Roof ceiling large flat plate installation method

Abstract

The invention relates to the technical field of building construction, in particular to a roof suspended ceiling large flat plate installation method which comprises the steps that S1, according to the plane size of a to-be-installed suspended ceiling and the arrangement position of a steel beam, the size and installation position of a suspended ceiling steel plate back stiffening plate and the block size and number of a suspended ceiling steel plate are designed and determined; s2, steel columns, main steel beams and secondary steel beams are sequentially installed according to the construction sequence, stiffening plates are welded and fixed to the main steel beams and the secondary steel beams, the stiffening plates comprise transverse stiffening plates and longitudinal stiffening plates, and a layered welding technology is adopted; after welding is completed, the overall levelness is remeasured and corrected; s3, the pre-numbered suspended ceiling steel plate is hoisted to the corresponding installation position, the suspended ceiling steel plate is attached to the stiffening plate and temporarily fixed through intermittent welding, and the depth of a welding seam is controlled to be 1 / 3 of the thickness of the steel plate; and S4, the suspended ceiling steel plates are welded and fixed one by one from one side of the suspended ceiling to the other side of the suspended ceiling according to a preset sequence, and deformation in the welding process is controlled.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building construction, in particular to a large flat plate installation method for roof suspended ceiling. BACKGROUND

[0002] In contemporary large public buildings, stadiums, transportation hubs and industrial plants, etc. large-span space structures, roof suspended ceiling system not only bears important decoration and space enclosing function, often also integrated lighting, fire, heating, ventilation and air conditioning (HVAC), sound and other equipment pipelines. Therefore, the design and construction of suspended ceiling system need to meet the multiple stringent requirements of structural safety, installation accuracy, functional integration and aesthetics, etc. Especially for large area more than 350 square meters of large flat plate suspended ceiling, its huge dead weight, the pursuit of extreme installation flatness and complex internal pipeline distribution, bring unprecedented technical challenges to the construction.

[0003] At present, the construction of this kind of large-span roof suspended ceiling transfer floor usually relies on traditional steel structure welding method or assembly type connection technology. The traditional welding method forms a rigid transfer floor by welding a large number of vertical rods, diagonal braces and transfer grids on the roof main steel beam. Although this method can provide strong structural support, its disadvantages are also very significant: first, the on-site welding operation has large engineering quantity, produces a large amount of smoke, arc light and noise, and has high requirements for construction environment and safety; second, the dense welding inevitably produces huge welding stress and thermal deformation in the steel structure, which makes it difficult to control the flatness of the transfer layer grid and even the final suspended ceiling plate, and a large amount of manpower and material resources need to be invested for correction in the later period; third, this method has poor flexibility, when large air pipes, water pipes or bridge need to pass through the inside of the suspended ceiling, the original transfer layer rod often needs to be cut off, which seriously damages the integrity and force transmission path of the structure, leaving safety hazards.

[0004] In order to reduce on-site welding, another assembly type connection structure is gradually applied, which pre-fabricates the connecting piece (such as hanging ear) on the steel beam in the factory, and then installs the transfer layer profile steel on site by bolts. Although this method improves the construction efficiency and reduces the damage to the fireproof coating to a certain extent, its inherent limitations are exposed in large-span, large-load projects: first, the bearing capacity and stiffness of its connection nodes (such as hanging ears, bolts) are limited, which is difficult to meet the requirements of large-span steel plate suspended ceiling in terms of dead weight and deformation, and is prone to looseness or deformation; second, the overall integrity of the structure system is poor, and lacks effective spatial stiffness, which is prone to sway under dynamic load (such as wind vibration, equipment vibration), affecting the stability and durability of the suspended ceiling; third, it lacks effective system-level solutions for the overall leveling of large-area suspended ceiling plate, and the final installation accuracy is difficult to guarantee.

[0005] In summary, the existing large-span roof suspended ceiling conversion layer technology, whether it is a traditional welding method or an assembled connection, is difficult to achieve an ideal balance between structural safety, installation precision, construction efficiency and economy. For super large plane steel plate suspended ceiling, developing a new installation method that can effectively control the structural deformation, ensure very high flatness, and can be constructed with various professional pipelines has become a key technical problem to be solved in the field. SUMMARY

[0006] In order to overcome the deficiencies of the prior art, the present application provides a large flat plate installation method for roof suspended ceiling, aiming to ensure the installation flatness of the suspended steel plate while improving the overall visual effect.

