Construction method of large-span elliptical steel structure roof

Abstract

The application discloses a large-span elliptic steel structure roof construction method, and belongs to the technical field of steel structure construction, and comprises the following steps: S1, truss layer structure division, the truss layer is a net rack structure composed of main trusses, connecting trusses and cantilever trusses; S2, construction hoisting support structure, the hoisting support structure comprises outer enclosure structure columns, inner support structure columns and temporary inner support frames; S3, ground assembling and hoisting unit, the main trusses are horizontally assembled on a ground bed frame, and the main purlines at corresponding positions are simultaneously preassembled to form a hoisting unit; S4, hoisting units are hoisted and connected trusses and cantilever trusses are installed in steps, the hoisting units are installed according to the sequence from the long axis of the ellipse to the short axis of the ellipse; S5, main purline adjustment and installation; and S6, secondary purline installation. According to the characteristics of complex stress and variable roof curvature of the large-span elliptic steel structure, the ground main purline is simultaneously preassembled to reduce high-altitude welding operation, the large-span construction difficulty is solved, and the construction efficiency and structural precision are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of steel structure construction, and in particular to a construction method for a large-span elliptical steel structure roof. Background Technology

[0002] Contemporary large-scale public buildings are increasingly characterized by large spans and irregular shapes, with stadiums being particularly prevalent in their use of irregularly shaped, large-span steel structures. Among these, elliptical steel space frames have become the mainstream choice due to their high space utilization and aesthetically pleasing appearance. However, such structures typically feature large spans, complex shapes, and a wide variety of components, placing extremely high demands on construction techniques and structural support solutions.

[0003] Currently, high-altitude assembly is commonly used in such projects. This method requires the installation of the main purlin supports and purlins after the main structure is completed. Due to the large number of main purlin supports and purlins in these projects, there is a significant amount of high-altitude assembly and welding work on site. Workers at height need to repeatedly go up and down, which not only results in low construction efficiency but also significantly increases safety hazards such as falls and ignition from welding sparks, placing immense pressure on construction safety management.

[0004] Therefore, the problem to be solved by this invention is how to design a construction method for a large-span elliptical steel space frame that is low in cost, easy to install, and has excellent structural stability. Summary of the Invention

[0005] This invention provides a construction method for a large-span elliptical steel structure roof, which solves the technical problems in the background art such as large amount of high-altitude work, high construction safety risks, and difficulty in temporary support of the central ring truss for large-span elliptical steel structures.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A construction method for a large-span elliptical steel structure roof, wherein the steel structure roof comprises, from bottom to top, a truss layer, a main purlin layer, a secondary purlin layer, and a roof layer, comprising the following steps: S1, Truss layer structure division, the truss layer is an elliptical grid structure composed of main trusses, connecting trusses and cantilever trusses, the main trusses include a central ring truss located at the center of the roof and structural radial trusses distributed radially; S2, Construction hoisting support structure, the hoisting support structure includes an outer protective structure column, an inner support structure column and a temporary inner support frame, the temporary inner support frame is located directly below the central annular truss, the inner support structure column is arranged in two rows, its overall distribution is parallel to the minor axis of the ellipse and symmetrical about the minor axis of the ellipse; S3, Ground assembly and hoisting unit, the main truss is horizontally assembled on the ground frame, and the main purlins at the corresponding positions are pre-installed simultaneously to form a hoisting unit. The main purlins are fixed to the main truss through the main purlin connectors and are distributed radially along the roof. S4, hoist the hoisting unit in stages and install the connecting truss and cantilever truss: S41, using the temporary inner support frame as the installation base point, the hoisting unit containing the central annular truss is hoisted in two parts; S42, the hoisting unit containing the two radial trusses located at the major axis of the ellipse; S43, hoisting the hoisting unit adjacent to the already installed hoisting unit; S44, After the adjacent radial trusses are installed in place, install the connecting truss between them and the cantilever truss at the end; S45, repeat steps S43 and S44 in the hoisting sequence radiating from the major axis to the minor axis of the ellipse until all hoisting units are in place; S5, Main purlin adjustment and installation: After the hoisting unit is installed in place, the elevation of the main purlin is re-measured and adjusted, and the main purlin is installed with the connecting truss and cantilever truss as the installation base points; S6, Secondary purlin installation: After the truss layer and main purlin layer are installed and unloaded and stabilized, the secondary purlins are installed. The secondary purlins are fixed to the main purlins by secondary purlin connectors and are distributed circumferentially along the roof. S7, install gutter joists and eaves joists; S8, a combination of roof slab and waterproof and thermal insulation layer; S9, Install the roof support layer and roof panels; S10, install gutter boards and eaves panels.

[0007] Furthermore, the temporary internal support frame is composed of several evenly arranged unit support frames, each unit support frame including a lattice tower column, a working platform set at the top of the lattice tower column, and a ladder installed on one side of the lattice tower column. The bottom of the lattice-type tower column is fixed to the embedded parts of the concrete foundation; A tie beam connects the tops of adjacent lattice-type tower columns; The top surface of the work platform is provided with a negative pressure plate, and the central annular truss is fixed to the temporary inner support frame through the negative pressure plate; Several sets of guy ropes are spaced apart along the height direction on the lattice-type tower column. The other end of the guy ropes extends away from the center of the roof and is fixed to the foundation structure.

