Large-diameter special-shaped steel tower section hoisting and turning-over method

Abstract

The invention discloses a method for hoisting and turning over a large-diameter special-shaped steel tower section, and belongs to the technical field of bridge construction. The method comprises the steps that a transport ship carrying segments is positioned and fixed; a tower crane lifting hook is connected with the lifting belt and the segment lifting lugs; the tower crane is started for lifting, the sections are made to rotate around the bottom turnover tool, in the process, the offset of the gravity centers of the sections and the plumb line of the lifting hook is dynamically tracked through a real-time monitoring system, and a transport ship is fed back and controlled to conduct transverse displacement compensation, so that the gravity center deviation is controlled within a preset threshold value; after the segments are turned over in place, the segments are horizontally rotated and finely adjusted to a preset hoisting angle through symmetrically arranged mechanical traction devices; and finally, the segments are lifted to the safe height and hoisted to the bridge site, and precise installation is completed. Through cooperative operation of the tower crane and the transport ship, active stability control over the turning process of the special-shaped steel tower section is achieved, the technical problems that in a traditional method, instability is prone to occurring, operation is complex, and precision is low are effectively solved, and the method has the advantages of being high in safety, easy and convenient to operate and accurate in positioning.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bridge construction, and particularly relates to a large-diameter special-shaped steel tower segment hoisting and turning-over method. BACKGROUND

[0002] With the vigorous development of modern bridge engineering such as long-span cable-stayed bridges and suspension bridges, special-shaped steel towers have been increasingly widely applied due to their artistic streamline shape and efficient structural stress performance. Such steel towers often present complex geometric characteristics such as spatial distortion and gradually changing cross section. Large-diameter special-shaped steel tower segments have characteristics such as large volume, overweight, structural asymmetry and difficulty in intuitively judging the center of gravity. These characteristics make it necessary to complete the turning-over operation from the horizontal lying state to the vertical installation posture during the on-site installation process after the segment is prefabricated and transported, and this process has become a core challenge restricting the safety, efficiency and accuracy of the entire bridge construction.

[0003] At present, in engineering practice, the traditional method for hoisting and turning over of such large special-shaped components mainly relies on the cooperation of double hooks of a large floating crane, the setting of special turning-over supports or the lifting operation by multiple mobile cranes. These traditional methods gradually expose their inherent limitations and technical defects in practice: first, the accurate center of gravity of the special-shaped segment is a dynamic variable during the turning-over process, and the traditional method lacks effective real-time monitoring and active control means. Only relying on the experience estimation of the operator, the segment is prone to lose control and swing, overturn or even collide violently with the transport ship due to sudden deviation of the center of gravity, and the safety risk is extremely prominent. Secondly, the traditional process has too strong dependence on large auxiliary hoisting equipment or special tools, which not only significantly increases the construction cost, but also faces great challenges in feasibility and coordination in restricted water areas with busy navigation or narrow operation area. Thirdly, the conversion process from laying to standing to accurate installation angle often needs multiple starts and stops and repeated adjustments, and the operation process is complicated, inefficient, and the final installation posture and positioning accuracy are difficult to guarantee stably and reliably.

[0004] Therefore, the present application proposes a large-diameter special-shaped steel tower segment hoisting and turning-over method to at least partially solve the above problems. SUMMARY

[0005] To solve the above problems in the prior art, the present application provides a large-diameter special-shaped steel tower segment hoisting and turning-over method, which solves the technical problems of instability risk caused by difficulty in controlling the dynamic center of gravity during the turning-over process of the large-diameter special-shaped steel tower segment, excessive dependence on large special equipment, difficulty in implementation in restricted water areas, complicated operation and difficulty in ensuring installation accuracy.