[0007] The technical means adopted by the present application to solve its technical problems is: a large flat plate installation method for roof suspended ceiling, wherein the improvement lies in that it comprises:

[0008] Step S1, according to the plane size of the suspended ceiling to be installed and the layout position of the steel beam, the size and installation position of the stiffener plate at the back of the suspended steel plate, and the block size and number of the suspended steel plate are determined;

[0009] Step S2, install the steel column, main steel beam and secondary steel beam in sequence according to the construction sequence, and weld and fix the stiffener plate on the main and secondary steel beams, wherein the stiffener plate comprises a transverse stiffener plate and a longitudinal stiffener plate, and a layered welding process is adopted; after welding, overall levelness is rechecked and corrected to ensure that the lower surface of the stiffener plate is flush with the lower flange surface of the steel beam;

[0010] Step S3, hoist the pre-numbered suspended steel plate to the corresponding installation position, make it fit with the stiffener plate and temporarily fix it by intermittent welding, and control the welding depth to be 1 / 3 of the thickness of the steel plate;

[0011] Step S4, weld and fix the suspended steel plate from one side to the other side in a predetermined sequence, and control the deformation in the welding process.

[0012] In the above technical solution, the installation of the stiffener plate in step S2 comprises: step S201, weld the transverse stiffener plate first, and recheck the levelness; step S202, spot weld the longitudinal stiffener plate, and recheck and correct the levelness after layered welding.

[0013] In the above technical solution, step S2 comprises:

[0014] According to the installation sequence, install the steel column, install the second layer main beam, install the second layer secondary beam, install the third layer main beam and the pull rod, install the third layer secondary beam, and install the stiffener plate of the large flat plate bottom plate.

[0015] In the steel column installation process, the automobile crane is used for hoisting, the theodolite is used for correction after hoisting in place, the column top elevation is adjusted to the design requirement, and the rated lifting capacity of the automobile crane is greater than the maximum installation weight after correction by the reduction coefficient.

[0016] In the two-layer steel beam installation process, the control points and lines on the steel column and the steel beam are used for corresponding control of the center line and the longitudinal distance, the measuring instrument is used for monitoring, the center line, the longitudinal distance and the elevation of the beam are adjusted, the steel beam and the steel column are fixed, the secondary beam is connected with the main beam through the connecting plate, and the screw and the welding are fastened after the axial position and the horizontal height are adjusted.

[0017] In the three-layer main beam pull rod and secondary beam installation process, the steel column is used for positioning the axial position and the horizontal height of the main beam and welding the positioning steel plate, the main beam is hoisted in place after the pull rod is arranged on the main beam, the horizontal degree is adjusted through the pull rod, the measuring instrument is used for monitoring the axial position to make the axial position coincide with the positioning line, the main beam is fixed on the steel column and the pull rod is fastened after the elevation is adjusted, and finally, the secondary beam is installed and the horizontal height is controlled.

[0018] In the large flat plate bottom plate stiffener installation process, the transverse stiffener is first welded on the steel beam, symmetrically layered welding is performed, the horizontal degree is re-measured to meet the requirement, the longitudinal stiffener is spot-welded and layered welded, the stiffener and the steel beam are connected into a whole, and the horizontal degree is re-measured and corrected to make the lower surface of the lower stiffener and the lower flange surface of the steel beam form a plane.

[0019] The step S3 comprises:

[0020] The lower layer block bottom plate is hoisted in place in sequence from one side to the other side, is spot-welded on the steel beam and the stiffener after leveling, the transverse stiffener and the bottom plate are segmented welded, the longitudinal stiffener and the bottom plate are segmented welded, and finally, the inter-plate weld is welded, and the inter-plate weld depth is controlled to be 1 / 3.

