Steel-concrete combined roof truss unit and system based on external prestressing and construction method

Abstract

The invention discloses a steel-concrete combined roof truss unit and system based on external prestressing and a construction method. The steel-concrete combined roof truss unit comprises a prefabricated roof truss module, a bracket column module and an external prestress adjusting module. The prefabricated roof truss module of the steel-concrete combined structure comprises a roof truss body, and a first side connecting part and a second side connecting part are formed at the two ends of the roof truss body in the length direction correspondingly. The bracket column module of the reinforced concrete structure comprises a first side bracket column and a second side bracket column, the top end of the first side bracket column is connected with the first side connecting part in a combined mode of embedding and concrete cast-in-place, and the top end of the second side bracket column is connected with the second side connecting part in a combined mode of embedding and expansion joint butt joint; the external prestress adjusting module is configured to be parallel to the length direction of the roof truss body, and the two ends of the external prestress adjusting module penetrate through the first embedded connection position between the first side bracket column and the first side connecting part and the second embedded connection position between the second side bracket column and the second side connecting part correspondingly. And meanwhile, the two ends are respectively anchored on the outer sides of the first side bracket column and the second side bracket column. The problems that an existing large-span prestressed roof truss is large in dead weight, prestress loss is difficult to monitor, and cracks are likely to be generated at the joint of the roof truss and a bracket column are solved.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, in particular to a steel-concrete combined roof truss unit, system and construction method based on external prestressing. Background Art

[0002] It is well known that in the construction of large factories and granaries in my country, due to the large span of the roof truss, a prestressed structural system is usually used. The prestressed roof truss structure can not only effectively improve the bearing capacity of the granary when subjected to snow loads, but also improve the construction accuracy of the roof truss through prefabrication in advance, reduce costs, and significantly shorten the construction period.

[0003] At present, prestressed roof trusses usually adopt concrete structures, and prestress is tensioned on the lower chord of the roof truss. There are problems such as heavy weight, difficulty in lifting, and difficulty in monitoring the loss of prestress during use.

[0004] The existing prestressed concrete roof trusses usually connect the roof trusses and the corbels by welding the corbels and the embedded steel bars in the roof trusses, or by bolting the reserved bolt holes on the corbels and the reserved bolt holes on the roof trusses. Because this consolidation method will cause a large bending moment to be generated at the connection between the roof trusses and the concrete columns during use, it is very easy to crack under the action of snow loads and temperature stresses, and there are also problems such as reduced structural strength, shortened structural service life, and increased safety hazards. Summary of the invention

[0005] The present invention aims to overcome the above-mentioned deficiencies in the related art to at least a certain extent. To this end, the present invention proposes a steel-concrete composite roof truss unit, system and construction method based on external prestressing, which has reasonable design, simple construction and good use effect, and can effectively solve the problems of the existing large-span prestressed roof truss with heavy self-weight, difficult to monitor prestress loss, and easy cracks at the connection with the corbel column.

[0006] A steel-concrete composite roof truss unit based on external prestressing according to the present invention comprises:

[0007] The prefabricated roof truss module is configured as a steel-concrete composite structure, and the prefabricated roof truss module includes a roof truss body, and the two ends of the roof truss body in the length direction are respectively formed with a first side connection part and a second side connection part;

[0008] The corbel column module is configured as a reinforced concrete structure, the corbel column module includes a first side corbel column and a second side corbel column, the top end of the first side corbel column is connected to the first side connection portion by a combination of chiming and concrete casting, and the top end of the second side corbel column is connected to the second side connection portion by a combination of chiming and expansion joint docking;

[0009] The extracorporeal prestressed pressure regulating module is configured to be arranged parallel to the length direction of the roof truss body and its two ends respectively penetrate the first interlocking connection between the first side corbel column and the first side connecting part and the second interlocking connection between the second side corbel column and the second side connecting part, and the two ends are respectively anchored to the outer sides of the first side corbel column and the second side corbel column.

[0010] According to one embodiment of the present invention, the roof truss body includes a combined body of an upper chord, a lower chord and vertical bars of a concrete structure and a supporting web member of a steel pipe structure.

[0011] According to one embodiment of the present invention, the first side corbel column comprises a first side corbel column body, and the top end of the first side corbel column body has a first reserved groove and a corbel column reserved steel bar;

[0012] The first side connection portion includes a roof truss reserved steel bar formed on the upper part of the first end of the upper chord, the roof truss reserved steel bar is used to connect with the corbel reserved steel bar to form a cast-in-place section structure, and the first reserved groove is configured to support and embed the first end of the lower chord and the first side vertical rod from the bottom and the side.

[0013] According to one embodiment of the present invention, the outer layer of the reserved steel bars of the roof truss is further wrapped with a reinforcing steel pipe, and the reserved steel bars of the roof truss are welded to the reinforcing steel pipe.

