Vertical rotation lifting construction method for large-span space structure

Abstract

The invention discloses a construction method for vertically rotating and lifting a large-span space structure. The construction method is specially used for determining a rotating shaft and vertically rotating according to a preset track in the vertical rotating and lifting process of the large-span space structure. Efficient and safe vertical rotating and lifting of a complex space structure are achieved through the steps of preferably selecting a lifting point, determining the direction and angle of a rotating shaft, leveling the ground posture, selecting the splicing position, accurately controlling different-speed vertical rotating and lifting, lifting the structure in place, finally unloading and dismantling and the like. The method has the advantages that splicing measures and high-altitude operation are reduced through the vertical rotation lifting technology, the ground posture splicing position is optimized, it is ensured that horizontal displacement of the space structure is evenly distributed in the vertical rotation process, and the problems that due to the fact that horizontal displacement is too large, the structure collides with the lifting frame, and the horizontal component force of the lifting frame is too large are solved.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and more specifically to a vertical rotation and lifting construction method for a large-span space structure. Background Art

[0002] In the field of construction, large-span spatial structures are widely used in large public buildings such as gymnasiums and exhibition halls because of their large spatial span and good structural stability. However, during the construction of such structures, especially in confined or space-constrained areas, traditional installation technologies such as block lifting and high-altitude in-situ bulk installation face a series of technical challenges, such as restrictions on the operation of lifting machinery, high safety risks in high-altitude construction, difficulty in controlling the accuracy of high-altitude installation, low efficiency of high-altitude installation construction, and large amounts of assembly or temporary support measures. In order to overcome these problems, researchers and engineers proposed the use of ground assembly + lifting construction methods. However, the existing lifting methods still have limitations, especially when the large-span spatial structure presents a large slope. If the in-situ ground assembly method is adopted, the spatial structure with a large height difference has problems such as a large amount of assembly measures such as the tire frame and low efficiency of high-altitude assembly construction. In the face of these problems, the patent "Irregular Free-Form Steel Grid Rotation Lifting Installation Measurement Method and Device" proposes a rotating lifting method. Although it solves the problem of large amount of assembly measures, the patent does not consider the impact of horizontal displacement caused by changes in the ground assembly posture position. When the slope of the spatial structure is large, rotating and lifting only with the lifting point with the lowest vertical coordinate as the rotation axis will cause the structure to have too large a horizontal displacement far from the rotation axis. On the one hand, excessive horizontal displacement will lead to insufficient rotation space for the structure in a narrow assembly yard, and interference with the lifting frame during the rotation of the structure; on the other hand, excessive horizontal displacement will cause the structure to generate a large horizontal component force at the moment of being ejected, which is not conducive to the design of the lifting tooling and displacement control. In addition, how to adopt a specific asynchronous lifting control method to ensure that the structure can rotate according to the specified rotation trajectory is also a major difficulty in rotary lifting. Summary of the invention

[0003] The present invention provides a large-span space structure vertical rotation and lifting construction method, which aims to solve the technical problems in the existing large-span space structure construction. The different-speed vertical rotation and lifting construction method is adopted to avoid excessive horizontal displacement in the rotation process, solve the problem of different-speed lifting control of each hanging point, and significantly improve the safety and economy of vertical rotation and lifting construction.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] (1) Selection of lifting points: According to the structural characteristics and stress conditions of the spatial structure, the lifting points are generally set at the support nodes at both ends of the vertical rotation axis or their associated nodes.

[0006] (2) Determination of the rotation axis direction and rotation angle: By introducing the fitting plane and the assembly plane, the fitting plane is determined based on the principle of minimizing the sum of the distances from the lower chord node to the fitting plane. The intersection of the fitting plane and the assembly plane is determined as the rotation axis direction, and the included angle is determined as the rotation angle.

[0007] (3) Finding the ground posture and determining the assembly position: The ground posture and position of the structure are determined based on the mapping function between the structural spatial posture and the ground assembly posture, and the assembly frame layout is determined accordingly.

[0008] (4) Different-speed vertical lifting: After the structure is lifted synchronously off the frame by lifting equipment and reaches a certain height, the lifting rates of each lifting point are controlled according to the different distances from each lifting point to the horizontal plane where the rotation axis is located, so as to realize the vertical lifting of the structure from the horizontal assembly posture until it reaches the designed posture, ensuring that all parts of the structure are lifted in a coordinated manner to avoid deformation or damage of the structure.

