Rail transit underground station hot exhaust passage construction method

Abstract

The application discloses a construction method of a heat exhaust channel of a rail transit underground station, and comprises the following steps: lifting an assembled air duct plate by installing a synchronous lifting counter-hoisting device on a top floor slab; supporting the assembled air duct plate by arranging a trolley formwork system on a bottom floor slab; forming a section of the heat exhaust channel by constructing a side wall through a scaffold system; before the side wall reaches a hardness condition, suspending the section of the heat exhaust channel by installing an anchor device to lock a steel strand, transferring the synchronous lifting counter-hoisting device after cutting the steel strand to a next section of the heat exhaust channel, lifting the assembled air duct plate, moving the trolley formwork system to support the next section of the assembled air duct plate, and constructing the next section of the heat exhaust channel by executing the side wall construction; and repeatedly executing the construction of the next section of the heat exhaust channel until the overall construction of the heat exhaust channel is completed. The synchronous lifting counter-hoisting device and the trolley formwork system are transferred and used early, so that the efficiency and progress of each section of the heat exhaust channel are improved.

Description

Technical Field

[0001] This invention relates to the field of rail transit engineering technology, and in particular to a construction method for a thermal exhaust duct in a rail transit station. Background Technology

[0002] Underground rail transit stations include a ground floor slab and a top floor slab. A heat exhaust duct needs to be installed on the top floor slab directly above the subway train to quickly remove the heat emitted by the train when it stops at the platform, preventing the temperature of the subway train track area from being too high and affecting the operation of equipment inside the subway train and passenger comfort; and to assist in the removal of smoke in the event of a fire. The hot exhaust duct can be constructed using a combination of prefabricated and cast-in-place processes. Prefabricated duct panels are installed segment by segment on the top floor slab of the underground rail transit station using a prefabricated process. Then, side walls are constructed on both sides of the prefabricated duct panels, parallel to the width of the top floor slab, using a cast-in-place process to form a hollow hot exhaust duct structure. However, due to the narrowness of the subway train track area, it is difficult to introduce hoisting equipment such as truck cranes to lift the prefabricated duct panels to the target height. During the curing stage after the side wall construction, since the side wall is a suspended wall, the formwork can only be removed after the concrete strength of the side wall reaches 100%, which seriously affects the construction efficiency of the next section of the hot exhaust duct and delays the overall construction cycle of the hot exhaust duct. Summary of the Invention

[0003] The purpose of this invention is to provide a construction method for thermal exhaust ducts in rail transit stations. This method addresses the problems encountered when using prefabricated construction techniques to construct thermal exhaust ducts in underground rail transit stations. These problems include the difficulty in installing prefabricated duct panels due to the narrow track area, which prevents the introduction of hoisting equipment, and the long curing period of cast-in-place sidewalls, which requires waiting for the completion of one section of sidewall before proceeding with the next section of prefabricated duct panel and its sidewall construction. This results in low construction efficiency and a long construction period for each section of the exhaust duct, delaying the overall progress of the thermal exhaust duct project.

[0004] To solve the above-mentioned technical problems, the present invention provides a construction method for a thermal exhaust duct in an underground rail transit station, comprising:

[0005] Prefabricated ventilation duct panel inverted lifting: A synchronous lifting inverted lifting device consisting of a gantry frame, a through-hole jack, steel strands, and a hydraulic control system is installed at the location of the hot exhaust duct to be constructed on the top floor slab of the underground rail transit station. The steel strands are vertically passed through the top floor slab and connected to a section of prefabricated ventilation duct panel located on the bottom floor slab of the underground rail transit station. The hydraulic control system controls the through-hole jack to synchronously raise and lower the steel strands, lifting the connected prefabricated ventilation duct panel to the target height position below the top floor slab.

[0006] Prefabricated air duct support: On the ground floor of the underground station of the rail transit, a trolley formwork system consisting of double-track rails, a movable frame, a trolley formwork, and multiple screw lifts evenly distributed at at least one of its upper and lower ends is arranged in the length direction of the hot exhaust duct to be constructed. The trolley formwork system is supported on the prefabricated air duct that is lifted in reverse by synchronously controlling the lifting height of the screw lifts.

