A lower hanging point lifting device and a lower hanging point integrated overall lifting method

Abstract

The present invention provides a lower hanging point lifting device and an integrated lower hanging point lifting method, which relate to the field of steel structure engineering. The lifting device is symmetrically distributed around the circumference of the truss. The lower hanging point lifting device includes a lifting bracket, a hydraulic lifter, a steel strand, a hanging plate and two groups of connecting rods. The present invention simplifies the hanging point form, eliminates three temporary rods, reduces the amount of measures for the temporary structure, and greatly reduces a large amount of high-altitude disassembly work after lifting into place, saving construction time; the truss is lifted as a whole to the designed elevation, and then the rods at the counterparts are welded and two groups of upper chords are welded, which will greatly reduce the on-site high-altitude construction volume and construction difficulty, and reduce construction costs.

Description

Technical Field

[0001] The invention relates to the field of steel structure engineering, and in particular to a lower hanging point lifting device and a lower hanging point integrated overall lifting method. Background Art

[0002] The truss structure is a beam-type component, which is a "hollow beam" composed of multiple small-section rods and is a statically determinate structure. Since its cross-section can be made very high, it has a large bending resistance and small deflection, which makes it suitable for larger spans than solid beams, and it saves materials and has a small deadweight. Truss structures are often used in public buildings such as large-span factories, exhibition halls, gymnasiums and bridges. Since they are mostly used in the roof structure of buildings, trusses are also commonly called roof trusses.

[0003] The main body of the truss is often welded on the ground, and then hoisted into place using lifting equipment. The traditional practice is that the temporary lifting point structure for conventional space structure lifting is in the form of three temporary rods intersecting as a lifting point (i.e., lifting point), and the lifting point is a perforated welded ball structure; the three temporary rods of this structure are removed after being lifted into place, and the perforated welded balls are non-standard parts and need to be specially customized.

[0004] The above construction method has the following shortcomings: first, it is difficult to construct and install; second, it is difficult to control deformation during the lifting process; third, the construction cost is high; fourth, the construction period is long. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a lower hanging point lifting device and an integrated lower hanging point lifting method, which greatly reduces a large amount of high-altitude disassembly work after lifting into place, saves construction time; and reduces the amount of high-altitude construction on site and the construction difficulty, thereby reducing construction costs.

[0006] The present invention is implemented through the following technical scheme: a lower hanging point lifting device, which is symmetrically distributed around the circumference of the truss, and the lower hanging point lifting device includes a lifting bracket, a hydraulic lifter, a steel strand, a hanging plate and two groups of connecting rods. The lifting bracket is fixed on the corbel at the top of the column, the hydraulic lifter is fixed on the lifting bracket, the hydraulic lifter pulls the steel strand upward, the hanging plate is fixedly connected to the lower end of the steel strand, the hanging plate is fixedly connected to the lower chord on the outside of the truss, the hanging plate and the hydraulic lifter overlap in the vertical direction, the two groups of connecting rods are located at the ends of the truss, one end of the connecting rod is fixedly connected to the middle part of the lower chord, and the other end of the connecting rod is fixedly connected to the first steel ball on the outside of the truss, and the connecting rod and the truss form a statically determinate structure.

[0007] The present invention simplifies the hanging point form, eliminates three temporary rods, reduces the amount of measures for temporary structures, and greatly reduces a large amount of high-altitude disassembly work after lifting into place, saving construction time; the truss is lifted as a whole to the designed elevation, and then the rods at the interface are welded and two sets of upper chords are welded, which will greatly reduce the amount of high-altitude construction on site and the construction difficulty, and reduce construction costs.

[0008] According to the above technical solution, preferably, the hanging plate includes a detachably connected plug plate and a hanger, the plug plate is vertically inserted into the lower chord on the outside of the truss, and the plug plate is fixedly connected to the lower chord, the hanger is fixedly connected to the lower end of the steel strand, the plug plate is permanently in the lower chord, and the hanger is detachably connected to the plug plate, thereby facilitating construction for workers while ensuring structural strength.

[0009] According to the above technical solution, preferably, during hoisting, the connecting rod is used as a temporary hoisting rod to effectively suppress the deformation of the truss during the lifting process; when hoisted into place, the connecting rod is used as a reinforcing rod to effectively enhance the overall strength of the outer side of the truss.

