Annular double-layer lining structure for tunnel ventilation and construction method

Abstract

The invention provides an annular double-layer lining structure for tunnel ventilation and a construction method, and relates to the technical field of tunnel construction.The structure comprises a tunnel main line, the tunnel main line comprises a tunnel left line and a tunnel right line, the tunnel left line communicates with the tunnel right line through a transverse channel, and the tunnel right line is connected with an air duct; a layer of lining is additionally arranged on the outer side of an original secondary lining structure of a tunnel right line, an annular double-layer lining system is formed, and excavation, primary supporting and lining construction of the structure are completed in a gradual change expanding excavation and reverse expanding excavation construction mode. The ventilation structure has the beneficial effects that the ventilation problem of the tunnel is effectively solved, the construction difficulty is reduced, and the overall stability of the main body structure is enhanced.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to an annular double-layer lining structure and construction method for tunnel ventilation. Background Technology

[0002] In tunnel engineering, as tunnel length increases and geological conditions become more complex, ventilation within the tunnel becomes a critical issue affecting construction safety and operational efficiency. If harmful gases, dust, and heat generated during construction and operation cannot be effectively removed, they can threaten personnel health, cause safety accidents, and affect equipment operation and structural durability.

[0003] Existing ventilation methods mostly rely on mechanical ventilation equipment or single air ducts, which suffer from low efficiency, high energy consumption, and high maintenance costs in long-distance, large-section tunnels. Some projects have added ventilation channels by modifying existing structures, but traditional construction methods require excavation or demolition of the main structure, which can easily disturb the main tunnel line, damage structural integrity, and increase safety risks.

[0004] Traditional single-layer lining structures focus solely on the load-bearing capacity of the surrounding rock, making it difficult to accommodate the needs of ventilation duct construction. Temporarily adjusting the lining method increases construction difficulty, prolongs the construction period, and may lead to cracking and leakage due to unreasonable stress distribution. Furthermore, the connections between the tunnel and cross passages / ventilations are prone to problems such as untimely support and loose connections due to complex stress and limited space, exacerbating safety hazards.

[0005] Therefore, there is an urgent need to develop a lining structure that combines ventilation and structural reinforcement functions, so as to effectively solve ventilation problems and reduce the impact of construction while ensuring the stability of the main structure.

[0006] How to solve the above-mentioned technical problems is the challenge facing this invention. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a ring-shaped double-layer lining structure and construction method for tunnel ventilation that not only effectively solves the ventilation problem in tunnels but also reduces construction difficulty and enhances the overall stability of the main structure.

[0008] The technical solution adopted by the present invention to solve its technical problem is as follows: The present invention provides an annular double-layer lining structure for tunnel ventilation. The structure includes a tunnel main line, the tunnel main line includes a tunnel left line and a tunnel right line, the tunnel left line and the tunnel right line are connected by a cross passage, and the tunnel right line is connected to a ventilation duct. An additional layer of lining is added to the outside of the original secondary lining structure of the right tunnel, forming a ring-shaped double-layer lining system.

[0009] The upper left step of the tunnel consists of the initial support structure and the secondary lining structure of the upper left step, while the lower step consists of the initial support structure and the secondary lining structure of the lower left step, forming a closed-loop system.

[0010] The connection between the right side of the left tunnel and the cross passage is not lined, and is used for ventilation of the left tunnel.

[0011] The cross passage consists of the initial support structure of the tunnel cross passage and the secondary lining structure of the tunnel cross passage. The right tunnel is composed of a double-layer lining structure, and the gap between the double-layer lining structure is connected to the transverse passage. The air in the left tunnel enters the double-layer lining structure of the right tunnel through the cross passage.

[0012] The upper step of the first layer of the double-layer lining structure of the right tunnel consists of the initial support structure of the upper step of the right tunnel and the first layer of the second lining structure of the upper step of the right tunnel, while the lower step consists of the initial support structure of the lower step of the right tunnel and the second lining structure of the lower step of the right tunnel. The second layer of the right tunnel lining does not have a separate invert arch. Instead, it is connected to the first layer of the invert arch by pre-reserved steel bars to form a closed ring structure.

[0013] The space between the arch bottoms on both sides of the second layer of the right tunnel lining structure and the arch bottoms on both sides of the first layer of lining structure is filled and sealed with concrete material, including the filling material on the left side of the arch bottom and the filling material on the right side of the arch bottom.

[0014] The tunnel ventilation duct consists of an initial support structure and a secondary lining structure. The left tunnel, cross passage, right tunnel, and ventilation duct are connected as an integral structure, which on the one hand meets the stable ventilation requirements of the left tunnel ZX, and on the other hand ensures the overall stability of the right tunnel YX.