[0014] According to one embodiment of the present invention, the second side corbel column comprises a second side corbel column body, and the top end of the second side corbel column body has a second reserved groove and a first expansion joint steel;

[0015] The second side connection portion includes a second expansion joint steel formed on the upper part of the second end of the upper chord, and the second expansion joint steel is used to be arranged symmetrically with the first expansion joint steel to form an expansion joint structure. At the same time, the second reserved groove is configured to support and embed the second end of the lower chord and the second side vertical rod from the bottom and the side.

[0016] According to one embodiment of the present invention, the second expansion joint steel and the first expansion joint steel are constructed as a mirror-symmetrical F-shape, and the two form an F-shaped butt-jointed expansion joint structure; the second expansion joint steel and the first expansion joint steel are also connected in the middle by an elastic rubber strip.

[0017] According to one embodiment of the present invention, the external prestressing force adjustment module comprises external prestressing steel strands symmetrically arranged on both sides of the lower chord, and the external prestressing steel strands are parallel to the lower chord;

[0018] Two first-side prestressed tendon anchoring sections and two second-side prestressed tendon anchoring sections of an integrated structure are symmetrically arranged on both sides of the two ends of the lower chord, and the first prestressed tendon anchoring section and the second prestressed tendon anchoring section are respectively reserved with a first prestressed steel strand pipe and a second prestressed steel strand pipe;

[0019] The first side corbel column body and the second side corbel column body are respectively provided with a first prestressed tendon pipe and a second prestressed tendon pipe located in the first reserved groove and the second reserved groove;

[0020] The two ends of the extracorporeal prestressed steel strand respectively pass through the first prestressed steel strand pipe and the first prestressed tendon pipe and the second prestressed steel strand pipe and the second prestressed tendon pipe in sequence, and after the tensioning is completed, the first anchor end and the second anchor end are respectively arranged on the outside of the first side corbel column body and the second side corbel column body.

[0021] According to one embodiment of the present invention, a first arc-shaped structure is formed below the first connection portion between the first end of the lower chord and the first reserved groove, and the first arc-shaped structure includes a first inner arc formed in the first reserved groove and a first outer arc formed at the first end of the lower chord; a first reinforcing steel plate is also wrapped below and on the side of the first connection portion;

[0022] A second arc-shaped structure is present below the second connection portion between the second end of the lower chord and the second reserved groove, and the second arc-shaped structure includes a second inner arc formed in the second reserved groove and a second outer arc formed at the second end of the lower chord; a second reinforcing steel plate is also wrapped below and on the sides of the second connection portion.

[0023] A steel-concrete composite roof truss system based on external prestressing according to the present invention comprises:

[0024] Such as the steel-concrete composite roof truss unit mentioned above;

[0025] The longitudinal limiting unit is used to connect to two adjacent steel-concrete composite roof truss units. The longitudinal limiting unit includes at least one longitudinal limiting steel pipe. Multiple longitudinal limiting steel pipes are arranged at equal intervals. Both ends of each longitudinal limiting steel pipe are respectively anchored on the upper chords of the two adjacent steel-concrete composite roof truss units.

[0026] A construction method of a steel-concrete composite roof truss system based on external prestressing according to the present invention comprises the following steps:

[0027] 1) Pile foundation construction;

[0028] 2) Casting of corbel columns:

[0029] After the pile foundation construction is completed and reaches the preset strength requirement, the corbel column module is cast, and at the same time, the first reserved groove, the corbel column reserved steel bar, the second reserved groove, the reserved prestressed steel bar pipe and the first expansion joint steel are constructed;

[0030] 3) On-site prefabricated roof trusses:

[0031] The prefabricated roof truss module is manufactured according to the design drawings and the reserved groove size of the corbel column module; and during the prefabrication process, the roof truss reserved steel bars and the second expansion joint steel are respectively set at both ends of the upper chord, and the prestressed tendon anchoring sections are set at both ends of the lower chord, and the external prestressed steel strand pipe is reserved;

[0032] 4) Hoisting the roof truss:

[0033] A crane is used on site to connect the prefabricated roof truss module with the corbel column module;

[0034] 5) Tensioning external prestressing:

[0035] After the prefabricated roof truss module is hoisted, the external prestressing adjustment module is installed to tension the external prestressing of the lower chord. After the tensioning is completed, the anchor end is set;

[0036] 6) Cast-in-place section construction and expansion joint installation: After the prestressing of the lower chord is completed, the cast-in-place section structure and expansion joint structure are constructed at both ends of the roof truss;

[0037] 7) Install longitudinal support:

[0038] After the two adjacent steel-concrete composite roof truss units are installed in sequence according to step 1) to step 6), a longitudinal limit unit is installed between the two.

[0039] According to the steel-concrete composite roof truss unit, system and construction method based on external prestressing of the present invention, the reserved steel bars and expansion joint structure are matched between the corbel column module and the prefabricated roof truss module, and an external prestressing adjustment module is arranged at the connection. Thus, the reserve amount of the roof truss prestress can be conveniently monitored by applying external prestressing, which is conducive to timely re-applying prestressing and reinforcement after the loss of the roof truss prestressing is found.

