A large-span trapezoidal space steel tube truss concrete floor structure

Abstract

A large-span trapezoidal space steel tube truss concrete floor structure includes a concrete floor and a large-span trapezoidal space steel tube truss, and the concrete floor directly bearing the floor load is arranged on the T-shaped support of the three-tube upper chord of the large-span trapezoidal space steel tube truss; the basic unit of the large-span trapezoidal space steel tube truss is a bay, each bay is composed of a three-tube upper chord, a two-tube lower chord, a four-cornered pyramid diagonal web, an upper chord horizontal bar and a lower chord horizontal bar, and the cross-sectional shape of the basic unit is an inverted trapezoid arranged in a triangular shape; the large-span trapezoidal space steel tube truss adopts the intersecting connection of the steel tube direct welding node; the concrete floor adopts an assembled prefabricated plate or a steel-concrete composite floor. The present invention has a reasonable structure, simple construction, clear force transmission, and convenient installation. The floor secondary beam and the out-of-plane secondary truss of the space truss are not set, the steel consumption is small, the rigidity is large, the bearing capacity is high, the spanning capacity is strong, the comfort is good, and the mechanical properties are excellent.

Description

Technical Field

[0001] The invention belongs to the field of civil engineering, and in particular relates to a large-span trapezoidal space steel tube truss concrete floor structure. Background Art

[0002] In recent years, public buildings with large-span roofs have become more and more common, such as stadiums, exhibition centers, theaters, industrial plants, etc. The roof structures of this type of buildings are diverse, including basic forms such as arches, plane trusses, three-dimensional trusses, grids, lattice shells, beam string and chord-supported domes. The roof enclosure structure mainly adopts lightweight metal roofs or membrane materials, which are considered as non-walkable roofs. However, for walkable floors and roofs, due to the large live loads, lightweight roofs cannot guarantee the bearing capacity and stiffness requirements, so concrete floor slabs are required to replace them. At the same time, the significant increase in the dead load and live load of the concrete floor slab will make it difficult for the above-mentioned structural forms to meet their mechanical properties, and the economy is poor. Summary of the invention

[0003] The purpose of the present invention is to provide a large-span trapezoidal spatial steel tube truss concrete floor structure in view of the above-mentioned problems in the prior art, which has the advantages of rich architectural form, light shape, and convenient pipeline crossing, and has a reasonable structure, simple construction, clear force transmission, and convenient installation. It does not set floor secondary beams and out-of-plane secondary trusses of spatial trusses. The overall structure has a small amount of steel, high rigidity, high bearing capacity, strong spanning ability, good comfort, and excellent mechanical properties.

[0004] In order to achieve the above-mentioned purpose, the present invention proposes a large-span trapezoidal space steel tube truss concrete floor structure with the following technical solutions: comprising a large-span trapezoidal space steel tube truss and a concrete floor slab, and the concrete floor slab directly bearing the floor load is arranged on the T-shaped support of the three-tube upper chord rod of the trapezoidal space steel tube truss; the basic unit of the large-span trapezoidal space steel tube truss is a bay, and each bay is composed of a three-tube upper chord rod, a two-tube lower chord rod, a four-cornered pyramid diagonal web rod, an upper chord horizontal rod, and a lower chord horizontal rod; the cross-sectional shape of the basic unit is It is an inverted trapezoid arranged in triangles; the large span is formed by splicing several basic units of the trapezoidal space steel tube truss; the three-tube upper chord bars and the two-tube lower chord bars of the large-span trapezoidal space steel tube truss are the main pipes; the four-cornered pyramid diagonal web bars, the upper chord horizontal bars and the lower chord horizontal bars are the branch pipes; the large-span trapezoidal space steel tube truss adopts the intersecting connection of the steel tube direct welding nodes; the concrete floor slab is an assembled prefabricated slab or a steel-concrete composite floor slab; the connection between the concrete floor slab and the large-span trapezoidal space steel tube truss is fixed by a T-shaped support and a bolt shear key.

