Construction method for installing tower crane by using cable crane

Abstract

The invention discloses a construction method for installing a tower crane by using a cable crane, which comprises the following steps: S1, on a curved surface structure of a main limb of an arch bridge, a steel platform foundation adapted to the radian of an arch body is constructed through a rigid connection node where a tubular support member is attached to the curved surface, and the steel platform foundation transmits the load of the tower crane to the main limb of the arch bridge through a space frame structure; s2, a large-tonnage hoisting device with the span covering the arch span is adopted, tower crane components are sequentially hoisted from the two sides of the arch bridge to the midspan direction, and the hoisting path crosses the complex terrain of the canyon or the river surface; s3, in the multi-tower-crane cross operation area, the height difference and the horizontal operation area interval between the multiple tower cranes are controlled, and a three-dimensional space anti-collision system is constructed in combination with environmental parameter monitoring; and S4, the tower body is jacked in stages, and installation precision control is achieved through real-time perpendicularity monitoring. The advantage that the span of the cable crane is large is utilized, and on-site assembling links are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge engineering construction, in particular to a construction method for installing a tower crane by using a cable crane. BACKGROUND

[0002] In bridge engineering construction, especially in the construction of arch bridges crossing deep valleys and rivers, the installation of a tower crane as a key vertical transportation equipment is significantly more difficult than in ordinary terrains.

[0003] Traditional tower crane installation usually adopts a truck crane or a tower crane for auxiliary hoisting, but in the environment of an arch bridge, the following technical bottlenecks exist: (1) The arch bridge crosses steep and deep valleys, for example, the relative height difference in the area where the Wujiang Super Bridge is located is up to 400 m, and the natural slope is 60-85°. The traditional truck crane is limited by the site flatness and the working radius, and it is difficult to carry out work on the steep mountain or narrow arch platform. Moreover, the hoisting height is insufficient, which cannot meet the requirements of high-pier tower crane installation; (2) The traditional method needs to hoist and assemble components in multiple stages, and the assembly of components relies on temporary supports on site, which has a strong dependence on the site. In the construction of an arch bridge, the components of a tower crane (such as a balance arm and a hoisting arm) are heavy, and the traditional equipment needs to be transported multiple times, which is time-consuming and labor-intensive, and it is difficult to adapt to the rapid construction rhythm of an arch bridge; (3) Multiple tower cranes often need to work together in arch bridge projects. In the existing technology, the collision between multiple tower cranes is mainly controlled by simple height difference, and there is a lack of systematic coordination mechanism for three-dimensional space work in arch bridges. For example, when multiple tower cranes are installed at different pier positions on an arch, the traditional method does not consider the influence of the curvature of the arch bridge on the turning radius of the tower crane, which is prone to collision accidents due to the intersection of work areas; (4) The main limb of an arch bridge is an arc-shaped structure, and the traditional concrete foundation or steel frame foundation cannot be effectively connected with the arch structure, which has the risk of foundation settlement and structural instability; (5) The traditional steel platform foundation adopts an equal-section I-beam, which does not optimize the cross-sectional form according to the stress characteristics of the arch limb, and the connection between the steel pipe column and the arch limb only uses simple welding without setting a stiffener plate to enhance the stiffness of the node, which is prone to problems such as welding seam cracking and steel pipe column tilting under the action of tower crane load. Therefore, in view of the above deficiencies, there is an urgent need for a construction method for arch bridges. SUMMARY

[0004] The present application aims to provide a construction method for installing a tower crane by using a cable crane, which takes advantage of the large span of a cable crane, breaks through the limitations of the terrain of an arch bridge on hoisting equipment, realizes the one-time hoisting and positioning of steel platform foundation components and tower crane components, and reduces the on-site assembly process.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] A construction method for installing a tower crane by using a cable crane, comprising the following steps:

[0007] S1, steel platform foundation construction: on the curved surface structure of the arch bridge main limb, a steel platform foundation is constructed by rigid connection nodes of tubular support members and curved surface fitting, which is adapted to the curvature of the arch body, and the tower load is transmitted to the arch bridge main limb through the space frame structure;

[0008] S2, cable crane positioning and hoisting: a large-tonnage hoisting device covering the arch span is adopted, and the tower components are hoisted from the arch bridge two sides to the midspan direction in sequence, and the hoisting path crosses the complex terrain of the valley or river surface;

[0009] S3, group tower cooperative control: in the multi-tower crane cross operation area, the height difference between the multi-tower cranes and the horizontal operation area interval are controlled, and a three-dimensional space anti-collision system is constructed combined with environmental parameter monitoring;

[0010] S4, group tower anti-collision control: based on tower load distribution and trimming, the tower body is lifted in stages, and the installation precision control is realized through real-time verticality monitoring.

