Subway wall-mounted air duct construction method

Abstract

The application discloses a subway wall-hung air duct construction method, which comprises the following steps: subway station main body construction; L-shaped retaining wall construction; vertical support system construction; wall-hung air duct structure construction; wherein the wall-hung air duct has multiple layers, and the wall-hung air duct structure construction comprises the following steps: upper layer wall-hung air duct construction; vertical support system breaking in the layer wall-hung air duct; lower layer wall-hung air duct construction; repeating the above steps; or, the wall-hung air duct structure construction comprises the following steps: wall-hung air duct layer-by-layer reverse construction; vertical support system breaking. The subway wall-hung air duct construction method adopts L-shaped retaining wall + cantilever half pile + cover-dig support crown beam + lattice column to form a temporary support system, and under the premise of structure top plate without soil covering or low load, the lattice column which is cheap and simple in process is used to replace the cover-dig steel pipe column which is high in cost, and finally the lattice column is replaced by the post-cast concrete middle column, so that the engineering cost is reduced to the maximum.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of subway construction, and particularly relates to a subway wall-hung air duct construction method. BACKGROUND

[0002] In the prior art, open excavation construction is mainly used in the construction of a subway station and its auxiliary structure, and the main structure of the station is constructed first, and then the auxiliary structure is constructed.

[0003] The wall-hung air duct of the open excavation subway shares a support structure with the station structure, and the wall-hung air duct structure is constructed layer by layer from bottom to top, and concrete plates such as bottom plates, middle plates and top plates are arranged intermittently at the contact part with the station support pile. After the early-stage structure construction is completed, the vertical formwork support system of the structure plates of each layer is reserved, and then the support structure of the early-stage post-pouring belt part on the top plate, the middle plate and the bottom plate is removed from top to bottom, and then the late-stage post-pouring belt structure of the bottom plate, the side wall, the middle plate and the top plate is constructed from bottom to top in sequence. The construction method and sequence of the late-stage post-pouring belt structure are the same as those of the early-stage post-pouring belt.

[0004] The defects of the existing construction method are as follows:

[0005] 1. When the support structure on the early-stage post-pouring belt is removed, the removal operation space is narrow, and mechanical operation cannot be used, only manual removal can be used, which not only has low efficiency, but also has high safety risk;

[0006] 2. The wall-hung air duct has multiple layers, and the support structure is removed layer by layer, and each layer is divided into two times of removal, so that the construction times are increased, the construction period is increased, and the construction cost is increased;

[0007] 3. During the construction, removal and re-construction of the post-pouring belt, waterproofing and waterproofing operation need to be performed at the construction joints, and due to the above two defects, the construction joints have the problems of large number and unevenness, and the construction joints in the form of Ma Yacha greatly increase the difficulty of waterproofing operation;

[0008] 4. The construction, removal and re-construction of the post-pouring belt result in that the steel joints at the construction position are dense, and most of the joints are short steel bars, so that the structure strength and integrity are poor, and the structural reliability of the wall-hung air duct is reduced;

[0009] 5. The construction process and the stress system of the structure are frequently converted, which affects the structural reliability of the wall-hung air duct, and the construction period of the post-pouring belt is long, which further increases the construction period. SUMMARY

[0010] The present application aims to provide a subway wall-hung air duct construction method to solve the above problems in the prior art.

[0011] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0012] A subway wall-hung air duct construction method, comprising the following steps:

[0013] Subway station main body construction;

[0014] L-shaped retaining wall construction;

[0015] Vertical support system construction;

[0016] Wall-hung air duct structure construction;

[0017] The wall-hung air duct has multiple layers, and the wall-hung air duct structure construction comprises the following steps: construction of the previous layer of wall-hung air duct; removal of the vertical support system in the current layer of wall-hung air duct; construction of the next layer of wall-hung air duct; and repeating the above steps.

[0018] Alternatively, the wall-hung air duct structure construction comprises the following steps: layer-by-layer top-down construction of the wall-hung air duct; and removal of the vertical support system.

[0019] In a possible design, the L-shaped retaining wall construction comprises the following steps:

[0020] The L-shaped retaining wall is constructed on the station roof, and the L-shaped retaining wall is close to the inner side of the station crown beam;

[0021] After the L-shaped retaining wall reaches the design strength, the earthwork is backfilled in layers;

[0022] The earthwork is rolled and compacted;

[0023] Correspondingly, the station main body comprises the station roof and the station crown beam.

