ring two-stage anchor concrete model and the half-span middle ring two-stage anchor concrete model, subtract the end ring two-stage anchor concrete model and the half-span middle ring two-stage anchor concrete model from the whole half-span model by the subtracting command to obtain the concrete half-span model, and then split the concrete half-span model into the post-cast strip model and the first-stage concrete half-span model by the splitting command; S38, mirror the post-cast strip model, the first-stage concrete half-span model and the ring two-stage anchor concrete model through the cross section mirror command, combine the two half-span models into the concrete model by the adding command, and combine the two half-span middle ring two-stage anchor concrete models into the middle ring two-stage anchor concrete model, thereby completing the construction model template establishment.

5. The BIM-based parametric modeling and drafting method of simply supported U-type aqueduct structure as claimed in claim 1, wherein, In S4, the prestressed steel bar model template is established by the BIM software, including the following steps: establishing the steel bar model by RebarSmart, selecting the steel bar plane, then selecting the steel bar guide line, and finally setting the interval first segment distance, interval end distance, steel bar spacing, steel bar extension, steel bar type and steel bar diameter to generate the steel bar.

6. The BIM-based parametric modeling and drafting method of simply supported U-type aqueduct structure as claimed in claim 1, wherein, In S5, the steel bar model template is established by RebarSmart, the steel bar plane is selected, then the steel bar guide line is selected, and finally the interval first segment distance, interval end distance, steel bar extension and hook, steel bar type and steel bar diameter are set to generate the steel bar.

7. The BIM-based parametric modeling and drafting method of simply supported U-type aqueduct structure as claimed in claim 1, wherein, In S4 and S5, the prestressed steel bar and the steel bar are extended and bent, and the point positions of each segment are calculated according to the following principle: S51. Initial straight segment AB, starting coordinate , ending coordinate , obtaining a direction vector of AB wherein ; S52. Extend BC for the first time by length L1 to get endpoint ; S53. The hook needs to be generated in a plane perpendicular to the straight line, the normal direction vector of the hook plane is selected ; S54. Calculate the center of the hook, ; S55. A hook is generated, and the hook parameter equation is: , hook end point , and are two unit vectors normal to each other lying in the hook plane; Wherein, the center is O, the radius is R, the initial angle is 0°, the terminal angle is α, and β represents the rotation angle of the point on the circular arc relative to the initial edge; S56. Direction vector after secondary extension of the hook , extension distance L2, extension end point .

8. The BIM-based parametric modeling and drafting method of simply supported U-type aqueduct structure of claim 1, wherein, In S7, the channel body layout drawing, prestressed steel bar layout drawing and steel bar layout drawing are generated, the drawing layout of the aqueduct is in the order of channel body construction drawing, prestressed steel bar layout drawing and steel bar layout drawing, the three types of drawings are arranged in the order of elevation layout and cross section layout, then the viewport layout is arranged according to the required drawing size, each viewport layout is customized, the model is orthographic projection and perspective projection, or the model is cut to obtain the cut construction, finally the projection is dimensioned, the channel body quantity, prestressed steel bar quantity and steel bar quantity are counted by the engineering quantity table, then the printing parameters can be designed to generate the drawings.

Images