Super-long fan-shaped space string truss steel roof and construction method thereof

Abstract

The invention discloses a super-long fan-shaped space string truss steel roof and a construction method thereof, and relates to the technical field of steel structure constructions.The super-long fan-shaped space string truss steel roof comprises herringbone columns, primary trusses and secondary trusses, the multiple primary trusses are communicated in a middle intersection area at intervals of one truss and intersect in pairs, and the secondary trusses are arranged in intervals of the primary trusses and cut off in the middle intersection area; the secondary trusses and the beam string structure form a combined system which is connected between the adjacent primary trusses to form a fan-shaped space structure; the bottom of the fan-shaped space structure is supported by a plurality of herringbone columns. The steel roof structure is high in stability, the construction scheme of ground pre-splicing, segmented hoisting and high-altitude butt joint is adopted, site limitation during splicing of the ultra-long fan-shaped steel roof is avoided, and the construction efficiency and quality are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of steel structure buildings, and in particular to an ultra-long fan-shaped space string truss steel roof and a construction method thereof. Background Art

[0002] At present, steel structure roofs are increasingly used in large-span industrial or civil buildings. Due to its large self-weight and large span, and the constraints of on-site construction conditions, the overall structure is a dangerous project exceeding a certain scale. The string truss has the characteristics of light weight, good load-bearing and easy construction, so the string truss is often used in steel structure roof projects. The string structure can be divided into a plane string structure and a space string structure according to the force. Among them, the space string structure can also be combined with other structures in the project to improve the structural force characteristics.

[0003] The sliding method and the overall lifting method (reverse method) are often used when installing steel roofs. However, when the on-site construction conditions are severely restricted, the lack of ground assembly space makes it difficult to select large machinery, and the entire roof truss is not in a unified plane, the above methods are not applicable in the project. When the steel roof design uses a secondary truss or other structure and a chord structure to form a combined system, the difficulty of controlling the installation accuracy increases, especially when the structure is an asymmetric structure and the main truss is a plane truss supported by the lower chord, there is no connection between the upper chords of the truss, forming a semi-open plane truss structure system, the out-of-plane stability is relatively weak, and the safety and reliability of the structure during construction and normal use are very high. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an ultra-long fan-shaped space string truss steel roof and a construction method thereof, which has strong structural stability and adopts a construction scheme of pre-assembly on the ground, segmented lifting and high-altitude docking, thereby avoiding the site limitations on site when assembling the ultra-long fan-shaped steel roof and ensuring construction efficiency and quality.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] In the first aspect, an embodiment of the present invention provides an ultra-long fan-shaped space tensioned truss steel roof, including herringbone columns, main trusses, and secondary trusses. A plurality of main trusses are connected at each interval in a central intersection and cross each other in pairs. The secondary trusses are arranged in the intervals of the main trusses and are cut off at the central intersection. The secondary trusses and the tensioned beams form a combined system connected between adjacent main trusses to form a fan-shaped space structure; the bottom of the fan-shaped space structure is supported by a plurality of herringbone columns.

[0007] As a further implementation, the main truss and the secondary truss are plane trusses, and there is no connection between the upper chords.

[0008] As a further implementation, the herringbone columns are connected to the lower chord of the main truss or the lower chord of the secondary truss, and the heights of the herringbone columns are not equal.

[0009] As a further implementation method, the connection angles and positions of each tension string beam and the truss beams corresponding to the main truss and the secondary truss are different.

[0010] As a further implementation method, the tension beam includes a chord, a strut and a cable, the strut is connected to the lower side of the secondary truss, the bottom end of the strut is connected to the cable through a locking clamp, the cable is connected to the main truss through an anchor, and the strut is connected between the main truss and the secondary truss.

[0011] As a further implementation method, a stiffening plate is provided at the connection between the column head of the herringbone column and the truss; the top of the herringbone column at the shear wall is connected to the main truss via a sliding spherical steel support.

[0012] In a second aspect, an embodiment of the present invention further provides a construction method of an ultra-long fan-shaped space string truss steel roof, comprising:

[0013] Install the herringbone column; install the main truss on the top of the herringbone column, using the same main truss to install from the middle node to both sides;

[0014] After the tensioning of the beam string is completed, it is pre-assembled with the secondary truss. After the pre-assembly, the beam string is hoisted, and the beam string and the secondary truss are installed from the inside to the outside and in accordance with the principle of symmetry of the main truss to form a fan-shaped space structure;

[0015] Unload the fan-shaped space structure as a whole.

