A box-shaped fully prefabricated concrete track top air duct and construction method

Abstract

The present invention belongs to the field of track-top air ducts, and particularly relates to a box-shaped fully prefabricated concrete track-top air duct and a construction method. The track-top air duct comprises a plurality of air duct unit sections, and adjacent air duct unit sections are connected by an inter-section connection section formed by secondary casting with a unit section mold. The air duct unit sections are integrally prefabricated and produced in a factory and installed on site. One air duct unit section includes a left side wall panel, a right side wall panel, a top wall panel, a bottom wall panel and a corner node area connecting adjacent wall panels. The left side wall panel, the right side wall panel, the top wall panel and the bottom wall panel are flat plate structures prefabricated with reinforced concrete, and the corner node area is cast in situ with a corner mold. The construction method includes a factory prefabrication step of the air duct unit section and a site installation step of the air duct unit section. The mold used for the corner node area of the present invention is simple, low in cost and strong in versatility. The installation and construction speed of the present invention is fast, and the connection integrity is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of track top air ducts, and particularly relates to a box-shaped fully prefabricated concrete track top air duct and a construction method thereof. Background Art

[0002] The track top air duct, that is, the top exhaust air duct of the train, as an internal component of the subway station, is suspended at the intersection of the middle slab and the structural side wall. The position where the track top air duct is located is special, and it is generally not cast simultaneously with the main structure. Especially in the stations where shield construction needs to pass through, the track top air duct must be cast later, which often takes up the time for later mechanical and electrical installation and decoration, directly affecting the trial operation and opening of the whole line. Moreover, due to the narrow construction space for the later-cast track top air duct, it is not easy to ensure the construction quality. Therefore, at present, precast track top air ducts are usually used to replace the traditional cast-in-place reinforced concrete track top air ducts.

[0003] When producing traditional precast components of track top air ducts (precast track top air duct units), one method is to first make a cylindrical steel reinforcement cage, and then use a mold with an overall shape of a loop to cast the track top air duct integrally. However, since the inside of the precast track top air duct unit is an irregular rectangle (with chamfers provided at the corners), it is necessary to customize the mold during production. Another method is to separately make precast air duct plates on three or four sides, and then connect the precast air duct plates with bolts to form a whole. But this requires leaving bolt connection holes on the mold and the precast air duct plates, making the process of mold making and precast plate casting of the track top air duct relatively complex, requiring customizing the mold and having relatively high detailed requirements for the customized mold. And due to the different sizes of precast air duct segments in different engineering examples, the precast molds cannot be reused, which results in expensive precast molds and increased overall costs.

[0004] In view of this, research and improvement are carried out on the existing structure and deficiencies to provide a new type of assembled track top air duct structure, mold and construction plan for underground stations, in order to achieve the purpose of reducing the production cost of track top air ducts. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a box-shaped fully prefabricated concrete track top air duct and a construction method thereof, so as to solve the problems in the overall construction of existing precast track top air ducts, such as high mold production cost, long cycle, low turnover utilization rate of finished precast track top air duct molds, and difficulties in overall connection and sealing of track top air ducts.

[0006] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0007] A box-shaped fully prefabricated concrete track top air duct includes several air duct unit sections, and adjacent air duct unit sections are connected by an inter-joint connection section formed by secondary casting with a unit section mold; one air duct unit section includes a left side wall panel, a right side wall panel, a top wall panel, a bottom wall panel, and a corner node area connecting adjacent wall panels. The left side wall panel, right side wall panel, top wall panel, and bottom wall panel are reinforced concrete precast flat structures, and the corner node area is cast in situ with a corner mold; the corner mold includes an L-shaped corner outer mold and a special-shaped corner inner mold, and the position of the corner inner mold corresponding to the corner of the corner outer mold is provided with a chamfer; when casting the corner node area, the long sides on both sides of the corner mold are detachably connected to the adjacent left side wall panel, right side wall panel, top wall panel, or bottom wall panel.

