Steel-concrete composite roof truss unit, system and construction method based on in-vitro prestress

Abstract

A steel-concrete composite roof truss unit, system and construction method based on external prestress. The steel-concrete composite roof truss unit comprises a prefabricated roof truss module, a corbel column module and an external prestress adjusting module. The prefabricated roof truss module of the steel-concrete composite structure comprises a roof truss body, and the length direction of the roof truss body is provided with a first side connecting part and a second side connecting part at both ends respectively. The corbel column module of the reinforced concrete structure comprises a first side corbel column and a second side corbel column, the top end of the first side corbel column is connected with the first side connecting part through the combination of embedding and concrete cast-in-place, and the top end of the second side corbel column is connected with the second side connecting part through the combination of embedding and expansion joint butt joint. The external prestress adjusting module is arranged parallel to the length direction of the roof truss body and penetrates the first embedded connecting part between the first side corbel column and the first side connecting part and the second embedded connecting part between the second side corbel column and the second side connecting part at both ends respectively, and the both ends are anchored outside the first side corbel column and the second side corbel column respectively. The present application aims to solve the problems of large span prestressed roof truss, such as large weight, difficult to monitor prestress loss, prone to cracks at the connection with the corbel column and the like.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to steel-concrete composite roof truss units, systems and construction methods based on external prestressing. Background Technology

[0002] As is well known, in the construction of large factories and grain warehouses in my country, prestressed structural systems are usually adopted due to the large span of the roof trusses. Prestressed roof truss structures can not only effectively improve the load-bearing capacity of grain warehouses when subjected to snow loads, but also improve the construction accuracy of the roof trusses, reduce costs, and significantly shorten the construction period by prefabricating them in advance.

[0003] Currently, prestressed roof trusses are usually made of concrete, with prestressing tensioned on the lower chord of the truss. This has problems such as heavy self-weight, difficulty in hoisting, and difficulty in monitoring the loss of prestress during use.

[0004] Existing prestressed concrete roof trusses typically connect to the corbel columns by welding the embedded reinforcing bars in both the corbel columns and the roof truss, or by bolting the pre-drilled bolt holes in the corbel columns and the roof truss. Because this method of connection generates significant bending moments at the connection point between the roof truss and the concrete columns during use, it is highly susceptible to cracking under snow loads and temperature stresses. Furthermore, it leads to reduced structural strength, shortened structural lifespan, and increased safety hazards. Summary of the Invention

[0005] The present invention aims to overcome, at least to some extent, the aforementioned shortcomings in related technologies. To this end, the present invention proposes a steel-concrete composite roof truss unit, system, and construction method based on external prestressing. This design is reasonable, construction is simple, and performance is good. It effectively solves problems such as the heavy self-weight of existing large-span prestressed roof trusses, difficulty in monitoring prestress loss, and susceptibility to cracking at the connection with corbel columns.

[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. The prefabricated roof truss module includes a roof truss body, and a first side connection and a second side connection are formed at both ends of the length direction of the roof truss body, respectively.

[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 of the first side corbel column is connected to the first side connection part by a combination of fitting and cast-in-place concrete. The top of the second side corbel column is connected to the second side connection part by a combination of fitting and expansion joint connection.

[0009] The external prestressing adjustment module is configured to be parallel to the length direction of the roof truss body and its two ends pass through the first fitting connection between the first side bracket column and the first side connecting part and the second fitting connection between the second side bracket column and the second side connecting part, respectively. At the same time, the two ends are respectively anchored to the outside of the first side bracket column and the second side bracket column.

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

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

[0012] The first side connection 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 reserved steel bar of the corbel column to form a cast-in-place section structure. At the same time, the first reserved groove is configured to support and fit the first end of the lower chord and the first side vertical bar from the bottom and the side.

