A method for installing, positioning and hoisting a curved steel shell

Abstract

The present application belongs to the technical field of bridge construction, especially to a curve type steel shell installation positioning hoisting method. Step one, construction preparation, the positioning steel support and the first section steel shell are manufactured, assembled and completed, and the acceptance is completed; according to the guide line and the leveling point provided by the design, the guide line re-measurement and the encryption work of the control point are completed, the lofting condition is provided, all the measuring instruments are comprehensively inspected and corrected before construction; according to the spacing between two adjacent steel rods and the requirement of the tension force. The curve type steel shell installation positioning hoisting method can fix the installation table on the positioning steel support through the relative movement of the two limiting frames in the fixing device, and move the positioning device through the offset device as the first section steel shell descends, continuously position the first section steel shell, and then control the first section steel shell to be accurately placed on the positioning steel support and butt-jointed with the positioning steel support, thereby improving the installation efficiency of the first section steel shell.

Description

Technical Field

[0001] This invention relates to the field of bridge construction technology, and in particular to a method for installing, positioning and hoisting curved steel shells. Background Technology

[0002] As a new type of structural system, steel-concrete composite cable towers fully utilize the advantages of steel and concrete. Compared with traditional concrete cable towers, they have advantages such as no need for formwork, rapid installation, beautiful appearance, light structure, and high rigidity. However, the installation of the first section of the steel shell in a curved steel-concrete composite cable tower requires high-precision large-scale hoisting equipment and is greatly affected by the external environment, making on-site construction control difficult. The selection of hoisting equipment, installation accuracy, installation quality control, and construction safety assurance during the on-site installation of the first section of the steel shell are the key challenges of the construction. Therefore, a method for the installation, positioning, and hoisting of curved steel shells is designed. Summary of the Invention

[0003] Based on the existing technical problems of installing the first section of the steel shell of a curved steel-shell concrete cable tower, which requires large hoisting equipment, high installation accuracy, and the steel shell is greatly affected by the external environment, making on-site construction control difficult, this invention proposes a method for installing, positioning, and hoisting curved steel shells.

[0004] The present invention proposes a method for installing, positioning and hoisting a curved steel shell. Step 1: Construction preparation, which involves manufacturing and assembling the positioning steel bracket and the first section of the steel shell, and completing the acceptance test. Based on the traverse and leveling points provided in the design, complete the traverse resurvey and control point densification work, and meet the conditions for setting out. Before construction, conduct a comprehensive inspection and calibration of all measuring instruments. Based on the spacing between two adjacent steel bars and the required tension force, the tensioning jack and auxiliary tooling were designed and manufactured, and the jack calibration was completed. Step 2: Construction of concrete supports. The concrete supports use the same grade of concrete as the foundation concrete. Before pouring, bolt holes for anchor bolts connecting the concrete supports and the positioning steel brackets are reserved. After the concrete supports are poured, water curing is carried out. After the formwork is removed, the concrete supports are roughened around and on top, and the roughening quality is strictly guaranteed. There are a total of 7 sets of concrete supports, two in each set, located directly below the inner and outer wall panels of the first section of steel shell. Step 3: Construction of positioning steel support. After the concrete pier is constructed, the reinforcement of the third layer of the foundation and the pre-embedded reinforcement of the tower base are installed. After the reinforcement is tied, the top layer of the foundation reinforcement is used as a construction platform to install the positioning steel support. Reinforcement that conflicts with the positioning steel support is cut off and reinforced. Step 4: Place the steel bars. After the positioning steel bracket is installed, insert the high-strength steel bars on the positioning steel bracket from top to bottom. Insert the steel bars on the positioning steel bracket into the third layer of foundation steel bars through the steel bar holes on the positioning steel bracket. Also insert the other steel bars into the third layer of foundation steel bars in advance and place them in place to facilitate the subsequent installation of steel bars. Step 5: Set up pad beams and limiting devices. Place pad beams horizontally and vertically in layers on the three outer positioning steel brackets using the gaps between the steel bars. Set up limiting plates on the outside of the positioning steel brackets for the initial positioning of the first section of steel beam. Step Six: Hoist the first section of the steel shell and position it using positioning equipment; Step 7: Steel bar installation. After the first section of the steel shell is placed on the temporary support, the steel bars are manually installed. Since there are many conflicts between the steel bars and the inner wall panels and waterproof panels of the steel shell, the steel bars are installed from bottom to top. Step 8: Lowering and fine-tuning the first section of the steel shell. The positioning device is set on one side of the positioning steel bracket. The positioning device includes a mounting platform and a fixing device for installing the mounting platform and the positioning steel bracket. An offset device for moving the positioning device is fixedly installed on the upper surface of the mounting platform. The fixing device includes a fixing port on one side surface of the mounting platform, and two sets of staggered limiting brackets are slidably inserted into the inner wall of the fixing port; two sets of spiral openings with opposite directions are opened on one end surface of the two limiting brackets; a forward and reverse motor is fixedly installed on the inner wall of one end of the fixing port; and a bidirectional threaded rod that is threaded with the inner wall of the spiral opening is fixedly connected to the main shaft end face of the forward and reverse motor.

