Step-by-step expanding and splicing integral hoisting method for polygonal cone-shaped steel truss

Abstract

The invention discloses a multilateral cone steel truss step-by-step expanding and splicing integral hoisting method, and belongs to the technical field of building construction hoisting. According to the force bearing point of the polygonal conical steel truss, a pulling rod is arranged at the hoisting center position of the polygonal conical steel truss and in the direction of each side; the polygonal cone-shaped steel truss comprises a middle rectangular lattice located in the center and a plurality of rows of truss lattices located on each side of the middle rectangular lattice. The middle rectangular grid is spliced on the ground around the central pulling rod, and then the middle rectangular grid is lifted; splicing a first row of truss lattices on each side of the middle rectangular lattice, and then sequentially expanding and splicing subsequent truss lattices while lifting; the whole polygonal cone-shaped steel truss is assembled and the designed elevation of the polygonal cone-shaped steel truss is reached; according to the invention, the problem that the polygonal cone-shaped steel truss is difficult to construct in the hoisting and mounting process due to factors such as site limitation is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of building construction hoisting, and particularly relates to a method for gradually expanding and assembling and integrally hoisting a multi-sided pyramid-shaped steel truss. Background Art

[0002] In recent years, with the aesthetic improvement of building schemes, the shapes of steel truss roofs are complex and diverse, and the supporting spans are increasing, resulting in an increase in the construction difficulty of installation.

[0003] Among them, the cross-shaped bridge structure of the Yuzhao Flying Beam forms a stable support through the combination of stone pillars, brackets, and beam timbers. In modern designs, it can be replaced with lightweight steel structures or concrete frames, which not only retain the lightness of the traditional shape but also improve the structural strength and span adaptability. For example, the Nanyuan building adopts a suspended roof design, which is supported by independent steel columns, creating a visual effect similar to "a flying bird spreading its wings". Combining modern materials (such as glass and light-transmitting composite materials) with the open structure of the Yuzhao Flying Beam can enhance the lighting efficiency of the roof. Similar to the principle of expanding the lighting surface through the roof curve in the eave design, the cross-shaped layout of the Yuzhao Flying Beam can naturally introduce multi-directional light, reducing the need for artificial lighting.

[0004] However, during the construction and installation process of this type of multi-sided pyramid-shaped steel truss, difficulties are often encountered due to the limitations and impacts of the installation site. Especially when the main structure and secondary structure around the daylighting roof have been completed, and the installation operation site is located in the middle courtyard position of the building, it is difficult for conventional lifting machinery to enter the site due to the relatively enclosed location. If the method of erecting a scaffolding is adopted, the construction period is long, the measure cost is high, and the cost performance is low. Summary of the Invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a method for gradually expanding and assembling and integrally hoisting a multi-sided pyramid-shaped steel truss, solving the problem that it is difficult to construct the multi-sided pyramid-shaped steel truss during the hoisting and installation process due to factors such as site limitations.

[0006] The present invention is realized through the following technical solutions: A method for gradually expanding and assembling and integrally hoisting a multi-sided pyramid-shaped steel truss, comprising the following steps: Step 1, according to the stress points of the multi-sided pyramid-shaped steel truss, set up a gin pole at the central position of the hoisting of the multi-sided pyramid-shaped steel truss and in the direction of each side; the gin pole is fixed by guy ropes and kept vertical; a pulley block is arranged at the top of the gin pole; Step 2: The multi-sided pyramid-shaped steel truss includes an intermediate rectangular grid at the center and multiple rows of truss grids on each side of the intermediate rectangular grid. Starting from the intermediate rectangular grid as the initial unit, assemble the intermediate rectangular grid around the central derrick on the ground. After assembly, lift the intermediate rectangular grid through the steel wire ropes and the pulley block on the central derrick. Step 3: Assemble the first row of truss grids on each side of the intermediate rectangular grid, and use the derricks set in each side direction as auxiliary lifting points to lift the intermediate rectangular grid and the first row of truss grids. Step 4: Continue to assemble the second row of truss grids on the first row of truss grids, and gradually adjust the lifting points to ensure that the overall center of gravity of the multi-sided pyramid-shaped steel truss is always located at the structural center and the loads of each derrick and lifting point are in balance. Then lift the intermediate rectangular grid, the first row of truss grids, and the second row of truss grids as a whole. Step 5: Repeat Step 4 to expand and lift the remaining truss grid sides while assembling until the assembly is completed to form the multi-sided pyramid-shaped steel truss, and at the same time hoist the entire multi-sided pyramid-shaped steel truss to the design elevation.