[0005] As a preferred solution of the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, the large-span trapezoidal space steel tube truss is in the form of a parallel chord truss, a trapezoidal truss, a variable height curved truss or an arched truss.

[0006] As a preferred solution of the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, the rods of the basic unit are all round steel tubes, and the steel tube type is rolled or welded; the ratio of the outer diameter to the wall thickness of the compression rod of the large-span trapezoidal space steel tube truss does not exceed ε k is the steel grade correction factor.

[0007] As a preferred solution of the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, the in-plane and out-of-plane calculated lengths of the three-tube upper chord and the two-tube lower chord are 0.9 times the node center distance S j0 , j0 =1, 2, and 0.9S j0 The stability is verified according to the lattice compression rod; the in-plane and out-of-plane calculation lengths of the tetrahedral diagonal web rod, upper chord horizontal rod and lower chord horizontal rod are 0.8 times the node center distance S j1 , j1 =3, 4, 5.

[0008] As a preferred solution for the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, the external dimensions of the main pipe are not less than the external dimensions of the branch pipe, the wall thickness of the main pipe is not less than the wall thickness of the branch pipe, and the branch pipe shall not be inserted into the main pipe at the connection between the branch pipe and the main pipe; the angle between the main pipe and the branch pipe or the axis of the branch pipe is not less than 30°; the branch pipe ends of the large-span trapezoidal space steel tube truss are cut by an automatic pipe cutting machine, and the bevel is not cut when the wall thickness of the branch pipe is less than 6 mm.

[0009] As a preferred solution for the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, the eccentricity of the branch pipe and the main pipe connection node of the large-span trapezoidal space steel tube truss does not exceed -0.55≤e / D≤0.25, and the influence of the eccentric bending moment is considered for the compressive main pipe, while it can be ignored for the tensile main pipe and the node, and the eccentric bending moment M=ΔN·e, e is the eccentricity, D is the outer diameter of the circular pipe main pipe (mm), and ΔN is the difference in axial force of the main pipes on both sides.

[0010] As a preferred solution for the above-mentioned large-span trapezoidal spatial steel tube truss concrete floor structure, the branch pipes of the large-span trapezoidal spatial steel tube truss adopt K-shaped nodes with gaps and overlapping K-shaped nodes, and the gap between adjacent branch pipes welded on the surface of the main pipe is not less than 2 times the wall thickness of the two branch pipes, and the weld around the overlapping branch pipe is 2 times the wall thickness of the branch pipe.

[0011] As a preferred solution of the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, the connecting welds between the branch pipe and the main pipe are continuously welded along the whole circumference and smoothly transitioned, the weld form adopts fillet welds along the whole circumference, or partially adopts butt welds, and partially adopts fillet welds. For the area where the angle between the branch pipe wall and the main pipe wall is greater than or equal to 120°, butt welds or fillet welds with grooves are adopted, the weld leg size of the fillet weld is not greater than 2 times the wall thickness of the branch pipe, and the weld around the lapped branch pipe is 2 times the wall thickness of the branch pipe; the large-span trapezoidal space steel tube truss with direct welding nodes, the plane K-shaped node of the branch pipe overlap, the overlap rate satisfies 25%≤η ov ≤100%, and ensure that the continuous welds between the overlapping branches can reliably transmit internal forces.

[0012] As a preferred solution for the above-mentioned large-span trapezoidal spatial steel tube truss concrete floor structure, when the external dimensions of the overlapping branches are different, the one with the smaller external dimension is overlapped on the one with the larger dimension; when the wall thicknesses of the branches are different, the one with the smaller wall thickness is overlapped on the one with the larger wall thickness, and the branch pipe that bears the axial pressure is at the bottom.

[0013] As a preferred solution for the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, when the node cannot meet the bearing capacity requirements, a transverse stiffening plate is arranged in the main pipe or a reinforcement plate is attached to the surface of the main pipe to strengthen it.

[0014] As a preferred solution for the above-mentioned large-span trapezoidal spatial steel tube truss concrete floor structure, the T-shaped support is welded on the three-tube upper chord of the large-span trapezoidal spatial steel tube truss, and the supporting surface of the T-shaped support is parallel to the bottom of the concrete slab.