[0015] A construction method for a ring-shaped double-layer lining structure for tunnel ventilation, comprising the following steps: S1. When the right tunnel line transitions from the standard cross-section to the enlarged cross-section, at the junction of the two, the tunnel face will start the gradual enlargement construction by combining the outer angle of the enlarged excavation and the longitudinal length until the enlarged cross-section is designed to be excavated. After the tunnel face is advanced to the enlarged cross-section position, it is necessary to continue construction for a certain distance, during which the initial support structure of the right upper bench and the initial support structure of the right lower bench of the tunnel are gradually constructed. S2. Carry out reverse excavation operation on the gradually widened section. After excavating to the corresponding size of the enlarged cross section, promptly construct the initial support structure of the right-side bench of the tunnel at that cross section. Subsequently, the excavation and initial support of the enlarged cross-section continued until it approached the standard cross-section. Then, the excavation size was reduced in accordance with the design outline to complete all excavation and initial support work of the enlarged cross-section. S3. After the right tunnel face has been excavated to a certain safe distance, excavation and initial support work will be carried out gradually in combination with the design dimensions of the cross passage and ventilation duct until the cross passage is connected to the right side of the left tunnel. S4. When there is sufficient space for the construction of the invert arch and secondary lining at the location of the section to be enlarged, the construction of the double-layer lining structure shall commence: First, the construction of the invert arch structure of the right lower step of the tunnel is completed. Then, a special secondary lining trolley with an enlarged cross-section is used to carry out the secondary lining construction, that is, to complete the construction of the first layer of secondary lining structure of the right upper step of the tunnel. Among them, in combination with the design dimensions of the second layer of secondary lining structure of the right tunnel, steel bars are reserved at the joint position of the first layer of secondary lining structure of the right upper step of the tunnel. In addition, the first layer of secondary lining structure of the right upper step of the tunnel needs to reserve positions without lining structure construction in combination with the design dimensions of the cross passage and ventilation duct. S5. After the first layer of lining structure is constructed to a certain safe distance, the construction of the second layer of lining structure on the right line of the tunnel is started by using a standard cross-section lining trolley. The reserved steel bars of the first layer of lining structure on the right line of the tunnel are used to connect it to the first layer of lining structure to form a whole. The arch bottoms on both sides of the second layer of lining structure on the right line of the tunnel are filled and sealed with concrete material between the arch bottoms on both sides of the first layer of lining structure to ensure uniform stress on both sides. Finally, the construction of the annular double-layer lining structure for tunnel ventilation was completed.

[0016] Among them, the external angle of the enlarged cross section needs to meet the drilling angle of the double-bend rock drilling rig. The longitudinal length of the enlarged section is: (the difference in height between the top of the enlarged section and the standard section) / tan (external angle of the enlarged section).

[0017] The beneficial effects of this invention are as follows: 1. The annular double-layer lining structure adopted in this invention can meet the stable ventilation requirements inside the tunnel on the one hand, and reduce the disturbance of construction to the main tunnel structure on the other hand, significantly enhancing the overall stability of the main structure. 2. The construction method of the annular double-layer lining structure of the present invention, by means of gradual excavation and reverse excavation technology, not only reduces the construction difficulty of the ventilation structure of the same tunnel, but also reduces the construction risk and effectively improves the construction safety. 3. A novel annular double-layer lining structure and construction method are provided for ventilation inside tunnels. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the annular double-layer lining structure for tunnel ventilation according to the present invention.

[0019] Figure 2This is a schematic diagram of the standard cross-section construction of the annular double-layer lining structure used for tunnel ventilation according to the present invention.

[0020] Figure 3 This is a schematic diagram of the gradually widened excavation construction of the annular double-layer lining structure for tunnel ventilation according to the present invention.

[0021] Figure 4 This is a schematic diagram of the enlarged cross-section construction of the annular double-layer lining structure for tunnel ventilation according to the present invention.

[0022] Figure 5 This is a schematic diagram of the reverse excavation construction of the annular double-layer lining structure for tunnel ventilation according to the present invention.

[0023] Figure 6 This is a schematic diagram illustrating the construction of the annular double-layer lining structure for tunnel ventilation of the present invention, which expands the cross-section to the standard cross-section.

[0024] Figure 7 This is a schematic diagram of the construction of the annular double-layer lining structure cross passage and air duct for tunnel ventilation according to the present invention.

