Construction method of full assembly type concrete frame connected by overlapping end plates

Abstract

The application relates to the technical field of concrete frames and discloses a lap joint type end plate connected full assembly type concrete frame construction method, which comprises the following steps: arranging two concrete columns, which are arranged in an up-down interval mode to form a butt joint node; the butt joint node is provided with a butt joint structure; the butt joint structure is provided with end plates on the two sides; two concrete beams are arranged, the concrete beams are provided with connecting ends; the connecting ends are outwardly horizontally extended with connecting sections, and the connecting sections are provided with connecting plates at the end portions; the butt joint structure at the outside of the butt joint node is used as a temporary lap joint platform for construction, the construction efficiency is improved, the two sides of the butt joint structure are respectively provided with the end plates, the end plates are arranged in a staggered type bending mode along the longitudinal direction, the two bending positions are abutted against each other, then the abutted end plates are fixed through high-strength bolts, the concrete frame is formed, the overall structure is stable, and the end plates and the connecting plates can be positioned when the end plates are butted against the connecting plates.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete frame, in particular to a lap joint end plate connection full assembly type concrete frame construction method. BACKGROUND

[0002] At present, concrete structures are widely developed in the construction industry of various countries. The whole pouring type concrete frame structure is one of the main application forms of concrete structures. This structure has the advantages of good integrity, large stiffness, and local material selection.

[0003] The full assembly type concrete frame structure can greatly improve the construction speed and efficiency. In order to promote the development of building industrialization, save a large amount of labor while ensuring engineering quality, improve production efficiency and save energy, and develop green and environmentally friendly buildings, the construction of full assembly type concrete frame is becoming a development trend of building structure development.

[0004] In the prior art, the full assembly type concrete frame includes a concrete column and a concrete beam. The concrete column and the concrete beam are connected at the butt joint. In order to achieve good connection strength at the butt joint, the transverse steel bars of the concrete beam are generally disconnected at the joint and connected by pouring a sleeve. The connection body is formed by pouring concrete into the pouring sleeve, and the fixed connection is realized to form the concrete frame. However, it has the problems of unstable connection and complex construction. SUMMARY

[0005] The purpose of the present application is to provide a lap joint end plate connection full assembly type concrete frame construction method, which aims to solve the problem of unstable overall structure of the full assembly type concrete frame in the prior art.

[0006] The present application is realized as follows. The lap joint end plate connection full assembly type concrete frame construction method comprises the following construction steps:

[0007] 1) arranging two longitudinally arranged concrete columns, the two concrete columns being arranged in an upper and lower spaced apart manner to form a butt joint, the butt joint being provided with a transversely arranged butt joint structure, the two concrete columns being longitudinally connected with the butt joint structure respectively, the butt joint structure having longitudinally arranged end plates on both sides thereof, the end plates being located outside the butt joint, and the end plates being arranged in a staggered bent manner along the longitudinal direction;

[0008] 2) arranging two transversely arranged concrete beams, the concrete beams having a connecting end facing the butt joint, the connecting end horizontally extending outwardly to form a connecting section, the connecting section being provided with a longitudinally arranged connecting plate at the end thereof, the connecting plate being arranged in a staggered bent manner along the longitudinal direction, and the bending direction of the connecting plate being opposite to that of the end plate;

[0009] The connecting plate and the end plate are horizontally and oppositely attached to each other, and the concrete beams are horizontally fixedly connected with the butt joint structure by bolts penetrating through the end plate and the connecting plate respectively, and the two concrete beams, the two concrete columns and the butt joint structure form a concrete frame;

[0010] 3) A formwork is arranged around the butt joint node, and concrete is poured into the butt joint node to form a connecting body filled with the butt joint node, and the connecting body is fixedly connected with the butt joint structure and the two concrete columns as a whole.

[0011] Optionally, longitudinal steel bars are arranged longitudinally in the concrete columns, and longitudinal shear plates are arranged at the two ends of the butt joint structure respectively; in the construction step 1), the longitudinal shear plates are inserted and fixed in the concrete columns and fixedly connected with the longitudinal steel bars.