[0016] As a further implementation method, multiple sections of main trusses are butt-jointed in the air through ear plate connection devices to form a whole main truss;

[0017] The fine-tuning of the main truss docking is completed by using a jack installed on an overhead support, and is achieved laterally using an assembly cradle on the support frame.

[0018] As a further implementation method, the beam string adopts two-stage tensioning, the first stage tensioning applies equivalent pre-tensioning force according to 50% of the cable force, and the second stage tensioning applies equivalent pre-tensioning force according to 100% of the cable force and over-tensioning by 5%.

[0019] As a further implementation method, the overall unloading process is: multiple jacks are hoisted to a temporary support platform and installed in the reserved space, and each jack performs multi-stage unloading simultaneously.

[0020] The beneficial effects of the present invention are as follows:

[0021] The ultra-long fan-shaped space string truss steel roof of the present invention, through the arrangement of herringbone columns and the spatial arrangement of trusses, fully utilizes the advantages of the string beam in bearing vertical loads and the good bending and shearing resistance of the truss structure, and also gives play to the advantages of using prestressed string to save steel consumption and improve the overall rigidity of the structure. It can be used in the case where the trusses of the entire roof are not in the same plane, and is suitable for the design of large-span complex steel roofs with large structural volume, irregular structural form, short structural construction period, and obvious time-varying effect.

[0022] The present invention adopts a construction scheme of pre-assembling on the ground and hoisting in sections before high-altitude docking, which avoids the site limitation when assembling the super-long fan-shaped steel roof and ensures the construction efficiency and quality; the main truss is installed from the middle node to both sides, and the installation principle is as symmetrical as possible, installed nearby, and the middle section is installed first and then the cantilever section. The tension beam and the secondary truss are installed from the inside to the outside and the main truss is symmetrical, which ensures the installation accuracy and ensures the safety and reliability of the structure during construction and normal use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0024] Figure 1 is a perspective view of the present invention according to one or more embodiments;

[0025] Figure 2 is a top view of the present invention according to one or more embodiments;

[0026] Figure 3 is a schematic diagram of a node of a herringbone column top according to one or more embodiments of the present invention;

[0027] Figure 4 is a schematic diagram of a top node of a herringbone column on a shear wall according to one or more embodiments of the present invention;

[0028] Figure 5 is a schematic diagram of a beam string structure according to one or more embodiments of the present invention;

[0029] Figure 6 Schematic diagram of the connection between a beam string and a secondary truss according to one or more embodiments of the present invention.

[0030] Among them, 1. A-shaped column; 2. Main truss; 3. Secondary truss; 4. Beam string; 5. Chord; 6. Strut; 7. Cable; 8. Column capital; 9. Column tube; 10. Stiffener; 11. Top plate of column; 12. Sliding spherical steel bearing; 13. Through-hole stiffener; 14. Locking clamp; 15. Anchor; 16. Ear plate; 17. Ear plate attached plate. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0032] Embodiment 1:

[0033] This embodiment provides an ultra-long fan-shaped space string truss steel roof, such as Figure 1 and Figure 2 As shown, a fan-shaped space structure is composed of several trusses. Every other truss is connected and crossed in pairs in the middle intersection area, and the other trusses are cut off in the middle intersection area, forming three groups of trusses in staggered overlap, similar to the unfolding structure of a folding fan; among them, every other truss that is connected and crossed in pairs in the middle intersection area is the main truss 2, and the truss arranged between the main trusses 2 and disconnected at the middle intersection is the secondary truss 3. The bottoms of the main trusses 2 and the secondary trusses 3 are respectively connected to multiple herringbone columns 1, and supported by the herringbone columns 1. The heights of the herringbone columns 1 are not equal, the starting positions of the installation are different, and they intersect with the main structure (truss structure), and the entire roof truss is not in a unified plane.

[0034] The main truss 2 system is a segmented structure, that is, it is composed of multiple segments of main trusses 2 spliced ​​along the length direction to form an ultra-long truss steel roof, and the specific number of segments is set according to actual conditions. Multiple segments of main trusses 2 are butt-jointed through ear plate 16 connection devices.

