Hangar steel structure assembly construction process

Abstract

The application discloses a hangar steel structure assembling construction process, realizes large-span welding ball net rack, three-side supporting structure is frame column, and the construction adopts the comprehensive installation method of ground assembling and one-time integral lifting; the net rack has large span, and the difficulty of lifting synchronization control is large; the application of the mature technology solves the problem of large-span net rack lifting synchronization; professional calculation software is used, accurate calculation is carried out, the structure is reasonably reinforced, the requirements of net rack design specification, construction quality acceptance specification and the strength, rigidity and stability of the net rack itself are met; one-time integral lifting is realized, multi-point and multi-face flow operation can be formed, the engineering installation precision control is favorable, the synchronous control integral lifting can be effectively solved, the number of rear folding installation components is reduced to the maximum extent, the upper and lower anchor point positions of the roof steel structure are lifted and reinforced, and the installation precision in the assembling and lifting process of the large roof steel structure is measured and controlled.

Description

Technical Field

[0001] This invention relates to the field of steel structure assembly and construction technology, specifically to a hangar steel structure assembly and construction process. Background Technology

[0002] The construction of large-span space frames is challenging, and ensuring project safety, quality, and construction progress are crucial. Therefore, the selection of a construction scheme for hangar roof space frames is of paramount importance.

[0003] Currently, the following construction techniques are commonly used in the assembly and construction of hangar steel structures:

[0004] (1) Erect full-span red scaffolding and assemble at high altitudes.

[0005] This plan requires the erection of a large amount of scaffolding, and the on-site hoisting machinery layout is difficult to meet the requirements. In addition, it will have an adverse impact on the project progress and quality control. High-altitude operations are also very difficult in terms of project safety management.

[0006] (2) Ground assembly, segmented hoisting

[0007] The construction method of assembling the space frame into hoistable units on the ground and then hoisting them as a whole can form a simple assembly line operation. However, the assembly line operation between each process is monotonous, and the construction site needs to be equipped with many component assembly machines and large hoisting machines, which is detrimental to reducing project costs. In terms of project quality control, due to the increase in high-altitude docking units, it is also difficult to control the installation accuracy of the space frame.

[0008] (3) High-altitude installation of sliding support frame

[0009] The construction method of using sliding support frames for high-altitude installation can save some scaffolding, but due to the large weight of the gate frame, a large number of sliding support tools are needed, and the large amount of high-altitude closure makes safety protection difficult.

[0010] Based on the above solution, the following issues still need to be addressed:

[0011] 1) Overall improvement and synchronous control;

[0012] 2) How can we minimize the number of components required for the final assembly?

[0013] 3) Locations of the upper and lower anchor points for the roof steel structure lifting and reinforcement measures;

[0014] 4) Roof steel structure ground assembly method;

[0015] 5) The roof steel structure was lifted and closed as a whole;

[0016] 6) Measurement and control of installation accuracy during the assembly and lifting of the large roof steel structure.

[0017] This invention patent employs a single, integrated lifting method, enabling a large amount of work to be completed on the ground, reducing the amount of scaffolding and equipment required, avoiding high-altitude operations, and lowering the difficulty of safety management. It allows for multi-point, multi-faceted continuous operation, accelerating ground assembly progress, facilitating precise control of installation accuracy, and effectively solving the aforementioned technical problems. Summary of the Invention

[0018] To address the problems existing in the prior art, this invention provides a hangar steel structure assembly and construction process that enables large-span welded spherical grid frames with frame columns supporting three sides. The construction adopts a comprehensive installation method that combines ground assembly and one-time overall lifting.

[0019] 1) The large span of the space frame makes it difficult to improve synchronization control. This invention patent uses mature technology to solve the problem of improving synchronization of large-span space frames.

[0020] 2) Controlling the deformation of the space frame during the lifting process is very difficult. Professional calculation software is used to perform precise calculations to reasonably reinforce the structure. The lifting equipment is also designed and calculated in a reasonable manner to reduce construction deformation and meet the requirements of space frame design specifications, construction quality acceptance specifications, and the strength, stiffness, and stability of the space frame itself.

[0021] To achieve the above objectives, the present invention provides a hangar steel structure assembly and construction process, which specifically includes the following steps:

[0022] Step 1: Embedded parts installation, which includes the installation of embedded parts at the top of concrete frame columns, the installation of embedded bolts, and the installation of embedded parts for inter-column supports.

[0023] Step 2: Install the inter-column bracing. The inter-column bracing is bolted to the nodes on the concrete columns on both sides and welded to the support ball in the middle. Since the inter-column bracing is too long, the inter-column bracing is connected by a connecting plate. During installation, the middle connecting plate is first fixed with a temporary support, and then each inter-column bracing is hoisted separately. One side is temporarily connected to the node with ordinary bolts, and the other side is spot welded to the welding ball. After adjusting to the design elevation, the side connected with ordinary bolts is replaced with high-strength bolts, and the side that was spot welded is fully welded.

[0024] Step 3: Space frame assembly construction. Assemble the space frame on the ground plane in the middle of the site. After the assembly jig is made, the space frame extends from the middle to both sides grid by grid. First the lower chord, then the upper chord, then the lower chord. The lower chord sphere must be on its projection line.

[0025] Install the lower chord balls and poles of the first span to form a longitudinal planar grid, arrange the leveling support points to ensure the parallelism of the lower chord balls, and find the bottom of the slope at the temporary support points when the grid is arched;

[0026] On the premise of ensuring the flatness of the ground for assembling the space frame, horizontal support points are set on the ground according to the relative elevation of the lower chord ball. The elevation of the horizontal support points is measured with a level to ensure that they are at the same elevation. After the elevation of the horizontal support points is determined, they should be marked accordingly. During this period, the support points should not be moved at will. In addition, the elevation of the support points should be checked with a level every day before construction to ensure that the elevation is accurate and to ensure the flatness of the lower chord ball.

[0027] Step 4: The entire steel structure of the space frame is lifted. The space frame is lifted in two stages. The first stage is a 3-meter lift to install the lower truss of the gate. The second stage is a complete lift of the roof space frame. After the lift is completed, the members are installed and then unloaded one by one. The upper lifting support is set on the top of the original structural column, and the lower suspension point structure is a temporary support and a suspension point ball structure.

