A shield tunnel assembled rail top air duct structure

Abstract

The present invention provides a shield tunnel assembled track top air duct structure, including a prefabricated air duct plate, a prefabricated vertical partition wall, a π-type connector and a steel bracket connector, wherein the prefabricated air duct plate is horizontally arranged, the prefabricated vertical partition wall is vertically assembled above the prefabricated air duct plate, the π-type connector is assembled above the prefabricated vertical partition wall and is used to connect with the pipe segment in the tunnel, and the steel bracket connector is assembled at one end of the prefabricated air duct plate and is used to connect with the pipe segment in the tunnel. The present invention can avoid the disadvantages of traditional cast-in-place construction that requires drilling and planting reinforcement to damage the pipe segment structure, and achieves the purpose of not damaging the pipe segment structure and speeding up the installation speed through the prefabricated component assembly design.

Description

Technical Field

[0001] The invention belongs to the field of building construction, and in particular relates to an assembled rail-top air duct structure for a shield tunnel. Background Art

[0002] At present, in the construction of urban rail transit in China, subway stations are mainly built by open-cut method, and interval tunnels are mainly constructed by shield method. Due to various factors such as land acquisition and demolition, traffic relief, etc., there may be special situations where the shield method is used in conjunction with the construction of stations. The shield station is a side platform station composed of two parallel circular tunnels. It is currently less used in China. Generally, a large-diameter (greater than 6 meters) shield machine is used. Through the method of tunneling first and then stationing, the track is laid in the shield tunnel and the platform plate, rail-top air duct and other internal structures are set up. Passengers enter the platform from the shafts at both ends of the station to take the train.

[0003] The track-top duct is the exhaust passage in the station, which is suspended at the junction of the middle plate and the side wall of the structure. The cast-in-place method is mainly used in China. However, when setting up the track-top duct structure for shield stations, if the traditional cast-in-place method is used, it is necessary to drill holes and plant reinforcement on the tunnel segments, which not only takes a long time to complete and the construction quality is difficult to guarantee, but also has an adverse effect on the durability of the structure.

[0004] At present, a large number of prefabricated structures are used in domestic construction projects. The components are prefabricated in the factory and transported to the site for assembly, which is simple to install and fast in construction. Therefore, it is necessary to propose a fully assembled track-top air duct structure using prefabricated components in the case of setting up a secondary structure of the track-top air duct in an existing shield tunnel, so as to avoid the damage of drilling and planting reinforcement to the tunnel structure. Summary of the invention

[0005] The present invention is proposed to solve the problems existing in the prior art. Its purpose is to provide an assembled track-top air duct structure for a shield tunnel, which can avoid the shortcomings of traditional cast-in-place construction method that requires drilling and planting reinforcement to damage the segment structure. Through the prefabricated component assembly design, the purpose of not damaging the segment structure and speeding up the installation is achieved.

[0006] The shield tunnel assembled track top air duct structure of the present invention comprises a prefabricated air duct plate, a prefabricated vertical partition wall, a π-shaped connector and a steel corbel connector. The prefabricated air duct plate is horizontally arranged, the prefabricated vertical partition wall is vertically assembled above the prefabricated air duct plate, the π-shaped connector is assembled above the prefabricated vertical partition wall and is used to connect with the pipe segments in the tunnel, and the steel corbel connector is assembled at one end of the prefabricated air duct plate and is used to connect with the pipe segments in the tunnel.

[0007] Wherein, the π-shaped connector and the steel corbel connector are provided with strip bolt holes capable of adjusting errors; and a T-shaped sleeve for connection is pre-buried in the tunnel segment.

[0008] Among them, the prefabricated air duct plate is L-shaped and uses UHPC ultra-high performance concrete material. The thickness of the long side of the L-shape is 1 / 3 to 1 / 2 of the general cast-in-place rail top air duct structure, and the short side of the L-shape is locally thickened for installing the shielding door. The prefabricated air duct plate is provided with embedded sleeves for connecting with the prefabricated vertical partition wall and steel corbel connector respectively.

[0009] Among them, the prefabricated vertical partition wall is in an inverted T shape and is made of UHPC ultra-high performance concrete material. The thickness of the long side of the T shape is 1 / 3 to 1 / 2 of the general cast-in-place rail top air duct structure, and the short side of the T shape is partially thickened. The prefabricated vertical partition wall is provided with embedded sleeves for connecting to the π-type connector and the prefabricated air duct plate respectively.