[0007] Side wall construction: A set of temporary scaffolding is installed on each side of the underground rail transit station in the width direction of the trolley formwork system to form a scaffolding system. The scaffolding system is used to connect the side wall reinforcement and erect the side wall formwork on both sides of the width direction of the prefabricated air duct slab at the target height position. Concrete is poured in the side wall formwork to form a concrete side wall. The prefabricated air duct slab is connected to the top floor slab of the underground rail transit station through the side wall to form a hot exhaust channel.

[0008] Construction of the next section of the hot exhaust duct: Before the previous section of the sidewall reaches the required hardness, anchors are installed on each steel strand and abutted against the top floor slab. The steel strands above each anchor are cut off. The anchors are used to fix the steel strands and suspend the previous section of the hot exhaust duct. The synchronous lifting and reverse hoisting device after cutting the steel strands is transferred and installed on the top floor slab at the location of the next section of the hot exhaust duct to be constructed. The steel strands are vertically passed through the top floor slab and connected to the next section of the prefabricated air duct plate located on the bottom floor slab of the underground rail transit station. The next section of the prefabricated air duct plate is controlled to be reverse hoisted to the target height position below the top floor slab. The trolley formwork system is moved out from the double-row track below the previous section of the prefabricated air duct plate and moved in to support the next section of the prefabricated air duct plate. The construction of this section of the sidewall is then carried out to complete the construction of the next section of the hot exhaust duct.

[0009] The hot exhaust duct is formed as a whole: the construction of the next section of the hot exhaust duct is repeated until the construction of all sections of the hot exhaust duct is completed to form the complete structure of the hot exhaust duct.

[0010] Furthermore, in the construction method for the thermal exhaust duct of an underground rail transit station provided by the present invention, during the side wall construction step, the scaffolding system further includes multiple horizontal bars that connect the two sets of temporary scaffolding on both sides into a whole through the trolley formwork.

[0011] Furthermore, the construction method for the thermal exhaust channel of an underground rail transit station provided by the present invention involves connecting the crossbar to the trolley formwork.

[0012] Furthermore, in the construction method for the thermal exhaust duct of an underground rail transit station provided by the present invention, during the side wall construction step, the scaffolding system further includes a figure-eight brace installed at an angle between each set of temporary scaffolding and the ground floor slab of the underground rail transit station, wherein the figure-eight brace is located on the outside of the temporary scaffolding.

[0013] Furthermore, in the construction method for the thermal exhaust duct of an underground rail transit station provided by the present invention, the trolley formwork in the prefabricated duct support includes a frame composed of uprights, transverse bars, longitudinal bars and diagonal bars, and also includes four directional guide wheels arranged in a rectangular pattern on two transverse bars located in the width direction of the thermal exhaust duct to be constructed at the lowest layer of the frame. The lower surface elevation of the directional guide wheels is lower than the elevation of the lower end of the uprights.

[0014] Furthermore, the construction method for the thermal exhaust duct of an underground rail transit station provided by the present invention includes a mobile frame comprising a crossbeam and two vertically downward-arranged sliding feet, the two rows of sliding feet being slidably installed on two rows of tracks in a one-to-one correspondence, and the crossbeam being supported on two directional guide wheels on a horizontal bar at the bottom of the frame.

[0015] Furthermore, the construction method for the thermal exhaust duct of an underground rail transit station provided by the present invention includes a mobile frame comprising a crossbeam and a double row of directional pulleys arranged vertically downwards. The directional pulleys are slidably installed on the double-row rails in a one-to-one correspondence. The crossbeam is supported on four directional pulleys arranged in a rectangular pattern on the frame.

