A construction method for rapid slag removal of underground excavation auxiliary structures of subway stations

Abstract

The present invention discloses a construction method for rapid slag removal of ancillary structures of a submerged subway station, comprising the following steps: constructing advance support at the station main body and the air duct horse head gate; constructing a shaft locking ring beam and a shaft slag hole; constructing the air duct from the station to the shaft using a step method; constructing a left guide tunnel on the air duct step to the slag hole; excavating the shaft to the shaft air duct horse head gate and installing three grids in the shaft; and excavating the remaining air ducts and shaft after the shaft and air duct are connected. The present invention provides a construction method for rapid slag removal using a submerged station construction channel by connecting the shaft slag hole with the station air duct, thereby changing the current situation of slow slag removal efficiency in the construction of station auxiliary shafts. During the construction process, slag removal efficiency can be greatly improved, and the construction cycle time can be shortened. The method has low requirements for the construction site, reduces the impact on the urban surface, and has little impact on the surrounding environment when transporting slag, and is not affected by weather. The method has lower risks than vertical slag removal, and is suitable for the construction of submerged station ancillary structures in urban areas.

Description

Technical Field

[0001] The invention belongs to the technical field of shaft excavation construction and tunnel construction, and particularly relates to a construction method for rapid slag removal of ancillary structures of a dark-excavated subway station. Background Art

[0002] Subways are now one of the most effective ways to address urban traffic congestion, and accelerating urban rail transit construction is becoming a consensus in a growing number of cities. Due to political, traffic, and environmental constraints, subway stations in central urban areas are often constructed using the underground excavation method. This disadvantage, however, is that station ancillary structures are often located close to surrounding structures, resulting in limited land availability. Researching a construction method that requires less floor space, requires less time, and reduces construction risks is highly beneficial.

[0003] Difficulty in solving the above technical problems:

[0004] The construction plan for the vertical shaft air duct of the station's auxiliary structure usually involves setting up a larger construction site on the ground to set up a slag storage area and slag discharge equipment such as gantry cranes. The construction sequence is to first open-cut the vertical shaft to the air duct position, then remove the air duct horse head gate and use the dark excavation method to connect the air duct to the main body of the station. The slag excavated from the vertical shaft and air duct is discharged by vertical lifting of the vertical shaft and temporarily stored in the slag storage area on the ground.

[0005] Typically, stations in busy urban areas are built beneath main roads, with auxiliary shaft ducts located within green belts on both sides of the road, close to surrounding structures and constraining construction space. Furthermore, auxiliary structures utilize conventional vertical hoisting methods for slag removal, which is inefficient and time-consuming. Each construction cycle is long, requiring a larger construction site for slag storage areas and presenting risks associated with vertical hoisting.

[0006] Therefore, it is of positive significance for the construction plan of the auxiliary structure to adopt a construction method that occupies less construction space, improves the slag discharge efficiency and reduces the risk of vertical lifting slag discharge. Summary of the Invention

[0007] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a construction method for quickly removing slag from the auxiliary structure of a dark-excavated subway station.

[0008] The technical solution of the present invention is: a construction method for quickly removing slag from ancillary structures of a dark-excavated subway station, comprising the following steps:

[0009] A. Construction of advanced support at the main station and the air duct gate;

[0010] B. Construction of shaft locking ring beam and shaft slag hole;

[0011] First, construct the shaft locking ring beam.

[0012] Finally, construct a shaft slag hole in a corner of the shaft;

[0013] C. Construct the air duct from the station to the shaft using the step method;

[0014] First, carry out advanced geological forecast of wind duct.

[0015] Then, the main support of the underground station within the Matou Gate was removed.

[0016] Then, the air duct was constructed from the station toward the shaft using the step method.

[0017] Finally, during the construction of the air duct, grid spray-mix support should be erected in a timely manner;

[0018] D. Use small cross-section to construct the air duct and connect it to the vertical shaft slag hole;

[0019] First, drill an advance exploration hole on the air duct face when the distance between the air duct face and the slag hole is L1.

[0020] Then, after the geological conditions are ascertained, the air duct is constructed to a point L2 from the slag leakage hole;

[0021] Finally, the left guide tunnel section of the upper step of the air duct is used to construct the slag leakage hole.

[0022] E. Construction of vertical shaft and installation of three grilles at the horse head gate of the vertical shaft air duct;

[0023] The vertical shaft was excavated using the inverted well wall method. When excavated to the horse head gate of the vertical shaft air duct, the vertical shaft was reinforced with three Lianli No. Ⅲ grids.