[0010] A method for lifting a lower suspension point in an integrated manner, using a lower suspension point lifting device, comprises the following steps:

[0011] Fix the lifting bracket on the bracket at the top of the column, and install the hydraulic lifter and steel strand in sequence;

[0012] Remove the two sets of upper chords on the outside of the truss, cut off the set length of the lower chord, weld two sets of connecting rods to vertically insert the plug plate into the lower chord at the end of the truss, and the plug plate is fixedly connected to the lower chord, the hanger is fixedly connected to the lower end of the steel strand, and the plug plate and the hanger are detachably connected;

[0013] The hydraulic lifters around the truss pull the steel strands upward, and the steel strands drive the truss to lift upward as a whole;

[0014] The truss is lifted to the set elevation, and two sets of upper chords, cut sections of lower chords and truss end balls are welded. At this time, the two ends of the upper chord are fixedly connected to the truss end balls and the first steel balls respectively. In the vertical direction, the upper end steel ball is facing the column, and the central axis of the cut section coincides with the central axis of the lower chord.

[0015] The beneficial effects of the present invention are as follows: the present invention simplifies the form of the hanging points, eliminates three temporary rods, reduces the amount of measures for the temporary structure, and greatly reduces a large amount of high-altitude disassembly work after lifting into place, thereby saving construction time; the truss is lifted as a whole to the designed elevation, and then the rods at the mating points are welded and two sets of upper chords are welded, which will greatly reduce the amount of high-altitude construction on site and the construction difficulty, and reduce construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1A schematic diagram of the structure during hoisting according to an embodiment of the present invention is shown.

[0017] Figure 2 A schematic diagram of the structure after hoisting according to an embodiment of the present invention is shown.

[0018] Figure 3 A schematic structural diagram of the connection between the hanging plate and the truss according to an embodiment of the present invention is shown.

[0019] Figure 4 A schematic structural diagram of a hanging plate according to an embodiment of the present invention is shown.

[0020] Figure 5 A top deformation diagram of a lifting bracket according to an embodiment of the present invention is shown.

[0021] Figure 6 A lifting bracket stress ratio diagram is shown according to an embodiment of the present invention.

[0022] Figure 7 A finite element analysis diagram according to an embodiment of the present invention is shown.

[0023] Figure 8 A distribution diagram of lifting points when a truss is lifted according to an embodiment of the present invention is shown.

[0024] In the figure: 1. lifting bracket; 2. hydraulic lifter; 3. steel strand; 4. hanging plate; 5. connecting rod; 6. plug plate; 7. lifting device; 8. lower chord; 9. truss; 10. first steel ball; 11. corbel; 12. column; 13. cutting section; 14. upper chord; 15. truss end ball. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and the best embodiments.

[0026] As shown in the figure, the present invention provides a lower hanging point lifting device, which is symmetrically distributed around the truss 9. The lower hanging point lifting device includes a lifting bracket 1, a hydraulic lifter 2, a steel strand 3, a hanging plate 4 and two groups of connecting rods 5, wherein the lifting bracket 1 is fixed to the bracket 11 at the top of the column 12, the hydraulic lifter 2 is fixed to the lifting bracket 1, the hydraulic lifter 2 pulls the steel strand 3 upward, and the hanging plate 4 includes a detachably connected plug plate 6 and a hanger 7, the plug plate 6 is vertically inserted into the lower chord 8 outside the truss 9, and the plug plate 6 is inserted into the lower chord 8 outside the truss 9. The plate 6 is fixedly connected to the lower chord 8, the hanger 7 is fixedly connected to the lower end of the steel strand 3, the plug plate 6 is permanently in the lower chord 8, and the hanger 7 is detachably connected to the plug plate 6, thereby facilitating the construction of the workers while ensuring the structural strength. The hanger 7 and the hydraulic lifter 2 overlap in the vertical direction, and the two sets of connecting rods 5 are located at the ends of the truss 9. One end of the connecting rod 5 is fixedly connected to the middle part of the lower chord 8, and the other end of the connecting rod 5 is fixedly connected to the first steel ball 10 on the outside of the truss 9. The connecting rod 5 and the truss 9 form a statically determinate structure.

[0027] Furthermore, when hoisting, the connecting rod 5 is used as a temporary hoisting rod, which can effectively suppress the deformation of the truss 9 during the lifting process; when hoisted into place, the connecting rod 5 is used as a reinforcing rod, thereby effectively enhancing the overall strength of the truss 9.

[0028] A method for lifting a lower suspension point in an integrated manner, using the above-mentioned lower suspension point lifting device, the working process includes the following steps:

[0029] (1) The lifting bracket 1 is fixedly mounted on the bracket 11 at the top of the column 12, and the hydraulic lifter 2 and the steel strand 3 are installed in sequence;

[0030] (2) Remove the two groups of upper chords 14 on the outside of the truss 9, and cut off a section 13 of a set length of the lower chord 8, preferably a length of 1.25 m from the center of the column 12, vertically insert the plug plate 6 into the lower chord 8 at the end of the truss 9, this position is about 1.7 m away from the center of the column 12, and the plug plate 6 is fixedly connected to the lower chord 8, weld two groups of connecting rods, and the hanger 7 is fixedly connected to the lower end of the steel strand 3, and the plug plate 6 and the hanger 7 are detachably connected;

