Y-shaped auxiliary tunnel and its construction method

Abstract

The present invention provides a Y-shaped auxiliary tunnel and a construction method thereof. The Y-shaped auxiliary tunnel comprises a left tunnel, a middle tunnel and a right tunnel. The middle tunnel is located between the left tunnel and the right tunnel, the left tunnel is located on the left side of the middle tunnel, and the right tunnel is located on the right side of the middle tunnel. The left tunnel, the middle tunnel and the right tunnel intersect to form a third intersection. In the third intersection, steel arch frames of the left tunnel, the middle tunnel and the right tunnel are connected with connection components in pairs. The connection components are located in the non-arch center area of ​​the third intersection. The connection components include at least one support rod. By adopting the above structure, the construction of tunnels of different sizes is divided, and the interference problem of the original construction traffic convergence point is reduced. The connection components form the steel arch frames at the third intersection into a connection structure, and form the initial support steel arch frames of the entire area of ​​the Y-shaped auxiliary tunnel into a whole, so that the auxiliary tunnel is safer and more reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and in particular to a Y-shaped auxiliary tunnel and a construction method thereof. Background Art

[0002] In the construction of long and large tunnels, auxiliary tunnels such as cross tunnels and inclined shafts are designed to divide the long tunnel into multiple sections, and then the main line construction is turned on after the auxiliary tunnel excavation construction, which can realize the excavation construction of different directions for different mileages, and effectively speed up the construction of long tunnels. The existing auxiliary tunnels are generally arranged in two ways: orthogonal and oblique.

[0003] See also Figure 1 and Figure 2 , Figure 1 and Figure 2 The auxiliary tunnels in the tunnel are arranged by oblique intersection, but Figure 1 and Figure 2 The auxiliary tunnels in the tunnel are inclined in different directions. When the auxiliary tunnels are arranged in an oblique intersection, the intersection of the main line and the auxiliary tunnel has an acute angle. Since the overall angle on the acute angle side is smaller, it will inevitably cause difficulties for construction machinery and vehicles on that side to turn, thereby causing traffic congestion. At the same time, the acute angle side will also affect the small angle bend of the ventilation duct in the later construction to produce wind resistance; therefore, no matter which direction the oblique construction is in, it will inevitably affect the main line construction.

[0004] See also Figure 3 , Figure 3 When the auxiliary tunnel in the orthogonal method is used, although the orthogonal method solves the influence of the small angle bend of the cross channel, it is affected by the interference of simultaneous construction of large and small mileages, and the vehicle traffic gathers in the auxiliary tunnel, which in turn affects the overall construction organization and is very likely to cause safety problems caused by the traffic in the area. An auxiliary tunnel that can reduce the interference of vehicle traffic gathering is now needed. Summary of the invention

[0005] The first object of the present invention is to provide a Y-shaped auxiliary tunnel that reduces the interference of vehicle traffic confluence.

[0006] The second object of the present invention is to provide a method for constructing the above-mentioned Y-shaped auxiliary tunnel.

[0007] In order to achieve the above-mentioned first purpose, the Y-shaped auxiliary tunnel provided by the present invention includes a left tunnel, a middle tunnel and a right tunnel, the middle tunnel is located between the left tunnel and the right tunnel, the left tunnel is located on the left side of the middle tunnel, the left tunnel and the middle tunnel are obliquely intersected, the right tunnel is located on the right side of the middle tunnel, and the right tunnel and the middle tunnel are obliquely intersected; the left tunnel is used to intersect with the tunnel main line to form a first intersection, the right tunnel is used to intersect with the tunnel main line to form a second intersection, and the left tunnel, the middle tunnel and the right tunnel intersect to form a third intersection; the left tunnel, the middle tunnel and the right tunnel are respectively provided with steel arch frames near the third intersection, and in the third intersection, the steel arch frames of the left tunnel, the steel arch frames of the middle tunnel and the steel arch frames of the right tunnel are connected with connecting components in pairs, the connecting components are located in the non-arch center area of ​​the third intersection, and the connecting components include at least one support rod.