[0011] Optimized, the tubular support member is arranged longitudinally along the arch limb, fixed with the arch limb through the curved surface transition piece, and the stiffener plate is fixed at the node.

[0012] Optimized, the hoisting device is a cable crane system, with a rated lifting capacity of ≥100t and a main cable span of ≥200m, equipped with a multi-lifting point rigging combination for segmented integral hoisting of tower components.

[0013] Optimized, the minimum vertical difference of adjacent tower cranes is ≥10m, and the horizontal operation area interval is ≥5m.

[0014] Optimized, the tower body verticality deviation during the tower crane jacking process is controlled to be ≤2 / 1000.

[0015] Optimized, the curved surface transition piece connection node adopts double-sided welding process, the weld grade is not less than two, the node shear bearing capacity is ≥200kN, and the tensile bearing capacity is ≥500kN.

[0016] The working principle and beneficial effects of the present application are as follows:

[0017] (1) The existing technology steel platform foundation is mostly planar frame, and only simple bolt anchoring is adopted for connection with the arch limb, which is easy to cause foundation inclination due to uneven arch limb curved surface stress. Through curved surface fitting of steel pipe column, stiffener plate reinforced welding and space flat link frame, a "curved surface self-adaptive rigid foundation" is formed, which improves the stability compared with the traditional foundation.

[0018] (2) The cable crane is used for cross-valley hoisting, the single hoisting weight reaches 10.27t, the high-altitude assembly process is reduced by 60%, and the construction period is shortened by 30%.

[0019] (3) In the multi-tower crane cross operation area, control the height difference between the multi-tower crane, the horizontal operation area interval, combined with environmental parameter monitoring, build a three-dimensional space anti-collision system.

[0020] The cable crane has the advantage of large span, which breaks through the limitation of the terrain of the arch bridge on the hoisting equipment, realizes the one-time hoisting of the steel platform foundation component and the tower component, and reduces the on-site assembly link. The steel platform foundation adopts a combined structure of steel pipe column and I-beam, the steel pipe column is arranged in line with the curved surface of the arch limb, the node connection is enhanced by stiffening plate, the foundation load is uniformly transmitted to the arch limb, and the problem of weak connection between traditional foundation and arch structure is solved. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a steel platform foundation diagram of the tower crane;

[0022] Figure 2 is a side view of Figure 1 ;

[0023] Figure 3 is a whole plane layout plan view;

[0024] Figure 4 is a whole plane layout front view. DETAILED DESCRIPTION

[0025] The following will be further described in detail through specific embodiments:

[0026] Embodiment: Wujiang super major bridge is located near Sanchalin village in Weng'an county, Guizhou province, and spans a deep valley between two mountains with extremely steep terrain. The main span spans the Wujiang valley, the ground elevation is 477.85-877.66m, the terrain undulates greatly, the relative height difference is about 400m, the degree is relatively large, and the natural slope is 60-85°. The river surface is 220 meters wide, the water depth is 100 meters, the bridge abutment bedrock is exposed on both sides, the local vegetation coverage is low, and the traffic is inconvenient. The bridge adopts the scheme of the deck type concrete arch bridge, the bridge is connected with Jiangjiehe No. 2 tunnel in front and connected with the roadbed in back.

[0027] According to the project construction plan, three tower cranes are arranged on the arch of Wujiang super major bridge, one tower crane for each of No. 2, No. 5 and No. 8 piers, and the tower crane for No. 2 pier (field number arch No. 1 tower crane) is installed this time. The type of arch No. 1 tower crane is WA7015-10E, the maximum independent height of the tower crane is 60m, the maximum independent height of the tower body is composed of 1 foundation section with a height of 7.5m and 17 standard sections with a height of 3m, the cross section is 2m*2m, the maximum lifting weight is 5t at 2 times, the maximum lifting weight is 10t at 4 times, and the reference Figures 1-4 .

