Water-rich soft rock tunnel close-range undercrossing adit controlled blasting structure and construction method thereof

Abstract

The invention relates to a water-rich soft rock tunnel close-range undercrossing adit controlled blasting structure and a construction method thereof, and the construction method comprises the steps of existing line assembly type temporary supporting, full-section primary drilling, lower section underholing area blasting, upper section blasting, steel arch frame installation, temporary supporting and the like, and the existing line assembly type temporary supporting adopts the assembly type temporary supporting to reinforce the adit; a movable excavation rack is adopted for full-section primary drilling for full-section drilling, the movable excavation rack is provided with a telescopic construction platform and adapts to tunnel faces with different widths, a rope saw slotting machine is adopted for slotting in a lower section slotting area for manufacturing a free face, a low-layer movable excavation rack is adopted for charging and then blasting in an upper section blasting process, and the movable excavation rack is provided with a telescopic construction platform and adapts to tunnel faces with different widths. The steel arch frame is finely adjusted and positioned through an adjustable supporting column, the steel arch frame is accurately installed, and a temporary support adopts a temporary support and a temporary inverted arch to form a stable system. The method has the advantages that the construction efficiency is high, the supporting effect is good, the existing line is stable, and the steel arch is not prone to deformation.

Description

Technical Field

[0001] The invention relates to the field of bridges, and in particular to a controlled blasting structure for a water-rich soft rock tunnel passing through a flat tunnel at a short distance and a construction method thereof. Background Art

[0002] When tunneling in complex soft rock geological conditions, if the blasting is not done carefully, it will cause cracks and damage to nearby buildings (structures), and in severe cases, it will cause tunnel collapse or large deformation. Especially when passing under existing lines, the construction of new tunnels is often limited to traditional blasting excavation, and vibration reduction measures need to be taken to control the blasting. The three-step blasting method has low construction efficiency, and more suitable blasting methods should be used for soft rocks with good self-stability. In addition, tunnel support is also a very important step that affects the safety and stability of tunnel excavation. Therefore, for tunnel blasting construction in water-rich soft rock environments, especially how to control the settlement of the flat tunnel and ensure the stability of the tunnel when passing under existing lines, it is urgent to find efficient construction methods to solve current technical problems. Summary of the invention

[0003] The purpose of the present invention is to solve the above problems existing in the prior art and provide a controlled blasting structure and a construction method for a water-rich soft rock tunnel with a close-range horizontal tunnel.

[0004] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme: The construction method of a water-rich soft rock tunnel with a close-range horizontal tunnel controlled blasting structure comprises the following steps:

[0005] Step 1: Temporary support for existing lines

[0006] Before blasting, install a temporary fabricated support on the existing line. First, install and fix the temporary steel arch frame on the existing line through anchor rods, and then install the temporary tic-tac-toe steel frame.

[0007] During installation, first install the temporary vertical support on the temporary steel arch frame, use pads for temporary support at the bottom, then install the temporary middle cross brace, and finally remove the pads;

[0008] Connect the temporary vertical support and temporary bottom cross brace with bolts, and install the temporary bottom cross brace on the temporary steel arch frame to complete the advance support;

[0009] Step 2: Drilling the entire section at one time

[0010] After the advanced support is completed, the whole section is drilled at one time. The mobile excavation platform is assembled first. After the platform is assembled as a whole, it is moved to the tunnel face. The construction platforms on both sides are adjusted according to the width of the tunnel face. Then the mobile excavation platform is used to drill holes in the blasting areas of the upper and lower sections at the same time.

[0011] Step 3: Blasting of the lower section trenching area

[0012] Detonate in the order of cut hole → auxiliary hole → peripheral hole;

[0013] In the lower section, wedge-shaped grooves without clamps are used for cutting. The cutting size is determined according to the design requirements. The free surface is manufactured by a rope saw groover. After the rope saw grooves are cut, holes are drilled and charged. Digital electronic detonators are used for shock-absorbing blasting.

[0014] Step 4: Upper section blasting

[0015] After the blasted ballast pile of the lower section is simply leveled, the upper gantry frame of the mobile excavation platform is dismantled to form a low-level mobile excavation platform, which is then moved to the upper section for charging. The blast holes of the upper section are detonated in the order of auxiliary holes → inner circle holes → peripheral holes.

