Prefabricated middle longitudinal beam and node structure and assembly method of assembled reverse underground structure

Abstract

The present invention belongs to the field of underground engineering technology, and specifically relates to a prefabricated center longitudinal beam of an assembled reverse-built underground structure, comprising a prefabricated left center longitudinal beam and a prefabricated right center longitudinal beam which are symmetrically arranged on the left and right and connected by high-strength bolts, the grooves at both ends of the prefabricated left center longitudinal beam are respectively opposed to the grooves at both ends of the prefabricated right center longitudinal beam to form a receiving groove for accommodating a steel pipe column; the node structure of the prefabricated center longitudinal beam and the steel pipe column comprises a steel pipe column and two opposed prefabricated center longitudinal beams, one end of the two prefabricated center longitudinal beams is supported on a bearing steel plate of the steel pipe column and connected to the bearing steel plate through embedded connectors; the assembly method of the node structure is to firstly hoist the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam from both sides to the installation position and fix them to the bearing steel plate, then fix their ends to the lateral steel plates, and finally fix the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam; the present invention can greatly reduce the difficulty of assembling the prefabricated center longitudinal beams, and can also increase the node strength.

Description

Technical Field

[0001] The invention belongs to the technical field of underground engineering, and in particular relates to a prefabricated middle longitudinal beam of an assembled reverse-built underground structure, a node structure between the beam and a steel pipe column, and an assembly method of the node structure. Background Art

[0002] With the development of prefabricated technology, prefabricated underground structural projects such as subway stations have also appeared one after another. At present, prefabricated structures are often constructed using the open-cut method, but open-cut will cause traffic congestion on the ground surface, leading to inconvenience in travel. Therefore, in order to overcome the shortcomings of the open-cut method, the cover-excavation reverse construction method is adopted to quickly restore road traffic and reduce the impact of construction on road traffic.

[0003] Problems in assembling longitudinal beams in the prefabrication of subway stations using prefabricated reverse construction:

[0004] (1) During the construction of the prefabricated center longitudinal beam of the subway station by top-down construction, the top plate and top longitudinal beam have been completed. The center longitudinal beam cannot be directly suspended from the top of the steel column and can only be horizontally suspended from one side of the steel column and then vertically suspended. Therefore, the length of the prefabricated center longitudinal beam must be less than the clear distance between the two steel pipe columns, which limits the connection area between the prefabricated center longitudinal beam and the steel pipe column, which is not conducive to force bearing.

[0005] (2) The weight of a single prefabricated longitudinal beam exceeds 15 tons, which makes it very difficult to hoist it in the limited space below the top plate.

[0006] Therefore, it is necessary to provide a prefabricated middle longitudinal beam of an assembled reverse-built underground structure, a node structure between the beam and the steel pipe column, and an assembly method of the node structure to solve the above problems. Summary of the invention

[0007] In order to overcome the deficiencies of the above-mentioned prior art, the purpose of the present invention is to provide a prefabricated center longitudinal beam of an assembled reverse-built underground structure, a node structure between the center longitudinal beam and a steel pipe column, and an assembly method of the node structure, which can not only greatly reduce the difficulty of assembling the prefabricated center longitudinal beam, but also increase the connection strength between the center longitudinal beam and the steel pipe column, while greatly reducing the difficulty of lifting and assembly.

[0008] To achieve the above-mentioned purpose, the technical solution of the present invention is a prefabricated center longitudinal beam of an assembled reverse-built underground structure, including a prefabricated left center longitudinal beam and a prefabricated right center longitudinal beam, the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam are symmetrically arranged on the left and right and connected by high-strength bolts; both ends of the prefabricated left center longitudinal beam and both ends of the prefabricated right center longitudinal beam are provided with grooves penetrating along the thickness direction of the prefabricated center longitudinal beam, and the grooves at both ends of the prefabricated left center longitudinal beam are respectively opposed to the grooves at both ends of the prefabricated right center longitudinal beam to form accommodating grooves; both ends of the prefabricated left center longitudinal beam and both ends of the prefabricated right center longitudinal beam are provided with embedded connecting parts.

[0009] Optimally, the groove is a 1 / 4 arc-shaped groove, and the accommodating groove is a semicircular groove.