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

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

[0015] The second side connection includes a second expansion joint steel formed on the upper part of the second end of the upper chord. The second expansion joint steel is used to form an expansion joint structure by being symmetrically arranged with the first expansion joint steel at intervals. At the same time, the second reserved groove is configured to support and fit the second end of the lower chord and the second side vertical bar 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 configured to be mirror-symmetrical F-shaped, forming an F-shaped butt-joint expansion joint structure; the second expansion joint steel and the first expansion joint steel are also connected by an elastic rubber strip in the middle.

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

[0018] The two ends of the lower chord are respectively provided with two first-side prestressed tendon anchorage sections and two second-side prestressed tendon anchorage sections with an integral structure. The first-side prestressed tendon anchorage section and the second-side prestressed tendon anchorage section are respectively reserved with first prestressed steel strand pipe and second prestressed steel strand pipe.

[0019] The first and second side bracket columns are respectively provided with a first prestressed tendon duct and a second prestressed tendon duct located in the first reserved groove and the second reserved groove.

[0020] The two ends of the external prestressed steel strand pass through the first prestressed steel strand duct, the first prestressed tendon duct, the second prestressed steel strand duct, and the second prestressed tendon duct in sequence. After tensioning, the two ends are respectively provided with the first anchor end and the second anchor end on the outside of the first side bracket column body and the second side bracket column body.

[0021] According to one embodiment of the present invention, the lower end of the lower chord and the first connection portion of the first reserved groove have a first arc-shaped structure below them. The first arc-shaped structure includes a first inner arc formed in the first reserved groove and a first outer arc formed in the first end of the lower chord. The lower part and the side of the first connection portion are also wrapped with a first reinforcing steel plate.

[0022] The second end of the lower chord and the second connection part of the second reserved groove both have a second arc-shaped structure below them. The second arc-shaped structure includes a second inner arc formed in the second reserved groove and a second outer arc formed in the second end of the lower chord. The lower part and the side of the second connection part are also wrapped with a second reinforcing steel plate.

[0023] According to the present invention, a steel-concrete composite roof truss system based on external prestressing includes:

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

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

[0026] A construction method for a steel-concrete composite roof truss system based on external prestressing according to the present invention includes 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 requirements, the corbel column module is poured, and at the same time the first reserved groove, the corbel column reserved steel bar, the second reserved groove, the reserved prestressed tendon pipe and the first expansion joint steel are constructed.

[0030] 3) On-site prefabrication of roof trusses:

[0031] The prefabricated roof truss modules are manufactured according to the design drawings and the reserved groove dimensions of the corbel column modules; 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 anchorage sections are set at both ends of the lower chord and the external prestressed steel strand pipes are reserved.

[0032] 4) Hoisting the roof truss:

[0033] On-site, a crane was used to connect the prefabricated roof truss modules to the corbel column modules;

[0034] 5) External prestressing:

[0035] After the precast roof truss modules are hoisted, the external prestressing adjustment module is installed, the external prestress of the lower chord is tensioned, and the anchoring end is set after the tensioning is completed.

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

[0037] 7) Install longitudinal supports:

[0038] After two adjacent steel-concrete composite roof truss units are installed sequentially according to steps 1) to 6), a longitudinal limiting unit is installed between them.

[0039] According to the steel-concrete composite roof truss unit, system, and construction method based on external prestressing of the present invention, the pre-reserved reinforcing bars and expansion joint structure that are matched between the corbel column module and the precast roof truss module, and the external prestressing adjustment module set at the connection, enable convenient monitoring of the prestress reserve of the roof truss by applying external prestressing. This facilitates timely re-application of prestressing and reinforcement after loss of prestress is detected.

[0040] Therefore, the present invention is reasonably designed, easy to construct, and has good performance. It can effectively solve the problems of existing prestressed concrete roof trusses, such as heavy self-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 easy cracking under temperature stress.

[0041] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments.

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

[0044] Figure 2 This 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 This is a front view structural schematic diagram 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 A magnified schematic diagram of the structure at point A in the middle.

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

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

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

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

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

[0053] Figure 11 This is a three-dimensional 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.

[0054] Figure 12 This is a front view 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.