[0040] Therefore, the present invention has reasonable design, simple construction and good use effect, and can effectively solve the problems of existing prestressed concrete roof trusses, such as heavy weight, difficulty in hoisting, difficulty in monitoring prestress loss, large bending moment generated at the connection between the roof truss and the corbel column during use, and cracks that are very easy to generate under the action of temperature stress.

[0041] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0043] Figure 1 It is a schematic structural diagram of some embodiments of the steel-concrete composite roof truss system based on external prestressing of the present invention.

[0044] Figure 2 It is a partial structural schematic diagram of some embodiments of the steel-concrete composite roof truss system based on external prestressing of the present invention.

[0045] Figure 3 It is a schematic diagram of the main structure of some embodiments of the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0046] Figure 4 for Figure 3 Schematic diagram of the local enlarged structure at point A in the middle.

[0047] Figure 5 It is a schematic diagram of the top view of some embodiments of the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0048] Figure 6 It is a side view structural schematic diagram of some embodiments of the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0049] Figure 7 It is a schematic diagram of the main structure of some embodiments of the prefabricated roof truss modules in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0050] Figure 8 It is a schematic diagram of the top view of some embodiments of the prefabricated roof truss modules in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0051] Fig. 9 It is a left-side structural schematic diagram of some embodiments of the prefabricated roof truss modules in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0052] Fig.10 It is a right-side structural schematic diagram of some embodiments of the prefabricated roof truss modules in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0053] Fig.11 It is a schematic diagram of the three-dimensional structure of some embodiments of the first side corbel column in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0054] Fig.12 It is a schematic diagram of the main structure of some embodiments of the first side corbel column in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0055] Fig.13 It is a side structural schematic diagram of some embodiments of the first side corbel column in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0056] Fig.14It is a schematic diagram of the three-dimensional structure of some embodiments of the second side corbel column in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0057] Fig.15 It is a schematic diagram of the main structure of some embodiments of the second side corbel column in the steel-concrete composite roof truss unit based on external prestressing of the present invention.

[0058] Fig.16 The present invention is a schematic flow chart of some embodiments of the construction method of the externally prestressed steel-concrete composite roof truss system.

[0059] Meaning of reference numerals in the figure:

[0060] 100-Steel-concrete composite roof truss system;

[0061] 10-Steel-concrete composite roof truss unit;

[0062] 11- Prefabricated roof truss modules;

[0063] 111- Roof truss body;

[0064] 1111-combined subject;

[0065] 1111-1-upper chord; 1111-1-1-roof truss reserved steel bars; 1111-1-2-second expansion joint steel; 1111-1-3-elastic rubber strip;

[0066] 1111-2-lower chord; 1111-2-1-first side prestressed tendon anchorage section; 1111-2-1-1-first prestressed steel strand pipeline; 1111-2-2-second side prestressed tendon anchorage section; 1111-2-2-1-second prestressed steel strand pipeline; 1111-2-3-first outer arc; 1111-2-4-second outer arc; 1111-2-5-first reinforcing steel plate; 1111-2-6-second reinforcing steel plate;

[0067] 1111-3-vertical pole;

[0068] 1112-supporting belly bar;

[0069] 12-Corbel column module;

[0070] 121- first side corbel column;

[0071] 1211-first side corbel column body; 1211-1-first reserved groove; 1211-1-1-first inner arc; 1211-2-corbel column reserved steel bars; 1211-3-first prestressed steel bar pipeline;

[0072] 122-second side corbel column;

[0073] 1221-second side corbel column body; 1221-1-second reserved groove; 1221-1-1-second inner arc; 1221-2-first expansion joint steel; 1221-3-second prestressed tendon pipe;

[0074] 13-Extracorporeal prestress adjustment module;

[0075] 131-external prestressed steel strand;

[0076] 1311-first anchoring end;

[0077] 1312 - second anchoring end;

[0078] 141-cast-in-place structure;

[0079] 142-Expansion joint structure;

[0080] 20-longitudinal limit unit;

[0081] 21-Longitudinal limit steel pipe. DETAILED DESCRIPTION

[0082] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0083] According to the following Figure 1-Figure 16 The present invention describes in detail the steel-concrete composite roof truss unit, system and construction method based on external prestressing.

[0084] like Figures 3 to 15 As shown, an embodiment of the present invention provides a steel-concrete composite roof truss unit based on external prestressing, including a prefabricated roof truss module 11, a corbel column module 12 and an external prestressing adjustment module 13.

[0085] In this embodiment, refer to Figure 3-10 The prefabricated roof truss module 11 is configured as a steel-concrete composite structure. The prefabricated roof truss module 11 includes a roof truss body 111. The first side connection part and the second side connection part are respectively formed at both ends of the length direction of the roof truss body 111.