[0015] As a preferred solution for the above-mentioned large-span trapezoidal spatial steel tube truss concrete floor structure, the stud shear key is arranged perpendicular to the supporting surface of the T-shaped support; the diameter of the stud shear key is not less than 16 mm, and the length and spacing are not less than 4 times the diameter.

[0016] As a preferred solution for the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, the concrete floor is arranged on the T-shaped support of the three-tube upper chord of the large-span trapezoidal space steel tube truss; the supporting length of the prefabricated panel on the T-shaped support is not less than 100 mm, and it is connected to the T-shaped support by corner welds, and the joint width between the prefabricated panels is not less than 20 mm; the supporting length of the steel-concrete composite floor on the T-shaped support is not less than 100 mm, and the floor decking of the steel-concrete composite floor is penetrated and welded to the T-shaped support by bolt shear keys.

[0017] As a preferred solution for the above-mentioned large-span trapezoidal spatial steel tube truss concrete floor structure, the span of the assembled prefabricated panel is S1, S3 or S6; the span of the steel-concrete composite floor is S3 and S6.

[0018] The large-span trapezoidal space steel tube truss has a span of L, a column spacing of B, a truss height of H, a three-tube upper chord section spacing of S1, a two-tube lower chord section spacing of S2, an upper chord rod spacing of S3, and a lower chord rod spacing of S4; a four-cornered pyramid diagonal web spacing of S5, and a spacing between the outer upper chord rods of the i-th and i+1-th adjacent trapezoidal space steel tube trusses of S6.

[0019] As a preferred solution for the above-mentioned large-span trapezoidal space steel tube truss concrete floor structure, the concrete floor is not provided with secondary beams; and no secondary trusses are provided outside the planes of the adjacent trapezoidal space steel tube trusses of the i-th frame and the i+1-th frame.

[0020] Compared with the prior art, the present invention has the following beneficial effects: the concrete floor slab that directly bears the floor load is arranged on the T-shaped support of the three-tube upper chord of the large-span trapezoidal space steel tube truss. The basic unit of the large-span trapezoidal space steel tube truss is composed of a three-tube upper chord, a two-tube lower chord, a four-corner pyramid diagonal web, an upper chord horizontal bar and a lower chord horizontal bar. The cross-section is an inverted trapezoid arranged in a triangular shape. The space truss steel tubes are directly welded and connected at the nodes, which achieves: 1. The building has a rich shape, a light shape, and is convenient for pipelines to pass through. 2. The structure is reasonable, the construction is simple, the force transmission is clear, and the installation is convenient. 3. The span of the floor slab is small, and no secondary beams are set. 4. The overall stability of the large-span trapezoidal space truss is good outside the plane, and no secondary trusses are set. 5. The structure uses a small amount of steel, has a large rigidity, a high bearing capacity, a strong spanning capacity, and a good comfort level. 6. The mechanical properties of the overall structure are excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the large-span trapezoidal space steel tube truss concrete floor structure of the present invention;

[0022] In the attached figure: 1-basic unit; 2-three-tube upper chord; 3-two-tube lower chord; 4-quadrangular pyramid diagonal web; 5-upper chord horizontal bar; 6-lower chord horizontal bar; 7-T-shaped support; 8-stud shear key; 9-assembled prefabricated panel; 10-steel-concrete composite floor. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0024] See also Figure 1The present invention comprises a large-span trapezoidal space steel tube truss and a concrete floor, and the concrete floor directly bearing the floor load is arranged on the T-shaped support of the three-tube upper chord rod 2 of the large-span trapezoidal space steel tube truss; the basic unit 1 of the large-span trapezoidal space steel tube truss is a section, and each section is composed of a three-tube upper chord rod 2, a two-tube lower chord rod 3, a four-cornered pyramid diagonal web rod 4, an upper chord horizontal rod 5, and a lower chord horizontal rod 6; the cross-sectional shape of the basic unit is an inverted trapezoid arranged in triangles; the large span is composed of a trapezoidal space The steel tube truss is composed of several basic units spliced ​​together; the three-tube upper chord rod 2 and the two-tube lower chord rod 3 of the large-span trapezoidal space steel tube truss are the main pipes; the four-cornered pyramid diagonal web rod 4, the upper chord horizontal rod 5 and the lower chord horizontal rod 6 are the branch pipes; the large-span trapezoidal space steel tube truss adopts the intersecting connection of the steel tube direct welding nodes; the concrete floor is an assembled prefabricated panel 9 or a steel-concrete composite floor 10; the connection between the concrete floor and the large-span trapezoidal space steel tube truss is fixed by a T-shaped support 7 and a bolt shear key 8.

