A large-section tunnel cantilever type tunneling machine construction method ventilation dust removal system

Abstract

The application discloses a large-section tunnel cantilever type tunneling machine construction method ventilation and dust removal system. The tunnel hole is narrow, and construction dust cannot be removed quickly, and the hole environment is poor. The application comprises a full-section arched door frame arranged at the joint of a working face excavation area and a secondary lining construction area; an axial flow fan is arranged on the top of the arched door frame and connected with a dirty air ventilation air belt, and the other end of the dirty air ventilation air belt is arranged outside the hole; a jet flow fan is arranged at the hole position and connected with a fresh air ventilation air belt, and the other end of the fresh air ventilation air belt is arranged at the working face excavation area; a blocking facility is arranged on one side of the arched door frame. The application blocks the construction area by adopting the full-section door frame, discharges the dirty air in the working face construction area by arranging the axial flow fan above the door frame, provides fresh air into the hole by the jet flow fan at the hole, and forms an air circulation channel between the two, so that the dirty air can be discharged to the outside of the hole as soon as possible.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction technology, specifically relating to a ventilation and dust removal system for a large-section tunnel cantilever tunnel boring machine. Background Technology

[0002] With the continuous development of mechanized tunneling equipment in China, cantilever tunneling machines have gradually become an important piece of equipment in mechanized tunnel construction. Cantilever tunneling machines offer advantages such as flexibility, high reliability, and high excavation efficiency. They can remove soft rock around the tunnel, transport tunnel excavation waste, and move the equipment itself. Compared to drill-and-blast tunneling, cantilever tunneling machines have significant advantages and will be even more advantageous in future tunnel construction. However, the milling head of a cantilever tunneling machine generates a large amount of dust during the rock breaking process. Due to the long single-cycle excavation time, relatively small tunnel space, and poor air circulation, the construction dust cannot be quickly removed, resulting in a poor working environment inside the tunnel. This seriously affects the secondary lining and invert arch construction, impacts the overall construction efficiency of the tunnel during tunneling machine operation, worsens the working environment for construction personnel, and increases potential hazards to tunnel construction and operational safety.

[0003] Existing tunnel dust control facilities mainly improve the tunnel environment by installing automatic spraying devices inside the tunnel. However, the construction water will soften the surrounding rock inside the tunnel, affecting its stability. At the same time, it will also worsen the working conditions for construction workers inside the tunnel. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a ventilation and dust removal system for large-section tunnel cantilever tunnel boring machines. It uses ventilation to expel polluted air from the tunnel, replacing sprinkler systems, ensuring dryness inside the tunnel, avoiding the softening effect of construction water on the surrounding rock, achieving rapid removal of dust from the tunnel, ensuring a good construction environment inside the tunnel, and thus improving construction quality and efficiency.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A ventilation and dust removal system for a large-section tunnel cantilever tunnel boring machine is characterized by:

[0007] It includes a full-section arched portal frame, which is set at the junction of the excavation area and the secondary lining construction area at the working face;

[0008] An axial flow fan is installed on the top of the full-section arched portal frame. The axial flow fan is connected to a sludge ventilation duct, and the other end of the sludge ventilation duct is located outside the opening.

[0009] The jet flow fan is arranged at the hole opening position and connected with a fresh air ventilation air belt, and the other end of the fresh air ventilation air belt is arranged in the excavation area of the working face.

[0010] The full-face arch-shaped portal is provided with a blocking facility on one side of the working face.

[0011] Further, the dirty air ventilation air belt is provided with a circular framework at one end of the hole opening, the circular framework is provided with an arch-shaped fog supply pipe, and a plurality of spray heads are uniformly arranged on the arch-shaped fog supply pipe; and the arch-shaped fog supply pipe is connected with a water mist pump through a fog guide pipe.

[0012] Further, the radius of the outermost edge of the full-face arch-shaped portal is smaller than the clearance of the initial support by about 10-20 cm.

[0013] Further, two inclined braces are arranged above the three-jamb portal steel frame.