[0086] Please refer to Figure 3 and Figure 7 In some embodiments of the present invention, the roof truss body 111 includes a combined body 1111 of an upper chord 1111-1, a lower chord 1111-2 and a vertical bar 1111-3 of a concrete structure and a supporting web member 1112 of a steel pipe structure.

[0087] In a specific implementation, the upper chord 1111 - 1 , the lower chord 1111 - 2 and the vertical rod 1111 - 3 can be integrally formed into the combined body 1111 , and the first side connection portion and the second side connection portion correspond to the two side ends of the entire combined body 1111 .

[0088] Furthermore, the first side connection portion includes a roof truss reserved steel bar 1111-1-1 formed at the upper part of the first end of the upper chord 1111-1 and a first interlocking connection with the corbel column module 12, and the second side connection portion includes a second expansion joint steel 1111-1-2 formed at the upper part of the second end of the upper chord 1111-1 and a second interlocking connection of the corbel column module 12, wherein the roof truss reserved steel bar 1111-1-1 and the second expansion joint steel 1111-1-2 respectively serve as a cast-in-place connection and an expansion joint joint connected with the corbel column module 12, the cast-in-place connection and the first interlocking connection together constitute the first side connection portion of the combined body 1111, and similarly, the expansion joint joint and the second interlocking connection together constitute the second side connection portion of the combined body 1111.

[0089] In some embodiments of the present invention, not shown, the outer layer of the reserved steel bars 1111-1-1 of the roof truss is also wrapped with a reinforcing steel pipe, and the reserved steel bars 1111-1-1 of the roof truss are welded to the reinforcing steel pipe, which can increase the shear resistance of the structure at the connection.

[0090] In this embodiment, refer to Figure 3-6 , 11-15, the corbel column module 12 is configured as a reinforced concrete structure, and the corbel column module 12 includes a first side corbel column 121 and a second side corbel column 122, the top end of the first side corbel column 121 is connected to the first side connection part by a combination of chiming and concrete cast-in-place, and the top end of the second side corbel column 122 is connected to the second side connection part by a combination of chiming and expansion joint docking.

[0091] Please refer to Figure 11-13 In some embodiments of the present invention, the first side corbel column 121 includes a first side corbel column body 1211, and the top of the first side corbel column body 1211 has a first reserved groove 1211-1 and corbel column reserved steel bars; the corbel column reserved steel bars are connected with the roof truss reserved steel bars 1111-1-1 of the upper chord 1111-1 to form a cast-in-place section structure 141, and the first reserved groove 1211-1 is configured to support and embed the first end of the lower chord 1111-2 and the first side vertical rod 1111-3 from the bottom and the side.

[0092] Please refer to Figure 14-15In some embodiments of the present invention, the second side corbel column 122 includes a second side corbel column body 1221, and the top of the second side corbel column body 1221 has a second reserved groove 1221-1 and a first expansion joint steel 1221-2; the first expansion joint steel 1221-2 and the second expansion joint steel 1111-1-2 of the upper chord 1111-1 are symmetrically arranged at intervals to form an expansion joint structure 142, and the second reserved groove 1221-1 is configured to support and embed the second end of the lower chord 1111-2 and the second side vertical rod 1111-3 from the bottom and side.

[0093] The first reserved groove 1211-1 and the second reserved groove 1221-1 are respectively arranged on the opposite sides of the first side corbel column 121 and the second side corbel column 122. The shapes and sizes of the first reserved groove 1211-1 and the second reserved groove 1221-1 match the corresponding ends of the lower chord 1111-2, so that the lower end of the combined body 1111 of the roof truss body 111 is embedded in the first reserved groove 1211-1 or the second reserved groove 1221-1. In specific implementation, the lower end is a right angle portion with two directions. Therefore, the shape of the first reserved groove 1211-1 and the second reserved groove 1221-1 are both L-shaped, which is connected by a lower side groove and an upper side groove.

[0094] Please refer to Figure 4 In some embodiments of the present invention, the shapes of the second expansion joint steel 1111-1-2 and the first expansion joint steel 1221-2 are constructed as a mirror-symmetrical F shape, and the two form an F-type butt-jointed expansion joint structure 142; the second expansion joint steel 1111-1-2 and the first expansion joint steel 1221-2 are also connected in the middle by an elastic rubber strip 1111-1-3.

[0095] Specifically, the material of the elastic rubber strip 1111-1-3 includes at least one of nitrile rubber, polyurethane rubber, chloroprene rubber, and silicone rubber. Preferably, the elastic rubber strip 1111-1-3 is made of nitrile rubber.