[0028] Preferably, in step 1, the method for embedding the pre-embedded parts at the top of the concrete frame column is as follows: First, the control line for the pre-embedded part position and the elevation line of the bottom plane should be measured and set. Before embedding the pre-embedded parts, each group of pre-embedded parts should be fixed to the pre-embedded plate and connected into a whole by a rigid frame. After the civil engineering unit has finished pouring the bottom plate, the bolt bracket should be in place before the steel reinforcement is tied at the pre-embedded bolt. The bracket should be positioned and supported firmly by a temporary reinforcement mechanism so that it matches the axis and elevation. The entire bracket should be embedded before the steel reinforcement is tied. After it is fixed, the civil engineering unit will tie it.

[0029] The method for installing the embedded bolts is as follows: After the concrete of the column below the embedded part is poured, the embedded part can be inserted. A preliminary check of the embedded part is then performed. Based on the measured axis, the embedded bolts are positioned as a whole. First, the longitudinal and transverse center lines of the four fixing angle steels on the upper part of the embedded part are accurately located (measured and marked in advance) and aligned with the baseline for measurement and positioning. Then, a level is used to measure the marks on the top surfaces of the bolts at the four corners of the embedded part. If the height is insufficient, steel bars or angle steel are used to level the bolts at the four corners of the four fixing angle steels below the embedded part.

[0030] The method for embedding inter-column supports is as follows: the embedded parts can be inserted during the construction of the concrete frame column reinforcement; during embedding, close coordination with the civil engineering reinforcement and formwork sections is required. During reinforcement construction, the embedded iron can be fixed to the concrete wall reinforcement mesh; during formwork construction, the verticality of the embedded plate can be accurately corrected; and during concrete construction, continuous adjustments can be made to ensure the embedding accuracy.

[0031] Preferably, in step 3, the space frame assembly platform is composed of an adjustable steel tire support;

[0032] The cambering of the assembly is designed based on the maximum deflection value of the original space frame. The cambering value at each point of the lower chord sphere of the space frame is calculated based on the cambering value. The cambering of the space frame is achieved by adjusting the length of the positioning steel pipe under the space frame assembly support.

[0033] The camber value of each point on the lower chord sphere of the space frame is different, so it is necessary to accurately measure the actual elevation of the assembly jig for each lower chord sphere to ensure the geometric dimensions of the space frame; the processing accuracy of the branch pipes requires the error to be controlled within ±1mm.

[0034] Preferably, the method for assembling the space frame in step 3 is as follows: Step A: Set and level the support frame, install the lower chord ball on the top of the support frame, and connect the lower chord balls with the lower chord rod;

[0035] Step B: The lower chord members form a unit with two rectangles. The web members and upper chord ball are installed in the first unit. The first cone is a small unit with one ball and four web members. After it is in place, it is connected and fixed to the lower chord ball.

[0036] Step C: The second cone starts by installing a triangular cone with one ball, one chord, and two web members, and then filling in the other two web members, gradually cyclically installing the first unit of the space frame;

[0037] Step D: Starting from the second unit of the space frame, the installation and assembly are carried out using a side-by-side method. Beginning from the side span, first install a triangular pyramid with one ball, one upper chord, and two web members, followed by a quadrangular pyramid with one ball, two upper chords, and two web members. Support the two diagonal web members on the lower chord ball, tighten the upper chord ball above, and gradually bring the upper chord ball closer to the installation position, filling in the upper chord members.

[0038] Preferably, in step 3, the assembly of the hangar gate frame and the hangar door node in the width direction of the frame is carried out by welding steel sections, and the fixed end is connected to the steel balls on both sides by connecting plates at the welded ball nodes on both sides. The lower end of the steel section is opened with a round hole, which constitutes the upper hanging beam system of the whole door.

[0039] Preferably, in step 4, the overall lifting step of the space frame steel structure is designed as follows: (1) Lifting point arrangement: 12 lifting points are arranged during the first lifting of the roof space frame, and 10 lifting points are arranged for the second lifting; (2) Upper lifting frame arrangement: Since the concrete column section at the top of the steel column is relatively small, a corbel steel structure is set in the column top support structure; (3) Lifting lower suspension point setting: Lifting point balls are set at the position of the oil cylinder of the column top support, which serve as anchoring devices for the steel strands. Temporary support rods are used to connect the lifting point balls and other welded ball nodes of the space frame. The connected welded ball nodes are determined by calculation; (4) Temporary lifting support setting: Since the three-layer space frame above the gate has one more layer than the hall, it is necessary to first assemble the upper two layers of the space frame and then lift it as a whole by 3m before assembling the remaining third layer of members. During the lifting, the space frame at the gate position only has two layers and does not form a whole. Because the deformation is relatively large during the lifting, two sets of temporary lifting points need to be added at the gate position. The lifting point support and the gate ground beam are connected with chemical anchor bolts.

[0040] In summary, this invention provides a hangar steel structure assembly and construction process that enables a single, overall lifting operation. All assembly work can be completed on the ground, reducing the amount of scaffolding and equipment required, avoiding high-altitude work, and lowering the difficulty of safety management. It allows for multi-point, multi-faceted continuous operation, accelerating ground assembly progress, facilitating precise control of installation accuracy, effectively solving the problem of synchronous control of the overall lifting, minimizing the number of components required for subsequent assembly, and enabling measurement and control of installation accuracy during the assembly and lifting of the large roof steel structure, including the positioning of the upper and lower anchor points and reinforcement work. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the overall construction process of the steel structure of the present invention;

[0042] Figure 2 This is a schematic diagram of the overall embedding of the pre-embedded parts of the present invention;

[0043] Figure 3 This is a schematic diagram of the embedded part reinforcement structure of the present invention;

[0044] Figure 4 This is a schematic diagram of the inter-column support installation of the present invention;

[0045] Figure 5 This is a schematic diagram of the adjustable steel tire support structure of the present invention;

[0046] Figure 6 This is a schematic diagram of the tire frame support distribution of the present invention;

[0047] Figure 7 This is a schematic diagram of the lower chord ball installation of the present invention;

[0048] Figure 8 This is a schematic diagram of the installation of the lower chord of the present invention;

[0049] Figure 9 This is a schematic diagram of the installation of the web rod and the upper chord ball between the first units of the present invention;

[0050] Figure 10 This is a schematic diagram of the connection between the upper chord and web members of the second grid between the first units of the present invention;

[0051] Figure 11 This is a schematic diagram showing the installation of the first unit of the present invention.