[0016] Step 5: Steel arch installation

[0017] After the blasting is completed, the slag of the upper and lower sections is transported out of the tunnel, and then the initial support of the entire tunnel section is carried out. The steel arch frame is assembled on the ground, and the steel arch frame support is installed using adjustable support columns;

[0018] The adjustable support columns are symmetrically arranged on both sides of the steel arch frame. The top support of the adjustable support columns is aligned with the steel arch frame, and the whole is lifted upward. Then, fine-tuning is performed through a small electric hydraulic jack to complete the precise installation of the steel arch frame.

[0019] Step 6: Temporary support

[0020] After the steel arch frame is completed, temporary reinforcement is carried out first, using the temporary invert to form a temporary closed loop. At the same time, temporary supports are added between the initial steel arch frame and the temporary invert to form a stable system, and then construction continues.

[0021] Specifically, in step 1, the temporary cross-shaped steel frame is composed of a temporary vertical support, a temporary middle cross brace, a temporary bottom cross brace and a plurality of joints;

[0022] Bolt connection joints are used on both sides of the upper and lower middle parts of the temporary vertical support. The joints are welded by three steel plates to form a U-shaped notch, and then bolted to the temporary middle cross brace respectively;

[0023] A steel plate is welded at the bottom of the temporary vertical support, and then the steel plate and the temporary bottom cross brace are connected with the first high-strength bolts to fix the temporary vertical support on the temporary bottom cross brace;

[0024] Arc-shaped connecting steel plates are welded to the supporting ends of the temporary cross-shaped steel frame, and then fixed to the temporary steel arch frame through the first high-strength bolt connection.

[0025] Specifically, in step 2, the mobile excavation stand is connected by bolts to form a whole, and the four columns and vertical support columns of the portal upper frame are connected with the cross beam and four corners of the portal lower frame by fastening with second high-strength bolts and reinforcing steel plates;

[0026] The portal lower frame is supported by beams and diagonal braces, and the bottom of the columns of the portal lower frame are installed with moving wheels in a threaded connection manner, which is convenient for installation and disassembly;

[0027] Several equally spaced steel pipes arranged vertically and horizontally are overlapped by clamps on the portal upper frame and portal lower frame. A dense mesh is set on the steel pipes to form a pedestrian passage. Additional passage fences are added, and temporary passage openings and stairs are set up to facilitate construction workers to walk up and down on each working surface.

[0028] Furthermore, in step 2, a plurality of rotating shafts are vertically arranged on the columns at the four corners of the upper and lower door frames, and the folding platform is connected to the rotating shafts in an articulated manner;

[0029] One end of the detachable diagonal brace is installed with a second high-strength bolt, and the other end is installed on the detachable buckle under the folding platform, and the detachable buckle is fixed to the folding platform by bolt connection;

[0030] When in use, the folding platform is turned over into a flat surface and then fixed with a detachable diagonal brace.

[0031] Furthermore, in step 2, a fixed fence is provided on the folding platform, and slide rails are installed in both the folding platform and the fixed fence. The retractable platform is arranged inside the folding platform and cooperates with the slide rails inside the folding platform, so that the working surface of the construction personnel is increased by extending the platform;

[0032] At the same time, a retractable fence is installed on the folding platform and cooperates with the slide rail on the fixed fence, and a pulley is set at the bottom of the retractable fence.

[0033] Furthermore, a number of equally spaced steel pipes arranged vertically and horizontally are overlapped on the portal upper frame and the portal lower frame by means of clamps, a dense mesh is arranged on the steel pipes to form a pedestrian passage, additional passage fences are provided, and temporary passage openings and stairs are set up to facilitate construction workers to walk up and down on each working surface.

[0034] Specifically, in step three, the rope saw slotting machine is constructed using a rope saw slotting operating platform, which is mainly composed of a base, a variable height rod, a ground nail, a panel, and solid round steel. Ground nails are set at the four corners of the base, and the rope saw slotting operating platform is fixed to the ground through the ground nails. The variable height rod is set above the base, and multiple rows of grooves are set on the variable height rod;

[0035] The solid round steel is embedded in the panel. Select a suitable height and place the solid round steel extending out of the panel into the groove.

[0036] Specifically, in step five, the adjustable support column is divided into an upper support body and a lower support body. The upper end of the upper support body is bolted to the top support, and the lower end is welded to the upper support plate. The upper end of the lower support body is welded to the lower support plate, and the lower end is welded to the bottom plate. Telescopic rods are arranged at the four corners between the upper support plate and the lower support plate, and a small electric hydraulic jack is arranged in the middle. At the same time, the telescopic rods at the four corners are connected with connecting plates to increase stability.

