CN112523413B - Detachable reset design method of bucket screen applied in large-span cable dome structure - Google Patents

Abstract

The invention discloses a detachable reset design method for a bucket screen applied in a large-span cable dome structure. During the disassembly and reset process of the bucket screen, a pulley block, a prestressed cable and a traction device are used. In the disassembly step of the bucket screen, a buffer pad is arranged , Control the pulling force of the traction device, so that the pulling force applied to the prestressed cable is equal to the weight of the bucket screen transferred to the buffer pad. It is added to the sum of the weight of each movable pulley to ensure that the load of each bucket screen hanging point on the cable dome remains unchanged. The cable members of the cable dome structure are less affected by the force during the disassembly and reset process of the bucket screen of the present invention, and the use safety of the cable dome structure building is guaranteed.

Description

Detachable reset design method of bucket screen applied in large-span cable dome structure

technical field

The invention relates to the disassembly and installation technology of large-scale bucket screens in the construction field of stadiums and the like, in particular to a detachable reset design method of bucket screens applied in large-span cable dome structures.

Background technique

In recent years, LED display technology has been continuously innovated and its application range has been continuously expanded. Among them, the hanging bucket-shaped display screen in the center of the large stadium can create a hot arena atmosphere, and it can also bring advertising revenue to the venue. It has become the mainstream of new display device applications in large stadiums at home and abroad. At present, most of the stadium structure systems that use suspended bucket screens are dominated by rigid steel roof component systems, such as grid structure, reticulated shell structure, truss structure and string-supported dome structure. It is extremely rare to use bucket screens in China, and the related installation and disassembly design methods of bucket screens used in flexible structures are even rarer. In the construction process of the actual cable dome structure, the cable members are first stretched, and the prestress is generated by the tension to form the rigidity and shape necessary for the structural bearing, and then the construction of the metal roof and the decoration ceiling is carried out, and finally the hoisting of the bucket screen device is carried out. construction. The bucket screen needs to be dismantled in the later stage of bucket screen maintenance. However, due to the limitation of its structural characteristics, the cable dome structure system is more sensitive to the internal force of the cable members. During the disassembly and maintenance process of the heavy bucket screen, it is easy to cause the internal force of the cable members to change. It may lead to the relaxation of part of the cable and the redistribution of the cable force. When the cable dome is installed after the repair, the cable force is different from the internal force in the design stage, which may threaten the safety of the entire cable dome structure.

In the construction process, in order to avoid the redistribution of cable force caused by dismantling, the method of hanging sandbags and other counterweights is usually adopted to be equivalent to the weight of the bucket screen device. However, the actual installation and disassembly process has a sequence, and it is difficult to ensure that the weight of the hoisted bucket screen and the additional counterweight to be removed are synchronously equivalent, which will inevitably lead to changes in the cable force and this kind of construction that relies on manpower high-altitude operation. Security and work efficiency are low. In addition, it is common to disassemble and maintain the heavy bucket screen on the horse track above the stadium or set up a special lifting maintenance platform, which belongs to the scope of high-altitude operation and a one-time unloading process, which cannot guarantee personal safety and easily causes internal forces on roof components. Variations, and additionally for extra heavy bucket screens such as 30 or 40 tons, it is difficult to find counterweights of such weight and requires large mechanical equipment to be hoisted to the replacement location. Therefore, it is very necessary to devise a design method for the detachable and reassembly of the overweight bucket screen, which has less influence on the force of the cable members in the cable dome structure, and is safe and convenient.

SUMMARY OF THE INVENTION

The invention provides a detachable reset design method for a bucket screen applied in a large-span cable dome structure, which can provide a reference basis for the installation and disassembly of the bucket screen in a related flexible tension cable structure system containing the bucket screen.