[0052] Figure 12 This is a schematic diagram of the installation between the second unit of the present invention. Figure 1 ;

[0053] Figure 13 This is a schematic diagram of the installation between the second unit of the present invention. Figure 2 ;

[0054] Figure 14 The present invention assembles the components into a more stable basic unit;

[0055] Figure 15 The present invention enables the assembly of the space frame on the ground;

[0056] Figure 16 This is a schematic diagram of the installation of the gate frame and hangar door nodes of the present invention;

[0057] Figure 17 This is a schematic diagram of the pillar top support at the gate position of the present invention;

[0058] Figure 18 This is a schematic diagram of the column top support in the lobby location of the present invention;

[0059] Figure 19 This is a schematic diagram of the hanging point structure in the lobby of the present invention;

[0060] Figure 20 This is a schematic diagram of the lower suspension point structure at the gate position of the present invention;

[0061] Figure 21 This invention relates to a temporary lifting bracket for the gate position;

[0062] Figure 22 This is a schematic diagram of the installation of the non-lifting point rod at the gate position during the first lifting of the gate position according to the present invention;

[0063] Figure 23 This is a schematic diagram of the installation of lifting points 1 and 10 of the present invention;

[0064] Figure 24 This is a system diagram of the lifting synchronization control diagram of the lifting cylinder of the present invention;

[0065] Figure 25 This is a diagram of the computer synchronous control lifting cylinder system of the present invention. Detailed Implementation

[0066] The invention will now be further described with reference to the accompanying drawings.

[0067] like Figures 1 to 25 As shown:

[0068] This invention relates to a steel structure assembly construction process for hangars. The roof structure employs a two-layer inclined quadrangular pyramidal steel space frame supported by the lower chord. The main grid dimensions are 4.5×4.5m, with a height of 4.85m. The space frame nodes are welded hollow spherical nodes. The roof at the hangar entrance uses a three-layer inclined quadrangular pyramidal steel space frame, with the center elevation of the lower chord of the space frame at 24m and the center elevation of the lower chord of the entrance at 21m.

[0069] like Figure 1As shown: Due to the large-span space frame construction involved, this project is extremely challenging. Ensuring project safety, quality, and timely completion are crucial; therefore, the selection of the hangar roof space frame construction plan is of paramount importance. The assembly construction method employs the following method: the lobby space frame and the entrance space frame are assembled separately on the ground, with the entire space frame then being lifted to the design elevation for the final assembly.

[0070] Embedded parts on the top of concrete frame columns: First, the control line (base axis or center line) and the elevation line of the bottom plane of the embedded parts should be measured and set.

[0071] Before embedding the embedded parts, fix each group of embedded parts to the embedded plate and connect them into a whole through a rigid frame. After the civil engineering unit has finished pouring the base plate, put the bolt bracket in place before binding the reinforcing bars at the embedded bolts. Then, use a temporary reinforcement mechanism (scaffolding steel pipes or reinforcing bars) to position the bracket and support it firmly so that it matches the axis and elevation. The entire bracket should be embedded before binding the reinforcing bars. After it is fixed, the civil engineering unit will then bind it.

[0072] Embedded part construction steps:

[0073] (1) Measurement and layout: First, based on the original axis control points and elevation control points, the axis and elevation control points on site are densified. Then, based on the axis measured and laid out by the control lines, the center cross line of each embedded part and at least two elevation control points are measured and laid out.

[0074] (2) Figure 2 As shown, the pre-embedded bolt frame is fabricated in the factory. L80×50×6 angle steel is used to fix the pre-embedded bolts into a single unit. The fabrication precision of the pre-embedded bolts is as follows: the center-to-center spacing of the pre-embedded bolts is ≤2mm, and the relative height difference between the tops of the pre-embedded bolts is ≤2mm.

[0075] Installation of pre-embedded bolts:

[0076] Specifically, such as Figure 3 As shown, after the concrete pouring of the column below the embedded part is completed, the embedding work can begin. Initial alignment of the embedded part is then performed. Based on the measured axis, the embedded bolts are positioned as a whole. First, the longitudinal and transverse center lines of the four fixing angle steels on the upper part of the embedded part are accurately located (pre-measured and marked), ensuring they align with the measurement and positioning baseline. Then, a level is used to measure the marks on the top surfaces of the bolts at the four corners of the embedded part. If the height is insufficient, steel bars or angle steel are used to level the four corners of the four fixing angle steels below the embedded part. During installation, steel bars with a diameter of at least φ20 are used to support the embedded part on the surrounding formwork or steel bars, as well as on the concrete, to position and fix the embedded part.

[0077] After the initial alignment of the embedded parts is completed, the binding of the reinforcing bars in the beams can begin. Once all the reinforcing bars are bound, the embedded parts of the formwork support should be checked again before pouring to ensure that their position and elevation are accurate and securely fixed before proceeding with the pouring process. Before pouring concrete, the threads should be coated with grease and wrapped with oil paper, and then a sleeve should be installed on the outside.

[0078] Pre-embedded parts for inter-column supports: The installation of pre-embedded parts for inter-column supports is similar to that of pre-embedded parts for column tops. The pre-embedded parts can be inserted during the construction of the concrete frame column reinforcement.

[0079] During installation, close coordination with the civil engineering reinforcement and formwork sections is essential. During reinforcement construction, the embedded iron can be fixed to the concrete wall reinforcement mesh. During formwork construction, the verticality of the embedded plate can be precisely corrected. During concrete construction, continuous adjustments can be made to ensure the accuracy of the embedded parts.

[0080] For certain special embedded parts, to ensure installation accuracy, they can be installed after the concrete wall has been poured to their designated positions. During installation, the wall top plate should be leveled first, then the embedded part should be placed on the plate, and the horizontality of the embedded part should be corrected using tools such as shims. Verticality can be adjusted by welding angle steel onto the embedded plate for positioning.