[0008] Furthermore, corner mold reserved holes are provided at the long sides on both sides of the corner outer mold and the corner inner mold, and corresponding wall panel reserved holes are provided on the left side wall panel, right side wall panel, top wall panel, and bottom wall panel corresponding to the corner mold reserved holes; before casting the corner node area, the corner mold is installed by bolts passing through the corner mold reserved holes and the wall panel reserved holes.

[0009] Furthermore, the left side wall panel and the right side wall panel are of the same size and structure, and the top wall panel and the bottom wall panel are of the same size and structure;

[0010] The vertical steel bars in the left side wall panel and the right side wall panel are anchored into the corner node area in a U-shaped form at the lower part, and the vertical steel bars pass through the core area of the corner node at the upper part and form suspension bars in a bent manner; the horizontal steel bars in the top wall panel and the bottom wall panel are anchored into the corner node area in a U-shaped form at the ends.

[0011] Furthermore, stress longitudinal bars, construction longitudinal bars, and construction bars are also provided in the corner node area; the stress longitudinal bars longitudinally penetrate the left side wall panel, the right side wall panel, the top wall panel, and the bottom wall panel and are anchored into the U-shaped steel bar part of the corner node area, the construction bars are arranged corresponding to the chamfer of the corner node area, and the construction longitudinal bars are longitudinally fixed on the construction bars.

[0012] Furthermore, concave shear resistance grooves for enhancing the connection with the concrete cast in the corner node area are respectively formed on the upper and lower end faces of the left side wall panel and the right side wall panel, and the left and right end faces of the top wall panel and the bottom wall panel.

[0013] Furthermore, concave grouting grooves are respectively formed on the front and rear end faces of the left side wall panel, the right side wall panel, the top wall panel, and the bottom wall panel.

[0014] Furthermore, a terminal sleeve is pre-embedded at the rear end of the corner node area, and a starting steel bar aligned with the terminal sleeve is pre-embedded at the front end of the corner node area. The front end of the starting steel bar extends forward out of the corner node area. When two adjacent air duct unit sections are connected, the starting steel bar is inserted into the terminal sleeve.

[0015] Furthermore, the distance between adjacent air duct unit sections is 9 - 11 mm. The unit section mold includes an outer unit section mold and an inner unit section mold. The widths of the outer unit section mold and the inner unit section mold are 100 - 120 mm. The outer unit section mold and the inner unit section mold are connected by tie bolts arranged in the middle, and sealing rubber strips are arranged at the front and rear edges of the outer unit section mold and the inner unit section mold.

[0016] Furthermore, support reserved screw holes are arranged on the outer sides of the left side wall panel, the right side wall panel, the top wall panel, and the bottom wall panel. The support reserved screw holes are used to connect lateral supports during assembly.

[0017] The present invention also provides a construction method for the above-mentioned box-shaped fully prefabricated concrete track roof air duct, including a factory prefabrication step of the air duct unit section and a site installation step of the air duct unit section.

[0018] The factory prefabrication step of the air duct unit section includes:

[0019] S11: Prefabricate the left side wall panel, the right side wall panel, the top wall panel, and the bottom wall panel, number them according to the air duct unit section, and transport them to the assembly site.

[0020] S12: Install lateral supports on the left side wall panel, the right side wall panel, the top wall panel, and the bottom wall panel.

[0021] S13: Take the left side wall panel, the right side wall panel, the top wall panel, and the bottom wall panel of an air duct unit section, place their rear ends on a flat ground, with the front ends facing upwards, and assemble them in sequence.

[0022] S14: Install the steel bars in the corner node area, install the terminal sleeve at the rear end of the corner node area, and install the starting steel bar at the front end of the corner node area.

[0023] S15: Install the corner mold. After installation, conduct a overall measurement and fine adjustment.

[0024] S16: Pour the corner node area with slightly expanded self-compacting concrete and cure for more than 7 days.

[0025] S17: Remove the corner mold and lateral supports, and protect the finished air duct unit section.