[0025] The attached diagrams are labeled as follows: ZX, left tunnel; HTD, tunnel cross passage; YX, right tunnel; FD, tunnel ventilation duct; 111, initial support structure of the upper bench of the left tunnel; 121, secondary lining structure of the upper bench of the left tunnel; 112, initial support structure of the lower bench of the left tunnel; 122, secondary lining structure of the lower bench of the left tunnel; 211, initial support structure of the tunnel cross passage; 221, secondary lining structure of the tunnel cross passage; 311, initial support structure of the upper bench of the right tunnel; 321, first layer secondary lining structure of the upper bench of the right tunnel; 312, initial support structure of the lower bench of the right tunnel; 322, secondary lining structure of the lower bench of the right tunnel; 323, tunnel... Second lining structure of the right tunnel; TC1, left side filling material of the arch bottom; TC2, right side filling material of the arch bottom; 411, initial support structure of the tunnel ventilation duct; 421, secondary lining structure of the tunnel ventilation duct; 11, gradual widening excavation construction on the left side of the enlarged cross-section of the right tunnel; 12, gradual widening excavation construction on the right side of the enlarged cross-section of the right tunnel; 21, construction of the enlarged cross-section on the left side of the right tunnel; 22, construction of the enlarged cross-section on the right side of the right tunnel; 31, reverse widening excavation construction on the left side of the right tunnel; 32, reverse widening excavation construction on the right side of the right tunnel; 41, construction of the standard section on the left side of the right tunnel; 42, construction of the standard section on the right side of the right tunnel; KDDM, enlarged cross-section; BZDM2, standard cross-section. Detailed Implementation

[0026] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0027] See Figures 1 to 2As shown, this embodiment is a ring-shaped double-layer lining structure for tunnel ventilation. The structure includes a tunnel main line, which includes a left tunnel line ZX and a right tunnel line YX. The left tunnel line ZX and the right tunnel line YX are connected by a cross passage HTD. The right tunnel line YX is connected to the ventilation duct FD. It includes a standard cross section BZDM2 and an enlarged cross section KDDM. The standard cross section BZDM2 is the normal design cross section, and the enlarged cross section KDDM is the cross section with a larger cross section size. An additional layer of lining is added to the outside of the original secondary lining structure of the right tunnel YX, forming a ring-shaped double-layer lining system.

[0028] The upper bench of the left tunnel ZX consists of the initial support structure 111 and the secondary lining structure 121 of the upper bench of the left tunnel, while the lower bench consists of the initial support structure 112 and the secondary lining structure 122 of the lower bench of the left tunnel, forming a closed-loop system.

[0029] No lining structure will be constructed at the connection point between the right side of the left tunnel ZX and the cross passage HTD.

[0030] The transverse passage HTD consists of the initial support structure 211 of the transverse passage and the secondary lining structure 221 of the transverse passage. The right tunnel YX consists of a double-layer lining structure, and the gap between the double-layer lining structure is connected to the cross passage HTD. Air from the left tunnel (ZX) enters the double-layer lining structure of the right tunnel (YX) via the cross passage (HTD).

[0031] The upper step of the first layer of the double-layer lining structure of the right tunnel YX consists of the initial support structure 311 of the upper step of the right tunnel and the first layer of the secondary lining structure 321 of the upper step of the right tunnel, while the lower step consists of the initial support structure 312 of the lower step of the right tunnel and the secondary lining structure 322 of the lower step of the right tunnel. The second layer of the right tunnel lining structure 323 does not have a separate invert arch. Instead, it is connected to the first layer of invert arch by the reserved steel bars to form a whole, creating a closed ring structure.

[0032] The space between the arch bottoms on both sides of the second layer lining structure 323 on the right line of the tunnel and the arch bottoms on both sides of the first layer lining structure is filled and sealed with concrete material, including the filling material TC1 on the left side of the arch bottom and the filling material TC2 on the right side of the arch bottom.

[0033] The tunnel ventilation duct FD consists of the initial support structure 411 and the secondary lining structure 421.