[0096] Please refer to Figure 7 , Fig.12 and Fig.15 In some embodiments of the present invention, a first arc structure is formed below the first connection portion between the first end of the lower chord 1111-2 and the first reserved groove 1211-1, and the first arc structure includes a first inner arc 1211-1-1 formed in the first reserved groove 1211-1 and a first outer arc 1111-2-3 formed at the first end of the lower chord 1111-2; a first reinforcing steel plate 1111-2-5 is also wrapped below and on the side of the first connection portion;

[0097] A second arc-shaped structure is present below the second connection portion between the second end of the lower chord 1111-2 and the second reserved groove 1221-1, and the second arc-shaped structure includes a second inner arc 1211-2-1 formed in the second reserved groove 1221-1 and a second outer arc 1111-2-4 formed at the second end of the lower chord 1111-2; a second reinforcing steel plate 1111-2-6 is also wrapped below and on the sides of the second connection portion.

[0098] Because the reinforcing steel plate is wrapped around the two ends of the lower chord 1111-2, the reinforcing steel plate also presents a wrapped arc structure based on the first arc structure and the second arc structure. The arc design can avoid stress concentration during use. The reinforcing steel plate setting can protect the connection between the lower chord 1111-2 and the corbel column to avoid structural damage caused by friction.

[0099] In this embodiment, refer to Figure 3 , Figure 5 , Figure 6 The extracorporeal prestressing adjustment module 13 is configured to be arranged parallel to the length direction of the roof truss body 111, and its two ends respectively penetrate the first interlocking connection between the first side corbel column 121 and the first side connecting part and the second interlocking connection between the second side corbel column 122 and the second side connecting part, and at the same time, the two ends are respectively anchored to the outer sides of the first side corbel column 121 and the second side corbel column 122.

[0100] Please refer to Figure 3 , Figure 5 , Fig. 9 , Fig.10 In some embodiments of the present invention, the external prestressing force regulating module 13 includes external prestressing force steel strands 131 symmetrically arranged on both sides of the lower chord 1111-2, and the external prestressing force steel strands 131 are parallel to the lower chord 1111-2;

[0101] Two first side prestressed tendon anchoring sections 1111-2-1 and two second side prestressed tendon anchoring sections 1111-2-2 of an integral structure are symmetrically arranged on both sides of the two ends of the lower chord 1111-2. Specifically, the first side prestressed tendon anchoring section 1111-2-1 and the second side prestressed tendon anchoring section 1111-2-2 can be prefabricated as an integral whole with the roof truss body 111 and cast in concrete. The length and width of the first side prestressed tendon anchoring section 1111-2-1 and the second side prestressed tendon anchoring section 1111-2-2 are They are respectively matched with the sizes of the first reserved groove 1211-1 and the second reserved groove 1221-1. For example, the lengths of the four prestressed tendon anchoring sections are set according to the lengths of the grooves on the lower side of the corbel column, so that the lengths of the anchoring sections just do not exceed the corbel column; the first side prestressed tendon anchoring section 1111-2-1 and the second side prestressed tendon anchoring section 1111-2-2 are respectively reserved with the first prestressed steel strand pipe 1111-2-1-1 and the second prestressed steel strand pipe 1111-2-2-1 for the external prestressed steel strand 131 to pass through.

[0102] The first side corbel column body 1211 and the second side corbel column body 1221 are respectively provided with a first prestressed tendon pipe and a second prestressed tendon pipe 1221-3 located in the first reserved groove 1211-1 and the second reserved groove 1221-1;

[0103] The two ends of the external prestressed steel strand 131 respectively pass through the first prestressed steel strand pipe 1111-2-1-1 and the first prestressed tendon pipe and the second prestressed steel strand pipe 1111-2-2-1 and the second prestressed tendon pipe 1221-3 in sequence, and after the tensioning is completed, the first anchor end 1311 and the second anchor end 1312 are respectively arranged on the outer sides of the first side corbel column body 1211 and the second side corbel column body 1221.

[0104] like Figure 1 and Figure 2 As shown, the embodiment of the present invention further provides a steel-concrete composite roof truss system 100 based on external prestressing, comprising any of the above-mentioned steel-concrete composite roof truss units 10 and a longitudinal limit unit 20. The longitudinal limit unit 20 is used to connect to two adjacent steel-concrete composite roof truss units 10 to limit the longitudinal displacement of the roof truss unit and increase the integrity of the roof truss system.

[0105] In this embodiment, the longitudinal limiting unit 20 includes at least one longitudinal limiting steel pipe 21, and both ends of each longitudinal limiting steel pipe 21 are respectively anchored on the upper chords 1111-1 of two adjacent steel-concrete composite roof truss units 10. When the number of longitudinal limiting steel pipes 21 is set to multiple, the longitudinal limiting steel pipes 21 are arranged at equal intervals. When the number of longitudinal limiting steel pipes 21 is set to one, its two ends are respectively connected to the midpoints of the upper chords 1111-1 of the two steel-concrete composite roof truss units 10.

[0106] like Fig.16 As shown, the embodiment of the present invention further provides a construction method of a steel-concrete composite roof truss system 100 based on external prestressing, comprising the following steps:

[0107] 1) Pile foundation construction:

[0108] The foundation is laid out and the foundation pit is excavated according to the construction drawings. After the foundation pit excavation is completed, the pile foundation and the pedestal are constructed and maintained.

