CN115072544B - Hoisting method for hoisting steel net rack - Google Patents

Abstract

The invention discloses a hoisting method for hoisting a steel mesh frame, which comprises the steps of obtaining the maximum distance between adjacent stress points on a steel mesh frame model on the basis of maximum deformation value, maximum bending stress and maximum torque allowed by the steel mesh frame; then according to the size of the steel net frame and the number of stress points, the hanging beam is assembled, then the position of the hanging hook on the box model is moved, so that the hanging hook is connected with the corresponding stress point of the steel net frame, according to the position of the gravity line of the steel net frame, the crane hook is placed on the gravity line of the steel net frame, then the hanging ring corresponding to each stress point is connected with the crane hook through the rigid ropes, the prestress among the rigid ropes 2 is kept consistent, the deformation characteristics of the steel net frame structure can be accurately known through numerical simulation, the maximum distance between the hanging beam hanging hooks and the minimum number of the hanging hooks are reversely designed through comparing the deformation value of the model with the allowable deformation value, the construction cost is saved while the stability of the steel net frame lifting is ensured, and in addition, the hanging beam device is convenient to install and detach.

Description

A lifting method for lifting steel grid

Technical Field

The invention relates to the technical field of steel grid hoisting, and in particular to a hoisting method for hoisting a steel grid.

Background Art

At present, with the continuous development of large-span steel structures, the size of steel grid structures is increasing. Due to the advantages of light weight, high rigidity and good seismic performance, steel structures are widely used in the roofs of public buildings such as gymnasiums, shopping malls, and waiting halls. In actual projects, a single crane is generally used for lifting and installation. Due to the small number of lifting fulcrums, the steel grid is prone to local buckling, causing damage to the steel grid. In order to prevent such situations from happening, multiple cranes are usually used for collaborative lifting operations, but there are problems such as poor coordination and low work efficiency during the lifting process, which also causes a waste of crane mechanical resources.

Summary of the invention

The purpose of the present invention is to provide a lifting method for lifting a steel grid frame to overcome the shortcomings of the prior art.

To achieve the above object, the present invention provides the following technical solution: a lifting method for lifting a steel grid, comprising the following steps:

Step 1: Select the stress points and the center of gravity of the steel grid; construct a steel grid model consistent with the actual situation through finite element numerical simulation software, obtain the maximum distance between adjacent stress points on the steel grid model based on the maximum allowable deformation value, maximum bending stress and maximum torque of the steel grid, and determine the center of gravity of the steel grid, where the stress points should be distributed around the center of gravity of the steel grid so that the steel grid can maintain a stable shape after being subjected to vertical force;

Step 2, assembling the hanging beam; assembling the hanging beam according to the size of the steel grid and the number of stress points, the hanging beam is composed of at least two box models spliced together, and the adjacent box models are connected by high-strength bolts so that the adjacent box models are in surface contact and form a whole; a lifting ring is set at the center of the top of each box model, and two sets of steel ropes are set on the hanging beam structure through the lifting ring; a hook is set at the center of the bottom of each box model, and the hook is connected to the corresponding steel grid;

Step three, connect the hanging beam to the steel grid; move the hook position on the box model so that the hook is connected to the corresponding stress point of the steel grid, ensuring that the hook and the corresponding stress point are on the same vertical plane so that there is only vertical force between the hanging beam and the steel grid.

Step 4, install the crane hook and connect it to the hanging beam; according to the centerline position of the steel grid in step 1, place the crane hook on the centerline position of the steel grid, and then connect the lifting ring corresponding to each stress point to the crane hook through a steel rope, and the prestress between the steel ropes remains consistent.

As a further solution of the present invention: the suspension beam structure is composed of at least two box models spliced together, and adjacent box models are connected by high-strength bolts so that adjacent box models are in surface contact and form a whole.

As a further solution of the present invention: a lifting ring is provided at the center of the top of each box model, and the steel rope is looped on the hanging beam structure through the lifting ring; a lifting hook is provided at the center of the bottom of each box model;

As a further solution of the present invention: the force points of the lifting ring and the lifting hook on the same box model are located on the same vertical line.