[0024] F. After the vertical shaft and air duct are excavated and connected, the remaining air ducts and vertical shafts are excavated.

[0025] Furthermore, in step A, the advance support of the station body and the air duct gate is constructed. The specific process is as follows:

[0026] When constructing the initial support of the underground excavation station main body, the advance support at the station main body and the air duct horse head gate is set up simultaneously, and the advance support at the station main body and the air duct horse head gate is completed before the construction of the underground excavation station main structure.

[0027] Furthermore, step B is to construct the shaft locking ring beam, and the specific process is as follows:

[0028] The slope method is used to construct the shaft lock ring beam. After the shaft lock ring beam reaches the design strength, the shaft slag hole is constructed.

[0029] Furthermore, step B is to construct the vertical shaft slag hole, and the specific process is as follows:

[0030] Mechanical drilling method is adopted to construct vertical shaft slag holes. According to the construction plan layout and the size of drilling machinery, the vertical shaft slag hole is set in a corner of the vertical shaft to facilitate the placement of drilling machinery and reduce the occupation of construction site. The vertical shaft slag hole is drilled to the depth of the air duct arch foot.

[0031] Furthermore, in step C, the air duct is constructed in the step method from the inside of the station toward the vertical shaft, and the initial support of the main body of the station is removed within the range of the air duct horse head door. The air duct horse head door is reinforced with three-frame No. 1 grids.

[0032] Furthermore, in step C, the air duct is constructed from the station to the shaft using the step method. The specific process of the step method is as follows:

[0033] The air duct is constructed using the step method, with the upper and lower steps being 3 to 5 meters in length. After excavation, grid-type sprayed concrete support is promptly erected. The excavated soil from the air duct is transported out through the underground construction channel inside the station until the face is excavated to the shaft slag hole L1.

[0034] Furthermore, the specific contents of step D, which uses a small-section air duct to construct and connect the air duct to the vertical shaft slag hole and drill an advance exploration hole on the tunnel face, are as follows:

[0035] The advance exploration hole of the air duct face includes at least one horizontal exploration hole, which is drilled horizontally and passes through the slag leakage hole;

[0036] The advance exploration hole of the air duct face includes at least one lateral horizontal exploration hole, which is drilled horizontally and avoids the slag leakage hole;

[0037] The advance exploration hole of the air duct face includes at least one exploration hole inclined upward, which is drilled obliquely upward through the upper part of the shaft horse head gate;

[0038] After drilling ahead at the air duct face to ascertain the ground and water volume ahead, construction can continue.

[0039] Furthermore, step D uses a small-section air duct to connect to the vertical shaft slag hole, including the following process:

[0040] When the excavation face of the air duct is at a distance of L2 from the shaft, temporary vertical supports and temporary invert arches are set up for the left guide tunnel of the upper step of the air duct, and the right guide tunnel of the upper step of the air duct is closed to close the face. The face is sealed with anchor rods, grids and sprayed concrete, and the lower step is counter-pressed with slag to form a counter-pressure backfill area of the lower step of the air duct. The excavation of the left guide tunnel of the upper step of the air duct is continued, and initial support is applied in time after excavation.

[0041] Furthermore, step D uses a small-section air duct to connect to the vertical shaft slag hole, including the following process:

[0042] When the left guide tunnel of the upper step of the air duct is constructed to the intersection of the guide tunnel and the vertical shaft, three No. II grids are set to strengthen the support at the horse head gate of the vertical shaft air duct. Then the left guide tunnel of the upper step of the air duct is constructed until it passes through the slag leakage hole of the vertical shaft, and the heading face of the left guide tunnel of the upper step of the air duct is closed. The heading face is closed with anchor rods, grids and spray mix.

[0043] Furthermore, in step E, during the construction of the vertical shaft and the installation of three grilles at the horse head gate of the vertical shaft air duct, the vertical shaft is excavated using the inverted shaft wall method, and timely support is provided after excavation. The debris leaks into the horizontal passage through the vertical shaft slag leakage holes and is then transported out by construction machinery through the internal construction passage of the station. When excavating to the horse head gate of the air duct, the vertical shaft is reinforced with three grilles installed at the horse head gate of the vertical shaft air duct.