[0024] In a possible design, the vertical support system construction comprises the following steps:

[0025] Construction of latticed columns and station enclosure structure;

[0026] Crown beam shallow pit excavation;

[0027] Construction of cantilever half piles, cantilever half pile top crown beams, and cover-excavation support crown beams.

[0028] In a possible design, the station enclosure structure comprises station enclosure piles and air duct enclosure piles, the station enclosure piles are connected to the station main body, and the air duct enclosure piles are arranged opposite the station enclosure piles; the air duct enclosure piles are arranged below the crown beam shallow pit, and the cantilever half piles and the cover-excavation support crown beams are arranged on the top surface of the air duct enclosure piles.

[0029] In a possible design, a sand-filled layer is arranged above the latticed columns, and a vertical column pile is arranged below the latticed columns and below the wall-hung air duct.

[0030] In a possible design, the wall-mounted air duct construction comprises the following steps: excavating earthwork to form a foundation pit and chiseling the station enclosure; leveling the foundation pit; constructing a concrete cushion on the pit bottom; constructing a waterproof layer on the pit side wall; erecting a formwork support system and constructing the wall-mounted air duct; and removing the formwork support system.

[0031] In a possible design, the earthwork is excavated to 2-2.4 meters below the top plate; the concrete cushion has a thickness of 10-18 centimeters and is made of concrete with a mark of C15, C20, C25 or C30.

[0032] In a possible design, the wall-mounted air duct structure construction further comprises the following steps: covering and backfilling; and rolling construction.

[0033] Beneficial effects:

[0034] The subway wall-mounted air duct construction method adopts an L-shaped retaining wall + cantilever half-pile + cover-excavation support crown beam + lattice column to form a temporary support system, and the lattice column is underpinned when the post-poured concrete wall and column reach the design strength. The method absorbs the construction idea of the cover-excavation top-down method, and replaces the high-cost cover-excavation steel pipe column with a cheap and simple lattice column under the premise of no soil covering or low load on the structure top plate. Finally, the lattice column is underpinned by the post-poured concrete middle column, which maximally reduces the engineering cost.

[0035] The multi-layer wall-mounted air duct is constructed from top to bottom, and the enclosure between the wall-mounted air duct and the station main body can be chiseled out simultaneously with the earthwork excavation under the protection of the L-shaped retaining wall on the station top plate, which shortens the chiseling operation period and reduces the chiseling operation construction risk. In the wall-mounted air duct, the floor slab, side wall and station main body can be connected and constructed integrally at one time, which directly optimizes and cancels the complex plane batch construction process of the post-poured band, maximally shortens the construction period, reduces the number of structural steel joints, improves the structural integrity, optimizes the construction joint, simplifies the structural waterproof and external waterproof treatment, and significantly improves the waterproof effect.

[0036] The mechanical equipment is used to replace the removal of the station enclosure and the lattice column, which shortens the construction period and improves the construction safety. The process conversion and structural stress system conversion are less frequent, which ensures the structural reliability of the wall-mounted air duct. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 FIG. 1 is a structural schematic diagram of a subway wall-mounted air duct construction method.

[0038] Figure 2 FIG. 2 is a structural schematic diagram of a wall-mounted air duct.

[0039] Figure 3 FIG. 3 is a structural schematic diagram of a wall-mounted air duct after the removal of a lattice column.

[0040] Figure 4 Process diagram for vertical support system construction.

[0041] Figure 5 Process diagram for construction of top plate.

[0042] Figure 6 Process diagram for construction of middle plate.

[0043] Figure 7 Process diagram for removal of negative one layer lattice column.

[0044] Figure 8 Process diagram for construction of bottom plate.

[0045] Figure 9 Process diagram for removal of negative two layer lattice column.

[0046] In the figure:

[0047] 1, station main body; 2, L-shaped retaining wall; 3, station crown beam; 4, top plate; 5, cover excavation support crown beam; 6, cantilever half pile; 7, air duct enclosure pile; 8, side wall; 9, lattice column; 10, middle plate; 11, middle column; 12, station enclosure pile; 13, bottom plate; 14, vertical column pile; 15, layer plate. DETAILED DESCRIPTION

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the present application will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the drawings structure is only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor. It should be noted that the description of these embodiments is used to help understand the present application, but does not constitute a limitation on the present application.