[0081] Pre-embedded quality control

[0082] (1) The accuracy of the embedded parts of the steel column foundation directly affects the installation quality and progress of the steel column. Therefore, before the steel column is hoisted, the axis, elevation and extension length of the embedded bolts that have been installed must be carefully checked and accepted. For those that do not meet the specifications, the supervisor and relevant parties should be asked to resolve the issue together.

[0083] (2) For embedded parts that are bent and deformed, they should be corrected; the threads should be cleaned, damaged threads should be repaired, and all embedded bolts should be protected.

[0084] (3) The elevation pads should be placed under the stiffening ribs of the column base plate near the embedded parts. Before the concrete is poured, the pads should be fixed by welding.

[0085] (4) The elevation adjustment is carried out in two steps using overlapping blocks. First, four sets of blocks are evenly distributed at the bottom of the steel column. At this point, the elevation has been initially adjusted. After the steel column is in place, it is adjusted again as needed. After the inspection is completed, other blocks are added.

[0086] Inter-column bracing installation method

[0087] like Figure 4As shown: The inter-column bracing is fabricated as a whole in the factory and transported to the site. It is then hoisted into place using a 25t truck crane. The two sides are bolted to the nodes, and the middle is welded to the support ball. Due to the excessive length of the inter-column bracing, the inter-column bracings are connected by connecting plates. During installation, the middle connecting plate is first fixed with temporary supports, and then each inter-column bracing is hoisted separately. One side is temporarily connected to the node with ordinary bolts, and the other side is spot-welded to the support ball. After adjusting to the design elevation, the side connected with ordinary bolts is replaced with high-strength bolts, and the spot-welded side is fully welded.

[0088] This invention relates to a flat space frame with large grid dimensions and sag. Given the tight schedule, numerous welding points, and the difficulty in controlling welding deformation, coupled with the heavy workload, and after comprehensive consideration of cost, schedule, construction quality, and safety, our company will adopt a ground-based, modular lifting method to address the large span and heavy components of this space frame. The operational process is as follows: Laying out the lines → Installing the lower chord grid of the hall → Installing the upper chord grid of the hall → Installing the lower chord grid of the main entrance → Adjustment and tightening → Lifting, edge sealing, and positioning → Welding and acceptance of supports.

[0089] Assemble the space frame on the central ground level. After the assembly jig is completed, extend the space frame from the center outwards grid by grid, starting with the lower chord, then the upper chord, and finally the lower chord again. The lower chord sphere must be on its projection line. Install the lower chord plane space frame, using a theodolite and measuring tape to align the column top axis and center line, and use a level to check the elevation. Any errors should be corrected.

[0090] Install the lower chord balls and rods in the first span to form a longitudinal planar grid. Arrange the leveling support points to ensure the parallelism of the lower chord balls. When the grid structure arches, the bottom of the slope should be found at the temporary support points.

[0091] The height error of the lower string ball is a key control point in this part of the work.

[0092] First, ensure the ground for assembling the space frame is flat. Then, based on the relative elevation of the lower chord sphere, set up horizontal support points on the ground. Use a level to measure the elevation of the horizontal support points to ensure they are at the same elevation. After the horizontal support points are positioned, they should be marked accordingly. During this period, these support points should not be moved arbitrarily. In addition, the elevation of the support points should be checked with a level every day before construction to ensure that the elevation is accurate and to guarantee the flatness of the lower chord sphere.

[0093] like Figure 5 As shown:

[0094] Assembly platform construction: The center horizontal elevation of the lower chord of the space frame is uniformly set at +0.80m above the ground for easy worker operation. The assembly platform consists of an adjustable steel frame.

[0095] Assembling and cambering: The cambering value of the space frame is designed based on the maximum deflection value of the original design. The cambering value at each point of the lower chord sphere of the space frame is calculated based on the cambering value. The calculated cambering value of the maintenance hangar space frame is 175mm. The cambering of the space frame is achieved by adjusting the length of the positioning steel pipe under the space frame assembly support.

[0096] The camber value of each point on the lower chord sphere of the space frame is different. Accurate measurement of the actual elevation of the assembly jig for each lower chord sphere is crucial to ensure the geometric dimensions of the space frame. The processing of the branch pipes must meet precision requirements, with errors controlled within ±1mm.

[0097] Space frame assembly

[0098] The space frame is assembled starting from the middle along the span, then extending to both sides. The lower chord is assembled first, followed by the web members and middle chord, and then the upper chord. The assembly sequence is as follows: Figure 6-15 As shown:

[0099] The specific ground assembly steps are as follows: (1) As Figure 6-8 As shown: Set and level the jig support, and install the lower chord ball on the jig support. (2), as shown Figure 9 As shown: Install the web members and upper chord ball between the first unit. Generally, the first unit is a small unit with a cone, a ball, and four web members. After it is in place, it is connected and fixed to the lower chord ball.

[0100] (3) Figure 10-13 As shown, the second cone-shaped structure is installed by first installing a triangular cone with one ball, one chord, and two web members, and then filling in the other two web members, gradually cyclically installing the first unit of the space frame; check the dimensions of the space frame and grid, and check the longitudinal dimensions and sag of the space frame. Check the position of the space frame; if there are discrepancies, adjust the position and height of the temporary supports to calibrate the position and dimensions of the space frame.

[0101] (4) Figure 14 , 15 As shown: Starting from the second unit of the space frame, the installation and assembly adopts a side-by-side method. Beginning from the side span, a triangular pyramid with one ball, one top chord, and two web members is first installed, followed by a quadrangular pyramid with one ball, two top chords, and two web members. The two diagonal web members are supported on the bottom chord ball, and the top chord ball is tightened above, gradually bringing the top chord ball closer to the installation position and filling it into the top chord member.

[0102] When assembling the space frame on the ground, a measurement needs to be taken after each unit of the space frame is assembled. During the installation of the steel space frame, the assembly error of the steel space frame must be measured and controlled at all times. If any indicator exceeds the control range, the cause must be found out and corrected immediately.

