A blasting protection type tunnel construction method

Abstract

The application provides a blasting protection type tunnel construction method, A, a protection shed is built in the region of a mountain body at a tunnel entrance and is aligned with the tunnel entrance; B, starting to dig a tunnel: B1, cutting the periphery of the region where the tunnel is built on one side of the mountain body where the tunnel is built to form a vibration absorption groove extending along the contour line of the tunnel, the wall surface on one side of the tunnel center is a stepped surface with two steps; B2, building a vibration absorption structure at the excavation end of the tunnel; B3, blasting the region surrounded by the vibration absorption groove, transporting the blasted rock outside the tunnel, thereby completing the excavation of a section of the tunnel, and repeating steps B1 to B3 until the tunnel is through. The application aims to provide a blasting protection type tunnel construction method capable of preventing vibration energy from overflowing to reduce the interference of blasting tunnel construction on surrounding buildings and mountain bodies, and is used to solve the problem of great influence of rock stratum geological blasting method on the surrounding region when the tunnel is built.

Description

Technical Field

[0001] This application relates to the field of tunnel construction technology, and in particular to a method for blast-protected tunnel construction. Background Technology

[0002] Tunnels are built during road construction, and the traditional construction methods for tunnels are mechanical excavation and blasting. Mechanical excavation is only suitable for geological conditions with low rock strength; blasting is used for rocky geological conditions, but the vibrations generated by blasting have a significant impact on nearby tunnel structures and the surrounding mountains. Summary of the Invention

[0003] This invention aims to provide a blast-protected tunnel construction method that can prevent vibration energy leakage and reduce the interference of blasting tunnel construction on surrounding buildings and mountains, in order to solve the problem of the large impact on the surrounding area when constructing tunnels using the rock strata blasting method.