[0008] Furthermore, in step S4, the top of the hoisting unit containing the radial truss of the structure is fixed to the central annular truss, and the bottom is fixed to the outer protective structure column; When the pre-set installation node of the hoisting unit near the major axis of the ellipse corresponds to the position of the inner support structure column along its length, the hoisting unit is fixed to the top of the inner support structure column through the pre-set installation node.

[0009] Furthermore, the structural radial truss is fixed to the outer enclosure structural columns and the inner support structural columns by seismic spherical hinge supports; the top of the outer enclosure structural columns and the inner support structural columns are provided with embedded plates, and the base of the seismic spherical hinge supports is fixed to the embedded plates.

[0010] Furthermore, the main purlin connector includes a fixing seat connected to the truss layer, a main purlin bracket connected to the fixing seat, and a main purlin ear plate connecting the main purlin bracket and the main purlin; the secondary purlin connector includes a secondary purlin bracket connected to the main purlin, and a secondary purlin ear plate connecting the secondary purlin bracket and the secondary purlin; both the main purlin ear plate and the secondary purlin ear plate are square plate structures, and each plate surface is provided with several connecting holes; the connecting holes on the main purlin ear plate fixed to the higher end of the main purlin are round holes, and the connecting holes on the main purlin ear plate fixed to the lower end of the main purlin are transversely elongated holes; the connecting holes on the secondary purlin ear plate are transversely elongated holes.

[0011] Furthermore, it also includes step S0, verification and adjustment: using finite element analysis software to perform a full-process simulation verification of the overall steel structure; in the full-process simulation verification, stress and deformation monitoring are performed on the key stress-bearing parts of the steel structure roof, and the arrangement scheme of the internal support structure columns and the temporary internal support frame is optimized by analyzing the load combinations of different construction stages.

[0012] Furthermore, the steel structure roof is provided with a gutter assembly and an eaves assembly in sequence at the end. The gutter assembly includes a U-shaped gutter keel and a gutter plate, and the eaves assembly includes an eaves keel and an eaves panel. In step S7, the U-shaped gutter keel is assembled into several assembly units on the ground, and then the units are hoisted and fixed to the end of the main purlin layer and spliced. The eaves keel extends along the outside of the cantilever truss, with one end fixed to the outside of the U-shaped gutter keel and the other end fixed to the vertical bar at the end of the main truss.

[0013] Furthermore, the waterproof and thermal insulation composite layer is composed of a vapor barrier membrane, non-woven fabric, sound-absorbing cotton, waterproof layer support components, waterproof roll material, and thermal insulation rock wool arranged sequentially from bottom to top; Step S8 specifically includes the following steps: S81, Install the roof base plate. The roof base plate is constructed by overlapping it sequentially from high to low along the slope. The overlap is located at the bottom end of the secondary purlin, and the overlap length is not less than 100mm. The roof base plate is fixed to the bottom end of the secondary purlin by connectors. S82, Install vapor barrier membrane, non-woven fabric and sound-absorbing cotton, the vapor barrier membrane, non-woven fabric and sound-absorbing cotton are laid sequentially between adjacent secondary purlins, and the sound-absorbing cotton fills the gap between adjacent secondary purlins; S83, Install a waterproof layer support assembly, the waterproof layer support assembly includes a support angle steel fixed on the secondary purlin and a support mesh laid on the secondary purlin and the support angle steel, the support angle steel is fixed to the upper edge of the secondary purlin by a connector and the top end is flush with the top end, the support mesh is laid on the upper part of the support angle steel and the secondary purlin and fixed by a fastener; S84, Install waterproof membrane and thermal insulation rock wool. Lay the waterproof membrane on the support net along the radial direction of the roof, with an overlap length of not less than 100mm. Lay the thermal insulation rock wool on the waterproof membrane.

[0014] Furthermore, the steel structure roof is divided into a high curvature section, a variable curvature section, and a low curvature section from the center of the roof along the radial direction of the roof according to the curvature of the roof; The roof panels in the high curvature section are made of metal veneer, which is laid on the roof support layer composed of supporting keel; The roof panel of the variable curvature section adopts a fan-shaped roof panel, which is laid on a roof support layer composed of support components, including supports and brackets; The roof panels in the low curvature section are fan-shaped roof panels, which are laid on the roof support layer composed of supports; Step S9 specifically includes the following steps: S91, Install the roof support layer. In the high curvature section, fix the support keel to the top of the secondary purlin connector through the connector. The support keel is distributed radially along the roof. In the variable curvature section, determine the arrangement position of the support components according to the fan-shaped roof panel layout drawing, fix the bracket to the secondary purlin, and fix the support to the bracket. In the low curvature section, determine the arrangement position of the support according to the fan-shaped roof panel layout drawing, and fix the support directly to the secondary purlin. S92, Install the roof panel. In the high curvature section, lay the metal panel on the supporting keel through the connector. In the variable curvature section and low curvature section, according to the position of the support, hoist the fan-shaped roof panel to the roof and adjust its position. Use the method of first manually locking the edges and then electrically locking the edges to interlock and fix the fan-shaped roof panel on the support. Among them, the roof panels at the joints between the high curvature section and the variable curvature section, and between the variable curvature section and the low curvature section, adopt the slope overlap.