[0103] Permissible deviations after steel space frame assembly (unit: mm)

[0104]

[0105] like Figure 16As shown: When assembling the hangar gate frame, attention must be paid to the treatment of the joints between the gate frame and the hangar door. The method involves welding H250*250*9*14 steel, with the fixed ends consisting of connecting plates at the welded ball joints on both sides, which are welded to the steel balls on both sides. A 22mm diameter circular hole is drilled at the lower end of the H-shaped section; the hole location is provided by the door manufacturer. This is installed along the 87m width of the steel frame, forming the overall upper beam system for the door. The hangar door is then fixed to these members.

[0106] Overall steel structure lifting scheme: The hangar roof has a plan dimension of 90m × 72m. The roof structure adopts a two-layer inclined four-corner pyramid space frame, supported on three sides and open on one side, with a large door on the open side. The basic grid size is 4.5 × 4.5m. The space frame nodes are welded hollow spherical nodes.

[0107] The roof space frame adopts a "ground assembly, overall lifting" construction scheme. The space frame is lifted in two stages: the first lift is 3 meters to install the lower truss of the main gate, and the second lift is the entire roof space frame in place. After lifting, the supporting members are installed and then unloaded one by one. The upper lifting support is set on the top of the original structural columns, and the lower suspension point structure consists of temporary supports and a ball-shaped suspension point structure.

[0108] The roof weighs approximately 570 tons. The first lifting operation uses 12 lifting points: two 100-ton hydraulic cylinders each at lifting points 1 and 10, and one 100-ton hydraulic cylinder at each of the remaining lifting points, for a total of 14 100-ton hydraulic cylinders. The second lifting operation uses 10 lifting points: four 100-ton hydraulic cylinders each at lifting points 1 and 10, and one 100-ton hydraulic cylinder at each of the remaining lifting points, for a total of 16 100-ton hydraulic cylinders.

[0109] Lifting point layout:

[0110] For the first lifting of the roof truss, 12 lifting points were set up. Lifting points 1 and 10 each had two 100t hydraulic cylinders, and each of the remaining lifting points had one 100t hydraulic cylinder, for a total of 14 100t hydraulic cylinders. For the second lifting, 10 lifting points were set up. Lifting points 1 and 10 each had four 100t hydraulic cylinders, and each of the remaining lifting points had one 100t hydraulic cylinder, for a total of 16 100t hydraulic cylinders.

[0111] The present invention relates to the arrangement of lifting cylinders, which involves four hydraulic pump stations with a flow rate of 80L / min. Each 80L / min pump station is a dual-pump, dual-proportional-valve, dual-path hydraulic pump station, and the two paths can be used independently or in combination.

[0112] Hydraulic Cylinder Performance Table

[0113]

[0114] Steel strand performance table

[0115]

[0116] Upper lifting frame design: Due to the relatively small cross-section of these concrete columns at the top, corbels are required in the support structure at these column tops. For example... Figure 17 , 18 As shown: Lifting brackets are installed on the top of both the column and the corbel steel structure at the gate location to cooperate with the installation of the lifting device. The lifting brackets and the lifting device form the lifting system for the gate installation.

[0117] like Figure 19 , 20 As shown: Lifting point design: A lifting point ball is set at the position of the hydraulic cylinder of the column top support, which serves as the anchoring device for the steel strand. Temporary support rods are used to connect the lifting point ball to other welded ball nodes of the space frame. The connected welded ball nodes are determined by calculation.

[0118] As shown in Figure 21: Temporary lifting support design: Since the three-layer space frame above the gate has one more layer than the hall, it is necessary to first assemble the upper two layers of space frame and then lift the whole structure by 3m before assembling the remaining third layer of members. During the lifting, the space frame at the gate position only has two layers and is not formed as a whole. Because the deformation is relatively large during the lifting, two sets of temporary lifting points need to be added at the gate position. The lifting point supports and the gate ground beam are connected with chemical anchor bolts.

[0119] Main steps for lifting the space frame:

[0120] (1) Install all column top supports and install lifting brackets and lifting equipment;

[0121] (2) Assemble the space frame structure on the ground. First assemble the first and second layers of the space frame at the gate, and then install the lower suspension point structure.

[0122] (3) Install two sets of temporary lifting support structures and lifting equipment at the gate location;

[0123] (4) Use lifting equipment to lift the assembled space frame structure to a height of 3 meters;

[0124] (5) Install the third-layer space frame at the gate location. The installation sequence of the third-layer space frame is as follows: First, install the members at the non-lifting point locations (first the middle of the span, then the two sides). After the members are installed, temporarily place them on the ground. Then, transfer the lifting force of the two sets of column tops and two sets of temporary lifting brackets at the gate location to the ground support points. After the lifting force transfer is completed, remove the two sets of temporary lifting brackets and the lower suspension point structure on both sides at the gate location. Finally, install the remaining members and the new lower suspension point structure at the gate location.

[0125] (6) Use 12 column-top lifting equipment to lift all the assembled space frame structures to the design elevation.

[0126] (7) Install the supporting members around the column top supports, unload and dismantle the lifting equipment and brackets. The order of installing the supporting members is as follows: First, install the supporting members around the tops of the columns at non-lifting points (a total of 12 columns). Then, install the supporting members around the tops of the 8 columns at the lifting points in the lobby. Each of the 8 columns must have its lifting force unloaded and supporting members installed individually; multiple columns or a single column cannot have their lifting force unloaded and supporting members installed at the same time. Finally, install the supporting members around the tops of the 4 columns at the lifting points of the main gate.

[0127] Installation steps for the third layer of support members at the main gate:

[0128] Step 1: After the first lifting into place, install the rods at positions other than the lifting point.

[0129] Step Two: As Figure 22 As shown, the space frame is temporarily placed on the ground, with 8 temporary support points in the middle of the span. The support members are D180×8, and the length of the members is determined according to the site layout. At the gate position, the installed member node balls are temporarily placed on the ground. After the lifting points 1, 10, 11, and 12 are unloaded, the lifting points are removed.

[0130] Step 3: As Figure 23 As shown: the remaining rods at the installation location of the gate and the structure of the lower suspension points 1 and 10.

[0131] To determine the lifting points, the following measures were taken:

[0132] (1) The overall structural area to be lifted is large, the steel structure is complex, and the stiffness of the members varies greatly. The key to the lifting construction plan is to arrange the lifting points reasonably, ensure the safety of the lifting construction and that the stress and deformation of the lifted components are within the allowable range of the specifications.

