Multi-working-face construction ventilation method for ultra-deep shaft work area of extra-long railway tunnel

Abstract

The invention relates to an extra-long railway tunnel ultra-deep shaft work area multi-working-face construction ventilation method which comprises the steps that a ventilation system structure in a work area is determined through characteristic pollutant transportation simulation according to a work area model; corresponding air door switches are controlled according to different construction scenes; the axial flow fan set is arranged in the ventilation duct, and the ventilation duct is located between the auxiliary shaft and the auxiliary shaft parking lot. The jet fan is arranged in a haulage roadway of a main shaft yard; the air pipe is led out by the axial flow fan unit to be laid along the wall surface of the main tunnel, penetrates through the hard air walls in the two transverse channels closest to the ventilation channel and is laid towards the small mileage direction and the large mileage direction along the wall surface of the parallel guide, and the main tunnel and the parallel guide are arranged in parallel; the hard ventilation walls are arranged in the ventilation channel and the two transverse channels closest to the ventilation channel. The temporary air doors are arranged in the two transverse channels which are secondarily close to the ventilation channel; and the linkage air doors are arranged in two haulage roadways of the auxiliary shaft parking lot.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction ventilation, and specifically to a multi-face construction ventilation method for an ultra-deep shaft work area in a super-long railway tunnel. Background Technique

[0002] The statements in this part only provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] When the mountain body crossed by a super-long railway tunnel is thick, the transverse gully is not developed, and the transverse tunnel and inclined shaft in the middle of the tunnel are too long, making it difficult to accelerate the tunnel excavation construction progress, it is necessary to set up a shaft in the middle of the tunnel to open up a shaft work area to speed up the construction of the main tunnel and shorten the construction period. Super-long railway tunnels are usually buried deep, resulting in a large depth of the construction shaft. There are already engineering cases with a depth exceeding 700m.

[0004] During the construction of such tunnels, if the tunnel shaft underground work area is set up with two shafts, it usually has a bottom circular yard, a main tunnel roadway and a parallel heading roadway. And the bottom circular yard is respectively connected to the main tunnel roadway, the parallel heading roadway and the main and auxiliary shaft shafts, forming a complex spatial structure of multi-face intersection and connection in the underground work area. Affected by factors such as the vertical vertical transportation construction method and the longest ventilation limit distance, the traditional forced ventilation is not applicable to the tunnel shaft work area set up with two shafts (especially during the construction stage before being connected to the adjacent work area). Therefore, the roadway ventilation method is usually adopted for the ventilation and sewage discharge of the working face during the normal construction period of the tunnel shaft work area set up with two shafts.

[0005] At the same time, there is often a large elevation difference in the tunnel shaft work area. The loss of fresh air introduced into the underground work area through air ducts or shafts increases along the way. The wellhead is usually in a high-altitude area with thin air, and a larger ventilation air volume is required to meet the normal ventilation and air exchange of the operating personnel in the driving roadway of the underground work area and the dust removal and temperature reduction in the construction environment. In addition, the spatial structure of multi-faces and multi-intersection areas formed by the interconnected multi-chambers leads to chaotic development of the polluted air flow, and pollutants in the working face are easily retained in the chambers, resulting in relatively poor overall ventilation and sewage discharge efficiency. Summary of the Invention

[0006] In order to solve the technical problems existing in the above background technique, the present invention provides a multi-face construction ventilation method for an ultra-deep shaft work area in a super-long railway tunnel. According to the construction scenario requirements of different multi-faces, the roadway ventilation system in different states is turned on, so as to meet the ventilation and sewage discharge requirements under different multi-face construction scenarios. By optimizing the roadway ventilation air flow organization under different construction scenarios in the ultra-deep shaft work area, the ventilation control effect of pollutants is improved, providing a reference for formulating the ventilation control strategy for the underground work area of the ultra-deep shaft in the super-long railway tunnel and the construction site of similar projects.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The present invention provides a multi-working face construction ventilation method for an ultra-deep vertical shaft work area of ​​an extra-long railway tunnel, comprising the following steps:

[0009] Establish a model based on the parameters of the work area, simulate the transport of characteristic pollutants under the set boundary conditions, and determine the layout structure of the ventilation system in the work area based on the simulation results;

[0010] According to different working surface construction scenarios, switch the corresponding damper switch in the ventilation system;

[0011] The layout structure of the ventilation system includes:

[0012] The axial flow fan unit is arranged in the ventilation duct, which is located between the auxiliary shaft and the auxiliary shaft yard; the jet fan is arranged in the transport lane of the main shaft yard;

[0013] The air duct is led out from the axial flow fan unit and laid along the wall of the main tunnel. After passing through the hard wind wall, the air duct is laid along the wall of the flat guide towards the direction of small mileage and large mileage respectively. The main tunnel and the flat guide are arranged in parallel.

[0014] The hard wind wall is arranged in the ventilation duct and the two horizontal passages closest to the ventilation duct; the temporary dampers are arranged in the two horizontal passages closest to the ventilation duct; the interlocking dampers are respectively arranged in the two transport lanes of the auxiliary shaft yard, and each group of interlocking dampers includes two interlockingly controlled dampers. During the operation, at least one of the two dampers remains closed.

[0015] Furthermore, according to different construction working face scenarios and actual traffic needs, the corresponding dampers are switched on or off, and the axial flow fan is enabled to introduce fresh air from the outside through the ventilation duct and the auxiliary shaft, and the fresh air is sent to the working face through the air duct. The jet fan is opened and closed according to actual conditions to drive the generated polluted air to be discharged through the main shaft.

[0016] Furthermore, the model established according to the work area parameters includes the following steps:

[0017] The main tunnel and the horizontal guide are arranged in parallel, and there are multiple sets of cross passages between the main tunnel and the horizontal guide. The cross passages along the direction of small mileage are X01, X02...Xn, and the cross passages along the direction of large mileage are D01, D02...Dn;

[0018] There are transport lanes facing the long mileage and short mileage directions between the bottom of the main shaft and the horizontal guide. Each group of transport lanes is equipped with a corresponding slag transfer yard. The transport lanes in two directions and the horizontal guide form a circular main shaft yard, which is connected to the main shaft.