[0010] Furthermore, a plurality of bolt holes are provided on the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam, and the bolt holes on the prefabricated left center longitudinal beam correspond one to one with the bolt holes on the prefabricated right center longitudinal beam; the high-strength bolts pass through the bolt holes on the prefabricated right center longitudinal beam and the corresponding bolt holes on the prefabricated left center longitudinal beam.

[0011] Furthermore, the embedded connecting parts include a beam bottom steel plate and vertical fixing bolts. The beam bottom steel plate is embedded in the bottom of the prefabricated left middle longitudinal beam or the prefabricated right middle longitudinal beam, and vertical fixing bolts are welded on the bottom surface of the beam bottom steel plate.

[0012] The present invention also provides a node structure of prefabricated center longitudinal beams and steel pipe columns of an assembled reverse-built underground structure, including steel pipe columns and two of the above-mentioned prefabricated center longitudinal beams; the steel pipe columns are provided with load-bearing steel plates surrounding their outer walls, one end of each of the prefabricated center longitudinal beams is placed on the load-bearing steel plate, and the receiving grooves of the two prefabricated center longitudinal beams are opposed to each other to form a through hole, and the steel pipe columns pass through the through hole; the embedded connecting parts on the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam are both connected to the load-bearing steel plates.

[0013] Furthermore, vertical fixing bolt holes are provided on the bearing steel plate at positions corresponding to the two prefabricated left-side center longitudinal beams and the two prefabricated right-side center longitudinal beams, and the vertical fixing bolt holes correspond one-to-one to the vertical fixing bolts of the embedded connecting parts, and the vertical fixing bolts pass through the corresponding vertical fixing bolt holes and are fixed by nuts.

[0014] Furthermore, lateral steel plates are connected to both sides of the load-bearing steel plate, the ends of the two prefabricated center longitudinal beams placed on the load-bearing steel plate are located between the two lateral steel plates, and the ends of the prefabricated center longitudinal beams are fixed to the two lateral steel plates by high-strength bolts.

[0015] Furthermore, the ends of the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam placed between the two lateral steel plates are provided with bolt holes, and the lateral steel plates are provided with horizontal fixing bolt holes at positions corresponding to the bolt holes; the high-strength bolts pass through the corresponding horizontal fixing bolt holes and bolt holes along the width direction of the prefabricated center longitudinal beam to fix the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam to the two lateral steel plates.

[0016] Furthermore, the bottom surface of the bearing plate is connected to the steel pipe column via a supporting angle iron.

[0017] The present invention also provides a method for assembling the node structure of the prefabricated middle longitudinal beam and the steel pipe column of the above-mentioned assembled reverse underground structure, comprising the following steps:

[0018] 1) Transport the two prefabricated left-side middle longitudinal beams from the left-side space of the station to the designated column span position, move the prefabricated left-side middle longitudinal beam horizontally to the top of the installation position, drop it, place the vertical fixing bolts of the embedded connector at the bottom of the prefabricated left-side middle longitudinal beam into the corresponding vertical fixing bolt holes on the bearing steel plate, and tighten the bolts;

[0019] Transport the two prefabricated right side middle longitudinal beams from the right side space of the station to the designated column span position, move the prefabricated right side middle longitudinal beam horizontally to just above the installation position, drop it, place the vertical fixing bolts of the embedded connector at the bottom of the prefabricated right side middle longitudinal beam into the corresponding vertical fixing bolt holes on the bearing steel plate, and tighten the bolts;

[0020] 2) Insert high-strength bolts through the horizontal fixing bolt holes on the lateral steel plate on one side of the load-bearing steel plate to fix the prefabricated right side center longitudinal beam and the prefabricated left side center longitudinal beam of the prefabricated center longitudinal beam to the lateral steel plate on the other side;

[0021] 3) Insert high-strength bolts into the bolt holes on the prefabricated left center longitudinal beam and the bolt holes on the prefabricated right center longitudinal beam of the prefabricated center longitudinal beam, and tighten them to fix the prefabricated center longitudinal beam into a whole, completing the assembly of the node structure.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention adopts the method of left and right center longitudinal beams to decompose the traditional single-piece center longitudinal beam, which greatly reduces the difficulty of assembling the prefabricated center longitudinal beam and increases the connection strength between the center longitudinal beam and the steel pipe column;