[0007] Further, an electric winch is provided outside the derrick, and a guide pulley is provided on the derrick. One end of the steel wire rope of the pulley block passes through the guide pulley at the bottom along the derrick and is connected to the electric winch; the other end of the steel wire rope is connected to the intermediate rectangular grid or the truss grid.

[0008] Further, in Step 1, each derrick is composed of two sections connected together. First, hoist the first section of the derrick, set the middle guy ropes at the top of the first group of the first section of the derrick, and adjust the first section of the derrick to be vertical through the middle guy ropes; then install the second section of the derrick on the first section of the derrick.

[0009] Further, the first section of the derrick and the second section of the derrick are connected by a flange; set the top guy ropes at the top of the second section of the derrick, and adjust the second section of the derrick to be vertical through the top guy ropes.

[0010] Further, concrete structural columns are evenly distributed outside the derricks in the direction of each side, and each derrick corresponds to two concrete structural columns; the ends of the middle guy ropes and the top guy ropes are connected to the concrete structural columns.

[0011] Further, when the truss grid is hoisted to the position of the middle guy ropes, gradually adjust each middle guy rope from above the concrete structural column to below the concrete structural column, and adjust the middle guy ropes one by one in replacement, that is, set the new middle guy ropes below the concrete structural column and then remove the original ropes. After the adjustment of the middle guy ropes is completed and reliably fixed, continue the hoisting.

[0012] Furthermore, the multi-sided pyramid-shaped steel truss is hoisted integrally to the designed elevation and aligned with the corresponding supports which have been fixed to the surrounding structures. Adjust the position of the multi-sided pyramid-shaped steel truss, slowly place it in position while aligning with the supports, and complete the fixation and welding of the multi-sided pyramid-shaped steel truss and the supports.

[0013] Furthermore, after the multi-sided pyramid-shaped steel truss and the supports are fixedly welded, other accessories on the multi-sided pyramid-shaped steel truss are installed using the on-site tower crane.

[0014] Furthermore, first install fixed lifting points at the four corners of the middle rectangular grid. After the installation of the lower row of truss grids is completed, connect the two ends of the outer edge of the lower row of truss grids to the lifting points at the top of the corresponding gin poles on each side through steel wire ropes, and then cancel the lifting points on the upper row of truss grids while keeping the lifting points in the middle rectangular grid.

[0015] The beneficial effects of the present invention compared with the prior art are as follows: 1. According to the actual on-site situation, the present invention adopts the construction method of "fabricating in sections at the factory and hoisting integrally with multi-point gin poles on-site", which ensures the construction progress, project quality and construction safety.

[0016] 2. The method of the present invention has reasonable processes, is safe and reliable during the construction process, the steel truss is balanced and stable during the lifting process, the alignment error of the daylighting roof is small and easy to control. It effectively guarantees the construction quality and speeds up the project progress.

[0017] 3. The present invention solves the technical problem that the hoisting operation is located in the middle of the main body, the position is relatively enclosed and conventional lifting equipment cannot be used, and has the technical benefits of reform and innovation.

[0018] 4. The gin poles adopted by the present invention are convenient to enter the site, the installation and demolition construction are simple, the construction period is short, and the site utilization rate is high. The gin poles are fixed to the structural columns through guy ropes, the landing nodes of the members are reasonably arranged, and the overall stability is high. The multi-point gin pole setting method is beneficial to controlling the height difference between the lifting points and has high safety performance. And the present invention utilizes the principle of the movable pulley to save effort, is tractioned by an electric winch, has low energy consumption and high lifting efficiency. The synchronous guarantee measures for the integral hoisting are efficient, convenient, easy to organize and have good control effect. Description of the Drawings

[0019] Figure 1 is the process flow chart of the method described in the embodiment; Figure 2 is the position positioning diagram of the gin poles described in the embodiment; Figure 3 is the partial structural schematic diagram of the gin poles described in the embodiment; Figure 4 is the installation schematic diagram of the first group of gin poles and the middle guy ropes described in the embodiment; Figure 5Schematic diagram of the installation of the second set of derricks and the top guy ropes described in the embodiment; Figure 6 Schematic diagram of the structure of the traction system described in the embodiment; Figure 7 On-site positioning diagram of the electric winch described in the embodiment; Figure 8 Schematic diagram of the ground assembly of the middle square part described in the embodiment; Figure 9 Schematic diagram of assembling the first row of truss grids and setting auxiliary lifting points; Figure 10 Schematic diagram of assembling the second row of truss grids and installing the inner lifting points of the circumferential derricks; Figure 11 Schematic diagram of assembling the third row of truss grids and installing the outer lifting points of the circumferential derricks; Figure 12 Schematic diagram of completing the assembly of the fourth row of truss grids around the perimeter; Figure 13 Schematic diagram of the seat in place and the completion of the installation of other accessories; In the figure: 1 is the derrick, 2 is the middle guy rope, 3 is the truss grid, 4 is the concrete structural column, 5 is the pulley block, 6 is the electric winch, 7 is the middle rectangular grid, 10 is the lifting lug, 11 is the steel plate, 12 is the steel pipe, 13 is the top guy rope, 14 is the guide pulley, 15 is the steel wire rope, 16 is the seat. Detailed implementation manners