[0035] The main truss 2 is a plane truss supported by the lower chord, and there is no connection between the upper chords of the trusses, forming a semi-open plane truss structure system. The secondary truss 3 is also a plane truss, and the difference between it and the main truss 2 is that the secondary truss 3 is disconnected at the intersection of the main truss 2.

[0036] The steel roof of this embodiment adopts a combination system of secondary trusses 3 and beam string 4, and the connection angle and position of each beam string 4 with the truss beam are different. The beam string 4 is tensioned on the ground and pre-assembled with the secondary trusses 3.

[0037] The herringbone column 1 is formed by two cylindrical tubes 9 connected to form a herringbone structure, and the connecting ends of the two cylindrical tubes 9 are connected by a through-hole stiffening plate 13; the through-hole stiffening plate 13 is a stiffening plate 10 with a through hole, one end of the two cylindrical tubes 9 is inserted into the through hole, and is welded after being ground flat.

[0038] The column head 8 of the herringbone column 1 is connected to the lower chord of the corresponding main truss 2 and the lower chord of the corresponding secondary truss 3. Figure 3As shown, the bottom column head 8 of the herringbone column 1 is welded to the column tube 9, and the weld grade between the two is Grade I; the top column head 8 of the herringbone column 1 is connected to the truss with a stiffening plate 10, and the stiffening plate 10 is welded to the herringbone column 1 and the truss, and the weld grade is Grade I. Figure 4 As shown, a sliding ball steel support 12 is installed on the top of the herringbone column 1 at the shear wall through the column top plate 11, the sliding ball steel support 12 is connected to the column top plate 11 through anchor bars, and the sliding ball steel support 12 is connected to the bottom of the main truss 2.

[0039] like Figure 5 As shown, the tension beam 4 includes a chord 5, a strut 6 and a cable 7. The strut 6 is connected between the secondary truss 3 and its adjacent main truss 2. The strut 6 is supported at the bottom of the secondary truss 3. The top of the strut 6 is fixedly connected to the chord 5. A locking clip 14 is installed at the bottom of the strut 6. The cable 7 passes through the cable clip and both ends of the cable 7 are connected to the corresponding main truss 2 through locks. Figure 6 As shown, the main truss 2 is installed with an ear plate 16, and the ear plate 16 is welded and fixed to the main truss 2, and the weld grade is level one; the anchor 15 is connected to the ear plate 16 through a pin shaft, and an ear plate abutment 17 is installed at the connection.

[0040] Each truss (including the main truss 2 and the secondary truss 3) is butt-jointed along the length direction to form an ultra-long fan-shaped space string truss steel roof structure. With the string beams 4 connected between the trusses and the herringbone columns 1 at the bottom, the structure has strong stability.

[0041] The ultra-long fan-shaped space string truss steel roof of this embodiment fully utilizes the advantages of the string beam 4 in bearing vertical loads and the good bending and shearing resistance of the truss structure through the arrangement of the herringbone columns 1 and the spatial arrangement of the trusses, and also takes advantage of the use of prestressed string to save steel and improve the overall rigidity of the structure. It can be used in the case where the trusses of the entire roof are not in the same plane, and is suitable for the design of large-span complex steel roofs with large structural volume, irregular structural form, short structural construction period, and obvious time-varying effect.

[0042] Embodiment 2:

[0043] This embodiment provides a construction method for an ultra-long fan-shaped space string truss steel roof, based on the ultra-long fan-shaped space string truss steel roof described in Example 1, comprising the following steps:

[0044] Step (1) According to the design requirements, finite element simulation, tension calculation analysis, and unloading deformation calculation are performed on the steel roof.

[0045] Step (2) Installation of the herringbone column 1: The herringbone column 1 is installed after the steel beam bridge is hoisted. The step-by-step installation method is adopted, which includes ground assembly and installation with the tower crane of the main structure. After the steel column is manufactured and transported to the construction site, it is assembled. After the assembly is completed, it is tied, hoisted, and docked, and fixed after correction.

[0046] The assembly process of the middle herringbone column 1 is as follows: arranging the assembly frame; placing and assembling the column head 8 of the herringbone column 1 and the truss joint; assembling the column tube 9 of the herringbone column 1; and assembling the temporary support.