[0006] The purpose of the present application can be achieved by the following technical scheme: a large-diameter special-shaped steel tower segment hoisting and turning-over method, comprising the following steps: Step S1: Position the transport ship carrying the main tower segment to the preset docking pile and moor it; the tower crane hook is lowered, and the sling is hung between the hook and the preset roll-over lifting lug on the main tower segment; Step S2: Start the tower lifting hook, and make the sling gradually bear force on one side, so that the main tower segment starts to rotate and roll over around the roll-over tool at the bottom of the main tower segment. In this process, the real-time monitoring system dynamically tracks the offset between the gravity center projection position of the main tower segment and the plumb line of the hook, and compensates for the lateral displacement of the transport ship according to the offset feedback, so that the deviation between the gravity center of the main tower segment and the plumb line of the hook of the tower crane is controlled within a preset threshold. Step S3: After the main tower segment is rolled over to be vertical or reaches a preset posture, the main tower segment is horizontally rotated and finely adjusted on the deck of the transport ship through a set of symmetrically arranged mechanical traction devices, so that the main tower segment reaches a preset installation lifting angle. Step S4: The tower crane vertically lifts the main tower segment to a safety height in the range of 0.3 m to 0.8 m above the installation elevation, and then the large arm of the tower crane is rotated to transport the main tower segment to above the bridge installation position; the main tower segment is lowered, and the precise matching and temporary locking of the main tower segment and the installed segment are completed. Step S5: Repeat steps S1 to S4 to complete the assembly of the entire main tower.

[0007] As a preferred technical solution of the present application, the real-time monitoring system includes a total station or a GNSS positioning device for real-time acquisition of three-dimensional coordinates of the monitoring points on the main tower segment; the feedback control is a closed-loop control, and the central controller automatically calculates and outputs instructions to the propeller of the transport ship according to the offset in step S2 to drive the transport ship to accurately compensate for the lateral displacement.

[0008] As a preferred technical solution of the present application, the roll-over process in step S2 adopts a step loading control, and in the initial lifting stage, the lifting is slowly carried out at a first speed, and after the main tower segment is separated from the deck of the transport ship and stabilized, the lifting is carried out at a second speed higher than the first speed.

[0009] As a preferred technical solution of the present application, the mechanical traction device includes a swivel lug symmetrically welded to the lower side of the main tower segment, and a chain block or a hydraulic jack connected between the swivel lug and a fixed point on the transport ship; by synchronously winding and unwinding the chain blocks on both sides or controlling the stroke of the hydraulic jack, the horizontal rotation and fine adjustment of the main tower segment are realized.

[0010] As a preferred technical solution of the present application, the root of the swivel lug is provided with a stress monitoring sensor for real-time monitoring of the stress of the swivel lug during the rotation and fine adjustment, so as to ensure that the swivel lug is within a safe stress range.

[0011] As a preferred technical scheme of the present application, in step S1, a friction-proof protection pad made of rubber or high polymer is arranged at all contact corners of the sling and the main tower segment.

[0012] As a preferred technical scheme of the present application, in step S2, the turning-over tool is a hinged support fixed on the deck of the transport ship, and the turning-over tool is matched with a pre-set hinged hole at the bottom of the main tower segment to form a rotating pivot for turning over of the main tower segment.

[0013] As a preferred technical scheme of the present application, the hinged contact surface of the turning-over tool is a composite material pad with low friction coefficient, or a rolling bearing is arranged in the hinged contact surface of the turning-over tool.

[0014] As a preferred technical scheme of the present application, in step S4, during lowering of the main tower segment, the preliminary alignment is performed by the guide rod arranged at the bottom of the main tower segment to be installed and the guide sleeve arranged at the top of the installed segment, and the accurate positioning and temporary consolidation are realized by the matching parts arranged around the main tower segment.

[0015] The present application has the following beneficial effects: through the cooperative operation of the transport ship and the tower crane and the real-time monitoring feedback control, the dynamic stability control of the turning-over process of the large-diameter special-shaped steel tower segment is realized, the instability risk caused by the gravity center deviation is effectively avoided, the horizontal rotation fine adjustment is completed by using the mechanical traction device on the transport ship, the dependence on the large special hoisting equipment is reduced, the construction cost is reduced, and the present application is particularly suitable for the limited water area working condition; through the hierarchical loading control, the friction-proof protection and the accurate butt joint device, a complete process operation system is formed, and the operation safety, the construction efficiency and the installation accuracy are significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to facilitate the understanding of those skilled in the art, the present application is further described below with reference to the drawings.