[0009] (5) Lifting into place: After the structure is lifted vertically to the designed posture, each lifting point is controlled to lift synchronously at the same speed to maintain the designed posture until the spatial structure is lifted into place and installed;

[0010] (6) Unloading and dismantling: The spatial structure is supplemented with rods installed, the spatial structure is unloaded, the lifting frame is dismantled, and the structural installation is completed.

[0011] Furthermore, the selection of lifting points strictly follows the principle of force consistency between the design and the lifting state, and strives to minimize the number of lifters to simplify the construction process and reduce costs.

[0012] Furthermore, the direction of the rotation axis is determined by first defining a fitting plane E, establishing a functional relationship between the sum of the design coordinates of the lower chord nodes of all spatial structures and the vertical distances of the fitting plane E, and using the principle of minimizing the sum of the distances of the lower chord nodes of all spatial structures to plane E. The least squares method is used to solve the equation to obtain the expression of plane E. The direction of the rotation axis is the direction of the intersection of plane E and the horizontal plane.

[0013] Furthermore, the ground assembly posture is shaped by the rotation axis and the rotation angle, and the total amount of the assembly frame measures of the assembly posture after the shape finding is minimized.

[0014] Furthermore, the assembly position of the ground posture is determined based on the principle that the horizontal displacement of the rotated assembly posture relative to the design posture is evenly distributed. The spatial structure is formed at this assembly position, and the horizontal displacement of each lifting point from the lifting point is evenly distributed.

[0015] Furthermore, the lifting rate of each lifting point is calculated by the variation of the lifting rope of each lifting point, and the variation of the lifting rope is obtained as a function of the vertical projection distance from the lifting point to the rotation axis.

[0016] Furthermore, in order to prevent the spatial structure from shifting during the lifting process, limiting measures are taken to ensure that the spatial structure moves according to the predetermined trajectory.

[0017] Furthermore, the limiting measures are as follows: a chain hoist is installed at the corner of the lifting space structure and the steel column. The chain hoist is in a relatively loose state before it leaves the frame, and is in a slightly tight state after lifting a certain stroke. The chain hand hoist is used to slowly release the horizontal displacement of the space structure to a static free state. The space structure is synchronously lifted to a height greater than the height difference of the grid, and then switched to an asynchronous lifting mode. The hand hoist assists the space structure in completing the posture rotation by releasing the horizontal displacement in steps, and then the hoist is removed.

[0018] In summary, the present invention achieves efficient and safe vertical lifting of complex spatial structures by carefully selecting lifting points, determining the direction and angle of the rotation axis, accurately determining the ground leveling and assembly position, accurately controlling the vertical lifting at different speeds, lifting the structure into place, and finally unloading and dismantling. Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The different-speed vertical lifting technology reduces assembly measures and high-altitude operations, reduces the risk of high-altitude construction, improves construction efficiency, and shortens the installation period;

[0020] (2) By optimizing the assembly position of the ground posture, the horizontal displacement of the spatial structure during the rotation and leveling of the ground assembly posture is evenly distributed, thus avoiding problems such as insufficient assembly space, collision of the vertical rotation of the structure with the lifting frame, and excessive horizontal force of the lifting frame due to excessive horizontal displacement.

[0021] (3) Through theoretical analysis and control strategies, the difficult problem of rotating a spatial structure along a predetermined trajectory around a specified rotation axis was solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A three-dimensional schematic diagram of the spatial structure of an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the arrangement of a lifting frame according to an embodiment of the present invention;

[0024] Figure 3 This is a flow chart of vertically rotating and lifting a facade according to an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of determining the direction of the rotation axis according to an embodiment of the present invention;

[0026] Figure 5 A schematic diagram of determining a rotation angle according to an embodiment of the present invention;

[0027] Figure 6 It is an illustration of the form-finding and horizontal displacement calculation of the spatial structure assembly posture according to the embodiment of the present invention;

[0028] Figure 7 It is an illustration of the optimization of the ground posture assembly position of the space structure according to the embodiment of the present invention;

[0029] Figure 8 This is a diagram showing the calculation principle of the variation of the lifting rope at the lifting point according to an embodiment of the present invention;

[0030] Fig. 9 This is a schematic diagram of the principle of lifting at different speeds at a lifting point according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is combined with Figures 1 to 9 The specific implementation method of the vertical rotation and lifting construction method of a large-span spatial structure of the present invention is further described in detail.

[0032] The present invention takes a spatial structure as an example, which can be any spatial structure such as a grid, a truss, etc. This embodiment is a grid structure. The maximum height difference of the grid is 13.3m, which will lead to a significant increase in the amount of assembly measures and an increase in the risk of high-altitude operations. In order to meet these challenges, an innovative construction strategy was adopted: first, horizontal assembly was carried out on the top plate of the basement, and then the grid was adjusted to the design posture through vertical lifting technology in the low altitude, and finally it was accurately lifted to the predetermined design coordinate position.