[0109] 2) Casting of corbel columns:

[0110] After the pile foundation construction is completed and reaches the preset strength requirement, the corbel column module 12 is cast, and at the same time, the first reserved groove 1211-1, the corbel column reserved steel bar, the second reserved groove 1221-1, the reserved prestressed steel bar pipe and the first expansion joint steel 1221-2 are constructed;

[0111] More specifically, after the pile foundation construction is completed and reaches the preset strength requirements, the column reinforcement is tied and the formwork is built first. After the formwork is built, the corbel column module 12 is cast, and a groove is reserved on the side of the corbel column. Prestressed tendon pipes are reserved in the groove, and reserved reinforcement for the corbel column is reserved directly above the left corbel column. The first expansion joint steel 1221-2 is installed above the right corbel column.

[0112] 3) On-site prefabricated roof trusses:

[0113] The prefabricated roof truss module 11 is manufactured according to the design drawings and the reserved groove size of the corbel column module 12; and in the prefabrication process, the roof truss reserved steel bars 1111-1-1 and the second expansion joint steel 1111-1-2 are respectively arranged at both ends of the upper chord 1111-1, and the prestressed steel anchoring sections are arranged at both ends of the lower chord 1111-2, and the external prestressed steel strand 131 pipeline is reserved;

[0114] More specifically, the roof truss is prefabricated according to the design drawings and the size of the reserved groove on the side of the corbel; wherein, a roof truss reserved steel bar 1111-1-1 is arranged at the left end of the upper chord 1111-1 of the roof truss body 111, and a second expansion joint steel 1111-1-2 is installed at the right end of the upper chord 1111-1, the supporting web 1112 of the roof truss body 111 is supported by steel pipe material, prestressed tendon anchoring sections are arranged on both sides and both ends of the lower chord 1111-2, and a pipeline for external prestressed steel strands 131 is reserved.

[0115] 4) Hoisting the roof truss:

[0116] A crane is used on site to butt the prefabricated roof truss module 11 and the corbel column module 12 together;

[0117] More specifically, a crane is used on site to turn over, straighten and hoist the prefabricated roof truss module 11; before hoisting, a layer of resin oil is applied to the reserved groove of the corbel column to reduce structural damage caused by friction between the surface concrete during the hoisting process; during hoisting, the hoisting height of the prefabricated roof truss module 11 is higher than that of the corbel column module 12, and a total station can be used to observe the upper side groove of the corbel column, and the crane is directed to dock the prestressed tendon anchoring section on the lower chord 1111-2 with the reserved groove of the corbel column. After docking, the roof truss body 111 is slowly lowered vertically along the groove;

[0118] 5) Tensioning external prestressing:

[0119] After the prefabricated roof truss module 11 is hoisted, the external prestressing adjustment module 13 is installed to tension the external prestressing of the lower chord 1111-2, and the anchor end is set after the tensioning is completed;

[0120] More specifically, after the prefabricated roof truss is hoisted, external prestressed steel strands 131 are installed on both sides of the lower chord 1111-2. The external prestressed steel strands 131 pass through the prestressed tendon pipes in the grooves of the corbels on both sides and the prestressed tendon anchoring sections at both ends of the lower chord 1111-2. After the external prestressed steel strands 131 are installed, the external prestress of the lower chord 1111-2 is tensioned. After the tensioning is completed, anchoring ends are set on the outside of the corbels on both sides.

[0121] After the prefabricated roof truss is hoisted, the external prestressed steel strands 131 are tensioned as a whole, and the external prestressed steel strands 131 are tensioned and anchored on the outside of the corbel column, which mainly plays a role in increasing the integrity of the roof truss and the corbel column.

[0122] It should be noted that the anchoring end here refers to the fixation of the external prestressed steel strand 131 after tensioning by selective devices such as anchor plates and bolts, but there is no limitation on the specific devices and tools used, as long as the tensioning and fixation of the external prestressed steel strand 131 can be achieved.

[0123] Furthermore, after the loss of prestress is detected by the pressure sensor arranged at the anchoring end, one end of the external prestressed steel strand 131 on the outside of the right-end corbel column can be tensioned using a tensioning jack; the anchoring end on the outside of the right-end corbel is removed, the external prestressed steel strand 131 is passed through the jack, and the clip is installed, and then tensioning is performed, and it can be determined by the reading of the pressure gauge whether the prestress is readjusted to the design value.

[0124] It should also be noted that after long-term use, if the external prestressed steel strand 131 is damaged and difficult to adjust to the design value, the anchor end on the outside of the corbel column and the external prestressed steel strand 131 can be removed, and a new external prestressed steel strand 131 can be reinstalled and tensioned and anchored.