[0016] Furthermore, the construction method for the thermal exhaust duct of an underground rail transit station provided by the present invention further includes, in the step of forming the overall thermal exhaust duct, the following: connecting the two adjacent prefabricated duct panels by pouring concrete through a suspended formwork between the assembly joints of the two adjacent prefabricated duct panels.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] The present invention provides a construction method for hot exhaust ducts in rail transit stations. By installing a synchronous lifting and counter-lifting device at any section of the hot exhaust duct to be constructed on the top floor slab of an underground rail transit station, the prefabricated duct panels below are lifted using the reaction force of the synchronous lifting and counter-lifting device to a target height below the top floor slab. This method achieves lifting and lowering control of the prefabricated duct panels without occupying internal space in the rail transit station, thus enabling the smooth implementation of prefabricated construction processes using prefabricated duct panels, improving construction efficiency, and shortening the duct length. The construction cycle of the slabs avoids the need for full-span scaffolding and cast-in-place construction of the duct slabs. The trolley formwork system provides weight load support for each section of the prefabricated duct slab as it is lifted to the target height. This dual approach of lifting and support ensures the stability of each section at the target height, preventing structural instability caused by suspension and ensuring the stability of the duct slabs at the target height for sidewall construction. Anchors are installed on each steel strand to abut against the top floor slab, utilizing the anchors and their connected steel strands... The weight load of each section of the hot exhaust duct is suspended by a wire rope. Then, the steel strands are cut, and the synchronous lifting and reverse hoisting device, after the steel strands are cut, is transferred and installed as a whole on the top floor slab of the next section of the hot exhaust duct to be constructed. This allows for the connection and reaction lifting of the next section of the prefabricated duct panel, avoiding the occupation of the synchronous lifting and reverse hoisting device during the side wall curing period. This early transfer and use of the synchronous lifting and reverse hoisting device improves the efficiency and progress of the hoisting construction of the next section of the hot exhaust duct. Simultaneously, it allows the trolley formwork system to be moved from the double-track system below the previous section of the prefabricated duct panel. The trolley formwork system is moved out and then moved in to support the next prefabricated air duct panel, allowing the trolley formwork system to be transferred and supported in advance to the next prefabricated air duct panel after the reaction force hoisting. This enables the early transfer and use of the trolley formwork system, thereby improving the support efficiency and progress of the next prefabricated air duct panel. It avoids the situation where the concrete curing strength of each section of the side wall can only be reached 100% before the previous trolley formwork system can be moved out, thus improving the construction progress of each section of the hot exhaust channel, thereby improving the overall construction progress of the hot exhaust channel and greatly shortening the overall construction cycle of the hot exhaust channel.

[0019] The construction method for the thermal exhaust duct of rail transit stations provided by the present invention enables synchronous lifting and fine adjustment of the top elevation of the trolley formwork system by using a spiral lifter arranged at the same end of the trolley formwork system, thereby achieving the height adjustment accuracy of the trolley formwork system.

[0020] The construction method for the thermal exhaust duct of rail transit stations provided by this invention utilizes anchors to fix steel strands to suspend and connect each section of the thermal exhaust duct. Once the concrete curing strength of the side walls of each section of the thermal exhaust duct reaches 100%, the side wall formwork and steel strands can be removed without affecting the construction of the next section of the thermal exhaust duct. Attached Figure Description

[0021] Figure 1 This is a flowchart of the construction method for the thermal exhaust duct of a rail transit station;

[0022] Figure 2 This is a schematic diagram of the elevation structure of the gantry frame, through-hole jacks, and hydraulic control system for arranging a synchronous lifting and reverse hoisting device on the top floor slab of a rail transit station.

[0023] Figure 3 This is a schematic diagram of the elevation structure of a prefabricated air duct panel connected to the bottom floor slab through a synchronous lifting and reverse hoisting device located on the top floor slab of a rail transit station.

[0024] Figure 4 This is a schematic diagram of the facade structure, which shows how the prefabricated air duct panel is lifted to a position exceeding the target height using a synchronous lifting and reversing device.

[0025] Figure 5 This is a schematic diagram of the elevation structure in which a trolley frame system is arranged under the prefabricated air duct plate after it has been lifted and the prefabricated air duct plate is placed and supported on the trolley frame system.

[0026] Figure 6 This is a schematic diagram of the elevation structure of temporary scaffolding installed on both sides of the width direction of the trolley formwork system;

[0027] Figure 7 This is a schematic diagram of the elevation structure of the vehicle formwork system that removes the prefabricated air duct plate from the previous hot exhaust channel.