For achieving the above object, the present invention adopts the following scheme:

The detachable reset design method of the bucket screen applied in the large-span cable dome structure. The disassembly process of the bucket screen includes the following steps:

Disassembly step (1): install a set of pulley blocks on each bucket screen hanging point of the cable dome structure, each pulley block includes two fixed pulleys and two movable pulleys that are fixed in one, and the fixed pulleys are connected to the hanging pulleys. At the point, the two movable pulleys are connected below the corresponding fixed pulleys, and a prestressed cable is set, so that one end of the prestressed cable is fixedly connected to the ground anchor embedded in the site below the bucket screen, and the other end passes through the diffusion plate. Dispersed into a plurality of cables, the dispersed cables are respectively connected to the hooks at the lower end of one movable pulley in each pulley group, and the hooks at the lower end of the other movable pulley of the pulley group are correspondingly connected to a suspension point of the bucket screen. Each movable pulley of the pulley block is connected with a traction device;

Dismantling step (2): pre-place a buffer pad on the field below the bucket screen, and lower each movable pulley connected to the bucket screen through the traction device, so that the bucket screen is lowered, and the surface of the buffer pad is not yet in contact with the bucket screen. When the critical state of unloading begins, the movable pulley connected to the bucket screen gradually removes the weight of the bucket screen attached to the movable pulley, transfers the weight of the bucket screen to the buffer pad, and at the same time tightens the pulley block through the traction device. The other movable pulley of the pulley controls the pulling force of the traction device, so that the pulling force applied to the prestressed cable is equal to the weight of the bucket screen transferred to the buffer pad;

Disassembly step (3): After the bucket screen is completely removed, the hook of the movable pulley connected to the bucket screen is separated from the suspension point of the bucket screen, and the movable pulley connected with the prestressed cable remains stationary, so that the prestressed pulley is pulled. The cable load is equivalent to the load of the bucket screen weight;

The installation process of Dopping screen reset includes the following steps:

Reset step (1): lower the vacant moving pulleys in the pulley block for connecting with the bucket screen, and connect each suspension point of the bucket screen to the lower end hooks of the lower moving pulleys;

Resetting step (2): gradually tighten the movable pulley connected to the bucket screen through the traction device, and the movable pulley gradually adds part of the weight lifted by the bucket screen. The movable pulley connected with the cable makes the pulling force of the prestressed cable unloaded equal to the sum of the weight of each movable pulley during the lifting of the bucket screen;

Resetting step (3): After the bucket screen is completely lifted, the movable pulley connected to the bucket screen is gradually raised to a specified height, and then the hanging point of the bucket screen is connected to the hanging point of the cable dome structure, and the After the movable pulley connected with the stress cable is gradually lowered to the ground, the prestressed cable is removed.

The present invention also has the following preferred designs:

The traction device of the present invention is a double-drum hoist with a hydraulic jack, wherein one drum is driven by its own electric motor to pull a pulley to lift the bucket screen, and the other drum is driven by the hydraulic jack to control the connection. The tension of the prestressed cable of the movable pulley.

The buffer pad of the present invention is a buffer pad with a built-in spring, and the buffer pad needs to have sufficient rigidity and height to prolong the unloading process of the bucket screen, so as to tension the prestressed cable for the hydraulic jack and add an equivalent bucket to the moving pulley synchronously. Sufficient operation time is reserved for the pulling force of the screen unloading to avoid the sudden change of the hanging load on the lifting point due to the instant unloading of the bucket screen directly touching the ground.

In the pulley block of the present invention, the hook on the upper end of each movable pulley is connected to a traction rope, and the traction rope bypasses the corresponding fixed pulley and the movable pulley in turn and then connects to the traction device.

The present invention has the following beneficial effects:

(1) The present invention provides a detachable reset design method for a bucket screen for a large-span flexible tension cable dome structure system. During the disassembly and reset process of the device, the tension in the prestressed cable can be controlled to ensure that the cable members of the cable dome structure are less affected by the force and ensure the safety of the cable dome structure building.

(2) The present invention is provided with a specific pulley block, which is easy to manufacture and install, and can simultaneously realize the lifting and lowering of the bucket screen and the pre-stressed steel cable, which helps to ensure that the hanging load at the same hanging point is unchanged, thereby reducing the number of cables. The force of the components ensures that the disassembly and reset process of the bucket screen is safe and reliable.

