Irregular arc-shaped concrete wall formwork construction method based on BIM technology

Abstract

The invention discloses an irregular arc-shaped concrete wall template construction method based on a BIM (Building Information Modeling) technology, which comprises the following steps of: 1, importing a wall model and a structure chart into Revit software, and carrying out structural modeling on beams and plates based on the wall model to form a structural Revit model; 2, importing the architectural drawing into a structure Revit model, carrying out architectural modeling to obtain a Revit model, and checking whether data provided by the architectural drawing and the structure drawing conflict or not in the Revit model; 3, if the data provided by the architectural drawing and the structural drawing do not conflict, creating a vertical profile map based on a Revit model; if the data conflicts, after negotiating with a design unit, creating a vertical profile map based on a Revit model determined after negotiation; 4, creating a transverse profile map based on the wall elevation; and 5, importing a CAD drawing based on the vertical profile map and the transverse profile map in the Revit model, and guiding the construction of the wall body and the template. The method is suitable for irregular arc-shaped concrete structures which are incomplete in drawing data and cannot be guided to be constructed purely by drawings.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and particularly to a construction method for formwork of an irregular curved concrete wall based on BIM technology. Background Art

[0002] With the development of the times, building construction technology has been continuously progressing, and more and more special-shaped structures and special processes have emerged in the building field.

[0003] In a certain project, the art building has a unique shape, which is a double-curved special-shaped concrete arc wall, resembling a flower bud, with a building area of 1292 ㎡. Its vertical structures such as walls and columns have certain arcs, inclinations and angles in space, and the angles will change with the position of the length or height of the wall columns. However, the structure drawings and architectural drawings provided by the design unit can only provide the general positions and the corresponding reinforcement or functional markings of the rooms, and the data is incomplete, making it difficult to guide the on-site construction. Summary of the Invention

[0004] The present invention provides a construction method for formwork of an irregular curved concrete wall based on BIM technology. This process gives full play to the visualization characteristics of BIM technology and can present the original abstract architectural design in an intuitive three-dimensional model. Construction workers can clearly see the shapes, positional relationships in space and details of structures such as walls and columns, greatly improving the understanding of the design intent and reducing misunderstandings and errors during the construction process.

[0005] The technical problem to be solved is: the construction difficulties brought by complex building shapes.

[0006] To solve the above technical problem, the present invention adopts the following technical solutions: The construction method for formwork of an irregular curved concrete wall based on BIM technology of the present invention includes the following steps: Step 1: Import the wall model and structure drawings into the Revit software, and perform structural modeling of beams and slabs based on the wall model to form a structural Revit model; Step 2: Import the architectural drawings into the structural Revit model, perform architectural modeling to obtain a Revit model, and check whether the data provided by the architectural drawings and the structure drawings conflict in the Revit model; Step 3: If the data provided by the architectural drawings and the structure drawings do not conflict, create a vertical sectional view based on the Revit model; if the data conflicts, after consulting with the design unit, create a vertical sectional view based on the determined Revit model after consultation; Step 4: Create a horizontal sectional view based on the wall elevation; Step 5: Import CAD drawings based on the vertical and horizontal sections in the Revit model to guide the construction of walls and formwork.

[0007] The irregular curved concrete wall formwork construction method of the present invention is based on BIM technology. Further, in step one, the wall model is imported into Revit software, and each wall is analyzed to obtain the curvature, inclination and inclination angle data of each wall and the inclination and inclination angle change nodes, determine the wall model that needs to be further designed, and create a vertical section view and a horizontal section view based on the wall model that needs to be further designed.

[0008] The irregular arc concrete wall formwork construction method of the present invention is based on BIM technology. Further, in step 2, it is checked whether there is a conflict between the architectural drawings and the Revit model in terms of spatial expression; whether the opening positions are consistent; and whether the height of the beam and slab components affects the usability of the building.

