Hanging rail type prefabricated UHPC track top air duct structure

Abstract

The utility model discloses a kind of overhead monorail type prefabricated UHPC rail top air duct structures, including middle plate, and heavy load track is embedded in the bottom surface both sides of middle plate;Heavy load track is fixed with several "U" type air duct segments by pulley block along longitudinal direction, and adjacent "U" type air duct segments are fixedly connected by screw rod through reserved slot hole channel each other;"U" type air duct segment includes air duct side plate, and heavy load pulley block is installed in air duct side plate top and cooperates with heavy load track, and air duct bottom plate is detachably connected in air duct side plate lower part;Air duct bottom plate and air duct side plate are UHPC prefabricated plate.The utility model is hoisted by embedding slide rail and using pulley block to rail top air duct structure, effectively solve the problem that internal operation space of station is limited, and applicability is strong, improve the efficiency and flexibility of air duct installation, reduce construction cost, and reduce the security risk brought by large-scale machinery;UHPC is prepared side plate and bottom plate, reduce the structure deadweight and significantly improve structural strength and durability.

Description

Technical Field

[0001] This utility model belongs to the field of construction, and in particular to a suspended rail type prefabricated UHPC rail top ventilation duct structure. Background Technology

[0002] As a key internal structural component of the ventilation system in subway stations, track-top ventilation ducts are primarily constructed using prefabrication or cast-in-place methods. Cast-in-place construction of track-top ventilation ducts faces numerous limitations in practical engineering applications due to constraints such as limited working space, numerous irregularly shaped formwork, poor controllability of construction quality, and low economic efficiency. Therefore, prefabrication is typically used in practical projects to improve construction efficiency, quality, and economy. However, limited by the properties of ordinary concrete, traditional prefabricated track-top ventilation ducts still suffer from structural defects such as monotonous configuration, excessive weight, susceptibility to damage, and insufficient joint reliability, hindering their further application and development.

[0003] A search of existing literature and technologies revealed that utility model patents such as 201911341313.2, 201910628395.2, 202011533117.8, and 202011076944.9 all disclose a prefabricated rail-top ventilation duct structure and construction method, solving the problems associated with cast-in-place construction methods and reducing installation costs. However, these utility model patents still use ordinary concrete as the material and traditional hoisting and installation methods, and problems such as heavy structural weight, susceptibility to damage, and low construction flexibility and efficiency still exist. Therefore, there is an urgent need to design a lightweight and highly efficient and reliable prefabricated rail-top ventilation duct structure to address the many drawbacks of traditional prefabrication technology. Utility Model Content

[0004] To address the aforementioned problems, this utility model discloses a suspended rail type prefabricated UHPC rail top air duct structure.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows: A prefabricated UHPC rail-top air duct structure with suspended rails includes a middle plate, on both sides of the bottom surface of the middle plate, heavy-duty rails are pre-embedded; several "U"-shaped air duct segments are fixed along the longitudinal direction by pulley blocks, and adjacent "U"-shaped air duct segments are fixedly connected to each other. The "U"-shaped air duct segment includes air duct side plates, each consisting of a left side plate and a right side plate. Heavy-duty pulley blocks that mate with heavy-duty rails are installed on the top of the left and right side plates. Grooves are pre-drilled at both ends of the bottom of the left and right side plates, with threaded through holes along the longitudinal direction. A first screw passes through these threaded through holes to securely connect adjacent "U"-shaped air duct segments. A bottom plate is detachably connected to the lower part of the left and right side plates. The bottom plate, left side plate, and right side plate are all UHPC precast panels. The heavy-duty pulley block slides into the heavy-duty track, and the heavy-duty track is grouted to ensure that the middle plate and each "U"-shaped air duct segment are fixed to the middle plate.

[0006] In a further improvement, the vertical right main board extends downward to form a lower mounting plate.

[0007] Further improvements include a left side panel of the air duct comprising a vertical left main board, with a lower horizontal left edge integrally formed on the inner bottom side of the vertical left main board; a right side panel of the air duct comprising a vertical right main board, with a lower horizontal right edge integrally formed on the inner bottom side of the vertical right main board; bolt mounting holes are pre-drilled on both the lower horizontal left edge and the lower horizontal right edge; the air duct base plate is located on the upper surface of the lower horizontal left edge and the lower horizontal right edge; the air duct base plate is detachably and fixedly connected to the left side panel and the right side panel of the air duct by high-strength bolts passing through the bolt mounting holes.

[0008] In a further improvement, the top outer side of the vertical left main board has an integrally formed horizontal flange left edge; the top outer side of the vertical right main board has an integrally formed horizontal flange right edge; threaded through holes are formed on both the left and right flange edges, and the upper end of the second screw passes through the threaded through holes to fix the heavy-duty pulley assembly to the vertical left and vertical right main boards respectively, and the lower end of the second screw is connected to an anti-loosening nut.