[0017] Figure 1 It is a step flow diagram of the present application.

[0018] Figure 2 It is a main tower elevation diagram of the present application.

[0019] Figure 3 It is a main tower elevation construction diagram of the present application.

[0020] Figure 4 It is another main tower elevation construction diagram of the present application.

[0021] Figure 5 It is a turning-over segment hoisting diagram on the transport ship of the present application.

[0022] Figure 6This is a schematic diagram of the overturning and positioning segment of the present invention being hoisted onto a transport ship.

[0023] Figure 7 This is a top view of the main tower and transport ship of the present invention.

[0024] Figure 8 This is a diagram showing the arrangement of the rotating lifting lug and chain hoist of the present invention.

[0025] In the diagram: 1. Tower crane; 11. Hook; 12. Sling; 2. Main tower segment; 3. Transport ship; 4. Mooring pile; 5. Turning tool; 6. Mechanical traction device; 61. Rotating lifting lug; 62. Chain hoist. Detailed Implementation

[0026] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0027] Please see Figures 1-8 This embodiment provides a method for hoisting and turning large-diameter irregularly shaped steel tower segments. Specific steps include positioning the transport vessel 3, connecting the tower crane, turning the main tower segment 2, horizontal rotation, and final installation. These large-diameter irregularly shaped steel tower segments typically feature complex spatial curvature, gradual cross-sectional changes, and asymmetrical centers of gravity, with diameters ranging from 3 to 10 meters and weights exceeding 100 tons. This invention, through the coordinated operation of the tower crane and the transport vessel 3, combined with a real-time monitoring and feedback control system, ensures the segment remains stable throughout the turning process and controls the center of gravity offset within a preset threshold, such as 50 millimeters. The overall implementation emphasizes safety, efficiency, and precision, making it suitable for complex construction environments such as restricted waterways.

[0028] The large-diameter irregular-shaped steel tower segment hoisting and turning method of this invention mainly includes the overall arrangement of a tower crane 1, a main tower segment 2, a transport vessel 3, and berthing piles 4. The tower crane 1 is preferably a large fixed or floating crane, and its lifting capacity should be determined according to the segment weight and dynamic load, typically not less than 1.5 times the segment weight. The main tower segment 2 is an irregular-shaped steel structure, its cross-section may be circular, elliptical, or a custom curved shape, and the segment length is between 10 and 30 meters. The transport vessel 3 is a flat barge or a dedicated transport vessel 3, equipped with a mooring system and propellers for displacement compensation during the turning process. The berthing piles 4 are pre-installed fixed piles used for precise positioning and mooring of the transport vessel 3. The overall arrangement ensures a stable foundation for the hoisting operation and provides a reliable spatial relationship for subsequent steps.

[0029] Furthermore, during the initial hoisting phase, the main tower segment 2 is horizontally placed on the deck of the transport ship 3, with its bottom connected to the turning fixture 5. The turning fixture 5 is a hinged support structure, fixed to the deck of the transport ship 3, and uses low-friction coefficient composite material pads or rolling bearings to reduce frictional resistance during the turning process. The hook 11 of the tower crane 1 is connected to the turning lug on the main tower segment 2 via a sling 12. The sling 12 is preferably a high-strength synthetic fiber sling 12, whose rated load must meet the segment weight requirements, and rubber or polymer anti-friction protective pads are installed at the edges in contact with the segment to prevent coating damage. After turning into place, the segment is horizontally rotated by a mechanical traction device 6 and finally lifted by the tower crane 1 to the bridge installation position.