[0012] Optionally, the butt joint structure comprises two horizontal support plates arranged horizontally and spaced apart from each other, the inner ends of the longitudinal shear plates are fixedly connected to the horizontal support plates, and the outer ends of the longitudinal shear plates extend outward.

[0013] Optionally, the longitudinal shear plate comprises two longitudinally arranged cross plates, the inner ends of the cross plates are fixedly connected to the horizontal support plates, and the outer ends of the cross plates extend outward; the middle portions of the two cross plates are connected to each other to form a cross position.

[0014] The two cross plates are arranged in a cross shape, and four shear intervals are formed between the two cross plates and arranged around the outer periphery of the cross position; in the construction step 1), when the longitudinal shear plates are inserted in the concrete columns, the longitudinal steel bars are inserted into the shear intervals.

[0015] Optionally, two longitudinal support plates are arranged longitudinally between the two horizontal support plates, and the longitudinal support plates are located inside the butt joint node; the middle portions of the two longitudinal support plates are connected to each other, the two longitudinal support plates are arranged in a cross shape, and four support intervals are formed between the two longitudinal support plates.

[0016] The two ends of the longitudinal support plates are fixedly connected to the two horizontal support plates respectively, and the horizontal support plates and the longitudinal support plates are integrally formed; in the construction step 3), the longitudinal support plates are wrapped inside the connecting body.

[0017] Optionally, the end of the longitudinal support plate is provided with a longitudinally arranged end plate, a plurality of the end plates are formed at the outer periphery of the two longitudinal support plates; the end of the longitudinal support plate is butted at the middle of the end plate, the two ends of the end plate are respectively correspondingly fixedly butted with the two horizontal support plates, and the adjacent end plates are spaced apart with a spacing opening with a communication support interval.

[0018] Optionally, the inner end of the connecting section extends to the outside of the connecting end, the connecting plate is arranged at the inner end of the connecting section; the outer end of the connecting section is provided with a transversely arranged shear plate, the shear plate is inserted and fixed in the concrete beam in the construction step 2).

[0019] Optionally, the concrete beam is provided with a transversely arranged transverse steel bar, the transverse steel bar is fixedly connected with the shear plate after the shear plate is inserted in the concrete beam in the construction step 2).

[0020] Optionally, along the direction from top to bottom, the middle of the connecting plate is outwardly staggered and bent away from the butt joint node to form a first step arranged downward, and the middle of the end plate is outwardly staggered and bent away from the butt joint node to form a second step arranged upward.

[0021] In the construction step 2), when the connecting plate and the end plate are horizontally and oppositely laminated, the first step is laminated on the second step from top to bottom.

[0022] Optionally, the outer periphery of the two longitudinal support plates is provided with a plurality of horizontally arranged internal hoops, the plurality of internal hoops are arranged at intervals along the longitudinal direction, and the inner sides of the internal hoops are respectively fixedly connected with the plurality of end plates; the outer periphery of the two longitudinal support plates is provided with a plurality of horizontally arranged external hoops, the plurality of external hoops are arranged at intervals along the longitudinal direction, the external hoops surround the outside of the internal hoops, and are located between the adjacent internal hoops.

[0023] Along the circumferential direction of the external hoop, the external hoop is curved outwardly away from the internal hoop to form a plurality of curved sections, and the plurality of curved sections are arranged at intervals along the circumferential direction of the external hoop; the external hoop has a plurality of arc sections between the adjacent curved sections, and the two ends of the arc section are respectively butted with the ends of the adjacent two curved sections.

[0024] The end of the curved section is connected with two inclined bars, the outer ends of the two inclined bars are fixedly connected at the end of the curved section, the inner ends of the two inclined bars are arranged separately, and are respectively butted on the adjacent internal hoops; in the construction step 3), the internal hoop, the inclined bar and the external hoop are respectively wrapped in the connecting body.