[0133] Using computer-aided finite element analysis software, various lifting construction conditions were sequentially simulated. Combined with the engineering design, calculations and analysis were conducted to ensure the structural stress ratio was below 0.5, thereby determining the optimal lifting point locations and the required lifting force. Through calculation, analysis, and optimization, it was ultimately determined that 12 lifting points would be used for the first lifting operation, and 10 lifting points for the second lifting operation.

[0134] (2) The lifting structure has a large area, a high lifting height, and high safety requirements. The planar dimensions of the lifting steel structure are 90m × 72m, with an area of ​​approximately 6480m². 2 It has a large area. The concrete columns are 23.5m high.

[0135] 1) Multiple lifting cylinders were used. The first time, 14 lifting cylinders (100 tons each) were deployed at 12 lifting points; the second time, 16 lifting cylinders (100 tons each) were deployed at 10 lifting points. A control system with strong control capabilities was selected, capable of coordinating the actions of the 16 lifting cylinders and 4 hydraulic pump stations.

[0136] 2) Install inter-column supports. Before lifting, install the concrete inter-column supports to increase the stability of the columns.

[0137] 3) Appropriately increase the safety factor. The total lifting capacity of the 16 lifting cylinders is 1600 tons, the overall safety reserve factor of the lifting cylinders is 3.85, and the safety factor of the steel strand is 9.02.

[0138] (3) The load at each point on the same lifting platform fluctuates greatly during the lifting process. On the same column top, the distance between each lifting point is close, the structural stiffness is high, and it is extremely sensitive to position synchronization control. As long as the position error changes slightly, the load at each point will be redistributed and fluctuate greatly, which may cause structural insecurity.

[0139] 1) Adopting a control strategy that combines position synchronization and load distribution, a load distribution synchronization control strategy is adopted between each lifting point at each column top during the design of the computer control system software, so that the load of each lifting point at each column top position of the lifting structure is basically consistent with the theoretical calculation.

[0140] 2) At each lifting point, a high-precision pressure sensor is selected, with a measurement accuracy within 0.5%.

[0141] 3) Use a high-precision computer control system.

[0142] (4) In order to achieve high precision in synchronous control, the synchronous error between each lifting point should be controlled within 10mm during the lifting process. At the same time, the load of each lifting point on the same column top should be controlled within the range that is basically consistent with the theoretical calculation.

[0143] 1) A position synchronization control strategy is adopted. In the design of the computer control system software, a position synchronization control strategy is adopted among the 12 column top lifting points, and the synchronization error is controlled within ±5mm to ensure that the position of the lifting structure is synchronized.

[0144] 2) When measuring the position of the steel structure, a 20-meter long-distance sensor is used, and the measurement accuracy can reach 0.25mm.

[0145] 3. The lifting hydraulic system uses imported proportional valves with high synchronous adjustment accuracy to control the lifting speed.

[0146] (5) Due to the long suspension time in the air, after the steel structure is raised 3m, it needs to be suspended in the air for about three days before the installation of the third layer of steel structure for the gate. After the steel structure is raised into place, it needs to be suspended in the air for about a week before the additional rods are installed.

[0147] 1) Mechanical locking. The load is transferred to the lower anchor, the lifting cylinder enters its safe stroke, and the upper anchor is locked. Additionally, a safety anchor is added to the lower part of the lifting cylinder to ensure safety.

[0148] 2) Wind protection measures. Wooden wedges are installed between the columns and the space frame during the structure's suspension period to prevent swaying due to wind load.

[0149] 3) During the suspension period, all construction welding machines should be in double-line position to prevent arc damage to the lifting steel strands.

[0150] (6) The steel structure is close to the column spacing during the lifting process.

[0151] During the lifting process of the steel structure, the average distance between its columns and the lower suspension point node ball is only 5cm; therefore, the installation of the lifting equipment must ensure high positioning accuracy. The method adopted is to first install the lifting platform lifting cylinder based on the actual position of the column top suspension point, and then, based on the actual position of the lifting platform, lower suspension point node ball positions are positioned by casting downwards, ensuring accurate positioning of the lifting ground anchor plate and lifting cylinder during installation, with the vertical error between the two controlled within 5mm.

[0152] The overall lifting speed was controlled to prevent the lifting structure from swaying and impacting the anti-collision columns. A lifting guide device was also specially installed as an auxiliary measure to ensure smooth lifting.

[0153] Computer-controlled hydraulic synchronous lifting system: It consists of several parts, including steel strands and lifting cylinder clusters (load-bearing components), hydraulic pump station (drive components), sensor detection and computer control (control components), and remote monitoring system.

[0154] The steel strands and lifting cylinders are the load-bearing components of the system, used to support the weight of the lifting components. Users can configure the number of lifting cylinders according to the lifting weight (lifting load), and cylinders can be used in parallel at each lifting point.

[0155] The steel strands are high-strength, low-relaxation prestressed steel strands with a nominal diameter of 15.24 mm and a tensile strength of 1860 N / mm². 2 The breaking tensile strength is 260.7 kN, the minimum load at 1% elongation is 221.5 kN, and the weight per meter is 1.1 kg. The steel strand conforms to the international standard ASTM A416-87a, and its tensile strength, geometric dimensions, and surface quality are strictly guaranteed. Advanced design methods (digital technology and finite element analysis technology) and strict quality control measures are employed to ensure the absolute safety of the lifting cylinder.

[0156] The lifting cylinder features a through-core structure, and its production process is strictly controlled according to ISO9000 quality standards. Each lifting cylinder undergoes rigorous testing in the factory, primarily including functional and durability tests. In international projects, the lifting cylinders have passed stringent testing standards in the United States and Germany.

[0157] The characteristics of the lifting cylinder are as follows:

[0158] 1) The seals adopt German technology, which effectively ensures the sealing performance of the lifting cylinder, thereby improving the working reliability of the lifting cylinder;

[0159] 2) The modular design allows for easy replacement in case of malfunctions, ensuring the smooth progress of the project;

[0160] 3) Install a pressure and speed control valve in the lifting cylinder to ensure that the cylinder descends smoothly and safely under load;

[0161] 4) The lifting cylinders can also be used in combination. Two lifting cylinders can be combined to form one continuous lifting cylinder.