[0004] To achieve the above-mentioned objectives, the present invention employs the following technology: a blasting-protected on-site construction method, characterized in that: A) a protective shed aligned with the tunnel entrance is erected in the area of ​​the mountain where the tunnel entrance is located; B) tunnel excavation begins: B1) the perimeter of the tunnel construction area is cut off on one side of the mountain where the tunnel is to be constructed, forming a vibration damping groove extending along the tunnel outline, the wall of the vibration damping groove on the side of the tunnel center being a stepped surface with two levels of steps; B2) a vibration damping structure is constructed at the excavation end of the tunnel; B3) the area enclosed by the vibration damping groove is blasted, and the blasted rock is transported outside the tunnel, thereby completing the excavation of a section of the tunnel, repeating steps B1 to B3 until the tunnel is completed; the protective shed includes a structure connected to the tunnel entrance. The tunnel consists of a rear gantry, an arched canopy connected to the rear end of the rear gantry, and a front gantry connected to the front end of the arched canopy. The arched canopy includes an inner arched frame, an arched steel mesh supported on the inner arched frame, and a rubber sheet covering the steel mesh. The inner arched frame includes several steel arches distributed along the tunnel depth direction. Each steel arch has a connecting end plate with bolt holes at both ends. The connecting end plate is a steel structure and is fixed to the ground by a fixing structure. When the inner arched frame is connected to the tunnel entrance, the entire tunnel entrance is located within the space enclosed by the arched canopy. The first steel arch is connected to the front gantry, and the last steel arch is connected to the rear gantry. The front gantry is equipped with a structure to enclose the inner arched frame. The front explosion-proof curtain at the front end of the frame is connected to the front mast only at its upper end. The rear mast has a rear explosion-proof curtain that closes the rear end of the arched inner frame. The rear explosion-proof curtain is connected to the rear mast only at its upper end. The vibration damping structure includes a first vertical vibration damping ring, a second vertical vibration damping ring, and a vertical vibration damping cover. The specific process in part B2 is as follows: the first vertical vibration damping ring is installed on the step at the bottom of the vibration damping groove, extending along the extension direction of the vibration damping groove; the second vertical vibration damping ring is installed on another step, extending along the extension direction of the vibration damping groove; and the vertical vibration damping cover covers the area enclosed by the vibration damping groove. The first vertical vibration damping ring includes a first vertical vibration damping ring portion that is sequentially nested together and then vertically compressed. The first vertical vibration damping ring consists of a ring, a vertical compression ring inside the first vertical vibration damping ring section, and an annular vibration damping plate in the first vertical vibration damping ring section. The inner circumferential surface of the outer vertical compression ring of the first vertical vibration damping ring section is an inclined surface that slopes towards the direction of the vertical vibration damping cover. The outer circumferential surface of the inner vertical compression ring of the first vertical vibration damping ring section is an inclined surface that slopes away from the direction of the vertical vibration damping cover. The inner circumferential surface of the outer vertical compression ring of the first vertical vibration damping ring section abuts against the outer circumferential surface of the inner vertical compression ring of the first vertical vibration damping ring section. The annular vibration damping plate of the first vertical vibration damping ring section is connected to the inner vertical compression ring of the first vertical vibration damping ring section through several damping springs of the first vertical vibration damping ring section. The inner vertical compression ring of the first vertical vibration damping ring section has an inner flange at one end facing the vertical vibration damping cover.The second vertical vibration damping ring includes an outer vertical compression ring, an inner vertical compression ring, and an annular damping plate of the second vertical vibration damping ring, all nested together in sequence. The inner circumferential surface of the outer vertical compression ring is an inclined surface oriented towards the direction of the vertical damping cover, while the outer circumferential surface of the inner vertical compression ring is an inclined surface oriented away from the direction of the vertical damping cover. The inner circumferential surface of the outer vertical compression ring abuts against the outer circumferential surfaces of the inner and outer vertical compression rings. The annular damping plate of the second vertical vibration damping ring is connected to the inner vertical compression ring of the second vertical vibration damping ring via several damping springs. The end of the ring facing the vertical vibration damping cover has a second vertical vibration damping ring inner flange. The outer vertical compression ring of the second vertical vibration damping ring is located inside the space enclosed by the projection of the annular vibration damping plate of the first vertical vibration damping ring along the center line of the first vertical vibration damping ring. A vibration damping groove is formed between the outer vertical compression ring of the second vertical vibration damping ring and the tunnel wall. The vertical vibration damping cover includes an inner cover plate and an outer cover plate. The inner cover plate is connected to the inner flange of the first vertical vibration damping ring via a first push rod, and abuts against the inner flange of the second vertical vibration damping ring. The outer cover plate is connected to the outer vertical compression ring of the first vertical vibration damping ring via a first pull rod and to the outer vertical compression ring of the second vertical vibration damping ring via a second pull rod. This technical solution retains the advantage of rapid blasting construction while reducing the impact of blasting on the surrounding area. It can effectively eliminate the energy spilled from the blast.

[0005] Preferably, the outer cover plate has a plurality of energy-dissipating through holes, and the inner cover plate has conical energy-dissipating heads that are correspondingly inserted into the energy-dissipating through holes. The diameter of the conical energy-dissipating head furthest from the outer cover plate is larger than the diameter of the energy-dissipating through holes. The outer cover plate is supported on the conical energy-dissipating heads and connected to the inner cover plate. This design achieves good energy dissipation.

[0006] Preferably, the conical energy-absorbing head is fitted with an outer shell, the hardness of which is lower than that of the outer cover plate. During energy absorption, the outer shell is the first part to be damaged, and it can be replaced for reuse. This allows the vertical vibration-damping cover to be easily reused.

[0007] Preferably, the surface of the conical energy dissipation head is provided with a friction layer, resulting in good energy absorption.