As a further solution of the present invention, it is characterized in that the number of the steel wire ropes is at least two.

As a further solution of the present invention: the box model is hollow inside; through grooves are provided at corresponding positions of the upper panel and the lower panel of the box model, and limiting and reinforcing plates are fixedly provided inside the box model on both sides of the through grooves;

As a further solution of the present invention: a hook base is provided at the end of the hook, and a ring base is provided at the end of the ring; the hook passes through the through slot of the lower panel of the box model, and the hook base is located inside the box model and is clamped with the limit and reinforcement plates at the corresponding positions; the ring passes through the through slot of the upper panel of the box model, and the ring base is located inside the box model and is clamped with the limit and reinforcement plates at the corresponding positions, and a support plate is provided in the box model below the ring base for supporting the ring and the ring base; the ring base and the hook base are connected as a whole by a retractable rod, so that the hook and the electric ring can move along the through slot direction and ensure that the force points of the ring and the hook on the same box model are located on the same vertical line.

As a further solution of the present invention: the working surfaces of the lifting ring base and the lifting hook base are both corrugated surface structures, and the working surfaces of the limiting and reinforcing plates are both corrugated surface structures, so that the lifting ring base and the lifting hook base will not have relative displacement after being pressed against the corresponding limiting and reinforcing plates.

As a further solution of the present invention: a moving mechanism is symmetrically arranged on both sides of the hook base, and the moving mechanism includes rollers. The rollers are in contact with the inner surface of the lower panel of the box model and roll thereon. A guide shaft is arranged above the rollers, and the guide shaft is connected to the roller shaft of the roller through a bushing, and the guide shaft is movably connected to the hook base.

According to a further embodiment of the present invention: through holes are symmetrically arranged on the hook base, and the guide shaft can freely pass through the through holes at corresponding positions on the hook base, so that the guide shaft can freely move up and down along the through holes; a preload spring is sleeved on the guide shaft and is stuck in the space between the lower surface of the hook base and the shaft sleeve; the rebound displacement of the preload spring is greater than the height difference between the limit and reinforcement plate and the shaft sleeve; so that when there is no vertical external force, the hook and the lifting ring can be driven by the moving mechanism to move along the through groove direction, so that the position adjustment of the hook and the lifting ring can be achieved.

The design principle of the present invention, the technical differences and effects compared with the prior art:

1. The present invention firstly simulates the steel grid model respectively through finite element numerical simulation software, obtains the maximum distance between adjacent stress points on the steel grid model based on the maximum allowable deformation value, maximum bending stress and maximum torque, and determines the center of gravity position and center of gravity line of the steel grid; then, the box model and the steel rope model are respectively simulated through finite element numerical simulation to obtain the material and wall thickness of the box model; and the material of the steel rope, so that the strength and deformation of the box model and the steel rope meet the relevant requirements.

2. According to the maximum distance of the stress points on the steel grid model and the position of the center of gravity of the steel grid; with the center of gravity of the steel grid as the center, select the corresponding steel grid structure points on the steel grid around it as stress points; then adjust the position of the hook on the hanging beam formed by the box model so that the hook is connected to the corresponding stress point of the steel grid. The distance is adjusted so that there is only vertical tension between each hook and the corresponding stress point of the steel grid.

3. Since the lifting ring and the hook in this application are located on the same vertical line, and the lifting ring is connected to the crane hook through an inclined steel rope, wherein the crane hook is located on the center of gravity of the steel grid, the hook gives it a numerical downward pulling force, and the steel rope gives it an oblique pulling force; then for the box model, the oblique pulling force of the steel rope can be decomposed into the vertical pulling force in the Z-axis, the horizontal pulling force in the X-axis direction, and the horizontal pulling force in the Z-axis direction; since the lifting ring and the hook are located on the same vertical line, the pulling force in the Z-axis direction offsets the downward pulling force of the hook, and the horizontal force in the X-axis direction can be offset by high-strength bolts or the compressive strength of the box model itself, and the horizontal force in the Y-axis direction generates torque for a single box model, which can be offset by the single box model itself and the high-strength bolts; since the center of gravity of the crane hook coincides with the steel grid and the hook is subjected to vertical forces, the horizontal force in the Y-axis direction as a whole generates a balanced torque for the suspension beam composed of the box model.