[0009] The irregular arc concrete wall formwork construction method of the present invention is based on BIM technology. Further, in step three, a vertical section view is created in Revit software for the wall curvature change point and the intersection with the axis.

[0010] The irregular arc concrete wall formwork construction method of the present invention is based on BIM technology. Further, based on the vertical section diagram, the degree of change of the wall in the horizontal and vertical directions with the length and height is obtained; the radius value of the specific bending arc of the wall is accurately calculated; and the distance of the wall from the axis and the change position are clearly defined.

[0011] The irregular arc concrete wall formwork construction method of the present invention is based on BIM technology. Further, in step 5, the transverse section view is imported into the CAD drawing, and the coordinates are set at the transverse section position of the wall in combination with the axis distribution diagram.

[0012] The irregular arc concrete wall formwork construction method based on BIM technology of the present invention further includes step six, changing the wall in the Revit model into a curtain wall system, and determining the size and position of the formwork by utilizing the characteristic that the curtain wall can change its size.

[0013] The present invention discloses an irregular arc concrete wall formwork construction method based on BIM technology, and further utilizes a vertical section view to determine a support scheme and a construction sequence of the formwork.

[0014] The present invention is based on the irregular arc concrete wall formwork construction method of BIM technology. Furthermore, the formwork construction sequence is as follows: first construct the top plate formwork and the support system to determine the upper position of each wall layer, then construct the inner wall formwork to adjust the curvature, fix it to the support frame with through-wall screws, then tie the wall column steel bars, then construct the outer wall formwork and reinforce it, and finally carry out concrete pouring and formwork removal.

[0015] The construction method of the formwork for irregular arc-shaped concrete walls based on BIM technology. Further, the support scheme is specifically as follows: wooden formwork is used as the wall formwork, with vertical wooden keels arranged outside, steel bars are used as the horizontal main keels and are arranged outside the vertical wooden keels, and finally the wall formwork is fixed using through-wall screw rods.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This process gives full play to the visualization characteristics of BIM technology, and can present the originally abstract architectural design in the form of an intuitive three-dimensional model. Construction workers can clearly see the forms, positional relationships in space and details of various parts such as walls and columns, greatly improving the understanding of the design intent and reducing misunderstandings and errors during the construction process; 2. Optimize the requirements for the arc of the wall formwork through BIM technology, deeply study the characteristics of the wall structure, and accurately design the splicing method and support system of the formwork according to the arc requirements of different parts; for complex curved walls, use BIM technology to simulate the stress conditions and construction feasibility under different formwork combination schemes, so as to determine the optimal formwork layout; at the same time, deepen the wall formwork support system to ensure that, on the premise of meeting the requirements of construction safety and quality, the waste of materials and construction difficulty are reduced as much as possible; 3. This application is applicable to irregular arc-shaped concrete structure projects with incomplete drawing data and unable to solely rely on drawings to guide construction. It specifically covers the formwork detailed design, formwork reinforcement and actual construction process; 4. In this application, the Rhino software model is imported into the Revit software. Use the Revit software to make a section in the arc-shaped wall to analyze the arc shapes of the arc-shaped walls at different elevations. Through this operation, the specific forms of the arc-shaped walls at different heights can be clearly presented, providing key data support for subsequent construction; 5. Use the results of the CAD horizontal section and vertical section exported from Revit to deepen and analyze the formwork support system. Based on the analysis results, plan the construction sequence, which is basically to first construct the inner formwork, shape the curved shape, then carry out the wall steel bar binding, and finally close the outer wall formwork. In the construction of the formwork support system, square timbers are used as the vertical formwork keels and steel bars are used as the horizontal formwork keels to ensure the forming quality of the wall concrete and meet the design shape requirements.