[0030] The specific implementation process includes the following steps: Step S1: Positioning and Lifting Preparation of Transport Ship 3 The transport vessel 3 carrying the main tower segment 2 is precisely positioned at the pre-designated mooring bollard 4 and secured using a cable system. The arrangement of the mooring bollard 4 must be calculated based on hydrological conditions and segment dimensions to ensure that the transport vessel 3 is not affected by currents or waves during operation. After positioning, the hook 11 of the tower crane 1 is lowered to an appropriate height above the main tower segment 2, typically 3 to 5 meters from the top of the segment. The sling 12 is accurately suspended between the hook 11 and the turning lug of the main tower segment 2. The turning lug is preferably arranged symmetrically at the segment's center of gravity, and its number is determined based on the segment's shape and load distribution, typically 2 to 4. All contact points between the sling 12 and the main tower segment 2 must be equipped with anti-friction protection devices, such as rubber pads with a thickness of not less than 10 mm, to prevent wear on the segment's coating during lifting. In this step, the sling 12, the lug, and the turning fixture 5 must also be inspected for safety to ensure there are no cracks or deformation defects.

[0031] Step S2: Turning and Dynamic Stabilization of Main Tower Segment 2 The lifting system of tower crane 1 is activated, causing hook 11 to slowly lift at a speed of 0.5 m / min. The sling 12 gradually bears force on one side, and the main tower segment 2 begins to rotate and turn around the turning fixture 5. The turning process employs graded loading control: in the initial lifting stage, the segment is lifted slowly at a first speed, for example, 0.3 m / min. After the segment detaches from and stabilizes on the deck of the transport ship 3, it is then lifted at a second speed at a uniform speed, for example, 0.8 m / min. During the turning process, a real-time monitoring system dynamically tracks the offset between the segment's center of gravity projection position and the plumb line of hook 11. The real-time monitoring system includes a total station or GNSS positioning equipment, with no fewer than three monitoring points deployed on the upper part of the segment, collecting three-dimensional coordinate data at a frequency of 10 times per second. The offset data is fed back to the central controller, which automatically calculates the required displacement compensation for the transport vessel 3 and outputs commands to the propeller of the transport vessel 3, driving the transport vessel 3 to move in the opposite direction at an appropriate speed, such as 0.1 m / s to 0.3 m / s, to ensure that the center of gravity of the segment is always kept on the same vertical line as the hook 11, and the deviation is controlled within a preset threshold, such as 50 mm. The turning fixture 5 serves as a rotation pivot, and its hinged contact surface uses PTFE pads or rolling bearings with a friction coefficient not exceeding 0.1 to reduce turning resistance and avoid local stress concentration in the segment.

[0032] Step S3: Horizontal rotation fine adjustment Once the main tower segment 2 is rotated to a vertical or preset position (e.g., an angle of less than 5 degrees with the vertical plane), the segment is horizontally rotated and fine-tuned on the deck of the transport ship 3 using a mechanical traction device 6 to achieve the preset installation and lifting angle. The mechanical traction device 6 includes slewing lugs 61 symmetrically welded to the lower side of the segment, and chain hoists 62 connecting the slewing lugs 61 to a fixed point on the transport ship 3. Stress monitoring sensors, such as resistance strain gauges, are installed at the root of the slewing lugs 61 to monitor the stress on the lugs in real time, ensuring that it remains within a safe stress range, for example, not exceeding 70% of the material's yield strength. Operators simultaneously raise and lower the chain hoists 62 on both sides, using oblique traction to smoothly rotate the segment at a speed controlled between 1 and 3 degrees per minute. The horizontal rotation angle can be monitored using a total station with an accuracy of ±0.5 degrees. In this step, the arrangement of the rotating lifting lug 61 needs to be based on the segment center of gravity calculation to ensure that there is no eccentric load during the rotation process; the rated load of the chain hoist 62 is not less than 20% of the segment weight to ensure safety redundancy.