Compared with the prior art, the present invention has the following beneficial effects:

1. The present invention can accurately know the deformation characteristics of the steel grid structure through numerical simulation. By comparing the model deformation value with the allowable deformation value, the maximum spacing of the lifting beam hooks and the minimum number of hooks are reversely designed to ensure the stability of the steel grid lifting while saving costs.

2. The design method of the present invention can be applied to the design of lifting beams of steel grid structures of different types and sizes.

3. The lifting beam device of the present invention can be installed at the hook of a single crane, so that a single crane equipment can lift the steel grid structure, saving crane resources and reducing construction costs.

4. The lifting beam device of the present invention is assembled from box-type modules. The box-type section has good bending and torsional resistance and high stability. In addition, the lifting beam device is easy to install and disassemble, and the construction is convenient.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

FIG1 is a diagram of a lifting beam device of the present invention;

FIG2 is a flow chart of a method for designing a lifting beam according to the present invention;

FIG3 is a side view of FIG1 ;

FIG4 is a top view of a single box model in the present invention;

Fig. 5 is a cross-sectional view taken along line A-A of Fig. 4;

Fig. 6 is a cross-sectional view taken along line B-B of Fig. 5;

FIG7 is a schematic diagram of the structure of the mobile mechanism of the present invention;

FIG8 is a schematic diagram showing the forces acting on various structures in the present invention.

In the figure: 1 box-type module, 1.1 through slot, 1.2 limit and reinforcement plate, 1.3 support plate, 1.4 telescopic rod, 2 steel rope, 3 hook, 3.1 hook base, 3.11 roller, 3.12 guide shaft, 3.13 bushing, 3.14 preload spring, 3.15 roller shaft, 4 ring, 4.1 lifting ring base, 5 high-strength bolts, 6 steel grid structure, 7 crane hook, 8 steel grid center of gravity line.

DETAILED DESCRIPTION

The embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

Referring to Figures 1-7, the present invention provides a lifting beam device for lifting a steel grid, including a single crane hook 7, and also including a hanging beam structure composed of a box model 1, wherein the hanging beam structure is composed of at least two box models 1 spliced together, and adjacent box models 1 are connected by high-strength bolts 5, so that adjacent box models 1 achieve surface contact and form a whole, and a lifting ring 4 is arranged at the center of the top of each box model 1, and a steel rope 2 is sleeved on the hanging beam structure through the lifting ring 4; a hook 3 is arranged at the center of the bottom of each box model 1, and the force points of the lifting ring 4 and the hook 3 on the same box model 1 are located on the same vertical line; the hanging beam structure is connected to the single crane hook 7 by a steel rope 2, and the number of the steel wire ropes 2 is at least two, and a hook 3 is arranged at the lower part of the hanging beam structure and is connected to the steel grid structure 6 through the hook 3.