[0008] Preferably, the outer circumferential surface of the outer vertical compression ring of the first vertical vibration damping ring is provided with a first vertical vibration damping ring explosive charge. The force generated when the first vertical vibration damping ring explosive charge detonates drives the outer vertical compression ring of the first vertical vibration damping ring to move away from the vertical vibration damping cover and towards the tunnel center. The outer circumferential surface of the outer vertical compression ring of the second vertical vibration damping ring is provided with a second vertical vibration damping ring explosive charge. The force generated when the second vertical vibration damping ring explosive charge detonates drives the outer vertical compression ring of the first vertical vibration damping ring to move away from the vertical vibration damping cover and towards the tunnel center. In step B3, the first and second vertical vibration damping ring explosive charges are detonated simultaneously with the blasting of the portion located within the space enclosed by the vibration damping groove. This can more effectively and fully reduce spilled energy.

[0009] Preferably, the front and rear gantry frames have identical structures. The front gantry includes a left steel column, a right steel column, horizontal steel bars connected at both ends to the upper ends of the left and right steel columns, a left diagonal support connecting the left steel column to the horizontal steel bars, a right diagonal support connecting the right steel column to the horizontal steel bars, several horizontal supports connecting the left steel column to the first steel arch, and a vertical support connecting the horizontal steel bars to the first steel arch. The front explosion-proof curtain is connected to the horizontal steel bars. The left diagonal support, horizontal supports, right diagonal support, and vertical support are all steel structures, providing good strength.

[0010] Preferably, both the left and right steel columns are provided with gantry section connecting end plates at their lower ends, which have bolt holes for the gantry section. The gantry section connecting end is a steel structure, facilitating fixing.

[0011] Preferably, the connecting end plate of the gantry section is fixed to the ground by a fixing structure. This fixing structure includes a concrete pier cast into the ground and several threaded columns cast into the lower end of the concrete pier. Each threaded column is threaded into a corresponding threaded hole in the steel arch frame section. A threaded sleeve is threaded to the upper end of each threaded column, and the threaded sleeve presses against the connecting end plate of the steel arch frame section, thus fixing the connecting end plate to the concrete pier. The threaded sleeve is at least 10 centimeters long, and the upper end of the threaded column extends beyond the threaded sleeve. This design improves the protective shed's resistance to lifting, making it less likely to be pulled off the ground.

[0012] Preferably, a vibration damping pad is laid on the concrete pier, the connecting end of the steel arch frame is pressed onto the vibration damping pad, and the threaded column passes through the vibration damping pad. This can improve the protective energy dissipation effect.

[0013] Preferably, an isolation sleeve is provided between the threaded sleeve and the connecting end plate of the steel arch frame, and the isolation sleeve is fitted onto the threaded post. When the threads between the threaded sleeve and the threaded post are damaged, a new threaded sleeve is replaced and connected to the undamaged threads of the threaded post. The isolation sleeve isolates the threaded sleeve from the connecting end of the steel arch frame, allowing the upper part to be pressed against the end plate of the steel arch frame. This facilitates convenient repair and reuse after damage.

[0014] Preferably, the lower end of the threaded post is provided with several gripping bars, the extension direction of which intersects the extension direction of the threaded post. This makes it difficult for the threaded post to be pulled out of the concrete pier.

[0015] Preferably, the grip bar and the threaded post are connected together by an arc-shaped connecting section, with both the grip bar and the threaded post tangent to the arc-shaped connecting section. This reduces stress concentration that could lead to breakage of the grip bar.

[0016] Preferably, the concrete pier has several annular grooves on its circumference, distributed vertically and extending circumferentially, with soil from below filling the grooves. This makes the concrete pier more difficult to pull out.

[0017] Preferably, the bottom surface of the concrete pier is provided with inserts that are inserted into the soil, and the inserts are inclined. This makes the concrete pier difficult to pull out.

[0018] The present invention has the following beneficial effects: it can minimize the interference to the surrounding environment when constructing tunnels by blasting. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the protective canopy and vibration damping structure in use. The rear and front explosion-proof curtains are not shown in the diagram. Figure 2 yes Figure 1 A magnified view of a portion of point A; Figure 3 This is a three-dimensional structural diagram of the protective shed; Figure 4 This is a diagram showing the protective canopy after the rubber sheeting has been removed; Figure 5 yes Figure 4 A magnified view of the area; Figure 6 This is a schematic diagram showing the connection between the steel arch frame and the ground.