[0005] The offset device includes a lateral limiting frame fixed to the upper surface of the mounting platform. A first servo motor is fixedly mounted on one end surface of the lateral limiting frame. A lateral threaded rod, mounted on the inner wall of the lateral limiting frame via a bearing, is fixedly connected to the spindle end of the first servo motor. A connecting block is threaded onto the outer surface of the lateral threaded rod. A vertical limiting frame is fixedly connected to the upper surface of the connecting block. A second servo motor is fixedly mounted on the top of the vertical limiting frame. A vertical threaded rod, mounted on the inside of the vertical limiting frame via a bearing, is fixedly connected to the spindle end of the second servo motor. A sliding table, threaded with the outer surface of the vertical threaded rod, is movably fitted onto the inner wall of the vertical limiting frame.

[0006] The positioning device includes a mounting groove formed on the lower surface of the sliding table, with a positioning platform having a toothed top slidably inserted into the inner wall of the mounting groove; a third servo motor is mounted on the upper surface of the sliding table, and a drive gear is fixedly mounted on the outer surface of the main shaft of the third servo motor. The drive gear meshes with the upper surface of the positioning platform to drive the positioning platform, thereby controlling the positioning platform to reciprocate along the lateral direction of the mounting groove; a laser positioning assembly is fixedly mounted on the lower surface of the positioning platform; a through-hole is formed on one end surface of the positioning platform, and a dual-axis motor is mounted on the inner wall of the through-hole. Deflection columns are fixedly connected to the outer surfaces of both ends of the dual-axis motor, and a deflection positioning assembly is mounted on one end surface of each deflection column. Both the deflection positioning assembly and the laser positioning assembly are composed of diffuse reflection photoelectric switches.

[0007] Step 9: Installation of the bottom anchoring device for the steel bar and pouring of the third-layer foundation; Step 10: Tensioning of steel bars. After the third layer of the foundation reaches the design strength, the high-strength steel bars are tensioned.

[0008] Preferably, the design control accuracy requirements for the precise fixing of the positioning steel bracket in step three are as follows: the longitudinal and transverse parallel deviation of the axis is no greater than ±5mm, the deviation of the positioning steel bracket from the theoretical transverse axis in the transverse direction is no greater than ±2mm, the deviation from the theoretical axis in the longitudinal direction is no greater than ±1mm, the elevation error of the positioning steel bracket is no greater than +5mm, the height difference between two adjacent positioning steel brackets in the transverse direction is no greater than 1mm, and the height difference between two adjacent positioning seats in the longitudinal direction is no greater than 2.4mm. A fine-tuning device for positioning steel supports is installed on the concrete piers. The fine-tuning device is made by pre-embedding steel bars at the corners of each set of concrete piers, with the top of the pre-embedded steel bars 2cm away from the positioning steel supports. Threads are made at the ends of the pre-embedded steel bars, and 7cm long sleeves are screwed on. By screwing the sleeves, the positioning steel supports are raised to precisely adjust the elevation of the four corners of the positioning steel supports, ensuring that the installation accuracy meets the design requirements. After the plane position and the elevation of the four corners of the positioning steel supports are finely adjusted, anchor bolts are installed and the positioning steel supports are fixed with anchor bolts. Then, grouting material is used to fill the 10cm gap between the positioning steel supports and the concrete piers to make them dense.

[0009] Preferably, in step six, the weight of the first steel shell section is 80.3t. Considering the actual situation of the project, a 100t gantry crane is used for hoisting. Before hoisting, the gantry crane needs to be inspected to ensure that it is in good condition. Before hoisting, the lateral position of the gantry crane is moved to the same straight line as the installation of the first steel shell section to reduce the overall movement of the gantry crane after hoisting. The first steel shell section is slowly hoisted down using the 100t gantry crane. During the hoisting process, the positioning equipment positions the steel shell. When it is hoisted to the specified distance, the gantry crane is used for jogging and the hand-operated hoist is used to roughly adjust the plane position of the steel tower. One end of the hand-operated hoist is connected to the bolt hole of the outer wall plate of the steel shell tower, and the other end is connected to the steel cofferdam waler. The hand-operated hoist is set obliquely according to the deviation direction of the first steel shell section.