The box model 1 is hollow inside; through slots 1.1 are provided at corresponding positions of the upper panel and the lower panel of the box model 1, and limit and reinforcement plates 1.2 are fixedly provided inside the box model 1 on both sides of the through slots 1.1; a hook base 3.1 is provided at the end of the hook 3, and a ring base 4.1 is provided at the end of the ring 4; the hook 3 passes through the through slot 1.1 of the lower panel of the box model 1, and the hook base 3.1 is located inside the box model 1 and is clamped with the limit and reinforcement plates 1.2 at corresponding positions; the ring 4.1 passes through the through slot 1.1 of the upper panel of the box model 1, and the ring base 4.1 passes through the through slot 1.1 of the upper panel of the box model 1, and the ring base 4.1 passes through the through slot 1.1 of the upper panel of the box model 1. 1 is located inside the box model 1 and is clamped with the limit and reinforcement plate 1.2 at the corresponding position. A support plate 1.3 is provided in the box model 1 below the ring base 4.1 to support the ring 4 and the ring base 4.1; the ring base 4.1 and the hook base 3.1 are connected as a whole through a telescopic rod 1.4, so that the hook 3 and the electric ring 4 can move along the through groove 1.1 and ensure that the force points of the ring 4 and the hook 3 on the same box model 1 are located on the same vertical line; the working surfaces of the ring base 4.1 and the hook base 3.1 are both corrugated surface structures, and the working surfaces of the limit and reinforcement plate 1.2 are All of them are corrugated surface structures, so that the ring base 4.1 and the hook base 3.1 will not be relatively displaced after being pressed against the corresponding limit and reinforcement plates 1.2; moving mechanisms are symmetrically arranged on both sides of the hook base 3.1, and the moving mechanisms include rollers 3.11, which are in contact with the inner surface of the lower panel of the box model 1 and roll thereon, and a guide shaft 3.12 is arranged above the roller 3.11, and the guide shaft 3.12 is connected to the roller shaft 3.15 of the roller 3.11 through a shaft sleeve 3.13, and the guide shaft 3.12 is movably connected to the hook base 3.1; symmetrically arranged on the hook base 3.1 A through hole is provided, and the guide shaft 3.12 can freely pass through the through hole at the corresponding position on the hook base 3.1, so that the guide shaft 3.12 can move freely up and down along the through hole; a preload spring 3.14 is sleeved on the guide shaft 3.12 and the preload spring 3.14 is stuck in the space between the lower surface of the hook base 3.1 and the shaft sleeve 3.13; the rebound displacement of the preload spring 3.14 is greater than the height difference between the limit and reinforcement plate 1.2 and the shaft sleeve 3.13; so that when there is no vertical external force, the hook 3 and the lifting ring 4 can be driven by the moving mechanism to move along the direction of the through groove 1.1 to achieve the position adjustment of the hook 3 and the lifting ring 4.

The design method of the lifting beam device of this embodiment, wherein the design method of the spacing and number of hooks comprises the following steps:

S1, construct a steel grid model consistent with the actual situation in the finite element numerical simulation software ABAQUS;

S2, giving the steel grid model material parameters consistent with the actual project;

S3, two hooks are set at any nodes on the upper part of the steel grid model;

S4, set the constraints of the hook in the x, y, and z directions;

S5, applying gravity load to the steel grid model;

S6, obtaining the mid-span deformation value of the steel grid model between the two hooks according to the displacement cloud map, and comparing it with the mid-span allowable deformation value;

S7, adjusting the distance between the two hooks on the upper part of the steel grid model, and then comparing the mid-span deformation value of the steel grid model obtained according to the displacement cloud map with the mid-span allowable deformation value, until the mid-span deformation value of the steel grid model between the two hooks is less than the mid-span allowable deformation value, and determining the maximum distance between the hooks;

S8, arranging the hooks at equal intervals according to the maximum interval determined in step S7, obtaining the deformation value of the cantilever of the steel grid model according to the displacement cloud map, and comparing it with the allowable cantilever sinking value;

S9, adjusting the position of the upper hook of the steel grid model, and then using the displacement cloud map to obtain the deformation value of the cantilever of the steel grid model and compare it with the allowable cantilever sinking value, until the deformation value of the cantilever of the steel grid model is less than the allowable cantilever sinking value, and determining the minimum number of hooks;

The design method of the lifting beam device of this embodiment, wherein the design method of the box model comprises the following steps:

S1, a box model with a certain wall thickness is established in the finite element numerical simulation software ABAQUS, a bolt model is established using shell elements, and a lifting beam model is formed by assembling several box models and several bolt models;

S2, giving the box model and bolt model material parameters equivalent to those of steel;

S3, arranging hooks at the lower part of the box model according to the hook spacing;

S4, a concentrated load equivalent to the deadweight of the steel grid is applied at the hook;

S5, obtaining the maximum tensile stress and deformation of the box model according to the stress nephogram and the displacement nephogram, and comparing them with the maximum allowable tensile stress and the allowable deformation respectively;

S6, adjusting the material parameters of the box model in step S2, and then obtaining the maximum tensile stress and deformation of the box model according to the stress cloud map and the displacement cloud map, and comparing them with the maximum allowable tensile stress and the allowable deformation respectively, until the maximum tensile stress of the box model is less than the maximum allowable tensile stress and the deformation is less than the allowable deformation, and determining the material parameters and wall thickness of the box model.