[0020] In the diagram: 1. Protective shed; 2. Mountain body for tunnel construction; 3. Vibration damping trench; 4. Area enclosed by the vibration damping trench; 5. Rear gantry; 6. Arched shed; 7. Front gantry; 8. Arched inner frame; 9. Arched steel mesh; 10. Rubber sheet; 11. Steel arch frame; 12. Bolt holes in the steel arch frame; 60. Connecting end plate in the steel arch frame; 13. Ground; 14. Concrete pier; 15. Threaded column; 16. Threaded sleeve; 17. Vibration damping pad; 18. Isolation sleeve; 19. Ground grip bar; 20. Arc-shaped connecting section; 21. Circular ditch. 22. Insert pin; 23. Left steel column; 24. Right steel column; 25. Horizontal steel bar; 26. Left diagonal support; 27. Right diagonal support; 28. Horizontal support; 29. ​​Vertical support; 30. Bolt holes for the gantry section; 31. Connecting end plate for the gantry section; 32. First vertical vibration damping ring; 33. Second vertical vibration damping ring; 34. Vertical vibration damping cover; 35. Outer vertical compression ring of the first vertical vibration damping ring section; 36. Inner vertical compression ring of the first vertical vibration damping ring section; 37. Annular vibration damping plate of the first vertical vibration damping ring section; 1 The following components are listed: the inner circumferential surface 38 of the outer vertical compression ring of the first vertical vibration damping ring section; the outer circumferential surface 39 of the inner vertical compression ring of the first vertical vibration damping ring section; the damping spring 40 of the first vertical vibration damping ring section; the inner flange 41 of the first vertical vibration damping ring section; the outer vertical compression ring 42 of the second vertical vibration damping ring section; the inner vertical compression ring 43 of the second vertical vibration damping ring section; the annular damping plate 44 of the second vertical vibration damping ring section; and the inner circumferential surface 45 of the outer vertical compression ring of the second vertical vibration damping ring section. The following components are included: outer circumferential surface of the compression ring 46, damping spring of the second vertical vibration damping ring 47, inner flange of the second vertical vibration damping ring 48, vibration damping groove 49, inner cover plate 50, outer cover plate 51, first push rod 52, first pull rod 53, second pull rod 54, conical energy dissipation head 55, outer shell 56, explosive charge of the first vertical vibration damping ring 57, explosive charge of the second vertical vibration damping ring 58, tunnel 59, vibration damping structure 61, first steel arch 62, and last steel arch 63. Detailed Implementation

[0021] The present invention will now be described in conjunction with the accompanying drawings and specific embodiments, wherein the anchor rod is inclined with one end higher than the other end, which is connected to the inner retaining wall, and the lower end of the anchor rod is lower than the bottom of the inner pit.