[0025] Compared with existing technologies, the lap-type end-plate connection fully prefabricated concrete frame construction method provided by this invention first installs and combines two concrete columns in a fully prefabricated manner, and then uses the docking structure at the external of the docking node as a temporary lap-type platform for construction, which improves construction efficiency. Furthermore, since the docking structure has end plates on both sides, and the end plates are arranged in a staggered bending pattern along the longitudinal direction, with the bending direction of the connecting plate opposite to that of the end plates, positioning can be achieved when the end plates and connecting plates overlap and connect. The two bending points fit together and are then fixed with high-strength bolts to form a concrete frame with overall structural stability. Moreover, by pouring concrete into the docking node, a connector is formed, which improves the overall strength of the concrete frame. Thus, this lap-type end-plate connection fully prefabricated installation method greatly improves construction efficiency and is safe and practical. Attached Figure Description

[0026] Figure 1 This is a cross-sectional schematic diagram of the concrete frame provided by the present invention;

[0027] Figure 2 This invention provides Figure 1 Enlarged view of point A in the middle;

[0028] Figure 3 This is a partial schematic diagram of the intersection provided by the present invention;

[0029] Figure 4 This is a schematic diagram of the arrangement of the two longitudinal support plates provided by the present invention;

[0030] Figure 5 This is a partial schematic diagram of the longitudinal support periphery provided by the present invention;

[0031] Figure 6 This invention provides Figure 5 A partial schematic diagram at point B in the middle. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0034] The same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components; in the description of the present application, it is understood that if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right" and the like are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation of the present patent, for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0035] Referring to Figures 1-6 The preferred embodiments provided by the present application are shown.

[0036] The lap joint end plate connection full assembly type concrete frame construction method provided by the present application comprises the following construction steps:

[0037] 1), arranging two longitudinally arranged concrete columns 100, the two concrete columns 100 are arranged in an upper and lower interval, forming a butt joint node 200; the butt joint node 200 is provided with a transversely arranged butt joint structure, the two concrete columns 100 are longitudinally butted with the butt joint structure respectively; the butt joint structure has longitudinally arranged end plates 210 on both sides respectively, the end plates 210 are located outside the butt joint node 200, and the end plates 210 are arranged in a staggered bending manner along the longitudinal direction;

[0038] 2), arranging two transversely arranged concrete beams 300, the concrete beams 300 have a connecting end facing the butt joint node 200; the connecting end extends outwardly and horizontally with a connecting section 302, the end of the connecting section 302 is provided with a longitudinally arranged connecting plate 310, the connecting plate 310 is arranged in a staggered bending manner along the longitudinal direction, and the bending direction of the connecting plate 310 is opposite to that of the end plate 210;

[0039] The connecting plate 310 and the end plate 210 are horizontally and oppositely attached and overlapped, the bolts 400 are used to pass through the end plate 210 and the connecting plate 310 respectively, so as to horizontally and fixedly connect the concrete beam 300 with the butt joint structure, and the two concrete beams 300, the two concrete columns 100 and the butt joint structure form a concrete frame;

[0040] 3), a formwork is arranged on the outer periphery of the butt joint node 200, and concrete is poured into the butt joint node 200, so as to form a connecting body filling the butt joint node 200, and the connecting body is fixedly connected with the butt joint structure and the two concrete columns 100 as a whole.

[0041] The lap joint end plate connection full assembly type concrete frame construction method provided above improves the construction efficiency by first installing two concrete columns 100 and using the butt joint structure at the outer part of the butt joint node 200 as a temporary lap joint platform for construction, and the overall structure of the concrete frame is more stable because the two sides of the butt joint structure each have an end plate 210 that is arranged in a staggered manner along the longitudinal direction, the bending direction of the connecting plate 310 is opposite to the bending direction of the end plate 210, and the two bending parts are fixed by high-strength bolts 400 after being attached to each other, the positioning effect is achieved when the end plate 210 and the connecting plate 310 are butted, and the construction efficiency is improved.

[0042] Furthermore, a formwork is arranged around the butt joint node 200, and concrete is poured into the butt joint node 200 to form a connecting body that improves the overall strength of the concrete frame.

[0043] The concrete column 100 is provided with longitudinal steel bars 101 arranged in the longitudinal direction, and the two ends of the butt joint structure are each provided with a longitudinal shear plate 110; in the construction step 1), the longitudinal shear plate 110 is inserted and fixed in the concrete column 100 and is fixedly connected with the longitudinal steel bars 101. In this way, the longitudinal shear plate 110 that is provided plays a role of resisting shearing force.