[0125] 6) Cast-in-place section construction and expansion joint installation: After the prestressing of the lower chord 1111-2 is completed, the cast-in-place section structure 141 and the expansion joint structure 142 are constructed at both ends of the roof truss body 111;

[0126] More specifically, after the prefabricated roof truss is fitted with the reserved groove of the corbel column, the steel bars are tied and the formwork is built above the left corbel column. After the formwork is built, concrete is poured in situ to form a cast-in-situ section structure 141; the second expansion joint steel 1111-1-2 on the prefabricated roof truss and the first expansion joint steel 1221-2 above the corbel column form an F-type docking expansion joint structure 142, and an elastic rubber strip 1111-1-3 is used to connect the expansion joint above the right corbel column and the right end of the upper chord 1111-1.

[0127] 7) Install longitudinal support:

[0128] After the two adjacent steel-concrete composite roof truss units 10 are installed in sequence according to step 1) to step 6), the longitudinal limit unit 20 is installed between the two. Specifically, the two ends of the longitudinal limit steel pipe 21 are anchored and connected to the upper chord 1111-1 by high-strength bolts.

[0129] In summary, the steel-concrete composite roof truss unit, system and construction method based on external prestressing provided by the embodiments of the present invention can achieve the following significant advantages:

[0130] 1. The embodiments of the present invention are based on an externally prestressed steel-concrete composite roof truss unit and system, and adopt a consolidation method of cast-in-place steel bars and concrete combined with expansion joints, thereby avoiding the problem of cracks between the prefabricated roof truss and the corbel column due to consolidation under the action of temperature stress, thereby increasing the reliability of the structure.

[0131] 2. The embodiment of the present invention is based on an externally prestressed steel-concrete composite roof truss unit and system, and is provided with an external prestressing regulating module 13. By applying external prestressing, it is convenient to monitor the reserve amount of the roof truss prestress, and the prestressing can be reapplied and reinforced when the roof truss prestressing is lost.

[0132] 3. The present invention is based on an externally prestressed steel-concrete composite roof truss unit and system, which fully utilizes the advantages of the steel-concrete composite structural system to make the prefabricated roof truss structure green, environmentally friendly and refined. At the same time, steel pipes are used as supporting materials for the supporting webs 1112 to ensure the bearing capacity of the prefabricated roof truss.

[0133] 4. The present invention is based on an externally prestressed steel-concrete composite roof truss unit, system and construction method, which can be effectively applied to the construction of large-span prestressed roof truss structures of factories and granaries, as well as the construction of similar beam-column structures. It has a wide range of applications and can meet the force requirements at the same time. The overall structure is stable and reliable.

[0134] 5. The construction method of the externally prestressed steel-concrete composite roof truss system 100 of the present invention has the characteristics of simple steps, reasonable design, simple construction, and easy control of construction quality. It can simply and quickly complete the installation construction process of the roof truss system, and the construction process is safe and reliable.

[0135] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0136] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0137] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0138] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any simple modifications and equivalent changes made to the above embodiments based on the technical essence of the present invention fall within the protection scope of the present invention.

Claims

1. A steel-concrete composite roof truss unit based on external prestressing, characterized in that: include: The prefabricated roof truss module is configured as a steel-concrete composite structure, and the prefabricated roof truss module includes a roof truss body, and the two ends of the roof truss body in the length direction are respectively formed with a first side connection part and a second side connection part; A corbel column module is configured as a reinforced concrete structure, the corbel column module comprises a first side corbel column and a second side corbel column, the top end of the first side corbel column is connected to the first side connection portion by a combination of chiming and concrete casting, and the top end of the second side corbel column is connected to the second side connection portion by a combination of chiming and expansion joint docking; The extracorporeal prestressed stress adjustment module is configured to be arranged parallel to the length direction of the roof truss body and the two ends of which respectively penetrate the first interlocking connection between the first side corbel column and the first side connecting part and the second interlocking connection between the second side corbel column and the second side connecting part, and the two ends are respectively anchored to the outer sides of the first side corbel column and the second side corbel column.

2. The steel-concrete composite roof truss unit based on external prestressing according to claim 1 is characterized in that: The roof truss body comprises a combined body of an upper chord bar, a lower chord bar and vertical bars of a concrete structure and a supporting web bar of a steel pipe structure.

3. The steel-concrete composite roof truss unit based on external prestressing according to claim 2 is characterized in that: The first side corbel column comprises a first side corbel column body, and the top end of the first side corbel column body has a first reserved groove and a corbel column reserved steel bar; The first side connection portion includes a roof truss reserved steel bar formed on the upper part of the first end of the upper chord, and the roof truss reserved steel bar is used to connect with the corbel reserved steel bar to form a cast-in-place section structure. At the same time, the first reserved groove is configured to support and embed the first end of the lower chord and the first side vertical rod from the bottom and the side.