[0037] Furthermore, in step five, the top support is composed of an arc-shaped support top and thickened straight piece angle codes, four thickened straight piece angle codes are welded to the arc-shaped support top, and then the bolt holes on the angle codes are aligned with the bolt holes on the middle plate, and then fastened by bolts; the top support can change the inclination angle of the top support through the angle adjustment between the U-shaped joint and the thickened straight piece angle codes so as to fit the steel arch frame.

[0038] Preferably, the arc-shaped supporting top can be processed and customized according to the curvature of the steel arch frame, so as to facilitate replacement and reuse.

[0039] Furthermore, a ground nail hole is set on the bottom plate, and after the steel arch frame installation adjustment device is placed at the designated position, the anchor nail is aligned with the ground nail hole and driven in. A pull ring is welded on the anchor nail, and after the steel arch frame is installed, a crowbar is used to push the pull ring to pry out the anchor nail.

[0040] Specifically, in step six, the added temporary support includes oblique supports on both sides and a vertical support in the middle, wherein the Y-shaped support member and the T-shaped support member are respectively connected to the support steel with flanges to form an oblique support and a vertical support;

[0041] The Y-shaped support member, the T-shaped support member and the arc-shaped support steels on both sides are connected by flanges to form a temporary invert;

[0042] Arc-shaped connecting steel plates are welded to the ends of the temporary support and the temporary invert respectively, and then the arc-shaped connecting steel plates are installed on the steel arch frame by means of a third high-strength bolt.

[0043] The controlled blasting structure for a water-rich soft rock tunnel with a close-range underpass of a flat tunnel is manufactured by using the construction method for the controlled blasting structure for a water-rich soft rock tunnel with a close-range underpass of a flat tunnel.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present invention uses assembled temporary supports to reinforce existing lines. Through on-site assembly and bolt connection, a large amount of welding and other work is not required, which speeds up the construction efficiency and ensures the safety of existing lines.

[0046] 2. The present invention adopts a reverse blasting construction method, first blasting the lower section and then blasting the upper section, and at the same time adopts a rope saw groove cutting method to increase the free surface of the groove cutting area, thereby ensuring the smooth progress of the blasting and speeding up the excavation work.

[0047] 3. The present invention adopts a mobile excavation stand, through the combined use of a portal upper frame and a portal lower frame, and a retractable construction platform, to adapt to the drilling and charging of tunnel faces of different heights and widths.

[0048] 4. The present invention adopts temporary inverted arches and supports as temporary supports, which are installed on the steel arch frame to form a temporary closed loop, thereby effectively enhancing the stability of the steel arch frame.

[0049] 5. The present invention adopts adjustable support columns to integrally install the steel arch frame, and uses a small electric hydraulic jack to fine-tune the steel arch frame, thereby improving the accuracy of the steel arch frame installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is the erection diagram of the existing flat tunnel assembled temporary support;

[0051] Figure 2 It is an elevation view of the mobile excavation gantry;

[0052] Figure 3 It is the enlarged view of A;

[0053] Figure 4 It is a telescopic structure diagram of the construction platform;

[0054] Figure 5 This is a plan view of the layout of the wire saw groove cutting;

[0055] Figure 6 This is a schematic diagram of blasting excavation of the upper section;

[0056] Figure 7 It is a three-dimensional diagram of an adjustable support column;

[0057] Figure 8 This is the top support installation structure diagram;

[0058] Fig. 9 It is the elevation drawing of the steel arch mounting adjustment device;

[0059] Fig.10 It is a temporary reinforcement support elevation drawing.