[0021] The step S4 comprises:

[0022] The upper layer block panel and the stiffener thereof are assembled and welded into a whole on the ground, are hoisted in place in sequence after it is ensured that the flatness of each small unit body meets the installation requirement, are spot-welded on the steel beam, the stiffener and the steel beam are welded first, and finally, the panel and the upper flange of the steel beam are welded, and the weld depth is controlled to be 1 / 3.

[0023] The present application has the following beneficial effects:

[0024] Through systematic process design, fine process control and multi-stage retest correction, the overall flatness and structural stability of large-scale suspended ceiling installation are effectively guaranteed. The process of hierarchical welding, sequential installation and modular pre-assembly is adopted, which significantly reduces the welding deformation, improves the installation precision and construction efficiency, and enhances the structural integrity, which is suitable for complex roof engineering with large span and high precision requirements. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A flowchart of a large flat plate installation method for a roof suspended ceiling is shown for the embodiment of the present application.

[0026] Figure 2 A flowchart of the installation of the stiffened plate is shown for the embodiment of the present application.

[0027] Figure 3 A flowchart of the installation of the steel beam and the stiffened plate is shown for the embodiment of the present application.

[0028] Figure 4 A schematic diagram of the installation of the steel beam and the stiffened plate is shown for the embodiment of the present application.

[0029] Figure 5 A panel structure diagram is shown for the embodiment of the present application. DETAILED DESCRIPTION

[0030] The present application will be further described below in conjunction with the drawings and embodiments.

[0031] The concept, specific structure and technical effects of the present application will be described clearly and completely in conjunction with the embodiments and drawings, so as to fully understand the purpose, features and effects of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. In addition, all the coupling / connection relationships involved in the patent do not mean that the components are directly connected, but that a better coupling structure can be composed by adding or reducing coupling accessories according to the specific implementation situation. The technical features in the present application can be combined interactively without conflict.

[0032] As shown in Figure 1 , the present application provides a large flat plate installation method for a roof suspended ceiling, which comprises:

[0033] Step S1, according to the plane size of the suspended ceiling to be installed and the layout position of the steel beam, the size and installation position of the stiffened plate at the back of the suspended steel plate, and the block size and number of the suspended steel plate are designed and determined.

[0034] Step S2, in the order of construction, the steel column, the main steel beam and the secondary steel beam are installed, and the stiffening plate is welded and fixed on the main and secondary steel beams, wherein the stiffening plate includes a transverse stiffening plate and a longitudinal stiffening plate, and a layered welding process is adopted; after welding, overall levelness is retested and corrected to ensure that the lower surface of the stiffening plate is flush with the lower flange surface of the steel beam.

[0035] Specifically, as shown in Figure 2 , the installation of the stiffening plate includes:

[0036] Step S201, first weld the transverse stiffening plate, and retest the levelness.

[0037] Step S202, then spot weld the longitudinal stiffening plate, layer-by-layer welding, and retest and correct the levelness after forming the whole.

[0038] In one possible implementation, as shown in Figure 3 , the steel column installation, two-layer main beam installation, two-layer secondary beam installation, three-layer main beam and pull rod installation, three-layer secondary beam installation, and large flat plate bottom stiffening plate installation are sequentially performed according to the installation order, and the specific schematic diagram is shown in Figure 4 .

[0039] In the steel column installation process, a truck crane is used for hoisting, and after hoisting in place, a theodolite is used for correction, the top elevation of the column is adjusted to the design requirement, and the rated lifting capacity of the truck crane is greater than the maximum installation weight after correction by the reduction coefficient.

[0040] Specifically, the heaviest single steel column is 514.5 kg, with a length of 4.4 m, and a 25-ton truck crane is used for hoisting, with an installation radius of about 12 m, a hoist arm height of 14 m, and an arm rod angle of 60°, so the arm length is: The maximum arm length is 20.85 m. When the steel beam is outside the working radius of the truck crane, the position of the truck crane is adjusted in time to ensure safety.

[0041] (1) Installation lifting weight

[0042] The maximum weight of the steel column is Q1 = 0.51T, and the maximum weight of the lock is Q2 = 0.25T, so the maximum weight during installation is Q = Q1 + Q2 = 0.51 + 0.25 = 0.76T.