[0055] Figure 13 This is a side view 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] Figure 14This is a three-dimensional structural schematic diagram 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] Figure 15 This is a front view structural schematic diagram 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] Figure 16 This is a flowchart illustrating some embodiments of the construction method of the steel-concrete composite roof truss system based on external prestressing of the present invention.

[0059] Meaning of the labels in the attached diagram:

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

[0061] 10-Steel-Concrete Composite Roof Truss Unit;

[0062] 11-Prefabricated roof truss module;

[0063] 111 - Main roof truss;

[0064] 1111 - Combined main body;

[0065] 1111-1-Top chord; 1111-1-1-Roof truss reserved reinforcement; 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 duct; 1111-2-2-Second side prestressed tendon anchorage section; 1111-2-2-1-Second prestressed steel strand duct; 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 rod;

[0068] 1112 - Supporting web member;

[0069] 12-Corner Column Module;

[0070] 121 - First lateral support column;

[0071] 1211-First side corbel column body; 1211-1-First reserved groove; 1211-1-First inner arc; 1211-2-Corbel column reserved reinforcing bar; 1211-3-First prestressed tendon duct;

[0072] 122 - Second side corbel;

[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 duct;

[0074] 13-External prestressing adjustment module;

[0075] 131 - Externally prestressed steel strand;

[0076] 1311 - First anchoring end;

[0077] 1312 - Second anchoring end;

[0078] 141 - Cast-in-place section structure;

[0079] 142 - Expansion joint structure;

[0080] 20 - Longitudinal limiting unit;

[0081] 21-Longitudinal limiting steel pipe. Detailed Implementation

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

[0083] The following is based on Figures 1-16 The present invention provides a detailed description of the steel-concrete composite roof truss unit, system, and construction method based on external prestressing.

[0084] like Figures 3 to 15 As shown, this embodiment of the 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, and a first side connection portion and a second side connection portion are formed at both ends of the roof truss body 111 along its length.

[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 a concrete upper chord 1111-1, a lower chord 1111-2, and a vertical member 1111-3, and a supporting web member 1112 of a steel pipe structure.

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

[0088] Furthermore, the first side connection includes a roof truss reserved steel bar 1111-1-1 formed on the upper part of the first end of the upper chord 1111-1 and a first fitting connection with the corbel column module 12. The second side connection includes a second expansion joint steel bar 1111-1-2 formed on the upper part of the second end of the upper chord 1111-1 and a second fitting connection with the corbel column module 12. Here, the roof truss reserved steel bar 1111-1-1 and the second expansion joint steel bar 1111-1-2 serve as the cast-in-place connection and the expansion joint docking point, respectively, connecting with the corbel column module 12. The cast-in-place connection and the first fitting connection together constitute the first side connection of the combined body 1111. Similarly, the expansion joint docking point and the second fitting connection together constitute the second side connection of the combined body 1111.

[0089] In some embodiments of the present invention (not shown), the outer layer of the pre-reserved steel bar 1111-1-1 of the roof truss is also wrapped with a reinforcing steel pipe. The pre-reserved steel bar 1111-1-1 of the roof truss is 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. The corbel column module 12 includes a first side corbel column 121 and a second side corbel column 122. The top of the first side corbel column 121 is connected to the first side connecting part by a combination of fitting and cast-in-place concrete. The top of the second side corbel column 122 is connected to the second side connecting part by a combination of fitting and expansion joint connection.

[0091] Please refer to Figure 11-13 In some embodiments of the present invention, the first side corbel 121 includes a first side corbel body 1211, the top of the first side corbel body 1211 having a first reserved groove 1211-1 and a corbel reserved reinforcing bar; the corbel reserved reinforcing bar is connected to the roof truss reserved reinforcing bar 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 fit the first end of the lower chord 1111-2 and the first side vertical bar 1111-3 from the bottom and side.

[0092] Please refer to Figure 14-15In some embodiments of the present invention, the second side bracket post 122 includes a second side bracket post body 1221. The top end of the second side bracket post 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. At the same time, the second reserved groove 1221-1 is configured to support and fit the second end of the lower chord 1111-2 and the second side vertical bar 1111-3 from the bottom and the side.