[0025] In this embodiment, the rods of the basic unit 1 are all round steel pipes, and the steel pipes can be rolled or welded.

[0026] In this embodiment, the large-span trapezoidal space steel tube truss with directly welded nodes has an external dimension of the main pipe not less than that of the branch pipe, a wall thickness of the main pipe not less than that of the branch pipe, and the branch pipe shall not be inserted into the main pipe at the connection between the branch pipe and the main pipe; the angle between the main pipe and the branch pipe or the axis of the branch pipe is not less than 30°; the branch pipe ends of the large-span trapezoidal space steel tube truss are cut by an automatic pipe cutting machine, and the bevel is not cut when the wall thickness of the branch pipe is less than 6 mm.

[0027] In this embodiment, the large-span trapezoidal spatial steel pipe truss with direct welding nodes adopts K-shaped nodes with gaps and overlapping K-shaped nodes for the branches, and the gap between adjacent branches welded on the surface of the main pipe is not less than 2 times the wall thickness of the two branches, and the weld around the overlapping branch is 2 times the wall thickness of the branch.

[0028] In this embodiment, the large-span trapezoidal space steel tube truss with direct welding nodes, the connecting welds between the branch pipe and the main pipe are continuously welded along the entire circumference and smoothly transitioned, the weld form adopts fillet welds along the entire circumference, or partially adopts butt welds, and partially adopts fillet welds. For the area where the angle between the branch pipe wall and the main pipe wall is greater than or equal to 120°, a butt weld or a fillet weld with a groove is adopted, the weld leg size of the fillet weld is not greater than 2 times the wall thickness of the branch pipe, and the weld around the overlapping branch pipe is 2 times the wall thickness of the branch pipe; the large-span trapezoidal space steel tube truss with direct welding nodes, the plane K-shaped node where the branch pipes are overlapped, the overlap rate meets the requirements, and it is ensured that the continuous welds between the overlapping branch pipes can reliably transmit the internal force.

[0029] In this embodiment, for the large-span trapezoidal spatial steel tube truss with directly welded nodes, when the external dimensions of the overlapping branches are different, the one with the smaller external dimension is overlapped on the one with the larger dimension, and when the wall thicknesses of the branches are different, the one with the smaller wall thickness is overlapped on the one with the larger wall thickness, and the branch pipe that bears the axial pressure is at the bottom.

[0030] In this embodiment, the T-shaped support 7 is welded on the three-tube upper chord 2 of the large-span trapezoidal space steel tube truss, and the supporting surface of the T-shaped support 7 is parallel to the bottom of the concrete slab.

[0031] In this embodiment, the bolt shear key 8 is arranged perpendicular to the supporting surface of the T-shaped support 7; the diameter of the bolt shear key 8 is not less than 16 mm, and the length and spacing are not less than 4 times the diameter.

[0032] In this embodiment, the concrete floor slab 9 or 10 is arranged on the T-shaped support 7 of the three-tube upper chord 2 of the large-span trapezoidal space steel tube truss; the supporting length of the prefabricated panel 9 on the T-shaped support 7 is not less than 100 mm, and it is connected to the T-shaped support 7 by corner welds, and the joint width between the prefabricated panels 9 is not less than 20 mm; the supporting length of the steel-concrete composite floor slab 10 on the T-shaped support 7 is not less than 100 mm, and the floor decking of the steel-concrete composite floor slab 10 is penetrated and welded with the T-shaped support 7 by bolt shear keys 8.