[0162] The hydraulic pump station is the power drive part of the lifting system. The use of proportional synchronization technology in the hydraulic system can effectively improve the synchronization and adjustment performance of the entire system.

[0163] Improve synchronization control, such as Figure 24 As shown, the computer synchronous control system is as follows: Figure 25 As shown;

[0164] Synchronous lifting control principle: In addition to controlling the unified movement of all lifting cylinders, the main control computer must also ensure the synchronous position of each lifting point. In the lifting system, a master lifting point is set, and other lifting points are adjusted with reference to the position of the master lifting point, thus all following the lifting point.

[0165] The master lifting point determines the lifting speed of the entire lifting system. Operators can set the lifting speed based on the pump station's flow distribution and other factors. According to the existing lifting system design, the maximum lifting speed is no more than 10 meters per hour. The master lifting speed is set through a proportional valve in the proportional hydraulic system.

[0166] In the lifting system, a distance sensor is installed below each lifting point. During the lifting process, these sensors continuously measure the current height of the component and transmit this data to the main control computer via a real-time network. The tracking status of each following lifting point relative to the master lifting point can be reflected by the height difference measured by the distance sensors. Based on the current height difference between the following lifting points and the master lifting point, the main control computer uses a specific control algorithm to determine the control amount of the corresponding proportional valve, thereby achieving position synchronization between each following lifting point and the master lifting point.

[0167] To enhance component safety, hydraulic sensors are installed at each lifting point. The main control computer can monitor load changes at each lifting point in real time via the on-site network. If there is an abnormal sudden change in the load at a lifting point, the computer will automatically shut down and issue an alarm.

[0168] After determining the number of lifting cylinders, a position sensor is installed on each cylinder. These sensors reflect the position of the main cylinder and the tightness of the upper and lower anchors. Through a real-time network, the main control computer can acquire the current status of all lifting cylinders. Based on this status, the main control computer, considering the user's control requirements (e.g., manual, sequential control, automatic), determines the next action of each lifting cylinder. The computer control system sensor layout is as follows:

[0169] Pressure sensor: In a group of cylinders at each lifting point, select one cylinder to install a pressure sensor; the pressure sensor is installed on the large cavity side of the cylinder. Since the oil inlet pressure of all cylinders at the same lifting point is the same, the pressure of one cylinder represents the pressure of the same lifting point.

[0170] 2) Anchor and cylinder intelligent sensors: One anchor sensor is installed on the upper and lower anchor cylinders of each cylinder, and one cylinder position sensor is installed on the main cylinder.

[0171] 3) Connect each sensor to its respective communication module.

[0172] Connection to the on-site real-time network control system:

[0173] 1) Install a computer control cabinet on the ground, and run the proportional valve communication line, solenoid valve communication line, cylinder signal communication line and working power line from the computer control cabinet.

[0174] 2) Connect all pump stations to the network via the proportional valve communication line and the solenoid valve communication line.

[0175] 3) Connect all hydraulic cylinder signal communication modules to the network via the hydraulic cylinder signal communication line.

[0176] 4) Connect all the module power cords using the power cords.

[0177] 5) Once the sensor installation and connection to the field real-time network control system are completed, the setup of the computer control system is finished.

[0178] Depending on the different requirements of the lifting structure, the control system can implement different control modes: In this invention, based on the characteristics of the structure, two control modes will be prepared: a position synchronization control mode and a position synchronization and load distribution combined control mode, to control the synchronization of the grid roof and portal truss, and also to control the load distribution between relevant lifting points.

[0179] Advanced detection methods: This control system is equipped with a variety of advanced sensors to monitor the system status during the lifting process. At each lifting point, one 20-meter long-range sensor and one hydraulic pressure sensor are installed. Each lifting cylinder is equipped with one cylinder stroke sensor and two sets of anchor sensors. Sensor specifications and quantities are shown in the table below.

[0180]

[0181] Anchor status sensor: detects the anchor status of the lifting cylinder (anchor "loose" or anchor "tight") and transmits the anchor status signal to the main control computer via fieldbus.

[0182] Hydraulic pressure sensor: measures the working pressure of the lifting cylinder, reflecting the lifting or lowering of the load; the hydraulic pressure sensor used is imported from Germany, with a measurement accuracy of 0.5%.

[0183] Hydraulic cylinder stroke sensor: used to measure the stroke of the lifting cylinder in real time within the range of 0 to 250 mm, with a measurement error of 0.25 mm;

[0184] The main components of this sensor are imported from Japan: 20-meter long-distance sensor: used for real-time measurement of the spatial position of the lifting structure, with a measurement range of 20 meters and a measurement error of 0.25mm; the main components of this sensor are imported from Germany.

[0185] Alarm protection and display functions: The control software is equipped with functions such as load and position over-tolerance alarms and automatic shutdown to ensure the safety of the lifting operation; at the same time, important parameters such as load and position are displayed for easy operation and monitoring.

[0186] The embodiments described in this invention are for illustrative purposes only and do not constitute a limitation on the scope of the claims. Other substantially equivalent substitutions that can be conceived by those skilled in the art are all within the scope of protection of this invention.