[0044] The beneficial effects of the present invention are as follows:

[0045] The present invention solves the problems that the traditional construction scheme of the vertical shaft air duct of the auxiliary structure of the underground excavation station needs to occupy a large construction site, has a great impact on the surrounding area, and has slow slag removal efficiency and long slag removal time during excavation construction.

[0046] The present invention provides a construction method in which the auxiliary structure of a concealed subway station is connected to the station air duct through a vertical shaft slag leakage hole, and the slag is quickly discharged through the concealed station construction channel. This method changes the current situation in which vertical lifting is slow in efficiency for slag discharge during the construction of the auxiliary shaft of the station. During the construction process, the slag discharge efficiency can be greatly improved, the construction cycle time can be shortened, and the construction period can be saved. The method has low requirements for the construction site, reduces the impact on the urban surface, and the transportation of slag has little impact on the surrounding environment and is not affected by the weather. The method has less risk than vertical slag discharge, and is suitable for the construction of auxiliary structures of concealed subway stations in urban areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a plan view of the excavation and support of the vertical shaft air duct of the auxiliary structure in the present invention;

[0048] Figure 2 This is a cross-sectional view of the excavation support of the air duct step method in the present invention;

[0049] Figure 3 This is a longitudinal section of the station air duct horse head door advance support and the shaft slag hole in the present invention;

[0050] Figure 4 This is a longitudinal section of the air duct step method excavation support and advance exploration hole in the present invention;

[0051] Figure 5 This is a longitudinal section of the left pilot tunnel of the upper step of the air duct excavation and the backfill of the lower step under counter pressure in the present invention;

[0052] Figure 6 This is a longitudinal section view of the left guide tunnel excavated from the upper step of the air duct to the closure of the slag leakage hole in the present invention.

[0053] Figure 7 This is a longitudinal cross-sectional view of the vertical shaft excavation construction method using the inverted shaft wall method in the present invention;

[0054] Figure 8 It is a longitudinal cross-sectional view of the remaining portion of the vertical shaft air duct excavation in the present invention;

[0055] in:

[0056] 101 Main structure of underground station 102 Air duct section

[0057] 103 Left guide hole for the upper steps of the air duct 104 Right guide hole for the upper steps of the air duct

[0058] 105 Downstairs 106 Shaft

[0059] 107 Shaft slag hole 108 Shaft locking ring beam

[0060] 109 Main support of underground excavation station

[0061] 110 Advanced support at the station main body and the air duct horse head gate

[0062] 111 Ⅰ three-frame grille

[0063] 112 Air duct face advance drilling

[0064] 113 The right guide hole on the upper step of the air duct closes the tunnel face

[0065] 114 Temporary vertical support for the left guide hole of the upper steps of the air duct

[0066] 115 Temporary inverted arch of the left guide tunnel on the upper steps of the air duct

[0067] 116 Back pressure backfill area under the step of the air duct

[0068] 117 Ⅱ three-frame grille

[0069] 118 The left guide tunnel on the upper step of the air duct is closed

[0070] 119 Initial branch of the vertical shaft

[0071] 120 No. Ⅲ three-frame grille

[0072] 121 Remaining lower steps and remaining shafts of the air duct. DETAILED DESCRIPTION

[0073] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and embodiments:

[0074] like Figures 1 to 8 As shown, a construction method for quickly removing slag from ancillary structures of a subway station through underground excavation comprises the following steps:

[0075] A. Construction of the main station and the air duct horse head gate advanced support 110;

[0076] B. Construction of the shaft locking ring beam 108 and the shaft slag hole 107;

[0077] First, construct the shaft locking ring beam.

[0078] Finally, construct a shaft slag hole in a corner of the shaft;

[0079] C. Construct the air duct 102 from the station toward the shaft using the step method;

[0080] First, carry out advanced geological forecast of wind duct.

[0081] Then, the main support 109 of the underground station was removed within the Matoumen area.

[0082] Then, the air duct was constructed from the station toward the shaft 106 using the step method.

[0083] Finally, during the construction of the air duct, grid spray-mix support should be erected in a timely manner;

[0084] D. Use a small cross-section to construct the air duct and connect it to the vertical shaft slag hole 107;

[0085] First, when the distance between the air duct face and the slag hole L1 is set, the air duct face advance exploration hole 112 is set.

[0086] Then, after the geological conditions are ascertained, the air duct is constructed to a point L2 from the slag leakage hole;

[0087] Finally, the left guide tunnel 103 section on the upper step of the air duct is used to construct to the vertical shaft slag leakage hole 107.