[0093] The first reserved groove 1211-1 and the second reserved groove 1221-1 are respectively provided on the opposite side of the first side bracket column 121 and the second side bracket column 122. The shape and size of the first reserved groove 1211-1 and the second reserved groove 1221-1 are matched with the corresponding end of the lower chord 1111-2, so that the lower end of the combined body 1111 of the roof truss body 111 is fitted into the first reserved groove 1211-1 or the second reserved groove 1221-1. In specific implementation, the lower end is a right angle part with two directions. Therefore, the shape of the first reserved groove 1211-1 and the second reserved groove 1221-1 is L-shaped and is formed by a lower side groove and an upper side groove connected together.

[0094] Please refer to Figure 4 In some embodiments of the present invention, the second expansion joint steel 1111-1-2 and the first expansion joint steel 1221-2 are configured as mirror-symmetrical F-shaped structures, forming an F-shaped butt-joint expansion joint structure 142; the second expansion joint steel 1111-1-2 and the first expansion joint steel 1221-2 are also connected by an elastic rubber strip 1111-1-3 in the middle.

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

[0096] Please refer to Figure 7 , Figure 12 and Figure 15 In some embodiments of the present invention, the first end of the lower chord 1111-2 and the first connection portion of the first reserved groove 1211-1 form a first arc-shaped structure below the first connection portion. The first arc-shaped 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. The lower part and the side of the first connection portion are also covered with a first reinforcing steel plate 1111-2-5.

[0097] The second end of the lower chord 1111-2 and the lower part of the second connection of the second reserved groove 1221-1 both have a second arc-shaped structure. 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. The lower part and the side of the second connection are also wrapped with a second reinforcing steel plate 1111-2-6.

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

[0099] In this embodiment, refer to Figure 3 , Figure 5 , Figure 6 The external prestress adjustment module 13 is configured to be parallel to the length direction of the roof truss body 111 and its two ends pass through the first fitting connection between the first side bracket column 121 and the first side connecting part and the second fitting connection between the second side bracket column 122 and the second side connecting part, respectively. At the same time, the two ends are respectively anchored to the outside of the first side bracket column 121 and the second side bracket column 122.

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

[0101] The lower chord 1111-2 has two integrally formed first-side prestressed tendon anchorage sections 1111-2-1 and two second-side prestressed tendon anchorage sections 1111-2-2 on both sides. Specifically, the first-side prestressed tendon anchorage sections 1111-2-1 and 1111-2-2 can be prefabricated integrally with the roof truss main body 111 and cast in concrete. The length and width dimensions of the first-side prestressed tendon anchorage sections 1111-2-1 and 1111-2-2 are as follows: The dimensions of the four prestressed tendon anchorage sections are respectively matched with the dimensions of the first reserved groove 1211-1 and the second reserved groove 1221-1. For example, the length of the four prestressed tendon anchorage sections is set according to the length of the groove on the lower side of the corbel column, so that the length of the anchorage section just does not exceed the corbel column. The first prestressed tendon anchorage section 1111-2-1 and the second prestressed tendon anchorage section 1111-2-2 are respectively reserved inside 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 bracket column body 1211 and the second side bracket 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 pass through the first prestressed steel strand duct 1111-2-1-1 and the first prestressed tendon duct, as well as the second prestressed steel strand duct 1111-2-2-1 and the second prestressed tendon duct 1221-3 in sequence. After tensioning, the two ends are respectively provided with the first anchoring end 1311 and the second anchoring end 1312 on the outside of the first side bracket column body 1211 and the second side bracket column body 1221.

[0104] like Figure 1 and Figure 2 As shown, this embodiment of the invention also provides a steel-concrete composite roof truss system 100 based on external prestressing, including any of the steel-concrete composite roof truss units 10 as described above and a longitudinal limiting unit 20. The longitudinal limiting unit 20 is used to connect two adjacent steel-concrete composite roof truss units 10 to restrict longitudinal displacement of the roof truss units and increase the overall integrity of the roof truss system.