[0022] See Figures 1 to 6A method for on-site construction with blasting protection: A) Construct a protective shed 1 aligned with the tunnel entrance in the area of ​​the mountain where the tunnel is located; B) Begin tunnel excavation 59: B1) Cut away the perimeter of the tunnel construction area on one side of the mountain 2 where the tunnel is to be constructed to form a vibration damping groove 3 extending along the tunnel outline. The wall of the vibration damping groove on the side of the tunnel center is a stepped surface with two steps; B2) Construct a vibration damping structure 61 at the tunnel excavation end; B3) Blast the area 4 enclosed by the vibration damping groove, transport the blasted rock outside the tunnel, thereby completing the excavation of a section of the tunnel. Repeat steps B1 to B3 until the tunnel is completed. The protective shed includes a rear gantry 5 connected to the tunnel entrance, an arched shed 6 connected to the rear end of the rear gantry, and a front gantry 7 connected to the front end of the arched shed. The arched shed includes an inner arched frame 8, an arched steel mesh 9 supported on the inner arched frame, and a rubber sheet 10 covering the steel mesh. The arched steel mesh is composed of crisscrossing steel bars connected together. The arched inner frame includes nine steel arch frames 11 distributed along the tunnel depth direction. Each end of the steel arch frame has a connecting end plate 60 with bolt holes 12. The connecting end plate is made of steel. The connecting end plate is fixed to the ground 13 by a fixing structure. The fixing structure includes a concrete pier 14 cast into the ground and several threaded columns 15 cast into the lower end of the concrete pier. The threaded columns are threaded into the threaded holes of the steel arch frames, and the upper end of each threaded column is threadedly connected to a threaded sleeve 16. The threaded sleeve presses against the connecting end plate, fixing the connecting end plate to the concrete pier. The threaded sleeve is at least 10 cm long. The upper end of the threaded column extends beyond the threaded sleeve. A vibration damping pad 17 is laid on the concrete pier, and the connecting end of the steel arch frame is pressed against the vibration damping pad, with the threaded columns passing through it. An isolation sleeve 18 is provided between the threaded sleeve and the connecting end plate of the steel arch frame, and the isolation sleeve is fitted onto the threaded column. Several gripping bars 19 are provided at the lower end of the threaded column, with the extension direction of the gripping bars intersecting the extension direction of the threaded column. The gripping bars and the threaded column are connected together by an arc-shaped connecting section 20, with the gripping bars and the threaded column tangent to the arc-shaped connecting section. Several annular grooves 21 are provided on the circumference of the concrete pier, distributed vertically and extending circumferentially along the concrete pier, with the soil below ground filling the annular grooves. Inserts 22, inserted into the soil, are provided on the bottom surface of the concrete pier, with the inserts set at an angle. When the arched inner frame is connected to the tunnel entrance, the entire tunnel entrance is located within the space enclosed by the arched canopy. The first steel arch frame 62 is connected to the front gantry, and the last steel arch frame 63 is connected to the rear gantry. The front gantry is equipped with a front explosion-proof curtain that encloses the front end of the arched inner frame. The front explosion-proof curtain is connected to the front mast only at its upper end, and the rear mast has a rear explosion-proof curtain that closes the rear end of the arched inner frame. The rear explosion-proof curtain is connected to the rear mast only at its upper end.The front and rear gantry frames have the same structure. The front gantry includes a left steel column 23, a right steel column 24, horizontal steel bars 25 connected to the upper ends of the left and right steel columns, a left diagonal support 26 connecting the left steel column to the horizontal steel bars, a right diagonal support 27 connecting the right steel column to the horizontal steel bars, several horizontal supports 28 connecting the left steel column to the first steel arch frame, and a vertical support 29 connecting the horizontal steel bars to the first steel arch frame. The front explosion-proof curtain is connected to the horizontal steel bars. The left diagonal support, horizontal supports, right diagonal support, and vertical support are all steel structures. The lower ends of the left and right steel columns are provided with gantry connection end plates 31 with gantry bolt holes 30, and the gantry connection end is a steel structure.