[0019] There are transportation roadways between the bottom end of the auxiliary shaft and the main tunnel, which are respectively oriented towards the large mileage and small mileage directions. There is also a ventilation duct between the two groups of transportation roadways. The transportation roadways in both directions and the main tunnel form an annular auxiliary shaft yard, which is connected to the auxiliary shaft.

[0020] Furthermore, in each group of interlocking air doors, the air door closer to the main tunnel is a normally closed air door, and the other air door is a normally open air door.

[0021] Furthermore, the bottom of the shaft of the auxiliary shaft is the underground horsehead gate roadway, which is connected to the shaft of the auxiliary shaft. The upper space of the horsehead gate roadway is connected to the large-section ventilation duct arranged horizontally through a small-section ventilation duct with a set inclination angle. The axial flow fan is arranged in the large-section ventilation duct arranged horizontally.

[0022] Furthermore, the rigid air wall is prepared from rigid materials. The rigid air wall is hermetically connected to the air duct. The rigid air wall is used to block the gas from flowing through the passage in the space outside the air duct.

[0023] Furthermore, the interlocking air door device is a pressureless air door, including at least two interlocking air doors. The two air doors have a set spacing. When one air door is closed, the other air door is interlocked to open. During the operation process, at least one of the two air doors is in a closed state.

[0024] Furthermore, the multi-face construction scenario includes a two-way four-face construction scenario. In the two-way four-face construction scenario, the axial flow fan group is started, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation air duct.

[0025] During construction, the temporary air door remains open. In each group of interlocking air doors, at least one air door remains closed.

[0026] When the difference in the driving construction progress of the opposite working faces in the pilot tunnel or the main tunnel exceeds the set range, the jet fan at the slag transfer yard entrance on the side with the faster construction progress is turned on to balance the air pressure of the air flow by diverting the polluted air.

[0027] Furthermore, the multi-face construction scenario includes a two-way two-face construction scenario. In the two-way two-face construction scenario, the axial flow fan group is started, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation air duct.

[0028] During construction, if there is a construction working face in the main tunnel, the temporary air door facing the construction direction of the main tunnel remains open. Otherwise, the temporary air door remains closed. In each group of interlocking air doors, at least one air door remains closed.

[0029] When the difference in the driving construction progress of the opposite working faces in the pilot tunnel or the main tunnel exceeds the set range, the jet fan at the slag transfer yard entrance on the side with the faster construction progress is turned on to balance the air pressure of the air flow by diverting the polluted air.

[0030] Further, the multi-face construction scenario also includes a two-way three-face construction scenario. In the two-way three-face construction scenario, the axial flow fan unit starts, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation air duct.

[0031] During construction, if there is a construction working face in the main tunnel, the temporary air door facing the construction direction of the main tunnel remains open; otherwise, the temporary air door remains closed. Among each group of interlocking air doors, at least one air door remains closed.

[0032] The jet fan on one side of the two-face construction is turned on for directional drainage of sewage.

[0033] Further, the multi-face construction scenario also includes a one-way two-face construction scenario. In the one-way two-face construction scenario, the axial flow fan corresponding to the construction side is turned on, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation air duct.

[0034] During construction, the temporary air door in the construction direction remains open, and the temporary air door in the non-construction direction is closed. Among the interlocking air doors, at least one air door remains closed.

[0035] The jet fan on one side of the two-face construction is turned on for directional drainage of sewage.

[0036] Further, in addition to the multi-face construction scenario, there is also a single-face construction scenario. In the single-face construction scenario, the axial flow fan corresponding to the construction side is turned on, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation air duct.

[0037] During construction, if there is a construction working face in the main tunnel, the temporary air door facing the construction direction of the main tunnel remains open; otherwise, the temporary air door remains closed. Among the interlocking air doors, at least one air door remains closed.

[0038] The jet fan on the construction side is turned on for directional drainage of sewage.

[0039] Compared with the prior art, the above one or more technical solutions have the following beneficial effects:

[0040] 1. When designing the roadway construction ventilation plan, special consideration should be given to how to avoid the problem of "wind network short - circuit" caused by the coincidence of the movement path of polluted air and the path of fresh air introduction. This invention patent determines the working area structure through modeling, and sets the types and positions of air doors and air walls in the ventilation system, as well as the direction of the air duct according to the migration law of characteristic pollutants. It adopts layout schemes such as setting rigid air walls in the ventilation ducts and cross - passages of the auxiliary shaft yard without the need for unmanned vehicle passage, and setting air door devices in the exit roadway and cross - passages of the auxiliary shaft yard with the need for manned vehicle passage, etc., to optimize the air flow organization of roadway ventilation under different construction scenarios in the ultra - deep shaft working area, improve the ventilation control effect of pollutants and inhibit the back - flow movement of polluted air, fundamentally solve the "wind network short - circuit" problem, and optimize the air flow organization situation and pollutant discharge effect.

[0041] 2. When conducting unidirectional or bidirectional asymmetric multi - working - face construction ventilation, due to the asymmetric air pressure distribution in the roadway of the underground working area, it often drives the polluted air to move in a direction deviating from the exhaust vertical shaft (such as Figure 1 the main shaft in the example), or move around multiple circular areas formed by the parallel adit roadway - cross - passage - main tunnel roadway - cross - passage, main shaft yard - parallel adit roadway, resulting in the long - term retention of polluted air in the underground working area, which extremely affects the sewage discharge efficiency. This invention patent comprehensively considers the differences in scenarios such as the large - mileage direction, small - mileage direction, main tunnel construction, and parallel adit construction according to different asymmetric multi - working - face construction scenarios, opens or closes the corresponding air doors and fans, better controls and guides the polluted air to move and be discharged into the roadway with less impact, optimizes the air flow organization of roadway ventilation under different construction scenarios in the ultra - deep shaft working area, and improves the sewage discharge efficiency in the underground working area. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The schematic drawings of the specification forming a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0043] Figure 1 is a simplified schematic diagram of the plane layout of the underground working area of a certain ultra - deep tunnel shaft provided by the present invention;

[0044] Figure 2 is a schematic diagram of the overall structure of the geometric model of the ultra - deep shaft working area arranged with double shafts provided by the present invention;