[0043] (2) Selection of truck crane

[0044] A 25T truck crane is selected, with the legs fully extended, and according to the crane working condition table, in the working condition of operating radius 12m, arm 20.855m, the rated lifting capacity is 4.1T, i.e. 4.1T x 0.85 (reduction coefficient of crane) = 3.49 > 0.76T, proving that the truck crane hoisting working condition meets the requirements (25-ton truck crane performance table).

[0045] (3) Selection of wire rope: The standard shall be "General Purpose Wire Rope" (GB / T 20118-2006) and "Important Purpose Wire Rope" (GB / T 8918-2006).

[0046] The steel wire rope used in the hoisting process is selected according to the maximum weight of the component, and two hoisting points are set up for hoisting.

[0047] The tension in each wire rope is F = 0.76 ÷ 2 = 0.38T = 3.8KN.

[0048] Using 6×37+1 wire 1850Mpa grade steel wire rope with a diameter of Ф17.5mm for binding and lifting, the total breaking tensile force is F. g =156kN.

[0049] The allowable tensile force of the wire rope is:

[0050] It meets safety requirements.

[0051] (4) Shackle selection: Follow the standard "Forged Shackles for General Lifting" (JB-8112).

[0052] Given that the maximum force at a single lifting point is 3.8 kN, two "D" type rigging shackles with a safe load of 10 kN are selected. That is, 10 kN > 3.8 kN, which meets the requirements.

[0053] During the installation of the second-layer steel beams, the centerline and longitudinal distance are controlled by the corresponding control points and lines on the steel columns and steel beams. The centerline, longitudinal distance and beam elevation are monitored by measuring instruments. After the centerline, longitudinal distance and beam elevation are adjusted, the steel beams and steel columns are fixed. The secondary beams are connected to the main beams through connecting plates. After adjusting the axis position and horizontal height, the screws are tightened and welded.

[0054] During the installation of the three-layer main beam tie rods and secondary beams, the main beam axis position and horizontal height are located on the steel column and a positioning steel plate is welded. After the main beam with tie rods is hoisted into place, the horizontality is adjusted by the tie rods. The axis position is monitored by measuring instruments to make it coincide with the positioning line. After the elevation is adjusted, the main beam is fixed on the steel column and the tie rods are tightened. Finally, the secondary beams are installed and their horizontal height is controlled.

[0055] When installing the stiffening plates of the large flat plate base, the transverse stiffening plates are first leveled and spot-welded to the steel beams, and then welded symmetrically in layers. After the horizontality is re-measured and meets the requirements, the longitudinal stiffening plates are spot-welded and then welded in layers. After all the stiffening plates and steel beams are connected into a whole, the horizontality is re-measured and corrected again so that the lower surface of the lower stiffening plate is in a plane with the lower flange of the steel beam.

[0056] Specifically, first determine the thickness of the steel plate. Assuming the steel plate is a platform plate, the common thickness tp = 6-12mm, take tp = 12mm.

[0057] Next, the stiffening rib dimensions are initially selected. The rib height hs is generally 1 / 10 to 1 / 15 of the span.

[0058] Given hs = 1800 / 15 = 120mm, take 120mm.

[0059] The rib thickness ts is not less than the plate thickness tp, and it satisfies local stability (avoiding buckling):

[0060] ts≥max(tp,hs / 15)=max(12,120 / 15=8)→Take 16mm;

[0061] Next, the stiffening rib spacing aa is calculated. To prevent local instability of the steel plate and limit the deformation of the welding heat-affected zone, a≤30tp-60tp.

[0062] For tp = 12mm: a ≤ 30 × 12 = 360mm or 60 × 12 = 720mm; to balance economy and effectiveness, a = 500mm is chosen.

[0063] Finally, the stiffness ratio is checked. The ratio of the moment of inertia of the stiffener to that of the steel plate should satisfy: Is / Ip≥3 (empirical threshold).

[0064] Moment of inertia per unit width of steel plate: Ip=(1×tp) 3 ) / 12=12 3 / 12=144mm 3 ;

[0065] Moment of inertia of a single stiffening rib: Is = (ts x hs) 3 / 12=(16×120) 3 / 12=2.3×10 6 mm 4 ;

[0066] Equivalent unit wide moment of inertia (allocated over a spacing a = 500): I s,eq =Is / a=2.310 6 / 500=4676mm 3 Stiffness ratio: I s,eq / Ip=2880 / 144=32>3 (Requirement met)

[0067] Step S3: Hoist the pre-numbered ceiling steel plate to the corresponding installation position, attach it to the stiffening plate and temporarily fix it with intermittent welding, and control the weld depth to 1 / 3 of the steel plate thickness.