[0010] Preferably, after all steel bars are installed in step eight, the first section of the steel shell is lifted 5cm by a gantry crane, and the pad beams are removed. After all the pad beams are removed, the interference between the steel bars and the inner wall of the holes of the positioning steel bracket, as well as the surrounding steel bars, is checked. If there is interference, the steel bars are finely adjusted to make the steel bars and the reserved holes of the steel shell centered. Then, the first section of the steel shell is slowly lowered, and the first section of the steel shell is repositioned by the positioning equipment. After the steel shell is slowly lowered to a distance from the positioning steel bracket, the posture of the steel shell is controlled by the coordinates of the corresponding axis point of the positioning bracket and the two points on the large mileage side of the first section of the steel shell segment. A hand-operated hoist is used for precise adjustment to ensure that the plane accuracy control error is <5mm.

[0011] Preferably, after the first section of the steel shell is installed and positioned in step nine, the bottom anchoring device of the steel bar is installed, including channel steel, a 30mm rear steel plate, an anchoring end pad, and an anchoring nut. After all the bottom anchoring devices of the steel bar are installed, the third layer of the foundation is poured. After the pouring is completed, the geotextile is covered and water is sprayed for curing.

[0012] Preferably, in step ten, due to the small spacing between the steel bars, a dedicated steel bar tensioning jack is designed, and tensioning auxiliary tooling, a tensioning stool, is used to tension the steel bars. Before tensioning, the jack needs to be calibrated. The overall tensioning of the steel bars follows the principle of symmetrical tensioning, from large to small, and from the outside to the inside. The steel bars are divided into 4 layers, of which the first and second layers are outer wall steel bars with a diameter of 40mm, and the third and fourth layers are inner wall steel bars with a diameter of 24mm. The tensioning is completed symmetrically first for the first layer of steel bars, and then the tensioning of the second, third, and fourth layers of steel bars is completed in sequence. Each layer of tensioning has 3 working surfaces, and the 3 points are tensioned in the same clockwise direction. When tensioning the first steel bar, the 3 points are performed synchronously, and in subsequent tensioning, attention should be paid to keeping the tensioning speed of the 3 working surfaces synchronized.

[0013] The beneficial effects of this invention are as follows: 1. Successful application ensured the installation accuracy of the first steel tower section, achieving one-time lowering and installation with a plane deviation of ±2mm and a four-corner elevation deviation of ±1mm. At the same time, it blindly passed through 50 anchor rods with a gap of 10mm between the anchor rods and the reserved holes, laying the foundation for the subsequent steel shell installation and demonstrating significant social and economic benefits.

[0014] 2. By setting up a positioning device, the mounting platform can be fixed on the positioning steel bracket by the relative movement of the two limit frames inside the fixing device. As the first section of the steel shell descends, the positioning device is moved by the offset device to continuously position the first section of the steel shell, thereby controlling the first section of the steel shell to be accurately placed on the positioning steel bracket and docked with the positioning steel bracket, thus improving the installation efficiency of the first section of the steel shell. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a curved steel shell installation, positioning, and hoisting method proposed in this invention; Figure 2 This is a top view of a curved steel shell installation, positioning, and hoisting method proposed in this invention; Figure 3 This is a perspective view of the mounting platform structure for a curved steel shell installation, positioning, and hoisting method proposed in this invention. Figure 4 This is a three-dimensional view of the limiting frame structure of the curved steel shell installation, positioning and hoisting method proposed in this invention; Figure 5 This is a perspective view of the bidirectional threaded rod structure of the curved steel shell installation, positioning, and hoisting method proposed in this invention; Figure 6 This is a cross-sectional view of the transverse limiting frame structure of the curved steel shell installation, positioning, and hoisting method proposed in this invention; Figure 7 This is a three-dimensional view of the positioning platform structure of the curved steel shell installation, positioning and hoisting method proposed in this invention; Figure 8 This is a perspective view of the sliding table structure of the curved steel shell installation, positioning and hoisting method proposed in this invention; Figure 9 This is a cross-sectional view of the positioning platform structure of the curved steel shell installation, positioning and hoisting method proposed in this invention; Figure 10 This is a construction process flow diagram of a curved steel shell installation, positioning, and hoisting method proposed in this invention.

[0016] In the diagram: 1. Positioning steel bracket; 2. First section steel shell; 3. Mounting platform; 4. Fixing port; 41. Limiting frame; 42. Spiral port; 43. Forward and reverse motor; 44. Bidirectional threaded rod; 5. Lateral limiting frame; 51. First servo motor; 52. Lateral threaded rod; 53. Connecting block; 54. Vertical limiting frame; 55. Second servo motor; 56. Vertical threaded rod; 57. Sliding platform; 6. Mounting slide; 61. Positioning platform; 62. Third servo motor; 63. Drive gear; 64. Laser positioning group; 65. Through port; 66. Dual-axis motor; 67. Deflection column; 68. Deflection positioning group; 69. Diffuse reflection photoelectric switch; 610. Reflective sticker. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] Reference Figures 1-10 A method for installing, positioning, and hoisting a curved steel shell includes the following steps: Step 1: Construction preparation. The positioning steel bracket 1 and the first section of the steel shell 2 are manufactured, assembled, and inspected. Based on the guide wires and leveling points provided in the design, the guide wires are re-measured and the control points are densified to ensure that the conditions for setting out are met. Before construction, all measuring instruments are thoroughly inspected and calibrated. Based on the spacing between two adjacent steel bars and the tension requirements, the tensioning jacks and auxiliary tooling are designed and manufactured, and the jacks are calibrated.