Claims

1. A construction process for assembling a steel structure for a hangar, characterized in that, The specific steps involved in the assembly and construction of the hangar's steel structure are as follows: Step 1: Embedded parts installation, which includes the installation of embedded parts at the top of concrete frame columns, the installation of embedded bolts, and the installation of embedded parts for inter-column supports. Step 2: Install the inter-column bracing. The inter-column bracing is connected to the nodes on the concrete columns on both sides by bolts, and welded to the support ball in the middle. Since the inter-column bracing is too long, the inter-column bracing is connected by connecting plates. During installation, the middle connecting plate is first fixed with temporary supports, and then each inter-column bracing is hoisted separately. One side is temporarily connected to the node with ordinary bolts, and the other side is spot welded to the welding ball. After adjusting to the design elevation, the side connected with ordinary bolts is replaced with high-strength bolts, and the side that was spot welded is fully welded. Step 3: Space frame assembly construction. Assemble the space frame on the ground plane in the middle of the site. After the assembly jig is made, the space frame extends from the middle to both sides grid by grid. First the lower chord, then the upper chord, then the lower chord. The lower chord sphere must be on its projection line. Install the lower chord balls and poles of the first span to form a longitudinal planar grid, arrange the leveling support points to ensure the parallelism of the lower chord balls, and find the bottom of the slope at the temporary support points when the grid is arched; On the premise of ensuring the flatness of the ground for assembling the space frame, horizontal support points are set on the ground according to the relative elevation of the lower chord ball. The elevation of the horizontal support points is measured with a level to ensure that they are at the same elevation. After the elevation of the horizontal support points is determined, they should be marked accordingly. During this period, the support points should not be moved at will. In addition, the elevation of the support points should be checked with a level every day before construction to ensure that the elevation is accurate and to ensure the flatness of the lower chord ball. Step 4: The entire steel structure of the space frame is lifted. The space frame is lifted in two stages. The first stage is a 3-meter lift to install the lower truss of the gate. The second stage is a complete lift of the roof space frame. After the lift is completed, the members are installed and then unloaded one by one. The upper lifting support is set on the top of the original structural column, and the lower suspension point structure is a temporary support and a suspension point ball structure.

2. The hangar steel structure assembly construction process according to claim 1, characterized in that, In step 1, the method for embedding the pre-embedded parts at the top of the concrete frame column is as follows: First, the control line for the pre-embedded part position and the elevation line of the bottom plane should be measured and set. Before embedding the pre-embedded parts, each group of pre-embedded parts should be fixed to the pre-embedded plate and connected into a whole by a rigid frame. After the civil engineering unit has finished pouring the bottom plate, the bolt bracket should be in place before the steel reinforcement is tied at the pre-embedded bolt. The bracket should be positioned and supported firmly by a temporary reinforcement mechanism so that it matches the axis and elevation. The entire bracket should be embedded before the steel reinforcement is tied. After it is fixed, the civil engineering unit will tie it. The method for embedding the bolts is as follows: After the concrete of the column below the embedded part is poured, the embedded part can be inserted and initially checked. According to the axis of the survey, the embedded bolts are positioned as a whole. First, the longitudinal and transverse center lines of the four fixed angle steels on the upper part of the embedded part are found and made to match the reference line of the measurement and positioning. Then, the level is used to measure the top surface of the bolts at the four corners of the embedded part. If the height is insufficient, the bolts are leveled with steel bars or angle steel at the four corners of the four fixed angle steels below the embedded part. The method for embedding pre-supported parts between columns is as follows: the pre-embedded parts can be inserted during the construction of the concrete frame column reinforcement. During the embedding, close coordination with the civil engineering reinforcement and formwork sections is required. During the reinforcement construction, the pre-embedded iron can be fixed to the concrete wall reinforcement mesh. During the formwork construction, the verticality of the embedded plate can be accurately corrected. During the concrete construction process, it can be continuously adjusted to ensure the embedding accuracy of the pre-embedded parts.

3. The assembly and construction process for a hangar steel structure according to claim 1, characterized in that, In step 3, the space frame assembly platform is composed of an adjustable steel tire support. The cambering of the assembly is designed based on the maximum deflection value of the original space frame. The cambering value at each point of the lower chord sphere of the space frame is calculated based on the cambering value. The cambering of the space frame is achieved by adjusting the length of the positioning steel pipe under the space frame assembly support. The camber value of each point on the lower chord sphere of the space frame is different, so it is necessary to accurately measure the actual elevation of the assembly jig for each lower chord sphere to ensure the geometric dimensions of the space frame; the processing accuracy of the branch pipes requires the error to be controlled within ±1mm.

4. The assembly and construction process for a hangar steel structure according to claim 1, characterized in that, In step 3, the space frame assembly method is as follows: Step A, set up and level the frame support, install the lower chord ball on the top of the frame support, and connect the lower chord balls with the lower chord rod; Step B: The lower chord members form a unit with two rectangles. The web members and upper chord ball are installed in the first unit. The first cone is a small unit with one ball and four web members. After it is in place, it is connected and fixed to the lower chord ball. Step C: The second cone starts by installing a triangular cone with one ball, one chord, and two web members, and then filling in the other two web members, gradually cyclically installing the first unit of the space frame; Step D: Starting from the second unit of the space frame, the installation and assembly are carried out using a side-by-side method. Beginning from the side span, first install a triangular pyramid with one ball, one upper chord, and two web members, followed by a quadrangular pyramid with one ball, two upper chords, and two web members. Support the two diagonal web members on the lower chord ball, tighten the upper chord ball above, and gradually bring the upper chord ball closer to the installation position, filling in the upper chord members.

5. The assembly and construction process for a hangar steel structure according to claim 1, characterized in that, In step 3, the assembly of the hangar gate frame and hangar door node in the width direction of the frame is carried out by welding steel sections. The fixed end is connected to the steel balls on both sides by connecting plates at the welded ball nodes on both sides. The lower end of the steel section is opened with a round hole, which constitutes the upper hanging beam system of the whole door.

6. The assembly and construction process for a hangar steel structure according to claim 1, characterized in that, In step 4, the overall lifting steps of the space frame steel structure are designed as follows: (1) Lifting point arrangement: 12 lifting points are arranged during the first lifting of the roof space frame, and 10 lifting points are arranged for the second lifting; (2) Upper lifting frame arrangement: Since the concrete column section at the top of the steel column is relatively small, a corbel steel structure is set in the column top support structure; (3) Lifting lower suspension point arrangement: Lifting point balls are set at the position of the oil cylinder of the column top support, which serve as anchoring devices for the steel strands. Temporary support rods are used to connect the lifting point balls and other welded ball nodes of the space frame. The connected welded ball nodes are determined by calculation; (4) Temporary lifting support arrangement: Since the three-layer space frame above the gate has one more layer than the hall, the upper two layers of the space frame need to be assembled first and then lifted as a whole by 3m before assembling the remaining third layer of members. During the lifting, the space frame at the gate position only has two layers and does not form a whole. Because the deformation is relatively large during the lifting, two sets of temporary lifting points need to be added at the gate position. The lifting point support and the gate ground beam are connected with chemical anchor bolts.

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