[0068] Specifically, the lower-level segmented base plates are hoisted and positioned sequentially from one side to the other. After leveling, they are spot-welded to the steel beams and stiffening plates. First, the welds between the transverse stiffening plates and the base plates are welded in sections, then the welds between the longitudinal stiffening plates and the base plates are welded in sections, and finally the welds between the base plates are welded, with the depth of the welds between the plates controlled to 1 / 3.

[0069] In order to achieve a better flatness effect, since the weld between the plates only serves as an aesthetic function of sealing the surface layer and does not serve as a load-bearing support for the steel plate, in order to reduce the impact of the weld on the deformation of the base plate, the weld between the plates is only welded to about 3mm at 1 / 3 of the weld.

[0070] Step S4: Weld and fix the ceiling steel plates one by one from one side of the ceiling to the other in a predetermined order, and control the deformation during the welding process.

[0071] Specifically, during the installation of the large flat panel, the upper-layer segmented panels and their stiffening plates are assembled and welded together on the ground. After ensuring that the flatness of each small unit meets the installation requirements, they are hoisted into place in sequence and spot-welded to the steel beam. First, the weld between the stiffening plate and the steel beam is added, and finally the weld between the panel and the upper flange of the steel beam is applied, with the weld depth controlled to 1 / 3.

[0072] Among them, such as Figure 5 As shown, the large flat plate consists of two identical layers. The bottom plate measures 30700*12150mm and is divided into 42 sections, with the largest section area being 6350*2000mm and a weight of 797.56kg. The top plate consists of 56 sections, with the largest section area being 4450*1850mm and a weight of 517kg. The upper and lower stiffening plates are mesh-like, with a mesh size of 500*500mm and a stiffening plate size of PL90*16mm, extending continuously and connecting to the steel beams.

[0073] In addition, by analyzing the possible causes of steel plate deformation in steel structure welding processes, the welding process was optimized. ① CO2 gas shielded welding uses thin welding wire, has a high current density, concentrates heating, and results in minimal deformation. 0.8mm welding wire should be selected for CO2 gas shielded welding. ② The higher the heat input, the greater the welding deformation. Welding deformation increases with increasing welding current and arc voltage, and decreases with increasing welding speed. Adjust welding parameters, using lower voltage and current as much as possible, and increasing welding speed. ③ Continuous welding and intermittent welding produce different temperature fields, resulting in different thermal deformations. Choose the smallest possible weld leg size and shortest weld bead. Symmetrical welding is more effective in reducing welding deformation. The welding method should be segmented back-welding, welding from the middle outwards, generally in 100mm segments. After the transverse weld is completed, use a hammering method (using a small round-headed hammer to tap the weld) to extend it appropriately, compensating for the shrinkage during welding and reducing welding shrinkage. Then, the longitudinal spot welds are ground off to restore the steel plate to its original structural form as much as possible, and then the longitudinal welds are applied.

[0074] Through the above embodiments, this application employs a systematic process design, meticulous process control, and multi-stage retesting and correction to effectively ensure the overall flatness and structural stability of large-scale ceiling installations. It utilizes layered welding, intermittent welding, sequential installation, and modular pre-assembly processes, significantly reducing welding deformation, improving installation accuracy and construction efficiency, while enhancing structural integrity. This makes it suitable for complex roofing projects with large spans and high precision requirements.