[0017] The following further illustrates the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the Revit model diagram of the building of the present invention; Figure 2This is the wall decomposition diagram of the present invention; Figure 3 This is the schematic diagram of the wall of the present invention being converted into a curtain wall system in the Revit model; Figure 4 This is the structural diagram of the present invention; Figure 5 This is the architectural drawing of the present invention; Figure 6 This is the intersecting diagram of the horizontal cross-section of the wall of the present invention and the axis; Figure 7 This is the vertical sectional view of the wall of the present invention; Figure 8 This is the schematic diagram of the formwork support structure of the present invention.

[0019] Reference numerals: 1, wall; 2, axis; 3, support system; 4, inner formwork; 5, through-wall screw rod; 6, horizontal main keel; 7, vertical keel; 8, outer formwork. Detailed implementation manners

[0020] As Figures 1-8 shown, the present invention relates to a construction method for the formwork of an irregular arc-shaped concrete wall based on BIM technology, including the following steps: Step 1: Model import and analysis The model initially used in the project is the Rhino model provided by the design unit. This model has no specific data and cannot guide the specific construction.

[0021] Based on the Rhino model provided by the design unit, it is imported into the Revit software, the model is decomposed, and each wall is analyzed to obtain the radian, inclination, and dip angle data of each wall, as well as the nodes of inclination and dip angle changes, and determine the wall models that need to be deeply designed. The following takes the example of this project for illustration: The decomposed walls are numbered, and the walls are divided into four types: walls A, B, C, and D. Each wall is analyzed. After analysis, it is determined that wall A is the longest and most complex curved wall. Its vertical curvature changes with the length. Vertically, the starting stage of wall A is divided into two parts: from the first floor to the second floor and from the second floor to the roof parapet. The bending angles and curvatures of the walls in these two stages are different. The inclination angle of the wall from the first floor to the second floor is 82°, and the inclination angle from the second floor to the parapet is 77°. And a large part from the second floor to the top of the parapet is an arc wall with a radius of 4683 mm. As the length of wall A extends, its inclination angle and curvature gradually decrease, and it changes into a right-angle wall of 90° in the middle stage and then changes into a wall with a maximum outer inclination angle of 93° in the later stage. Through the above analysis, wall A has a complex curved surface change and a long wall length, which is the key point for in-depth design.

[0022] Wall B has a certain inclination angle. The inclination angle from the first floor to the second floor is 85°, and the inclination angle from the second floor to the parapet wall on the roof is 80°. There is also an arc wall with an upper radius of 981 mm, and the wall length is relatively short.

[0023] Wall C has the most complex vertical shape. From the first floor to the second floor, it is an inclined wall with an inclination angle of 86°. From the second floor to the parapet wall, it is an arc wall with a diameter of 18138 mm. Above the parapet wall, the shaped wall is an arc wall with a diameter of 3777 mm. Although the structural shape of Wall C is complex, its length is the shortest.

[0024] Wall D is just an arc wall with an overall inclination angle of 93°. There is not much difficulty in the construction process, but attention should be paid to the arc angle shape at the top during the detailed construction process.

[0025] Step 2: Secondary modeling: Based on the wall model and structure diagram in Rhinoceros software, perform the structural modeling of beams and slabs in Revit software to form a structural Revit model. After the modeling is completed, import the architectural drawing into the structural Revit model to perform architectural modeling to obtain the Revit model. Conduct a checking work in the Revit model to check whether the data provided by the architectural drawing and the structure diagram conflict. If the data provided by the architectural drawing and the structure diagram do not conflict, create a vertical sectional view based on the Revit model; if the data is inconsistent, after consulting with the design unit, create a vertical sectional view based on the Revit model determined after the consultation.

[0026] The above-mentioned checking work focuses on checking whether there are conflicts in the spatial representation between the architectural drawing and the structure diagram, whether the opening positions of the openings are consistent, and whether the heights of components such as beams and slabs affect the building's functional use.