[0010] Among them, the π-shaped connecting piece includes an arc-shaped base for connecting with the pipe segments in the tunnel, a vertical wall is arranged below the arc-shaped base, and the vertical wall is connected to the arc-shaped base by a diagonal brace to increase the structural force; the vertical wall is located in the middle part below the arc-shaped base and slightly biased to one side; the prefabricated vertical partition wall can be inserted and fixed between the vertical walls.

[0011] Furthermore, a longitudinal connecting plate is provided on the outer side of the vertical wall, and the prefabricated vertical partition wall is clamped and fixed between the vertical wall and the longitudinal connecting plate by fastening connectors; the surfaces of the vertical wall and the longitudinal connecting plate that contact each other are provided with teeth that can mesh with each other; the fastening connectors are connecting bolts and anti-loosening double nuts that can cooperate with them at the other end; strip bolt holes that can adjust errors are provided on the vertical wall; two π-type connectors are arranged parallel to the longitudinal connecting plate on each ring of the pipe segment; the π-type connectors are welded and formed by Q355B steel plates, the seams are fully welded, and the surface is treated with anti-corrosion and fireproofing.

[0012] Among them, the steel corbel connector includes an arc-shaped base for connecting to the pipe segments in the tunnel, a horizontal cross arm is connected to one side of the arc-shaped base, and a diagonal brace connected to the arc-shaped base is provided below the horizontal cross arm; the horizontal cross arm is located in the middle of one side of the arc-shaped base and slightly downward; one end of the prefabricated air duct plate is fixed on the horizontal cross arm.

[0013] Furthermore, a horizontal pad is provided above the horizontal cross arm, and the prefabricated air duct plate is fixed to the horizontal pad and the horizontal cross arm in sequence through fastening connectors; the fastening connectors are connecting bolts and anti-loosening double nuts that can cooperate with them at the other end, and a bolt-fastening steel pad is also provided between the anti-loosening double nut and the horizontal cross arm, and the surfaces of the bolt-fastening steel pad and the horizontal cross arm that contact each other are provided with teeth that can mesh with each other; two steel corbel connectors are arranged parallel to the horizontal pad on each ring of the pipe segment; the steel corbel connector is formed by welding Q355B steel plates, the seams are fully welded, the surface is treated with anti-corrosion and fireproofing, and the cross-section of the horizontal cross arm is U-shaped.

[0014] Compared with the prior art, the present invention adopts a fully assembled rail-top air duct structure design. All components can be prefabricated in the factory. The prefabricated components are produced using ultra-high performance concrete materials with high strength and good durability. Compared with general cast-in-place structures, the thickness can be greatly reduced and materials can be saved. In the present invention, all joint components are connected and fixed by bolts and sleeves, which are easy to install and reliable to connect, avoiding the damage to the segment structure caused by drilling and embedding reinforcement in the traditional cast-in-place method. In the present invention, each component is easy to replace. After a certain part is damaged, the bolts can be removed for replacement, and good working performance can be maintained at all times. The assembly structure of the present invention is stable, the structural weight is reasonable, the connection reliability is high, it can withstand the air pressure when the train is running at high speed, and it has good safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0016] Figure 1 It is a cross-sectional schematic diagram of the arrangement of the assembled rail-top air duct in the shield tunnel station;

[0017] Figure 2 It is a structural schematic diagram of the prefabricated air duct plate in the present invention;

[0018] Figure 3 It is a structural schematic diagram of a prefabricated vertical partition wall in the present invention;

[0019] Figure 4 It is a structural schematic diagram of a π-type connector in the present invention;

[0020] Figure 5 It is a structural schematic diagram of the steel corbel connector of the present invention;

[0021] Figure 6 It is a structural schematic diagram of the T-shaped sleeve embedded in the pipe segment and the sleeve embedded in the component in the present invention;

[0022] Figure 7 It is a schematic diagram of the connection between the anti-loosening double nut and the structural member in the present invention;

[0023] Figure 8 It is a structural schematic diagram of the longitudinal connecting plate in the present invention;