(3) The disassembly and reset process of the bucket screen device mainly relies on traction equipment such as hoists, and does not need to rely on too much manpower for high-altitude operations, which not only improves the construction efficiency, but also improves the construction safety. Promotion and use in engineering.

(4) The method of the present invention can not only be applied to the installation design of the bucket screen in the large-span flexible tension cable dome structure system, but also can provide a reference for the installation design of the bucket screen in other large-span roof structure systems.

Description of drawings

1 is a three-dimensional model of a cable dome structure in an embodiment;

Fig. 2 is the structure diagram of a kind of hanging bucket screen in the embodiment;

Fig. 3 is the device connection schematic diagram of the disassembly and reset process of the bucket screen in the embodiment;

4 is a schematic diagram of the disassembly process of the bucket screen device in the embodiment;

5 is a schematic diagram of the reset process of the bucket screen device in the embodiment;

Fig. 6 is the front view of the pulley block in the embodiment;

Figure 7 is a side view of the pulley block in Figure 5;

Fig. 8 is the schematic diagram of the combined equipment of the double drum hoist with hydraulic jack;

Description of reference numerals

Fixed pulley - a1, a2; moving pulley - b1, b2;

1- bucket screen; 2-prestressed cable; 3-ground anchor; 4-anchor cable joint; 5-diffusion plate; 6-buffer pad; 7-traction device; 7a-first traction rope; 7b-second traction rope; 7c-movable splint; 7d-second traction rope fixed joint; 7e-jack; 8-pad.

Detailed ways

The technical solutions of the present invention are described in detail below with reference to the accompanying drawings and embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention.

As shown in Figure 1, the cable dome structure of a gymnasium is shown. The bucket screen shown in Figure 2 is hung in the center of the gymnasium. The bucket screen weighs 50 tons. The vertical load of the hanging point is 6.25 tons. Follow the steps below to dismantle and reset the bucket screen:

As shown in Figure 3 to Figure 8

Disassembly step (1): see Figure 3, install a pulley block at each bucket screen hanging point of the cable dome structure, a total of 8 pulley blocks, the composition of each pulley block is shown in Figures 6 and 7, including two fixed on the The integral fixed pulley and two movable pulleys are the fixed pulley a1, the movable pulley b1, the fixed pulley a2, and the movable pulley b2. The fixed pulley a1 and the fixed pulley a2 are connected together on a hanging point, and the movable pulley b1 is connected below the fixed pulley a1. , the movable pulley b2 is connected under the fixed pulley a2, and a prestressed cable 2 is set up, so that one end of the prestressed cable 2 is fixedly connected to the ground anchor 3 embedded in the site below the bucket screen 1. In this embodiment, the prestressed The cable 2 is connected to the ground anchor 3 through the anchor cable joint 4, and the other end of the prestressed cable 3 is dispersed into 8 cables through the diffusion plate 5, which are respectively connected to the hooks at the lower end of the movable pulley b1 in each pulley block. The hook at the lower end of the other movable pulley b2 corresponds to the suspension point connecting the bucket screen 1, and the hook at the upper end of each movable pulley of each pulley block is connected to a traction rope, and the traction rope bypasses the corresponding fixed pulley and the movable pulley in turn. Connect the traction device 7, that is, the movable pulley b1 and the movable pulley b2 are respectively connected with the traction device 7;

Dismantling step (2): see Fig. 4, pre-place a buffer pad 6 on the field below the bucket screen 1, and lower each movable pulley b2 connected to the bucket screen 1 through the traction device 7, so that the bucket screen 1 is lowered, and the bucket screen 1 touches the When the surface of the buffer pad 6 is in a critical state that has not been unloaded, the movable pulley b2 connected with the bucket screen 1 gradually removes the weight of the bucket screen 1 attached to the movable pulley b2, and transfers the weight of the bucket screen 1 to the buffer pad 6. At the same time, through the traction device 7. Tighten the other movable pulley b1 connected with the prestressed cable 2 in the pulley block, and control the pulling force of the traction device 7 so that the pulling force applied to the prestressed cable 2 is equal to the weight of the bucket screen transferred to the buffer pad 6;

In the whole process of removing the bucket screen 1, a force control method is adopted through the same control system, that is, the unloading amount of the bucket screen 1 per unit time is controlled to be consistent with the increase of the tension force of the prestressed cable 2 per unit time, and the unloading amount of the bucket screen 1 is the same. It can be converted according to the subsidence displacement of the surface of the buffer pad, which can ensure that the weight of the removed vertical bucket screen and the applied vertical prestressed cable 2 are synchronously consistent. Since the incidental load of each pulley block is borne by the corresponding hanging point, it can ensure that the load of each hanging point remains unchanged.