[0044] The butt joint structure includes two horizontal support plates 201 arranged in a horizontal and spaced-apart manner in the up-down direction, the inner end of the longitudinal shear plate 110 is fixedly butted on the horizontal support plate 201, and the outer end of the longitudinal shear plate 110 is arranged to extend outward. In this way, the concrete column 100 is fixedly formed by being butted on the horizontal support plate 201, and the longitudinal shear plate 110 effectively prevents the concrete column 100 from slipping relative to the horizontal support plate 201, thereby playing a role of resisting shearing force.

[0045] The longitudinal shear plate 110 includes two longitudinally arranged cross plates, the inner end of the cross plate is fixedly butted on the horizontal support plate 201, and the outer end of the cross plate is arranged to extend outward; the middle parts of the two cross plates are connected to each other to form a cross position.

[0046] The two cross plates are arranged in a cross shape, and the two cross plates enclose four shearing intervals 111 that are arranged around the outer periphery of the cross position; in the construction step 1), when the longitudinal shear plate 110 is inserted in the concrete column 100, the longitudinal steel bars 101 are inserted into the shearing intervals 111. In this way, the connection between the longitudinal shear plate 110 and the concrete column 100 is strengthened, the overall structure is more compact, the slipping between the concrete column 100 and the horizontal support plate 201 is prevented, and a role of resisting shearing force is played.

[0047] Two longitudinal support plates 202 are arranged longitudinally between the two horizontal support plates 201 and are located inside the butt joint node 200; the middle parts of the two longitudinal support plates 202 are connected and the two longitudinal support plates 202 are arranged in a cross shape, and four support intervals 2021 are formed between the two longitudinal support plates 202.

[0048] The two ends of the longitudinal support plate 202 are respectively fixedly connected with the two horizontal support plates 201, and the horizontal support plate 201 is integrally formed with the longitudinal support plate 202; in the construction step 3), the longitudinal support plate 202 is wrapped inside the connecting body.

[0049] The longitudinal support plate 202 plays a role of force conduction, and is arranged in a cross shape at the center of the horizontal support plate 201, so that the overall structure is more stable, and the connecting body is wrapped around the longitudinal support plate 202, thereby enhancing the load capacity of the longitudinal support plate 202 and making the structure more compact.

[0050] The end part of the longitudinal support plate 202 is provided with an end plate 2020 arranged longitudinally, and a plurality of end plates 2020 are formed on the outer periphery of the two longitudinal support plates 202; the end part of the longitudinal support plate 202 is connected to the middle part of the end plate 2020, the two ends of the end plate 2020 are respectively fixedly connected with the two horizontal support plates 201, and the adjacent end plates 2020 have a spacing opening communicating with the support interval 2021. In this way, the end plate 2020 makes the overall structure more compact and enables the overall longitudinal support plate 202 to bear a larger maximum load.

[0051] The inner end of the connecting section 302 extends to the outside of the connecting end, and the connecting plate 310 is arranged at the inner end of the connecting section 302; the outer end of the connecting section 302 is provided with a transverse shear plate 330 arranged longitudinally, and the transverse shear plate 330 is inserted and fixed in the concrete beam 300 in the construction step 2). In this way, the transverse shear plate 330 plays a role of shear resistance.

[0052] The transverse steel bars 301 are arranged transversely in the concrete beam 300, and the transverse steel bars 301 are fixedly connected with the transverse shear plate 330 after the transverse shear plate 330 is inserted in the concrete beam 300 in the construction step 2). In this way, the internal structure of the concrete beam 300 is more compact, and the sliding between the end plate 210 and the connecting plate 310 is effectively prevented.

[0053] In the direction from top to bottom, the middle part of the connecting plate 310 is outwardly offset and bent away from the butt joint node 200, and a first step 320 arranged downward is formed, and the middle part of the end plate 210 is outwardly offset and bent away from the butt joint node 200, and a second step 220 arranged upward is formed.

[0054] In the construction step 2), when the connecting plate 310 is horizontally and oppositely attached to the end plate 210, the first step 320 is overlapped on the second step 220 from top to bottom. In this way, during the process of opposite attachment, the first step 320 and the second step 220 play a role of quick positioning, greatly improving the accuracy and work efficiency, and the formed attachment structure is more compact and stable.