[0014] Further, the full-face arch-shaped portal comprises a full-face arch-shaped framework, the full-face arch-shaped framework is provided with a three-jamb portal steel frame, and longitudinal channel steels are arranged between adjacent three-jamb portal steel frames along the tunnel axis.

[0015] The full-face arch-shaped framework and the three-jamb portal steel frame are connected through horizontal steel supports and vertical steel supports.

[0016] Further, the blocking facility is arranged along the outer edge of the full-face arch-shaped framework and wrapped in a full-face manner, so as to separate the excavation area of the working face and the construction area of the secondary lining.

[0017] Further, the bottom of the full-face arch-shaped portal is connected with one end of a self-propelled inverted arch trestle through bolts.

[0018] The beneficial effects of the present application are as follows:

[0019] 1) The present application separates the construction area by adopting a full-face portal, at the same time, an axial flow fan is arranged above the portal to exhaust the dirty air in the working face construction area, a jet flow fan at the hole opening provides fresh air into the hole, and an air circulation channel is formed between the two, so that the dirty air in the working face can be quickly exhausted to the outside of the hole, ensuring the construction environment in the hole and protecting the life and property safety of the construction workers;

[0020] 2) The present application is provided with a full-face arch-shaped portal, which is wrapped in a full-circle along the outer edge of the portal, so as to separate the secondary lining construction section and the working face construction section, avoid the influence of the dust in the working face construction section on the secondary lining construction section, and simultaneously carry out the construction operation in the two areas, thereby improving the construction operation efficiency and ensuring the construction quality of the steel bar binding and waterproof board laying in the secondary lining construction section;

[0021] 3) The full-section arched gantry frame and the self-propelled inverted arch trestle of this invention are connected by bolts, which is convenient for disassembly during construction. After installation, it can move with the self-propelled inverted arch trestle, which is simple and practical.

[0022] 4) In order to avoid dust from being discharged from inside the cave to the outside and causing pollution to the environment outside the cave, the present invention sets a circular frame at the ventilation duct opening for discharging polluted air from inside the cave. An arched mist supply pipe is set at the upper semicircle of the frame. Several evenly spaced spray heads are installed on the mist supply pipe. When dust is discharged to the cave entrance, water mist is sprayed from the ventilation duct opening to suppress dust at the cave entrance and ensure the environment outside the cave. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of this application;

[0024] Figure 2 This is the AA cross-sectional view of this application;

[0025] Figure 3 This is a detailed drawing of Part A;

[0026] Figure 4 This is a detailed drawing of Part B;

[0027] In the diagram, 1-working face; 2-fresh air; 3-polluted air; 4-full-section arched portal frame; 5-full-section arched skeleton; 6-portal steel frame; 7-longitudinal channel steel; 8-bolt; 9-diagonal brace; 10-transverse steel support; 11-vertical steel support; 12-fresh air ventilation duct; 13-axial flow fan; 14-barrier facility; 15-polluted air ventilation duct; 16-jet fan; 17-circular skeleton; 18-mist supply pipe; 19-spray head; 20-mist induction pipe; 21-fine water mist pump; 22-water induction pipe; 23-self-propelled inverted arch trestle bridge. Detailed Implementation

[0028] The present invention will now be described in detail with reference to specific embodiments.

[0029] like Figure 1 As shown, the present invention includes a full-section arched portal frame 4, which is set at the junction of the excavation area of ​​the working face 1 and the secondary lining construction area.

[0030] like Figure 3 As shown, the bottom of the full-section arched gantry 4 is connected to one end of the self-propelled inverted arch trestle 23 by bolts 8. The full-section arched gantry 4 can move forward with the self-propelled inverted arch trestle 23. It is easy to disassemble during construction and is simple and practical.