[0024] Fig. 9 It is a structural schematic diagram of the horizontal pad in the present invention;

[0025] Fig.10 It is a schematic diagram of the vertical connection joint between the rail top air duct structure of the single-ring segment and the segment of the present invention;

[0026] Fig.11It is a schematic diagram of the horizontal connection joint between the rail top air duct structure of the single-ring segment and the segment of the present invention;

[0027] Fig.12 It is a schematic diagram of the assembly and connection of various structural parts of the assembled rail top air duct structure of the present invention;

[0028] Fig.13 It is a schematic diagram of the structure of the assembled rail top air duct in the shield tunnel of the present invention;

[0029] Fig.14 It is a structural schematic diagram of the assembled rail-top air duct structure in the shield tunnel of the present invention under application state.

[0030] in,

[0031] 1 Prefabricated air duct board 2 Prefabricated vertical partition wall

[0032] 3π type connector 4 steel bracket connector

[0033] 5T-type sleeve 6 embedded sleeve

[0034] 7 Connecting bolts 8 Arc base

[0035] 9 vertical drop arm 10 horizontal cross arm

[0036] 11 diagonal brace 12 strip bolt hole

[0037] 13 longitudinal connecting plate 14 horizontal pad

[0038] 15 tooth grooves 16 segment rings

[0039] 17 anti-loosening double nut 18 bolts fasten the steel plate DETAILED DESCRIPTION

[0040] In order to better understand the present invention, the present invention is described in detail below in conjunction with specific drawings. The technical terms used in the following description have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The accompanying drawings are provided to clearly describe the preferred embodiments of the present invention in detail, but do not represent the only implementation methods of the present invention. The detailed structural changes made by those skilled in the art without departing from the specific implementation methods should also be considered within the scope disclosed in the present embodiment.

[0041] Figure 1It is a cross-sectional schematic diagram of the arrangement of the assembled rail-top air duct of the present invention in the shield tunnel station. The air duct structure of the present invention is fixed to the top of the shield tunnel and is fixedly connected by a T-type sleeve 5. In a specific embodiment, the inner diameter of the shield tunnel segment lining is 7.7m, the outer diameter is 8.5m, and the width is 1.5m. The block division method of "1 capping block (F) + 2 adjacent blocks (L1, L2) + 4 standard blocks (B1, B2, B3, B4)" is adopted, and the air duct structure is connected to the adjacent block L2 and the standard block B4 respectively. The duct structural components include a prefabricated duct plate 1, a prefabricated vertical partition wall 2, a π-type connector 3 and a steel corbel connector 4. The prefabricated duct plate 1 is horizontally arranged, and the prefabricated vertical partition wall 2 is vertically assembled above the prefabricated duct plate 1. The π-type connector 3 is assembled above the prefabricated vertical partition wall 2 and is used to connect with the adjacent block L2. The steel corbel connector 4 is assembled at one end of the prefabricated duct plate 1 and is used to connect with the standard block B4.

[0042] like Figure 2 As shown, the prefabricated air duct plate 1 is L-shaped and made of UHPC ultra-high performance concrete material, which has high strength and good durability. The thickness of the L-shaped long side is only 1 / 3 to 1 / 2 of the general cast-in-place rail top air duct structure, which can greatly reduce the deadweight of the structure. The L-shaped short side is partially thickened for installing the shielding door. The L-shaped short side design for installing the shielding door can be combined with the shielding door to provide auxiliary support for the air duct structure to maintain the overall stability of the air duct structure. An embedded sleeve 6 is also provided in the L-shaped long side for later bolt connection, wherein four embedded sleeves 6 are embedded at the connection with the steel bracket connector 4, and six embedded sleeves 6 are embedded at the connection with the prefabricated vertical partition wall 2. As an optimized size design, the length of the L-shaped long side of the prefabricated air duct plate 1 is 3520mm+550mm, the longitudinal width along the tunnel is 1496mm, 4mm manufacturing and assembly error is reserved, and the thickness is 70mm. The embedded sleeve 6 can be an M16 sleeve.