[0027] The following is illustrated with an example of this project. After checking, it is found that there are significant differences in the wall curvature and the positions of door and window openings between the architectural Figure 2 floor and the structural Figure 2 floor. Through comparative analysis in the Revit model, it is known that both the architectural and structural drawings are extracted and detailed from the Revit model. During the extraction process, there are elevation errors, resulting in this error. Subsequently, after consulting with the design unit, it is decided to use the architectural drawing for the construction of the building.

[0028] Step 3: Scheme design and detailing: Create vertical sectional views of the wall at the locations where the wall curvature changes and at the intersections with the axis in Revit software. Through the vertical sectional views, analyze in detail the degree of change of the wall in the horizontal and vertical directions with the change of length and height; accurately calculate the radius value of the specific bending curvature, clarify the distance between the wall and the axis and the position where the distance changes. Through these operations, specific numerical information about the wall is obtained in the Revit model.

[0029] Importing the vertical section drawing and the numerical information of the wall into the CAD software facilitates the construction guidance and the subsequent use of the vertical section drawing for further analysis and design work.

[0030] In order to facilitate the guidance of construction, the vertical section drawing is imported into the CAD software, and the intersection of the axes is used as the node. Each wall is numbered, and the intersection of the axes and the locations where the curvature, inclination and inclination of the wall body change significantly are numbered to analyze the changes in the shape of wall columns to facilitate the guidance of construction.

[0031] Taking Wall No. 5 of this project as an example, it includes nodes numbered as Node 5, Node 6, and Node 7. As the length of the wall changes, the curvature of its height also changes. In Node 5, the angles are 86°, 83°, and 83° from bottom to top; in Node 6, the angles are 89° from bottom to top; and in Node 7, the angles are 90°, 91°, and 92° from bottom to top.

[0032] Although the vertical section view can show the angle details of each wall in detail, this deepening method cannot fully meet the needs of on-site construction. On the one hand, it cannot clearly present the relationship between the wall and the axis. In on-site construction, although the wall varies, the axis is fixed, and it is necessary to rely on the relationship between the two to position the steel bars and the formwork. On the other hand, the curvature of the wall varies greatly, and it is difficult to fully and detailedly display the relevant data only by the vertical section view.

[0033] Therefore, a transverse section view is created based on the wall elevation in the Revit model, and the transverse section view is imported into the CAD software. Combined with the axis distribution diagram, coordinates are set at the transverse section position of the wall for some node positions such as the place where the wall curvature changes and the intersection with the axis, which is convenient for RTK use. The biggest advantage of the newly added transverse section view is that it can be imported into RTK handheld devices for locating the steel bar position and the template position, thereby achieving accurate wall layout.

[0034] In the present application example, after multiple transverse analyses, the optimal elevations of the transverse section are determined to be 915mm, 450mm and 100mm, and the width is set to 1830mm. This is because 915mm×1830mm is exactly the size of the glued wood formwork, and the section with a height of 450mm can meet the bending angles of most wall formworks. For cases where individual angles are too large, smaller formwork pieces are used.

[0035] Step 4: Deepen the template plan: Change the walls in the Revit model into a curtain wall system, use the characteristic of the curtain wall that can change size to determine the size and position of the formwork, and use the vertical section view to determine the support plan and construction sequence of the formwork.

[0036] The construction sequence is as follows: First, construct the roof formwork and support system to determine the position of the upper mouth of each layer of wall. Then, construct the inner side formwork of the wall and make fine adjustments to the arc. Fix it on the support system with through-wall screw rods. Next, bind the wall column steel bars. At this time, the wall column steel bars can be bent along with the arc of the determined inner side wall formwork. Subsequently, construct the outer side formwork of the wall and reinforce it.

[0037] At the same time, the wall reinforcement system was analyzed. The traditional wooden keel cannot meet the construction of the arc-shaped wall in the horizontal direction. Therefore, steel bars with a diameter of 14 mm are used as the horizontal main keel, and the vertical keel uses a 40 mm X 70 mm wooden keel. The vertical wooden keel not only has to play a fixing role, but also has to bear the extrusion force of the horizontal steel bar keel and ensure the smooth transition of the upper and lower arcs. Therefore, the spacing is relatively dense, ranging from 100 mm to 150 mm.