[0031] The full-face arch-shaped portal 4 is provided with a blocking facility 14 on one side of the tunnel face 1, the blocking facility 14 is arranged along the outer edge of the full-face arch-shaped framework 5, adopts full-face wrapping, is used for separating the tunnel face excavation area and the secondary lining construction area, avoids the influence of the tunnel face construction dust on the secondary lining construction section, can simultaneously carry out the construction operation of the two areas, improves the construction operation efficiency, and guarantees the construction quality of the steel bar binding and the waterproof board laying of the secondary lining construction section.

[0032] As shown in Figure 2 The full-face arch-shaped portal 4 includes a full-face arch-shaped framework 5, three portal steel frames 6 are arranged in the full-face arch-shaped framework 5, longitudinal channel steels 7 are arranged between the adjacent three portal steel frames 6 along the tunnel axial direction and are welded into one body; the full-face arch-shaped framework 5 and the three portal steel frames 6 are connected through horizontal steel supports 10 and vertical steel supports 11; two inclined braces 9 are arranged above the three portal steel frames 6 to guarantee the stability of the portal;

[0033] The outermost edge steel frame of the full-face arch-shaped portal 4 is smaller than the initial support clearance by about 10-20 cm to guarantee the clearance requirement of the front and rear movement of the full-face portal; the three portal steel frames 6 provide a moving space for the slag car, do not need to be disassembled twice, and do not affect the tunnel tunnel face excavation and the secondary lining construction operation; the full-face arch-shaped portal 4 is pre-provided with a fresh air ventilation air belt 12 and a ventilation hole of an axial flow fan 13 to guarantee the installation requirement of the mechanical equipment.

[0034] The axial flow fan 13 is arranged at the top of the full-face arch-shaped portal 4, the axial flow fan 13 is connected with a dirty air ventilation air belt 15, the other end of the dirty air ventilation air belt 15 is arranged outside the hole; the axial flow fan 13 is used to discharge the dirty air 3 in the hole, the fan is closer to the tunnel face, can quickly discharge the dirty air of the tunnel face to the outside of the hole, adopts a ventilation mode to discharge the dirty air in the hole, replaces the spraying facility, guarantees the dryness of the hole, avoids the softening effect of the construction water on the surrounding rock of the hole, and guarantees the stability of the surrounding rock of the hole;

[0035] A jet flow fan 16 is arranged at the hole position, the jet flow fan 16 is connected with the fresh air ventilation air belt 12, the other end of the fresh air ventilation air belt 12 is arranged at the excavation area of the tunnel face 1; the jet flow fan 16 can connect the external fresh air 2 to the position of the tunnel face 1, guarantees the construction environment of the tunnel face; an air circulation channel is formed between the two ventilation air ducts.

[0036] As shown in Figure 4As shown, the dirty air ventilation wind belt 15 is provided with a circular framework 17 at one end of the hole opening, and an arch-shaped fog supply pipe 18 is arranged on the circular framework 17, and a plurality of spray heads 19 are uniformly arranged on the arch-shaped fog supply pipe 18; the arch-shaped fog supply pipe 18 is connected with a water mist pump 21 through a mist guide pipe 20; the water mist pump 21 is communicated with a water guide pipe 22, and the dust is discharged to the hole opening, and the water mist is sprayed at the wind belt opening to suppress the dust raising outside the hole and ensure the environment outside the hole.

[0037] The use method of the present application is as follows:

[0038] The full-section arch-shaped portal of the inverted arch trestle end is wrapped along the outer edge of the arch-shaped framework to block the excavation operation space of the working face, before the cantilevered tunneling machine excavates and constructs, the axial flow fan above the portal and the jet flow fan at the tunnel opening are started, the jet flow fan provides fresh air into the hole, the axial flow fan discharges the dirty air in the hole, and an air circulation channel is formed in the working face construction area to continuously supply fresh air to the area to ensure the construction environment of the working face. After stable air circulation is achieved, the cantilevered tunneling machine of the working face is started to excavate the working face. A large amount of dust in the hole will be generated near the working face. Because the working face construction area has formed a closed area, dust cannot escape to the secondary lining construction area, thereby avoiding the influence of dust on the secondary lining steel bar binding construction, waterproof board laying construction and the like. The secondary lining area can be normally constructed according to the construction organization arrangement, and the working face area can discharge a large amount of dust generated by the cantilevered tunneling machine to the outside of the hole through the axial flow fan.