[0028] Figure 8 This is a schematic diagram of the facade structure from another perspective, showing the continuous construction of multiple sections of hot exhaust ducts.

[0029] Figure 9 This is an enlarged view of the construction of the horizontal joint at the junction of adjacent prefabricated air duct panels;

[0030] Figure 10 This is a three-dimensional structural diagram of the heat exhaust duct of a rail transit station;

[0031] As shown in the figure:

[0032] 100. Underground space structure; 110. Ground floor slab; 111. Floor slab opening; 120. Top floor slab; 121. Guide wall; 122. Guide wall reinforcement; 130. Wall; 140. Plain concrete layer; 150. Track; 160. Subway train.

[0033] 200. Synchronous lifting and reverse hoisting device; 210. Gantry frame; 220. Through-hole jack; 230. Steel strand; 240. Hydraulic control system; 250. Anchorage.

[0034] 300. Hot exhaust duct; 310. Prefabricated air duct panel; 311. Lifting ring; 320. Side wall; 321. Side wall reinforcement.

[0035] 400. Trolley frame system; 410. Track; 420. Mobile frame; 430. Trolley frame; 431. Upright pole; 432. Horizontal pole; 433. Diagonal pole; 434. Ladder; 435. Guide wheel; 436. Operating platform; 440. Screw jack.

[0036] 500. Scaffolding system; 510. Temporary scaffolding; 520. Horizontal bar; 530. A-frame brace.

[0037] 600. Hanging mold. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0039] Please refer to Figure 2 and Figure 10 The underground space structure of the floor where the heat exhaust duct of the underground rail transit station is located includes the ground floor slab 110, the top floor slab 120, the wall 130, and the plain concrete layer 140. The floor where the heat exhaust duct is located includes, but is not limited to, the third basement level.

[0040] Please refer to Figure 1 This invention provides a construction method for a thermal exhaust duct in an underground rail transit station, mainly including the steps of inverted lifting of prefabricated duct panels, support of prefabricated duct panels, side wall construction, construction of a section of the thermal exhaust duct, and overall formation of the thermal exhaust duct. Wherein:

[0041] Arrangement of synchronous lifting and reverse hoisting device:

[0042] Please refer to Figures 2 to 3 A synchronous lifting and reversing device 200, consisting of a gantry frame 210, a through-hole jack 220, steel strands 230, and a hydraulic control system 240, is installed at the location of the hot exhaust duct to be constructed on the top floor slab 120 of the underground rail transit station. The steel strands 230 are vertically passed through the top floor slab 120 and connected to a section of prefabricated ventilation duct 310 located on the bottom floor slab 110 of the underground rail transit station. The gantry frame 210 is set on the top floor slab 120, and multiple through-hole jacks 220 are arranged vertically in multiple rows and columns on the gantry frame 210. Each steel strand 230 is threaded through a corresponding through-hole jack 220, and the hydraulic control system 240 is set on the gantry frame 210.

[0043] When the ground floor slab 110 is uneven, a plain concrete layer 140 can be constructed on the ground floor slab 110 to level it. At this time, the ground floor slab 110 includes the plain concrete layer 140.

[0044] In order to run the steel strand 230 through the top floor slab 120, a floor opening 111 that runs vertically through the top floor slab 120 is required.

[0045] To connect the steel strand 230 to the prefabricated air duct panel 310, lifting rings 311 can be embedded at corresponding positions on the prefabricated air duct panel 310. The prefabricated air duct panel 310 can be fabricated on-site on the ground floor slab 110, or it can be prefabricated in a factory and transported to the ground floor slab 110 of the underground rail transit station. The through-hole jacks 220, steel strand 230, and lifting rings 311 are arranged in a one-to-one correspondence, including but not limited to six arranged in double rows.

[0046] The hydraulic control system 240 includes a hydraulic controller and a hydraulic pump station.

[0047] Prefabricated air duct panel reverse lifting:

[0048] Please refer to Figures 3 to 4 The hydraulic control system 240 controls the through-hole jack 220 to synchronously lift and lower the steel strand 230 on it, raising the prefabricated air duct plate 310 connected to it to the target height position below the top floor slab 120.