[0008] It can be seen from the above scheme that the middle tunnel is extended in two directions to obtain the left tunnel and the right tunnel, wherein the left tunnel is obliquely intersected with the tunnel main line, and the left tunnel is used for construction in the direction of large tunnel mileage, while the right tunnel is obliquely intersected with the tunnel main line, and the right tunnel can be used for construction in the direction of small tunnel mileage, thereby dividing the construction of large and small tunnel mileages, reducing the interference problem at the original construction traffic gathering point, and the angle formed by the left tunnel and the construction direction of large tunnel mileage and the angle formed by the right tunnel and the construction direction of small tunnel mileage are both obtuse angles, which avoids the difficulty of turning for construction machinery and vehicles and avoids Small-angle bends in the ventilation ducts during the later construction caused wind resistance; when excavating the auxiliary tunnel, at the third intersection where the middle tunnel, the left tunnel and the right tunnel meet, the steel arch frames corresponding to the middle tunnel, the left tunnel and the right tunnel at the third intersection are connected to each other in pairs, and each connecting component is respectively arranged between two adjacent steel arch frames. The connecting components form the steel arch frames at the third intersection into a connecting structure, and form the initial supporting steel arch frames of the entire area of ​​the Y-shaped auxiliary tunnel into a whole, thereby reducing the problem of stress non-concentration in the special-shaped area, and the construction operation of the connecting structure is simple, fast and effective.

[0009] A further solution is that the connecting assembly includes a first support rod, a second support rod and a third support rod, and the first support rod, the second support rod and the third support rod are respectively arranged in the horizontal direction, and in the vertical direction, from bottom to top, the first support rod, the second support rod and the third support rod are arranged in sequence, and the length of the first support rod, the length of the second support rod and the length of the third support rod increase in sequence.

[0010] It can be seen that two adjacent steel arch frames are directly connected by three parallel support rods arranged in the horizontal direction, thereby enhancing the strength of the connection and ensuring the integrity of the two steel arch frames after connection.

[0011] A further solution is that a vertical connection assembly is provided between the first support rod and the second support rod and between the second support rod and the third support rod, respectively, and the vertical connection assembly includes at least one vertical support rod.

[0012] It can be seen that a vertical connection component is added between two adjacent support rods to strengthen the connection strength of the connection component and further ensure the integrity between the two adjacent steel arch frames.

[0013] A further solution is that the vertical connection assembly includes a first vertical support rod and a second vertical support rod, the first vertical support rod and the second vertical support rod are respectively connected to the first support rod and the second support rod, and the length extension direction of the first vertical support rod intersects with the length extension direction of the second vertical support rod.

[0014] A further solution is that the first support rod, the second support rod, the third support rod, the first vertical support rod and the second vertical support rod are I-beams respectively.

[0015] It can be seen that the two vertical support rods are supported between two adjacent horizontally arranged support rods along the vertical direction, which further increases the connection strength of the vertical connection assembly. The supporting effect of the I-beam is better than that of support members of other shapes.

[0016] A further solution is that a first opening is set in the left tunnel near the third intersection, a first steel arch frame is set at the first opening, and the first steel arch frame is set along the width direction of the first opening; a second opening is set in the left tunnel near the first intersection, and the last steel arch frame in the left tunnel is set along the width of the second opening.

[0017] It can be seen that since the left tunnel is obliquely intersected with the middle tunnel and the tunnel main line respectively, the first steel arch frame in the left tunnel near the third intersection is arranged along the width direction of the first opening of the left tunnel, and the last steel arch frame in the left tunnel near the first intersection is arranged along the width direction of the second opening of the left tunnel, thereby straightening the intersection position of the steel arch frames near the intersection in the left tunnel, making the overall support structure in the left tunnel more reliable and effective.