[0055] In the embodiment, the outer periphery of the two longitudinal support plates 202 is provided with a plurality of horizontally arranged internal hoops 500, the plurality of internal hoops 500 are arranged along the longitudinal direction, and the inner sides of the internal hoops 500 are fixedly connected with the plurality of end plates 2020 respectively; the outer periphery of the two longitudinal support plates 202 is provided with a plurality of horizontally arranged external hoops 600, the plurality of external hoops 600 are arranged along the longitudinal direction, the external hoops 600 surround the outside of the internal hoops 500 and are located between adjacent internal hoops 500.

[0056] Along the circumferential direction of the external hoop 600, the external hoop 600 is curved outward away from the internal hoop 500 to form a plurality of curved segments 601, and the plurality of curved segments 601 are arranged along the circumferential direction of the external hoop 600; the external hoop 600 has a plurality of arc segments 602, the arc segments 602 are located between adjacent curved segments 601, and the two ends of the arc segment 602 are respectively connected with the ends of the adjacent two curved segments 601.

[0057] The end of the curved segment 601 is connected with two inclined ribs 610, the outer ends of the two inclined ribs 610 are fixedly connected at the end of the curved segment 601, the inner ends of the two inclined ribs 610 are separately arranged and are respectively connected with the adjacent internal hoops 500; in the construction step 3), the internal hoops 500, the inclined ribs 610 and the external hoops 600 are wrapped in the connecting body.

[0058] In this way, the longitudinal support plate 202 is the main stress rib, when the connecting body bears a large load, the concrete in the connecting body is crushed or shearingly damaged outward along the inclined surface, the plurality of internal hoops 500 are arranged to play a restraining role, so as to avoid the outward bending damage of the longitudinal support plate 202. Similarly, the plurality of external hoops 600 are arranged to strengthen the restraining force and avoid the outward bending damage of the longitudinal support plate 202; at the same time, the two inclined ribs 610 are arranged at one end of the curved segment 601, the outer ends of the two inclined ribs 610 are connected together and connected at the end of the curved segment 601, the inner ends of the two inclined ribs 610 are connected with the adjacent internal hoops 500 to play a connecting role, so that the structure is more compact, the attachment node 200 has circumferential torsional resistance, and when a large torsion force occurs, a certain counteraction is generated between the internal hoops 500 and the external hoops 600 to offset the torsion force.