[0049] Prefabricated air duct panel support:

[0050] Please refer to Figure 5A trolley formwork system 400 is arranged on the ground floor slab 110 of the underground rail transit station along the length of the hot exhaust duct to be constructed. This system consists of a double-track 410, a movable frame 420, a trolley formwork 430, and multiple screw lifts 440 evenly distributed at at least one of its upper and lower ends. The trolley formwork system 400 is supported on the inverted, prefabricated duct slab 310 by synchronously controlling the lifting height of the screw lifts 440. The screw lifts 440 can be electric or manual. The trolley formwork 430 includes a frame composed of uprights 431, transverse bars 432, longitudinal bars, and diagonal bars 433. It also includes four rectangularly distributed guide wheels 435 on the two transverse bars 432 at the bottom layer of the frame, along the width of the hot exhaust duct to be constructed. The lower surface elevation of the guide wheels 435 is lower than the lower end elevation of the uprights 431. The frame may also include a ladder 434 and an operating platform 436 mounted on it, through which the synchronous lifting and lowering of the screw jack 440 can be controlled. The double-track 410 can be the rail 150 of the subway train 160, so as to realize the reuse of the rail 150 and reduce the cost of re-laying the double-track 410.

[0051] Please refer to Figures 4 to 5 In order to stably place the prefabricated air duct plate 310 after being lifted in reverse onto the trolley frame system 400, the prefabricated air duct plate 310 can be lifted in reverse to a target height position by the synchronous lifting reverse lifting device 200. For example, the prefabricated air duct plate 310 can be lifted in reverse to a height position of about 20cm above the target height position. After the trolley frame system 400 moves into this section of prefabricated air duct plate 310, the prefabricated air duct plate 310 is lifted in reverse and lowered onto the trolley frame system 400 by the synchronous lifting reverse lifting device 200. When the upper end of the trolley frame 430 is equipped with a screw jack 440, the prefabricated air duct plate 310 is lifted in reverse and lowered onto the screw jack 440. When the upper end of the trolley frame 430 is not equipped with a screw jack 440, the prefabricated air duct plate 310 is lifted in reverse and lowered onto the upper surface of the trolley frame 430.

[0052] To facilitate the movement of the trolley formwork 430 along the length of the hot exhaust duct to be constructed, the movable frame 420 includes a crossbeam and two vertically downward-facing rows of sliding feet or two rows of directional pulleys. The two rows of sliding feet or directional pulleys are slidably mounted on the double-row rails 410. The crossbeam is supported by four rectangularly distributed directional guide wheels 435 on the frame of the trolley formwork 430. In this configuration, the movable frame 420 presents a trolley-like structure consisting of one crossbeam and four sliding feet or four directional pulleys. However, it is not limited to this configuration; the movable frame 420 can also be a bench-like structure consisting of a crossbeam and two corresponding sliding feet or two directional pulleys. The movable frame 420 carries the trolley formwork 430 along the length of the double-row rails 410, while the directional guide wheels 435 move relative to the movable frame 420 along the width of the double-row rails 410, thereby precisely adjusting the arrangement position of the trolley formwork system 400.

[0053] Side wall construction:

[0054] Please refer to Figure 6 A set of temporary scaffolding 510 is installed on each side of the underground rail transit station in the width direction of the trolley formwork system 400 to form a scaffolding system 500. The scaffolding system 500 is used to connect the side wall steel bars 321 and erect the side wall formwork on both sides of the width direction of the prefabricated air duct 310 at the target height position. Concrete is poured in the side wall formwork to form a concrete side wall 320. The prefabricated air duct 310 is connected to the top floor slab 120 of the underground rail transit station through the side wall 320 to form a section of hot exhaust channel 300.

[0055] Please refer to Figure 3 and Figure 6 To improve the connection strength and stress reliability at the side wall 320, during the construction of the side wall 320, when constructing the top floor slab 120 of the underground rail transit station, a vertically downward distributed guide wall 121 is reserved at the boundary of the area to be constructed in the hot exhaust channel below the top floor slab 120. Guide wall steel bars 122 are reserved on the guide wall 121. The side wall steel bars 321 and the guide wall steel bars 122 are staggered and welded on one side, with a welding length of not less than 15d, where d is the diameter of the side wall steel bars 321.