[0020] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail in combination with the embodiments and the drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. The technical solutions of the present invention will be described in detail below in combination with the embodiments and the drawings, but the protection scope is not limited by this.

[0021] This embodiment proposes a method for gradually expanding and assembling and integrally hoisting a multi-sided pyramid-shaped steel truss; The situation of the project to which this method is applied is as follows: The plane structure form of the daylighting roof is an octagonal steel structure, the elevation is conical, and the structure is all made of Q355C rectangular steel pipes welded. The spans in the north-south and east-west directions are both 45.4 m, and the maximum arch in the middle of the span is 9.8 m. There is a rectangular grid in the middle of the daylighting roof, and four truss grids 3 extend obliquely downward from the four sides respectively, forming the shape of a fishpond flying beam.

[0022] Since the main structure around the skylight has been completed, and the installation site is located in the middle of the building, the location is relatively closed, and it is difficult for conventional lifting machinery to enter the site. If the scaffolding method is used, the construction period is long, the cost of measures is high, and the cost performance is low. According to the actual situation and structural form on site, a polygonal cone steel truss step-by-step expansion and assembly overall lifting method proposed in this embodiment is selected, and "factory segmented production and on-site five-point pull-rod overall lifting" is implemented.

[0023] The process principle of the above-mentioned method for gradually expanding and assembling the polygonal conical steel truss as a whole is as follows: According to the modeling characteristics of the Uonuma flying beam, after force calculation, a pull rod 1 is set at the center of the third row of truss grids 3 in the middle and four directions, with a total of 5 pull rods 1. The pull rod 1 is installed in a segmented assembly manner, and the pull rod 1 is fixed to the concrete structure column 4 by a cable wind rope. A pulley block 5 is set on the top of the pull rod 1, and the labor-saving feature of the movable pulley is utilized to lift it under the traction of the electric winch 6. The steel truss is assembled on the ground with the middle rectangular grid 7 as the starting unit. Every time the hoisting truss is lifted by 2 meters, a truss grid 3 is assembled in four directions, and the position of the lifting point is adjusted. After the ground assembly is completed, each electric winch 6 is controlled to work synchronously until the overall lifting is completed (see Figure 1 ).

[0024] A method for hoisting a polygonal conical steel truss by gradually expanding and assembling it; the specific construction steps are: Step 1: Setting the pull rod 1 According to the shape characteristics of the Uonuma flying beam, after force calculation, a pull rod 1 is set at the center of the third row of truss grids 3 in the middle and in each direction (see Figure 2 ), the middle pull rod 1 is 38.4m high, and the 4 pull rods 1 around are 34m high. Four cable rope fixing holes and two lifting ears 10 are set at the top of the pull rod 1. The lifting ears 10 are connected to the pulley block 5 at the head of the pull rod 1. The pulley block 5 model is a 4-door pulley block. (See Figure 3 ).

[0025] Step 2: Install the pull rod 1 The pull rod installation adopts the method of "ground assembly and group hoisting". Each pull rod 1 is evenly divided into 6 sections, each section is about 6 meters long, and every 3 sections form a hoisting unit on the ground for hoisting. The pull rod 1 is assembled by welding.

[0026] Use a tower crane to install the first group of pull rods 1 (19m high), set the middle cable wind rope 2 on the top of the first group of pull rods 1, and tie the ends of the middle cable wind rope 2 to the surrounding concrete structural columns 4 (the concrete structural columns 4 are located outside the pull rods 1, each pull rod 1 corresponds to two concrete structural columns 4, and there are 8 concrete structural columns 4 in total). Adjust the pull rods 1 of the first group to be vertical and tighten the middle cable wind rope 2 (see Figure 4 ).