[0018] A further solution is that a first fan-shaped section and a second fan-shaped section are arranged in the left tunnel along the extension direction from the third intersection to the first intersection, the first fan-shaped section is arranged close to the third intersection, and the second fan-shaped section is arranged close to the first intersection; the width of each steel arch frame in the first fan-shaped section gradually decreases along the extension direction from the third intersection to the first intersection, and the width of each steel arch frame in the second fan-shaped section gradually increases along the extension direction from the third intersection to the first intersection.

[0019] It can be seen that along the extension direction of the left tunnel, according to the inclination law of the left tunnel, the steel arch frames in the left tunnel have different widths. This structure can straighten the steel arch frames near the intersection of the left tunnel, while making each steel arch frame in the left tunnel closer to each other, making the support structure of the left tunnel safer and more reliable.

[0020] A further solution is to provide a transverse section in the left tunnel, wherein the transverse section is provided between the first fan-shaped section and the second fan-shaped section, and within the transverse section, the width of each steel arch frame is equal.

[0021] It can be seen that along the extension direction of the inclined left tunnel, the support structure in the left tunnel is divided into "first fan-shaped section + transverse section + second fan-shaped section" as a whole, and steel arch frames of different widths are installed in different sections, making the overall support structure in the left tunnel more reliable and effective.

[0022] In order to achieve the above-mentioned second purpose, the Y-shaped auxiliary tunnel construction method provided by the present invention is the above-mentioned Y-shaped auxiliary tunnel;

[0023] The construction method includes the following steps:

[0024] First dig steps:

[0025] The construction of the middle tunnel was carried out first, and then the construction was carried out along the left and right extensions of the middle tunnel respectively;

[0026] Construction steps for the third intersection:

[0027] The construction is carried out along the left side of the middle tunnel, and the excavation from the middle tunnel stops after reaching the installation position of the first steel arch frame of the left tunnel. After the first steel arch frame of the left tunnel is installed, concrete support is sprayed immediately. Then the construction is carried out along the right side of the middle tunnel, and the excavation from the middle tunnel stops after reaching the installation position of the first steel arch frame of the right tunnel. After the first steel arch frame of the right tunnel is installed, concrete support is sprayed immediately.

[0028] Connection steps:

[0029] At the third intersection, the steel arch frames of the left tunnel, the middle tunnel and the right tunnel were connected to the connecting components in pairs, and then the excavation of the left tunnel was carried out.

[0030] It can be seen that when excavating the third intersection after the construction of the middle tunnel, the first steel arch frame of the left tunnel is installed and supported first, and then the first steel arch frame of the right tunnel is installed and supported. Then, every two adjacent steel arch frames are connected through connecting components to complete the support structure of the third intersection. The initial supporting steel arch frame of the entire area of ​​the Y-shaped auxiliary tunnel is formed into a whole, reducing the problem of stress concentration in the special-shaped area, and the construction operation of the connection structure is simple, fast and effective.

[0031] A further plan is to complete the excavation of the left tunnel and then proceed to excavate the right tunnel.

[0032] It can be seen that the construction of the left tunnel and the right tunnel is carried out in sequence to ensure the overall stability of the Y-shaped auxiliary tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the oblique connection between the auxiliary tunnel and the tunnel main line in the background technology.

[0034] Figure 2 It is a schematic diagram of another oblique connection method between the auxiliary tunnel and the tunnel main line in the background technology.

[0035] Figure 3 It is a schematic diagram of the orthogonal connection between the auxiliary tunnel and the tunnel main line in the background technology.

[0036] Figure 4 It is a schematic structural diagram of an embodiment of a Y-shaped auxiliary tunnel of the present invention.

[0037] Figure 5 It is a schematic diagram of the installation of the first connecting joint in the Y-shaped auxiliary tunnel embodiment of the present invention.