[0056] To improve the pouring quality of side wall 320, a hopper was pre-installed during the erection of the side wall formwork. Self-compacting concrete was poured into the side wall formwork through the hopper, and a micro-vibrator was used to micro-vibrate the self-compacting concrete inside the formwork to remove air bubbles, ensuring that the concrete at the vertical joint construction node of side wall 320 was dense and free of voids. During the construction of side wall 320, the vertical joints were dense, smooth in appearance, leak-proof, with reliable reinforcement connections and strong overall structural integrity.

[0057] Please refer to Figure 6To ensure the stability of the scaffolding system 500, the scaffolding system 500 also includes multiple horizontal bars 520 that connect the two sets of temporary scaffolding 510 on both sides into a whole through the trolley formwork 430. Connecting the two sets of temporary scaffolding 510 into a whole through the horizontal bars 520 improves the stability of the scaffolding system 500. To further ensure the stability of the two sets of temporary scaffolding 510 after installation, the horizontal bars 520 can be connected to the trolley formwork 430.

[0058] Please refer to Figure 6 To further improve the stability of the installed scaffolding system, the scaffolding system 500 also includes diagonal bracing 530 installed between each set of temporary scaffolding 510 and the ground floor slab 110 of the underground rail transit station. The diagonal bracing 530 is located on the outside of the temporary scaffolding 510. Multiple diagonal bracing 530s can be arranged at different heights and angles.

[0059] Next section of hot exhaust duct construction:

[0060] Please refer to Figures 6 to 8 Before the previous section of sidewall 320 reaches the required hardness, anchors 250 are installed on each steel strand 230 and abutted against the top floor slab 120. The steel strands 230 above each anchor 250 are then cut. The anchors 250 are used to fix the steel strands 230 and suspend the previous section of the hot exhaust duct 300. The synchronous lifting and reverse hoisting device 200 after cutting the steel strands 230 is then transferred and installed as a whole on the top floor slab 120 at the location of the next section of the hot exhaust duct to be constructed. The steel strands 230 are then vertically passed through the top floor slab. Floor slab 120 is connected to the next section of prefabricated ventilation duct 310 of the bottom floor slab 110 of the underground rail transit station and controls the reverse hoisting of the next section of prefabricated ventilation duct 310 to the target height position below the top floor slab 120; the trolley formwork system 400 is moved out from the double-track rails 410 below the previous section of prefabricated ventilation duct 310 and moved in to support the next section of prefabricated ventilation duct 310, and the construction of the next section of the hot exhaust duct 300 is completed by performing the construction of the side wall 320. The anchor 250 can be pre-installed on the steel strand 230 when installing the synchronous lifting reverse hoisting device, or it can be installed on the steel strand 230 afterward.

[0061] The entire hot air exhaust duct is formed:

[0062] Please refer to Figures 8 to 10The construction of the next section of the hot exhaust duct 300 is repeated until all sections of the hot exhaust duct 300 are completed, forming a complete structure of the hot exhaust duct 300. To form a complete hot exhaust duct 300 structure, this step may also include: connecting the horizontal gaps between adjacent prefabricated duct panels 310 by pouring concrete using a suspended formwork 700 at the assembly joints. After the complete hot exhaust duct 300 is formed, when the subway train 160 runs on the rails 150, the heat emitted by the subway train 160 when it stops at the platform of the underground rail transit station is quickly discharged through the hot exhaust duct 300 directly above the subway train 160, preventing excessively high temperatures in the underground space where the subway train 160 runs, which could affect subway operation and passenger comfort.