[0049] Embodiment 1:

[0050] As shown in the figure, a subway wall-mounted air duct construction method comprises the following steps: Figures 1-9

[0051] S100: Construction of subway station main body 1.

[0052] Among them, the wall-mounted air duct is an accessory structure of the subway station, so the subway station main body 1 part is constructed first, and after the construction of the subway station main body 1 part is completed, the construction of the accessory structure is started.

[0053] S200: Construction of L-shaped retaining wall 2.

[0054] ​The L-shaped retaining wall 2 can shorten the length of the wall-mounted air duct, thereby reducing the engineering cost. The L-shaped retaining wall 2 can also serve as an abutment, thereby playing a role of protecting the abutment and connection. Meanwhile, the L-shaped retaining wall 2 is a cantilever retaining wall, and after the construction is completed, the earthwork needs to be backfilled to stabilize the L-shaped retaining wall 2.

[0055] Further, step S200: the L-shaped retaining wall 2 construction includes the following steps:

[0056] S201: The L-shaped retaining wall 2 is constructed on the station roof 4, and the L-shaped retaining wall 2 is close to the inner side of the station corbel 3;

[0057] S202: After the L-shaped retaining wall 2 reaches the design strength, the earthwork is backfilled in layers;

[0058] S203: The earthwork is rolled.

[0059] It is easy to understand that the backfilled earthwork is preferably the earthwork excavated before the construction, thereby achieving the reuse and helping to reduce the engineering cost.

[0060] Correspondingly, the station main body 1 includes the station roof 4 and the station corbel 3. Based on this, the position of the L-shaped retaining wall 2 is limited to improve the structural strength of the L-shaped retaining wall 2, so as to form a temporary support system in cooperation with the vertical support system in the later period, thereby playing a supporting role in the wall-mounted air duct structure construction process.

[0061] S300: The vertical support system construction.

[0062] During the wall-mounted air duct structure construction process, the vertical support system plays a supporting role. After the wall-mounted air duct structure construction is completed, at least part of the vertical support system can be removed, thereby achieving the underpinning of the support structure and making the wall-mounted air duct unobstructed for subsequent use.

[0063] The L-shaped retaining wall 2 and the vertical support system form a temporary support system, which replaces the enclosure structure in the prior art. Based on the supporting force provided by the L-shaped retaining wall 2 and the structural strength of the wall-mounted air duct after reaching the design strength, at least part of the vertical support system can be removed at one time. Compared with the prior art, the number of breaking times is greatly reduced, the number and difficulty of waterproof operations are reduced, the construction period is shortened, and the engineering cost is reduced.

[0064] Further, step S300: the vertical support system construction includes the following steps:

[0065] S301: The lattice column 9 and the station enclosure structure are constructed;

[0066] S302: The corbel shallow foundation pit is excavated;

[0067] S303: The cantilever half pile 6, the pile top corbel of the cantilever half pile 6, and the cover-excavation support corbel 5 are constructed.

[0068] Based on the above design scheme, the lattice column 9 is cheap in cost and simple in process, replaces the high-cost cover-excavation steel pipe column used in the prior art, and helps to reduce the engineering cost.

[0069] As shown in Figure 2 and Figure 3 , the station enclosure structure includes station enclosure piles 12 and air duct enclosure piles 7, and the lattice columns 9 are located between the station enclosure piles 12 and the air duct enclosure piles 7. Based on this, the vertical support system has multiple support points abutting the hanging air duct, provides effective support, reduces the number of lattice columns 9, has a larger spacing between adjacent lattice columns 9, and facilitates the passage in the hanging air duct, which facilitates the entry of mechanical equipment, and the lattice columns 9 are removed by the mechanical equipment, which can increase the removal efficiency and reduce the risk of removal operation.

[0070] Preferably, the temporary support system includes L-shaped retaining walls 2, cantilever half piles 6, cover-excavation support crown beams 5, and lattice columns 9. Based on this, under the protection of the L-shaped retaining walls 2 on the station roof 4, the station enclosure structure can be removed synchronously with the earthwork excavation to shorten the removal operation period and reduce the risk of removal operation construction. At the same time, during the construction of the hanging air duct structure, the temporary support structure provides support force to maintain the design shape of the hanging air duct. In addition, after the completion of the construction of the hanging air duct structure, the parts of the temporary support system except the lattice columns 9 can be retained and used as a connecting structure between the hanging air duct and the station main body 1.