[0023] The vibration damping structure includes a first vertical vibration damping ring 32, a second vertical vibration damping ring 33, and a vertical vibration damping cover 34. The specific process in section B2 involves installing the first vertical vibration damping ring on a step at the bottom of the vibration damping groove, extending the first vertical vibration damping ring along the extension direction of the vibration damping groove. The second vertical vibration damping ring is installed on another step, extending the second vertical vibration damping ring along the extension direction of the vibration damping groove. The vertical vibration damping cover covers the area enclosed by the vibration damping groove. The first vertical vibration damping ring comprises first vertical vibration damping rings nested together sequentially. The ring consists of an outer vertical compression ring 35, an inner vertical compression ring 36, and an annular damping plate 37. The inner circumferential surface 38 of the outer vertical compression ring of the first vertical damping ring is an inclined surface that slopes towards the direction of the vertical damping cover, and the outer circumferential surface 39 of the inner vertical compression ring of the first vertical damping ring is an inclined surface that slopes away from the direction of the vertical damping cover. The inner circumferential surface of the outer vertical compression ring of the first vertical damping ring abuts against the outer circumferential surface of the inner vertical compression ring of the first vertical damping ring. The first vertical vibration damping ring section's annular damping plate is connected to the first vertical vibration damping ring section's inner vertical compression ring via several first vertical vibration damping ring section damping springs 40. The inner vertical compression ring of the first vertical vibration damping ring section has an inner flange 41 facing the vertical vibration damping cover. The second vertical vibration damping ring includes a second vertical vibration damping ring section outer vertical compression ring 42, a second vertical vibration damping ring section inner vertical compression ring 43, and a second vertical vibration damping ring section's annular damping plate 44, which are sequentially nested together. The inner circumferential surface 45 of the second vertical vibration damping ring section's outer vertical compression ring is an inclined surface oriented towards the direction of the vertical vibration damping cover, and the outer circumferential surface 46 of the second vertical vibration damping ring section's inner vertical compression ring is an inclined surface oriented away from the direction of the vertical vibration damping cover. The inner circumferential surface of the second vertical vibration damping ring section's outer vertical compression ring abuts against the outer circumferential surfaces of the second vertical vibration damping ring section's outer and inner vertical compression rings. The second vertical vibration damping ring section's annular damping plate... Several damping springs 47 of the second vertical damping ring are connected to the inner vertical compression ring of the second vertical damping ring. The inner vertical compression ring of the second vertical damping ring is provided with an inner flange 48 of the second vertical damping ring facing the vertical damping cover. The outer vertical compression ring of the second vertical damping ring is located inside the space enclosed by the projection of the annular damping plate of the first vertical damping ring along the center line of the first vertical damping ring. The outer vertical compression ring of the second vertical damping ring and the wall of the tunnel form a damping groove 49. The vertical damping cover includes an inner cover plate 50 and an outer cover plate 51. The inner cover plate is connected to the inner flange of the first vertical damping ring through a first push rod 52. The inner cover plate abuts against the inner flange of the second vertical damping ring. The outer cover plate is connected to the outer vertical compression ring of the first vertical damping ring through a first pull rod 53 and to the outer vertical compression ring of the second vertical damping ring through a second pull rod 54. The outer cover plate has several energy dissipation holes, and the inner cover plate has conical energy dissipation heads 55 that are inserted into the corresponding energy dissipation holes. The diameter of the conical energy dissipation head at the end away from the outer cover plate is larger than the diameter of the energy dissipation hole. The outer cover plate is supported on the conical energy dissipation heads and connected to the inner cover plate.A conical energy dissipation head is fitted with an outer shell 56, the hardness of which is lower than that of the outer cover plate. A friction layer is provided on the surface of the conical energy dissipation head. An explosive charge 57 for the first vertical vibration damping ring is located on the outer circumference of the outer vertical compression ring of the first vertical vibration damping ring. The force generated when the explosive charge detonates drives the outer vertical compression ring of the first vertical vibration damping ring to move away from the vertical vibration damping cover and towards the tunnel center. An explosive charge 58 for the second vertical vibration damping ring is located on the outer circumference of the outer vertical compression ring of the second vertical vibration damping ring. The force generated when the explosive charge detonates drives the outer vertical compression ring of the first vertical vibration damping ring to move away from the vertical vibration damping cover and towards the tunnel center. In section B3, the explosive charge for the first and second vertical vibration damping rings is detonated simultaneously with the blasting of the portion located within the space enclosed by the vibration damping groove.