[0015] Furthermore, in step S10, the prefabricated gutter slab is hoisted to the inside of the U-shaped gutter keel for assembly. The gutter slab is pressed and fixed by gutter pressure blocks on both sides, and a gutter expansion joint is set at intervals. The eaves panel is laid tightly against the outside of the eaves keel through connectors.

[0016] The beneficial effects of this invention are reflected in: (1) The present invention adopts the scheme of hoisting the main truss and the main purlin as a whole, which solves the problem of large amount of high-altitude work and low efficiency. By assembling the main purlin and the unit truss into a hoisting unit on the ground, the modular installation of the steel structure is realized, which reduces the number of times the main purlin is hoisted in pieces by about 50%, significantly reduces the cost of machinery rental and labor costs, and greatly improves the construction efficiency. (2) The present invention solves the problem of difficult control of installation accuracy of irregular structure by adopting adjustable purlin connecting components. It adopts purlin ear plate with horizontal elongated hole to provide length tolerance for purlin installation. Considering that the main purlin has an inclined angle, the upper end is equipped with a round hole to avoid later slippage, thus taking into account both installation convenience and stability. (3) The present invention adopts a multi-support scheme. For the elliptical structure, the truss span in the long axis region is large. The present invention adds an internal support structure column in this region, which, together with the external protective structure column and temporary internal support frame of the structure itself, constructs a stable truss hoisting base. The support scheme of two-point support and three-point support is adopted to achieve a balanced distribution of structural forces during construction and structural stability of the large span roof after construction. (4) The present invention uses a segmented structure of roof panels and roof support layers to match the curvature changes of elliptical roofs, and improves the windproof, water-guiding and waterproof structures at the upper and lower ends of each section, thereby comprehensively improving the waterproof, seepage-proof and wind-resistant durability of the roof.

[0017] This application thus solves the technical problems of large-span elliptical steel structures, such as the large amount of high-altitude work, high construction safety risks, and difficulties in temporary support of the central ring truss. Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention; the main objectives and other advantages of the invention may be realized and obtained by means of the methods particularly pointed out in the description. Attached Figure Description

[0018] Figure 1 This is a flowchart of the construction method according to an embodiment of the present invention; Figure 2 This is a schematic cross-sectional view of the building structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the installation of the central annular truss and the structural radial truss located on the major axis of the ellipse in an embodiment of the present invention; Figure 4This is a schematic diagram of the installation sequence of the radial truss structure according to an embodiment of the present invention. Figure 5 This is a schematic diagram of the truss layer installation completed according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the temporary internal support frame structure according to an embodiment of the present invention. Figure 7 This is a structural schematic diagram of the main purlin connector according to an embodiment of the present invention. Figure 8 This is a schematic diagram of the structure of the secondary purlin connector according to an embodiment of the present invention. Figure 9 This is a schematic diagram of the roof base plate and waterproof and thermal insulation composite layer structure according to an embodiment of the present invention. Figure 10 This is a schematic diagram of the gutter assembly and eaves assembly structure according to an embodiment of the present invention. Figure 11 This is a schematic diagram of the high curvature section roof structure according to an embodiment of the present invention. Figure 12 This is a schematic diagram of the variable curvature section roof structure according to an embodiment of the present invention. Figure 13 This is a schematic diagram of the low curvature section roof structure according to an embodiment of the present invention. Figure 14 This is a schematic diagram of the overlap between the high curvature section and the variable curvature section of the roof in an embodiment of the present invention. Figure 15 This is a schematic diagram of the overlap between the variable curvature section and the low curvature section of the roof in an embodiment of the present invention. Figure 16 This is a schematic diagram of the installation nodes of the radial truss and internal support column in an embodiment of the present invention. Figure 17 This is a schematic diagram of the installation nodes of the radial truss and the outer enclosure column in an embodiment of the present invention. Figure 18 This is a schematic diagram of the waterproof layer support component structure according to an embodiment of the present invention. Reference numerals: 1-External envelope column, 2-Internal support column, 3-Temporary internal support frame, 31-Unit support frame, 311-Lattice tower column, 312-Working platform, 313-Ladder, 32-Tie beam, 33-Guide rope, 4-Main truss, 41-Central ring truss, 42-Structural radial truss, 5-Connecting truss, 6-Cantilever truss, 7-Main purlin, 8-Secondary purlin, 9-Main purlin connector, 91-Fixed seat, 92-Main purlin bracket, 93-Main purlin ear plate, 10-Secondary purlin connector, 101-Secondary purlin bracket, 102-Secondary purlin ear plate, 11-Gutter assembly, 111-U-shaped gutter keel, 112-Gutter 12-Eaves assembly, 121-Eaves keel, 122-Eaves panel, 13-Roof base plate, 14-Waterproof and thermal insulation composite layer, 141-Vacuum barrier membrane, 142-Non-woven fabric, 143-Sound absorbing cotton, 144-Waterproof layer support assembly, 144a-Support angle steel, 144b-Support mesh, 145-Waterproof membrane, 146-Insulation rock wool, 15-Support keel, 16-Bearing, 161-Locking clip, 17-Z-shaped bracket, 18-Metal veneer, 19-Fan-shaped roof panel, 20-Seismic ball hinge bearing, 21-Embedded plate, 22-Clamping hoop, 23-Slope board, 24-Foam plug, 25-Windproof bearing, 251-Factor. Detailed Implementation