[0024] (2) The present invention divides the 15t center longitudinal beam into two parts by splitting the prefabricated center longitudinal beam into a prefabricated left center longitudinal beam and a prefabricated right center longitudinal beam, thereby greatly reducing the difficulty of lifting and assembly;

[0025] (3) After the prefabricated left middle longitudinal beam and the prefabricated right middle longitudinal beam are firmly connected by high-strength bolts, the force is basically equivalent to that of a single complete beam, and can fully bear the middle plate load;

[0026] (4) The end of the prefabricated left center longitudinal beam and the end of the prefabricated left center longitudinal beam of the present invention both adopt a 1 / 4 arc-shaped groove. After the node is assembled, a through hole is formed to surround the entire steel pipe column, thereby increasing the contact area between the prefabricated center longitudinal beam and the steel column, which is more conducive to force bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A top view of a prefabricated middle longitudinal beam of an assembled reverse-built underground structure provided in an embodiment of the present invention;

[0029] Figure 2 A cross-sectional view of a prefabricated middle longitudinal beam of an assembled reverse-built underground structure provided in an embodiment of the present invention;

[0030] Figure 3 A top view of a bearing steel plate on a steel pipe column for supporting a prefabricated middle longitudinal beam provided in an embodiment of the present invention;

[0031] Figure 4 A side view of a bearing steel plate for supporting a prefabricated middle longitudinal beam on a steel pipe column provided in an embodiment of the present invention;

[0032] Figure 5 A front view of a bearing steel plate on a steel pipe column for supporting a prefabricated middle longitudinal beam provided in an embodiment of the present invention;

[0033] Figure 6 A cross-sectional view of a node structure of a prefabricated middle longitudinal beam and a steel pipe column of an assembled reverse-built underground structure provided by an embodiment of the present invention;

[0034] In the figure: 1. Prefabricated left center longitudinal beam; 2. Prefabricated right center longitudinal beam; 3. Bolt holes; 4. Beam bottom steel plate; 5. Vertical fixing bolts; 6. Load-bearing steel plate; 7. Steel pipe column; 8. Vertical fixing bolt holes; 9. Lateral steel plate; 10. Horizontal fixing bolt holes; 11. Support angle iron; 12. High-strength bolts. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] 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 one or more of the features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0038] Embodiment 1

[0039] like Figure 1-Figure 2 As shown, the present embodiment provides a prefabricated center longitudinal beam of an assembled reverse-built underground structure, including a prefabricated left center longitudinal beam 1 and a prefabricated right center longitudinal beam 2, the prefabricated left center longitudinal beam 1 and the prefabricated right center longitudinal beam 2 are symmetrically arranged on the left and right and connected by high-strength bolts 12; both ends of the prefabricated left center longitudinal beam 1 and both ends of the prefabricated right center longitudinal beam 2 are provided with grooves penetrating along the thickness direction of the prefabricated center longitudinal beam, and the grooves at both ends of the prefabricated left center longitudinal beam 1 are respectively opposed to the grooves at both ends of the prefabricated right center longitudinal beam 2 to form accommodating grooves for accommodating steel pipe columns 7; both ends of the prefabricated left center longitudinal beam 1 and both ends of the prefabricated right center longitudinal beam 2 are provided with embedded connecting parts for positioning and connecting the steel pipe columns 7. This embodiment divides the prefabricated center longitudinal beam into a prefabricated left center longitudinal beam 1 and a prefabricated right center longitudinal beam 2, and divides the prefabricated center longitudinal beam weighing 15 tons into two, thereby greatly reducing the difficulty of lifting and assembly and saving the investment in large-scale lifting equipment; at the same time, it provides the possibility of prefabricating and assembling the center longitudinal beam of the subway station by prefabricated reverse construction, which greatly saves construction time compared with the cast-in-place center longitudinal beam, is simple, convenient, and environmentally friendly.