[0026] The site installation step of the air duct unit section includes:

[0027] S21: Transport the air duct unit section to the installation site;

[0028] S22: Use a tower crane to hoist the air duct unit section onto the track top air duct assembly platform;

[0029] S23: Start installing the air duct unit section from one end, with a spacing of 9 - 11 mm between adjacent air duct unit sections; Insert the starting steel bars reserved in the previous air duct unit section into the end sleeves reserved in the next air duct unit section;

[0030] S25: After installation, conduct a comprehensive measurement and fine adjustment;

[0031] S26: Install the unit section mold, and secondary - pour micro - expanded cement slurry at the joints of adjacent air duct unit sections to seal the gaps between the starting steel bars and the end sleeves, as well as the joints of the air duct unit sections. After curing, remove the unit section mold.

[0032] The beneficial effects of the present invention are:

[0033] The air duct unit section of the present invention is constructed by factory prefabrication and assembly. Each wall panel is small in volume and light in weight, and is made by traditional methods, which is convenient for construction and has a fast construction speed; The four - sided wall panels are connected into one body through the corner node areas made by pouring; The molds used in the corner node areas are simple and low - cost, and can be adapted to the production of track top air ducts of various sizes, with strong versatility; Moreover, the processing method of pre - fabricating the wall panels first and then making the overall air duct unit section has the advantages of simple construction and low cost compared with the conventional overall pre - fabrication in addition to ensuring the quality of the product itself;

[0034] The air duct unit sections of the present invention are connected by secondary pouring, with mature technology, simple molds, simple connection construction, fast construction speed, and good connection integrity; It can avoid air leakage and poor durability of the track top air duct. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The schematic drawings forming a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. Among them:

[0036] Figure 1 is a schematic structural diagram of the track top air duct after installation according to an embodiment of the present invention.

[0037] Figure 2 is a sectional view of the air duct unit section according to an embodiment of the present invention.

[0038] Figure 3 is a schematic front - view structure diagram of the left - hand side wall panel according to an embodiment of the present invention.

[0039] Figure 4 is Figure 3Cross-sectional view of the left side wall panel in

[0040] Figure 5 is Figure 3 Cross-sectional view of the left side wall panel in

[0041] Figure 6 Front view structural schematic diagram of the top wall panel of the embodiment of the present invention.

[0042] Figure 7 is Figure 6 Cross-sectional view of the top side wall panel in

[0043] Figure 8 is Figure 6 Cross-sectional view of the top side wall panel in

[0044] Figure 9 Schematic diagram of the processing process of the air duct unit section of the embodiment of the present invention.

[0045] Figure 10 Structural schematic diagram of the unit section connection mold of the embodiment of the present invention.

[0046] Figure 11 Reinforcement structure diagram of the corner node area of the embodiment of the present invention.

[0047] Figure 12 Cross-sectional view of the corner mold of the embodiment of the present invention.

[0048] In the figure: 1 - left side wall panel, 2 - right side wall panel, 3 - top wall panel, 4 - bottom wall panel, 5 - corner node area, 11 - side plate U-shaped steel bar, 12 - suspension bar, 13 - side plate shear-resistant groove, 14 - side plate grouting groove, 15 - side plate grouting hole, 16 - side plate slurry outlet hole, 17 - side plate support reserved hole, 18 - lateral support, 19 - side plate reserved hole, 31 - top plate U-shaped steel bar, 32 - top plate reserved hole, 33 - top plate shear-resistant groove, 34 - top plate grouting groove, 35 - top plate grouting hole, 36 - top plate slurry outlet hole, 37 - top plate support reserved hole, 41 - outer corner mold, 411 - outer corner mold reserved hole, 42 - inner corner mold, 421 - inner corner mold reserved hole, 43 - unit section outer mold, 44 - unit section inner mold, 45 - tensioning hole, 46 - tensioning bolt, 51 - end sleeve, 52 - starting end steel bar, 53 - stressed longitudinal bar, 54 - structural longitudinal bar, 55 - structural bar, 100 - air duct unit section, 200 - inter-joint connection section. Detailed implementation manners

[0049] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0050] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0051] For the sake of description, the directions in this embodiment are described according to the Figure 1 front, back, left, right, up, and down directions.