[0019] Step 2: Construction of concrete supports. The concrete supports use the same grade of concrete as the foundation concrete. Before pouring, bolt holes for anchor bolts connecting the concrete supports and positioning steel bracket 1 are reserved. After the concrete supports are poured, water curing is carried out. After the formwork is removed, the perimeter and top of the concrete supports are roughened, and the roughening quality is strictly guaranteed. There are a total of 7 sets of concrete supports, two in each set, located directly below the inner and outer wall panels of the first section of steel shell 2.

[0020] Step 3: Construction of Positioning Steel Support 1. After the concrete pier construction is completed, the reinforcement of the third layer of the foundation and the pre-embedded reinforcement of the tower base are installed. After the reinforcement is tied, the top layer of the foundation reinforcement is used as a construction platform to install the positioning steel support 1. Reinforcement that conflicts with the positioning steel support 1 is cut off and reinforced. The design control accuracy requirements for the precise fixing of the positioning steel support 1 are as follows: the longitudinal and transverse parallel deviation of the axis is no more than ±5mm; the deviation of the positioning steel support 1 from the theoretical transverse axis in the transverse direction is no more than ±2mm; the deviation from the theoretical axis in the longitudinal direction is no more than ±1mm; the elevation error of the positioning steel support 1 is no more than +5mm; the height difference between two adjacent positioning steel supports 1 in the transverse direction is no more than 1mm; and the height difference between two adjacent positioning seats in the longitudinal direction is no more than 2.4mm.

[0021] A fine-tuning device for positioning steel bracket 1 is installed on the concrete pier. The fine-tuning device is made by pre-embedding steel bars at the corners of each concrete pier, with the top of the pre-embedded steel bars 2cm away from the positioning steel bracket 1. Threads are made at the ends of the pre-embedded steel bars, and a 7cm long sleeve is screwed on. By screwing the sleeve, the positioning steel bracket 1 is raised to precisely adjust the elevation of the four corners of the positioning steel bracket 1, ensuring that its installation accuracy meets the design requirements. After the plane position and the elevation of the four corners of the positioning steel bracket 1 are finely adjusted, anchor bolts are installed and the positioning steel bracket 1 is fixed with anchor bolts. Then, grouting material is used to fill the 10cm gap between the positioning steel bracket 1 and the concrete pier.

[0022] Step 4: Place the steel bars. After the positioning steel bracket 1 is installed, insert the high-strength steel bars on the positioning steel bracket 1 from top to bottom. Insert the steel bars on the positioning steel bracket 1 into the third layer of foundation steel bars through the steel bar holes on the positioning steel bracket 1. Also insert the other steel bars into the third layer of foundation steel bars in advance to facilitate the subsequent installation of steel bars.

[0023] Step 5: Set up pad beams and limiting devices. Place pad beams horizontally and vertically in layers on the three outer positioning steel brackets 1 using the gaps between the steel bars. Set up limiting plates on the outside of the positioning steel brackets 1 for the initial positioning of the first section of the steel shell 2.

[0024] Step Six: Hoisting of the First Steel Shell Section 2. Positioning equipment is used to locate the first steel shell section 2. The first steel shell section 2 weighs 80.3t. Considering the actual project conditions, a 100t gantry crane is used for hoisting. Before hoisting, the gantry crane must be inspected to ensure it is in good condition. Before hoisting, the gantry crane's lateral position is moved to the same straight line as the installation of the first steel shell section 2 to reduce overall movement of the crane after hoisting. The first steel shell section 2 is slowly lowered using the 100t gantry crane. During the lowering process, the positioning equipment is used to position the first steel shell section 2. Once it reaches the designated distance, the gantry crane is used for jogging and the hand-operated hoist is used to roughly adjust the plane position of the steel tower. One end of the hand-operated hoist is connected to the bolt hole on the outer wall of the steel shell tower, and the other end is connected to the steel cofferdam waler. The hand-operated hoist is set at an angle according to the offset direction of the first steel shell section 2.

[0025] Step 7: Steel bar installation. After the first section of steel shell 2 is placed on the temporary support, the steel bars are manually installed. During the installation, due to the numerous conflicts between the steel bars and the inner wall panel and waterproofing plate of the first section of steel shell 2, the steel bars are installed from bottom to top.