The design method of the lifting beam device of this embodiment, wherein the design method of the steel rope comprises the following steps:

S1, establish a steel rope model with the same length and diameter as that in the actual project in the finite element numerical simulation software ABAQUS;

S2, giving the steel rope model material parameters equivalent to those of steel;

S3, one end of the steel rope model is set to be bound and connected to the circular ring on the upper part of the box-type module model, and the other end is fixed with constraints in the x, y, and z directions;

S4, a concentrated load equivalent to the sum of the deadweight load of the steel grid and the deadweight load of the box-type module is applied to the box-type module;

S5, obtaining the elongation of the steel rope model according to the displacement cloud diagram, and comparing it with the allowable elongation;

S6, adjusting the material parameters of the steel rope model, and then obtaining the elongation of the steel rope model according to the displacement cloud map and comparing it with the allowable elongation, until the elongation of the steel rope model is less than the allowable elongation, and determining the material parameters of the steel rope.

The lifting method of this embodiment comprises the following steps:

Step 1, select the stress points and the center of gravity of the steel grid; construct a steel grid model consistent with the actual situation through finite element numerical simulation software, obtain the maximum distance between adjacent stress points on the steel grid model based on the maximum allowable deformation value, maximum bending stress and maximum torque of the steel grid, and determine the center of gravity of the steel grid 8, wherein the stress points should be distributed around the center of gravity of the steel grid so that the stress points can maintain a stable shape after being subjected to vertical force;

Step 2, assembling the hanging beam; assembling the hanging beam according to the size of the steel grid and the number of stress points, the hanging beam is composed of at least two box models 1 spliced together, and the adjacent box models 1 are connected by high-strength bolts 5, so that the adjacent box models 1 are in surface contact and form a whole; a lifting ring 4 is set at the center of the top of each box model 1, and the steel rope 2 is set on the hanging beam structure through the lifting ring 4; a hook 3 is set at the center of the bottom of each box model 1; the stress points of the lifting ring 4 and the hook 3 on the same box model 1 are located on the same vertical line;

Step three, connect the hanging beam to the steel grid; move the position of the hook 3 on the box model 1 so that the hook 3 is connected to the corresponding force point of the steel grid, ensuring that the hook 3 and the corresponding force point are on the same vertical plane, so that there is only vertical force between the hanging beam and the steel grid.

Step 4, install the crane hook and connect it to the hanging beam; according to the position of the center of gravity of the steel grid in step 1, place the crane hook 7 on the center of gravity 8 of the steel grid, and then connect the lifting ring 4 corresponding to each stress point to the crane hook 7 through the steel rope 2, and the prestress between the steel ropes 2 remains consistent.

Finally, it should be noted that when describing the position of each component and the matching relationship between them, the present invention usually takes one/a pair of components as an example. However, those skilled in the art should understand that such position, matching relationship, etc. are also applicable to other components/other pairs of components.

The above description is merely an exemplary embodiment of the present invention and is not intended to limit the protection scope of the present invention. The protection scope of the present invention is determined by the appended claims.