[0027] With the cooperation of a tower crane, install the second group of derricks 1. The connection method between the upper and lower two groups is flange connection. The flange installation platform uses a knuckle boom aerial work platform. Set the top guy wire 13 at the top of the second group of derricks 1. The end of the top guy wire 13 is tied to the surrounding concrete structural column 4. Adjust the derrick 1 to be vertical and tension the top guy wire 13 (see Figure 5 ).

[0028] Step 3: Set up the traction system One end of the steel wire rope 15 of the pulley block 5 passes through the bottom guide pulley 14 along the derrick 1 and is connected to the electric winch 6 (see Figure 6 ). The other end of the steel wire rope 15 is connected to the truss structure to be lifted; Select a 5-ton electric winch 6. The electric winches 6 must be of the same model, the same batch, and have the same technical parameters. There are 10 electric winches 6 on site, which are distributed around the site, and ensure that the electric winches 6 are not within the projection range of the hoisted components. In this embodiment, six electric winches 6 are arranged in the left and right directions respectively, and two electric winches 6 are arranged in the front and rear directions respectively (see Figure 7 ).

[0029] Step 4: Assemble the truss on the ground Use the middle rectangular grid 7 as the starting unit for truss assembly. Gradually lift the truss according to the assembly progress. Assemble one rectangular unit symmetrically outward each time, and gradually adjust the lifting points of the structure to ensure that the overall center of gravity of the truss is always located at the center of the structure, and the loads of each derrick 1 and the lifting points are in a balanced state. Specifically: The first step: Assemble the middle rectangular grid 7 around the middle derrick 1 on the ground. After assembly, connect the lifting points on the middle derrick 1 (see Figure 8 ); The second step: Use the electric winch 6 to cooperate with the middle derrick 1 to lift the middle rectangular grid 7 by about 2m. Assemble the first row of truss grids 3 on the four sides of the middle rectangular grid 7, and set auxiliary lifting points using the surrounding 4 derricks 1. The auxiliary lifting points only play an auxiliary role to ensure the stability of the structure during hoisting (see Figure 9 ); The third step: Continue to assemble the second row of truss grids 3 on the first row of truss grids 3 around. Install lifting points inside the surrounding 4 derricks 1. Connect the two ends of the outer edge of the second row of truss grids 3 to the lifting points inside one of the corresponding outer derricks 1 through guy wires, and then cancel the auxiliary lifting points (see Figure 10 ); The fourth step: Continue to lift. According to the operation of the third step, complete the assembly of the third row of truss grids 3 around, and install the lifting points outside the circumferential derricks 1 (see Figure 11 ). After hoisting to the middle platform position of the patio, according to the operation of the third step, carry out the assembly of the fourth row of truss grids 3 (seeFigure 12 ).

[0030] Pay attention to the adjustment of the middle guy rope 2: when the component is hoisted to the position of the middle guy rope 2, adjust the middle guy rope 2 from above the concrete structure column 4 to below the concrete structure column 4 one by one. The middle guy rope 2 must be replaced one by one, that is, the original rope can only be removed after the new middle guy rope 2 is set under the concrete structure column 4. It must not be removed first and then installed. Continue hoisting after the middle guy rope 2 is adjusted and securely fixed.

[0031] Step 5: hoist the truss as a whole to the designed elevation. According to the axis position and elevation of the support 16, install the support 16 to the designed position of the surrounding structure, and align the truss as a whole with the corresponding support 16. Adjust the truss position, align the support 16 and slowly put it in place, and complete the fixing and welding of the truss and support 16. After the support 16 is in place and confirmed to be correct, use the on-site tower crane to install other accessories of the conical roof (see Figure 13 ).

[0032] Step 5: Remove the pull rod 1 After the structure is installed, the pull rod 1 is dismantled in sections using a site tower crane with an electric capstan 6 and a steel wire rope 15. The operating platform uses a crank-type aerial work vehicle.

[0033] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the present invention, which should be regarded as belonging to the present invention and the scope of patent protection determined by the submitted claims.