4. The steel-concrete composite roof truss unit based on external prestressing according to claim 3 is characterized in that: The outer layer of the reserved steel bars for the roof truss is also wrapped with a reinforcing steel pipe, and the reserved steel bars for the roof truss are welded to the reinforcing steel pipe.

5. The steel-concrete composite roof truss unit based on external prestressing according to claim 3 is characterized in that: The second side corbel column comprises a second side corbel column body, and the top end of the second side corbel column body has a second reserved groove and a first expansion joint steel; The second side connection portion includes a second expansion joint steel formed on the upper part of the second end of the upper chord, and the second expansion joint steel is used to be arranged symmetrically with the first expansion joint steel to form an expansion joint structure. At the same time, the second reserved groove is configured to support and embed the second end of the lower chord and the second side vertical rod from the bottom and the side.

6. The steel-concrete composite roof truss unit based on external prestressing according to claim 5 is characterized in that: The second expansion joint steel and the first expansion joint steel are constructed in a mirror-symmetrical F shape, and the two form an F-shaped butt-jointed expansion joint structure; the second expansion joint steel and the first expansion joint steel are also connected in the middle by an elastic rubber strip.

7. The steel-concrete composite roof truss unit based on external prestressing according to claim 5 is characterized in that: The external prestressing force adjustment module comprises external prestressing steel strands symmetrically arranged on both sides of the lower chord, and the external prestressing steel strands are parallel to the lower chord; Two first-side prestressed tendon anchoring sections and two second-side prestressed tendon anchoring sections of an integrated structure are symmetrically arranged on both sides of the two ends of the lower chord, and the first-side prestressed tendon anchoring sections and the second-side prestressed tendon anchoring sections are respectively reserved with a first prestressed steel strand pipe and a second prestressed steel strand pipe; The first side corbel column body and the second side corbel column body are respectively provided with a first prestressed tendon pipe and a second prestressed tendon pipe located in the first reserved groove and the second reserved groove; The two ends of the external prestressed steel strand respectively pass through the first prestressed steel strand pipeline and the first prestressed tendon pipeline and the second prestressed steel strand pipeline and the second prestressed tendon pipeline in sequence, and after the tensioning is completed, the first anchor end and the second anchor end are respectively arranged on the outer side of the first side corbel column body and the second side corbel column body.

8. The steel-concrete composite roof truss unit based on external prestressing according to claim 5, 6 or 7, characterized in that: A first arc-shaped structure is formed below the first connection portion between the first end of the lower chord and the first reserved groove, wherein the first arc-shaped structure includes a first inner arc formed in the first reserved groove and a first outer arc formed at the first end of the lower chord; a first reinforcing steel plate is also wrapped below and on the side of the first connection portion; A second arc-shaped structure is present below the second connection portion between the second end of the lower chord and the second reserved groove, and the second arc-shaped structure includes a second inner arc formed in the second reserved groove and a second outer arc formed at the second end of the lower chord; a second reinforcing steel plate is also wrapped below and on the sides of the second connection portion.

9. A steel-concrete composite roof truss system based on external prestressing, characterized in that: include: A steel-concrete composite roof truss unit as described in any one of claims 1 to 8; A longitudinal limiting unit is used to connect to two adjacent steel-concrete composite roof truss units. The longitudinal limiting unit includes at least one longitudinal limiting steel pipe. A plurality of the longitudinal limiting steel pipes are arranged at equal intervals. Both ends of each longitudinal limiting steel pipe are respectively anchored on the upper chords of the two adjacent steel-concrete composite roof truss units.

10. A construction method based on external prestressed steel-concrete composite roof truss system as claimed in claim 9, characterized in that: The following steps are involved: 1) Pile foundation construction; 2) Casting of corbel columns: After the pile foundation construction is completed and reaches the preset strength requirement, the corbel column module is cast, and at the same time, the first reserved groove, the corbel column reserved steel bar, the second reserved groove, the reserved prestressed steel bar pipe and the first expansion joint steel are constructed; 3) On-site prefabricated roof trusses: The prefabricated roof truss module is manufactured according to the design drawings and the reserved groove size of the corbel column module; and during the prefabrication process, the roof truss reserved steel bars and the second expansion joint steel are respectively set at both ends of the upper chord, and the prestressed tendon anchoring sections are set at both ends of the lower chord, and the external prestressed steel strand pipe is reserved; 4) Hoisting the roof truss: A crane is used on site to connect the prefabricated roof truss module with the corbel column module; 5) Tensioning external prestressing: After the prefabricated roof truss module is hoisted, the external prestressing adjustment module is installed to tension the external prestressing of the lower chord. After the tensioning is completed, the anchor end is set; 6) Cast-in-place section construction and expansion joint installation: After the prestressing of the lower chord is completed, the cast-in-place section structure and expansion joint structure are constructed at both ends of the roof truss; 7) Install longitudinal support: After the two adjacent steel-concrete composite roof truss units are installed in sequence according to step 1) to step 6), a longitudinal limit unit is installed between the two.

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