[0045] Figure 3 is a schematic diagram of the partial structure of the geometric model of the ultra - deep shaft working area arranged with double shafts provided by the present invention;

[0046] Figure 4 is a schematic diagram of the layout of ventilation test points in the underground working area of the ultra - deep shaft provided by the present invention;

[0047] Figure 5It is a schematic diagram of the geometric model when setting air doors in the work area provided by the present invention;

[0048] Figure 6 It is a schematic plan view of the layout of the ventilation system in the work area provided by the present invention;

[0049] Figure 7 It is a schematic diagram of the structure of the ventilation duct in the work area provided by the present invention;

[0050] Figure 8 It is a schematic plan view of the opening condition of the ventilation system during the construction of two-way four working faces in the work area provided by the present invention;

[0051] Figure 9 It is a schematic plan view of the opening condition of the ventilation system during the construction of two-way two working faces in the work area provided by the present invention;

[0052] Figure 10 It is a schematic plan view of the opening condition of the ventilation system during the construction of two-way three working faces in the work area provided by the present invention;

[0053] Figure 11 It is a schematic plan view of the opening condition of the ventilation system during the construction of one-way two working faces in the work area provided by the present invention. Detailed implementation manners

[0054] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0055] It should be noted that the following detailed description is exemplary and is intended to provide further illustration of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0056] Term explanation:

[0057] Extra-long railway tunnel refers to a railway tunnel with a length of more than 10,000 meters.

[0058] Ultra-deep shaft: In the "Safety Technical Code for Ultra-deep Shaft Construction", the depth of the ultra-deep shaft is specified to exceed 1200m, but this code is for the mining field. This solution is for the shaft in railway tunnel construction, and there is no clear code requirement in the industry. According to the experience of most engineering cases, shafts with a depth of 500 meters usually face technical challenges such as high temperature, high pressure, complex geological conditions and construction costs. Therefore, in this embodiment, shafts with a depth of more than 500 meters are considered ultra-deep shafts.

[0059] Large mileage direction refers to the end direction of the tunnel line, that is, the direction of the tunnel exit.

[0060] Small mileage direction refers to the starting direction of the tunnel line, that is, the direction of the tunnel entrance.

[0061] A construction ventilation method for multiple working faces in an ultra-deep shaft section of an extra-long railway tunnel, comprising the following steps:

[0062] Establish a model based on the section parameters, conduct a simulation of the transport of characteristic pollutants under the set boundary conditions, and determine the layout structure of the ventilation system in the section according to the simulation results;

[0063] The layout structure of the ventilation system includes:

[0064] An axial flow fan group is arranged in a large-section ventilation duct connected to the parallel heading or the main tunnel. The ventilation duct is located between the auxiliary shaft and the auxiliary shaft yard, and is used to introduce fresh air from the auxiliary shaft and send it into the air duct; there are at least two jet fans, which are respectively arranged in the two transportation tunnels of the main shaft yard, and are used to accelerate the polluted air and discharge it through the main shaft;

[0065] The air duct is led out by the axial flow fan group and laid along the wall of the main tunnel. After passing through the rigid air wall, it is laid along the wall of the parallel heading in the directions towards the small mileage and the large mileage respectively. The main tunnel and the parallel heading are arranged side by side;

[0066] The rigid air wall is arranged in the ventilation duct and the two cross passages closest to the ventilation duct; the temporary air doors are arranged in the two cross passages that are the second closest to the ventilation duct; the interlocking air doors are arranged in the two transportation tunnels of the auxiliary shaft yard. The interlocking air doors include a normally open air door and a normally closed air door that are interlocked, and at least one of the two air doors remains closed.

[0067] Establish a model based on the section parameters. In this embodiment, taking an ultra-deep shaft section of a tunnel with a depth exceeding 600m as an example, establish a CFD calculation model for roadway construction ventilation in the ultra-deep shaft. By analyzing the law of pollutant migration in roadway ventilation in the ultra-deep shaft section, determine the influence of the shaft depth on the air flow distribution characteristics and pollution discharge efficiency in the shaft underground section arranged with double shafts under different roadway ventilation schemes, and finally determine the ventilation scheme during construction.

[0068] The plane layout structure of an ultra-deep shaft section of a tunnel with a depth exceeding 600m is as Figure 1As shown in the figure, the work area has a main tunnel and a parallel adit (parallel pilot tunnel) arranged in parallel. There are multiple groups of cross tunnels between the main tunnel and the parallel adit. The vertical shaft is set with a main shaft and an auxiliary shaft. The main shaft is located 60 m on one side of the center line of the main tunnel, and the shaft diameter is 6 m. The auxiliary shaft is located 30 m on the other side of the center line of the main tunnel, and the inner diameter of the shaft is 5 m. There are transportation tunnels respectively facing the large mileage and small mileage directions between the bottom end of the main shaft and the parallel adit. A corresponding slag transfer yard is set in each group of transportation tunnels (in this embodiment, the slag transfer yard facing the small mileage direction is the No. 1 slag transfer yard, and the slag transfer yard facing the large mileage direction is the No. 2 slag transfer yard). The transportation tunnels in both directions and the parallel adit form a circular yard. There are transportation tunnels respectively facing the large mileage and small mileage directions between the bottom end of the auxiliary shaft and the main tunnel. There is also a ventilation duct between the two groups of transportation tunnels. The transportation tunnels in both directions and the main tunnel form a circular yard. The working faces in both the large mileage and small mileage directions of the work area are excavated by the drill and blast method.

[0069] Considering that both the main and auxiliary vertical shafts need to be used as construction production channels for introducing fresh air, transporting materials, personnel entry and exit or transferring slag, rather than only being used as ventilation shafts. If the forced ventilation is adopted, it is not only restricted by the limit distance of single-heading ventilation, but also the layout of air ducts along the auxiliary shaft will greatly affect the lifting operation capacity of the auxiliary shaft. Therefore, in this embodiment, the roadway ventilation method is adopted. The fresh air enters the entire work area from the auxiliary shaft, and the polluted air is discharged from the main shaft. Axial flow fans are arranged at the ventilation duct area of the auxiliary shaft yard, and flexible air ducts are matched to supply air to the working faces in both the large mileage and small mileage directions. Except for the necessary passage for construction personnel and vehicle evacuation liaison channels (such as Figure 1 the L2# cross tunnel and the L5# cross tunnel) and the newly added cross tunnels, hard air walls are set to block the air flow after the other cross tunnels complete the penetration tasks of the corresponding adjacent main tunnel sections.