[0040] Optimally, the grooves at both ends of the prefabricated left center longitudinal beam 1 and the grooves at both ends of the prefabricated right center longitudinal beam 2 can both be 1 / 4 arc-shaped grooves, and the receiving grooves are semicircular grooves. In this embodiment, the grooves at the ends of the prefabricated left center longitudinal beam 1 and the grooves at the ends of the prefabricated right center longitudinal beam 2 are designed according to the shape and size of the steel pipe column 7, and through holes are formed after the nodes are assembled to surround the entire steel pipe column 7, thereby increasing the contact area between the prefabricated center longitudinal beam and the steel pipe column 7, which is more conducive to force. Figure 1As shown, the 1 / 4 arc-shaped groove of the prefabricated left middle longitudinal beam 1 of this embodiment is opposed to the 1 / 4 arc-shaped groove of the prefabricated right middle longitudinal beam 2 to form a semicircular groove, which is suitable for the nodes of cylindrical steel pipe columns and is conducive to prefabrication. The grooves at both ends of the prefabricated left middle longitudinal beam 1 and the grooves at both ends of the prefabricated right middle longitudinal beam 2 may not be 1 / 4 arc-shaped grooves, as long as the formed receiving grooves are semicircular grooves, they can also be used for the nodes of cylindrical steel pipe columns. In addition, the prefabricated middle longitudinal beam of this embodiment is also suitable for steel pipe columns of other shapes such as square, as long as the through holes formed by the opposing receiving grooves of the two prefabricated middle longitudinal beams can surround the steel pipe column.

[0041] Furthermore, a plurality of bolt holes 3 are provided on the prefabricated left center longitudinal beam 1 and the prefabricated right center longitudinal beam 2. The bolt holes 3 extend along the width direction of the prefabricated center longitudinal beam, and the bolt holes 3 on the prefabricated left center longitudinal beam 1 correspond to the bolt holes 3 on the prefabricated right center longitudinal beam 2 one by one. The high-strength bolts 12 pass through the bolt holes 3 on the prefabricated right center longitudinal beam 2 and the corresponding bolt holes 3 on the prefabricated left center longitudinal beam 1. Figure 1 and Figure 2 As shown, in this embodiment, the bolt holes 3 on the prefabricated left center longitudinal beam 1 correspond one to one with the bolt holes 3 on the prefabricated right center longitudinal beam 2 and are precisely aligned to avoid installation difficulties and uneven force; and hexagonal nut holes are reserved at the ends of the bolt holes 3 on the left center longitudinal beam to facilitate the loading and unloading of the high-strength bolts 12.

[0042] Furthermore, the upper and lower parts of the prefabricated left center longitudinal beam 1 are provided with multiple bolt holes 3 at intervals along the length direction of the prefabricated left center longitudinal beam 1, and the upper and lower parts of the prefabricated right center longitudinal beam 2 are provided with multiple bolt holes 3 at intervals along the length direction of the prefabricated right center longitudinal beam 2. The upper and lower parts of the prefabricated left center longitudinal beam 1 are respectively connected to the upper and lower parts of the prefabricated right center longitudinal beam 2 by high-strength bolts 12. Optimally, the prefabricated center longitudinal beam is provided with no less than 5 groups of bolt holes 3 in the longitudinal section direction, i.e., along its length direction, and no less than 3 groups of bolt holes 3 in the cross-section direction, i.e., along its thickness direction, and the diameter of the high-strength bolts 12 is no less than 30 mm, so as to ensure that the prefabricated left center longitudinal beam 1 and the prefabricated right center longitudinal beam 2 can bear force together.

[0043] Further, the embedded connection member includes a beam bottom steel plate 4 and a vertical fixing bolt 5, the beam bottom steel plate 4 is embedded in the bottom of the prefabricated left middle longitudinal beam 1 or the prefabricated right middle longitudinal beam 2, and the vertical fixing bolt 5 is welded on the bottom surface of the beam bottom steel plate 4. The beam bottom steel plate 4 of this embodiment is tightly connected to the longitudinal steel bars in the corresponding prefabricated left middle longitudinal beam 1 or the prefabricated right middle longitudinal beam 2, and the vertical fixing bolt 5 is fixed on the bottom surface of the beam bottom steel plate 4 for easy positioning and assembly.