[0033] In the actual processing and splicing process, firstly, according to the form of the large-span trapezoidal space steel tube truss, the upper chord plane members, the lower chord plane members and the supporting frames of the four-corner pyramid are respectively manufactured; secondly, the three-tube upper chord members 2, the upper chord horizontal members 5 and the T-shaped supports 7 are arranged on the supporting frames of the upper chord plane members; the two-tube lower chord members 3 and the lower chord horizontal members 6 are arranged on the supporting frames of the lower chord plane members; all of them are connected by intersecting welds to complete the assembly of the upper and lower chord plane members; and with the lower chord plane members as the support, the supporting frame of the four-corner pyramid is moved to the installation position, and the four-corner pyramid diagonal web members 4 are intersectingly welded to form a space support platform; thereby, the upper chord plane members are further erected and intersectingly welded, and finally the overall assembly of the trapezoidal space steel tube truss is completed, and it can be stored, transported and installed on site. During actual construction, the large-span trapezoidal space steel tube truss is hoisted onto the support frame by hoisting equipment, and after being hoisted into place on site and fixed to the support, the concrete floor is installed according to the design selection. If the assembled prefabricated panel 9 is selected, the bottom of the prefabricated panel rib is supported on the top surface of the T-shaped support 7, and is connected by corner welds; if the steel-concrete composite floor 10 is selected, the floor deck is laid first, and the stud shear key 8 and the floor deck are penetrated and welded to the T-shaped support 7 according to the arrangement spacing, and the distribution steel bars are laid, and then the concrete is poured. After a certain period of curing, the strength reaches the design index to form the steel-concrete composite floor 10. Finally, the production of the entire large-span trapezoidal space steel tube truss concrete floor structure is completed.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A large-span trapezoidal space steel tube truss concrete floor structure, characterized by: The invention comprises a concrete floor and a plurality of long-span trapezoidal space steel tube trusses arranged according to column spacing, wherein the concrete floor directly bearing the floor load is arranged on a T-shaped support (7) of a three-tube upper chord bar (2) of the long-span trapezoidal space steel tube truss; the basic unit (1) of the long-span trapezoidal space steel tube truss is a section, and each section is composed of a three-tube upper chord bar (2), a two-tube lower chord bar (3), a four-cornered pyramid diagonal web bar (4), an upper chord horizontal bar (5) and a lower chord horizontal bar (6); the cross-sectional shape of the basic unit (1) is an inverted trapezoid arranged in triangles; the long-span trapezoidal space steel tube truss is a T-shaped support (7) ... The trapezoidal space steel tube truss is formed by splicing a plurality of basic units; the three-tube upper chord rod (2) and the two-tube lower chord rod (3) of the large-span trapezoidal space steel tube truss are main pipes, and the four-cornered pyramid diagonal web rod (4), the upper chord horizontal rod (5) and the lower chord horizontal rod (6) are branch pipes; the large-span trapezoidal space steel tube truss adopts the intersecting connection of steel tube direct welding nodes; the concrete floor adopts the assembled prefabricated plate (9) or the steel-concrete composite floor (10); the connection between the concrete floor and the large-span trapezoidal space steel tube truss is fixed by a T-shaped support (7) and a bolt shear key (8); The rods of the basic unit (1) are all round steel pipes, and the steel pipe type is rolled or welded; the ratio of the outer diameter to the wall thickness of the compression rod of the large-span trapezoidal space steel pipe truss does not exceed ε k is the steel grade correction coefficient; the in-plane and out-of-plane calculated lengths of the three-tube upper chord (2) and the two-tube lower chord (3) are 0.9 times the node center distance S j0 , j0 =1, 2, and 0.9S j0 The stability is verified by lattice compression rod; the in-plane and out-of-plane calculated lengths of the quadrangular pyramid diagonal web rod (4), the upper chord horizontal rod (5) and the lower chord horizontal rod (6) are 0.8 times the node center distance S j1 , j1 =3, 4, 5.