[0070] The ANSYS SpaceClaim software is used to establish the geometric model of the work area. As Figures 2 - 3 shown, the lengths of the driving tunnels in both the large mileage and small mileage directions of the main tunnel are both set to 100 m, and the lengths of the driving tunnels in both the large mileage and small mileage directions of the parallel adit are both set to 130 m to meet the requirement that the working face of the driving tunnel in the parallel adit needs to be at least 30 m ahead of the driving working face in the same direction of the main tunnel. The axial flow fans in the model are simplified as cylinders and meshed.

[0071] Solution parameter settings. The ventilation calculation model uses a pressure-based transient solver and selects the SIMPLE algorithm to solve the pressure coupling equations. The Realizable k-ε two-equation model is used as the turbulence model. The gravity effect is turned on, and the numerical value in the Z direction is set to -9.8 m / s 2 .

[0072] Simulation of characteristic pollutant transportation. CO in the fumes generated by the blasting of the working face is selected as the characteristic pollutant in the shaft work area, and the law of pollutant migration during the roadway ventilation in the underground work area is analyzed by the change of CO concentration at different ventilation times after blasting. The component transportation model is turned on, and a total of two components, air and carbon monoxide (CO), are set. Both components of gas are regarded as incompressible ideal gases. After the blasting of each working face, the throwing distance L of the fumes and the initial concentration c of CO in the space where the fumes are thrown are 0 Calculated respectively by the following formulas.

[0073]

[0074] In the formula, m G is the amount of explosive used for a single blasting, kg; b is the amount of harmful gas (converted to CO) generated by 1 kg of explosive, m 3 / kg. Usually, according to experience, b = 0.04 m 3 / kg; S is the cross-sectional area of the tunnel excavation, m 2 , and according to the actual project, S = 50.7 m 2 .

[0075] The surrounding rock conditions in the construction section of the relying project are complex. The full-face excavation or bench method excavation method needs to be adopted according to different surrounding rock conditions. In this embodiment, the average single-blasting excavation distance of the tunneling working face is 1.5 m, and the specific charge ratio is 1.1 kg / m 3 . Taking this as an example, through calculation, it is obtained that the average amount of explosive used for a single blasting in the tunneling working face of the relying project m G is 83.7 kg, the throwing distance L of the fumes after blasting is 31.7 m, and the initial concentration of CO in the space where the fumes are thrown is 2110 mg / m 3 , which is converted to a mass fraction of 1.633×10 -3 . According to the requirement in the current specification that the allowable concentration of CO in the tunnel shall not be greater than 30 mg / m 3 , the qualified mass fraction of CO in the space of the underground work area of the ultra-deep shaft is converted to 2.32×10 -5 .

[0076] Boundary condition setting. The auxiliary shaft wellhead is selected as the inlet boundary of the model, and the main shaft wellhead is selected as the outlet boundary of the model. In actual projects, the main and auxiliary shaft wellheads are connected to the external environment. Since the main and auxiliary shaft wellheads are in the same ground work area, the height difference and temperature difference between the main and auxiliary shaft wellheads can be basically ignored. Before the shaft work area is connected with the adjacent work area, it is difficult to form a stable, continuous and effective natural ventilation wind flow in the shaft and the underground work area. The wind flow in the underground work area is only driven by the forced ventilation of mechanical ventilation equipment. Therefore, the main and auxiliary shaft wellheads are set as pressure outlet boundary conditions and pressure inlet boundary conditions respectively. The "operating pressure" of the numerical model is set to the theoretical atmospheric pressure of 80267Pa based on the elevation of the main and auxiliary shaft wellheads of the project (i.e. 1900.25m), and then the gauge pressure reference value in the wellhead pressure boundary condition is set to 0. The "operating density" value in the simulation is set to 0.

[0077] The momentum source term method is used to simulate the ventilation function of the axial flow fan. Assuming that an axial flow fan matches the parallel air duct to supply air to two working surfaces, the theoretical ventilation air volume of the axial flow fan can reach up to 3991m 3 / min. The axial force per unit volume of the axial flow fan S is converted by the following formula a 148.5N / m 3 .

[0078]

[0079] In the formula, S a is the axial force per unit volume, N / m 3 ; v is the wind speed when a given axial flow passes through the ventilation fan, m / s; ρ is the air density, kg / m 3 ; l is the length of the ventilation fan, m.

[0080] All walls are defined as non-slip solid walls ignoring the thermal boundary of the wall, and the standard wall function method is used. The roughness height is not set for the axial flow fan and ventilation duct wall, and the roughness height of the shaft wall, tunnel vault, two sides and bottom plate, and hard wind wall is set to 0.09m.

[0081] Numerical model verification. Ventilation field tests were conducted to obtain the data required for simulation. The test scenario was the ventilation scene during the rock drilling construction process in the small mileage direction of the flat guide section during the abnormal construction period. During the test, an underground axial flow fan was used to supply air to the intersection area of ​​the large mileage direction of the circular parking lot. At the same time, a temporary local fan was arranged in the communication channel, and a temporary ventilation duct with a diameter of 0.8m was connected to supply air to the working face of the test tunnel. The temporary duct was 25m away from the working face. The on-site ventilation wind speed test set up 20 test sections, and the measurement points were arranged as follows Figure 4As shown, a verification model is established according to the actual on-site measurement scenario. The ventilation momentum of the temporary local fan, combined with the average wind speed of 12.8 m / s at the air outlet of the temporary ventilation air duct obtained from on-site measurement, is set to 167 N / m after debugging 3 , so as to ensure the consistency of the initial conditions of the air flow at the air outlet of the air duct in the test roadway in the numerical model of the test scenario as much as possible. The initial space temperature, combined with the temperature of the fresh air introduced from the outside and the average temperature of the driving roadway measured on-site, is set to 25 °C.