[0034] The excavation and support construction of the annular double-layer lining structure includes: In the initial stage of construction, the left tunnel ZX is constructed normally first, followed by the completion of the initial support structure 111 of the upper step of the left tunnel, the initial support structure 112 of the lower step of the left tunnel, the secondary lining structure 122 of the lower step of the left tunnel, and the initial support structure 121 of the lower step of the left tunnel; at the same time, the excavation of the standard section BZDM2 face of the right tunnel YX is promoted; after the right tunnel face reaches the position of the enlarged section KDDM, the gradual enlargement excavation is carried out on the left and right sides of the tunnel respectively, based on the drilling angle, namely the gradual enlargement excavation construction 11 on the left side of the enlarged section of the right tunnel and the gradual enlargement excavation construction 12 on the right side of the enlarged section of the right tunnel, until the enlargement is carried out to the design size of the enlarged section KDDM; Subsequently, excavation continues forward a certain distance along the left-side enlarged section 21 and the right-side enlarged section 22 of the right tunnel (this distance is sufficient for reverse excavation). During the excavation, the initial support structure 311 for the upper bench and the initial support structure 312 for the lower bench of the right tunnel are successively completed. Next, based on the design dimensions of the enlarged section, reverse excavation is carried out on the left-side gradually enlarged section 31 and the right-side reverse excavation 32 of the right tunnel. After all excavation reaches the design dimensions of the enlarged section KDDM, the initial support structure 311 for the upper bench and the initial support structure 312 for the lower bench of the right tunnel are then completed. Finally, excavation and initial support work continue to advance along the design dimensions of the enlarged section KDDM until approaching the standard section BZDM2. Then, the excavation outline of the left-side standard section 41 and the right-side standard section 42 of the right tunnel is reduced according to the design dimensions, thus completing the entire process of excavation and support work for the enlarged section.

[0035] Furthermore, after the tunnel faces of the left tunnel ZX and the right tunnel YX are excavated to a certain safe distance, the excavation of the cross passage HTD and the initial support structure 211 of the tunnel cross passage, the excavation of the ventilation duct FD and the initial support structure 411 of the tunnel ventilation duct are completed in accordance with the design dimensions, until the cross passage HTD is connected to the right side of the left tunnel ZX and the ventilation duct FD is connected to the right side of the right tunnel YX.

[0036] The construction of the annular double-layer lining structure includes: when there is sufficient space for the construction of the invert arch and secondary lining at the enlarged cross-section KDDM location, the construction of the double-layer lining structure is carried out. First, the construction of the secondary lining structure 322 of the right lower bench of the tunnel is completed. Then, the secondary lining work is carried out using a special secondary lining trolley for the enlarged cross-section, that is, the construction of the first layer of secondary lining structure 321 of the right upper bench of the tunnel is completed. Among them, in combination with the design dimensions of the second layer of secondary lining structure 323 of the right tunnel, steel bars are reserved at the connection position of the first layer of secondary lining structure 321 of the right upper bench of the tunnel. In addition, the right tunnel... The first layer of the secondary lining structure 321 of the upper step needs to be constructed without lining work in the reserved positions according to the design dimensions of the cross passage HTD and ventilation duct FD. After the construction of the first layer of lining structure reaches a certain safe distance, the construction of the second layer of the secondary lining structure 323 of the right line of the tunnel will begin using a standard cross-section secondary lining trolley, and the reserved steel bars of the first layer of the secondary lining structure 321 of the upper step of the right line of the tunnel will be used to connect it to the second layer of lining structure 321 to form a whole. Among them, the arch bottoms on both sides of the second layer of lining structure 323 of the right line of the tunnel and the arch bottoms on both sides of the first layer of lining structure are filled and sealed with concrete material to ensure uniform stress on both sides.

[0037] Finally, the construction of the annular double-layer lining structure was completed.

[0038] The technical features of this invention not described can be implemented by or using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this invention, and this invention is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention should also be within the protection scope of this invention.

Claims

1. A ring-shaped double-layer lining structure for tunnel ventilation, characterized in that, The structure includes a main tunnel line, which includes a left tunnel line (ZX) and a right tunnel line (YX). The left tunnel line (ZX) and the right tunnel line (YX) are connected by a cross passage (HTD), and the right tunnel line (YX) is connected to a ventilation duct (FD). An additional layer of lining is added to the outside of the original secondary lining structure of the right tunnel (YX), forming a ring-shaped double-layer lining system.

2. The annular double-layer lining structure for tunnel ventilation according to claim 1, characterized in that, The upper step of the left tunnel (ZX) consists of the initial support structure (111) of the upper step of the left tunnel and the secondary lining structure (121) of the upper step of the left tunnel, and the lower step consists of the initial support structure (112) of the lower step of the left tunnel and the secondary lining structure (122) of the lower step of the left tunnel, forming a closed loop system.

3. The annular double-layer lining structure for tunnel ventilation according to claim 1, characterized in that, No lining structure is constructed at the connection point between the right side of the left tunnel (ZX) and the cross passage (HTD).