[0026] Step 8: Lowering and fine-tuning the positioning of the first steel shell section 2. After all steel bars are installed, lift the first steel shell section 2 by 5cm using a gantry crane and remove the pad beams. After all the pad beams are removed, check the interference between the steel bars and the inner wall of the hole in the positioning steel bracket 1, as well as the surrounding reinforcing bars. If there is interference, make fine adjustments to the steel bars so that the steel bars are centered with the reserved holes in the first steel shell section 2. Then, slowly lower the first steel shell section 2 and reposition it using the positioning equipment. After the steel shell is slowly lowered to a distance from the positioning steel bracket 1, control the posture of the first steel shell section 2 by using the corresponding axis point of the positioning steel bracket 1 and the coordinates of the two points on the large mileage side of the first steel shell section 2. Use a hand-operated hoist for precise adjustment to ensure that the plane accuracy control error is <5mm. The positioning equipment is set on one side of the positioning steel bracket 1. The positioning equipment includes a mounting platform 3 and a fixing device for installing the mounting platform 3 and the positioning steel bracket 1. An offset device for moving the positioning device is fixedly installed on the upper surface of the mounting platform 3.

[0027] like Figures 1-5 As shown, the fixing device includes a fixing port 4 opened on one side surface of the mounting platform 3. In order to install the mounting platform 3 on the positioning bracket, two sets of staggered limit frames 41 are slidably inserted into the inner wall of the fixing port 4. Furthermore, in order to control the two limit frames 41 to move synchronously in opposite directions, two sets of spiral ports 42 with opposite rotation directions are opened on one end surface of the two limit frames 41. Furthermore, a forward and reverse motor 43 is fixedly installed on the inner wall of one end of the fixing port 4. In order to control the movement of the two limit frames 41 simultaneously by the forward and reverse motor 43, a bidirectional threaded rod 44 that is threaded with the inner wall of the spiral port 42 is fixedly connected to the spindle end face of the forward and reverse motor 43. The forward and reverse motor 43 drives the bidirectional threaded rod 44 to control the movement of the two limit frames 41 that are threaded with the bidirectional threaded rod 44. Since the threads on the bidirectional threaded rod 44 have opposite rotation directions, the movement directions of the two limit frames 41 are also opposite.

[0028] like Figures 1-3 and Figures 6-9As shown, the offset device includes a transverse limiting frame 5 fixed to the upper surface of the mounting platform 3. To control the transverse threaded rod 52 to move the connecting block 53, a first servo motor 51 is fixedly mounted on one end surface of the transverse limiting frame 5. The spindle end of the first servo motor 51 is fixedly connected to the transverse threaded rod 52, which is mounted on the inner wall of the transverse limiting frame 5 via a bearing. Furthermore, a connecting block 53 is threaded onto the outer surface of the transverse threaded rod 52. The first servo motor 51 drives the transverse threaded rod 52 to rotate, thereby controlling the connecting block 53. 3. Moving within the horizontal limiting frame 5. Further, in order to control the positioning device to rise and fall, a vertical limiting frame 54 is fixedly connected to the upper surface of the connecting block 53. Further, a second servo motor 55 is fixedly installed on the top of the vertical limiting frame 54. In order to control the sliding table 57 to move within the vertical limiting frame 54, a vertical threaded rod 56 is fixedly connected to the spindle end of the second servo motor 55 and installed inside the vertical limiting frame 54 through a bearing. A sliding table 57 that is threadedly engaged with the outer surface of the vertical threaded rod 56 is movably sleeved on the inner wall of the vertical limiting frame 54.

[0029] like Figures 2-3 and Figures 7-9 As shown, the positioning device includes a mounting groove 6 formed on the lower surface of the sliding table 57. For mounting the positioning table 61, a toothed top is slidably inserted into the inner wall of the mounting groove 6. Furthermore, to control the movement of the positioning table 61 within the mounting groove 6, a third servo motor 62 is mounted on the upper surface of the sliding table 57, and a drive gear 63 is fixedly mounted on the outer surface of the main shaft of the third servo motor 62, causing the drive gear 63 to mesh with the upper surface of the positioning table 61, thereby controlling the positioning table 61 to reciprocate laterally along the mounting groove 6. Further, to position the first section of the steel shell 2, a laser positioning assembly 64 is fixedly mounted on the lower surface of the positioning table 61. Further, to position the first section of the steel shell 2... During the process, the first steel shell 2 is continuously positioned. A through-hole 65 is provided on one end surface of the positioning platform 61, and a dual-axis motor 66 is installed on the inner wall of the through-hole 65. Furthermore, in order to synchronously control the two deflection columns 67, deflection columns 67 are fixedly connected to the outer surfaces of both ends of the dual-axis motor 66. In order to perform real-time positioning during the movement of the first steel shell 2, a deflection positioning group 68 is installed on one end surface of the deflection column 67. Both the deflection positioning group 68 and the laser positioning group 64 are composed of diffuse reflection photoelectric switches. In order to position the first steel shell 2, a reflective sticker 610 is pasted on the circumferential side of the first steel shell 2 parallel to the positioning steel bracket 1. The first steel shell 2 is positioned by the reflection of the infrared light from the diffuse reflection photoelectric switch 69 on the reflective sticker 610.