[0082] By comparing the simulation results of the verification model with the measured results, there is a complex mixed flow state in the area between the vicinity of the air duct outlet and the driving face. The flow velocity varies greatly among the measuring points on the same measuring line. The simulation values are basically slightly higher than the measured values, and the change trends of the two are basically the same. The results of the left and middle measuring lines have a good correlation, but there are large errors in the results of the right measuring line, and the error range is within 0.5 m / s. The error situation of the right measuring line is mainly due to the ideal simplification of the spatial structure and layout of the construction machinery and equipment near the working face in the model and the neglect of the air leakage effect of the flexible air duct on-site. Therefore, there is a certain difference between the actual ventilation conditions measured on-site and the ideal ventilation conditions of the test scenario model. After the air flow develops to 40 m away from the working face, the wind speed is relatively stable, and it basically shows that the measuring points on the middle measuring line > the measuring points on the right measuring line > the measuring points on the left measuring line. The error between the simulation value and the measured value is small, and the correlation between the two is good. Generally speaking, the simulation results of the test scenario model are in good agreement with the variation law of the on-site ventilation air flow in the underground working area of the ultra-deep shaft. The turbulent mathematical model selected for the ventilation calculation model is reliable, the boundary conditions are set reasonably, and the numerical simulation results can better display the variation of the ventilation flow field in the ultra-deep shaft working area.

[0083] Combined with the results of model verification, the ventilation system layout shown in Figures 5 - 6 is adopted in this embodiment. Specifically, the structure of the working area is as follows:

[0084] There are multiple groups of cross passages between the main tunnel and the parallel pilot tunnel arranged in parallel. In this embodiment, they are set as L1#-L7# cross passages, where L1#, L6# and L7# are the cross passages to be constructed, and the existing cross passages are L2#-L5#.

[0085] The cross passages can also be divided according to the construction mileage direction. The cross passages along the small mileage direction with the ventilation duct as the boundary are X01, X02...Xn respectively, and the cross passages along the large mileage direction are D01, D02...Dn respectively. In this embodiment, the existing cross passages L2#-L5# are respectively named cross passage X02, cross passage X01, cross passage D01 and cross passage D02, and the to-be-constructed L6# cross passage is named cross passage D03;

[0086] The construction directions of the main tunnel and the pilot tunnel are bounded by the ventilation duct. One side is the small mileage direction, and the other side is the large mileage direction.

[0087] There are transportation roadways between the bottom end of the main shaft and the parallel adit, which are respectively oriented towards the large mileage and small mileage directions. In each group of transportation roadways, there is a corresponding slag transfer yard (in this embodiment, the slag transfer yard towards the small mileage direction is the No. 1 slag transfer yard, and the one towards the large mileage direction is the No. 2 slag transfer yard). The transportation roadways in both directions and the parallel adit form an annular main shaft yard, and the main shaft yard is connected to the main shaft.

[0088] There are transportation roadways between the bottom end of the auxiliary shaft and the main tunnel, which are respectively oriented towards the large mileage and small mileage directions. There is also a ventilation duct between the two groups of transportation roadways. The transportation roadways in both directions and the main tunnel form an annular auxiliary shaft yard, and the auxiliary shaft yard is connected to the auxiliary shaft.

[0089] Combined with the structure of the above-mentioned work area and the law of pollutant migration, the layout method of the ventilation system given in this embodiment is as follows:

[0090] The axial flow fan group is arranged in the ventilation duct for introducing fresh air from the auxiliary shaft and sending it into the air duct; there are at least two groups of jet fan groups, which are respectively arranged in the two transportation roadways of the main shaft yard for accelerating the discharge of polluted air into the main shaft.

[0091] After being led out by the axial flow fan group, the air duct is laid along the wall surface of the main tunnel towards the small mileage and large mileage directions respectively. After passing through the rigid air wall, it is laid along the wall surface of the parallel adit towards the small mileage and large mileage directions respectively.

[0092] There are three groups of rigid air walls, which are arranged in the ventilation duct and the two cross passages closest to the ventilation duct; there are two groups of temporary air doors, which are respectively arranged in the two cross passages that are the second closest to the ventilation duct; there are two groups of interlocking air doors, which are respectively arranged in the two transportation roadways of the auxiliary shaft yard. The interlocking air doors include a normally open air door and a normally closed air door that are interlocked. In each group of air doors, the air door closer to the main tunnel side is the normally closed air door, and the other air door is the normally open air door. At least one of the two air doors remains closed.

[0093] That is, the rigid air walls are arranged in cross passage X01, cross passage D01 and the ventilation duct, the temporary air doors are arranged in cross passage X02 and cross passage D02, and there are at least two groups of axial flow fans, which are respectively used to provide fresh air for the small mileage and large mileage directions.

[0094] The longitudinal structure of the auxiliary shaft is as Figure 7 shown. The bottom of the auxiliary shaft shaft is the underground headgate roadway, and the headgate roadway is connected to the shaft of the auxiliary shaft. The upper space of the headgate roadway is connected to the ventilation duct through an inclined shaft at a certain inclination angle. The cross-sectional diameter or width of the inclined part is smaller than that of the ventilation duct. In this embodiment, the ventilation duct of the inclined part is named the small-section ventilation duct, and the ventilation duct of the horizontal part is named the large-section ventilation duct. The axial flow fan is arranged in the large-section ventilation duct.

[0095] Considering the structure of the work area, the actual project considered the use of tunnel ventilation during normal construction. Therefore, in the early design and excavation period, an oblique channel was dug under the auxiliary shaft to connect to the tunnel flat guide or main tunnel (i.e. ventilation duct), and the axial flow fan was directly placed in the ventilation duct to draw air, so that the fresh air flow was introduced into the underground work area through the ventilation duct, which can avoid the noise and spatial structure occupation during the axial flow fan induction process. The impact on the original complex transportation construction process route arrangement under the auxiliary shaft. In addition, from the perspective of ventilation flow, placing an axial flow fan in the ventilation duct consumes less energy than placing an axial flow fan directly under the auxiliary shaft, which is more economical.

[0096] The air duct adopts PVC flexible double-resistance soft air duct, one end of which is connected to the air outlet of the axial flow fan, and the other end is extended through the construction tunnel to the excavation working face close to the main tunnel or horizontal guide in the direction of mileage, or a "Y" or "T" shaped parallel structure is used to connect the air duct branch at an appropriate position, and extend it to the working face close to the horizontal guide or main tunnel in the direction of mileage through the two side cross passages closest to the ventilation duct.