[0060] In the figure, 1. Temporary cross steel frame; 2. Temporary vertical support; 3. Temporary middle cross brace; 4. Temporary bottom cross brace; 5. Temporary steel arch frame; 6. Joint; 7. Arc-shaped connecting steel plate; 8. First high-strength bolt; 9. Steel plate; 10. Door-type upper frame; 11. Vertical support column; 12. Second high-strength bolt; 13. Reinforcement steel plate; 14. Door-type lower frame; 15. Moving wheel; 16. Fixed fence; 17. Retractable fence; 18. Retractable platform; 19. Folding platform; 20. Slide rail; 21. Removable diagonal brace; 22. Rotating shaft; 23. Diagonal brace; 24. Crossbeam; 25. Passage fence; 26. Pedestrian passage; 27. Stairs; 28. Removable buckle; 29. ​​Rope saw slotting machine; 30. Rope saw slotting operation platform; 31. Solid round steel; 32. Variable height rod; 33. Groove; 34. Panel; 35. Base; 3 6. Ground nails; 37. Low-rise mobile excavation gantry; 38. Ballast pile; 39. Top support; 40. Upper support; 41. Lower support; 42. Upper support plate; 43. Lower support plate; 44. Telescopic rod; 45. Small electric hydraulic jack; 46. Connecting plate; 47. Bottom plate; 48. Arc top support; 49. Thickened straight piece angle code; 50. Middle plate; 51. Steel arch frame; 52. Temporary support; 53. Oblique support ; 54. Vertical support; 55. Y-shaped support member; 56. T-shaped support member; 57. Temporary invert; 58. Support steel; 59. Arc-shaped support steel; 60. Flange; 61. Arc-shaped connecting steel plate; 62. Adjustable support column; 63. U-shaped joint; 64. Fixed plate; 65. Limiting plate; 66. Second bolt; 67. Anchor nail; 68. Pull ring; 69. Ground nail hole; 70. First bolt. DETAILED DESCRIPTION

[0061] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0062] Those skilled in the art should understand that, in the disclosure of the present invention, the orientation or position relationship indicated by terms such as "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0063] Example 1

[0064] like Figure 1-10As shown, the construction method of the controlled blasting structure of a water-rich soft rock tunnel under a horizontal tunnel at a close distance includes the following steps:

[0065] Step 1: Temporary support for existing lines

[0066] Before blasting, install assembled temporary supports on the existing line. First, install and fix the temporary steel arch frame 5 on the existing line through anchor rods, and then install the temporary cross steel frame 1. During installation, first install the temporary vertical support 2 on the temporary steel arch frame 5, and use pads for temporary support at the bottom, and then install the temporary middle cross brace 3. Finally, remove the pads, connect the temporary vertical support 2 and the temporary bottom cross brace 4 through the first high-strength bolts 8, and install the temporary bottom cross brace 4 on the temporary steel arch frame 5 at the same time.

[0067] Specifically, the temporary cross steel frame 1 is composed of a temporary vertical support 2, a temporary middle cross brace 3, a temporary bottom cross brace 4 and a plurality of joints 6. The first high-strength bolts 8 are respectively used to connect the joints 6 on both sides of the middle upper part and the middle lower part of the temporary vertical support 2. The joints 6 are welded by three steel plates 9 to form a U-shaped notch, and then the first high-strength bolts 8 are respectively used to connect the temporary middle cross brace 3.

[0068] Furthermore, a steel plate 9 is welded to the bottom of the temporary vertical support 2 , and then the steel plate 9 and the temporary bottom cross brace 4 are connected by a first high-strength bolt 8 , so that the temporary vertical support 2 is fixed to the temporary bottom cross brace 4 .

[0069] Among them, arc-shaped connecting steel plates 7 are welded to each supporting end of the temporary cross steel frame 1, and then connected and fixed to the temporary steel arch frame 5 by the first high-strength bolts 8.

[0070] Step 2: Drilling the entire section at one time

[0071] After completing the advance support, the entire section will be drilled at one time. First, assemble the mobile excavation gantry. After the gantry is assembled as a whole, move it to the face. Adjust the construction platforms on both sides according to the width of the face, and then use the mobile excavation gantry to drill holes in the upper and lower section blasting areas at the same time.

[0072] Specifically, the mobile excavation rig can perform full-section one-time drilling and half-section charging. The portal upper frame 10 and the portal lower frame 14 are connected as a whole by bolts, and the four columns and vertical support columns 11 of the portal upper frame 10 are connected to the cross beam and four corners of the portal lower frame 14 by fastening with second high-strength bolts 12 and reinforcing steel plates 13. Since the portal lower frame 14 is relatively high, it is supported by cross beams 24 and diagonal braces 23. The bottom of the columns of the portal lower frame 14 is installed with moving wheels 15 by threaded connection, which is convenient for installation and disassembly.

[0073] Specifically, a plurality of rotating shafts 22 are vertically arranged on the columns at the four corners of the upper and lower frames of the portal type, the folding platform 19 is connected to the rotating shafts 22 in an articulated manner, one end of the detachable diagonal brace 21 is installed with the second high-strength bolt 12, and the other end is installed on the detachable buckle 28 under the folding platform 19, and the detachable buckle 28 is fixed to the folding platform 19 in a bolted manner. When in use, the folding platform 19 is turned over into a plane, and then fixed with the detachable diagonal brace 21, which is convenient for movement and installation.