[0088] E. Construction shaft and 106 three grilles are connected at the horse head gate of the shaft air duct;

[0089] The vertical shaft was excavated using the inverted well wall method. When excavated to the shaft air duct gate, the shaft was reinforced with three 120mm Lianli III grids.

[0090] F. After the vertical shaft and air duct are excavated and connected, the remaining air ducts and vertical shafts are excavated.

[0091] Step A involves constructing advance support for the station body and the air duct gate. The specific process is as follows:

[0092] When constructing the initial support 109 of the underground excavation station body, the advance support 110 at the station body and the air duct horse head gate is simultaneously set up, and the advance support at the station body and the air duct horse head gate is completed before the construction of the underground excavation station main structure 101.

[0093] Step B is to construct the shaft locking ring beam. The specific process is as follows:

[0094] The vertical shaft locking ring beam 108 is constructed by the slope reduction method. After the vertical shaft locking ring beam 108 reaches the designed strength, the vertical shaft slag leakage hole 107 is constructed.

[0095] Step B is to construct the vertical shaft slag hole. The specific process is as follows:

[0096] The vertical shaft slag hole 107 is constructed by mechanical drilling method. The vertical shaft slag hole is set at a corner of the vertical shaft. The vertical shaft slag hole 107 is drilled to a depth of the air duct arch foot.

[0097] Specifically, the vertical shaft slag hole 107 should be set according to the construction plan layout and the size of the hole-making machinery, taking into account the floor space occupied by the machinery. Therefore, the vertical shaft slag hole 107 is set in a corner of the vertical shaft.

[0098] Specifically, the diameter of the vertical shaft slag leakage hole 107 is 800-1200 mm.

[0099] Furthermore, in step C, the air duct is constructed in the step method from the inside of the station toward the vertical shaft, and the initial support of the station body excavated within the range of the air duct horse head door is removed. The air duct horse head door is reinforced with three-frame grid 111 of Joint No. 1.

[0100] Step C: Construct the air duct from the station to the shaft using the step method. The specific process is as follows:

[0101] The air duct is constructed using the step method, with the upper and lower steps being 3 to 5 meters in length. After excavation, grid-type sprayed concrete support is promptly erected. The excavated soil from the air duct is transported out through the underground construction channel inside the station until the face is excavated to the shaft slag hole L1.

[0102] Specifically, in step C, the removal of the primary support 109 of the underground station body within the range of the horse head gate should be carried out after the strength of the secondary lining of the station body reaches the design strength.

[0103] Specifically, L1 is the distance between the tunnel face and the slag leakage hole in the vertical shaft, which is 10-15m.

[0104] The specific contents of step D, which uses a small-section air duct to construct and connect the air duct to the vertical shaft slag hole and drill the air duct face advance exploration hole 112, are as follows:

[0105] The advance exploration hole of the air duct face includes at least one horizontal exploration hole, which is drilled horizontally and passes through the slag leakage hole;

[0106] The advance exploration hole of the air duct face includes at least one lateral horizontal exploration hole, which is drilled horizontally and avoids the slag leakage hole;

[0107] The advance exploration hole of the air duct face includes at least one exploration hole inclined upward, which is drilled obliquely upward through the upper part of the shaft horse head gate;

[0108] After drilling ahead at the air duct face to ascertain the ground and water volume ahead, construction can continue.

[0109] Specifically, the number of the advance exploration holes 112 on the air duct face is 3-5, and the length of the advance exploration holes 112 on the air duct face is 10-15 meters.

[0110] Step D uses a small-section air duct to connect to the vertical shaft slag hole, including the following process:

[0111] When the excavation face of the air duct is at a distance from the position L2 of the shaft, a temporary vertical support 114 and a temporary invert 115 are set up for the left guide tunnel of the upper step of the air duct, and the right guide tunnel of the upper step of the air duct is closed to close the face 113. The face is sealed with anchor rods, grids and sprayed concrete, and the lower step 105 is back-pressed with slag to form a back-pressure backfill area 116 of the lower step of the air duct. The excavation of the left guide tunnel of the upper step of the air duct is continued, and initial support is applied in time after excavation.