[0009] In a further improvement, the heavy-duty pulley block includes a rigid support member that is threadedly fixed to the second screw. The rigid support member has mounting shafts fixed at both ends, and sliding bearings are installed at both ends of the mounting shafts.

[0010] As a further improvement, the strength grade of the UHPC precast panel is UHPC.

[0011] As a further improvement, the heavy-duty track has an inverted U-shaped bottom groove structure.

[0012] The advantages of this utility model are as follows: 1. Significantly Improved Structural Durability: Using UHPC as the material for the prefabricated air duct structure enhances the strength, durability, impermeability, and corrosion resistance of the rail-top air duct, significantly extending its service life. Combined with high-performance sealing of on-site assembly joints and track grouting technology, the overall structural stability and durability are further strengthened. 2. Low structural weight and high strength: The precast rail-top ventilation duct made of UHPC weighs only half that of ordinary concrete, reducing manufacturing, transportation, and installation costs. At the same time, due to the high strength of the UHPC precast rail-top ventilation duct, it can effectively prevent component damage during transportation and installation, reducing the structural breakage rate and ensuring construction quality. 3. Strong spatial adaptability: By using pre-embedded sliding rails and pulley blocks to hoist the air duct structure on the rail top, the problem of limited working space inside the station is effectively solved, demonstrating strong applicability. The hoisting method proposed in this utility model can improve the efficiency and flexibility of air duct installation, reduce construction costs, and reduce the safety risks brought by large machinery.

[0013] 4. Highly efficient construction process: The main structural components are all prefabricated, allowing for on-site assembly, which accelerates construction and reduces on-site construction waste. Furthermore, the pre-embedded sliding rails do not need to be installed simultaneously with the prefabricated ventilation duct main structure, effectively simplifying on-site procedures, improving operational efficiency, and speeding up construction progress. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the prefabricated UHPC rail-top ventilation duct structure for subway stations according to this utility model; Figure 2 This is a schematic cross-sectional view of the prefabricated UHPC rail-top ventilation duct structure for subway stations according to this utility model. Figure 3 This utility model Figure 1 Enlarged view of section A in the middle; Figure 4 This utility model Figure 1 Enlarged view of section B; Figure 5 This utility model Figure 2 Enlarged view of section C; In the picture: 1 is the bottom plate of the air duct, 2 is the left side plate of the air duct, 21 is the vertical left main plate, 22 is the left edge of the flange, 23 is the lower horizontal left edge, 3 is the right side plate of the air duct, 31 is the vertical right main plate, 32 is the right edge of the flange, 33 is the lower horizontal right edge, 34 is the lower hanging plate, 4 is the high-strength bolt, 5 is the second screw, 51 is the first screw, 6 is the heavy-duty pulley block, 61 is the rigid support component, 62 is the mounting shaft, 63 is the sliding bearing, 7 is the heavy-duty rail, and 8 is the through hole slot. Detailed Implementation

[0015] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this patent.

[0016] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] Please see Figure 1-5. A prefabricated UHPC rail-top air duct structure with suspended rails, comprising an air duct structure and a suspended rail structure; the air duct structure is assembled from a left side plate 2, a right side plate 3, and a bottom plate 1. Flange edges are provided on the top of the left side plate 2 and the right side plate 3, with threaded through holes pre-drilled during factory prefabrication for reliable connection with the pulley trolleys of the suspended rail system. The suspended rail structure mainly includes pulley blocks, rails, and connecting parts. Each pulley block consists of four sliding bearings, connected as a whole by rigid support members, forming a four-wheeled trolley structure. A threaded rod runs through the center of the trolley and is securely connected to the threaded through holes at the flanges of the air duct side plates. The rails adopt an inverted U-shaped slotted structure, pre-embedded inside the middle plate of the air duct, serving as the running track for the pulley blocks and effectively bearing the vertical load and horizontal force of the air duct. Bolt holes are pre-drilled on both sides of the bottom plate 1, connecting the bottom plate 1 to the left side plate 2 and the right side plate 3 with high-strength bolts 4.