[0074] Among them, a fixed fence 16 is provided on the folding platform 19, and a slide rail 20 is installed in both the folding platform 19 and the fixed fence 16. The retractable platform 18 is arranged inside the folding platform 19 and cooperates with the slide rail 20 in the folding platform 19, so as to increase the working surface of the construction personnel by extending the platform;

[0075] At the same time, a retractable fence 17 is installed on the folding platform 19 and cooperates with the slide rail 20 on the fixed fence 16. A pulley is set at the bottom of the retractable fence 17.

[0076] Among them, a number of equally spaced steel pipes arranged vertically and horizontally are overlapped in the portal upper frame 10 and the portal lower frame 14 by means of clamps, a dense mesh is arranged on the steel pipes to form a pedestrian passage 26, a passage fence 25 is added, and a temporary passage opening and stairs 27 are set to facilitate construction workers to walk up and down on each working surface.

[0077] Step 3: Blasting of the lower section trenching area

[0078] Detonation is carried out in the order of slot hole → auxiliary hole → peripheral hole. In the slot area of ​​the lower section, wedge-shaped slotting without clamping is adopted, and the cutting is carried out by rope saw. The cutting size is determined according to the design requirements. The open face is manufactured by rope saw slotting machine 29. After the rope saw slotting, drilling and charging are carried out. With the help of digital electronic detonator, shock-absorbing blasting is realized to realize fine control.

[0079] Specifically, the wire saw slotting machine 29 uses a wire saw slotting operation platform 30 for convenient and stable construction, which is mainly composed of a base 35, a variable height rod 32, a ground nail 36, a panel 34, and a solid round steel 31. The four corners of the base 35 are provided with ground nails 36, and the wire saw slotting operation platform 30 is fixed to the ground through the ground nails 36. The variable height rod 32 is arranged above the base 35, and a plurality of rows of grooves 33 are arranged on the variable height rod 32. The solid round steel 31 is embedded in the panel 34, and the solid round steel 31 extending out of the panel is placed in the groove 33 at a suitable height.

[0080] Step 4: Upper section blasting

[0081] After simply leveling the slag pile 38 after blasting the lower section, the portal upper frame 10 of the mobile excavation stand is dismantled to form a low-level mobile excavation stand 37, which is then moved to the upper section for charging, and the blast holes in the upper section are detonated in the order of auxiliary eye → inner circle eye → peripheral eye.

[0082] Step 5: Steel arch installation

[0083] After the blasting is completed, the slag of the upper and lower sections is transported out of the tunnel, and then the initial support of the entire tunnel section is carried out. The steel arch frame 51 is assembled on the ground, and the steel arch frame 51 support is installed using adjustable support columns 62. The adjustable support columns 62 are symmetrically arranged on both sides of the steel arch frame 51, and the top support 39 of the adjustable support column 62 is aligned with the steel arch frame 51, and the whole is lifted upward, and then fine-tuned by a small electric hydraulic jack 45 to complete the precise installation of the steel arch frame 51.

[0084] Specifically, the adjustable support column 62 is divided into an upper support body 40 and a lower support body 41. The upper end of the upper support body 40 is bolted to the top support 39, and the lower end is welded to the upper support plate 42. The upper end of the lower support body 41 is welded to the lower support plate 43, and the lower end is welded to the bottom plate 47. Four parallel and symmetrical grooves are set at the four corners between the upper support plate 42 and the lower support plate 43 to place and install the telescopic rod 44, and a small electric hydraulic jack 45 is set in the middle. At the same time, the telescopic rods 44 at the four corners are connected with connecting plates 46 to increase stability.

[0085] The top support 39 is composed of an arc-shaped top support 48 and a thickened straight piece angle bracket 49. The bottom of the arc-shaped top support 48 is welded to a fixing plate 64 on a U-shaped joint 63. The thickened straight piece angle bracket 49 is inserted into two limiting plates 65 of the U-shaped joint 63 and then fixed with a second bolt 66. The thickened straight piece angle bracket 49 is aligned with the bolt hole on the middle plate 50 and then fixed with a first bolt 70.