[0030] By setting up a positioning device, the mounting platform 3 can be fixed on the positioning steel bracket 1 by the relative movement of the two limiting frames 41 inside the fixing device. As the first steel shell 2 descends, the positioning device is moved by the offset device to continuously position the first steel shell 2, thereby controlling the first steel shell 2 to be accurately placed on the positioning steel bracket 1 and docked with the positioning steel bracket 1, thus improving the installation efficiency of the first steel shell 2.

[0031] Step 9: Installation of the bottom anchoring device of the steel bar and pouring of the third layer of the foundation. After the first section of steel shell 2 is installed and positioned, the bottom anchoring device of the steel bar is installed, including the channel steel, the 30mm rear steel plate, the anchoring end pad and the anchoring nut. After all the bottom anchoring devices of the steel bar are installed, the third layer of the foundation is poured. After the pouring is completed, the geotextile is covered and water is sprayed for curing.

[0032] Step 10: Steel Bar Tensioning. After the third layer of the foundation reaches its design strength, the high-strength steel bars are tensioned. Due to the small spacing between the steel bars, a special steel bar tensioning jack is designed, and tensioning auxiliary tooling, tensioning supports, is used to tension the steel bars. The jacks need to be calibrated before tensioning. The overall tensioning of the steel bars follows the principle of symmetrical tensioning, from large to small, and from the outside to the inside. The steel bars are divided into 4 layers. The first and second layers are outer wall plate steel bars with a diameter of 40mm, and the third and fourth layers are inner wall plate steel bars with a diameter of 24mm. The tensioning is completed symmetrically first, and then the tensioning of the second, third, and fourth layers is completed in sequence. Each layer of tensioning has 3 working surfaces. The 3 points are tensioned in the same clockwise direction. When tensioning the first steel bar, the 3 points are tensioned simultaneously. When tensioning the subsequent steel bars, attention should be paid to keeping the tensioning speed of the 3 working surfaces synchronized.

[0033] The successful application ensured the installation accuracy of the first section of steel shell 2, achieving one-time lowering and installation with a plane deviation of ±2mm and a four-corner elevation deviation of ±1mm. At the same time, it blindly passed through 50 anchor rods with a gap of 10mm between the anchor rods and the reserved holes, laying the foundation for the subsequent installation of the steel shell and demonstrating significant social and economic benefits.

[0034] Working principle: The first section of steel shell 2 is 2.5m high, with a cross-sectional dimension of approximately 10m × 10m and a weight of 80.3t. It is hoisted using a 100t gantry crane. After the second-layer foundation is poured, concrete supports are set up, and positioning steel brackets 1 are installed on the concrete supports. Then, high-strength threaded steel bars on positioning steel brackets 1 are inserted into the holes. After completion, the first section of steel shell 2 is hoisted and continuously positioned, with threaded steel bars being inserted. After all the steel bars are inserted, the first section of steel shell 2 is hoisted and placed onto positioning steel brackets 1. Initial positioning is achieved using the limiting plates on positioning steel brackets 1, and then fine-tuning is performed using a hand-operated hoist until the final installation and positioning of the first section of steel shell 2 is completed.

[0035] When positioning the first steel shell 2, the positioning device is initially located at the top of the vertical limiting frame 54. As the first steel shell 2 descends, the deflection column 67 is deflected by the dual-axis motor 66. At the same time, the vertical threaded rod 56 is rotated by the second servo motor 55, causing the sliding table 57 to move within the vertical limiting frame 54. Simultaneously, the first servo motor 51 rotates the horizontal threaded rod 52, controlling the vertical limiting frame 54 to move along the horizontal limiting frame 5 towards the end closer to the positioning bracket, thus performing real-time positioning of the first steel shell 2. When the first steel shell 2 moves to a height of 2m above the ground, the positioning platform 61 is located above the support of the first steel shell 2. The diffuse reflection photoelectric switch 69 inside the laser positioning group 64 and the reflective sticker 610 inside the reserved hole of the first steel shell 2 generate diffuse reflection, thus performing final positioning of the first steel shell 2.