[0019] The technical solutions of the present invention will be described in detail below through embodiments. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solutions of the present invention, and should not be construed as limiting the technical solutions of the present invention. Example

[0020] An elliptical, large-span steel truss stadium, its cross-section as follows: Figure 2 As shown, the total building area is 8070㎡, and the total steel consumption of the steel structure is approximately 327 tons. The structural plan is elliptical, with an overall length of 84.47m in the east-west direction and 69.49m in the north-south direction. It adopts a radially arranged planar truss structure system, with a total of 26 main steel trusses, 8 connecting trusses from the central ring to the edge trusses on the outer side of the structure, and 30 cantilever trusses on the outer side. The component cross-sections use straight-seam steel pipes. The following technical solutions were adopted for the construction of its steel structure: A construction method for a large-span elliptical steel structure roof, wherein the steel structure roof, from bottom to top, comprises a truss layer, a main purlin layer, a secondary purlin layer, and a roof layer, as follows: Figure 1 As shown, it includes the following steps: S1, truss layer structure division. The truss layer is an elliptical space frame structure composed of main truss 4, connecting truss 5 and cantilever truss 6. The main truss 4 includes a central ring truss 41 located at the center of the roof and radial structural trusses 42 distributed in a radial pattern.

[0021] S2, construction hoisting support structure, the hoisting support structure includes outer protective structure column 1, inner support structure column 2 and temporary inner support frame 3. The temporary inner support frame 3 is located directly below the central ring truss 41. The inner support structure column 2 is arranged in two rows, and its overall distribution is parallel to the minor axis of the ellipse and symmetrical about the minor axis of the ellipse.

[0022] S3, ground assembly and hoisting unit, the main truss 4 is horizontally assembled on the ground frame, and the main purlins 7 at the corresponding positions are pre-installed to form a hoisting unit. The main purlins 7 are fixed to the main truss 4 through the main purlin connectors 9, and they are distributed radially along the roof.

[0023] S4, install the hoisting unit in stages and install the connecting truss 5 and cantilever truss 6: S41, as Figure 3 As shown, the hoisting unit containing the central annular truss 41 is hoisted in two parts with the temporary inner support frame 3 as the installation base point. The central annular truss 41 is divided into two parts with the major axis of the ellipse as the dividing line. S42, the hoisting unit containing the two radial trusses 42 located at the major axis of the ellipse; S43, as Figure 4 As shown, the hoisting unit is adjacent to the already installed hoisting unit, that is, the installation sequence is to prioritize the hoisting unit where the longer-span structural radial truss 42 is located; S44, after the adjacent radial truss 42 is installed in place, the connecting truss 5 between the two and the cantilever truss 6 at the end are installed. The top of the cantilever truss 6 is fixed to the end of the main truss 4 with its top aligned, and its height is about half that of the main truss 4. S45, repeat steps S43 and S44 in the hoisting sequence radiating from the major axis to the minor axis of the ellipse until all hoisting units are in place. The completed installation state is as follows: Figure 5 As shown.

[0024] S5, Main purlin adjustment and installation: After the hoisting unit is installed in place, the elevation of the main purlin 7 is re-measured and adjusted. The elevation of the main purlin 7 is detected and re-measured using a total station. The main purlin 7 is installed with the connecting truss 5 and the cantilever truss 6 as the installation base points. The main purlin 7, which was pre-installed and fixed on the structural radial truss 42 in step S3, is partially installed on the connecting truss 5 and the cantilever truss 6 to shape the roof.

[0025] S6. After the truss layer and main purlin layer are installed and unloaded and stabilized, the secondary purlin 8 is installed. The secondary purlin 8 is fixed to the main purlin 7 by the secondary purlin connector 10 and is distributed along the circumference of the roof.

[0026] S7, install gutter joists and eaves joists.

[0027] S8, paved roof base 13 and waterproof and thermal insulation composite layer 14.

[0028] S9, Install the roof support layer and roof panels.

[0029] S10, install gutter board 112 and eaves panel 122.