[0043] like Figure 3 As shown, the prefabricated vertical partition wall 2 is in an inverted T shape and is made of UHPC ultra-high performance concrete material. The thickness of the long side of the T shape is only 1 / 3 to 1 / 2 of the general cast-in-place rail-top air duct structure, which can greatly reduce the deadweight of the structure. The short side of the T shape is appropriately thickened, and embedded sleeves 6 are also provided in the long side and short side of the T shape for later bolt connection. Six embedded sleeves 6 are embedded at the connection with the π-type connector 3, and six embedded sleeves 6 are embedded at the connection with the prefabricated air duct plate 1. As an optimized size design, the inverted T-shaped prefabricated vertical partition wall 2 has a height of 1610mm, a width of 330mm on the short side of the T shape, a longitudinal length of 1496mm along the tunnel, a 4mm manufacturing and assembly error is reserved, and a thickness of 60mm. The embedded sleeve 6 can be an M16 sleeve.

[0044] like Figure 4As shown, the π-type connector 3 is formed by welding Q355B steel plate, the seams are fully welded, and the surface is treated with anti-corrosion and fireproofing, with high strength and good durability. The π-type connector 3 includes an arc-shaped base 8, a group of vertical vertical walls 9 are arranged below the arc-shaped base 8, and diagonal braces 11 connected to the arc-shaped base 8 are arranged on both sides of the vertical vertical walls 9 to increase the bending and tensile resistance of the connector. The vertical vertical wall 9 is located in a position slightly biased to one side in the middle part below the arc-shaped base 8. A strip bolt hole 12 is provided on the arc-shaped base 8, and the center of the strip bolt hole 12 basically corresponds to the position of the embedded T-shaped sleeve 5 in the pipe segment. The hole position displacement is appropriately adjusted during installation, and it is fixed by connecting bolts 7 to achieve accurate connection of the π-type connector 3 on the pipe segment. The vertical wall 9 is also provided with a strip bolt hole 12, and the center of the strip bolt hole basically corresponds to the position of the embedded sleeve 6 in the prefabricated vertical partition wall. During installation and construction, it can be accurately positioned by adjusting up and down, and then the prefabricated vertical partition wall 2 is fixedly connected to the π-type connector 3 by the connecting bolt 7. In order to further improve the connection stability of the prefabricated vertical partition wall 2 on the π-type connector 3, a longitudinal connecting plate 13 is added on the outer side of the vertical wall 9, and a circular bolt hole is provided on the longitudinal connecting plate 13. When installing the prefabricated vertical partition wall 2, the connecting bolt 7 passes through the bolt hole of the longitudinal connecting plate, the strip bolt hole 12 on the vertical arm of the connector, and the embedded sleeve 6 in the component in sequence, and then is tightened and fixed in place. Matching tooth grooves 15 are also provided on the contacting surfaces of the vertical wall 9 and the longitudinal connecting plate 13, and the locking of the position is ensured by the meshing of the tooth grooves. As an optimized size design, the steel plate thickness of the π-type connector 3 is 15 mm, the diameter of the strip bolt hole 12 is 18 mm, and the hole length is 36 mm. The error can be adjusted during installation to achieve accurate positioning of the partition wall.

[0045] like Figure 5As shown, the steel corbel connector 4 is also welded and formed by Q355B steel plate, the seams are fully welded, the surface is treated with anti-corrosion and fireproofing, and has high strength and good durability. The steel corbel connector 4 includes an arc-shaped base 8, one side of the arc-shaped base 8 is connected to a horizontal cross arm 10, and a diagonal brace 11 connected to the arc-shaped base 8 is provided on the lower side of the horizontal cross arm 10, which is used to provide a stable support for the horizontal cross arm 10. The arc-shaped base 8 in the steel corbel connector 4 has the same structure as the arc-shaped base 8 on the π-shaped connector 3, and can be regarded as the same structural component applied to different structural members. The arc-shaped base 8 of the steel corbel connector is also provided with a strip bolt hole 12 for connection and fixation with the pipe segment. The horizontal cross arm 10 is also provided with a plurality of strip bolt holes 12, the center of which corresponds to the position of the embedded sleeve 6 in the prefabricated air duct plate. During installation and construction, it can be accurately positioned by adjusting left and right, and then the prefabricated air duct plate is fixed by connecting bolts 7. The horizontal cross arm 10 is made of U-shaped channel steel, which can improve the erection stability and structural rigidity. In order to further improve the connection stability, a horizontal pad 14 is added between the prefabricated air duct plate 1 and the steel corbel connector. The horizontal pad 14 is provided with circular bolt holes for bolt connection, and at least two steel corbel connectors are arranged on each ring of the pipe segment. The diagonal brace 11 of the steel corbel connector 4 can be the same as the diagonal brace 11 of the π-type connector 3, and can be regarded as the same structural component applied to different structural members, or it can be different. For example, the diagonal brace 11 of the steel corbel connector 4 can be integrally formed with the horizontal cross arm 10, and can have a variety of implementation methods through conventional means, and it is easy to understand and will not be repeated. As an optimized size design, the steel plate thickness of the steel corbel connector 4 is 15mm. The strip bolt holes 12 on each structural member in the present invention can have the same structure and size, or different sizes can be set as needed, but they can all serve the purpose of adjusting errors and precise positioning.