[0033] like Figure 1 The figure shows the spatial structure grid according to an embodiment of the present invention.

[0034] like Figure 2 As shown, it is a schematic diagram of the arrangement of lifting points during the lifting construction process according to an embodiment of the present invention.

[0035] A method for vertically rotating and lifting a large-span spatial structure, such as Figure 3 As shown, the following steps are included:

[0036] (1) Selection of lifting points: According to the structural characteristics and stress conditions of the spatial structure, the lifting points are generally set at the support nodes at both ends of the vertical rotation axis or their associated nodes. Figure 2 As shown, in this embodiment, specifically: 8 lifting points are set on the top of the structural column, and the lifting points are set based on the principle of ensuring safe and reasonable force during the structure lifting process and economical and reasonable lifting measures.

[0037] (2) Determination of the rotation axis direction and rotation angle: By introducing the fitting plane and the assembly plane, the fitting plane is determined based on the principle of minimizing the sum of the distances from the lower chord node to the fitting plane. The intersection of the fitting plane and the assembly plane is determined as the rotation axis direction, and the angle is determined as the rotation angle. In this embodiment, the specific method for determining the rotation direction and rotation angle is as follows:

[0038] like Figure 4As shown, in this embodiment, the direction of the rotation axis is determined by first defining a fitting plane E, the expression of the plane E in space is z = Ax + By + C, and the spatial coordinates of the i-th lower chord node of the spatial structure in the design state are defined as (x i ,y i , z i ), then the distance from the lower chord node to plane E is Establish the functional relationship between the design coordinates of all lower chord nodes of the spatial structure and the sum of the vertical distances of plane E Based on the principle that the sum of the distances of all the lower chord nodes of the spatial structure to the plane E is the minimum, find the minimum value of the function S. i is a nonlinear function of A, B, and C. To simplify the calculation, we can approximate the solution by taking the sum of squares, that is, to find the function The minimum value of . Taking the partial derivatives of A, B and C for S' and setting them equal to zero, we can get three partial differential equations: Solving the equations gives the values ​​of A, B, and C, thus determining the expression of plane E. The direction of the rotation axis is the direction of the intersection of plane E and the horizontal plane. The expression of the intersection of plane E and the horizontal plane is:

[0039] like Figure 5 As shown, the side elevation projection of the spatial structure is made in the direction of the rotation axis. The rotation angle is the angle between plane E and the horizontal plane. In this embodiment, the rotation angle is 5°.

[0040] (3) Finding the ground posture and determining the assembly position: Determine the ground posture and position of the structure based on the mapping function between the structure's spatial posture and the ground assembly posture, and determine the assembly frame layout accordingly. Figure 6 As shown, in this embodiment, the ground posture shape-finding method is: take the lowest point lifting point as the rotation point, and draw a straight line with the direction of the rotation axis as the vector, then the distance from the highest point lifting point to the straight line is L, and the spatial structure is rotated 5° around the straight line to obtain the ground assembly posture. At this time, the horizontal displacement D=L-Lcosθ caused by the rotation of the ground assembly posture. It can be seen from the formula that the magnitude of the horizontal displacement is related to the projection distance and rotation angle of the lowest and highest points of the lifting point to the rotation axis. When the distance and rotation angle are too large, the horizontal displacement is too large, which will cause the highest point lifting point to collide with the lifting frame after rotation, and the horizontal component force of the lifting frame is too large. Therefore, the processing of the horizontal displacement is very important. In this embodiment, the projection distance of the highest point to the rotation axis is 105317mm, the rotation angle is 5°, and the horizontal displacement is 400mm. The horizontal displacement of the embodiment is too large, and there is a situation of collision with the lifting frame, and the horizontal displacement needs to be processed.

[0041] like Figure 7As shown, the assembly position of the ground posture is determined based on the principle that the horizontal displacement of the assembly posture after rotation is uniformly distributed relative to the design posture. In this embodiment, the ground assembly posture obtained around the lowest point lifting point as the rotation axis causes the highest point lifting point to have the most unfavorable horizontal displacement of 400mm after rotation. Half of the most unfavorable horizontal displacement, that is, D / 2=200mm, is taken as the correction displacement value of the ground posture assembly position. The ground posture assembly position after correction can make the horizontal displacement of the spatial structure uniformly distributed after rotation. At this time, the lifting rope presents an eight-shaped shape, the lifting rope of the lowest point lifting point is offset to the left by 200mm, the lifting rope of the highest point lifting point is offset to the right by 200mm, and the horizontal displacements of the remaining lifting points are all less than 200mm. The spatial structure of this horizontal displacement value will not collide with the lifting frame during the rotation process.