4. The annular double-layer lining structure for tunnel ventilation according to claim 1, characterized in that, The transverse tunnel (HTD) consists of the initial support structure (211) of the transverse tunnel and the secondary lining structure (221) of the transverse tunnel.

5. The annular double-layer lining structure for tunnel ventilation according to claim 1, characterized in that, The right tunnel (YX) is composed of a double-layer lining structure, and the gap between the double-layer lining structure is connected to the transverse passage (HTD). Air from the left tunnel (ZX) enters the double-layer lining structure of the right tunnel (YX) through the transverse passage (HTD).

6. The annular double-layer lining structure for tunnel ventilation according to claim 1, characterized in that, The upper step of the first layer of the double-layer lining structure of the right tunnel (YX) consists of the initial support structure (311) of the upper step of the right tunnel and the first layer of the secondary lining structure (321) of the upper step of the right tunnel, while the lower step consists of the initial support structure (312) of the lower step of the right tunnel and the secondary lining structure (322) of the lower step of the right tunnel. The second layer of the right tunnel lining structure (323) does not have a separate invert arch. Instead, it is connected to the first layer of invert arch by the reserved steel bars to form a closed ring structure.

7. The annular double-layer lining structure for tunnel ventilation according to claim 1, characterized in that, The arch bottoms on both sides of the second layer lining structure (323) of the right tunnel are sealed with concrete material between the arch bottoms on both sides of the first layer lining structure, including the left side filling material (TC1) and the right side filling material (TC2).

8. The annular double-layer lining structure for tunnel ventilation according to claim 1, characterized in that, The tunnel ventilation duct (FD) consists of the initial support structure (411) and the secondary lining structure (421).

9. A construction method for a ring-shaped double-layer lining structure for tunnel ventilation as described in any one of claims 1-8, characterized in that, Includes the following steps: When the right tunnel (YX) transitions from the standard cross-section (BZDM2) to the enlarged cross-section (KDDM) at the junction of the two, the tunnel face will initiate gradual enlargement construction by combining the external angle of the enlargement and the longitudinal length, until the enlarged cross-section is designed to be excavated. After the tunnel face advances to the enlarged cross section (KDDM) position, it is necessary to continue construction for a certain distance, during which the initial support structure (311) of the upper bench of the right tunnel and the initial support structure (312) of the lower bench of the right tunnel are gradually constructed. S2. Carry out reverse excavation operation on the gradually widened section. After excavating to the corresponding size of the enlarged cross section (KDDM), promptly construct the initial support structure (311) of the right-side bench of the tunnel at that cross section. Subsequently, the excavation and initial support of the enlarged cross section (KDDM) continued until it approached the standard cross section (BZDM2). Then, the excavation size was reduced in accordance with the design outline to complete all excavation and initial support work of the enlarged cross section (KDDM). S3. After the right tunnel (YX) face has been excavated to a certain safe distance, excavation and initial support work will be carried out gradually in combination with the design dimensions of the cross passage (HTD) and ventilation duct (FD) until the cross passage (HTD) is connected to the right side of the left tunnel (ZX). S4. When there is sufficient space for the construction of the invert arch and secondary lining at the location of the section to be enlarged (KDDM), the construction of the double-layer lining structure shall be carried out: First, the construction of the inverted arch structure (322) of the right lower step of the tunnel was completed. Then, the secondary lining operation was carried out by using a special secondary lining trolley with an enlarged cross section, that is, the construction of the first layer of secondary lining structure (321) of the right upper step of the tunnel was completed. The first layer of the secondary lining structure (321) of the right-hand platform of the tunnel needs to be designed in conjunction with the cross passage (HTD) and ventilation duct (FD) to reserve the space where no lining structure work is carried out; S5. After the first layer of lining structure is constructed to a certain safe distance, the construction of the second layer of lining structure (323) on the right line of the tunnel is started by using a standard cross-section lining trolley, and the reserved steel bars of the first layer of lining structure (321) on the right side of the tunnel are used to connect it to the whole. The arch bottoms on both sides of the second layer of the tunnel lining structure (323) on the right line are filled and sealed with concrete material between the arch bottoms on both sides of the first layer of the lining structure to ensure uniform stress on both sides; Finally, the construction of the annular double-layer lining structure for tunnel ventilation was completed.

10. The construction method of the annular double-layer lining structure for tunnel ventilation according to claim 9, characterized in that, The enlarged cross section (KDDM) excavation angle needs to meet the drilling angle of the double-bend drilling rig. The longitudinal length of the enlarged section is (the difference in height between the top of the enlarged section and the standard section) / tan (excavation angle).

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