[0018] The duct side panels are precast in the factory using ultra-high performance concrete (UHPC). The left side panel 2 measures 1150 mm (length) × 1490 mm (width) × 70 mm (height), while the right side panel 3, extending downwards to form a lower hanging panel, measures 1700 mm (length) × 1490 mm (width) × 70 mm (height). Both panels are of UHPC120 strength. UHPC offers advantages such as low weight and ultra-high mechanical properties and durability. Calculations show that the self-weight of a single side panel cast using UHPC is about half that of traditional concrete. Bolt installation holes are pre-drilled at the lower edges of the left side panel 2 and the right side panel 3 of the air duct during the prefabrication process. Through-hole slots 8 are pre-drilled near the lower ends of the left side panel 2 and the right side panel 3 of the air duct so that the first screw 51 can pass through the slot to connect adjacent air duct segments. Three bolt holes are pre-drilled at the top flange edges of the left side panel 2 and the right side panel 3 of the air duct, and three heavy-duty pulley blocks 6 are set at equal intervals.

[0019] The duct base plate 1 is also precast in the factory using ultra-high performance concrete (UHPC), with dimensions of 3130 mm (length) × 1490 mm (width) × 70 mm (height) and a strength grade of UHPC120. Calculations show that the self-weight of a single base plate cast using UHPC is approximately half that of conventional concrete. Bolt mounting holes were pre-drilled at the two long edges of the base plate during prefabrication. High-strength bolts are used on-site to achieve a tight connection with the lower part of the duct side plate, ensuring a tight joint and coordinated load-bearing capacity.

[0020] High-strength bolt 4 is an M20 bolt, grade 8.8, with a diameter of 20 mm and dimensions of 20 mm (length) × 20 mm (width) × 130 mm (height). Two bolt holes are provided at both ends of the bottom plate of each duct section for high-strength bolt connection between the bottom plate and the side plate. However, this invention is not limited to this diameter and grade; adjustments can be made according to operational requirements, and the implementation steps remain the same as in this example.

[0021] The upper end of the second screw 5 is connected to the heavy-duty pulley block 6, and the lower end passes through the reserved holes on the left side plate 2 and the right side plate 3 of the air duct and is then tightened with an anti-loosening nut; the first screw 51 is used to pass through the slot 8 to connect adjacent air duct segments.

[0022] The heavy-duty pulley block 6 consists of four sliding bearings, which are connected as a whole by rigid support members to form a four-wheeled trolley structure.

[0023] The heavy-duty track 7 has an inverted U-shaped slotted structure with the slot opening facing downwards, facilitating smooth sliding and guidance of the heavy-duty pulley block 6 within the slot. The slot width is designed to allow for appropriate running clearance based on the pulley dimensions. The track is an inverted U-shaped slotted track manufactured using hot rolling or cold bending processes. The track undergoes straightening, rust removal, and anti-rust primer treatment at the factory. The track is reliably connected to the ductwork structural layer via anchoring steel bars. After the track is embedded in the ductwork, temporary sealing measures can be taken within the track slot to prevent contamination of the space inside the slot.

[0024] The heavy-duty track is made of low-alloy high-strength structural steel Q355B, but this invention is not limited to this material; carbon structural steel Q235B, etc., can also be used, and the implementation steps are the same as in this example. In addition, the track requires anti-corrosion treatment, using a heavy-duty anti-corrosion coating system for protection.

[0025] The slot 8 is a through-hole slot pre-reserved on the left side plate 2 and the right side plate 3 of the air duct, which facilitates the connection of adjacent air duct segments by the first screw 51 through the through-hole.

[0026] Specifically, the construction method of the precast UHPC rail-top ventilation duct structure provided by this utility model includes the following steps: Step 1: Hoist the first section of the duct side panel. Insert the first screw 51 from top to bottom through the pre-embedded flange holes at the top of the left side panel 2 and the right side panel 3 of the first duct, as well as the mounting holes of the matching heavy-duty pulley block 6. Initially install the gaskets and anti-loosening nuts to form a sliding lifting point. Then, using lifting equipment, hoist the left side panel 2 and the right side panel 3 of the duct, which are connected to the heavy-duty pulley block 6, to the heavy-duty rail 7. Accurately embed the heavy-duty pulley block 6 into the groove of the pre-embedded heavy-duty rail 7, allowing the heavy-duty pulley block 6 to move smoothly and steadily along the heavy-duty rail 7.

[0027] Step 2, Install the duct base plate 1. Hoist the first prefabricated duct base plate 1 to the designated position, precisely adjust it to align the bolt holes, and sequentially insert the high-strength bolts 4 specified in the design from one side to the other to connect the duct base plate 1 to the left side plate 2 and the right side plate 3 of the duct. When installing the bolts, flat washers and spring washers should be added under the bolt heads and lock nuts. After tightening, the first complete "U"-shaped duct segment is formed.

[0028] Step 3: Move the assembled first section of the air duct along the heavy-load track 7 to the designated position, clearing the assembly work surface. Assemble the second and third sections using the same procedure. For each air duct section, use the first screw 51 through the pre-reserved through-hole slot 8 on the lower part of the side plate to assemble adjacent rail-top air duct sections together, and tighten them with anti-loosening nuts and washers. Assemble and tighten subsequent sections using the same procedure, moving and splicing them section by section until a complete air duct is formed.