[0105] In this embodiment, the longitudinal limiting unit 20 includes at least one longitudinal limiting steel pipe 21. Both ends of each longitudinal limiting steel pipe 21 are respectively anchored to the upper chord 1111-1 of two adjacent steel-concrete composite roof truss units 10. When there are multiple longitudinal limiting steel pipes 21, they are arranged at equal intervals. When there is only one longitudinal limiting steel pipe 21, both ends are connected to the midpoint of the upper chord 1111-1 of two steel-concrete composite roof truss units 10.

[0106] like Figure 16 As shown, this embodiment of the invention provides a construction method for a steel-concrete composite roof truss system 100 based on external prestressing, including the following steps:

[0107] 1) Pile foundation construction:

[0108] According to the construction drawings, the foundation layout and foundation pit excavation are carried out. After the foundation pit excavation is completed, the pile foundation and pile cap are constructed and maintained.

[0109] 2) Casting of corbel columns:

[0110] After the pile foundation construction is completed and reaches the preset strength requirements, the corbel column module 12 is poured, and the first reserved groove 1211-1, the corbel column reserved steel bar, the second reserved groove 1221-1, the reserved prestressed tendon 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 erected first. After the formwork is erected, the corbel column module 12 is poured, and a groove is reserved on the side of the corbel column. The prestressed tendon pipe is reserved in the groove. The corbel column pre-reserved reinforcement is reserved directly above the left corbel column, and the first expansion joint steel 1221-2 is installed above the right corbel column.

[0112] 3) On-site prefabrication of roof trusses:

[0113] According to the design drawings and the reserved groove size of the corbel column module 12, the prefabricated roof truss module 11 is manufactured; and during the prefabrication process, the roof truss reserved steel bar 1111-1-1 and the second expansion joint steel 1111-1-2 are respectively set at both ends of the upper chord 1111-1, and the prestressed tendon anchorage section is set at both ends of the lower chord 1111-2 and the external prestressed steel strand 131 pipe is reserved.

[0114] More specifically, the roof truss is prefabricated according to the design drawings and the dimensions of the pre-reserved grooves on the side of the corbel column; wherein, a pre-reserved steel bar 1111-1 is set at the left end of the upper chord 1111-1 of the main body of the roof truss 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 members 1112 of the main body of the roof truss 111 are supported by steel pipe materials. Prestressed tendon anchorage sections are set on both sides and both ends of the lower chord 1111-2, and external prestressed steel strand 131 pipes are reserved.

[0115] 4) Hoisting the roof truss:

[0116] On-site, a crane was used to connect the prefabricated roof truss module 11 to the corbel column module 12.

[0117] More specifically, a crane is used on site to turn over, straighten, and hoist the precast roof truss module 11. Before hoisting, a layer of resin oil is brushed onto the reserved groove of the corbel column to reduce structural damage caused by friction between surface concrete during hoisting. During hoisting, the hoisting height of the precast roof truss module 11 should be higher than that of the corbel column module 12. A total station can be used to observe the groove on the upper side of the corbel column, and the crane is directed to align the prestressed tendon anchorage section on the lower chord 1111-2 with the reserved groove of the corbel column. After the alignment is completed, the roof truss main body 111 is slowly lowered vertically along the groove.

[0118] 5) External prestressing:

[0119] After the precast roof truss module 11 is hoisted, the external prestressing adjustment module 13 is installed, the external prestress of the lower chord 1111-2 is tensioned, and the anchoring end is set after the tensioning is completed.

[0120] More specifically, after the precast 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 corbel columns on both sides and the prestressed tendon anchorage 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, anchorage ends are set on the outside of the corbel columns on both sides.

[0121] After the precast roof truss is hoisted, the external prestressed steel strands 131 are tensioned as a whole. The tensioning and anchoring of the external prestressed steel strands 131 are carried out on the outside of the corbel column, which mainly serves to increase the integrity of the roof truss and the corbel column.