Claims (8)

1. A lifting method for lifting a steel grid, characterized by comprising the following steps: Step 1: Select the stress points and the center of gravity of the steel grid; construct a steel grid model consistent with the actual situation through finite element numerical simulation software, obtain the maximum distance between adjacent stress points on the steel grid model based on the maximum allowable deformation value, maximum bending stress and maximum torque of the steel grid, and determine the center of gravity of the steel grid, where the stress points should be distributed around the center of gravity of the steel grid so that the steel grid can maintain a stable shape after being subjected to vertical force; Step 2, assembling the hanging beam; assembling the hanging beam according to the size of the steel grid and the number of stress points, the hanging beam is composed of at least two box models spliced together, and the adjacent box models are connected by high-strength bolts so that the adjacent box models are in surface contact and form a whole; a lifting ring is set at the center of the top of each box model, and the steel rope is set on the hanging beam structure through the lifting ring; a hook is set at the center of the bottom of each box model, and the hook is connected to the corresponding steel grid; Step 3: Connect the hanging beam to the steel grid; move the hook position on the box model so that the hook is connected to the corresponding force point of the steel grid, and ensure that the hook and the corresponding force point are on the same vertical plane so that there is only vertical force between the hanging beam and the steel grid; Step 4, install the crane hook and connect it to the hanging beam; according to the centerline position of the steel grid in step 1, place the crane hook on the centerline position of the steel grid, and then connect the lifting ring corresponding to each stress point to the crane hook through a steel rope, and keep the prestress between the steel ropes consistent. 2. A lifting method for lifting a steel grid according to claim 1, characterized in that: the lifting beam structure is composed of at least two box models spliced together, and adjacent box models are connected by high-strength bolts so that adjacent box models achieve surface contact and form a whole. 3. A lifting method for lifting a steel grid according to claim 2, characterized in that: a lifting ring is provided at the center of the top of each box model, and the steel rope is looped on the hanging beam structure through the lifting ring; a lifting hook is provided at the center of the bottom of each box model; The force bearing points of the lifting ring and the lifting hook on the same box model are located on the same vertical line. 4. A lifting method for lifting a steel grid according to claim 1, characterized in that the number of the steel ropes is at least two. 5. A lifting method for lifting a steel grid according to claim 2, characterized in that: the interior of the box model is hollow; through grooves are provided at corresponding positions of the upper panel and the lower panel of the box model, and limit and reinforcement plates are fixedly provided on the inner side of the box model on both sides of the through grooves; A hook base is provided at the end of the hook, and a ring base is provided at the end of the ring; the hook passes through the through slot of the lower panel of the box model, and the hook base is located inside the box model and clamped with the limit and reinforcement plates at the corresponding positions; the ring passes through the through slot of the upper panel of the box model, and the ring base is located inside the box model and clamped with the limit and reinforcement plates at the corresponding positions, and a support plate is provided in the box model below the ring base for supporting the ring and the ring base; the ring base and the hook base are connected as a whole by a retractable rod, so that the hook and the electric ring can move along the through slot direction and ensure that the force points of the ring and the hook on the same box model are located on the same vertical line. 6. A lifting method for lifting a steel grid according to claim 5, characterized in that the working surfaces of the lifting ring base and the hook base are both corrugated surface structures, and the working surfaces of the limit and reinforcement plates are both corrugated surface structures, so that the lifting ring base and the hook base will not have relative displacement after being tightened against the corresponding limit and reinforcement plates. 7. A lifting method for lifting a steel grid according to claim 5, characterized in that: a moving mechanism is symmetrically arranged on both sides of the hook base, the moving mechanism includes rollers, the rollers are in contact with the inner surface of the lower panel of the box model and roll thereon, a guide shaft is arranged above the rollers, the guide shaft is connected to the roller shaft of the roller through a bushing, and the guide shaft is movably connected to the hook base. 8. A lifting method for lifting a steel mesh frame according to claim 7 is characterized in that: through holes are symmetrically arranged on the hook base, and the guide shaft freely passes through the through holes at corresponding positions on the hook base, so that the guide shaft can move freely up and down along the through holes; a pre-tightening spring is sleeved on the guide shaft and the pre-tightening spring is stuck in the space between the lower surface of the hook base and the sleeve; the rebound displacement of the pre-tightening spring is greater than the height difference between the limit and reinforcement plate and the sleeve; so that when there is no vertical external force, the hook and the lifting ring can be driven by the moving mechanism to move along the through groove direction to realize the position adjustment of the hook and the lifting ring.