[0097] In this embodiment, the suitable position usually refers to the middle area between the air outlet side of the axial fan (i.e., the side of the air duct interface) and the connecting channel (cross channel) that needs to be accessible to people and vehicles in the large and small mileage directions; each section of the ventilation duct is connected by slot connection, bolt connection or flange connection according to the construction situation.

[0098] The hard wind wall is arranged at the large-section ventilation duct of the auxiliary shaft yard and in the middle of the transverse passage where vehicles and personnel do not need to pass after the corresponding adjacent main tunnel section is completed, namely transverse passage X01 and transverse passage D01. The hard wind wall arranged at the ventilation duct of the auxiliary shaft yard is penetrated by the axial flow fan, and the hard wind wall arranged in the middle of the two side connecting passages (transverse passage X01 and transverse passage D01) closest to the ventilation duct is penetrated by the ventilation duct; the hard wind wall is made of hard materials or rigid materials such as galvanized iron sheets; the hard wind wall and the ventilation duct are connected and sealed with hard flanges.

[0099] The linkage damper is a pressure-free damper, which consists of at least two dampers that can be controlled in linkage. The distance between the two dampers is about 5-10m. Only when one damper is closed can the other damper be opened. Each damper is based on the principle of pressure balance, and the two doors are opened and closed synchronously in different directions through a connecting rod structure and a limiter fixed on the door frame. The pressure-free damper can be fully automatically controlled by infrared sensing or semi-automatically controlled by buttons. Among them, in each group of dampers, the damper close to the excavation tunnel is a normally closed pressure-free damper, and the other damper is a normally open damper.

[0100] The temporary air door is installed in two transverse channels (i.e., transverse channel X02 and transverse channel D02) connecting the inlet and outlet of the main shaft yard and the auxiliary shaft yard in the large and small mileage directions. The temporary air door consists of at least one air door that is semi-automatically opened by a button. Each air door is based on the principle of pressure balance, and the two doors are opened and closed in opposite directions synchronously through a connecting rod structure and a limit fixed on the door frame. The temporary air door is arranged in the transverse channel for passing personnel and construction vehicles between the horizontal tunnel and the main tunnel; the temporary air door is normally in the open state, and mature air door products on the market can be selected.

[0101] The jet fan is installed near the entrance roadway of the main shaft yard (slag transfer yard), and is installed close to one side of the chamber wall according to the spatial structure of the main shaft yard (slag transfer yard).

[0102] The multi-face construction scenarios include two-way symmetric construction scenarios, two-way asymmetric construction scenarios, and one-way asymmetric construction scenarios.

[0103] The two-way symmetric construction scenario is a multi-face construction scenario where construction is carried out simultaneously on symmetric working faces in the large mileage or small mileage directions, including the two-way four-face construction scenario ( Figure 8 ) and the two-way two-face construction scenario ( Figure 9 ). The two-way asymmetric construction scenario is a construction scenario where construction is carried out simultaneously in the large and small mileage directions, but the construction working faces are not symmetric on the horizontal tunnel or main tunnel line, mainly the two-way three-face construction scenario. The one-way asymmetric construction scenario is a multi-face construction scenario where construction is carried out only on one side of the double working faces in the large mileage or small mileage directions, mainly the one-way double-face construction scenario.

[0104] The two-way symmetric multi-face construction scenario includes the two-way four-face construction scenario as Figure 8 shown, where tunnel boring construction is carried out simultaneously in the large and small mileage directions in the main tunnel and the horizontal tunnel; the two-way two-face construction scenario is as Figure 9 shown, which is a scenario where tunnel boring construction is carried out simultaneously in the large and small mileage directions in the main tunnel or the horizontal tunnel (in this embodiment, tunneling is carried out simultaneously in the large and small mileage directions in the horizontal tunnel). When two-way symmetric multi-face construction is carried out in the ultra-deep shaft section, two axial fans are started, and air is supplied to the working faces through the ventilation ducts. When two-way four-face construction is carried out, the temporary air doors on both sides of the connecting passage remain open. When two-way two-face construction is carried out, if there is a construction working face in the main tunnel, the temporary air door facing the construction direction of the main tunnel remains open, otherwise the temporary air door remains closed. The air door on the side close to the construction roadway in the non-pressure air doors at both exits of the auxiliary shaft yard remains closed, and the other air door is open.

[0105] When passing through the auxiliary shaft yard, when passing through the normally closed air door in the interlocking air door, first interlock to close the normally open air door, and then open the normally closed air door; after passing through the normally closed air door, control the normally closed air door to reset and close, and at the same time interlock to open the normally open air door.

[0106] There is no restriction on the direction of the linkage damper. For example, when construction personnel or vehicles in the auxiliary shaft parking lot need to temporarily pass into the construction tunnel, they first pass through the normally open pressureless damper, and then open the normally closed damper through the fully automatic infrared sensor or semi-automatic button between the two dampers. At the same time, the normally open damper is closed in linkage, and then they can enter the excavation tunnel through the normally closed damper; after the construction personnel or vehicles pass through the normally closed damper, they reset the pressureless damper through the fully automatic infrared sensor or semi-automatic button outside the normally closed damper, that is, close the normally closed damper, and the normally open damper is opened in linkage. The temporary damper is in the normally open state. The opposite working faces of the horizontal guide or the main tunnel should keep the excavation construction progress relatively consistent as much as possible and maintain a relatively balanced wind pressure. When the excavation construction progress of the opposite working faces is quite different, the jet fan (lower power state) at the entrance of the slag yard on the side with faster construction progress is turned on to properly divert and balance the wind flow and wind pressure.