Disassembly step (3): After the bucket screen 1 is completely removed, the hooks of the eight movable pulleys b2 connected with the bucket screen 1 are separated from the suspension points of the bucket screen 1, and the movable pulley b1 connected with the prestressed cable 2 is separated. Keep it still, load the prestressed cable 2 with a load equivalent to the weight of the bucket screen 1, that is, the vertical tension loaded by the prestressed cable 2 is 50 tons, and finally retract the bucket screen 1 and the buffer pad 6;

After the bucket screen is repaired and assembled, the reset and installation process of the bucket screen is shown in Figure 5, including the following steps:

Reset step (1): lower the movable pulley b2 that is vacant in the pulley block and used to connect with the bucket screen 1, and connect each suspension point of the bucket screen 1 to the hooks of the lower moving pulleys b2;

Resetting step (2): Gradually tighten the 8 movable pulleys connected to the bucket screen 1 through the traction device 7, and the 8 movable pulleys gradually add part of the weight lifted by the bucket screen, and the additional vertical weights of the last 8 movable pulleys are At the same time, the movable pulley b1 connected to the prestressed cable 2 in the pulley block is lowered through the traction device 8, so that the pulling force of the prestressed cable 2 is equal to the weight added to each movable pulley b2 during the lifting of the bucket screen 1. and;

Reset step (3): After the bucket screen 1 is completely hoisted, the eight movable pulleys b2 connected to the bucket screen 1 are gradually raised to the specified height, and then the hanging point of the bucket screen 1 is connected to the hanging point of the cable dome structure. After the other 8 movable pulleys b1 connected with the prestressed cable 2 are gradually lowered to the ground, the prestressed cable 2 is removed.

As a preferred embodiment:

As shown in FIGS. 3 to 5 , a backing plate 8 is arranged on the cable dome structure, and a plurality of traction devices 7 corresponding to the number of pulley blocks are arranged on the backing plate 8. The traction device 7 is a double drum hoist with a hydraulic jack , see Figure 8, one of the reels is driven by its own motor, which is provided with a first traction rope 7a, the first traction rope 7a pulls the pulley b2 to lift the bucket screen 1, and the other drum is provided with a second traction rope 7b, the second traction rope 7b is clamped by the second traction rope fixing joint 7d on the movable splint 7c, and the movable splint 7c rides on the action head of the hydraulic jack 7e, and can drive the second traction rope 7b through the expansion and contraction of the action head. When retracting, the hydraulic jack 7e drives and controls the tension of the prestressed cable 2 connected to the movable pulley b1. The hydraulic jack 7e can precisely control the tension of the prestressed cable 2.

The buffer pad 6 is a buffer pad with a built-in spring, and the buffer pad 6 needs to have sufficient rigidity and height to prolong the unloading process of the bucket screen 1, so that the unloading amount of the bucket screen can be obtained by conversion according to the subsidence displacement of the surface of the buffer pad 6, so as to be Hydraulic jack 7e tensioning prestressed cable 2 reserves enough operation time for the process of synchronizing the moving pulley with the pulling force equivalent to unloading the bucket screen, so as to avoid the instant unloading of the bucket screen directly touching the ground and causing the hanging load on the lifting point Dramatic changes.

As shown in FIGS. 6 and 7 , in the pulley block, the hook at the upper end of the movable pulley is connected to the traction rope, and the traction rope bypasses the fixed pulley and the movable pulley in turn and then connects to the traction device 7 .

The above-mentioned embodiments are only preferred embodiments of the present invention, but are not intended to limit the invention. Any modifications and improvements made on the basis of the concept of the present invention should fall within the protection scope of the present invention. The specific protection scope is as follows: The claims record shall prevail.