[0036] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for installing, positioning, and hoisting a curved steel shell, characterized in that: Step 1: Construction preparation. The positioning steel bracket (1) and the first section of steel shell (2) are manufactured and assembled, and the acceptance is completed. Based on the traverse and leveling points provided in the design, complete the traverse resurvey and control point densification work, and meet the conditions for setting out. Before construction, conduct a comprehensive inspection and calibration of all measuring instruments. Based on the spacing between two adjacent steel bars and the required tension force, the tensioning jack and auxiliary tooling were designed and manufactured, and the jack calibration was completed. Step 2: Concrete support construction. The concrete support uses the same grade of concrete as the foundation concrete. Before pouring, bolt holes for anchor bolts connecting the concrete support and the positioning steel bracket (1) are reserved. After the concrete support is poured, water curing is carried out. After the formwork is removed, the concrete support is roughened around and on top, and the roughening quality is strictly guaranteed. There are a total of 7 sets of concrete supports, two in each set, located directly below the inner and outer wall panels of the first section of steel shell (2). Step 3, Positioning steel bracket (1) construction: After the concrete support pier construction is completed, the third layer of foundation reinforcement and tower base embedded reinforcement are installed. After the reinforcement is tied, the top layer of foundation reinforcement is used as a construction platform to install positioning steel bracket (1). Reinforcement that conflicts with positioning steel bracket (1) is cut off and reinforced. Step 4: Place the steel bars. After the positioning steel bracket (1) is installed, insert the high-strength steel bars on the positioning steel bracket (1) from top to bottom. Insert the steel bars on the positioning steel bracket (1) into the third layer of foundation steel bars through the steel bar holes on the positioning steel bracket (1). Also insert the other steel bars into the third layer of foundation steel bars in advance and place them in place to facilitate the subsequent installation of steel bars. Step 5: Set up pad beams and limiting devices. Place pad beams horizontally and vertically in layers on the three outer positioning steel brackets (1) using the gaps between the steel bars. Set up limiting plates on the outer side of the positioning steel brackets (1) for the initial positioning of the first section of steel shell (2). Step 6: Hoist the first section of steel shell (2) and use positioning equipment to position the first section of steel shell (2); Step 7: Steel bar installation. After the first section of steel shell (2) is placed on the temporary support, the steel bars are manually installed. When installing the steel bars, since there are many conflicts between the steel bars and the inner wall panel and waterproof board of the first section of steel shell (2), the steel bars are installed from bottom to top. Step 8: Lowering and fine-tuning the positioning of the first section of steel shell (2). The positioning device is set on one side of the positioning steel bracket (1). The positioning device includes a mounting platform (3) and a fixing device for installing the mounting platform (3) and the positioning steel bracket (1). An offset device for moving the positioning device is fixedly installed on the upper surface of the mounting platform (3). The fixing device includes a fixing port (4) opened on one side surface of the mounting platform (3), and two sets of staggered limiting frames (41) are slidably inserted into the inner wall of the fixing port (4). Two sets of spiral openings (42) with opposite directions are opened on one end surface of the two limiting brackets (41). A forward and reverse motor (43) is fixedly installed on the inner wall of one end of the fixed opening (4). A bidirectional threaded rod (44) that is threaded with the inner wall of the spiral opening (42) is fixedly connected to the main shaft end face of the forward and reverse motor (43). The offset device includes a transverse limiting frame (5) fixed on the upper surface of the mounting platform (3). A first servo motor (51) is fixedly mounted on one end surface of the transverse limiting frame (5). A transverse threaded rod (52) mounted on the inner wall of the transverse limiting frame (5) via a bearing is fixedly connected to the spindle end of the first servo motor (51). A connecting block (53) is threadedly sleeved on the outer surface of the transverse threaded rod (52). A vertical limiting frame (54) is fixedly connected to the upper surface of the connecting block (53). A second servo motor (55) is fixedly mounted on the top of the vertical limiting frame (54). A vertical threaded rod (56) mounted inside the vertical limiting frame (54) via a bearing is fixedly connected to the spindle end of the second servo motor (55). A sliding table (57) that is threadedly engaged with the outer surface of the vertical threaded rod (56) is movably sleeved on the inner wall of the vertical limiting frame (54). The positioning device includes a mounting groove (6) formed on the lower surface of the sliding table (57), and a positioning platform (61) with a toothed top is slidably inserted into the inner wall of the mounting groove (6). A third servo motor (62) is mounted on the upper surface of the sliding table (57), and a drive gear (63) is fixedly mounted on the outer surface of the spindle of the third servo motor (62). The drive gear (63) meshes with the upper surface of the positioning platform (61) to drive the positioning platform (61), thereby controlling the positioning platform (61) to move along the mounting groove (6). The positioning platform (61) moves laterally and reciprocates. A laser positioning group (64) is fixedly installed on the lower surface of the positioning platform (61). A through-hole (65) is opened on one end surface of the positioning platform (61). A dual-axis motor (66) is installed on the inner wall of the through-hole (65). A deflection column (67) is fixedly connected to the outer surfaces of both ends of the dual-axis motor (66). A deflection positioning group (68) is installed on one end surface of the deflection column (67). Both the deflection positioning group (68) and the laser positioning group (64) are composed of diffuse reflection photoelectric switches. Step 9: Installation of the bottom anchoring device for the steel bar and pouring of the third-layer foundation; Step 10: Tensioning of steel bars. After the third layer of the foundation reaches the design strength, the high-strength steel bars are tensioned.