[0112] Step D uses a small-section air duct to connect to the vertical shaft slag hole, including the following process:

[0113] When the left guide tunnel of the upper step of the air duct is constructed to the intersection of the guide tunnel and the vertical shaft, three grids 117 of No. II are installed in the air duct at the horse head gate of the vertical shaft air duct, and the left guide tunnel 103 of the upper step of the air duct is constructed to pass through the slag leakage hole of the vertical shaft. The left guide tunnel of the upper step of the air duct is closed at the heading face 118, and the heading face is closed with anchor rods, grids and spray mix.

[0114] Specifically, in step D, a small-section air duct is constructed and connected to the vertical shaft slag hole. When constructing to the slag hole, attention should be paid to rockfall in the slag hole, and weak blasting and other measures should be taken to reduce over-blasting, avoid collapse, water leakage and other adverse consequences, and better linkage and related construction measures should be taken to ensure construction safety. Monitoring should be strengthened during the construction process. If any abnormality is found, construction should be stopped immediately and backfilled with counter pressure.

[0115] Specifically, L2 is the distance between the tunnel face and the shaft, which is 4 to 6 meters.

[0116] In step E, during the process of constructing the vertical shaft and setting up three grids at the horse head gate of the vertical shaft air duct 106, the vertical shaft is excavated using the inverted shaft wall method. After excavation, the initial support 119 of the vertical shaft is constructed in a timely manner. The slag is leaked into the horizontal passage through the vertical shaft slag leakage hole and then transported out through the internal construction passage of the station; when excavating to the horse head gate of the air duct, the vertical shaft is reinforced with three grids 120 of No. III.

[0117] Step F: After the shaft and the air duct are connected, the remaining air ducts and shafts are excavated. The specific process is as follows:

[0118] After the shaft is excavated to the upper step of the air duct, the excavation and support of the right guide tunnel 104 of the upper step of the air duct is completed from the station to the shaft, and then the excavation and support of the remaining lower steps of the air duct and the remaining shaft 121 are completed. Finally, the excavation and support of the remaining shaft are completed and the shaft bottom plate is closed.

[0119] In step A, advance support is set up at the interface between the main structure and the air duct, and the secondary lining of the station body is constructed to reduce the risk of opening the horse head gate.

[0120] In step B, a shaft cap beam is constructed and set up. The shaft cap beam strengthens the initial support and settlement resistance of the ground and the shaft during construction, reducing the construction risk during subsequent excavation.

[0121] In step C, the advanced geological forecast is carried out to ascertain the geological conditions of the strata ahead. After the horse head gate of the station air duct is removed, three grids are used to strengthen the support of the air duct. The air duct is excavated using the step method, which is divided into two steps, upper and lower. By adopting the layered staggered excavation method, the excavation height is reduced at one time, which reduces the construction risk compared with full-section excavation.

[0122] In step D, when the excavation of the air duct face is at the position L1 away from the leakage hole, an advance exploration hole is used to further explore the geological conditions at the horse head gate of the shaft. When the excavation of the air duct face is at the position L2 away from the shaft, the right pilot tunnel face of the upper step is closed, and the face is sealed with anchor rods, grids, and shotcrete. The lower step is backfilled with slag backpressure. Only the left pilot tunnel of the upper step is excavated, and a small-section excavation is used to connect the leakage hole. Three No. Ⅱ grids 117 are connected at the horse head gate of the vertical shaft air duct to strengthen the support of the air duct horse head gate and reduce the risk of excavation construction.

[0123] In step E, the vertical shaft is constructed using the inverted shaft wall method. The slag leaks into the horizontal channel through the slag leakage holes and is then transported out through the internal construction channel of the station. Compared with vertical lifting slag discharge, this method improves slag discharge efficiency, saves slag discharge time, and reduces the risk of vertical lifting slag discharge. At the same time, there is no need to set up slag discharge equipment such as gantry cranes and ground slag storage areas, which reduces the requirements for the construction site and reduces the impact on the surrounding surface environment.

[0124] The three No. Ⅲ grilles 120 connected at the horse head gate of the shaft air duct strengthen the shaft support and reduce the construction risk at the horse head gate.

[0125] like Figure 1 、 Figure 3 As shown, when constructing the initial support 109 of the underground excavation station body, the advance support 110 at the station body and the air duct horse head gate is simultaneously set from the interface between the station body and the air duct, and the secondary lining of the underground excavation station main structure 101 of the station is constructed; the shaft locking ring beam 108 is constructed, and then the shaft slag hole 107 is constructed by mechanical method. The diameter of the slag hole is 800~1200mm, and the depth of the slag hole can be set to the position of the air duct arch foot. Considering the size of the construction machinery, the slag hole is set in a corner of the shaft.