[0038] Specifically: 1) Measurement and setting out: Carry out measurement work by combining a total station and an RTK device. The total station has high surveying and mapping accuracy, but the operation process is relatively complex. The total station is only used for the coordinate surveying and mapping of important control points, such as the intersection of axes, frame columns, wall ends and other parts. Accurately survey and map on the entity according to the drawing coordinates to serve as the main control points.

[0039] After determining the main control points with the total station, use a handheld RTK device to survey and map the detailed arc-shaped axis. The handheld RTK has the advantages of being portable, easy to operate and having relatively high surveying and mapping accuracy. Although its accuracy is slightly inferior to that of the total station, it meets the allowable surveying and mapping error range of the main structure, and the accuracy meets the requirements.

[0040] The wall control line is derived from the axis. At the construction site, survey and map the wall body control line 500 mm away from the wall edge. This control line is mainly used to control the position of the wall formwork. Since the wall control line is also arc-shaped, it is necessary to rely on the axis measurement results and lead it to the corresponding position for setting out.

[0041] For the vertical wall bending arc control line, measure and set out the projection line on the foundation plane along the distance of 915 mm in height according to the transverse sectional view of the relationship between the wall at different elevations and the axis position. During the on-site inspection process, a plumb bob tool can be used as an auxiliary to check and correct the wall arc.

[0042] 2) Construction of the top plate formwork: Select scaffolding materials with reliable quality and load-bearing capacity meeting the design requirements, such as steel pipes conforming to national standards. The spacing of the vertical poles should be strictly arranged according to the design plan, generally not exceeding 1.2 m, and the step distance of the horizontal bars should be controlled at about 1.5 m to ensure that the support system has sufficient stability to bear the load of the top plate formwork and subsequent construction. Place a base plate at the bottom of the vertical poles to increase the bearing area and prevent the vertical poles from sinking. At the same time, set diagonal braces at certain intervals around and inside the support system to enhance the overall anti-overturning ability.

[0043] Use qualified plywood formwork. Quality inspection should be carried out when the formwork enters the site to ensure that its thickness is uniform, the surface is flat, and there are no damages. When laying the formwork, ensure that the formwork joints are tight, and the gap between adjacent formworks should not exceed 2 mm. For parts with larger gaps, sealant or tape should be used for sealing to prevent leakage of concrete during pouring. Precise measurement and positioning should be carried out using surveying instruments such as total stations to ensure that the position deviation of the upper opening of the circular arc wall is controlled within the allowable range, providing an accurate benchmark for subsequent construction.

[0044] 3) Construction of the inner formwork: According to the previously determined wall curvature and bending angle, use professional formwork cutting tools, such as saws, to accurately cut the plywood formwork. During the splicing process, ensure that the formwork joints are tight, and use tongue-and-groove splicing or add sealing strips to prevent leakage of slurry. For the formwork of the arc part, use the method of splicing multiple small plates, and adjust the angles and positions of the small plates to make them conform to the designed curvature.

[0045] During the construction process, use the bending projection line for auxiliary measurement, and use surveying instruments such as total stations to monitor the installation angle and position deviation of the formwork in real time.

[0046] 4) Steel bar binding: Double-layer and double-way steel bars with a diameter of 12 mm are used at the position of the circular arc wall. The bending of the arc is not very difficult. Use the bending angle of the inner formwork to bend the steel bars, and fix the bent steel bars on the inner formwork that has been bent using high-strength cushion blocks and iron wires. Bind the steel bars according to the designed spacing. First, bind the vertical steel bars, and then bind the horizontal steel bars. The intersection points are firmly bound with iron wires and arranged in a figure-eight shape to prevent the steel bars from sliding. Use customized top formwork rods and ladder-shaped steel bars to strictly control the wall thickness. The length of the top formwork rods should be accurately processed according to the designed wall thickness. The spacing of the ladder-shaped steel bars is generally about 1 m, and the diameter is the same as or slightly larger than the load-bearing steel bars of the wall to ensure that the wall thickness remains accurate during the construction process.