[0052] As Figures 1 to 12 shown, a box-shaped fully prefabricated concrete track-top air duct includes a plurality of air duct unit sections 100, and adjacent air duct unit sections 100 are connected by secondary casting through unit section molds; one air duct unit section 100 includes a left side wall panel 1, a right side wall panel 2, a top wall panel 3, a bottom wall panel 4, and a corner node area 5 connecting adjacent wall panels. The left side wall panel 1, the right side wall panel 2, the top wall panel 3, and the bottom wall panel 4 are flat plate structures precast with reinforced concrete, and the corner node area 5 is cast in situ through a corner mold; the corner mold includes an L-shaped corner outer mold 41 and a special-shaped corner inner mold 42, and the position of the corner inner mold 42 corresponding to the corner of the corner outer mold 41 is set as a chamfer; when casting the corner node area 5, the long sides on both sides of the corner mold are detachably connected to the adjacent left side wall panel 1, right side wall panel 2, top wall panel 3, or bottom wall panel 4.

[0053] After the left side wall panel 1, the right side wall panel 2, the top wall panel 3, and the bottom wall panel 4 of the air duct unit section 100 are prefabricated and produced by the factory, they are assembled in the factory and concrete is poured into the corner node area 5. Finally, the corner node area 5 connects the four wall panels together, and the air duct unit section 100 is thickened at the inner corners, increasing the structural stability of the air duct unit section 100, and finally forming a firm and stable air duct unit section 100; the secondary casting of adjacent air duct unit sections 100 is carried out at the construction site. Among them, the left side wall panel 1, the right side wall panel 2, the top wall panel 3, and the bottom wall panel 4 are prefabricated and produced by using the traditional production method of precast reinforced concrete slabs; the length of each air duct unit section 100 is planned according to the needs of the entire box-shaped fully prefabricated concrete track-top air duct.

[0054] As Figure 2 、 Figure 9 、 Figure 12As shown, the outer corner mold 41 is made of an L-shaped steel plate, and the inner corner mold 42 is made of a special-shaped steel plate; at the two long sides of the outer corner mold 41 and the inner corner mold 42, corner mold reserved holes are provided, namely the outer corner mold reserved hole 411 and the inner corner mold reserved hole 421; on the left side wall plate 1, the right side wall plate 2, the top wall plate 3, and the bottom wall plate 4, wall plate reserved holes corresponding to the corner mold reserved holes are provided; specifically, Figures 3 to 5 the side plate reserved hole 19 is schematically drawn in Figures 6 to 8 and the top plate reserved hole 32 is schematically drawn in. Both the side plate reserved hole 19 and the top plate reserved hole 32 are smooth holes; before pouring the corner joint area 5, the corner mold is installed by bolts passing through the corner mold reserved holes and the wall plate reserved holes, and the corner mold is fixed by tightening the bolts with nuts. After demolding, the wall plate reserved holes are blocked with hole-blocking materials.

[0055] As shown in Figure 1 , Figure 2 , Figure 5 , Figure 10 the left side wall plate 1 and the right side wall plate 2 are of the same size and structure, and the top wall plate 3 and the bottom wall plate 4 are of the same size and structure;

[0056] As shown in Figures 2 to 7 the vertical steel bars in the left side wall plate 1 and the right side wall plate 2 are anchored into the corner joint area 5 in a U-shaped form at the lower part, denoted as the side plate U-shaped steel bar 11, and the vertical steel bars of the left side wall plate 1 and the right side wall plate 2 pass through the corner joint core area at the upper part and form suspension bars 12 in a bent manner; the horizontal steel bars in the top wall plate 3 and the bottom wall plate 4 are anchored into the corner joint area 5 in a U-shaped form at the ends, denoted as the top plate U-shaped steel bar 31. As shown in Figure 2 , Figure 9 when prefabricating the left side wall plate 1 and the right side wall plate 2, suspension bars 12 buried into the middle plate are reserved at the top. Correspondingly, through holes for the suspension bars 12 to pass through are reserved on the two outer corner molds 41 of the air duct unit section 100; the diameter of the through holes is slightly larger than that of the suspension bars 12. When the concrete of the corner mold is poured, the gap between the through holes and the suspension bars 12 is naturally compacted.