Claims

1. A method for hoisting a polygonal conical steel truss by gradually expanding and assembling it as a whole, characterized in that: The following steps are involved: Step 1: According to the stress points of the polygonal conical steel truss, a pull rod (1) is arranged at the center position of the polygonal conical steel truss hoisting and in the direction of each side; the pull rod (1) is fixed and kept vertical by a guy rope; a pulley block (5) is arranged at the top of the pull rod (1); Step 2: The polygonal conical steel truss includes a middle rectangular grid (7) located in the center, and multiple rows of truss grids (3) located on each side of the middle rectangular grid (7); taking the middle rectangular grid (7) as a starting unit, the middle rectangular grid (7) is first assembled on the ground around the central pull rod (1); after the assembly is completed, the middle rectangular grid (7) is lifted by the steel wire rope (15) and the pulley block (5) on the central pull rod (1); Step 3: assemble the first row of truss grids (3) on each side of the middle rectangular grid (7), and use the pull rods (1) provided in the direction of each side as auxiliary lifting points to lift the middle rectangular grid (7) and the first row of truss grids (3); Step 4: Continue to assemble the second row of truss grids (3) on the first row of truss grids (3), and gradually adjust the hanging points to ensure that the overall center of gravity of the polygonal cone steel truss is always located at the center of the structure, and the loads of each pull rod (1) and the hanging point are in a balanced state; then, the middle rectangular grid (7), the first row of truss grids (3) and the second row of truss grids (3) are lifted as a whole; Step 5: Repeat step 4 to expand and assemble the remaining truss grids (3) while lifting them until the polygonal cone steel truss is assembled and the entire polygonal cone steel truss is hoisted to the designed elevation.

2. The method for hoisting a polygonal conical steel truss by gradually expanding and assembling it as a whole according to claim 1, characterized in that: An electric capstan (6) is arranged on the periphery of the pull rod (1), and the pull rod (1) is provided with a guide wheel (14); one end of a steel wire rope (15) of the pulley block (5) passes through the guide wheel (14) at the bottom along the pull rod (1) and is connected to the electric capstan (6); the other end of the steel wire rope (15) is connected to the middle rectangular grid (7) or the truss grid (3).

3. The method for hoisting a polygonal conical steel truss by gradually expanding and assembling it as a whole according to claim 1, characterized in that: In step 1, each pull rod (1) is composed of two connected sections; first, the first section of the pull rod (1) is hoisted, and a middle guy rope (2) is set at the top of the first group of the first section of the pull rod (1), and the first section of the pull rod (1) is adjusted to be vertical through the middle guy rope (2); then, the second section of the pull rod (1) is installed on the first section of the pull rod (1).

4. The method for hoisting a polygonal conical steel truss by gradually expanding and assembling it as a whole according to claim 3, characterized in that: The first section of the pull rod (1) and the second section of the pull rod (1) are connected by flanges; a top guy rope (13) is arranged on the top of the second section of the pull rod (1), and the second section of the pull rod (1) is adjusted to be vertical by the top guy rope (13).

5. The method for hoisting a polygonal conical steel truss by gradually expanding and assembling it as a whole according to claim 4, characterized in that: Concrete structural columns (4) are evenly distributed around the pull rods (1) in the direction of each side, and each pull rod (1) corresponds to two concrete structural columns (4); the ends of the middle guy rope (2) and the top guy rope (13) are connected to the concrete structural columns (4).

6. The method for integrally hoisting a polygonal conical steel truss by step-by-step expansion and assembly according to claim 5, characterized in that: When the truss grid (3) is hoisted to the position of the middle guy rope (2), the middle guy ropes (2) are adjusted one by one from above the concrete structure column (4) to below the concrete structure column (4). The middle guy ropes (2) are adjusted and replaced one by one, that is, after a new middle guy rope (2) is set below the concrete structure column (4), the original rope is removed. After the middle guy rope (2) is adjusted and securely fixed, the hoisting is continued.

7. The method for integrally hoisting a polygonal conical steel truss by step-by-step expansion and assembly according to claim 1, characterized in that: The polygonal conical steel truss is hoisted as a whole to the design elevation and aligned with the corresponding support (16). The support (16) has been fixed on the surrounding structure. The position of the polygonal conical steel truss is adjusted and aligned with the support (16) and slowly put into place, and the fixing and welding of the polygonal conical steel truss and the support (16) are completed.

8. The method for integrally hoisting a polygonal conical steel truss by step-by-step expansion and assembly according to claim 7, characterized in that: After the polygonal cone steel truss and the support (16) are fixed and welded, other accessories on the polygonal cone steel truss are installed using an on-site tower crane.

9. The method for hoisting a polygonal conical steel truss by step-by-step expansion and assembly as claimed in claim 1, characterized in that: First, fixed hanging points are installed at the four corners of the middle rectangular grid (7). After the installation of the next row of truss grids (3) is completed, the two ends of the outer edge of the next row of truss grids (3) are connected to the top hanging points of the pull rods (1) corresponding to each side through steel wire ropes, and then the hanging points on the previous row of truss grids (3) are cancelled, and the hanging points of the middle rectangular grid (7) are always retained.

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