2. The method for installing, positioning, and hoisting a curved steel shell according to claim 1, characterized in that: The design control accuracy requirements for the precise fixing of the positioning steel bracket (1) in step three are as follows: the longitudinal and transverse parallel deviation of the axis is no greater than ±5mm, the deviation of the positioning steel bracket (1) from the theoretical transverse axis in the transverse direction is no greater than ±2mm, the deviation from the theoretical axis in the longitudinal direction in the longitudinal direction is no greater than ±1mm, the elevation error of the positioning steel bracket (1) is no greater than +5mm, the height difference between two adjacent positioning steel brackets (1) in the transverse direction is no greater than 1mm, and the height difference between two adjacent positioning seats in the longitudinal direction is no greater than 2.4mm. A fine-tuning device for positioning steel brackets (1) is installed on the concrete support. The fine-tuning device is made by pre-embedding steel bars at the corners of each concrete support, with the top of the pre-embedded steel bars 2cm away from the positioning steel bracket (1), and threading the ends of the pre-embedded steel bars and screwing on a 7cm long sleeve. By screwing the sleeve, the positioning steel bracket (1) is lifted to precisely adjust the elevation of the four corners of the positioning steel bracket (1) to ensure that its installation accuracy meets the design requirements. After the plane position and the elevation of the four corners of the positioning steel bracket (1) are finely adjusted, the anchor bolts are installed and the positioning steel bracket (1) is fixed with the anchor bolts. Then, the 10cm gap between the positioning steel bracket (1) and the concrete support is filled with grout.

3. The method for installing, positioning, and hoisting a curved steel shell according to claim 1, characterized in that: In step six, the first section of steel shell (2) weighs 80.3t. Considering the actual situation of the project, a 100t gantry crane is used for hoisting. Before hoisting, the gantry crane needs to be inspected to ensure that it is in good condition. Before hoisting, the lateral position of the gantry crane is moved to the same straight line as the installation of the first section of steel shell (2) to reduce the overall movement of the gantry crane after hoisting. The first section of steel shell (2) is slowly hoisted down using the 100t gantry crane. During the hoisting process, the positioning equipment positions the steel shell. When it is hoisted to the specified distance, the gantry crane is used to jog and the hand chain hoist is used to roughly adjust the plane position of the steel tower. One end of the hand chain hoist is connected to the high bolt hole of the outer wall plate of the steel shell tower, and the other end is connected to the steel cofferdam waler. The hand chain hoist is set obliquely according to the deviation direction of the first section of steel shell (2).

4. The method for installing, positioning, and hoisting a curved steel shell according to claim 1, characterized in that: After all the steel bars in step eight are installed, the first section of steel shell (2) is lifted 5cm by a gantry crane and the pad beam is removed. After all the pad beams are removed, check the interference between the steel bars and the inner wall of the hole of the positioning steel bracket (1) and the surrounding steel bars. If there is interference, the steel bars are finely adjusted so that the steel bars and the reserved holes of the steel shell are centered. Then the first section of steel shell (2) is slowly lowered. The first section of steel shell (2) is repositioned by the positioning equipment. After the steel shell is slowly lowered to a distance of 1 from the positioning steel bracket, the posture of the first section of steel shell (2) is controlled by the corresponding axis point of the positioning bracket and the coordinates of the two points on the large mileage side of the first section of steel shell (2). The hand-operated hoist is used for precise adjustment to ensure that the plane accuracy control error is <5mm.

5. The method for installing, positioning, and hoisting a curved steel shell according to claim 1, characterized in that: After the first section of steel shell (2) is installed and positioned in step nine, the bottom anchoring device of the steel bar is installed, including channel steel, 30mm back steel plate, anchoring end pad and anchoring nut. After all the bottom anchoring devices of the steel bar are installed, the third layer of the foundation is poured. After the pouring is completed, the geotextile is covered and water is sprayed for curing.

6. The method for installing, positioning, and hoisting a curved steel shell according to claim 1, characterized in that: In step ten, due to the small spacing between the steel bars, a special steel bar tensioning jack is designed, and tensioning auxiliary fixtures such as tensioning stools are used to tension the steel bars. Before tensioning, the jacks need to be calibrated. The overall tensioning of the steel bars follows the principle of symmetrical tensioning, from large to small, and from the outside to the inside. The steel bars are divided into 4 layers. The first and second layers are outer wall plate steel bars with a diameter of 40mm, and the third and fourth layers are inner wall plate steel bars with a diameter of 24mm. The tensioning is completed symmetrically first, and then the tensioning of the second, third, and fourth layers is completed in sequence. Each layer of tensioning has 3 working surfaces. The 3 points are tensioned in the same clockwise direction. When tensioning the first steel bar, the 3 points are carried out synchronously. When tensioning the subsequent steel bars, attention should be paid to keeping the tensioning speed of the 3 working surfaces synchronized.

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