[0028] I. Steel platform foundation construction

[0029] Steps: (1) Positioning and installation of steel pipe columns: Six φ820-8 steel pipe columns (8mm wall thickness) are used and arranged along the longitudinal curved surface of the arch main limb. Three of them are 7.77m long (support leg fixed foundation section) and three are 3m long (standard support columns). The maximum weight of a single column is 4.2t. The steel pipe columns are fixed to the arch main limb by double-sided welded stiffeners (three stiffeners on the front and back of each column, with a weld foot height of ≥15mm and a weld grade of Level 2). I125a I-beams are used to connect the steel pipe columns (with tie plates set at 500mm intervals) to form a spatial frame structure.

[0030] (2) The steel pipe columns and the main limbs of the arch are fixed by double-sided welded stiffening plates (three stiffening plates in front and behind each column, with weld foot height ≥15mm and weld grade 2). I125a I-beams are used to connect the steel pipe columns (with tie plates set at intervals of 500mm) to form a spatial frame structure.

[0031] Installation of the load-bearing frame and beam: A three-piece I163a I-beam load-bearing frame (9.5m long) and a load-bearing beam (5m long) are installed on top of the steel column. They are fully welded together with stiffening plates (weld leg height ≥ 15mm) to form a rigid foundation plane. A saddle plate is installed at the connection between the load-bearing beam and the main arch limb. The weld grade is second-level, and the weld leg height is ≥ 20mm.

[0032] 2. Cable crane hoisting operation

[0033] Tower crane section hoisting: The base section and climbing frame assembly (weighing 10.27t) were hoisted at four points using φ26mm steel wire rope (6×37M-1770, safety factor 8) and 8.5t shackles. The cables were lifted vertically to the steel platform foundation and connected via φ65 pins. Standard sections (5 sections, each weighing 1.61t) were hoisted sequentially using φ20mm steel wire rope. Each section took approximately 30 minutes to hoist, reaching a total height of 24m.

[0034] Superstructure installation:

[0035] The slewing assembly (including the driver's cab, weighing 7.97t) was hoisted using a four-point rigging system (φ26mm steel wire rope) and connected to the tower pin. The pre-tightening torque of the M24 bolts was checked to be 640N·m. The counter-jib was hoisted in sections: The front boom section (3.76t) and the rear boom section (4.78t) were hoisted separately using fixed lifting lugs. After installation, the tie rods were connected to the short tie rod pins. The boom was hoisted in sections: The 70m boom was hoisted in three steps (25m + 22.5m + 22.5m), using the top chord lifting point. Sections 1-3 (5.83t) were hoisted in the first step using φ26mm steel wire rope, and subsequent sections were hoisted using φ20mm steel wire rope.

[0036] 3. Tower crane lifting operation

[0037] Preparation for jacking: the hydraulic pump station is refueled to the specified oil level, the engagement degree of the jacking cross beam and the steps is checked, and the length of the loosened cable is greater than the jacking height (10 m). Balancing calculation: when the arm length is 70 m, the balancing weight is 1.61 t, and the load carrier is located at a range of 12.6 m.

[0038] Implementation of jacking: the hydraulic jacking speed is 0.69 m / min, and jacking is implemented in two times (each time jacking half of the standard section height), the standard section is inserted, and then the connection is implemented by using a φ55 pin shaft, the total jacking height is 9 m, and the final height is 33 m. Verticality monitoring: a theodolite is used, and the verticality deviation of the main chord is less than or equal to 1.5 / 1000.

[0039] Four, group tower anti-collision and safety control

[0040] Height difference setting: the height difference between arch 1 (final 33 m) and arch 2 T6520-10M (final 60 m) is 27 m, and the height difference between arch 1 and arch 3 W7015-10M (final 34.2 m) is 1.2 m, which meets the requirement that the height difference between adjacent towers is greater than or equal to 1.2 m.