[0044] Embodiment 2

[0045] like Figure 4-Figure 6As shown, this embodiment provides a node structure of a prefabricated middle longitudinal beam and a steel pipe column 7 of an assembled reverse underground structure, including a steel pipe column 7 and two prefabricated middle longitudinal beams as in the first embodiment; a bearing steel plate 6 surrounding the outer wall is reserved on the steel pipe column 7, one end of each prefabricated middle longitudinal beam is placed on the bearing steel plate 6, and the receiving grooves of the two prefabricated middle longitudinal beams are opposite to form a through hole, and the steel pipe column 7 passes through the through hole; the embedded connectors on the prefabricated left middle longitudinal beam 1 and the prefabricated right middle longitudinal beam 2 are both connected to the bearing steel plate 6. In the node structure of this embodiment, the steel pipe column 7 passes through the through hole enclosed by the two prefabricated left middle longitudinal beams 1 and the two prefabricated right middle longitudinal beams 2; and in the horizontal direction, the prefabricated left middle longitudinal beam 1 and the prefabricated right middle longitudinal beam 2 are connected by high-strength bolts 12, and in the vertical direction, the prefabricated left middle longitudinal beam 1 and the prefabricated right middle longitudinal beam 2 are connected to the bearing steel plate 6 on the steel pipe column 7 by embedded connectors, which increases the connection strength between the prefabricated middle longitudinal beam and the steel pipe column 7.

[0046] Furthermore, vertical fixing bolt holes 8 are provided on the bearing steel plate 6 at positions corresponding to the two prefabricated left middle longitudinal beams 1 and the two prefabricated right middle longitudinal beams 2. The vertical fixing bolt holes 8 correspond to the vertical fixing bolts 5 of the embedded connectors one by one, and the vertical fixing bolts 5 pass through the corresponding vertical fixing bolt holes 8 and are fixed by nuts. The steel pipe column 7 of this embodiment reserves the bearing steel plate 6 at the design elevation position, such as Figure 3 As shown, four vertical fixing bolt holes 8 are reserved in the bearing steel plate 6, and the vertical fixing bolts 5 welded on the beam bottom steel plate 4 embedded at the ends of the two prefabricated left center longitudinal beams 1 and the two prefabricated right center longitudinal beams 2 in the node structure respectively pass through the four vertical fixing bolt holes 8 and are fixed by nuts to fix the prefabricated left center longitudinal beam 1 and the prefabricated right center longitudinal beam 2 to the bearing steel plate 6.

[0047] Furthermore, both sides of the bearing steel plate 6 are connected with lateral steel plates 9, and the ends of the two prefabricated middle longitudinal beams placed on the bearing steel plate 6 are located between the two lateral steel plates 9, and the ends of the prefabricated middle longitudinal beams are fixed to the two lateral steel plates 9 by high-strength bolts 12. In this embodiment, lateral steel plates 9 are provided on the sides of the bearing steel plate 6 to limit the horizontal displacement of the prefabricated left middle longitudinal beam 1 and the prefabricated right middle longitudinal beam 2. Furthermore, the ends of the prefabricated left middle longitudinal beam 1 and the prefabricated right middle longitudinal beam 2 placed between the two lateral steel plates 9 are provided with bolt holes 3, and the positions corresponding to the bolt holes 3 on the lateral steel plates 9 are provided with horizontal fixing bolt holes 10; the high-strength bolts 12 pass through the corresponding horizontal fixing bolt holes 10 and the bolt holes 3 along the width direction of the prefabricated middle longitudinal beam to fix the prefabricated left middle longitudinal beam 1 and the prefabricated right middle longitudinal beam 2 to the two lateral steel plates 9.

[0048] Furthermore, the bottom surface of the bearing plate is connected to the steel pipe column 7 through a supporting angle iron 11. The size of the supporting angle iron 11 of this embodiment is determined according to the size of the bearing steel plate 6 extending out of the steel pipe column 7. The supporting angle iron 11 should have sufficient strength and be firmly connected to the steel pipe column 7 and the bearing steel plate 6 to increase the shear resistance.

[0049] In this embodiment, the thickness of the load-bearing steel plate 6 is not less than 30 mm, and the thickness of the lateral steel plate 9 is not less than 20 mm; the prefabricated left center longitudinal beam 1, the prefabricated right center longitudinal beam 2 and the beam bottom steel plate 4 embedded at the beam end should all have sufficient thickness.