[0086] It is worth mentioning that the arc-shaped top support 48 can be processed and customized according to the curvature of the steel arch frame 51, which is convenient for replacement and reuse. At the same time, the top support 39 can change the inclination angle of the top support 39 by adjusting the angle between the U-shaped joint 63 and the thickened straight piece angle code 49 so as to fit the steel arch frame 51.

[0087] Specifically, a ground nail hole 69 is provided on the bottom plate 47. After the steel arch frame installation adjustment device is placed at a designated position, the anchor nail 67 is aligned with the ground nail hole 69. A pull ring 68 is welded on the anchor nail 67. After the steel arch frame 51 is installed, the pull ring 68 is supported by a crowbar to pry out the anchor nail 67.

[0088] Step 6: Temporary support

[0089] After the steel arch frame 51 is completed, temporary reinforcement is first performed, and a temporary closed loop is formed using a temporary invert 57. At the same time, a temporary support 52 is added between the initial steel arch frame 51 and the temporary invert 57 to form a stable system, and then construction is continued.

[0090] Specifically, the added temporary support 52 includes oblique supports 53 on both sides, vertical supports 54 and temporary inverts 57, wherein the Y-shaped support member 55 and the T-shaped support member 56 are respectively connected to the support steel 58 by flanges 60 to form the oblique support 53 and the vertical support 54.

[0091] Among them, the Y-shaped support member 55, the T-shaped support member 56 and the arc-shaped support steels 59 on both sides are connected by flanges 60 to form a temporary invert 57.

[0092] Furthermore, arc-shaped connecting steel plates 61 are welded to the ends of the temporary support 52 and the temporary invert 57 respectively, and then the arc-shaped connecting steel plates 61 are installed on the steel arch frame 51 by third high-strength bolts.

[0093] Example 2

[0094] The controlled blasting structure for a water-rich soft rock tunnel with a close-range underpass horizontal tunnel is constructed by using the construction method for the controlled blasting structure for a water-rich soft rock tunnel with a close-range underpass horizontal tunnel of Example 1.

[0095] The parts not described in detail in the present invention are prior art, so the present invention does not describe them in detail.

[0096] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0097] Although this article uses more 1, temporary tic-tac-toe steel frame, 2, temporary vertical support, 3, temporary middle cross brace, 4, temporary bottom cross brace, 5, temporary steel arch frame, 6, joint, 7, arc-shaped connecting steel plate, 8, high-strength bolt, 9, steel plate, 10, portal upper frame, 11, vertical support column, 12, high-strength bolt, 13, reinforcing steel plate, 14, portal lower frame, 15, moving wheel, 16, fixed fence, 17, retractable fence, 18, retractable platform, 19, folding platform, 20, slide rail, 21, detachable diagonal brace, 22, rotating shaft, 23, diagonal brace, 24, crossbeam, 25, channel fence, 26, pedestrian walkway, 27, stairs, 28, detachable buckle, 29, rope saw grooving machine, 30, rope saw grooving operation platform, 31, solid round steel, 32, variable height rod, 33, groove, 34, panel, 35, base, 36, ground nail, 37, low-rise The following terms are used: mobile excavation platform 38, ballast pile 39, top support 40, upper support body 41, lower support body 42, upper support plate 43, lower support plate 44, telescopic rod 45, small electric hydraulic jack 46, connecting plate 47, bottom plate 48, arc-shaped top support 49, thickened straight plate angle code 50, middle plate 51, steel arch frame 52, temporary support 53, oblique support 54, vertical support 55, Y-shaped support member 56, T-shaped support member 57, temporary invert 58, support steel 59, arc-shaped support steel 60, flange 61, arc-shaped connecting steel plate 62, adjustable support column 63, U-shaped joint 64, fixing plate 65, limiting plate 66, second bolt 67, anchor nail 68, pull ring 69, ground nail hole 70, first bolt, etc., but the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present invention; any additional limitations interpreted as them are contrary to the spirit of the present invention.

[0098] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that are the same or similar to those of the present application fall within the protection scope of the present invention.