[0030] The temporary internal support frame 3 is composed of several uniformly arranged unit support frames 31. In this embodiment, the positions of the unit support frames 31 correspond to the endpoints of the long axis and short axis of the central annular truss 41, respectively. The central annular truss 41 is temporarily fixed by four-point support. The unit support frame 31 includes a lattice tower column 311, a working platform 312 set at the top of the lattice tower column 311, and a ladder 313 installed on one side of the lattice tower column 311. The bottom of the lattice-type tower column 311 is fixed to the embedded parts of the concrete foundation; A tie beam 32 connects the tops of adjacent lattice tower columns 311; The top surface of the work platform 312 is equipped with a negative pressure plate, and the central ring truss 41 is fixed to the temporary inner support frame 3 through the negative pressure plate; Several sets of guy ropes 33 are spaced along the height direction on the lattice tower column 311. The other end of the guy ropes 33 extends away from the center of the roof and is fixed to the foundation structure.

[0031] In step S4: the top of the hoisting unit where the structural radial truss 42 is located is fixed on the central annular truss 41 and the bottom is fixed on the outer protective structure column 1; when the preset installation node of the hoisting unit near the major axis of the ellipse corresponds to the position of the inner support structure column 2 along the length direction, the hoisting unit is fixed to the top of the inner support structure column 2 through the preset installation node.

[0032] like Figure 16 and Figure 17 As shown, the structural radial truss 42 is fixed to the outer enclosure column 1 and the inner support column 2 by the seismic ball hinge support 20; the top of the outer enclosure column 1 and the inner support column 2 is provided with a pre-embedded plate 21, and the base of the seismic ball hinge support 20 is fixed on the pre-embedded plate 21.

[0033] like Figure 7 As shown, the main purlin connector 9 includes a fixing seat 91 connected to the truss layer, a main purlin bracket 92 connected to the fixing seat 91, and a main purlin ear plate 93 connecting the main purlin bracket 92 and the main purlin 7; as Figure 8As shown, the secondary purlin connector 10 includes a secondary purlin bracket 101 connected to the main purlin 7, and a secondary purlin ear plate 102 connecting the secondary purlin bracket 101 and the secondary purlin 8; both the main purlin ear plate 93 and the secondary purlin ear plate 102 are square plate structures, and several connecting holes are opened on their surfaces; the connecting holes on the main purlin ear plate 93 fixed at the higher end of the main purlin 7 are round holes, and the connecting holes on the main purlin ear plate 93 fixed at the lower end of the main purlin 7 are transverse elongated holes; the connecting holes on the secondary purlin ear plate 102 are transverse elongated holes.

[0034] During the pre-installation of the main purlin 7 on the ground in step S3, the main purlin ear plate 93 and the main purlin support 92 are temporarily connected and fixed by spot welding. In step S5, if the elevation of the main purlin 7 is qualified after re-measurement, the spot welded parts are fully welded and fixed. If the elevation of the main purlin 7 is not qualified after re-measurement, the elevation of the main purlin 7 can be corrected by adjusting the height of the main purlin ear plate 93.

[0035] The process also includes step S0, verification and adjustment: using finite element analysis software to perform a full-process simulation verification of the overall steel structure construction; in the full-process simulation verification, stress and deformation monitoring are performed on the key stress-bearing parts of the steel structure roof, and the arrangement scheme of the internal support structure columns 2 and temporary internal support frames 3 is optimized by analyzing the load combinations at different construction stages; in this embodiment, based on the finite element simulation verification in the previous step S0, the temporary internal support frame 3 adopts four unit support frames 31, and the internal support structure columns 2 are arranged in two rows with a total of six, as follows. Figure 4 As shown, the spacing is uniform, supporting the hoisting unit located on the major axis of the ellipse and the hoisting unit spaced one structural radial truss 42 near the major axis. The six structural radial trusses 42 near the major axis of the ellipse are supported at three points, while the remaining structural radial trusses 42 are supported at two points, ensuring the stability of the large-span elliptical structure while avoiding excessive support.

[0036] During the hoisting process from steps S4 to S6, a total station is used to dynamically monitor the entire hoisting operation and strictly control the installation accuracy.

[0037] like Figure 10 As shown, gutter assembly 11 and eaves assembly 12 are sequentially installed at the end of the steel structure roof. Gutter assembly 11 includes U-shaped gutter keel 111 and gutter plate 112. Eaves assembly 12 includes eaves keel 121 and eaves panel 122. In step S7, U-shaped gutter keel 111 is assembled into several assembly units on the ground, and then the units are hoisted and fixed to the end of the main purlin layer and spliced. Eaves keel 121 extends along the outside of the cantilever truss 6, with one end fixed to the outside of U-shaped gutter keel 111 and the other end fixed to the vertical bar at the end of the main truss 4.