[0050] Embodiment 3

[0051] like Figure 1-Figure 6 As shown, this embodiment provides an assembly method of the node structure of the prefabricated middle longitudinal beam and the steel pipe column 7 of the assembled reverse underground structure as in the second embodiment, comprising the following steps:

[0052] 1) Transport the two prefabricated left-side middle longitudinal beams 1 from the left-side space of the station to the designated column span position, move the prefabricated left-side middle longitudinal beam 1 horizontally to just above the installation position, drop it, place the vertical fixing bolts 5 of the embedded connector at the bottom of the prefabricated left-side middle longitudinal beam 1 into the corresponding vertical fixing bolt holes 8 on the bearing steel plate 6, and tighten the bolts;

[0053] Similarly, assemble the prefabricated right middle longitudinal beam 2, transport the two prefabricated right middle longitudinal beams 2 from the right side of the station to the designated column span position, move the prefabricated right middle longitudinal beam 2 horizontally to just above the installation position, drop it, place the vertical fixing bolts 5 of the embedded connector at the bottom of the prefabricated right middle longitudinal beam 2 into the corresponding vertical fixing bolt holes 8 on the bearing steel plate 6, and tighten the bolts;

[0054] At this time, the grooves of the two prefabricated left middle longitudinal beams 1 and the grooves of the two prefabricated right middle longitudinal beams 2 form a through hole, and the steel pipe column 7 is wrapped in the through hole;

[0055] 2) Insert high-strength bolts 12 through the horizontal fixing bolt holes 10 on the lateral steel plate 9 on one side of the bearing steel plate 6 to fix the prefabricated right side middle longitudinal beam 2 and the prefabricated left side middle longitudinal beam 1 of the prefabricated middle longitudinal beam to the lateral steel plate 9 on the other side;

[0056] 3) Insert the high-strength bolts 12 into the bolt holes 3 on the prefabricated left center longitudinal beam 1 and the bolt holes 3 on the prefabricated right center longitudinal beam 2 of the prefabricated center longitudinal beam, and tighten them to fix the prefabricated center longitudinal beam into a whole, thereby completing the assembly of the node structure.

[0057] In this embodiment, the prefabricated center longitudinal beam is divided into two parts for prefabrication, namely, a prefabricated left center longitudinal beam 1 and a prefabricated right center longitudinal beam 2. They are prefabricated separately in the prefabrication yard, which is more conducive to lifting and assembly. Subsequently, they are lifted and assembled from both sides of the steel pipe column 7, which greatly reduces the difficulty of assembling the prefabricated center longitudinal beam, and the maximum length of the prefabricated center longitudinal beam is no longer limited to the net distance between the two steel pipe columns 7. The ends of the prefabricated left center longitudinal beam 1 and the prefabricated right center longitudinal beam 2 can adopt a 1 / 4 arc groove design, which wraps the entire cylindrical steel pipe column 7 to increase the contact area between the prefabricated center longitudinal beam and the steel pipe column 7, which is more conducive to force. The single-piece prefabricated left center longitudinal beam 1 or the prefabricated right center longitudinal beam 2 is first assembled in the suspended slot of the load-bearing steel plate 6 reserved in the steel pipe column 7, and is vertically fixed by means of vertical fixing bolts 5 to transfer the vertical load to the steel pipe column 7; after the two prefabricated center longitudinal beams are assembled, the corresponding prefabricated left center longitudinal beam 1 and the prefabricated right center longitudinal beam 2 are connected as a whole by means of high-strength bolts 12, so that they are subjected to force together and can fully withstand the load of the subway station center plate.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A node structure of a prefabricated middle longitudinal beam and a steel pipe column of an assembled reverse underground structure, characterized in that: It comprises a steel pipe column and two prefabricated middle longitudinal beams; a bearing steel plate surrounding the outer wall of the steel pipe column is reserved, one end of each of the prefabricated middle longitudinal beams is placed on the bearing steel plate, and the receiving grooves of the two prefabricated middle longitudinal beams are opposite to each other to form a through hole, and the steel pipe column passes through the through hole; the embedded connectors on the prefabricated left middle longitudinal beam and the prefabricated right middle longitudinal beam are both connected to the bearing steel plate; The prefabricated center longitudinal beam comprises a prefabricated left center longitudinal beam and a prefabricated right center longitudinal beam, the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam are symmetrically arranged and connected by high-strength bolts; both ends of the prefabricated left center longitudinal beam and both ends of the prefabricated right center longitudinal beam are provided with grooves penetrating along the thickness direction of the prefabricated center longitudinal beam, and the grooves at both ends of the prefabricated left center longitudinal beam are respectively opposite to the grooves at both ends of the prefabricated right center longitudinal beam to form accommodating grooves; both ends of the prefabricated left center longitudinal beam and both ends of the prefabricated right center longitudinal beam are provided with embedded connecting pieces; The embedded connecting parts include a beam bottom steel plate and vertical fixing bolts. The beam bottom steel plate is embedded in the bottom of the prefabricated left middle longitudinal beam or the prefabricated right middle longitudinal beam, and vertical fixing bolts are welded on the bottom surface of the beam bottom steel plate.