[0031] (3) The hydraulic lifters 2 around the truss 9 pull the steel strands 3 upward, and the steel strands 3 drive the truss 9 to lift upward as a whole;

[0032] (4) The truss 9 is lifted to the set elevation, and two sets of upper chords 14, the cut section 13 of the lower chord 8, and the truss end ball 15 are welded. At this time, the two ends of the upper chord 14 are fixedly connected to the truss end ball 15 and the first steel ball 10 respectively. In the vertical direction, the end steel ball is opposite to the column 12, and the central axis of the cut section 13 coincides with the central axis of the lower chord 8.

[0033] The stress calculation process of the lifting bracket 1 at the top of the column 12 is as follows:

[0034] like Figure 5 and Figure 6 As shown, the lifting bracket 1 and the column 12 (preferably a steel tube concrete column) are modeled and calculated as a whole. The maximum lifting load is 940KN (the maximum reaction force of the hanging point is 938KN). The horizontal load is 5% of the vertical load, and the load partial coefficient is 1.4. As a result, the horizontal displacement of the top of the lifting bracket 1 is about 44mm; the downward deflection of the lifting end is about 18mm; and the maximum stress ratio of the rod is about 0.71<0.9, which meets the construction requirements.

[0035] like Figure 7 As shown, during the lifting process, the lower hanging point is subjected to a maximum load of 931KN (200-ton lower hanging device 7) and 453KN (60-ton lower hanging device 7). Considering a 1.4-fold load partial coefficient, through finite element analysis, the results show that except for some stress concentration, the stress at the lower hanging point is below 220MPa (the material of the hanging point is Q345B steel), which meets the lifting requirements.

[0036] like Figure 8 As shown, according to the lifting force analysis simulated by Midas software, multiple sets of lifting devices are evenly arranged on the top of the column.

[0037] The beneficial effects of the present invention are as follows: the present invention simplifies the form of the hanging points, eliminates three temporary rods, reduces the amount of measures for the temporary structure, and greatly reduces a large amount of high-altitude disassembly work after lifting into place, thereby saving construction time; the truss 9 is lifted as a whole to the designed elevation, and then the rods at the mating positions are welded and two sets of upper chords 14 are welded, which will greatly reduce the amount of high-altitude construction on site and the construction difficulty, thereby reducing construction costs.

[0038] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A lifting device for lower hanging points, which is symmetrically distributed around the circumference of the truss, characterized in that: The lower hanging point lifting device includes a lifting bracket, a hydraulic lifter, a steel strand, a hanging plate and two groups of connecting rods. The lifting bracket is fixed on the corbel at the top of the column, the hydraulic lifter is fixed on the lifting bracket, the hydraulic lifter pulls the steel strand upward, the hanging plate is fixedly connected to the lower end of the steel strand, the hanging plate is fixedly connected to the lower chord on the outside of the truss, the hanging plate and the hydraulic lifter overlap in the vertical direction, the two groups of connecting rods are located at the ends of the truss, one end of the connecting rod is fixedly connected to the middle part of the lower chord, the other end of the connecting rod is fixedly connected to the first steel ball on the outside of the truss, the connecting rod and the truss form a statically determinate structure, when hoisting, the connecting rod is used as a temporary hanging rod; when hoisted into place, the connecting rod is used as a reinforcing rod.

2. A lower suspension point lifting device according to claim 1, characterized in that: The hanging plate comprises a detachably connected plug plate and a hanger, wherein the plug plate is vertically inserted into the lower chord outside the truss, and the plug plate is fixedly connected to the lower chord, and the hanger is fixedly connected to the lower end of the steel strand.

3. A method for lifting the lower suspension point in an integrated manner, characterized in that: Using the lower suspension point lifting device described in claim 1 comprises the following steps: Fix the lifting bracket on the bracket at the top of the column, and install the hydraulic lifter and steel strand in sequence; Remove the two sets of upper chords on the outside of the truss, cut off the set length of the lower chord, vertically insert the plug plate into the lower chord at the end of the truss, and fix the plug plate to the lower chord, weld two sets of connecting rods, and fix the hanger to the lower end of the steel strand, and the plug plate and the hanger are detachably connected; The hydraulic lifters around the truss pull the steel strands upward, and the steel strands drive the truss to lift upward as a whole; The truss is lifted to the set elevation, and two sets of upper chords, cut sections of lower chords and truss end balls are repair-welded. At this time, the two ends of the upper chord are fixedly connected to the truss end balls and the first steel balls respectively. In the vertical direction, the truss end balls are opposite to the columns, and the central axis of the cut section coincides with the central axis of the lower chord.

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