[0038] Figure 6 yes Figure 4 Schematic diagram of the connection between the first connecting joint, the second connecting joint and the third connecting joint in location A.

[0039] Figure 7 yes Figure 4 Schematic diagram of the connection between the two steel arch frames and the connecting components at C.

[0040] The present invention is further described below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0041] In the Y-shaped auxiliary tunnel of the present invention, the left tunnel corresponds to the direction of the tunnel with large mileage, and the right tunnel corresponds to the direction of the tunnel with small mileage, thereby separating the construction of large and small tunnels and reducing the interference problem at the original construction traffic gathering point. At the third intersection where the middle tunnel, the left tunnel and the right tunnel meet, the connection structure of the first connection joint, the second connection joint and the third connection joint in the central area of ​​the arch, and the connection structure formed by connecting two adjacent steel arch frames through the connection assembly in the non-central area of ​​the arch at the third intersection, plus the "first fan-shaped section + transverse section + second fan-shaped section" in the left tunnel and the right tunnel, the initial tunnel steel arch frame of the entire area of ​​the Y-shaped auxiliary tunnel is formed into a whole, while ensuring the force-bearing capacity of the overall structure and reducing the stress concentration problem in the special-shaped area. This structure is simple to construct, fast and effective.

[0042] See also Figure 4 The Y-shaped auxiliary tunnel 1 includes a left tunnel 2, a middle tunnel 3 and a right tunnel 4. The middle tunnel 3 is located between the left tunnel 2 and the right tunnel 4. The left tunnel 2 is located on the left side of the middle tunnel 3. The left tunnel 2 and the middle tunnel 3 are obliquely intersected. The right tunnel 4 is located on the right side of the middle tunnel 3. The right tunnel 4 and the middle tunnel 3 are obliquely intersected. The left tunnel 2 is used to intersect with the tunnel main line 02 to form a first intersection 5, and the right tunnel 4 is used to intersect with the tunnel main line 02 to form a second intersection 6.

[0043] In this embodiment, the left tunnel 2, the middle tunnel 3 and the right tunnel 4 intersect to form a third intersection 7. The middle tunnel 3 has no intersection with the tunnel main line 02. In the actual construction process, the middle tunnel 3 can be extended to the tunnel main line 02 and intersect with the tunnel main line 02 according to actual needs.

[0044] The middle tunnel 3 is extended in two directions to obtain the left tunnel 2 and the right tunnel 4, wherein the left tunnel 2 is obliquely intersected with the tunnel main line 02, and the left tunnel 2 is used for construction in the direction of large tunnel mileage, while the right tunnel 4 is obliquely intersected with the tunnel main line 02, and the right tunnel 4 can be used for construction in the direction of small tunnel mileage, thereby dividing the construction of large and small tunnel mileages, reducing the interference problem at the original construction traffic gathering point, and the angle formed by the left tunnel 2 and the large tunnel mileage construction direction and the angle formed by the right tunnel 4 and the small tunnel mileage construction direction are both obtuse angles, which avoids the difficulty of turning for construction machinery and vehicles, and avoids the wind resistance caused by the small angle bending of the ventilation duct in the later construction.

[0045] When the Y-shaped auxiliary tunnel 1 is excavated, support needs to be carried out while excavating. After the excavation of the middle tunnel 3 is completed, the support construction of the middle tunnel 3 is carried out. Along the extension direction of the middle tunnel 3, from the beginning of the middle tunnel 3 to the third intersection 7, multiple steel arch frames are arranged in the middle tunnel 3, and the last steel arch frame 31 of the middle tunnel 3 is arranged near the third intersection 7. The top of the steel arch frame near the third intersection 7 in the middle tunnel 3 is welded with a first connection joint 32.