[0038] like Figure 9As shown, in step S8, the waterproof and thermal insulation composite layer 14 is composed of a vapor barrier membrane 141, a non-woven fabric 142, a sound-absorbing cotton 143, a waterproof layer support assembly 144, a waterproof roll 145, and thermal insulation rock wool 146 arranged sequentially from bottom to top. Step S8 specifically includes the following steps: S81, Install the roof base plate 13. The roof base plate 13 is constructed by overlapping it from high to low along the slope. The overlap is located at the bottom of the secondary purlin 8, and the overlap length is not less than 100mm. The roof base plate 13 is fixed to the bottom of the secondary purlin 8 by connectors. S82, install vapor barrier 141, non-woven fabric 142 and sound-absorbing cotton 143. The vapor barrier 141, non-woven fabric 142 and sound-absorbing cotton 143 are laid sequentially between adjacent secondary purlins 8, and the sound-absorbing cotton 143 fills the gap between adjacent secondary purlins 8. S83, Install waterproof layer support assembly 144, such as Figure 18 As shown, the waterproof layer support assembly 144 includes a support angle steel 144a fixed on the secondary purlin 8 and a support mesh 144b laid on the secondary purlin 8 and the support angle steel 144a. The support angle steel 144a is fixed to the upper edge of the secondary purlin 8 by a connector and its top is flush with the top. The support mesh 144b is laid on the upper part of the support angle steel 144a and the secondary purlin 8 and is fixed by a fastener. S84, Install waterproof membrane and thermal insulation rock wool. Lay the waterproof membrane 145 on the support net 144b along the radial direction of the roof, with an overlap length of not less than 100mm. Lay the thermal insulation rock wool 146 on the waterproof membrane 145.

[0039] In step S9, the steel structure roof is divided into a high curvature section, a variable curvature section, and a low curvature section from the center of the roof along the radial direction of the roof according to the curvature of the roof. like Figure 11 As shown, the roof panel of the high curvature section is made of metal single panel 18, which is laid on the roof support layer composed of supporting keel 15. like Figure 12 As shown, the roof panel of the variable curvature section adopts a fan-shaped roof panel 19, which is laid on the roof support layer composed of support components, including a support 16 and a Z-shaped bracket 17. like Figure 13 As shown, the roof panel of the low curvature section adopts a fan-shaped roof panel 19, which is laid on the roof support layer composed of supports 16. Step S9 specifically includes the following steps: S91, Install the roof support layer. In the high curvature section, fix the support keel 15 to the top of the secondary purlin connector 10 through the connector. The support keel 15 is distributed radially along the roof. In the variable curvature section, determine the arrangement position of the support components according to the layout drawing of the fan-shaped roof panel 19, fix the bracket 17 to the secondary purlin 8, and fix the support 16 to the bracket 17. In the low curvature section, determine the arrangement position of the support 16 according to the layout drawing of the fan-shaped roof panel 19, and fix the support 16 directly to the secondary purlin 8. S92, Install the roof panel. In the high curvature section, lay the metal single panel 18 on the supporting keel 15 through the connector. In the variable curvature section and low curvature section, according to the position of the support 16, hoist the fan-shaped roof panel 19 to the roof and adjust its position. Use the method of first manually locking the edge and then electric locking the edge to fix the fan-shaped roof panel 19 to the support 16. Among them, the roof panels at the joints between high curvature sections and variable curvature sections, and between variable curvature sections and low curvature sections, adopt a slope-following overlap, such as... Figure 14 and Figure 15 As shown, the roof panel at the higher position overlaps the roof panel at the lower position; the end of the roof panel at the higher position is connected to a slope slab 23, which extends downward and covers the gap at the overlap; the end of the roof panel at the lower position is bent upward to form a water-blocking edge, and the end has a foam plug 24.

[0040] like Figure 11 As shown, in the high curvature section, the height of the secondary purlin support 101 is adapted to the required support height of the roof panel, and a horizontal transition plate is fixed on its top. The supporting keel 15 is fixed to the transition plate through connectors. The waterproof membrane extends upward close to the outer surface of the secondary purlin support 101 and abuts against the joint between the secondary purlin support 101 and the transition plate. The extension section of the waterproof membrane is clamped and fixed to the outer surface of the secondary purlin support 101 by clamps 22.

[0041] In the variable curvature section and the low curvature section: a locking clip 161 is fixed to the outside of the support 16 at the uppermost and lowermost ends of the respective sections. The locking clip 161 is located on the outside of the fan-shaped roof panel 19 and clamps the locking edge engagement section between the fan-shaped roof panel 19 and the support 16. In this embodiment, the locking clip 161 is fixed to the outside of the support 16 at the uppermost ring of the respective sections, and the locking clip 161 is fixed to the outside of the support 16 at the lowermost two rings.

[0042] A windproof support 25 is added to the upper end of the variable curvature section and the low curvature section. The windproof support 25 in the low curvature section is fixed to the secondary purlin 8, and the windproof support 25 in the variable curvature section is fixed to the secondary purlin 8 by a U-shaped bracket 17. The interlocking section between the fan-shaped roof panel 19 and the windproof support 25 is provided with a fastener 251. In this embodiment, the fastener 251 is a stainless steel bolt.