[0057] As shown in Figure 11As shown, longitudinal stress-bearing reinforcement bars 53, longitudinal construction reinforcement bars 54 and construction reinforcement bars 55 are also arranged in the corner node area 5. The longitudinal stress-bearing reinforcement bars 53 longitudinally penetrate through the left side wall panel 1, the right side wall panel 2, the top wall panel 3 and the bottom wall panel 4 and are anchored into the U-shaped steel bar part of the corner node area 5. The construction reinforcement bars 55 are arranged corresponding to the chamfer of the corner node area 5, and the longitudinal construction reinforcement bars 54 are longitudinally fixed on the construction reinforcement bars 55. Specifically, the diameter of the construction reinforcement bars 55 is 8 mm and the spacing is 200 mm; there are 3 longitudinal construction reinforcement bars 54 with a diameter of 8 mm; there are 8 longitudinal stress-bearing reinforcement bars 53, among which four longitudinal stress-bearing reinforcement bars 53 are arranged in the area surrounded by the U-shaped parts of the steel bars of the left side wall panel 1 / right side wall panel 2 and the U-shaped parts of the top wall panel 3 / bottom wall panel 4, and the other two longitudinal stress-bearing reinforcement bars 53 are fixed on the U-shaped parts of the steel bars of the left side wall panel 1 / right side wall panel 2, and the other two longitudinal stress-bearing reinforcement bars 53 are fixed on the U-shaped parts of the top wall panel 3 / bottom wall panel 4.

[0058] Concave shear resistance grooves for enhancing the connection with the concrete poured in the corner node area 5 are respectively formed on the upper and lower end faces of the left side wall panel 1 and the right side wall panel 2 and the left and right end faces of the top wall panel 3 and the bottom wall panel 4. The shear resistance grooves are used to enhance the connection between the wall panel and the concrete in the corner node area 5. Concave grouting grooves are respectively formed on the front and rear end faces of the left side wall panel 1, the right side wall panel 2, the top wall panel 3 and the bottom wall panel 4. After the grouting grooves are filled with concrete slurry, the connection gaps between the air duct unit joints 100 can be sealed. The cross-sections of the shear resistance grooves and the grouting grooves are trapezoidal, rectangular or semi-circular. Figures 3 to 5 In the left side wall panel 1 shown in the figure, the side panel shear resistance groove 13 and the side panel grouting groove 14 are schematically drawn. Corresponding to the side panel grouting groove 14, a side panel grouting hole 15 and a side panel slurry outlet hole 16 are also arranged on the left side wall panel 1 for injecting slurry into the space between adjacent air duct unit joints 100 when adjacent air duct unit joints 100 are connected. Figures 6 to 7 In the top wall panel 3 shown in the figure, the top panel shear resistance groove 33 and the top panel grouting groove 34 are schematically drawn; corresponding to the top panel grouting groove 34, a top panel grouting hole 35 and a top panel slurry outlet hole 36 are also arranged on the left side wall panel 1. One ends of the side panel grouting hole 15, the side panel slurry outlet hole 16, the top panel grouting hole 35 and the top panel slurry outlet hole 36 are opened on the outer side surface of the wall panel, and the other ends are directed towards the shear resistance groove or the grouting groove.