[0046] like Figure 6 As shown, the embedded T-shaped sleeve 5 in the pipe segment has a large limiting end plate and an external coarse thread structure, which can increase the bonding and anchoring force between the concrete and prevent it from coming out. The two ends of the embedded sleeve 6 are not blocked and have an internal straight thread structure. The T-shaped sleeve 5 can be arranged in two rows along the longitudinal direction of the tunnel, with 57 sleeves in each row along the circumferential direction. The number of embedded sleeves can also be determined according to the needs of the joint connection to ensure the installation of the air duct structure.

[0047] like Figure 7 As shown, in order to prevent the joint bolts from loosening or falling off under the action of long-term train vibration load, a double anti-loosening nut 17 that cooperates with the connecting bolts can be set at the connection, and a fastening steel pad 18 can be added between the anti-loosening double nut 17 and the prefabricated component to make the connection more reliable. Tooth grooves 15 can also be set on the surface of the fastening steel pad 18 and the structural member in contact with it.

[0048] like Figure 8As shown, the longitudinal connecting plate 13 is made of Q355B steel plate, which is designed as an optimized size with a length of 750mm, a width of 80mm and a thickness of 10mm. During installation and construction, the longitudinal connecting plates 13 on both sides of the vertical drop arm 9 are tightened by screwing in the connecting bolts 7 and the anti-loosening double nuts 17, and at the same time, the teeth and grooves are meshed to form a whole, thereby increasing the stress stability of the joint.

[0049] like Fig. 9 As shown, the horizontal pad 14 is made of Q355B steel plate, which is designed as an optimized size with a thickness of 10 mm. The design of the horizontal pad 14 can increase the contact area between the prefabricated air duct plate and the steel bracket connector, avoid stress concentration damage at the connection part, and improve the reliability of the joint.

[0050] Figure 10-14 The schematic diagrams of the structure of the air duct structure of the present invention are shown respectively. During the construction of the air duct structure, the top π-shaped connector 3 is first installed, the prefabricated vertical partition wall 2 is inserted vertically, and the bolts are tightened after accurate positioning, and then the steel bracket connector 4 is installed, and the prefabricated air duct plate 1 is lifted to the installation height and pushed into the tunnel longitudinally. After adjusting the positioning, the joint bolts are connected in sequence to realize the assembly of the whole structure.

[0051] The present invention aims at the disadvantage that the traditional cast-in-place method is used to set the rail-top air duct structure in the shield tunnel, which requires drilling and embedding of reinforcement bars and damages the structure. The present invention proposes a rail-top air duct structure with a fully assembled design. Through prefabricated concrete components and assembled connectors, sleeves (5, 6) are embedded in the pipe segments and prefabricated components, and then assembled by bolt connection. All parts of the assembled rail-top air duct structure of the present invention are prefabricated in the factory and transported to the site for assembly. It is easy to install, can speed up the construction speed and shorten the construction period, has high material strength and good durability, and is easy to repair and replace during the operation stage.