[0042] (4) Different-speed vertical lifting: After the structure is synchronously lifted off the frame and reaches a certain height using the lifting equipment, the different lifting rates of each lifting point are controlled according to the different distances from each lifting point to the horizontal plane where the rotation axis is located, so as to realize the vertical lifting of the structure from the horizontal assembly posture until it reaches the designed posture, ensuring that all parts of the structure are lifted in a coordinated manner to avoid deformation or damage of the structure. In this embodiment, the specific method of different-speed vertical lifting control is as follows: after the spatial structure is assembled on the ground, it is synchronously lifted to a height greater than the maximum height difference of the grid, and then switched to asynchronous lifting mode. The lifting rate of each lifting point is calculated by the change in the lifting rope of each lifting point, and the change in the lifting rope is obtained by the functional relationship of the vertical projection distance from the lifting point to the rotation axis.

[0043] like Figure 8 As shown, it is assumed that the rotation axis is located at any position between the lowest lifting point and the highest lifting point of the structure. For any low lifting point i, the length of the lifting rope in the assembly posture can be defined as l i , the length of the lifting rope under the design condition is l i ', the vertical distance from the lifting point to the rotation axis is defined as l 0i , and the angle between the design posture and the assembly posture of the lifting rope is α. Therefore, the change of the lifting rope at this lifting point can be expressed as Δl i = l i -l i ', considering that the angle α is usually small, we can approximate Δl i = l 0i ·sinθ; Similarly, for any high lifting point j, we can approximate Δl j = l 0j ·sinθ. Assume that within a specified time t, the lifting rate of the low lifting point i is v i , then in order to satisfy the rotation of the structure from the assembly posture to the design posture, the lifting rate of the high lifting point j should be Among them l ijis the vertical distance between lifting points i and j. From the formula, it can be seen that the lifting rate of high lifting point j has nothing to do with the position of the rotation axis, but is related to the distance from other lifting points and the rotation angle θ. The farther the distance between the two lifting points, the greater the difference in lifting rate. Therefore, in the process of vertical lifting using the different speed control structure, selecting any position as the rotation axis can meet the requirements.

[0044] In actual lifting construction, for lifting points higher than the rotation axis, the lifting rope will be shortened; and for lifting points lower than the rotation axis, the lifting rope needs to be lengthened. Since lengthening the lifting rope is difficult to achieve in actual operation, the rotation axis is positioned at a position where all lifting points are higher than the rotation axis. In order to simplify the positioning of the rotation axis, this embodiment uses the lowest lifting point as the position of the rotation axis. Fig. 9 In order to control the structure to complete the vertical rotation at a low altitude as much as possible, the change of the lifting rope at the lowest point C0 can be preferably controlled to 0. In this way, there is no need to adjust the length of the lifting rope during the vertical rotation and lifting process. It is only necessary to fix the lifting point, which can reduce the distance the structure moves upward during the vertical rotation process. For other high lifting points j, the change of the lifting rope is shortened. Through the formula Δl j = l 0j ·sinθ is calculated, and then the lifting speed at different lifting points is calculated within the specified time t according to the change of the lifting rope to complete the vertical rotation and lifting of the structure from the assembled posture to the designed posture.

[0045] In order to ensure that the lifting point can rotate accurately according to the designed rotation trajectory and prevent the spatial structure from swinging horizontally after being separated from the assembly frame, thereby avoiding collision with the lifting frame and causing safety problems, this embodiment adopts limiting measures to control the change of horizontal displacement. In addition, in order to facilitate the control of vertical rotation and lifting, we divide the lifting rope change amount of all lifting points in the vertical rotation and lifting process and the horizontal displacement limiting measures into 10 stages for gradual adjustment, so that the entire process of slowly lifting the grid from the ground posture to the designed posture can be more accurately controlled. Through the above measures, the stability and safety of the entire lifting process can be ensured, while improving construction efficiency and accuracy.

[0046] (5) Lifting into place: After the structure is lifted vertically to the designed posture, each lifting point is controlled to lift synchronously at the same speed to maintain the designed posture until the spatial structure is lifted into place and installed;

[0047] (6) Unloading and dismantling: The spatial structure is supplemented with rods installed, the spatial structure is unloaded, the lifting frame is dismantled, and the structural installation is completed.