[0126] like Figure 1 、 Figure 2 、 Figure 4 、 Figure 5 、 Figure 6 As shown, after the secondary lining strength of the station body reaches the design strength, advance geological prediction of the air duct should be made, and then the initial support of the station body in the horse head gate range should be removed to excavate the air duct. The three No. Ⅰ grilles 111 are used to strengthen the support of the air duct at the station body and the horse head gate of the air duct, and the step method is used to construct the air duct.

[0127] like Figure 7 、 Figure 8 As shown, the vertical shaft 106 was excavated using the inverted shaft wall method. After excavation, timely support was provided, allowing the debris to leak into the horizontal passage through the slag holes and then be transported out through the station's internal construction channel. When excavation reached the top of the air duct, three No. Ⅲ grids 120 were installed at the shaft's duct gate to reinforce support. During construction, constant attention should be paid to the stratum geology and groundwater conditions. If significant water seepage occurs during excavation, timely sealing and grouting should be carried out to ensure compaction behind the initial support of the vertical shaft. Weak blasting technology should be used for vertical shaft excavation.

[0128] like Figure 8 As shown, after the shaft is excavated to the upper step of the air duct, the excavation and support of the right guide tunnel 104 of the upper step of the air duct is completed first from the station to the shaft, and then the excavation and support of the remaining lower steps of the air duct are completed, and then the excavation and support of the remaining shaft are completed, and the shaft bottom plate is closed.

[0129] The present invention solves the problems that the traditional construction scheme of the vertical shaft air duct of the auxiliary structure of the underground excavation station needs to occupy a large construction site, has a great impact on the surrounding area, and has slow slag removal efficiency and long slag removal time during excavation construction.

[0130] The present invention provides a construction method in which the auxiliary structure of a concealed subway station is connected to the station air duct through a vertical shaft slag leakage hole, and the slag is quickly discharged through the concealed station construction channel. This method changes the current situation in which vertical lifting is slow in efficiency for slag discharge during the construction of the auxiliary shaft of the station. During the construction process, the slag discharge efficiency can be greatly improved, the construction cycle time can be shortened, and the construction period can be saved. The method has low requirements for the construction site, reduces the impact on the urban surface, and the transportation of slag has little impact on the surrounding environment and is not affected by the weather. The method has less risk than vertical slag discharge, and is suitable for the construction of auxiliary structures of concealed subway stations in urban areas.

Claims

1. A construction method for rapid slag removal of underground excavation of subway station auxiliary structures, characterized by: The following steps are involved: (A) Construction of advanced support at the main station and the air duct gate; (B) Construction of shaft locking ring beam and shaft slag hole; First, construct the shaft locking ring beam. Finally, construct a shaft slag hole in a corner of the shaft; (C) Construct the air duct from the station to the shaft using the step method; First, carry out advanced geological forecast of wind duct. Then, the main support of the underground station within the Matou Gate was removed. Then, the air duct was constructed from the station toward the shaft using the step method. Finally, during the construction of the air duct, grid spray-mix support should be erected in a timely manner; (D) Use a small-section air duct to connect to the vertical shaft slag hole; First, drill an advance exploration hole on the air duct face when the distance between the air duct face and the slag hole is L1. Then, after the geological conditions are ascertained, the air duct is constructed to a point L2 from the slag leakage hole; Finally, the left guide tunnel section of the upper step of the air duct is constructed to the slag leakage hole; (E) Construction of a vertical shaft and installation of three grilles at the shaft air duct gate; The vertical shaft was excavated using the inverted well wall method. When excavated to the horse head gate of the vertical shaft air duct, the vertical shaft was reinforced with three Lianli No. Ⅲ grids. (F) After the vertical shaft and the air duct are excavated and connected, the remaining air ducts and vertical shafts are excavated; When constructing the primary support (109) of the underground excavation station body, the advanced support (110) at the station body and the air duct horse head gate is simultaneously set from the interface between the station body and the air duct, and the secondary lining of the underground excavation station main structure (101) of the station is constructed; the shaft locking ring beam (108) is constructed, and then the shaft slag hole (107) is constructed by mechanical method. The diameter of the slag hole is 800~1200mm, and the depth of the slag hole can be set to the position of the air duct arch foot. Considering the size of the construction machinery, the slag hole is set at a corner of the shaft; After the secondary lining strength of the station body reaches the design strength, the air duct is predicted in advance, and then the station body in the horse head gate area is removed to excavate the air duct. The air duct is reinforced by three No. Ⅰ grids (111) connected at the station body and the horse head gate of the air duct, and the air duct is constructed by the step method.

2. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 1, characterized in that: Step (A) is to construct the advance support of the station body and the air duct gate. The specific process is as follows: When constructing the initial support of the main body of the underground excavation station, the advance support at the station main body and the air duct horse head gate is set up simultaneously, and the advance support at the station main body and the air duct horse head gate is completed before the construction of the main structure of the underground excavation station.

3. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 1, characterized in that: Step (B) constructs the shaft locking ring beam. The specific process is as follows: The slope method is used to construct the shaft lock ring beam. After the shaft lock ring beam reaches the design strength, the shaft slag hole is constructed.

4. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 3, characterized in that: Step (B) constructs the vertical shaft slag hole, and the specific process is as follows: Mechanical drilling method is adopted to construct vertical shaft slag holes. According to the construction plan layout and the size of drilling machinery, the vertical shaft slag hole is set in a corner of the vertical shaft to facilitate the placement of drilling machinery and reduce the occupation of construction site. The vertical shaft slag hole is drilled to the depth of the air duct arch foot.

5. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 1, characterized in that: Step (C) Use the step method to construct the air duct from the station toward the shaft, remove the initial support of the station body excavated within the range of the air duct horse head door, and use three-piece Lianli No. 1 grille to strengthen the support of the air duct horse head door.

6. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 1, characterized in that: Step (C) The air duct is constructed by the step method from the station to the shaft. The specific process of the step method is as follows: The air duct is constructed using the step method, with the upper and lower steps being 3 to 5 meters in length. After excavation, grid-type sprayed concrete support is promptly erected. The excavated soil from the air duct is transported out through the underground construction channel inside the station until the face is excavated to the shaft slag hole L1.

7. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 1, characterized in that: Step (D) uses a small-section air duct to construct and connect the air duct to the vertical shaft slag hole to drill an advance exploration hole on the tunnel face. The specific contents are as follows: The advance exploration hole of the air duct face includes at least one horizontal exploration hole, which is drilled horizontally and passes through the slag leakage hole; The advance exploration hole of the air duct face includes at least one lateral horizontal exploration hole, which is drilled horizontally and avoids the slag leakage hole; The advance exploration hole of the air duct face includes at least one exploration hole inclined upward, which is drilled obliquely upward through the upper part of the shaft horse head gate; After drilling ahead at the air duct face to ascertain the ground and water volume ahead, construction can continue.

8. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 1, characterized in that: Step (D) uses a small-section air duct to connect to the vertical shaft slag hole, including the following process: When the excavation face of the air duct is at a distance of L2 from the shaft, temporary vertical supports and temporary invert arches are set up for the left guide tunnel of the upper step of the air duct, and the right guide tunnel of the upper step of the air duct is closed to close the face. The face is sealed with anchor rods, grids and sprayed concrete, and the lower step is counter-pressed with slag to form a counter-pressure backfill area of the lower step of the air duct. The excavation of the left guide tunnel of the upper step of the air duct is continued, and initial support is applied in time after excavation.

9. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 1, characterized in that: Step (D) uses a small-section air duct to connect to the vertical shaft slag hole, including the following process: When the left guide tunnel of the upper step of the air duct is constructed to the intersection of the guide tunnel and the vertical shaft, three No. II grids are set to strengthen the support at the horse head gate of the vertical shaft air duct. Then the left guide tunnel of the upper step of the air duct is constructed until it passes through the slag leakage hole of the vertical shaft, and the heading face of the left guide tunnel of the upper step of the air duct is closed. The heading face is closed with anchor rods, grids and spray mix.

10. The method for rapid slag removal of underground excavation auxiliary structures of a subway station according to claim 1, characterized in that: In step (E), during the construction of the vertical shaft and the installation of three grids at the shaft air duct horse head gate, the vertical shaft is excavated using the inverted shaft wall method. After excavation, timely support is provided, and the debris is leaked into the horizontal passage through the vertical shaft slag leakage holes and then transported out by construction machinery through the station's internal construction passage. When excavating to the air duct horse head gate, the vertical shaft is reinforced with three grids installed at the vertical shaft air duct horse head gate.

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