[0063] The construction method for thermal exhaust ducts in rail transit stations provided in this invention involves installing a synchronous lifting and counter-lifting device 200 at any section of the thermal exhaust duct to be constructed on the top floor slab 120 of the underground rail transit station. The synchronous lifting and counter-lifting device 200 then uses its reaction force to lift the prefabricated ductwork 310 below the top floor slab 120 to a target height below the top floor slab 120. This achieves lifting and lowering control of the prefabricated ductwork 310 without occupying the internal space of the rail transit station, thus enabling the smooth implementation of the prefabricated process using the prefabricated ductwork 310, improving the construction efficiency of the ductwork slab and shortening the construction time. The construction period avoids the use of full-span scaffolding and cast-in-place construction techniques for the air duct slabs. The trolley formwork system 400 provides weight load support for each section of the prefabricated air duct slab 310, which is lifted to the target height. This dual method of lifting and support ensures the stability of each section of the prefabricated air duct slab 310 at the target height, preventing structural instability caused by suspension. This ensures the stability of each section of the prefabricated air duct slab 310 at the target height for the construction of the side walls 320. Anchors 250 are installed on each steel strand 230 and abut against the top floor slab 120. The anchors 250 and their connected steel strands 230 are used to support the structure. The weight load of each section of the hot exhaust duct is suspended and tied, and then the steel strand 230 is cut. The synchronous lifting and reverse hoisting device 200 after cutting the steel strand 230 is transferred and installed on the top floor slab 120 at the location of the next section of the hot exhaust duct to be constructed. The connection and reaction force hoisting of the next section of the prefabricated air duct 310 are then carried out. This avoids the occupation of the synchronous lifting and reverse hoisting device 200 during the maintenance period of the side wall 320, and realizes the early transfer and use of the synchronous lifting and reverse hoisting device 200. This improves the efficiency and progress of the hoisting construction of the next section of the hot exhaust duct. At the same time, it can move the trolley formwork system 400 from the double track 41 below the previous section of the prefabricated air duct 310. The trolley formwork system 400 is moved out and moved in to support the next prefabricated air duct 310, allowing the trolley formwork system 400 to be transferred and supported in advance to the next prefabricated air duct 310 after the reaction force hoisting. This enables the early transfer and use of the trolley formwork system 400, thereby improving the support efficiency and progress of the next prefabricated air duct 310. It avoids the situation where the concrete curing strength of each section of the side wall 320 must reach 100% before the previous trolley formwork system 400 can be moved out, thus improving the construction progress of each section of the hot exhaust duct 300, thereby improving the overall construction progress of the hot exhaust duct 300 and greatly shortening the overall construction cycle of the hot exhaust duct 300.

[0064] The construction method for the thermal exhaust duct of a rail transit station provided in this embodiment of the invention enables the synchronous lifting and fine adjustment of the top elevation of the trolley formwork system 400 by using a spiral lift 440 arranged at the same end of the trolley formwork system 400, thereby achieving the height adjustment accuracy of the trolley formwork system 400.

[0065] The construction method for the thermal exhaust duct of rail transit stations provided in this embodiment of the invention uses anchors 250 to fix steel strands 230 to suspend and tie each section of the thermal exhaust duct 300. The side wall formwork and steel strands 230 can be removed when the concrete curing strength of the side wall 320 of each section of the thermal exhaust duct 300 reaches 100%, without affecting the construction of the next section of the thermal exhaust duct.

[0066] This invention is not limited to the specific embodiments described above. Obviously, the embodiments described above are only a part of the embodiments of this invention, not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of this invention are within the scope of protection of this invention. Those skilled in the art can make other modifications and variations to this invention. Therefore, if these modifications and variations of this invention fall within the scope of the claims of this invention, then this invention also intends to include these modifications and variations.