[0039] The arch-shaped framework is arranged at the end of the dirty air ventilation wind belt, the arch-shaped fog supply pipe is arranged on the framework, and a plurality of uniformly spaced spray heads are arranged on the fog supply pipe. When the dust is discharged to the hole opening, the water mist is sprayed at the wind belt opening to suppress the dust raising at the hole opening and ensure the environment outside the tunnel hole.

[0040] When the tunnel hole is constructed for a certain distance, the self-propelled inverted arch trestle drives the full-section arch-shaped portal to move forward together, the ventilation wind belt is correspondingly lengthened, and the ventilation and dust removal needs of subsequent construction are ensured.

[0041] The content of the present application is not limited to the examples listed, and any equivalent transformation of the technical solution of the present application by a person skilled in the art by reading the specification of the present application is covered by the claims of the present application.

Claims

1. A method for ventilation and dust removal in large cross-section tunnel cantilever tunneling machine construction, characterized in that: before the excavation construction of the cantilever tunneling machine, the axial flow fan above the portal and the jet fan at the tunnel portal are started, the jet fan provides fresh air into the hole, the axial flow fan removes the dirty air in the hole, an air circulation channel is formed in the construction area of the working face to ensure the construction environment of the working face, after the stable air circulation is achieved, the cantilever tunneling machine at the working face is started to excavate the working face, a large amount of dust in the hole will be generated near the working face, because the construction area of the working face has formed a closed area, the dust cannot escape to the secondary lining construction area, the large amount of dust generated by the excavation of the cantilever tunneling machine in the working face area is discharged to the outside of the hole through the wind of the axial flow fan. The device used in the method is specifically: It comprises a full-face arch portal (4) arranged at the joint position of the excavation area of the working face (1) and the secondary lining construction area; An axial flow fan (13) is installed at the top of the full-face arch portal (4), the axial flow fan (13) is connected with a dirty air ventilation wind belt (15), and the other end of the dirty air ventilation wind belt (15) is arranged outside the hole; A jet fan (16) is arranged at the hole position, the jet fan (16) is connected with a fresh air ventilation wind belt (12), and the other end of the fresh air ventilation wind belt (12) is arranged in the excavation area of the working face (1); A blocking facility (14) is arranged on one side of the full-face arch portal (4) at the working face (1); The blocking facility (14) is arranged along the outer edge of the full-face arch skeleton (5) and wrapped in full-face to separate the excavation area of the working face and the secondary lining construction area; The bottom of the full-face arch portal (4) is connected with one end of the self-propelled inverted arch trestle (23) through bolts (8). A circular skeleton (17) is arranged at one end of the dirty air ventilation wind belt (15) at the hole, an arched mist supply pipe (18) is arranged on the circular skeleton (17), a plurality of spray heads (19) are uniformly arranged on the arched mist supply pipe (18), and the arched mist supply pipe (18) is connected with a water mist pump (21) through a mist guide pipe (20).

2. The method according to claim 1, characterized in that: The radius of the outermost steel frame of the full-face arch portal (4) is 10-20 cm smaller than the net clearance of the initial support.

3. The method according to claim 2, wherein the method is characterized by: 4.The method for ventilation and dust removal in large cross-section tunnel cantilever tunneling machine construction according to claim 3, characterized in that: The full-face arch portal (4) comprises a full-face arch skeleton (5), three portal steel frames (6) are arranged in the full-face arch skeleton (5), and longitudinal channel steels (7) are arranged between adjacent three portal steel frames (6) along the axial direction of the tunnel. The full-face arch skeleton (5) and the three portal steel frames (6) are connected through horizontal steel supports (10) and vertical steel supports (11). Two inclined braces (9) are arranged above the three portal steel frames (6).

5. The method according to claim 4, wherein the method is characterized by: ​

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