[0059] As Figure 1 、 Figures 9 to 11As shown, a terminal sleeve 51 is pre-embedded at the rear end of the corner node area 5, and a starting steel bar 52 aligned with the terminal sleeve 51 is pre-embedded at the front end of the corner node area 5. The front end of the starting steel bar 52 extends forward out of the corner node area 5. When two adjacent air duct unit sections 100 are connected, the starting steel bar 52 is inserted into the terminal sleeve 51, and the annular gap between the starting steel bar 52 and the terminal sleeve 51 can be filled by the solidification of the slightly expanding cement slurry flowing in from the space between the air duct unit sections 100. Figure 1 , Figure 10 The installation schematic diagram of the starting steel bar 52 and the terminal sleeve 51 is schematically drawn in

[0060] As Figure 1 , Figure 10 shown, the distance between two adjacent air duct unit sections 100 is 9 - 11 mm, preferably 10 mm. The unit section mold includes an outer unit section mold 43 and an inner unit section mold 44. The widths of the outer unit section mold 43 and the inner unit section mold 44 are 100 - 120 mm. The outer unit section mold 43 and the inner unit section mold 44 are connected by a tension bolt 46 arranged in the middle. Sealing rubber strips are arranged at the front and rear edges of the outer unit section mold 43 and the inner unit section mold 44. The slightly expanding cement slurry after secondary pouring solidifies to form an inter-joint connection section 200, forming a structural seal for the connection gap between the air duct unit sections 100. Specifically, the outer unit section mold 43 is made of a 100-mm-wide rectangular steel plate strip, and a tension hole 45 for the tension bolt 46 to pass through is reserved in the middle. The inner unit section mold 44 is made of a 100-mm-wide special-shaped steel plate, and a tension hole 45 for the tension bolt 46 to pass through is also reserved in the middle.

[0061] As Figure 3 , Figure 6 shown, support reserved screw holes are arranged on the outer sides of the left side wall plate 1, the right side wall plate 2, the top wall plate 3, and the bottom wall plate 4. The support reserved screw holes are used to connect the lateral support 18 during assembly. The lateral support 18 is a rod-shaped body that serves as a diagonal brace after the wall plates are erected. Figure 9 In Figure 3 shows the state when the lateral support 18 is used for auxiliary support. Figure 6 shows the side plate support reserved hole 17 arranged on the left side wall plate 1,

[0062] The present invention also provides a construction method for the box-type fully prefabricated concrete track top air duct described above, including the factory prefabrication step of the air duct unit section 100 and the on-site installation step of the air duct unit section 100.

[0063] The factory prefabrication step of the air duct unit section 100 includes:

[0064] S11: Prefabricate the left side wall panel 1, right side wall panel 2, top wall panel 3, and bottom wall panel 4, number them according to the air duct unit section 100, and transport them to the assembly site;

[0065] S12: Install lateral supports 18 on the left side wall panel 1, right side wall panel 2, top wall panel 3, and bottom wall panel 4;

[0066] S13: The assembly sequence of the wall panels of one air duct unit section 100 is to place the rear end of the unit section downward on a flat ground, with the front end upward, and then sequentially assemble the left side wall panel 1, right side wall panel 2, top wall panel 3, and bottom wall panel 4;

[0067] S14: Install the stress-bearing steel bars, structural longitudinal bars 54, and structural bars 55 in the corner node area 5; install the end sleeve 51 at the rear end of the corner node area 5, and install the starting-end steel bar 52 at the front end of the corner node area 5;

[0068] S15: Install the corner mold. After installation, conduct a overall measurement and fine adjustment;

[0069] S16: Pour the corner node area 5 with slightly expanding self-compacting concrete, vibrate the concrete, and cure for more than 7 days;

[0070] S17: Remove the corner mold and lateral supports 18, and protect the finished product of the air duct unit section 100;

[0071] The on-site installation steps of the air duct unit section 100 include:

[0072] S21: Transport the air duct unit section 100 to the installation site;

[0073] S22: Hoist the air duct unit section 100 to the track-top air duct assembly platform by a tower crane;