[0107] The bidirectional asymmetric multi-working surface construction scenario is mainly a bidirectional three-working surface construction scenario. Figure 10 As shown, in the horizontal guide, excavation is carried out in the direction of large mileage and small mileage at the same time, and in the main tunnel, excavation is carried out in the direction of large mileage or small mileage. When bidirectional asymmetric multi-working face construction is carried out, the axial flow fan corresponding to the construction side is turned on (generally, the axial flow fan unit has at least two axial flow fans, which provide fresh air for the construction in the direction of large mileage and small mileage respectively. In special cases, there can be more axial flow fans. The specific number is not limited here, and it is only used as a setting method in most cases), and air is supplied to the working face through the ventilation duct. The temporary damper of the communication channel in the construction direction of the main tunnel remains open, and the temporary damper of the communication channel in the non-construction direction remains closed. The damper on the side close to the construction lane among the pressure-free dampers of the exit lanes on both sides of the auxiliary shaft parking lot remains closed, and the other damper is in an open state.

[0108] When passing through the auxiliary shaft parking lot, after passing through the normally closed damper in the linkage damper, the normally open damper is first linked to close, and then the normally closed damper is opened; after passing through the normally closed damper, the normally closed damper is controlled to reset and close, and the normally open damper is simultaneously linked to open. There is no restriction on the direction of passage. For example, when construction personnel or vehicles in the auxiliary shaft parking lot need to temporarily pass into the construction tunnel, they first pass through the normally open non-pressure damper, and then open the normally closed damper through the fully automatic infrared sensor or semi-automatic button between the two dampers. The normally open damper is linked to close, and then the normally closed damper can be passed through the normally closed damper to enter the excavation tunnel; after the construction personnel or vehicles pass through the normally closed damper, they finally reset the non-pressure damper through the fully automatic infrared sensor or semi-automatic button outside the normally closed damper, that is, close the normally closed damper, and the normally open damper is linked to open. Close the temporary damper of the communication channel on the construction side of the single working face through the control button, turn on the jet fan at the entrance of the slag yard on the construction side, and drain the sewage in a directional manner.

[0109] The one-way asymmetric multi-working surface construction scenario is mainly a one-way double-working surface construction scenario. Figure 11As shown in the figure, tunneling is carried out in the main tunnel and the parallel pilot tunnel in the direction of large mileage or small mileage. When the ultra-deep shaft work area conducts one-way asymmetric multi-face construction, the corresponding axial flow fan on the construction side is turned on, and air is supplied to the working face through the ventilation duct. The temporary air door in the connecting passage in the construction direction remains open, the temporary air door in the connecting passage in the non-construction direction remains closed, and the air door on the side close to the construction roadway in the non-pressure air doors at both exits of the auxiliary shaft yard remains closed, and the other air door is open.

[0110] When passing through the auxiliary shaft yard, passing through the normally closed air door in the interlocking air doors, first interlock to close the normally open air door, and then open the normally closed air door; after passing through the normally closed air door, control the normally closed air door to reset and close, and at the same time interlock to open the normally open air door. There is no restriction on the passing direction. For example, when construction personnel or vehicles in the auxiliary shaft yard need to temporarily pass into the construction roadway, first pass through the normally open non-pressure air door, and then use the fully automatic infrared induction or semi-automatic button between the two air doors to open the normally closed air door. The normally open air door is interlocked to close, and then the normally closed air door can be passed through to enter the driving roadway; after the construction personnel or vehicles pass through the normally closed air door, finally use the fully automatic infrared induction or semi-automatic button outside the normally closed air door to reset the non-pressure air door, that is, close the normally closed air door, and the normally open air door is interlocked to open. Close the temporary air door in the non-construction side connecting passage through the control button, and turn on the jet fan at the entrance of the slag transfer yard on the construction side to direct the drainage of sewage.

[0111] By setting non-pressure air doors with interlocking control at both exits of the auxiliary shaft yard, the circulation return path of the polluted air in the multi-face work area of the underground work area can be effectively blocked, the problem of short-circuit of the air network in the underground work area can be essentially inhibited, and the ventilation and sewage discharge efficiency in the underground work area can be improved.

[0112] In addition to the multi-face construction scenario introduced above, there is also a single-face construction scenario in the actual project. In the single-face construction scenario, the corresponding axial flow fan on the construction side is turned on, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation duct;

[0113] During construction, if there is a construction working face in the main tunnel, the temporary air door facing the construction direction of the main tunnel remains open, otherwise the temporary air door remains closed, and in the interlocking air doors, at least one air door remains closed:

[0114] The jet fan on the construction side is turned on to direct the drainage of sewage.

[0115] Furthermore, by setting and timely enabling the temporary air door and the jet fan, the problem of stagnant polluted air caused by uneven distribution of ventilation air pressure in the two-way and one-way asymmetric construction scenarios in the ultra-deep shaft work area can be optimized to a certain extent, thereby improving the ventilation and sewage discharge effect in the underground work area.

[0116] Different types of air doors can improve the ventilation effect in the work area by their set positions and by adopting different opening and closing states in different construction scenarios. Through relevant simulation experiments, when using the roadway ventilation scheme without air doors, some of the polluted air in the underground work area will flow back to the axial flow fan for recirculation and mix with the fresh air outside the well, resulting in "ventilation short - circuit", and the ventilation quality is poor. However, after setting air doors at the two - side exit roadways of the auxiliary shaft yard to cut off the recirculation path, the pollutant discharge efficiency in the underground work area is significantly improved.

[0117] Through relevant simulation experiments, when using the roadway ventilation scheme without air doors, as the depth of the vertical shaft increases, the inlet air flow rate of the underground axial flow fan basically remains unchanged. However, due to the increase in the frictional resistance along the shaft and the vertical static pressure difference, the proportion of fresh air flow outside the well decreases, while the proportion of polluted air flow in the underground gradually increases, and the pollutant discharge efficiency in the underground work area decreases.

[0118] Through relevant simulation experiments, when using the roadway ventilation scheme with air doors, as the depth of the vertical shaft increases, the flow rate of the underground axial flow fan decreases, the ventilation flow velocity in the underground work area decreases, and the pollutant discharge efficiency gradually decreases, but it is still higher than that without air doors.

[0119] Therefore, through the above - mentioned ventilation construction method, arrange the required fans, air ducts and air doors at specific positions in the underground work area of the ultra - deep vertical shaft, improve the roadway ventilation effect in the two - way and one - way multi - working - face construction scenarios in the underground work area of the ultra - deep vertical shaft, inhibit the movement of polluted air backflow, fundamentally solve the problem of "ventilation network short - circuit", optimize the ventilation air flow organization and pollutant discharge effect, and provide a reference for formulating the ventilation control strategy for multi - working - face construction sites in the underground work area of ultra - deep vertical shafts of extra - long railway tunnels and similar projects.