[0047] The step-by-step installation method is as follows: after the hoisting is completed, two supports are set in the middle of the herringbone column 1, and a cable wind rope is pulled. Before hoisting, the steel component should be placed horizontally on the pads. During hoisting, the component should not be dragged on the ground, and a certain height is required during rotation. The three actions of hooking, rotating, and moving are performed alternately and slowly, and the component is slowly lowered when in place to prevent scratching the bolt thread and the groove connected to the rigid beam by welding.

[0048] Step (3) Installation of the main truss 2: Use the same truss to install from the middle node to both sides, using the installation principles of symmetrical installation, installation nearby, and installation from low to high at the middle node. Start installation from the middle section and install the cantilever section outward in sequence. After the whole section is pre-assembled in the factory and transported to the site in sections, use a crane to hoist the main truss 2 to the support and temporarily fix it. Measure and calibrate the temporarily fixed main truss 2. After the calibration is qualified, connect and fix the support, and inspect and repair the nodes.

[0049] Furthermore, the main truss 2 is hoisted above the column surface, and then the truss is rotated with a stabilizing cable to align it with the support, so that the main truss 2 is accurately in place. The main truss 2 should be lowered slowly, and when the main truss 2 is about to contact the embedded bolts on the top surface of the column, the brake is suddenly applied to align it with the support bolts, and it is slowly hoisted into place, and the support holes are inserted into the bolts of the transition plate and initially tightened as a temporary fixation; and the truss is stabilized by a crane and must not be unhooked.

[0050] The fine adjustment of the high-altitude docking of the main truss 2 is completed by the jack installed on the high-altitude bracket, and the lateral direction mainly uses the assembly tire frame on the support frame to ensure the relative position of the components. The ear plate connection device is used to implement the aerial docking of the main truss between the two segmented main trusses. After the installation of the entire main truss is completed and tested, the final welding is carried out.

[0051] It should be noted that the ear plate connecting device is a prior art, which includes an ear plate and a connecting member (such as a bolt) connected to the ear plate.

[0052] Step (4) tensioning of the beam string 4: after processing in the factory, the beam string 4 is transported to the site in sections, and a single beam string 4 is assembled. The single beam string 4 assembled with the chord 5, the strut 6 and the cable 7 is placed on the assembly frame, and the single zipper is tensioned. This embodiment is divided into two stages of tensioning. The principle of the two stages of tensioning is: mainly based on force control, with the cable force control of the cable 7 as the main goal, and at the same time, the secondary beam mid-span vertical deformation is used as an auxiliary control to ensure that the force and shape are achieved, and finally it is consistent with the requirements of the initial design state. The first stage of tensioning applies an equivalent pre-tension force of 50% of the cable force, and the second stage of tensioning applies an equivalent pre-tension force of 100% of the cable force and exceeds the tension by 5%.

[0053] Step (5) Installation of the beam string 4, secondary trusses 3 and diagonal braces: After the tensioning of a single beam string 4 is completed, the chord 5 between the trusses is connected, the truss webs are installed, and the adjacent beam string secondary beams are pre-assembled. After the pre-assembly is completed correctly, the single beam string 4 is hoisted and installed one by one, following the principle of from the inside out and the symmetry of the main truss. After the installation is in place, the cable tension is monitored. If necessary, additional tensioning is carried out at high altitude. After all are completed, the diagonal braces are installed.

[0054] It should be noted that the installation of the truss web should be done after all 7 cables have been tensioned, then the lower chord stabilizing cable should be installed, and finally the roof cross tie rod should be installed.

[0055] Step (6) Overall unloading: The temporary support is unloaded using the screw jack unloading method, and the main structure is unloaded in stages using jacks. There are three levels of unloading, and the unloading amounts of each level are 10%, 30%, and 60% of the total vertical deflection of the corresponding unloading point, respectively.

[0056] Specifically, in the first step, after the unloading conditions are met, the jacks are hoisted to the temporary support platform and installed in the reserved space. A process gasket (polytetrafluoroethylene plate) is set on the top surface of the jack to tighten the support bottom plate. In the second step, each jack reverses the top structure until it is separated from the top surface of the first pad. After the first pad is pulled out, each jack falls synchronously to 10% of the total unloading amount of the corresponding unloading point, completing the first level of unloading. In the third step, each jack reverses the top structure until it is separated from the top surface of the second pad. After the second pad is pulled out, each jack falls synchronously to 30% of the total unloading amount of the corresponding unloading point, completing the second level of unloading. In the fourth step, repeat the above steps to complete the unloading step of the third level with 60% unloading amount, until the structure is completely separated from the temporary support. Remove the jacks, cut off the temporary support and grind the cut to make it smooth, and the unloading is completed.