Claims

1. A construction method for a water-rich soft rock tunnel with a controlled blasting structure at a close distance through a flat tunnel, characterized in that: The following steps are involved: Step 1: Temporary support for existing lines Before blasting, a temporary assembled support is installed on the existing line. First, a temporary steel arch frame (5) is installed and fixed on the existing line by anchor rods, and then a temporary cross steel frame (1) is installed; During installation, first install the temporary vertical support (2) onto the temporary steel arch frame (5), use pads at the bottom for temporary support, then install the temporary middle cross support (3), and finally remove the pads; The temporary vertical support (2) and the temporary bottom cross brace (4) are connected by bolts, and the temporary bottom cross brace (4) is installed on the temporary steel arch frame (5) to complete the advance support; Step 2: Drilling the entire section at one time After the advanced support is completed, the whole section is drilled at one time. The mobile excavation platform is assembled first. After the platform is assembled as a whole, it is moved to the tunnel face. The construction platforms on both sides are adjusted according to the width of the tunnel face. Then the mobile excavation platform is used to drill holes in the blasting areas of the upper and lower sections at the same time. Step 3: Blasting of the lower section trenching area Detonate in the order of cut hole → auxiliary hole → peripheral hole; In the groove cutting area of ​​the lower section, a wedge-shaped groove cutting without clamping is adopted, and a rope saw is used for cutting. The cutting size is determined according to the design requirements. A rope saw groove cutting machine (29) is used to manufacture the free surface. After the rope saw groove cutting, holes are drilled and charged, and digital electronic detonators are used for shock-absorbing blasting. Step 4: Upper section blasting After the blasted slag pile (38) of the lower section is simply leveled, the portal upper frame (10) of the mobile excavation stand is dismantled to form a lower mobile excavation stand (37), which is then moved to the upper section for charging, and the blast holes of the upper section are detonated in sequence in the order of auxiliary hole → inner circle hole → peripheral hole; Step 5: Steel arch installation After the blasting is completed, the slag of the upper and lower sections is transported out of the tunnel, and then the initial support of the entire tunnel section is carried out. The steel arch frame (51) is assembled on the ground, and the steel arch frame (51) is supported by adjustable support columns (62) for installation; The adjustable support columns (62) are symmetrically arranged on both sides of the steel arch frame (51), and the top support (39) of the adjustable support columns (62) is aligned with the steel arch frame (51), and the whole is lifted upward, and then fine-tuned by a small electric hydraulic jack (45) to complete the accurate installation of the steel arch frame (51); Step 6: Temporary support After the steel arch frame (51) is completed, temporary reinforcement is first performed, and a temporary closed loop is formed by using a temporary inverted arch (57). At the same time, a temporary support (52) is added between the initial steel arch frame (51) and the temporary inverted arch (57) to form a stable system, and then construction is continued.

2. The construction method of the controlled blasting structure of a water-rich soft rock tunnel under a horizontal tunnel at a close distance according to claim 1 is characterized in that: In step 1, the temporary cross-shaped steel frame (1) is composed of a temporary vertical support (2), a temporary middle cross support (3), a temporary bottom cross support (4) and a plurality of joints (6); The upper and lower sides of the temporary vertical support (2) are respectively connected by bolts to joints (6), the joints (6) are welded by three steel plates (9) to form a U-shaped notch, and then are respectively bolted to the temporary middle cross brace (3); A steel plate (9) is welded to the bottom of the temporary vertical support (2), and then the steel plate (9) and the temporary bottom cross brace (4) are connected by a first high-strength bolt (8), so that the temporary vertical support (2) is fixed to the temporary bottom cross brace (4); Each supporting end of the temporary crisscross steel frame (1) is welded with an arc-shaped connecting steel plate (7), which is then connected and fixed to the temporary steel arch frame (5) via a first high-strength bolt (8).

3. The construction method of the controlled blasting structure of a water-rich soft rock tunnel under a horizontal hole at a close distance according to claim 1 is characterized in that: In step 2, the portal upper frame (10) and the portal lower frame (14) of the mobile excavation stand are connected by bolts to form a whole, and the four columns and vertical support columns (11) of the portal upper frame (10) are connected to the cross beam and four corners of the portal lower frame (14) by fastening with second high-strength bolts (12) and reinforcing with reinforcing steel plates (13); The portal lower frame (14) is supported by a crossbeam (24) and a diagonal brace (23), and a moving wheel (15) is installed at the bottom of the column of the portal lower frame (14) in a threaded connection manner, so as to facilitate installation and disassembly; A plurality of steel pipes arranged vertically and horizontally at equal intervals are overlapped by a hoop on a portal upper frame (10) and a portal lower frame (14), a dense mesh is arranged on the steel pipes to form a pedestrian passage (26), a passage fence (25) is added, and a temporary passage opening and stairs (27) are provided to facilitate construction workers to walk up and down on each working surface.

