A two-stage ventilation structure and ventilation method for adjacent construction section tunnels

Abstract

The present invention discloses a two-stage ventilation structure and ventilation method of adjacent construction section tunnels, including a main tunnel and a branch tunnel; the main tunnel is divided into two adjacent first construction sections and a second construction section; the branch tunnel is the entrance to the second construction section. The two-stage ventilation method of adjacent construction section tunnels of the present invention makes full use of the on-site conditions of the branch tunnel and the adjacent construction section. When the construction distance of the second construction section is short, the two adjacent construction sections adopt independent push-in ventilation. When the ventilation distance of the second construction section is long, the first construction section and the branch tunnel that have been connected are used to adopt relay-type laneway joint ventilation, and the ventilation method is flexible and changeable; independent push-in ventilation ensures the ventilation effect in the early stage, and relay-type laneway joint ventilation ensures the ventilation effect in the later stage. The two-stage ventilation has good ventilation effect, which ensures the safety of construction personnel and equipment; the main fan and wind duct of the first construction section can be transferred to the second construction section, respectively used as relay fan and follow-up wind duct, which greatly reduces the cost.

Description

Technical Field

[0001] The invention relates to a two-stage ventilation structure and a ventilation method for adjacent construction section tunnels, belonging to the technical field of tunnel construction. Background Art

[0002] With the continuous development of underground engineering, there are more and more long and large tunnels, such as highway, railway, water conservancy and other tunnel projects. Due to the influence of geological, environmental, economic and other factors, the setting of branch tunnels in long and large tunnels is limited, resulting in excessively long ventilation distances in some tunnels. During tunnel excavation, as the excavation working face moves forward, the ventilation distance becomes longer and longer, and the ventilation difficulty becomes greater and greater.

[0003] At present, single-head pressure ventilation is commonly used for tunnel ventilation. In long and large tunnels, the ventilation distance is limited, and the requirements for ventilation equipment such as fans and air ducts are too high. In addition, the ventilation effect in the later stage is poor, making it difficult to ensure the air quality and personnel safety in the tunnel. Summary of the invention

[0004] The invention provides a two-stage ventilation structure of adjacent construction section tunnels and a ventilation method thereof.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A two-stage ventilation structure for adjacent construction section tunnels, comprising a main tunnel and a branch tunnel; the main tunnel is divided into two adjacent first and second construction sections; the branch tunnel is the entrance to the second construction section; the first construction section is constructed from the entrance to the branch tunnel and then constructed in the direction of the second construction section; the second construction section is constructed from the branch tunnel into the main tunnel in a direction away from the first construction section, and tunnel ventilation is divided into two stages, in the first stage, the first construction section and the second construction section are constructed simultaneously until the first construction section is connected; in the second stage, the first construction section is connected to the second construction section.

[0007] Preferably, the first construction section is shorter, i.e., 5-10 km, and the second construction section is longer, i.e., 10-30 km, and the first construction section is half the length of the second construction section.

[0008] A ventilation method for a two-stage ventilation structure of adjacent construction section tunnels, comprising the following steps:

[0009] S1. In the first stage, the two adjacent first construction sections and second construction sections are ventilated independently, and both adopt forced ventilation. A main fan is set at the entrance of the first construction section, and a wind tube is set on the main fan. The air enters from the entrance of the first construction section and returns to the original route after reaching the first construction section's face. A main fan is set at the entrance of the branch tunnel of the second construction section. The air enters from the branch tunnel and returns to the original route after reaching the second construction section's face.

[0010] S2. The second stage adopts relay-type tunnel joint ventilation; fresh air is supplied by the main fan at the entrance of the branch tunnel of the second construction section, enters the main tunnel through the branch tunnel, and a relay fan is set at a certain distance from the main tunnel to deliver the fresh air to the second construction section's heading face (14) and then return the fresh air from the first construction section.

[0011] Preferably, both the main fan and the relay fan are axial flow fans.

[0012] Preferably, in the second stage, the main fan of the first construction section is moved to the second construction section as a relay fan, and the wind duct of the first construction section can be used as the follow-up wind duct of the second construction section.

[0013] Preferably, a shielding damper is provided at the end of the branch tunnel where the branch tunnel meets the main tunnel to isolate the branch tunnel.

[0014] Preferably, the size of the shielding damper is the same as the cross-section of the branch tunnel into the tunnel, and a movable door for the locomotive to pass through is provided below the shielding damper.