[0052] 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 shield tunnel assembled track top air duct structure, comprising a prefabricated air duct plate (1), a prefabricated vertical partition wall (2), a π-shaped connector (3) and a steel bracket connector (4), wherein the prefabricated air duct plate (1) is arranged horizontally, the prefabricated vertical partition wall (2) is vertically assembled above the prefabricated air duct plate (1), the π-shaped connector (3) is assembled above the prefabricated vertical partition wall (2) and is used to connect with the pipe segment in the tunnel, and the steel bracket connector (4) is assembled at one end of the prefabricated air duct plate (1) and is used to connect with the pipe segment in the tunnel; The π-shaped connector (3) comprises an arc-shaped base (8) for connecting with the pipe segment, a vertical wall (9) is arranged below the arc-shaped base (8), and the vertical wall (9) is connected to the arc-shaped base (8) by a diagonal brace (11) to increase the structural force; the vertical wall (9) is located at a position slightly biased to one side in the middle part below the arc-shaped base (8); the prefabricated vertical partition wall (2) can be inserted and fixed between the vertical walls (9); A longitudinal connecting plate (13) is provided on the outer side of the vertical wall (9), and the prefabricated vertical partition wall (2) is clamped and fixed between the vertical wall (9) and the longitudinal connecting plate (13) by means of a fastening connector; tooth grooves (15) capable of meshing with each other are provided on the surfaces of the vertical wall (9) and the longitudinal connecting plate (13) that contact each other; the fastening connector is a connecting bolt (7) and a double anti-loosening nut (17) capable of cooperating with the bolt at the other end; a strip bolt hole (12) capable of adjusting the error is provided on the vertical wall (9); two π-type connecting pieces (3) are arranged in parallel along the longitudinal connecting plate on each ring segment; the π-type connecting piece (3) is welded and formed by Q355B steel plate, the seam is fully welded, and the surface is treated with anti-corrosion and fireproofing; The steel bracket connector (4) comprises an arc-shaped base (8) for connecting with a pipe segment in a tunnel, a horizontal cross arm (10) is connected to one side of the arc-shaped base (8), and a diagonal brace (11) connected to the arc-shaped base (8) is provided on one side below the horizontal cross arm (10); the horizontal cross arm (10) is located at a position slightly deviated downward from the middle of one side of the arc-shaped base (8); one end of the prefabricated air duct plate (1) is fixed on the horizontal cross arm (10); A horizontal pad (14) is arranged above the horizontal cross arm (10), and the prefabricated air duct plate (1) is fixed to the horizontal pad (14) and the horizontal cross arm (10) in sequence through fastening connectors; the fastening connectors are connecting bolts (7) and anti-loosening double nuts (17) that can cooperate with the connecting bolts at the other end; a bolt-fastening steel pad (18) is also arranged between the anti-loosening double nuts (17) and the horizontal cross arm (10); and teeth (15) that can mesh with each other are arranged on the surfaces of the bolt-fastening steel pad (18) and the horizontal cross arm (10) that contact each other; two steel bracket connectors (4) are arranged in parallel along the horizontal pad on each ring of the pipe segment; the steel bracket connector (4) is formed by welding Q355B steel plates, the seams are fully welded, and the surface is treated with anti-corrosion and fireproofing, and the cross section of the horizontal cross arm (10) is U-shaped.

2. The shield tunnel assembled rail top air duct structure according to claim 1 is characterized in that: The π-shaped connector (3) and the steel bracket connector (4) are provided with strip-shaped bolt holes (12) capable of adjusting errors; and a T-shaped sleeve (5) for connection is pre-buried in the tunnel segment.

3. The shield tunnel assembled rail top air duct structure according to claim 1 is characterized in that: The prefabricated air duct plate (1) is L-shaped and made of UHPC ultra-high performance concrete material. The thickness of the L-shaped long side is 1 / 3 to 1 / 2 of the general cast-in-place rail top air duct structure, and the L-shaped short side is locally thickened for installing the shielding door. The prefabricated air duct plate (1) is provided with an embedded sleeve (6) for connecting to the prefabricated vertical partition wall (2) and the steel bracket connector (4) respectively.

4. The shield tunnel assembled rail top air duct structure according to claim 1, characterized in that: The prefabricated vertical partition wall (2) is in an inverted T-shape and is made of UHPC ultra-high performance concrete material. The thickness of the long side of the T-shape is 1 / 3 to 1 / 2 of that of a general cast-in-place rail-top air duct structure, and the short side of the T-shape is partially thickened. The prefabricated vertical partition wall (2) is provided with an embedded sleeve (6) for connecting to the π-shaped connector (3) and the prefabricated air duct plate (1) respectively.

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