2. The node structure of the prefabricated middle longitudinal beam and the steel pipe column of the assembled reverse underground structure according to claim 1, characterized in that: The groove is a 1 / 4 arc-shaped groove, and the accommodating groove is a semicircular groove.

3. The node structure of the prefabricated middle longitudinal beam and the steel pipe column of the assembled reverse underground structure according to claim 1, characterized in that: A plurality of bolt holes are provided on the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam, and the bolt holes on the prefabricated left center longitudinal beam correspond one to one with the bolt holes on the prefabricated right center longitudinal beam; the high-strength bolts pass through the bolt holes on the prefabricated right center longitudinal beam and the corresponding bolt holes on the prefabricated left center longitudinal beam.

4. The node structure of the prefabricated middle longitudinal beam and the steel pipe column of the assembled reverse underground structure according to claim 1, characterized in that: Vertical fixing bolt holes are provided on the bearing steel plate at positions corresponding to the two prefabricated left-side center longitudinal beams and the two prefabricated right-side center longitudinal beams. The vertical fixing bolt holes correspond one-to-one to the vertical fixing bolts of the embedded connecting parts, and the vertical fixing bolts pass through the corresponding vertical fixing bolt holes and are fixed by nuts.

5. The node structure of the prefabricated middle longitudinal beam and the steel pipe column of the assembled reverse underground structure according to claim 1, characterized in that: Both sides of the load-bearing steel plate are connected with lateral steel plates, the ends of the two prefabricated middle longitudinal beams placed on the load-bearing steel plate are located between the two lateral steel plates, and the ends of the prefabricated middle longitudinal beams are fixed to the two lateral steel plates by high-strength bolts.

6. The node structure of the prefabricated middle longitudinal beam and the steel pipe column of the assembled reverse underground structure according to claim 5, characterized in that: The ends of the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam placed between the two lateral steel plates are provided with bolt holes, and the lateral steel plates are provided with horizontal fixing bolt holes at positions corresponding to the bolt holes; the high-strength bolts pass through the corresponding horizontal fixing bolt holes and bolt holes along the width direction of the prefabricated center longitudinal beam to fix the prefabricated left center longitudinal beam and the prefabricated right center longitudinal beam to the two lateral steel plates.

7. The node structure of the prefabricated middle longitudinal beam and the steel pipe column of the assembled reverse underground structure according to claim 1, characterized in that: The bottom surface of the bearing steel plate is connected to the steel pipe column through a supporting angle iron.

8. An assembly method for the node structure of the prefabricated middle longitudinal beam and the steel pipe column of the assembled reverse underground structure according to any one of claims 1 to 7, characterized in that: The steps include: 1) Transport the two prefabricated left-side middle longitudinal beams from the left-side space of the station to the designated column span position, move the prefabricated left-side middle longitudinal beam horizontally to just above the installation position, drop it, place the vertical fixing bolts of the embedded connector at the bottom of the prefabricated left-side middle longitudinal beam into the corresponding vertical fixing bolt holes on the bearing steel plate, and tighten the bolts; Transport the two prefabricated right side middle longitudinal beams from the right side space of the station to the designated column span position, move the prefabricated right side middle longitudinal beam horizontally to just above the installation position, drop it, place the vertical fixing bolts of the embedded connector at the bottom of the prefabricated right side middle longitudinal beam into the corresponding vertical fixing bolt holes on the bearing steel plate, and tighten the bolts; 2) Insert high-strength bolts through the horizontal fixing bolt holes on the lateral steel plate on one side of the load-bearing steel plate to fix the prefabricated right middle longitudinal beam and the prefabricated left middle longitudinal beam of the prefabricated middle longitudinal beam to the lateral steel plate on the other side; 3) Insert high-strength bolts into the bolt holes on the prefabricated left center longitudinal beam and the bolt holes on the prefabricated right center longitudinal beam of the prefabricated center longitudinal beam, and tighten them to fix the prefabricated center longitudinal beam into a whole, thereby completing the assembly of the node structure.

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