[0074] S23: Start installing the air duct unit section 100 from one end. The spacing between adjacent air duct unit sections 100 is 9 - 11 mm; the starting-end steel bar 52 reserved in the previous air duct unit section 100 is inserted into the end sleeve 51 reserved in the next air duct unit section 100;

[0075] S25: After installation, conduct a overall measurement and fine adjustment;

[0076] S26: Install the unit section mold, and secondary pour slightly expanding cement slurry at the connection of adjacent air duct unit sections 100 to seal the gap between the starting-end steel bar 52 and the end sleeve 51, as well as the connection of the air duct unit sections 100. After curing, remove the unit section mold.

[0077] In the present invention, the prefabricated air duct unit section 100 is prefabricated in the factory. During prefabrication, first, each wall panel is prefabricated, and then after connecting each wall panel with a corner mold, self-compacting concrete is poured in the corner mold to connect the four wall panels into a whole. Each wall panel is small in volume and light in weight, and the corner mold is easy to manufacture and use. Compared with the conventional overall prefabrication method of the track top air duct, it has the advantages of simple construction, low cost, and good quality.

[0078] When installing the air duct unit section on site, a slightly expanding cement slurry is secondarily poured between two adjacent air duct unit sections 100 by using a unit section mold. After it cures, an inter-joint connection section is formed, making the connection between two adjacent air duct unit sections 100 dense, which can avoid air leakage and good durability of the track top air duct.

[0079] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A box-shaped fully prefabricated concrete track roof air duct, characterized in that: It includes several air duct unit sections (100), the distance between adjacent air duct unit sections (100) is 9 - 11 mm, and adjacent air duct unit sections (100) are connected by an inter - section connection section (200) formed by secondary casting with a unit section mold; one air duct unit section (100) includes a left side wall panel (1), a right side wall panel (2), a top wall panel (3), a bottom wall panel (4), and a corner node area (5) connecting adjacent wall panels. The left side wall panel (1), the right side wall panel (2), the top wall panel (3), and the bottom wall panel (4) are reinforced concrete precast flat structures, and the corner node area (5) is cast - in - place with a corner mold; the corner mold includes an L - shaped outer corner mold (41) and a special - shaped inner corner mold (42), and the position of the inner corner mold (42) corresponding to the corner of the outer corner mold (41) is set as a chamfer; when casting the corner node area (5), the long sides on both sides of the corner mold are detachably connected to the adjacent left side wall panel (1), right side wall panel (2), top wall panel (3), or bottom wall panel (4). The left side wall panel (1) and the right side wall panel (2) are of the same size and structure, and the top wall panel (3) and the bottom wall panel (4) are of the same size and structure. The vertical steel bars in the left side wall panel (1) and the right side wall panel (2) are anchored into the corner node area (5) in a U - shaped form at the lower part, and the vertical steel bars pass through the core area of the corner node at the upper part and form a suspension bar (12) in a bent manner; the horizontal steel bars in the top wall panel (3) and the bottom wall panel (4) are anchored into the corner node area (5) in a U - shaped form at the ends. Stressed longitudinal bars (53), structural longitudinal bars (54), and structural bars (55) are also arranged in the corner node area (5); the stressed longitudinal bars (53) longitudinally penetrate the left side wall panel (1), the right side wall panel (2), the top wall panel (3), and the bottom wall panel (4) and are anchored into the U - shaped steel bar part of the corner node area (5), the structural bars (55) are arranged corresponding to the chamfer of the corner node area (5), and the structural longitudinal bars (54) are longitudinally fixed on the structural bars (55). The unit section mold includes an outer unit section mold (43) and an inner unit section mold (44), and the widths of the outer unit section mold (43) and the inner unit section mold (44) are 100 - 120 mm; the outer unit section mold (43) and the inner unit section mold (44) are connected by a tension bolt (46) arranged in the middle, and sealing rubber strips are arranged at the front and rear edges of the outer unit section mold (43) and the inner unit section mold (44). The air duct unit section (100) is prefabricated in a factory, and the factory prefabrication steps of the air duct unit section (100) include: S11: Prefabricate the left side wall panel (1), the right side wall panel (2), the top wall panel (3), and the bottom wall panel (4), number them according to the air duct unit section (100), and transport them to the assembly site. S12: Install lateral supports (18) on the left side wall panel (1), the right side wall panel (2), the top wall panel (3), and the bottom wall panel (4). S13: Take the left wall panel (1), the right wall panel (2), the top wall panel (3), and the bottom wall panel (4) of an air duct unit section (100), place their rear ends on a flat ground with their front ends facing upward, and assemble them in sequence; S14: installing the steel bars of the corner node area (5), installing the end sleeve (51) at the rear end of the corner node area (5), and installing the start steel bars (52) at the front end of the corner node area (5); S15: Install the corner mold. After installation, measure and fine-tune the whole mold. S16: Use micro-expansive self-compacting concrete to cast the corner node area (5) and cure for more than 7 days; S17: Remove the corner mold and the lateral support (18) to protect the finished air duct unit section (100).