4. The construction method of the controlled blasting structure of a water-rich soft rock tunnel under a horizontal hole at a close distance according to claim 3 is characterized in that: In step 2, a plurality of rotating shafts (22) are vertically arranged on the columns at the four corners of the upper and lower door frames, and the folding platform (19) is connected to the rotating shafts (22) in an articulated manner; One end of the detachable diagonal brace (21) is mounted with a second high-strength bolt (12), and the other end is mounted on a detachable buckle (28) under the folding platform (19), and the detachable buckle (28) is fixed to the folding platform (19) in a bolted manner; When in use, the folding platform (19) is turned over to a flat surface and then fixed with a detachable diagonal brace (21).

5. The construction method of the controlled blasting structure of a water-rich soft rock tunnel under a horizontal hole at a close distance according to claim 4 is characterized in that: In step 2, a fixed fence (16) is provided on the folding platform (19), and slide rails (20) are installed in both the folding platform (19) and the fixed fence (16). The retractable platform (18) is arranged inside the folding platform (19) and cooperates with the slide rails (20) inside the folding platform (19), so as to increase the working surface of the construction personnel by extending the platform; At the same time, a retractable fence (17) is installed on the folding platform (19) and cooperates with a slide rail (20) on the fixed fence (16), and a pulley is arranged at the bottom of the retractable fence (17).

6. The construction method of a water-rich soft rock tunnel with a controlled blasting structure at a close distance under a flat hole according to claim 1 is characterized in that: In step 3, the rope saw slotting machine (29) is constructed using a rope saw slotting operating platform (30), wherein the rope saw slotting operating platform (30) is mainly composed of a base (35), a variable height rod (32), a ground nail (36), a panel (34), and a solid round steel (31). Ground nails (36) are arranged at four corners of the base (35), and the rope saw slotting operating platform (30) is fixed to the ground through the ground nails (36). The variable height rod (32) is arranged above the base (35), and a plurality of rows of grooves (33) are arranged on the variable height rod (32); The solid round steel (31) is embedded in the panel (34), and a suitable height is selected to place the solid round steel (31) extending out of the panel in the groove (33).

7. The construction method of a water-rich soft rock tunnel with a controlled blasting structure at a close distance through a flat hole according to claim 1 is characterized in that: In step five, the adjustable support column (62) is divided into an upper support body (40) and a lower support body (41). The upper end of the upper support body (40) is bolted to the top support (39), and the lower end is welded to the upper support plate (42). The upper end of the lower support body (41) is welded to the lower support plate (43), and the lower end is welded to the bottom plate (47). Telescopic rods (44) are arranged at the four corners between the upper support plate (42) and the lower support plate (43), and a small electric hydraulic jack (45) is arranged in the middle. At the same time, the telescopic rods (44) at the four corners are connected with connecting plates (46) to increase stability.

8. The construction method of a water-rich soft rock tunnel with a controlled blasting structure at a close distance through a flat hole according to claim 7 is characterized in that: In step five, the top support (39) is composed of an arc-shaped top support (48) and a thickened straight piece angle code (49), four thickened straight piece angle codes (49) are welded to the arc-shaped top support (48), and then the bolt holes on the angle codes are aligned with the bolt holes on the middle plate, and then they are fastened by bolt connection; the top support (39) can change the inclination angle of the top support (39) by adjusting the angle between the U-shaped joint (63) and the thickened straight piece angle code (49) so as to fit the steel arch frame (51).

9. The construction method of a water-rich soft rock tunnel with a controlled blasting structure in close proximity under a flat tunnel according to any one of claims 1 to 8, characterized in that: In step six, the added temporary support (52) includes oblique supports (53) on both sides and a vertical support (54) in the middle, wherein a Y-shaped support member (55) and a T-shaped support member (56) are respectively connected to a support steel (58) by a flange (60) to form the oblique support (53) and the vertical support (54); The Y-shaped support member (55), the T-shaped support member (56) and the arc-shaped support steels (59) on both sides are connected by flanges (60) to form a temporary invert (57); The ends of the temporary support (52) and the temporary inverted arch (57) are respectively welded with arc-shaped connecting steel plates (61), and then the arc-shaped connecting steel plates (61) are installed on the steel arch frame (51) by means of third high-strength bolts.

10. A controlled blasting structure for a water-rich soft rock tunnel with close-range underpass, characterized by: The method is constructed by using the construction method of the controlled blasting structure of a water-rich soft rock tunnel passing through a flat hole at a close distance as described in any one of claims 1 to 9.

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