[0075] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for installing a large flat panel for roof ceiling, characterized in that, The method includes: Step S1: Based on the planar dimensions of the ceiling to be installed and the layout of the steel beams, design and determine the dimensions and installation position of the stiffening plate on the back of the ceiling steel plate, as well as the segment dimensions and numbering of the ceiling steel plate. Step S2: Install the steel columns, main steel beams and secondary steel beams in sequence according to the construction order, and weld the stiffening plates to the main and secondary steel beams. The stiffening plates include transverse stiffening plates and longitudinal stiffening plates, and adopt a layered welding process. After welding, the overall levelness is re-measured and corrected to ensure that the lower surface of the stiffening plate is flush with the lower flange surface of the steel beam. Step S3: Hoist the pre-numbered ceiling steel plate to the corresponding installation position, attach it to the stiffening plate and temporarily fix it with intermittent welding, and control the weld depth to 1 / 3 of the steel plate thickness; Step S4: Weld and fix the ceiling steel plates one by one from one side of the ceiling to the other in a predetermined order, and control the deformation during the welding process.

2. The method for installing a large flat panel for roof ceiling according to claim 1, characterized in that, The installation of the stiffening plate in step S2 includes: Step S201: First, weld the transverse stiffening plate and then re-measure the levelness; Step S202: Spot weld the longitudinal stiffening plates, perform layered welding, and after forming the whole, re-measure and correct the levelness.

3. The method for installing a large flat panel for roof ceiling according to claim 1, characterized in that, Step S2 includes: The installation sequence is as follows: steel column installation, second-floor main beam installation, second-level beam installation, third-floor main beam and tie rod installation, third-level beam installation, and large flat plate base plate stiffening plate installation.

4. The method for installing a large flat panel for roof ceiling according to claim 3, characterized in that, During the installation of the steel columns, a truck crane is used for hoisting. After the columns are hoisted into place, a theodolite is used for correction, and the elevation of the column top is adjusted to meet the design requirements. The rated lifting capacity of the truck crane, after being corrected by a reduction factor, is greater than the maximum installation weight.

5. The method for installing a large flat panel for roof ceiling according to claim 3, characterized in that, During the installation of the second-layer steel beams, the centerline and longitudinal distance are controlled by the corresponding control points and lines on the steel columns and steel beams. The centerline, longitudinal distance and beam elevation are monitored by measuring instruments. After the centerline, longitudinal distance and beam elevation are adjusted, the steel beams and steel columns are fixed. The secondary beams are connected to the main beams through connecting plates. After adjusting the axis position and horizontal height, the screws are tightened and welded.

6. The method for installing a large flat panel for roof ceiling according to claim 3, characterized in that, During the installation of the three-layer main beam tie rods and secondary beams, the main beam axis position and horizontal height are located on the steel column and positioning steel plates are welded. After the main beam with tie rods is hoisted into place, the horizontality is adjusted by the tie rods. The axis position is monitored by measuring instruments to make it coincide with the positioning line. After adjusting the elevation, the main beam is fixed on the steel column and the tie rods are tightened. Finally, the secondary beams are installed and their horizontal height is controlled.

7. The method for installing a large flat panel for roof ceiling according to claim 3, characterized in that, When installing the stiffening plates of the large flat plate base, first level and spot weld the transverse stiffening plates onto the steel beam, then weld them symmetrically in layers. After re-measuring the levelness and ensuring it meets the requirements, spot weld the longitudinal stiffening plates and weld them in layers. After connecting all the stiffening plates and the steel beam into a whole, re-measuring the levelness and correcting it so that the lower surface of the lower stiffening plate is in a plane with the lower flange of the steel beam.

8. The method for installing a large flat panel for roof ceiling according to claim 1, characterized in that, Step S3 includes: The lower-level segmented base plates are hoisted and positioned sequentially from one side to the other. After leveling, they are spot-welded to the steel beams and stiffening plates. First, the welds between the transverse stiffening plates and the base plates are welded in sections. Then, the welds between the longitudinal stiffening plates and the base plates are welded in sections. Finally, the welds between the base plates are welded, and the depth of the welds between the plates is controlled to 1 / 3.

9. The method for installing a large flat panel for roof ceiling according to claim 1, characterized in that, Step S4 includes: On the ground, the upper-layer panel and its stiffening plate are assembled and welded into a whole. After ensuring that the flatness of each small unit meets the installation requirements, they are hoisted into place in sequence and spot-welded to the steel beam. First, the weld between the stiffening plate and the steel beam is added, and finally the weld between the panel and the upper flange of the steel beam is applied, with the weld depth controlled to 1 / 3.

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