[0071] In one possible implementation, the station enclosure structure includes station enclosure piles 12 and air duct enclosure piles 7, the station enclosure piles 12 are connected to the station main body 1, and the air duct enclosure piles 7 are arranged opposite the station enclosure piles 12; the crown beam shallow foundation pit is provided with the air duct enclosure piles 7, and the cantilever half piles 6 and the cover-excavation support crown beams 5 are arranged on the top surface of the air duct enclosure piles 7.

[0072] Based on the above design scheme, the station enclosure piles 12 and the air duct enclosure piles 7 are each provided with a plurality of piles, and the station enclosure piles 12 and the air duct enclosure piles 7 are respectively arranged at equal intervals on the same straight line, wherein the station enclosure piles 12 and the air duct enclosure piles 7 at both ends respectively extend to the outside of the hanging air duct. During the construction of the hanging air duct structure, the station enclosure piles 12 and the air duct enclosure piles 7 located in the hanging air duct are simultaneously subjected to removal operation, which on the one hand shortens the removal operation period and reduces the risk of removal operation, and on the other hand eliminates the separation structure between the station main body 1 and the hanging air duct, so as to facilitate the direct connection of the hanging air duct to the station main body 1, thereby improving the integrity of the structure.

[0073] In one possible implementation, a sand-filled layer is arranged above the lattice column 9, and a vertical column pile 14 is arranged below the lattice column 9 and located below the hanging air duct. Based on the above design scheme, when the top of the hanging air duct has a low load, as Figure 5As shown, the low load is added by setting the retaining wall, and the compaction degree of the retaining wall is tested by filling the sand layer. The column 14 is set for the straight support with long span to increase the support force, and is used for bearing the horizontal and vertical load.

[0074] S400: construction of the wall-mounted air duct structure.

[0075] It is easy to understand that the wall-mounted air duct has multiple layers, and the cover-excavation top-down method is used for construction in the present application. During the construction of the top layer of the wall-mounted air duct, the temporary support system is used as the support, and after the concrete wall and column of the layer of the wall-mounted air duct reach the design strength, the lattice column 9 can be removed, so as to realize the conversion of the support and stress system of the wall-mounted air duct structure.

[0076] The step S400 of the construction of the wall-mounted air duct structure includes the following steps:

[0077] S410: construction of the upper layer of the wall-mounted air duct; and the vertical support system in the layer of the wall-mounted air duct is broken;

[0078] S420: construction of the lower layer of the wall-mounted air duct;

[0079] S430: repeating the above steps.

[0080] Or, the step S400 of the construction of the wall-mounted air duct structure includes the following steps:

[0081] S410: top-down construction of the wall-mounted air duct layer by layer;

[0082] S420: breaking of the vertical support system.

[0083] Based on the above design scheme, the removal of the vertical support system (specifically, the lattice column 9) has two schemes. One is that, as shown in Figures 4-9 , the part of the lattice column 9 in each layer of the wall-mounted air duct is removed after the construction of the layer is completed, and the other is that, as shown in Figure 2 and Figure 3 , all of the lattice columns 9 are removed after the construction of all of the wall-mounted air ducts is completed. The former realizes the conversion of the support and stress system of the wall-mounted air duct structure layer by layer, increases the adaptation time of the wall-mounted air duct, and is helpful to improve the stability of the wall-mounted air duct structure; and the latter reduces the number of entries of the mechanical equipment and reduces the construction cost. Further, the construction personnel can choose one according to the actual situation.

[0084] Further, the step 410 of the construction of the wall-mounted air duct includes the following steps:

[0085] S411: excavating the earthwork to form a foundation pit, and chiseling the station enclosure structure;

[0086] S412: leveling the foundation pit;

[0087] S413: construction of the pit bottom concrete cushion;

[0088] S414: construction of the waterproof layer of the pit side wall 8;

[0089] S415: erection of the formwork support system and construction of the wall-hung air duct;

[0090] S416: removal of the formwork support system.

[0091] In step S411, the earthwork is excavated by mechanical equipment, and preferably, the earthwork is excavated to 2-2.4 meters below the top plate 4 to reserve space for the next step of excavation, and the protective construction of the cover-excavated top plate 4 is avoided, thereby saving the construction cost.