[0029] Step 4: After all the duct sections are installed and adjusted to meet the requirements, use compressed air to clean the assembly gaps between the heavy-duty pulley block 6 and the heavy-duty track 7, as well as the joints between the duct panels, to remove dust, debris, and other contaminants. Fill the gaps with backing foam rods, and then use high-performance silicone sealant or modified silane polyether sealant to continuously and evenly seal the longitudinal and transverse joints between the duct panels, ensuring that the joints are full and the surface is smooth.

[0030] Step 5: Based on the actual situation, select CABR-MGⅢ-80 cement-based grouting material from the nearest area, mix it with water according to the specified ratio, and utilize its high fluidity and low shrinkage to perform low-pressure grouting from one end of the track groove. Stop grouting after homogeneous grout flows out of the overflow hole at the other end. After grouting is completed, keep the grouting material moist and cured as required to allow it to reach the design strength and finally compact to form an integral load-bearing system.

[0031] The above description only discloses specific embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or modifications that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A prefabricated UHPC rail-top ventilation duct structure with suspended rails, characterized in that, Includes a middle plate, on both sides of the bottom surface of the middle plate, heavy-duty rails (7) are pre-embedded; the heavy-duty rails (7) are fixed with several "U"-shaped air duct segments along the longitudinal direction by pulley blocks (6), and adjacent "U"-shaped air duct segments are fixedly connected to each other; The "U"-shaped air duct segment includes an air duct side plate, which includes a left air duct plate (2) and a right air duct plate (3). The top of the left air duct plate (2) and the right air duct plate (3) is equipped with a heavy-duty pulley block (6) that cooperates with the heavy-duty rail (7). The bottom ends of the left air duct plate (2) and the bottom ends of the right air duct plate (3) are pre-cut with slots (8). The slots (8) have threaded through holes in the longitudinal direction. The first screw (51) passes through the threaded through holes to fix the adjacent "U"-shaped air duct segments. The bottom of the left air duct plate (2) and the right air duct plate (3) is detachably connected to an air duct bottom plate (1). The air duct bottom plate (1) and the left air duct plate (2) and the right air duct plate (3) are all UHPC precast panels. The heavy-duty pulley block (6) slides into the heavy-duty track (7), and the heavy-duty track (7) is grouted to make the middle plate and each "U"-shaped air duct segment fixed to the middle plate.

2. The prefabricated UHPC rail-top ventilation duct structure according to claim 1, characterized in that, The left side plate (2) of the air duct includes a vertical left main plate (21), and the bottom inner side of the vertical left main plate (21) is integrally formed with a lower horizontal left edge (23); the right side plate (3) of the air duct includes a vertical right main plate (31), and the bottom inner side of the vertical right main plate (31) is integrally formed with a lower horizontal right edge (33); bolt mounting holes are reserved on both the lower horizontal left edge (23) and the lower horizontal right edge (33); the bottom plate (1) of the air duct is located on the upper surface of the lower horizontal left edge (23) and the lower horizontal right edge (33); the bottom plate (1) of the air duct is detachably and fixedly connected to the left side plate (2) and the right side plate (3) of the air duct by high-strength bolts (4) passing through the bolt mounting holes.

3. The prefabricated UHPC rail-top ventilation duct structure according to claim 2, characterized in that, The vertical right main board (31) extends downward to form a lower hanging plate (34).

4. The prefabricated UHPC rail-top ventilation duct structure according to claim 2, characterized in that, The top outer side of the vertical left main board (21) has an integrally formed horizontal flange left edge (22); the top outer side of the vertical right main board (31) has an integrally formed horizontal flange right edge (32); threaded through holes are formed on the left edge (22) and the right edge (32) of the flange. The upper end of the second screw (5) passes through the threaded through hole to fix the heavy-duty pulley group (6) to the vertical left main board (21) and the vertical right main board (31) respectively. The lower end of the second screw (5) is connected to an anti-loosening nut.

5. The prefabricated UHPC rail-top ventilation duct structure according to claim 1, characterized in that, The heavy-duty pulley block (6) includes a rigid support member (61) that is threadedly fixed to the second screw (5). The rigid support member (61) has mounting shafts (62) fixed at both ends, and sliding bearings (63) are installed at both ends of the mounting shafts (62).

6. The prefabricated UHPC rail-top ventilation duct structure according to claim 1, characterized in that, The strength grade of the UHPC precast panel is UHPC120.

7. The prefabricated UHPC rail-top ventilation duct structure according to claim 1, characterized in that, The heavy-duty track (7) has an inverted U-shaped bottom slotted structure.

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