Claims

1. A construction method for a thermal exhaust duct in an underground rail transit station, characterized in that, include: Prefabricated ventilation duct panel inverted lifting: A synchronous lifting inverted lifting device consisting of a gantry frame, a through-hole jack, steel strands, and a hydraulic control system is installed at the location of the hot exhaust duct to be constructed on the top floor slab of the underground rail transit station. The steel strands are vertically passed through the top floor slab and connected to a section of prefabricated ventilation duct panel located on the bottom floor slab of the underground rail transit station. The hydraulic control system controls the through-hole jack to synchronously raise and lower the steel strands, lifting the connected prefabricated ventilation duct panel to the target height position below the top floor slab. Prefabricated air duct support: On the ground floor of the underground rail transit station corresponding to the length of the hot exhaust duct to be constructed, a trolley formwork system consisting of double-track rails, a movable frame, a trolley formwork, and multiple screw lifts evenly distributed at at least one of its upper and lower ends is arranged. The trolley formwork system is supported on the prefabricated air duct panel that is lifted in reverse by synchronously controlling the lifting height of the screw lifts. Side wall construction: A set of temporary scaffolding is installed on each side of the underground rail transit station in the width direction of the trolley formwork system to form a scaffolding system. The scaffolding system is used to connect the side wall reinforcement and erect the side wall formwork on both sides of the width direction of the prefabricated air duct slab at the target height position. Concrete is poured in the side wall formwork to form a concrete side wall. The prefabricated air duct slab is connected to the top floor slab of the underground rail transit station through the side wall to form a hot exhaust channel. Construction of the next section of the hot exhaust duct: Before the previous section of the sidewall reaches the required hardness, anchors are installed on each steel strand and abutted against the top floor slab. The steel strands above each anchor are cut off. The anchors are used to fix the steel strands and suspend the previous section of the hot exhaust duct. The synchronous lifting and reverse hoisting device after cutting the steel strands is transferred and installed on the top floor slab at the location of the next section of the hot exhaust duct to be constructed. The steel strands are vertically passed through the top floor slab and connected to the next section of the prefabricated air duct plate located on the bottom floor slab of the underground rail transit station. The next section of the prefabricated air duct plate is controlled to be reverse hoisted to the target height position below the top floor slab. The trolley formwork system is moved out from the double-row track below the previous section of the prefabricated air duct plate and moved in to support the next section of the prefabricated air duct plate. The construction of this section of the sidewall is then carried out to complete the construction of the next section of the hot exhaust duct. The entire hot exhaust duct is formed by repeating the construction of the next section of the hot exhaust duct until all sections of the hot exhaust duct are completed and the complete structure of the hot exhaust duct is formed.

2. The construction method for the thermal exhaust duct of an underground rail transit station according to claim 1, characterized in that, During the side wall construction process, the scaffolding system also includes multiple horizontal bars that connect the two sets of temporary scaffolding on both sides into a whole through the trolley formwork.

3. The construction method for the thermal exhaust duct of an underground rail transit station according to claim 2, characterized in that, The crossbar is connected to the trolley mold frame.

4. The construction method for the thermal exhaust duct of an underground rail transit station according to claim 2, characterized in that, During the side wall construction, the scaffolding system also includes diagonal bracing installed between each set of temporary scaffolding and the ground floor slab of the underground rail transit station, with the diagonal bracing located on the outside of the temporary scaffolding.

5. The construction method for the thermal exhaust duct of an underground rail transit station according to claim 1, characterized in that, In the prefabricated air duct support, the trolley frame includes a frame composed of uprights, transverse bars, longitudinal bars and diagonal bars, and also includes four directional guide wheels arranged in a rectangular pattern on two transverse bars located in the width direction of the hot exhaust duct to be constructed at the bottom layer of the frame. The lower surface elevation of the directional guide wheels is lower than the elevation of the lower end of the uprights.

6. The construction method for the thermal exhaust duct of an underground rail transit station according to claim 5, characterized in that, The mobile frame includes a crossbeam and two rows of vertically downward sliding feet. The two rows of sliding feet are slidably installed on the two rows of tracks, and the crossbeam is supported on two directional guide wheels on a horizontal bar at the bottom of the frame.

7. The construction method for the thermal exhaust duct of an underground rail transit station according to claim 6, characterized in that, The mobile frame includes a crossbeam and two rows of vertically downward-facing directional pulleys. The two rows of directional pulleys are slidably mounted on the two rows of tracks, and the crossbeam is supported on four directional pulleys that are rectangularly distributed on the frame.

8. The construction method for the thermal exhaust duct of an underground rail transit station according to claim 1, characterized in that, The overall formation process of the hot exhaust duct also includes: connecting the two adjacent prefabricated duct panels by pouring concrete through a suspended formwork between the assembly joints of the two adjacent prefabricated duct panels.

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