[0092] The chiseling operation is simultaneously performed when the earthwork is excavated, and the chiseled station enclosure structure is the station enclosure pile 12 and the air duct enclosure pile 7 located in the wall-hung air duct. The chiseling operation is performed simultaneously with the excavation of the pit to shorten the construction period. At the same time, the lattice column 9 of the pre-poured slab 15 beam segment is cleaned.

[0093] Compared with the prior art, the removal of the station enclosure structure is realized by mechanical equipment, which on the one hand avoids manual chiseling and improves the chiseling efficiency, and on the other hand makes the processing joint flat and reduces the difficulty of waterproof operation.

[0094] In step S413, the concrete cushion is applied to make the pit bottom flat and to protect the pit. Preferably, the thickness of the concrete cushion is 10-18 cm, and the specific thickness can be appropriately increased or decreased according to the actual construction conditions. Further, the concrete with a mark of C15, C20, C25 or C30 is selected. The specific concrete mark is also selected according to the actual construction conditions.

[0095] In step S414, the waterproof layer is prepared before the construction of the side wall 8 to prevent leakage. The upper and lower ends of the waterproof layer are connected to the top plate 4 and the lower side wall 8, respectively, and the construction is well done to facilitate subsequent construction.

[0096] In step S415, the construction of the wall-hung air duct of the layer is completed, and the construction range includes but is not limited to at least one of the slab 15, the side wall 8, the inner wall and the middle column 11. At the same time, the connection at the corresponding position of the station main body 1 is completed at one time during the construction of the wall-hung air duct, and the structure is well done to the next layer. Among them, for the two-layer wall-hung air duct, the slab 15 includes the top plate 4, the middle plate 10 and the bottom plate 13.

[0097] In step S416, when the slab 15, the side wall 8, the inner wall and the middle column 11 in the wall-hung air duct of the layer reach the design strength, the formwork support system is removed to facilitate the construction of the wall-hung air duct of the next layer.

[0098] After the last layer of the wall-mounted air duct reaches the structural design strength, the latticed column 9 can be removed, the overall structure underpinned, and the next step of construction can be performed after the structure is stable. Specifically:

[0099] The wall-mounted air duct construction of step 410 further includes the following steps:

[0100] S417: backfilling and covering;

[0101] S418: rolling construction.

[0102] That is, the subway wall-mounted air duct construction method absorbs the construction idea of the top-down method, and is constructed under the condition of no covering or low load. After the construction is completed, the wall-mounted air duct structure strength reaches the design requirement, and the backfilling and covering and rolling construction can be performed to restore the original site conditions.

[0103] Example 2:

[0104] Taking the construction process of a two-layer wall-mounted air duct as an example, the wall-mounted air duct structure construction of step S400 is further described:

[0105] Excavate the earthwork to 2 meters below the top-down top plate 4, and simultaneously remove the station enclosure structure according to the earthwork excavation progress. At the same time, the latticed column 9 pre-poured into the top plate 4 beam segment is cut off to ensure the integrity of the top plate 4 structure. In addition, the welding of the column top flange pre-anchored into the top plate 4 beam is completed.

[0106] Level the original soil of the foundation pit, and construct a 15 cm thick C20 plain concrete cushion.

[0107] Apply the waterproof layer of the side wall 8 and sling the side wall 8 to the top plate 4 and the negative layer.

[0108] Build a formwork support system to construct the top plate 4, which is connected to the top plate 4 of the station body 1 in one time, and the structure is slung to the negative layer side wall 8, the inner wall, and the middle column 11.

[0109] After the strength of the top plate 4 reaches the design demolding strength, the support formwork system is removed.

[0110] Excavate the earthwork to 2 meters below the top-down middle plate 10, and simultaneously remove the station enclosure structure according to the earthwork excavation progress. At the same time, the latticed column 9 pre-poured into the middle plate 10 beam segment is cleaned.

[0111] Level the original soil of the foundation pit, and construct a 15 cm thick C20 plain concrete cushion.

[0112] Apply the waterproof layer of the side wall 8 and sling the side wall 8 to the top plate 4 and the negative layer.

[0113] The template support system is built to construct the middle plate 10, and the connection between the middle plate 10 and the middle plate 10 of the station main body 1 is completed at one time, and the structure of the wall column in the negative first and second floors is well shaken.