Claims

1. A method for constructing a tunnel with blasting protection, characterized in that, A. Construct a protective shed aligned with the tunnel entrance in the area of ​​the mountain where the tunnel is located; B. Begin excavating the tunnel: B1. Cut off the perimeter of the tunnel construction area on one side of the mountain where the tunnel is to be built to form a vibration damping groove extending along the tunnel outline. The wall of the vibration damping groove on the side of the tunnel center is a stepped surface with two steps. B2. Construct vibration damping structures at the excavation end of the tunnel; B3: Blasting is performed on the area enclosed by the vibration damping groove, and the blasted rock is transported outside the tunnel, thus completing the excavation of a section of the tunnel. Steps B1 to B3 are repeated until the tunnel is completed. The protective canopy includes a rear gantry that connects to the tunnel entrance, an arched canopy connected to the rear end of the rear gantry, and a front gantry connected to the front end of the arched canopy. The arched canopy includes an inner arched frame, an arched steel mesh supported on the inner arched frame, and a rubber sheet covering the steel mesh. The inner arched frame includes several steel arches distributed along the tunnel depth direction. The two ends of the steel arches are provided with bolt holes for the steel arches. The arch frame connecting end plate is a steel structure and is fixed to the ground by a fixing structure. All tunnel entrances are located within the space enclosed by the arched canopy. The first steel arch frame is connected to the front gantry, and the last steel arch frame is connected to the rear gantry. The front gantry is equipped with a front explosion-proof curtain that encloses the front end of the inner arch frame; the front explosion-proof curtain is only connected to the front gantry at its upper end. The rear gantry is equipped with a rear explosion-proof curtain that encloses the rear end of the inner arch frame; the rear explosion-proof curtain is only connected to the rear gantry at its upper end. The vibration damping structure includes a first vertical vibration damping ring, a second... The specific process in section B2 involving vertical vibration damping rings and vertical vibration damping covers is as follows: A first vertical vibration damping ring is installed on the step located at the bottom of the vibration damping groove, extending along the extension direction of the groove. A second vertical vibration damping ring is installed on another step, also extending along the extension direction of the groove. The vertical vibration damping cover covers the area enclosed by the groove. The first vertical vibration damping ring comprises, sequentially, an outer vertical compression ring, an inner vertical compression ring, and an annular vibration damping plate. The inner circumferential surface of the pressure ring is an inclined surface that slopes towards the direction of the vertical vibration damping cover. The outer circumferential surface of the vertical compression ring inside the first vertical vibration damping ring is an inclined surface that slopes away from the direction of the vertical vibration damping cover. The inner circumferential surface of the outer vertical compression ring of the first vertical vibration damping ring is in contact with the outer circumferential surface of the inner vertical compression ring of the first vertical vibration damping ring. The annular vibration damping plate of the first vertical vibration damping ring is connected to the inner vertical compression ring of the first vertical vibration damping ring through several damping springs of the first vertical vibration damping ring. The inner flange of the first vertical vibration damping ring is provided at the end of the inner vertical compression ring of the first vertical vibration damping ring facing the vertical vibration damping cover.The second vertical vibration damping ring includes an outer vertical compression ring, an inner vertical compression ring, and an annular damping plate of the second vertical vibration damping ring, all nested together in sequence. The inner circumferential surface of the outer vertical compression ring is an inclined surface oriented towards the direction of the vertical damping cover, while the outer circumferential surface of the inner vertical compression ring is an inclined surface oriented away from the direction of the vertical damping cover. The inner circumferential surface of the outer vertical compression ring abuts against the outer circumferential surfaces of the inner and outer vertical compression rings. The annular damping plate of the second vertical vibration damping ring is connected to the inner vertical compression ring of the second vertical vibration damping ring via several damping springs. The end of the ring facing the vertical vibration damping cover has a second vertical vibration damping ring inner flange. The outer vertical compression ring of the second vertical vibration damping ring is located inside the space enclosed by the projection of the annular vibration damping plate of the first vertical vibration damping ring along the center line of the first vertical vibration damping ring. A vibration damping groove is formed between the outer vertical compression ring of the second vertical vibration damping ring and the tunnel wall. The vertical vibration damping cover includes an inner cover plate and an outer cover plate. The inner cover plate is connected to the inner flange of the first vertical vibration damping ring through a first push rod, and the inner cover plate abuts against the inner flange of the second vertical vibration damping ring. The outer cover plate is connected to the outer vertical compression ring of the first vertical vibration damping ring through a first pull rod and to the outer vertical compression ring of the second vertical vibration damping ring through a second pull rod.