[0043] Step S10 specifically includes the following steps: S101, Install gutter 112. The prefabricated gutter 112 is hoisted to the inside of the U-shaped gutter keel 111 for assembly. The gutter 112 is pressed and fixed by the gutter pressure blocks on both sides. A gutter expansion joint is set at intervals. S102, Install the eaves panel. The eaves panel 122 is laid tightly against the outside of the eaves joists 121 through connectors.

[0044] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A construction method for a large-span elliptical steel structure roof, wherein the steel structure roof comprises, from bottom to top, a truss layer, a main purlin layer, a secondary purlin layer, and a roof layer, characterized in that, Includes the following steps: S1, Truss layer structure division, the truss layer is an elliptical grid structure composed of main truss (4), connecting truss (5) and cantilever truss (6), the main truss (4) includes a central ring truss (41) located at the center of the roof and a radially distributed structural truss (42). S2, construction hoisting support structure, the hoisting support structure includes an outer protective structure column (1), an inner support structure column (2) and a temporary inner support frame (3), the temporary inner support frame (3) is located directly below the central annular truss (41), the inner support structure column (2) is arranged in two rows, and its overall distribution is parallel to the minor axis of the ellipse and symmetrical about the minor axis of the ellipse; S3, Ground assembly and hoisting unit, the main truss (4) is assembled on the ground frame and the main purlins (7) at the corresponding positions are pre-installed to form a hoisting unit. The main purlins (7) are fixed on the main truss (4) by the main purlin connectors (9) and are distributed radially along the roof. S4, hoist the hoisting unit in stages and install the connecting truss (5) and cantilever truss (6): S41, the hoisting unit containing the central annular truss (41) is hoisted in two parts, with the temporary inner support frame (3) as the installation base point; S42, hoisting unit containing the two radial trusses (42) located at the major axis of the ellipse; S43, hoisting the hoisting unit adjacent to the already installed hoisting unit; S44, after the adjacent radial truss (42) is installed in place, install the connecting truss (5) between the two and the cantilever truss (6) at the end. S45, repeat steps S43 and S44 in the hoisting sequence radiating from the major axis to the minor axis of the ellipse until all hoisting units are in place; S5, Main purlin adjustment and installation: After the hoisting unit is installed in place, the elevation of the main purlin (7) is re-measured and adjusted, and the main purlin (7) is installed with the connecting truss (5) and the cantilever truss (6) as the installation base points. S6, Secondary purlin installation: After the truss layer and main purlin layer are installed and unloaded and stabilized, the secondary purlins (8) are installed. The secondary purlins (8) are fixed to the main purlins (7) by the secondary purlin connectors (10), and they are distributed along the circumferential direction of the roof. S7, install gutter joists and eaves joists; S8, Pave the roof base plate (13) and waterproof and thermal insulation composite layer (14). S9, Install the roof support layer and roof panels; S10, install the gutter board (112) and the eaves panel (122).

2. The construction method according to claim 1, characterized in that, The temporary internal support frame (3) is composed of several uniformly arranged unit support frames (31). The unit support frame (31) includes a lattice tower column (311), a working platform (312) set at the top of the lattice tower column (311), and a ladder (313) installed on one side of the lattice tower column (311). The bottom of the lattice-type tower column (311) is fixed to the embedded parts of the concrete foundation; A tie beam (32) connects the tops of adjacent lattice tower columns (311). The top surface of the work platform (312) is provided with a negative pressure plate, and the central annular truss (41) is fixed to the temporary inner support frame (3) through the negative pressure plate; The lattice-type tower column (311) is provided with several sets of guy ropes (33) at intervals along the height direction. The other end of the guy rope (33) extends away from the center of the roof and is fixed to the foundation structure.

3. The construction method according to claim 1, characterized in that, In step S4, the top of the hoisting unit where the structural radial truss (42) is located is fixed to the central annular truss (41), and the bottom is fixed to the outer protective structure column (1); When the pre-set installation node of the hoisting unit near the major axis of the ellipse corresponds to the position of the inner support structure column (2) along the length direction, the hoisting unit is fixed to the top of the inner support structure column (2) through the pre-set installation node.

4. The construction method according to claim 3, characterized in that, The structural radial truss (42) is fixed to the outer protective structure column (1) and the inner support structure column (2) by the seismic ball hinge support (20); the top of the outer protective structure column (1) and the inner support structure column (2) is provided with a pre-embedded plate (21), and the base of the seismic ball hinge support (20) is fixed on the pre-embedded plate (21).

5. The construction method according to claim 1, characterized in that, The main purlin connector (9) includes a fixed seat (91) connected to the truss layer, a main purlin bracket (92) connected to the fixed seat (91), and a main purlin ear plate (93) connecting the main purlin bracket (92) and the main purlin (7); the secondary purlin connector (10) includes a secondary purlin bracket (101) connected to the main purlin (7), and a secondary purlin ear plate (102) connecting the secondary purlin bracket (101) and the secondary purlin (8); Both the main purlin ear plate (93) and the secondary purlin ear plate (102) are square plate structures, and several connecting holes are provided on their surfaces. The connecting holes on the main purlin ear plate (93) fixed at the higher end of the main purlin (7) are round holes, and the connecting holes on the main purlin ear plate (93) fixed at the lower end of the main purlin (7) are transverse elongated holes. The connecting holes on the secondary purlin ear plate (102) are transverse elongated holes.