[0114] The negative first floor side wall 8, the inner wall and the middle column 11 are constructed.

[0115] After the middle plate 10, the negative first floor side wall 8, the inner wall and the middle column 11 reach the design strength of the formwork, the support template system is removed.

[0116] Excavate the earthwork to the cover-excavation bottom plate 13, and synchronously remove the station enclosure structure with the earthwork excavation progress. At the same time, the lattice column 9 pre-poured into the bottom plate 13 beam segment is cleaned.

[0117] Level the original soil of the foundation pit, and construct a 10cm-thick 15-element concrete cushion.

[0118] The waterproof layer of the side wall 8 is constructed and the negative second floor side wall 8 is shaken.

[0119] The waterproof protective layer is constructed.

[0120] The bottom plate 13 is constructed, and the connection between the bottom plate 13 and the floor of the station main body 1 is completed at one time, and the structure of the negative second floor side wall 8, the inner wall and the middle column 11 is well shaken.

[0121] The negative second floor side wall 8, the inner wall and the middle column 11 are constructed.

[0122] The lattice column 9 is removed after the hanging wall air duct reaches the structural design strength.

[0123] The top plate 4 is backfilled and compacted after the hanging wall air duct structure is stable.

[0124] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A construction method for a wall-mounted ventilation duct in a subway system, characterized in that, Includes the following steps: Construction of the main structure of the subway station (1); Construction of L-shaped retaining wall (2); Construction of the vertical support system; Construction of wall-mounted air duct structure; The wall-mounted air duct has multiple layers, and the construction of the wall-mounted air duct structure includes the following steps: construction of the upper layer of wall-mounted air duct; removal of the vertical support system inside the wall-mounted air duct of this layer; construction of the lower layer of wall-mounted air duct; repeating the above steps. Alternatively, the construction of the wall-mounted air duct structure includes the following steps: constructing the wall-mounted air duct layer by layer in reverse; dismantling the vertical support system; The construction of the vertical support system includes the following steps: Construction of lattice columns (9) and station enclosure structure; shallow foundation pit excavation for the crown beam; Construction of cantilever half pile (6), cantilever half pile (6) top capping beam and cut-and-cover support capping beam (5); The station enclosure structure includes station enclosure piles (12) and ventilation duct enclosure piles (7). The station enclosure piles (12) are connected to the main body of the station (1), and the ventilation duct enclosure piles (7) are set relative to the station enclosure piles (12). The ventilation duct enclosure piles (7) are provided below the shallow foundation pit of the cap beam. The cantilever half piles (6) and the cut-and-cover support cap beam (5) are both set on the top surface of the ventilation duct enclosure piles (7).

2. The construction method for subway wall-mounted ventilation ducts according to claim 1, characterized in that, The construction of the L-shaped retaining wall (2) includes the following steps: An L-shaped retaining wall (2) is constructed on the station roof slab (4), and the L-shaped retaining wall (2) is closely attached to the inner side of the station cap beam (3); After the L-shaped retaining wall (2) reaches the design strength, the earthwork is backfilled in layers; Compact the soil; Accordingly, the station body (1) includes the station roof slab (4) and the station cap beam (3).

3. The construction method for subway wall-mounted ventilation ducts according to claim 1, characterized in that, A sand-filled layer is provided above the lattice column (9), and a column pile (14) is provided below the lattice column (9), and the column pile (14) is located below the wall-mounted air duct.

4. The construction method for subway wall-mounted ventilation ducts according to claim 1, characterized in that, The construction of the wall-mounted air duct includes the following steps: excavating the earth to form a foundation pit and removing the station enclosure structure; leveling the foundation pit; constructing the concrete cushion layer at the bottom of the pit; constructing the waterproof layer of the side wall (8) of the foundation pit; erecting the formwork support system and constructing the wall-mounted air duct; dismantling the formwork support system.

5. The construction method for subway wall-mounted ventilation ducts according to claim 4, characterized in that, The earthwork is excavated to 2-2.4 meters below the top slab (4); the thickness of the concrete cushion layer is 10-18 cm, and concrete with grade C15, C20, C25 or C30 is selected.

6. The construction method for subway wall-mounted ventilation ducts according to claim 4, characterized in that, The construction of wall-mounted air duct structures also includes the following steps: backfilling with soil; compaction.

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