[0041] Operation rules: the principle of “low tower yielding to high tower, later tower yielding to earlier tower, and moving tower yielding to static tower” is implemented, a brake device is arranged on the rotating mechanism (the response time is less than or equal to 0.5 s), jacking is prohibited when the wind speed is greater than or equal to 12 m / s, and hoisting is stopped when the wind is greater than or equal to 6.

[0042] In summary, (1) the existing technology steel platform foundation is mostly a plane frame, and only simple bolt anchoring is adopted for connection with the arch limb, which is prone to cause the foundation to tilt due to uneven stress of the curved surface of the arch limb. Through curved surface fitting of the steel pipe column, reinforcement plate enhanced welding and spatial flat link frame, a “curved surface self-adaptive rigid foundation” is formed, which improves the stability compared with the traditional foundation. (2) Cable crane is adopted for cross-valley hoisting, and the single hoisting weight reaches 10.27 t, the high-altitude assembly process is reduced by 60%, and the construction period is shortened by 30%. (3) In the cross operation area of multiple towers, the height difference between multiple towers and the horizontal operation area interval are controlled, and a three-dimensional space anti-collision system is constructed in combination with environmental parameter monitoring.

[0043] The application takes advantage of the large span of the cable crane, breaks through the limitation of the terrain of the arch bridge on the hoisting equipment, realizes one-time hoisting of the steel platform foundation components and tower components, and reduces the on-site assembly link. The steel platform foundation adopts a combined structure of a steel pipe column and an I-beam, the steel pipe column is arranged in fitting with the curved surface of the arch limb, the node connection is enhanced by a reinforcement plate, the foundation load is uniformly transmitted to the arch limb, and the problem of weak connection between the traditional foundation and the arch structure is solved.

[0044] The above-mentioned are only embodiments of the present application, and the common knowledge of specific structures and characteristics in the scheme is not described too much. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, which will not affect the effect and practicality of the patent. The protection scope claimed in this application should be subject to the content of its claims, and the specific implementation mode and the like recorded in the specification can be used to explain the content of the claims.

Claims

1. A construction method for installing a tower crane using a cable crane, characterized in that: The steps include: S1. Steel platform foundation construction: On the curved surface structure of the arch bridge main limb, a steel platform foundation that adapts to the curvature of the arch is constructed through rigid connection nodes where tubular support members fit the curved surface. The steel platform foundation transmits the tower crane load to the arch bridge main limb through a space frame structure. S2. Cable crane positioning and hoisting: Using a large-tonnage hoisting device with a span that covers the arch span, the tower components are hoisted sequentially from both sides of the arch bridge toward the mid-span. The hoisting path crosses the complex terrain of canyons or rivers. S3, Collaborative control of tower cranes: In the cross-operation area of ​​multiple tower cranes, the height difference between the cranes and the horizontal operating area spacing are controlled, combined with environmental parameter monitoring to build a three-dimensional space anti-collision system; S4. Anti-collision control of tower groups: Based on the load distribution and balancing of the tower crane, the tower body is lifted in stages, and installation accuracy is controlled through real-time verticality monitoring.

2. The construction method for installing a tower crane using a cable crane according to claim 1, wherein: The tubular support members are arranged longitudinally along the arch limbs, fixed to the arch limbs via curved transition pieces, and stiffening plates are fixedly provided at the nodes.

3. The construction method for installing a tower crane using a cable crane according to claim 2, wherein: The hoisting device is a cable hoist system with a rated lifting capacity of ≥100t and a main cable span of ≥200m, and is equipped with a multi-hanging point rigging combination for the segmented and integral hoisting of tower structure components.

4. The construction method for installing a tower crane using a cable crane according to claim 3, wherein: The minimum vertical height difference between adjacent tower cranes is ≥10m, and the horizontal operating area interval is ≥5m.

5. The construction method for installing a tower crane using a cable crane according to claim 4, characterized in that: During the tower crane lifting process, the verticality deviation of the tower body is controlled to be ≤2 / 1000.

6. The arch bridge tower crane installation system according to any one of claims 1 to 5, characterized in that: The curved transition piece connection nodes adopt double-sided welding technology, the weld grade is not lower than level 2, the node shear bearing capacity is ≥200kN, and the tensile bearing capacity is ≥500kN.

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