[0046] After the excavation of the middle tunnel 3 is completed, when the excavation of the third intersection 7 is carried out, the excavation from the middle tunnel 3 to the installation position of the first steel arch frame 21 of the left tunnel 2 stops, and the first steel arch frame 21 of the left tunnel 2 is immediately installed, and then concrete support is sprayed, and the first steel arch frame 21 of the left tunnel 2 is set close to the third intersection 7. After the installation of the first steel arch frame 21 of the left tunnel 2 is completed, a second connection joint 22 is welded on the top of the first steel arch frame 21 of the left tunnel 2.

[0047] After the installation of the first steel arch frame 21 of the left tunnel 2 is completed, the construction of the right tunnel 4 is immediately carried out. After the first steel arch frame 41 of the right tunnel 4 is excavated from the middle tunnel 3, it stops and the first steel arch frame 41 of the right tunnel 4 is immediately installed, and concrete support is randomly sprayed. The first steel arch frame 41 of the right tunnel 4 is set near the third intersection 7. After the installation of the first steel arch frame 41 of the right tunnel 4 is completed, a third connection joint 42 is welded on the top of the first steel arch frame 41 of the right tunnel 4.

[0048] The first connection joint 32, the second connection joint 22 and the third connection joint 42 are connected to each other in pairs. In this embodiment, the first connection joint 32, the second connection joint 22 and the third connection joint 42 have the same structure. Figure 5The first connecting joint 32 includes two connecting plates 321, and the two connecting plates 321 are arranged to intersect along the length direction of the connecting plates 321. The length direction of the connecting plates 321 extends from the first steel arch frame 31 of the middle tunnel 3 to the third intersection 7. The intersection of the two connecting plates 321 is welded to the steel arch frame 21, and the two connecting plates 321 are fixedly connected. Connecting steel plates 8 are respectively provided on the two connecting plates on the first connecting joint 32, the second connecting joint 22 and the third connecting joint 42. When the first connecting joint 32, the second connecting joint 22 and the third connecting joint 42 are connected to each other in pairs, the connecting steel plate 8 on one connecting plate 321 of the first connecting joint 32 is connected to the connecting steel plate 8 on one connecting plate 221 of the second connecting plate 22 by bolts 81, and the connecting steel plate 8 on the other connecting plate 321 of the first connecting joint 32 is connected to the connecting steel plate 8 on one connecting plate 421 of the third connecting joint 42 by bolts 81; the connecting steel plate 8 on the other connecting plate 221 of the second connecting joint 22 is connected to the connecting steel plate 8 on the other connecting plate 421 of the third connecting joint 42 by bolts 81.

[0049] Since the first connection joint 32 is arranged on the top of the last steel arch frame 31 of the middle tunnel 3, the second connection joint 22 is arranged on the top of the first steel arch frame 21 of the left tunnel 2, and the third connection joint 42 is arranged on the top of the first steel arch frame 21 of the right tunnel 4, after the first connection joint 32, the second connection joint 22 and the third connection joint 42 are connected to each other, see Figure 6 A triangular connector 9 is formed in the central area of ​​the arch of the third intersection 7. In the triangular connector 9, an extended connecting plate 91 is respectively connected between the first connecting joint 32 and the second connecting joint 22, between the first connecting joint 32 and the third connecting joint 42, and between the second connecting joint 22 and the third connecting joint 42. The extended connecting plate 91 is connected to the connecting plate on the connecting joint through the connecting steel plate 8 and the bolt 81. In order to enhance the connection strength of the triangular connector 9, in the triangular connector 9, three sides are connected with reinforcing support rods 92 in pairs. In this embodiment, the reinforcing connecting plate 92 is connected between the extended connecting plates 91 on two different sides.