[0122] It should be noted that the anchoring end here refers to fixing the externally prestressed steel strand 131 after tensioning by means of anchoring plates, bolts or other selective devices, but there are no restrictions on the specific devices or tools used, as long as they can achieve the tensioning and fixing of the externally prestressed steel strand 131.

[0123] Furthermore, by using a pressure sensor placed at the anchorage end to detect the loss of prestress, a tensioning jack can be used to tension one end of the external prestressed steel strand 131 on the outer side of the right-end corbel column; the anchorage end on the outer side of the right-end corbel can be removed, the external prestressed steel strand 131 can be passed through the jack and a clamp can be installed, and then tensioning can be performed. The reading of the pressure gauge can then be used to determine whether the prestress has been readjusted to the design value.

[0124] It should also be noted that if the external prestressed steel strand 131 is damaged after long-term use and it is difficult to adjust to the design value, the anchoring 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) Construction of cast-in-place section and installation of expansion joint: After the prestressing tension 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 main body 111 respectively.

[0126] More specifically, after the precast roof truss and the reserved groove of the corbel column are fitted together, the steel bars are tied and the formwork is erected above the left corbel column. After the formwork is erected, the concrete is poured in place to form the cast-in-place section structure 141. The second expansion joint steel 1111-1-2 on the precast roof truss and the first expansion joint steel 1221-2 above the corbel column form an F-shaped butt joint expansion joint structure 142. The expansion joint above the right corbel column and the right end of the upper chord 1111-1 is connected using an elastic rubber strip 1111-1-3.

[0127] 7) Install longitudinal supports:

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

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

[0130] 1. The embodiments of the present invention are based on steel-concrete composite roof truss units and systems with external prestressing. They adopt a consolidation method of steel reinforcement + cast-in-place concrete combined with expansion joint butt connection, which avoids the problem of cracks easily generated between the precast roof truss and the corbel column due to temperature stress, and increases the reliability of the structure.

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

[0132] 3. This invention is based on an externally prestressed steel-concrete composite roof truss unit and system. It makes full use of the advantages of the steel-concrete composite structure system, making the prefabricated roof truss structure green, environmentally friendly and refined. At the same time, it uses steel pipes as the supporting material for the web members 1112, which ensures the load-bearing capacity of the prefabricated roof truss.

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

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

[0135] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0136] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0137] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0138] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications and equivalent changes made to the above embodiments based on the technical essence of the present invention shall 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. The prefabricated roof truss module includes a roof truss body, and a first side connection portion and a second side connection portion are formed at both ends of the length direction of the roof truss body, respectively. 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 of the first side corbel column is connected to the first side connecting part by a combination of fitting and cast-in-place concrete. The top of the second side corbel column is connected to the second side connecting part by a combination of fitting and expansion joint connection. The external prestress adjustment module is configured to be parallel to the length direction of the roof truss body and its two ends pass through the first fitting connection between the first side bracket column and the first side connection part and the second fitting connection between the second side bracket column and the second side connection part, respectively. At the same time, the two ends are respectively anchored to the outside of the first side bracket column and the second side bracket column. The main body of the roof truss includes a combination of upper chord, lower chord and vertical members of concrete structure and supporting web members of steel pipe structure; The first side bracket column includes a first side bracket column body, and the top of the first side bracket column body has a first reserved groove and a bracket column reserved steel bar; The first side connection 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 reserved steel bar of the corbel column to form a cast-in-place section structure. At the same time, the first reserved groove is configured to support and fit the first end of the lower chord and the first side vertical bar from the bottom and the side. The second side bracket column includes a second side bracket column body, and the top of the second side bracket column body has a second reserved groove and a first expansion joint steel. The second side connection includes a second expansion joint steel formed on the upper part of the second end of the upper chord. The second expansion joint steel is used to form an expansion joint structure by being symmetrically arranged with the first expansion joint steel at intervals. At the same time, the second reserved groove is configured to support and fit the second end of the lower chord and the second side vertical bar from the bottom and the side.