[0015] Compared with the prior art, the two-stage ventilation method of adjacent construction section tunnels of the present invention makes full use of the on-site conditions of the branch tunnel and the adjacent construction section. When the construction distance of the second construction section is shorter, the two adjacent construction sections adopt independent push-in ventilation. When the ventilation distance of the second construction section is longer, the first construction section and the branch tunnel that have been connected are utilized to adopt relay-type tunnel joint ventilation, and the ventilation mode is flexible and changeable; independent push-in ventilation ensures the early ventilation effect, and relay-type tunnel joint ventilation ensures the later ventilation effect. The two-stage ventilation has good ventilation effect, which ensures the safety of construction personnel and equipment; the main fan and wind duct of the first construction section can be transferred to the second construction section, respectively used as relay fan and follow-up wind duct, which greatly reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional view of the first stage ventilation of the two-stage ventilation structure of adjacent construction section tunnels of the present invention.

[0017] Figure 2 It is a cross-sectional view of the second stage ventilation of the two-stage ventilation structure of adjacent construction section tunnels of the present invention. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below with reference to the accompanying drawings.

[0019] like Figure 1 to Figure 2 As shown, a two-stage ventilation structure of adjacent construction section tunnels includes a main tunnel 1, a branch tunnel 2, a fan and a shielding damper 4; the main tunnel 1 is divided into two adjacent first construction sections 11 and a second construction section 12; the branch tunnel 2 is the entrance to the second construction section 12; the fan includes a main fan 31 and a relay fan 32.

[0020] The first construction section 11 is constructed from the entrance to the branch tunnel 2 and is constructed in the direction of the second construction section 12 ; the second construction section 12 enters the main tunnel 1 from the branch tunnel 2 and is constructed in the direction away from the first construction section 11 .

[0021] Tunnel ventilation is divided into two stages. In the first stage, the first construction section 11 and the second construction section 12 are constructed simultaneously until the first construction section 11 is connected; in the second stage 13, the first construction section 11 is connected to the second construction section 12.

[0022] The division of the first construction section 11 and the second construction section 12 is flexibly designed according to the tunnel design, hydrogeological conditions, construction method, branch tunnel 2 arrangement conditions and functions, etc. The first construction section 11 is shorter at 5-10km, and the second construction section 12 is longer at 10-30km. The first construction section 11 is about half the length of the second construction section 12.

[0023] In the first stage, the two adjacent first construction sections 11 and second construction sections 12 are ventilated independently, and both adopt forced ventilation; a main fan 31 is set at the entrance of the first construction section 11, and a wind tube 311 is set on the main fan 31. The air is taken in from the entrance of the first construction section 11 to the face 14 of the first construction section 11 and then returned along the original route; the main fan 31 is set at the entrance of the branch tunnel 2 of the second construction section 12, and the air is taken in from the branch tunnel 2 to the face 14 of the second construction section 12 and then returned along the original route.

[0024] The second stage 13 adopts relay-type tunnel joint ventilation; fresh air is supplied by the main fan 31 at the entrance of the branch tunnel 2 of the second construction section 12, enters the main tunnel 1 through the branch tunnel 2, and a relay fan 32 is set at a certain distance from the main tunnel 1 to deliver the fresh air to the heading face 14 of the second construction section 12 and then return the air from the first construction section 11.

[0025] In the second stage 13, due to the long ventilation distance, the main fan 31 of the first construction section 11 is moved to the second construction section 12 as the relay fan 32, and a relay fan 32 is added based on the actual ventilation distance and the fan equipment conditions. The wind duct 311 of the first construction section 11 can be used as the follow-up wind duct of the second construction section 12.

[0026] Both the main fan 31 and the relay fan 32 are axial flow fans;

[0027] The selection of the fan is based on comprehensive consideration of factors such as the required air volume of the tunnel face 14, ventilation distance, air leakage rate, wind resistance, etc. The parameters of the upper-level fan are calculated based on the required air volume of the tunnel face 14, and the calculation is performed step by step until the main fan 31 at the tunnel entrance;

[0028] In the second stage 13, in order to ensure the ventilation effect, a shielding damper 4 is set at the end of the branch hole 2 where the branch hole 2 and the main hole 1 meet to isolate the branch hole 2 and prevent the return air from flowing through the branch hole 2;

[0029] The size of the shielding damper 4 is the same as the cross-section of the branch tunnel 2. A movable door for the locomotive to pass through is arranged below the shielding damper 4 to ensure smooth transportation channel.