[0050] See also Figure 4 and Figure 6 In the third intersection 7, the first steel arch frame 21 of the left tunnel 2, the last steel arch frame 31 of the middle tunnel 3 and the first steel arch frame 41 of the right tunnel 4 are connected with a connecting assembly 10, wherein Figure 4 A connecting assembly 10 is connected between the first steel arch frame 21 of the left tunnel 2 and the last steel arch frame 31 of the middle tunnel 3 in the B position. Figure 4A connecting assembly 10 is connected between the first steel arch frame 21 of the left tunnel 2 and the first steel arch frame 41 of the right tunnel 4 in the C position. Figure 4 A connection assembly 10 is connected between the first steel arch frame of the right tunnel 4 in the D position and the last steel arch frame 31 of the middle tunnel 3. The connection assemblies 10 at three different positions are respectively located in the non-arch center area of ​​the third intersection 7, and the connection assemblies 10 at three different positions are located on the periphery of the triangular connector 9 in the arch center area of ​​the third intersection 7 along the circumference of the third intersection 7.

[0051] See also Figure 7 , the connection assembly 10 includes at least one support rod, and the support rods are respectively connected to two adjacent steel arch frames. In this embodiment, the connection assembly 10 includes a first support rod 101, a second support rod 102, a third support rod 103, a fourth support rod 104 and a plurality of vertical connection assemblies 105. The first support rod 101, the second support rod 102, the third support rod 103, and the fourth support rod 104 are respectively arranged in the horizontal direction. In the vertical direction, from the bottom to the top of the tunnel, the first support rod 101, the second support rod 102, the third support rod 103, and the fourth support rod 104 are arranged in sequence, and the lengths increase in sequence. A vertical connection assembly 105 is arranged between the first support rod 101 and the second support rod 102, a vertical connection assembly 105 is arranged between the second support rod 102 and the third support rod 103, and a vertical connection assembly 105 is arranged between the third support rod 103 and the fourth support rod 104. A vertical connection component 105 includes at least one vertical support rod. In the present embodiment, a vertical connection component 105 includes a first vertical support rod 1051 and a second vertical support rod 1052, between the first support rod 101 and the second support rod 102, and between the first vertical support rod 1051 and the second vertical support rod 1052 respectively. The length extension direction of the first vertical support rod 1051 intersects with the length extension direction of the second vertical support rod 1052.

[0052] The first support rod 101 , the second support rod 102 , the third support rod 103 , the fourth support rod, the first vertical support rod 1051 and the second vertical support rod 1052 are I-beams respectively.

[0053] In this embodiment, along the extension direction of the left tunnel 2, from the third intersection 7 to the first intersection 5, the left tunnel 2 is provided with a first fan-shaped section 23, a transverse section 24 and a second fan-shaped section 25 in sequence, the first fan-shaped section 23 is provided near the third intersection 7, the transverse section 24 is provided between the first fan-shaped section 23 and the second fan-shaped section 25, and the second fan-shaped section 25 is provided near the first intersection 5. The first fan-shaped section 23 is provided with a first opening 26 near the third intersection 7, and the first steel arch frame 21 of the left tunnel 2 is provided at the first opening 26. The first steel arch frame 21 of the left tunnel 2 is provided along the width direction of the first opening 26, and the first steel arch frame 21 is a first steel arch frame. In the first fan-shaped section 23, the width of each steel arch frame gradually decreases along the extension direction from the third intersection 7 to the first intersection 5.

[0054] In the transverse section 24, the width of each steel arch is equal.

[0055] The second sector section 25 is provided with a second opening 27 near the first intersection 5. The last steel arch frame in the left tunnel 2 is provided along the width of the second opening 27. The last steel arch frame is the second steel arch frame. The width of each steel arch frame in the second sector section 25 gradually increases along the extension direction from the third intersection 7 to the first intersection 5.

[0056] Along the extension direction of the inclined left tunnel 2, the support structure in the left tunnel 2 is divided into "first sector section + transverse section + second sector section". Steel arch frames of different widths are installed in different sections, so that the steel arch frames in the left tunnel 2 are arranged more closely. At the same time, by aligning the steel arch frames near the intersection, the overall support structure in the left tunnel 2 is more reliable and effective. The support structure in the left tunnel 2 is the same as the support structure in the right tunnel 4.