Claims (5)

1. The detachable reset design method applied to the scoop screen in the large-span cable dome structure is characterized in that: the bucket screen disassembling process comprises the following steps,

disassembling step (1): a group of pulley blocks are installed at each bucket screen hanging point of a cable dome structure, each pulley block comprises two fixed pulleys and two movable pulleys which are fixed into a whole, the fixed pulleys are connected to the hanging points, the two movable pulleys are connected below the corresponding fixed pulleys, a prestressed guy cable is arranged, one end of the prestressed guy cable is fixedly connected to a ground anchor embedded in a field below the bucket screen, the other end of the prestressed guy cable is dispersed into a plurality of guy cables through a diffusion disc, the dispersed guy cables are respectively and correspondingly connected with a hook at the lower end of one movable pulley in each pulley block, a hook at the lower end of the other movable pulley of each pulley block is correspondingly connected with a hanging point of the bucket screen, and the movable pulleys of each pulley block are respectively connected with a traction device;

disassembling step (2): placing a cushion pad in advance on the field below the hopper screen, lowering each movable pulley connected with the hopper screen through the traction device to enable the hopper screen to descend, gradually unloading the weight of the hopper screen attached to the movable pulley by the movable pulley connected with the hopper screen from the critical state that the hopper screen is in contact with the surface of the cushion pad and is not unloaded, transferring the weight of the hopper screen to the cushion pad, and simultaneously tightening the other movable pulley connected with a prestress cable in the pulley block through the traction device to control the tension of the traction device so that the tension applied to the prestress cable is equal to the weight of the hopper screen transferred to the cushion pad;

disassembling step (3): after the hopper screen is completely removed, a lifting hook of a movable pulley connected with the hopper screen is separated from a suspension point of the hopper screen, and the movable pulley connected with a prestressed inhaul cable is kept still, so that the prestressed inhaul cable loads a load equivalent to the weight of the hopper screen;

the reset installation process of the bucket screen comprises the following steps,

resetting step (1): lowering a movable pulley which is arranged in the pulley block in a hollow way and is used for being connected with the hopper screen, and correspondingly connecting each suspension point of the hopper screen with a lower end lifting hook of each lowered movable pulley;

resetting step (2): the movable pulleys connected with the hopper screen are gradually tightened through the traction device, the movable pulleys are gradually added with part of the weight lifted by the hopper screen, and meanwhile, the movable pulleys connected with the prestressed stay cables in the pulley block are placed downwards through the traction device, so that the pulling force removed by the prestressed stay cables is equal to the sum of the weights of the movable pulleys added in the process of lifting the hopper screen;

resetting step (3): after the bucket screen is completely lifted, the movable pulley connected with the bucket screen gradually rises to a specified height, then the suspension point of the bucket screen is connected with the suspension point of the cable dome structure, the movable pulley connected with the prestressed inhaul cable is gradually lowered to the ground, and then the prestressed inhaul cable is detached.

2. The detachable reset design method of the scoop screen applied to the large-span cable dome structure according to claim 1, wherein: each pulley block is connected with a traction device, the traction device is a double-drum winch with a hydraulic jack, one drum is driven by a self-contained motor to pull a movable pulley to enable the bucket screen to lift, and the other drum is driven by the hydraulic jack to control the tension of the prestress stay cable connected with the movable pulley.

3. The detachable reset design method of the scoop screen applied to the large-span cable dome structure according to claim 2, characterized in that: and a base plate is arranged on the cable dome structure, and a plurality of traction devices corresponding to the pulley block in number are arranged on the base plate.

4. The detachable reset design method of the scoop screen applied to the large-span cable dome structure according to claim 1, wherein: the buffer pad is a buffer pad with a built-in spring.

5. The detachable reset design method of the scoop screen applied to the large-span cable dome structure according to any one of claims 1 to 4, characterized in that: in the pulley block, a hook at the upper end of each movable pulley is connected with a traction rope, and the traction rope sequentially bypasses the corresponding fixed pulleys and the movable pulleys and then is connected with the traction device.

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