[0030] The two-stage ventilation method of adjacent construction section tunnels of the present invention divides tunnel ventilation into two stages. During the short-distance construction period, adjacent construction sections are ventilated independently and pressure ventilation is adopted. When the distance is long, the adjacent construction sections are combined into one and relay-type tunnel joint ventilation is adopted to make the ventilation return air channel unobstructed and ensure the ventilation effect.

[0031] The two-stage ventilation method of adjacent construction section tunnels of the present invention fully utilizes the on-site conditions of the branch tunnel 2 and the adjacent construction sections. When the construction distance of the second construction section 12 is short, the two adjacent construction sections adopt independent push-in ventilation. When the ventilation distance of the second construction section 12 is long, the first construction section 11 and the branch tunnel 2 that have been connected are utilized to adopt relay-type tunnel joint ventilation, and the ventilation mode is flexible and changeable; independent push-in ventilation ensures the early ventilation effect, and relay-type tunnel joint ventilation ensures the later ventilation effect. The two-stage ventilation has good ventilation effect, which ensures the safety of construction personnel and equipment; the main fan 31 and the wind duct 311 of the first construction section 11 can be transferred to the second construction section 12, respectively used as the relay fan 32 and the follow-up wind duct, which greatly reduces the cost.

[0032] Finally, it should be noted that the above embodiments only illustrate the technical solutions of the present invention, rather than limiting it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ventilation method for a two-stage ventilation structure of a tunnel with adjacent construction sections, wherein the two-stage ventilation structure for realizing the ventilation method comprises a main tunnel (1) and a branch tunnel (2); the main tunnel (1) is divided into two adjacent first construction sections (11) and second construction sections (12); the branch tunnel (2) is an entrance to the second construction section (12); the first construction section (11) is constructed from the entrance to the branch tunnel (2) and then constructed in the direction of the second construction section (12); the second construction section (12) is constructed from the branch tunnel (2) into the main tunnel (1) and in the direction away from the first construction section (11); tunnel ventilation is divided into two stages: in the first stage, the first construction section (11) and the second construction section (12) are constructed simultaneously until the first construction section (11) is connected; in the second stage (13), the connection is made from the first construction section (11) to the second construction section (12); and the ventilation is characterized in that: The following steps are involved: S1, in the first stage, the two adjacent first construction sections (11) and second construction sections (12) are ventilated independently, and both adopt forced ventilation. A main fan (31) is arranged at the opening of the first construction section (11), and a wind tube (311) is arranged on the main fan (31). Air is taken in from the entrance of the first construction section (11) to the face (14) of the first construction section (11) and then returned along the original route. A main fan (31) is arranged at the entrance of the branch tunnel (2) of the second construction section (12). Air is taken in from the branch tunnel (2) to the face (14) of the second construction section (12) and then returned along the original route. S2, the second stage (13) adopts relay-type tunnel joint ventilation; fresh air is supplied by the main fan (31) at the entrance of the branch tunnel (2) of the second construction section (12), enters the main tunnel (1) through the branch tunnel (2), and a relay fan (32) is set at a certain distance from the main tunnel (1) to deliver the fresh air to the tunnel face (14) of the second construction section (12) and then return the fresh air from the first construction section (11); The first construction section (11) has a distance of 5-10 km, the second construction section (12) has a distance of 10-30 km, and the first construction section (11) is half the length of the second construction section (12); In the second stage (13), the main fan (31) of the first construction section (11) is moved to the second construction section (12) to serve as a relay fan (32), and the wind tube (311) of the first construction section (11) is used as a relay wind tube of the second construction section (12); In the second stage, a shielding damper (4) is provided at the end of the branch hole (2) at the junction of the branch hole (2) and the main hole (1) to isolate the branch hole (2).

2. The ventilation method of the two-stage ventilation structure of adjacent construction section tunnels according to claim 1 is characterized in that: The shielding damper (4) has the same size as the cross section of the tunnel entrance branch (2), and a movable door is provided below the shielding damper (4) for the locomotive to pass through.

3. The ventilation method of the two-stage ventilation structure of adjacent construction section tunnels according to claim 1 is characterized in that: The main fan (31) and the relay fan (32) are both axial flow fans.

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