[0033] Step S4: Lifting and Precision Installation of Main Tower Segment 2 Tower crane 1 continues lifting operations, vertically raising main tower segment 2 to a safe height of 0.5 meters above the installation elevation, which can be adjusted to a range of 0.3 to 0.8 meters depending on the actual situation. During the lifting process, tower crane 1 rotates smoothly at a speed of 0.5 rpm, transporting the segment to the installation position above the bridge site. When lowering the segment, initial alignment is achieved using guide rods at the bottom of the segment to be installed and guide sleeves at the top of the installed segment. The gap between the guide rods and guide sleeves is designed to be 2 to 5 millimeters to ensure smooth insertion. Subsequently, precise positioning and temporary locking are achieved using matching components set around the segment, such as positioning pins or hydraulic clamping devices. The arrangement of the matching components must be based on the segment interface form, usually no less than 4 sets, with positioning accuracy controlled within ±1 millimeter. After temporary locking, the segment joints are initially tightened with bolts or welded for fixation, completing the segment assembly. In this step, the operation of the tower crane must be coordinated with the measurement system to correct the segment position in real time, ensuring that the installation axis deviation does not exceed the allowable value specified in the standard.

[0034] Step S5: Repeat the operation to complete the main tower assembly. Repeat steps S1 to S4 to complete the assembly of all segments of the main tower. The hoisting and turning of each segment requires parameter adjustments based on its specific shape and weight; for example, asymmetrical segments may require increased monitoring points or optimized lifting lug arrangement. Throughout the assembly process, a quality control system is established to record the turning angle, rotation angle, and installation elevation of each segment, ensuring that cumulative errors are controlled within the design range. After the main tower is assembled, overall geometric dimensions are inspected and non-destructive testing of the connections is performed to ensure structural safety.

[0035] In a preferred embodiment, the real-time monitoring system forms a closed-loop control circuit: the central controller calculates the displacement command of the transport ship 3 based on the offset data using a PID algorithm, and transmits it to the propeller system of the transport ship 3 via a wireless communication module. The propeller response time is no more than 1 second, and the displacement compensation resolution reaches 0.01 meters, thereby achieving high-precision stable control. In addition, the turning tool 5 can be designed as an adjustable support to adapt to the hinge hole size at the bottom of different sections. Its material is preferably Q345B steel, and the surface is treated with anti-corrosion coating. The chain hoist 62 of the mechanical traction device 6 can be replaced with a hydraulic jack, whose stroke control accuracy reaches ±1 mm, suitable for fine adjustment of large or heavy sections.

[0036] In another embodiment, for ultra-high or ultra-heavy segments, such as those weighing over 200 tons, a dual-tower crane operation can be employed. One tower crane acts as the main lifting point, bearing most of the load; the other auxiliary tower crane stabilizes the tail of the segment, preventing excessive bending moments during the overturning process. The lifting speed of the auxiliary tower crane is synchronized with that of the main tower crane, ensuring consistency of action through real-time data sharing. This variant embodiment is particularly suitable for irregularly shaped steel towers with drastic cross-sectional changes, such as structures with a round top and square bottom.