[0120] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A ventilation method for multi-working surface construction in ultra-deep shaft work area of ​​an extra-long railway tunnel, characterized by: The following steps are involved: Establish a model based on the parameters of the work area, simulate the transport of characteristic pollutants under the set boundary conditions, and determine the layout structure of the ventilation system in the work area based on the simulation results; According to different working surface construction scenarios, switch the corresponding damper switch in the ventilation system; The layout structure of the ventilation system includes: The axial flow fan unit is arranged in the ventilation duct, which is located between the auxiliary shaft and the auxiliary shaft yard; the jet fan is arranged in the transport lane of the main shaft yard; The air duct is led out from the axial flow fan unit and laid along the wall of the main tunnel. After passing through the hard wind wall, the air duct is laid along the wall of the flat guide towards the direction of small mileage and large mileage respectively. The main tunnel and the flat guide are arranged in parallel. The hard wind wall is arranged in the ventilation duct and the two horizontal passages closest to the ventilation duct; the temporary dampers are arranged in the two horizontal passages that are second closest to the ventilation duct; the interlocking dampers are respectively arranged in the two transport lanes of the auxiliary shaft yard, and each group of interlocking dampers includes two interlockingly controlled dampers. During the operation, at least one of the two dampers remains closed.

2. A ventilation method for multi-working surface construction in an ultra-deep shaft area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: According to different construction working face scenarios and actual traffic needs, switch the corresponding damper to open or close, enable the axial flow fan to introduce fresh air from the outside through the ventilation duct and the auxiliary shaft, and send the fresh air into the working face through the air duct. Open and close the jet fan according to actual conditions to drive the generated polluted air to be discharged through the main shaft.

3. A ventilation method for multi-working surface construction in an ultra-deep shaft area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: The model established according to the work area parameters includes the following steps: The main tunnel and the horizontal guide are arranged in parallel, and there are multiple sets of cross passages between the main tunnel and the horizontal guide. The cross passages along the direction of small mileage are X01, X02...Xn, and the cross passages along the direction of large mileage are D01, D02...Dn; There are transport lanes facing the long mileage and short mileage directions between the bottom of the main shaft and the horizontal guide. Each group of transport lanes is equipped with a corresponding slag transfer yard. The transport lanes in two directions and the horizontal guide form a circular main shaft yard, which is connected to the main shaft. There are transport tunnels facing the long mileage and short mileage directions respectively between the bottom of the auxiliary shaft and the main tunnel. There is also a ventilation duct between the two groups of transport tunnels. The transport tunnels in two directions and the main tunnel form a circular auxiliary shaft yard, which is connected to the auxiliary shaft.

4. A ventilation method for multi-working surface construction in an ultra-deep shaft area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: In each set of linked dampers, the damper close to the main tunnel is a normally closed damper, and the other damper is a normally open damper.

5. A ventilation method for multi-working surface construction in an ultra-deep shaft area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: The hard wind wall is made of hard material and is sealed to the wind duct. The hard wind wall is used to prevent gas from flowing through the channel from the space outside the wind duct.

6. A ventilation method for multi-working surface construction in an ultra-deep shaft area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: The multi-working face construction scenario includes a two-way four-working face construction scenario. In the two-way four-working face construction scenario, the axial flow fan unit is started, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation duct; During the construction period, the temporary dampers are kept open, and at least one damper in each set of linked dampers is kept closed; When the difference in excavation construction progress of the opposite working faces of the horizontal pilot or main tunnel exceeds the set range, the jet fan at the entrance of the slag dump on the side with faster construction progress is turned on to balance the wind flow and pressure by draining the polluted air.

7. A ventilation method for multi-working surface construction in an ultra-deep shaft area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: The multi-working face construction scenario includes a bidirectional dual-working face construction scenario. In the bidirectional dual-working face construction scenario, the axial flow fan unit is started, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation duct; During construction, if there is a construction working surface in the main tunnel, the temporary damper facing the main tunnel construction direction shall remain open, otherwise the temporary damper shall remain closed, and at least one damper in each group of linked dampers shall remain closed; When the difference in excavation construction progress of the opposite working faces of the horizontal pilot or main tunnel exceeds the set range, the jet fan at the entrance of the slag dump on the side with faster construction progress is turned on to balance the wind flow and pressure by draining the polluted air.

8. A ventilation method for multi-working surface construction in an ultra-deep shaft work area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: The multi-working face construction scenario also includes a two-way three-working face construction scenario. In the two-way three-working face construction scenario, the axial flow fan unit is started, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation duct; During construction, if there is a construction working surface in the main tunnel, the temporary damper facing the main tunnel construction direction shall remain open, otherwise the temporary damper shall remain closed, and at least one damper in each group of linked dampers shall remain closed; The jet fan on one side of the double working surface construction is turned on to drain sewage in a directional manner.

9. A ventilation method for multi-working surface construction in an ultra-deep shaft area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: The multi-working face construction scenario also includes a one-way double-working face construction scenario. In the one-way double-working face construction scenario, the axial flow fan corresponding to the construction side is turned on, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation duct; During the construction period, the temporary dampers in the construction direction are kept open, the temporary dampers in the non-construction direction are closed, and among the linked dampers, at least one damper is kept closed; The jet fan on one side of the double working surface construction is turned on to drain sewage in a directional manner.

10. A ventilation method for multi-working surface construction in an ultra-deep shaft work area of ​​an extra-long railway tunnel as claimed in claim 1, characterized in that: In addition to the multi-working face construction scenario, there is also a single-working face construction scenario. In the single-working face construction scenario, the axial flow fan corresponding to the construction side is turned on, and the fresh air from the auxiliary shaft is supplied to the working face through the ventilation duct; During construction, if there is a construction working surface in the main tunnel, the temporary damper facing the main tunnel construction direction remains open, otherwise the temporary damper remains closed, and among the linkage dampers, at least one damper remains closed: The jet fan on the construction side is turned on to drain sewage in a directional manner.

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