[0057] The steel structure painting in this embodiment selects the on-site painting scheme of ground painting as the main method and high-altitude painting as the auxiliary method. Before the components are hoisted, except for the high-altitude welding and high-strength bolts, the rest are painted to the design requirements, and only the weld affected area and the part damaged by hoisting are repaired at high altitude.

[0058] This embodiment divides the long-span truss and the beam string 4 into different units, selects a nearby factory for processing, and welds and assembles them on the ground, which not only reduces the construction difficulty but also significantly reduces the transportation cost; a temporary high-altitude support platform is set up under the segment of the main truss 2 to meet the high-altitude positioning requirements of the segmented main truss 2; before the installation of the beam string 4, the main truss 2 is installed and verified to form a stable system to reduce the impact on the main truss 2; after all the cables are tensioned, the lower chord stabilizing cable is installed, and finally the roof cross rod is installed to reduce the prestress loss and the difficulty of high-altitude construction.

[0059] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An ultra-long fan-shaped space string truss steel roof, characterized in that: It includes herringbone columns, main trusses and secondary trusses. Multiple main trusses are connected at each interval and cross each other in the middle intersection area. Secondary trusses are arranged in the intervals of the main trusses and are cut off at the middle intersection area. The secondary trusses and the tension beams form a combined system connected between adjacent main trusses to form a fan-shaped space structure. The bottom of the fan-shaped space structure is supported by multiple herringbone columns.

2. The ultra-long fan-shaped space string truss steel roof according to claim 1 is characterized in that: The main truss and the secondary truss are plane trusses, and there is no connection between the upper chords.

3. The super-long fan-shaped space string truss steel roof according to claim 1 or 2, characterized in that: The herringbone columns are connected to the lower chord of the main truss or the lower chord of the secondary truss, and the heights of the herringbone columns are not equal.

4. The ultra-long fan-shaped space string truss steel roof according to claim 1 is characterized in that: The connection angle and position of each tension string beam with the corresponding truss beams of the main truss and the secondary truss are different.

5. The super-long fan-shaped space string truss steel roof according to claim 1 or 4, characterized in that: The tension beam comprises a chord, a strut and a cable, wherein the strut is connected to the lower side of the secondary truss, the bottom end of the strut is connected to the cable via a locking clamp, the cable is connected to the main truss via an anchor, and the strut is connected between the main truss and the secondary truss.

6. The ultra-long fan-shaped space string truss steel roof according to claim 1 is characterized in that: A stiffening plate is provided at the connection between the column head of the herringbone column and the truss; the top of the herringbone column at the shear wall is connected to the main truss through a sliding ball steel support.

7. A construction method for an ultra-long fan-shaped space string truss steel roof according to any one of claims 1 to 6, characterized in that: include: Install the herringbone column; install the main truss on the top of the herringbone column, using the same main truss to install from the middle node to both sides; After the tensioning of the beam string is completed, it is pre-assembled with the secondary truss. After the pre-assembly, the beam string is hoisted, and the beam string and the secondary truss are installed from the inside to the outside and in accordance with the principle of symmetry of the main truss to form a fan-shaped space structure; Unload the fan-shaped space structure as a whole.

8. The construction method of the super-long fan-shaped space string truss steel roof according to claim 7 is characterized in that: Multiple sections of main trusses are connected in the air through ear plate connection devices to form a whole main truss; The fine-tuning of the main truss docking is completed by using a jack installed on an overhead support, and is achieved laterally using an assembly cradle on the support frame.

9. The construction method of the super-long fan-shaped space string truss steel roof according to claim 7 is characterized in that: The beam string adopts two-stage tensioning. The first stage applies equivalent pre-tensioning force according to 50% of the cable force, and the second stage applies equivalent pre-tensioning force according to 100% of the cable force and over-tensions by 5%.

10. The construction method of the super-long fan-shaped space string truss steel roof according to claim 7 is characterized in that: The overall unloading process is as follows: a plurality of jacks are hoisted onto a temporary support platform and installed into a reserved space, and each jack performs multi-stage unloading simultaneously.

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