2. The method for constructing a blast-protected tunnel according to claim 1, characterized in that, The outer cover plate is provided with a plurality of energy dissipation through holes, and the inner cover plate is provided with conical energy dissipation heads that are correspondingly inserted into the energy dissipation through holes. The diameter of the conical energy dissipation head at the end away from the outer cover plate is larger than the diameter of the energy dissipation through holes. The outer cover plate is supported on the conical energy dissipation head and connected to the inner cover plate.

3. The method for constructing a blast-protected tunnel according to claim 2, characterized in that, The conical energy dissipation head is fitted with an outer shell, the hardness of which is lower than that of the outer cover plate.

4. A method for constructing a blast-protected tunnel according to claim 2 or 3, characterized in that, The surface of the conical energy dissipation head is provided with a friction layer.

5. A method for constructing a blast-protected tunnel according to claim 1, 2, or 3, characterized in that, The first vertical vibration damping ring is provided with an explosive charge on the outer circumferential surface of the outer vertical compression ring. When the explosive charge of the first vertical vibration damping ring explodes, the force generated drives the outer vertical compression ring of the first vertical vibration damping ring to move away from the location of the vertical vibration damping cover and towards the center of the tunnel. The second vertical vibration damping ring is provided with an explosive charge on the outer circumferential surface of the outer vertical compression ring of the second vertical vibration damping ring. When the explosive charge of the second vertical vibration damping ring explodes, the force generated drives the outer vertical compression ring of the first vertical vibration damping ring to move away from the location of the vertical vibration damping cover and towards the center of the tunnel. In B3, the first and second explosive charges of the first vertical vibration damping ring are detonated simultaneously when the portion located within the space enclosed by the vibration damping groove is blasted.

6. The method for constructing a blast-protected tunnel according to claim 1, characterized in that, The front and rear masts have the same structure. The front mast includes a left steel column, a right steel column, horizontal steel bars connected to the upper ends of the left and right steel columns, a left diagonal support connecting the left steel column to the horizontal steel bars, a right diagonal support connecting the right steel column to the horizontal steel bars, several horizontal supports connecting the left steel column to the first steel arch, and a vertical support connecting the horizontal steel bars to the first steel arch. The front explosion-proof curtain is connected to the horizontal steel bars. The left diagonal support, horizontal support, right diagonal support, and vertical support are all steel structures.

7. A method for constructing a blast-protected tunnel according to claim 6, characterized in that, The lower ends of both the left and right steel columns are provided with gantry section connecting end plates with bolt holes for the gantry section, and the gantry section connecting end plates are steel structures.

8. The method for constructing a blast-protected tunnel according to claim 7, characterized in that, The connecting end plate of the gantry section is fixed to the ground by a fixing structure. The fixing structure includes a concrete pier cast in the ground and a number of threaded columns cast in the concrete pier at the lower end. The threaded columns are inserted into the threaded holes of the steel arch frame section one by one. The upper end of the threaded column is threadedly connected to a threaded sleeve. The threaded sleeve is pressed against the connecting end plate of the steel arch frame section, thereby fixing the connecting end plate of the steel arch frame section to the concrete pier. The length of the threaded sleeve is more than 10 centimeters, and the upper end of the threaded column extends out of the threaded sleeve.

9. A method for constructing a blast-protected tunnel according to claim 8, characterized in that, The concrete pier is covered with a vibration damping pad, the connecting end of the steel arch frame is pressed on the vibration damping pad, and the threaded column passes through the vibration damping pad.

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