[0047] 5) Construction of the outer formwork: Install the outer formwork according to the arc shape of the inner formwork to ensure tight splicing and consistent arc between the formworks. At the splicing joints, use sealant or tape for sealing to prevent slurry leakage. During the installation process, check the arc of the formwork with measuring instruments to ensure that the deviation from the arc of the inner formwork is within the allowable range. Fix the strips at the vertical formwork joints to ensure smooth transition of the bending of the arc formwork.

[0048] 6) Concrete pouring and formwork removal: When the concrete strength of the wall reaches the specified proportion of the design strength and meets the formwork removal conditions, the formwork removal work can be carried out. The removal sequence is to remove the outer wall formwork first and then the inner formwork.

[0049] The embodiments described above are only descriptions of the preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. The irregular arc concrete wall formwork construction method based on BIM technology is characterized by: The following steps are involved: Step 1: Import the wall model and structural drawing into Revit software, and perform structural modeling of beams and slabs based on the wall model to form a structural Revit model; Step 2: Import the architectural drawings into the structural Revit model, perform architectural modeling to obtain the Revit model, and check in the Revit model whether the data provided by the architectural drawings and the structural drawings conflict; Step 3: If the data provided by the architectural drawing and the structural drawing do not conflict, create a vertical section drawing based on the Revit model; if the data conflict, after consultation with the design unit, create a vertical section drawing based on the Revit model determined after consultation; Step 4: Create a horizontal section view based on the wall elevation; Step 5: Import CAD drawings based on the vertical and horizontal sections in the Revit model to guide the construction of walls and formwork.

2. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 1 is characterized in that: In step one, the wall model is imported into the Revit software, and each wall is analyzed to obtain the curvature, inclination and dip angle data of each wall as well as the dip and dip angle change nodes, determine the wall model that needs to be further designed, and create vertical and horizontal section drawings based on the wall model that needs to be further designed.

3. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 1 is characterized in that: In step 2, check whether there is any conflict in the spatial expression between the architectural drawings and the Revit model; whether the opening positions are consistent; and whether the height of the beam and slab components affects the usability of the building.

4. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 2 is characterized in that: In step three, create vertical sections in Revit software for where the curvature of the wall changes and where it intersects with the axis.

5. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 4 is characterized in that: Based on the vertical section diagram, obtain the degree of change of the wall in the horizontal and vertical directions along the length and height; accurately calculate the radius value of the specific bending arc of the wall; clarify the distance of the wall from the axis and the change position.

6. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 1 is characterized in that: In step 5, the transverse section view is imported into the CAD drawing, and combined with the axis distribution diagram, the coordinates are set at the transverse section position of the wall.

7. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 1 is characterized in that: It also includes step six, which is to change the walls in the Revit model into a curtain wall system, and use the characteristic of the curtain wall that can change size to determine the size and position of the template.

8. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 7 is characterized in that: Use the vertical section drawing to determine the support scheme and construction sequence of the formwork.

9. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 8 is characterized in that: The specific sequence of formwork construction is as follows: first construct the top plate formwork and support system to determine the upper position of each wall layer, then construct the inner wall formwork to adjust the curvature, fix it to the support frame with through-wall screws, then tie the wall column steel bars, then construct the outer wall formwork and reinforce it, and finally carry out concrete pouring and formwork removal.

10. The irregular arc concrete wall formwork construction method based on BIM technology according to claim 9 is characterized in that: The specific support plan is as follows: wooden formwork is used as the wall formwork, external vertical wooden keels are installed, steel bars are used as the transverse main keels and are installed on the outside of the vertical wooden keels, and finally the wall formwork is fixed with through-wall screws.

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