2. The large-span trapezoidal space steel tube truss concrete floor structure according to claim 1 is characterized by: The large-span trapezoidal space steel tube truss is in the form of a parallel chord truss, a trapezoidal truss, a variable-height curved truss or an arched truss.

3. The large-span trapezoidal space steel tube truss concrete floor structure according to claim 1 is characterized by: The external dimensions of the main pipe are not less than those of the branch pipe, the wall thickness of the main pipe is not less than that of the branch pipe, and the branch pipe is not inserted into the main pipe at the connection between the branch pipe and the main pipe; the angle between the main pipe and the branch pipe or the axis of the branch pipe is not less than 30°; the branch pipe ends of the large-span trapezoidal space steel pipe truss are cut, and the groove is not cut when the wall thickness of the branch pipe is less than 6mm.

4. The large-span trapezoidal space steel tube truss concrete floor structure according to claim 1 is characterized by: The eccentricity at the connection node between the branch pipe and the main pipe shall not exceed -0.55≤e / D≤0.25; and the influence of the eccentric bending moment is considered for the compression main pipe, while it is ignored for the tension main pipe and the node. The eccentric bending moment M=ΔN·e, where e is the eccentricity, D is the outer diameter of the main pipe, and ΔN is the difference in the axial force of the main pipe on both sides.

5. The large-span trapezoidal space steel tube truss concrete floor structure according to claim 1 is characterized by: The branch pipes adopt K-shaped nodes with gaps and overlapping K-shaped nodes, and the gap between adjacent branch pipes welded on the surface of the main pipe shall not be less than twice the wall thickness of the two branch pipes, and the weld around the overlapping branch pipe shall be twice the wall thickness of the branch pipe.

6. The large-span trapezoidal space steel tube truss concrete floor structure according to claim 5 is characterized by: The connecting welds between the branch pipe and the main pipe are welded continuously along the whole circumference and smoothly transitioned; the weld form adopts fillet welds along the whole circumference, or partially adopts butt welds and partially adopts fillet welds; for the area where the angle between the branch pipe wall and the main pipe wall is greater than or equal to 120°, butt welds or fillet welds with grooves are adopted, the leg size of the fillet weld is not greater than 2 times the wall thickness of the branch pipe, and the weld around the lapped branch pipe is 2 times the wall thickness of the branch pipe; for the plane K-shaped node of the branch pipe lap, the lap rate meets 25%≤η ov ≤100%, and the continuous welds between overlapping branches can reliably transmit internal forces; when the external dimensions of the overlapping branches are different, the one with the smaller external dimension shall be overlapped on the one with the larger dimension; when the wall thicknesses of the branches are different, the one with the smaller wall thickness shall be overlapped on the one with the larger wall thickness, and the branch that bears the axial pressure shall be arranged at the bottom.

7. The large-span trapezoidal space steel tube truss concrete floor structure according to claim 1 is characterized by: The T-shaped support (7) is welded on the three-tube upper chord (2), and the supporting surface of the T-shaped support (7) is parallel to the bottom of the concrete floor; the bolt shear key (8) is arranged perpendicular to the supporting surface of the T-shaped support (7); the diameter of the bolt shear key (8) is not less than 16 mm, and the length and spacing are not less than 4 times the diameter.

8. The large-span trapezoidal space steel tube truss concrete floor structure according to claim 1 is characterized by: The concrete floor slab is arranged on the T-shaped support (7) of the three-tube upper chord (2) of the large-span trapezoidal space steel tube truss. When the assembled prefabricated plate (9) is used, the supporting length of the assembled prefabricated plate (9) on the T-shaped support (7) is not less than 100 mm, and the assembled prefabricated plate (9) is connected to the T-shaped support (7) by corner welds, and the joint width between the assembled prefabricated plates (9) is not less than 20 mm. When the steel-concrete composite floor slab (10) is used, the supporting length of the steel-concrete composite floor slab (10) on the T-shaped support (7) is not less than 100 mm, and the floor deck of the steel-concrete composite floor slab (10) is penetrated and welded to the T-shaped support (7) by bolt shear keys (8).

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