[0059] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of constructing a full assembly concrete frame with lap joint end plates, characterized in that, The construction steps include: 1) arranging two longitudinally arranged concrete columns, the two concrete columns are arranged in an upper and lower spaced manner, forming a butt joint node; the butt joint node is provided with a transversely arranged butt joint structure, the two concrete columns are longitudinally butted with the butt joint structure respectively; the butt joint structure is provided with longitudinally arranged end plates on both sides thereof, the end plates are located outside the butt joint node, and the end plates are arranged in a staggered bending manner along the longitudinal direction; 2) arranging two transversely arranged concrete beams, the concrete beams are provided with connecting ends facing the butt joint node; the connecting ends are outwardly horizontally extended with connecting sections, the connecting sections are provided with longitudinally arranged connecting plates at the end portions thereof, the connecting plates are arranged in a staggered bending manner along the longitudinal direction, and the bending directions of the connecting plates are opposite to the bending directions of the end plates; the connecting plates and the end plates are horizontally and oppositely attached and overlapped, bolts are used to pass through the end plates and the connecting plates respectively, the concrete beams and the butt joint structure are horizontally and fixedly connected, the two concrete beams, the two concrete columns and the butt joint structure form a concrete frame; 3) a formwork is arranged on the outer periphery of the butt joint node, and concrete is poured into the butt joint node to form a connecting body which fills the butt joint node, the connecting body is fixedly connected with the butt joint structure and the two concrete columns to form an integrated whole; the butt joint structure includes two horizontal support plates; two longitudinally arranged longitudinal support plates are arranged between the two horizontal support plates, the longitudinal support plates are located inside the butt joint node; the middle portions of the two longitudinal support plates are connected, the two longitudinal support plates are arranged in a cross shape, and four support intervals are formed between the two longitudinal support plates; the two ends of the longitudinal support plate are respectively correspondingly fixedly butted with the two horizontal support plates, and the horizontal support plate and the longitudinal support plate are integrally formed; in the construction step 3), the longitudinal support plate is wrapped inside the connecting body; end plates are arranged on the outer periphery of the longitudinal support plate, a plurality of end plates are formed on the outer periphery of the longitudinal support plate; the end portions of the longitudinal support plate are butted in the middle portions of the end plates, the two ends of the end plate are respectively correspondingly fixedly butted with the two horizontal support plates, and the adjacent end plates are spaced apart with interval openings which communicate with the support intervals; a plurality of horizontally arranged internal hoops are arranged on the outer periphery of the two longitudinal support plates, the internal hoops are arranged in a spaced apart manner along the longitudinal direction, and the internal hoops are fixedly connected with the plurality of end plates on the inner side thereof; a plurality of horizontally arranged external hoops are arranged on the outer periphery of the two longitudinal support plates, the external hoops are arranged in a spaced apart manner along the longitudinal direction, the external hoops surround the outside of the internal hoops, and are located between the adjacent internal hoops; the external hoops are curved outwardly away from the internal hoops along the circumferential direction of the external hoops, a plurality of curved sections are formed, and the curved sections are arranged in a spaced apart manner along the circumferential direction of the external hoops; the external hoops are provided with a plurality of arc-shaped sections, the arc-shaped sections are located between the adjacent curved sections, and the two ends of the arc-shaped section are respectively butted with the end portions of the adjacent two curved sections. The end of the curved section is connected with two inclined ribs, the outer ends of the two inclined ribs are fixedly connected at the end of the curved section, the inner ends of the two inclined ribs are separately arranged and respectively abut on the adjacent inner hoops; in the construction step 3), the inner hoops, the inclined ribs and the outer hoops are respectively wrapped in the connecting body.

2. The construction method of a full assembly type concrete frame with a lap flange connection according to claim 1, wherein The longitudinal shear plates are respectively inserted and fixed in the concrete column and fixedly connected with the longitudinal steel bars in the construction step 1).

3. The construction method of a full assembled concrete frame with lap flange connections according to claim 2, wherein, The inner ends of the longitudinal shear plates are fixedly abut on the horizontal support plates, and the outer ends of the longitudinal shear plates are outwardly extended.

4. The construction method of a fully assembled concrete frame with lap flange connections according to claim 3, wherein The longitudinal shear plates include two longitudinally arranged cross plates, the inner ends of the cross plates are fixedly abut on the horizontal support plates, and the outer ends of the cross plates are outwardly extended; the middle portions of the two cross plates are connected to form a cross position; The two cross plates are cross arranged in a cross shape, and four shear intervals are formed between the two cross plates, the four shear intervals are arranged along the outer periphery of the cross position; in the construction step 1), the longitudinal steel bars are inserted into the shear intervals after the longitudinal shear plates are inserted into the concrete column.

5. The construction method of a full assembly type concrete frame with a lap flange connection according to claim 1, wherein The inner end of the connecting section extends to the outside of the connecting end, and the connecting plate is arranged at the inner end of the connecting section; the outer end of the connecting section is provided with a transverse shear plate, the transverse shear plate is longitudinally arranged, and the transverse shear plate is inserted and fixed in the concrete beam in the construction step 2).

6. The construction method of a full assembled concrete frame with lap flange connections according to claim 5, wherein, The concrete beam is provided with transversely arranged transverse steel bars, and the transverse steel bars are fixedly connected with the transverse shear plates after the transverse shear plates are inserted into the concrete beam in the construction step 2).

7. The construction method of a full assembled concrete frame with lap flange connections according to any one of claims 1 to 6, wherein In the direction from top to bottom, the middle portion of the connecting plate is outwardly offset and bent away from the abutment node to form a first step arranged downward, and the middle portion of the end plate is outwardly offset and bent away from the abutment node to form a second step arranged upward. In the construction step 2), the first step is overlapped on the second step from top to bottom after the connecting plate and the end plate are horizontally and oppositely overlapped.

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