[0057] The Y-shaped auxiliary tunnel 1 construction method comprises the following steps:

[0058] The construction method includes the following steps:

[0059] First dig steps:

[0060] First, the construction of the middle tunnel 3 is carried out. According to the design requirements, the excavation is stopped when the third intersection 7 is reached, and the last steel arch frame 31 of the middle tunnel 3 is installed. The steel arch frame 31 is installed in a forward direction. The steel arch frame 31 is close to the third intersection 7. The forward installation means that the width of the last steel arch frame 31 is the maximum width of the position where the steel arch frame 31 is located in the middle tunnel 3. After the last steel arch frame 31 of the middle tunnel 3 is completed, the first connection joint 32 is set on the top of the steel arch frame 31, and then concrete spraying support is carried out.

[0061] Construction steps for the third junction 7:

[0062] The construction is carried out along the left side of the middle tunnel 3, and the excavation is stopped after the middle tunnel 3 is advanced to the installation position of the first steel arch frame 21 of the left tunnel 2. After the first steel arch frame 21 of the left tunnel 2 is installed, the second connection joint 22 is welded on the top of the first steel arch frame 21 of the left tunnel 2, and then concrete support is sprayed; then the construction of the right tunnel 4 is carried out, and the excavation is stopped after the middle tunnel 3 is advanced to the installation position of the first steel arch frame 41 of the right tunnel 4. After the first steel arch frame 41 of the right tunnel 4 is installed, the third connection joint 42 is set on the top of the first steel arch frame 41 of the right tunnel 4, and then concrete support is sprayed;

[0063] Connection steps:

[0064] In the third intersection 7, after the steel arches and shotcrete in the first fan-shaped sections of the left and right tunnels are completed, the first connection joints 32, the second connection joints 22 and the third connection joints 42 in the third intersection 7 are connected in pairs; then the first steel arches of the left tunnel 2, the first steel arches of the middle tunnel 3 and the first steel arches of the right tunnel 4 are connected in pairs through the connection components 10 respectively; in the actual installation process, the triangular connector and the connection component can be installed in the third intersection 7 or both at the same time;

[0065] The steps for continuing the excavation of the left tunnel 2 are as follows:

[0066] After completing the setting of the support structure of the third intersection 7, the construction is organized according to the principle of first excavating the left side and supporting the large mileage, and the excavation of the left tunnel 2 is continued. The excavation support is carried out according to the combination of "first fan-shaped section-transverse section-second fan-shaped section" until the first intersection 5 is reached, and the top adjustment construction is carried out;

[0067] The steps for continuing the excavation of tunnel 4 on the right side are as follows:

[0068] After completing the construction of the left tunnel 2, the construction is organized according to the right excavation and support to the small mileage construction, and the excavation of the right tunnel 4 is carried out. The excavation support is carried out according to the combination of "first fan-shaped section-transverse section-second fan-shaped section" until the second intersection 6 is reached, and the top adjustment construction is carried out;

[0069] Support construction steps:

[0070] After the excavation work of the left tunnel 2 and the right tunnel 4 is completed, the overall support construction and operation of the Y-shaped auxiliary tunnel will be carried out.

[0071] Finally, it should be emphasized that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Y-shaped auxiliary tunnel, characterized by: include: A left tunnel, a middle tunnel and a right tunnel, wherein the middle tunnel is located between the left tunnel and the right tunnel, the left tunnel is located on the left side of the middle tunnel, and the left tunnel obliquely intersects with the middle tunnel, and the right tunnel is located on the right side of the middle tunnel, and the right tunnel obliquely intersects with the middle tunnel; The left tunnel is used to intersect with the tunnel main line to form a first intersection, the right tunnel is used to intersect with the tunnel main line to form a second intersection, and the left tunnel, the middle tunnel and the right tunnel intersect to form a third intersection; The left tunnel, the middle tunnel and the right tunnel are respectively provided with steel arch frames near the third intersection. In the third intersection, the steel arch frames of the left tunnel, the steel arch frames of the middle tunnel and the steel arch frames of the right tunnel are connected with connection components in pairs, and the connection components are located in the non-arch center area of ​​the third intersection; The connecting assembly includes a first support rod, a second support rod, a third support rod and a fourth support rod. The first support rod, the second support rod, the third support rod and the fourth support rod are respectively arranged in the horizontal direction. In the vertical direction, from bottom to top, the first support rod, the second support rod and the third support rod are arranged in sequence, and the length of the first support rod, the length of the second support rod and the length of the third support rod and the fourth support rod increase in sequence.