2. The steel-concrete composite roof truss unit based on external prestressing according to claim 1, characterized in that, The outer layer of the pre-reserved steel bars in the roof truss is also wrapped with a reinforcing steel pipe, and the pre-reserved steel bars in the roof truss are welded to the reinforcing steel pipe.

3. The steel-concrete composite roof truss unit based on external prestressing according to claim 1, characterized in that, The second expansion joint steel and the first expansion joint steel are constructed in a mirror-symmetrical F-shape, forming an F-shaped butt joint expansion joint structure; the second expansion joint steel and the first expansion joint steel are also connected by an elastic rubber strip in the middle.

4. The steel-concrete composite roof truss unit based on external prestressing according to claim 1, characterized in that, The external prestressing adjustment module includes 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. The lower chord has two first-side prestressed tendon anchorage sections and two second-side prestressed tendon anchorage sections with an integral structure on both sides. The first-side prestressed tendon anchorage section and the second-side prestressed tendon anchorage section are respectively reserved with first prestressed steel strand pipe and second prestressed steel strand pipe inside. The first side bracket column body and the second side bracket 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 pass through the first prestressed steel strand duct, the first prestressed tendon duct, the second prestressed steel strand duct, and the second prestressed tendon duct in sequence. After tensioning, the two ends are respectively provided with a first anchoring end and a second anchoring end on the outside of the first side bracket column body and the second side bracket column body.

5. The steel-concrete composite roof truss unit based on external prestressing according to claim 1, 3, or 4, characterized in that, The first end of the lower chord and the first connection part of the first reserved groove form a first arc-shaped structure below the first connection part. The first arc-shaped structure includes a first inner arc formed in the first reserved groove and a first outer arc formed in the first end of the lower chord. The lower part and the side of the first connection part are also wrapped with a first reinforcing steel plate. The second end of the lower chord and the second connection part of the second reserved groove both have a second arc-shaped structure below them. The second arc-shaped structure includes a second inner arc formed in the second reserved groove and a second outer arc formed in the second end of the lower chord. The second connection part is also wrapped with a second reinforcing steel plate below and to the side.

6. A steel-concrete composite roof truss system based on external prestressing, characterized in that, include: The steel-concrete composite roof truss unit as described in claim 4 above; A longitudinal limiting unit is used to connect two adjacent steel-concrete composite roof truss units. The longitudinal limiting unit includes at least one longitudinal limiting steel pipe, and multiple longitudinal limiting steel pipes are arranged at equal intervals. The two ends of each longitudinal limiting steel pipe are respectively anchored to the upper chord of two adjacent steel-concrete composite roof truss units.

7. A construction method for a steel-concrete composite roof truss system based on external prestressing as described in claim 6, characterized in that, Includes the following steps: 1) Pile foundation construction; 2) Casting of corbel columns: After the pile foundation construction is completed and reaches the preset strength requirements, the corbel column module is poured, and at the same time the first reserved groove, the corbel column reserved steel bar, the second reserved groove, the reserved prestressed tendon pipe and the first expansion joint steel are constructed. 3) On-site prefabrication of roof trusses: The prefabricated roof truss modules are manufactured according to the design drawings and the reserved groove dimensions of the corbel column modules; 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 anchorage sections are set at both ends of the lower chord and the external prestressed steel strand pipes are reserved. 4) Hoisting the roof truss: On-site, a crane was used to connect the prefabricated roof truss modules to the corbel column modules; 5) External prestressing: After the precast roof truss modules are hoisted, the external prestressing adjustment module is installed, the external prestress of the lower chord is tensioned, and the anchoring end is set after the tensioning is completed. 6) Construction of cast-in-place section and installation of expansion joints: After the prestressing tension of the lower chord is completed, cast-in-place section structure and expansion joint structure are constructed at both ends of the main roof truss. 7) Install longitudinal supports: After two adjacent steel-concrete composite roof truss units are installed sequentially according to steps 1) to 6), a longitudinal limiting unit is installed between them.

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