[0037] This invention, through the above-described embodiments, achieves active stabilization and precise positioning during the hoisting and turning process of large-diameter irregular-shaped steel tower segments. Its core advantages lie in: overcoming the reliance on specialized turning equipment in traditional methods through coordinated displacement compensation between the transport vessel 3 and the tower crane; controlling the dynamic center of gravity offset within a threshold range using real-time monitoring and feedback control, thus avoiding instability risks; and simplifying the overall process, reducing multiple attitude adjustments and improving construction efficiency. By optimizing the hoisting process, this invention achieves stable control and precise positioning during segment turning, effectively solving technical problems such as poor stability and complex operation in the hoisting of irregular-shaped steel tower segments, and possesses advantages such as high safety, ease of operation, and precise positioning.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for hoisting and turning over large-diameter irregularly shaped steel tower segments, characterized in that, Includes the following steps: Step S1: Position the transport ship carrying the main tower section to the preset berthing pile and moor it securely; The tower crane hook is lowered, and the sling is suspended between the hook and the pre-set turning lug on the main tower segment; Step S2: Start the tower crane lifting hook to gradually apply force to one side of the sling. The main tower segment begins to rotate and turn around the turning fixture at the bottom of the main tower segment. During this process, the offset between the center of gravity projection position of the main tower segment and the plumb line of the hook is dynamically tracked by the real-time monitoring system. The offset feedback control of the transport ship is used to compensate for the lateral displacement, so that the deviation between the center of gravity of the main tower segment and the plumb line of the tower crane hook is always controlled within the preset threshold. Step S3: After the main tower segment is turned to a vertical or preset position, on the deck of the transport ship, a set of symmetrically arranged mechanical traction devices is used to make a horizontal rotational fine adjustment of the main tower segment so that the main tower segment reaches the preset installation and lifting angle. Step S4: The tower crane vertically lifts the main tower segment to a safe height of 0.3m to 0.8m above the installation elevation. Then, the tower crane's boom rotates to transport the main tower segment to the bridge installation position. The main tower segment is then lowered to complete the precise matching and temporary locking of the main tower segment with the installed segment. Step S5: Repeat steps S1 to S4 to complete the assembly of the entire main tower.

2. The method for hoisting and turning large-diameter irregularly shaped steel tower segments according to claim 1, characterized in that, The real-time monitoring system includes a total station or GNSS positioning device, used to acquire the three-dimensional coordinates of monitoring points on the main tower segment in real time; the feedback control is a closed-loop control, in which the central controller automatically calculates and outputs instructions to the propeller of the transport ship based on the offset mentioned in step S2, driving the transport ship to perform precise lateral displacement compensation.

3. The method for hoisting and turning large-diameter irregularly shaped steel tower segments according to claim 1, characterized in that, The turning process in step S2 adopts graded loading control. In the initial lifting stage, it is slowly lifted at the first speed. After the main tower segment is separated from the deck of the transport ship and stabilized, it is then lifted at a uniform speed at the second speed, which is higher than the first speed.

4. The method for hoisting and turning large-diameter irregularly shaped steel tower segments according to claim 1, characterized in that, The mechanical traction device includes slewing lugs symmetrically welded to the lower side of the main tower segment, and chain hoists or hydraulic jacks connected between the slewing lugs and the fixed point on the transport ship; by synchronously raising and lowering the chain hoists on both sides or controlling the stroke of the hydraulic jacks, the horizontal rotation of the main tower segment can be finely adjusted.

5. The method for hoisting and turning large-diameter irregularly shaped steel tower segments according to claim 4, characterized in that, A stress monitoring sensor is installed at the root of the rotating lug to monitor the force on the rotating lug in real time during the rotation fine-tuning process, so as to ensure that the rotating lug is within the safe stress range.

6. The method for hoisting and turning large-diameter irregularly shaped steel tower segments according to claim 1, characterized in that, In step S1, anti-friction protective pads made of rubber or polymer are provided at all contact points between the sling and the main tower segment.

7. The method for hoisting and turning large-diameter irregularly shaped steel tower segments according to claim 1, characterized in that, In step S2, the turning fixture is a hinged support fixed on the deck of the transport ship. The turning fixture matches the pre-set hinged hole at the bottom of the main tower segment to form a rotational pivot for turning the main tower segment.

8. The method for hoisting and turning large-diameter irregularly shaped steel tower segments according to claim 7, characterized in that, The hinged contact surface of the turning fixture is a composite material pad with a low coefficient of friction, or a rolling bearing is provided in the hinged contact surface of the turning fixture.

9. The method for hoisting and turning large-diameter irregularly shaped steel tower segments according to claim 1, characterized in that, In step S4, during the lowering of the main tower segment, preliminary alignment is achieved by using guide rods set at the bottom of the main tower segment to be installed and guide sleeves set at the top of the installed segment, and then precise positioning and temporary consolidation are achieved by using matching parts set around the main tower segment.

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