2. The Y-shaped auxiliary tunnel according to claim 1, characterized in that : A vertical connection assembly is provided between the first support rod and the second support rod, and between the second support rod and the third support rod, respectively. The vertical connection assembly includes at least one vertical support rod.

3. The Y-shaped auxiliary tunnel according to claim 2, characterized in that : The vertical connection assembly includes a first vertical support rod and a second vertical support rod. The first vertical support rod and the second vertical support rod are respectively connected to the first support rod and the second support rod. The length extension direction of the first vertical support rod intersects with the length extension direction of the second vertical support rod.

4. The Y-shaped auxiliary tunnel according to claim 3, characterized in that : The first support rod, the second support rod, the third support rod, the first vertical support rod and the second vertical support rod are I-beams respectively.

5. The Y-shaped auxiliary tunnel according to any one of claims 1 to 4, characterized in that : The left tunnel is arranged at a first opening near the third intersection, a first steel arch frame is arranged at the first opening, and the first steel arch frame is arranged along the width direction of the first opening; A second opening is arranged in the left tunnel near the first intersection, and a second steel arch frame in the left tunnel is arranged along the width of the second opening.

6. The Y-shaped auxiliary tunnel according to claim 5, characterized in that : Along the extension direction from the third intersection to the first intersection in the left tunnel, a first fan-shaped section and a second fan-shaped section are arranged in the left tunnel, the first fan-shaped section is arranged close to the third intersection, and the second fan-shaped section is arranged close to the first intersection; The width of each steel arch frame in the first fan-shaped section gradually decreases along the extension direction from the third intersection to the first intersection, and the width of each steel arch frame in the second fan-shaped section gradually increases along the extension direction from the third intersection to the first intersection.

7. The Y-shaped auxiliary tunnel according to claim 6, characterized in that : A transverse section is provided in the left tunnel, and the transverse section is provided between the first fan-shaped section and the second fan-shaped section. In the transverse section, the width of each steel arch frame is equal.

8. The Y-shaped auxiliary tunnel construction method is characterized by: The Y-shaped auxiliary tunnel is the Y-shaped auxiliary tunnel according to any one of claims 1 to 7; The construction method includes the following steps: First dig steps: First, the middle tunnel is constructed, and then the left and right extensions of the middle tunnel are constructed respectively; Construction steps for the third intersection: Construction is carried out along the left side of the middle tunnel, and the tunnel is excavated from the middle tunnel to the installation position of the first steel arch frame of the left tunnel, and then concrete support is sprayed after the first steel arch frame of the left tunnel is installed. Then construction is carried out along the right side of the middle tunnel, and the tunnel is excavated from the middle tunnel to the installation position of the first steel arch frame of the right tunnel, and then concrete support is sprayed after the first steel arch frame of the right tunnel is installed. Connection steps: In the third intersection, the first steel arch frame of the left tunnel, the first steel arch frame of the middle tunnel and the first steel arch frame of the right tunnel are respectively connected to the connecting components, and then the excavation of the left tunnel is carried out.

9. The Y-shaped auxiliary tunnel construction method according to claim 8, characterized in that: After completing the excavation of the left tunnel, the excavation of the right tunnel is carried out.

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