2. The box-shaped fully prefabricated concrete track top air duct according to claim 1, wherein: Corner mould reserved holes are provided at the long sides of both sides of the corner outer mould (41) and the corner inner mould (42), and wall panel reserved holes corresponding to the corner mould reserved holes are provided on the left wall panel (1), the right wall panel (2), the top wall panel (3), and the bottom wall panel (4); before casting the corner node area (5), the corner mould is installed by means of bolts penetrating the corner mould reserved holes and the wall panel reserved holes.

3. The box-shaped fully prefabricated concrete track roof air duct according to claim 1, characterized in that: The upper and lower end surfaces of the left side wall panel (1) and the right side wall panel (2) and the left and right end surfaces of the top wall panel (3) and the bottom wall panel (4) are respectively formed with concave shear grooves for strengthening the connection with the concrete poured in the corner node area (5).

4. The box-type fully prefabricated concrete track roof air duct according to claim 1, wherein: The front and rear end surfaces of the left wall plate (1), the right wall plate (2), the top wall plate (3) and the bottom wall plate (4) are respectively formed with inwardly concave grouting grooves.

5. The box-shaped fully prefabricated concrete track top air duct according to claim 1, characterized in that: The rear end of the corner node area (5) is pre-embedded with an end sleeve (51), the front end of the corner node area (5) is pre-embedded with a start end steel bar (52) aligned with the end sleeve (51), and the front end of the start end steel bar (52) extends forward from the corner node area (5); when two adjacent air duct unit sections (100) are connected, the start end steel bar (52) is inserted into the end sleeve (51).

6. The box-shaped fully prefabricated concrete track roof air duct according to claim 1, wherein: The left side wall panel (1), the right side wall panel (2), the top wall panel (3), and the bottom wall panel (4) are provided with support reserved screw holes on their outwardly facing sides, and the support reserved screw holes are used to connect the lateral supports (18) during assembly.

7. A construction method for the box-type fully prefabricated concrete track roof air duct according to any one of claims 1 to 6, characterized in that, The method comprises the steps of installing the air duct unit section (100) on site; The on-site installation steps of the air duct unit section (100) include: S21: transporting the air duct unit section (100) to the installation site; S22: hoisting the air duct unit section (100) onto the rail top air duct assembly platform by means of a tower crane; S23: installing the air duct unit section (100) from one end, with the spacing between adjacent air duct unit sections (100) being 9 to 11 mm; inserting the start end steel bar (52) reserved in the previous air duct unit section (100) into the end end sleeve (51) reserved in the next air duct unit section (100); S25: After the installation is completed, the whole is measured and fine-tuned; S26: Install the unit joint mold, and secondary pour the slightly expanding cement slurry at the connection of adjacent air duct unit joints (100) to seal the gap between the starting end steel bars (52) and the end sleeves (51), as well as the connection of the air duct unit joints (100). After curing, remove the unit joint mold.

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