[0048] In particular, in order to prevent the spatial structure from shifting during the lifting process, the limiting measures taken in this embodiment are as follows: a chain hoist is installed at the corner of the lifting spatial structure and the steel column, and the chain hoist is in a relatively loose state before leaving the tire frame, and is in a slightly tight state after lifting 300mm. The chain hand hoist is used to slowly release the horizontal displacement of the spatial structure to a static free state, and the spatial structure is synchronously lifted to a height greater than the height difference of the grid, and then switched to the asynchronous lifting mode. The hand hoist assists the spatial structure in completing the posture rotation by releasing the horizontal displacement in steps, and then the hoist is removed.

[0049] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A method for vertically rotating and lifting a large-span spatial structure, characterized in that: The following steps are involved: (1) Selection of lifting points: According to the structural characteristics and stress conditions of the spatial structure, the lifting points are set at the support nodes or their associated nodes at both ends of the vertical rotation axis; (2) Determination of the rotation axis direction and rotation angle: By introducing the fitting plane and the assembly plane, the fitting plane is determined based on the principle of minimizing the sum of the distances from the lower chord node to the fitting plane. The intersection of the fitting plane and the assembly plane is determined as the rotation axis direction, and the included angle is determined as the rotation angle. (3) Finding the ground posture and determining the assembly position: Determine the ground posture and position of the structure based on the mapping function between the structure's spatial posture and the ground assembly posture, and determine the assembly frame layout accordingly; (4) Different-speed vertical lifting: After the structure is lifted synchronously off the frame by lifting equipment and reaches a certain height, the lifting rates of each lifting point are controlled according to the different distances from each lifting point to the horizontal plane where the rotation axis is located, so as to realize the vertical lifting of the structure from the horizontal assembly posture until it reaches the designed posture, ensuring that all parts of the structure are lifted in a coordinated manner to avoid deformation or damage of the structure; (5) Lifting into place: After the structure is lifted vertically to the designed posture, each lifting point is controlled to lift synchronously at the same speed to maintain the designed posture until the spatial structure is lifted into place and installed; (6) Unloading and dismantling: The spatial structure is supplemented with rods installed, the spatial structure is unloaded, the lifting frame is dismantled, and the structural installation is completed.

2. The method for vertically rotating and lifting a large-span space structure according to claim 1 is characterized in that: The direction of the rotation axis is determined by first defining a fitting plane E, establishing a functional relationship between the sum of the vertical distances between the design coordinates of all the lower chord nodes of the spatial structure and plane E, and using the principle of minimizing the sum of the distances of all the lower chord nodes of the spatial structure to plane E. The expression of plane E is obtained by solving the equation using the least squares method. The direction of the rotation axis is the direction of the intersection of plane E and the horizontal plane; the rotation angle is the angle between plane E and the horizontal plane.

3. The method for vertically rotating and lifting a large-span space structure according to claim 1 is characterized in that: The ground assembly posture is shaped by the rotation direction and the rotation angle, and the assembly posture after shape finding has the smallest amount of measures for assembling the tire frame.

4. The method for vertically rotating and lifting a large-span space structure according to claim 1 is characterized in that: The ground posture assembly position is determined based on the principle that the horizontal displacement of the rotated assembly posture relative to the design posture is evenly distributed. The spatial structure is formed at this assembly position, and the horizontal displacement of each lifting point from the lifting point is evenly distributed.

5. The method for vertically rotating and lifting a large-span space structure according to claim 1 is characterized in that: The lifting rate of each lifting point is calculated by the change of the lifting rope of each lifting point, and the change of the lifting rope is obtained as a function of the vertical projection distance from the lifting point to the rotation axis.

6. The method for vertically rotating and lifting a large-span space structure according to claim 1 is characterized in that: Limiting measures are taken to prevent the spatial structure from shifting during the lifting process and to ensure that the spatial structure moves along the predetermined trajectory.

7. The method for vertically rotating and lifting a large-span space structure according to claim 6 is characterized in that: The limiting measures are as follows: a chain hoist is installed at the corner of the lifting space structure and the steel column. The chain hoist is in a relatively loose state before it leaves the frame, and is in a slightly tight state after lifting a certain stroke. The chain hand hoist is used to slowly release the horizontal displacement of the space structure to a static free state. The space structure is synchronously lifted to a height greater than the height difference of the grid, and then switched to the asynchronous lifting mode. The hand hoist assists the space structure in completing the posture rotation by releasing the horizontal displacement in steps, and then the hoist is removed.

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