6. The construction method according to claim 1, characterized in that, It also includes step S0, verification and adjustment: using finite element analysis software to perform a full-process simulation verification of the construction of the overall steel structure; in the full-process simulation verification, stress and deformation monitoring are performed on the key stress-bearing parts of the steel structure roof, and the arrangement scheme of the internal support structure column (2) and the temporary internal support frame (3) is optimized by analyzing the load combination of different construction stages.

7. The construction method according to claim 1, characterized in that, The steel structure roof is provided with a gutter assembly (11) and an eaves assembly (12) in sequence at the end. The gutter assembly (11) includes a U-shaped gutter keel (111) and a gutter board (112). The eaves assembly (12) includes an eaves keel (121) and an eaves panel (122). In step S7, the U-shaped gutter keel (111) is assembled into several assembly units on the ground, and then the units are hoisted and fixed at the end of the main purlin layer and spliced. The eaves keel (121) extends along the outside of the cantilever truss (6), with one end fixed to the outside of the U-shaped gutter keel (111) and the other end fixed to the vertical bar at the end of the main truss (4).

8. The construction method according to claim 1, characterized in that, The waterproof and thermal insulation composite layer (14) is composed of a vapor barrier membrane (141), non-woven fabric (142), sound-absorbing cotton (143), waterproof layer support assembly (144), waterproof roll material (145) and thermal insulation rock wool (146) arranged sequentially from bottom to top; Step S8 specifically includes the following steps: S81, Install the roof base plate (13). The roof base plate (13) is constructed by overlapping it from high to low along the slope. The overlap is located at the bottom of the secondary purlin (8). The overlap length is not less than 100mm. The roof base plate (13) is fixed to the bottom of the secondary purlin (8) by the connector. S82, install a vapor barrier membrane (141), non-woven fabric (142) and sound-absorbing cotton (143), the vapor barrier membrane (141), non-woven fabric (142) and sound-absorbing cotton (143) are laid in sequence between adjacent secondary purlins (8), and the sound-absorbing cotton (143) fills the gap between adjacent secondary purlins (8); S83, Install the waterproof layer support assembly (144), the waterproof layer support assembly (144) includes a support angle steel (144a) fixed on the secondary purlin (8) and a support mesh (144b) laid on the secondary purlin (8) and the support angle steel (144a). The support angle steel (144a) is fixed to the upper edge of the secondary purlin (8) by a connector and the top end is flush. The support mesh (144b) is laid on the upper part of the support angle steel (144a) and the secondary purlin (8) and fixed by a fastener. S84, Install waterproof membrane and thermal insulation rock wool. Lay the waterproof membrane (145) on the support net (144b) along the radial direction of the roof, with an overlap length of not less than 100mm. Lay the thermal insulation rock wool (146) on the waterproof membrane (145).

9. The construction method according to claim 1, characterized in that, The steel structure roof is divided into high curvature section, variable curvature section and low curvature section from the center of the roof along the radial direction of the roof according to the curvature of the roof; The roof panel of the high curvature section is made of metal veneer (18), which is laid on the roof support layer composed of supporting keel (15); The roof panel of the variable curvature section adopts a fan-shaped roof panel (19), which is laid on a roof support layer composed of support components, including a support (16) and a bracket (17). The roof panel of the low curvature section adopts a fan-shaped roof panel (19), which is laid on the roof support layer composed of supports (16); Step S9 specifically includes the following steps: S91, Install the roof support layer. In the high curvature section, fix the support keel (15) to the top of the secondary purlin connector (10) through the connector. The support keel (15) is distributed radially along the roof. In the variable curvature section, determine the arrangement position of the support components according to the layout drawing of the fan-shaped roof panel (19), fix the bracket (17) on the secondary purlin (8), and fix the support (16) on the bracket (17). In the low curvature section, determine the arrangement position of the support (16) according to the layout drawing of the fan-shaped roof panel (19), and fix the support (16) directly on the secondary purlin (8). S92, Install the roof panel. In the high curvature section, lay the metal single panel (18) on the supporting keel (15) through the connector. In the variable curvature section and the low curvature section, according to the position of the support (16), hoist the fan-shaped roof panel (19) to the roof and adjust its position. The fan-shaped roof panel (19) is locked to the support (16) by first manually locking the edges and then by electric locking. Among them, the roof panels at the joints between the high curvature section and the variable curvature section, and between the variable curvature section and the low curvature section, adopt the slope overlap.

10. The construction method according to claim 1, characterized in that, In step S10, the prefabricated gutter board (112) is hoisted to the inside of the U-shaped gutter keel (111) for assembly. The gutter board (112) is pressed and fixed by gutter pressure blocks on both sides, and a gutter expansion joint is set at intervals. The eaves panel (122) is laid tightly against the outside of the eaves keel (121) through connectors.

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