Comprehensive Treatment Structure and Construction Method for Invert Arch Defects in Water-Rich Soft Rock Operating Tunnels

Abstract

This invention discloses a comprehensive treatment structure and construction method for invert arch defects in water-rich soft rock operating tunnels, belonging to the field of tunnel maintenance technology. The structure includes a grouting reinforcement structure at the arch foot and a micro-steel pipe pile-steel cross brace reinforcement system for the foundation. The construction method employs an integrated drilling-pipe guide and fixing frame to assist in the precise installation of the steel pipe; using micro-steel pipe piles as a base to erect pluggable sliding guide rails, combined with a sliding steel hopper pouring frame and an intelligent control system, it achieves automated and symmetrical pouring of invert arch concrete within a confined space. This invention effectively solves the problems of invert arch settlement, bottom heave, and leakage in operating tunnels by constructing a rigid bearing system combining deep and shallow sections and using a dedicated set of sliding equipment, featuring high construction precision, high efficiency, and good overall structural stability.

Description

Technical Field

[0001] This invention belongs to the field of underground engineering and tunnel maintenance technology, specifically relating to a comprehensive treatment structure and construction method for repairing defects such as settlement, heave and leakage of the invert arch of an operating tunnel under special geological conditions of water-rich soft rock. Background Technology

[0002] With the rapid development of transportation infrastructure, numerous tunnel projects traverse water-rich soft rock strata. These strata are characterized by well-developed joints, softening upon contact with water, and strong rheological properties. During long-term operation, the tunnel invert structure is highly susceptible to deterioration due to the coupled effects of continuous groundwater seepage and erosion, repeated dynamic loads from trains, and the release of stress in the surrounding rock. Common forms of damage include cracking of the invert infill layer, floor bulging, uneven settlement, and severe water leakage. This not only weakens the overall load-bearing capacity of the tunnel but also directly threatens traffic safety.

[0003] Currently, the conventional treatment methods for defects in the invert arch of operating tunnels mainly include:

[0004] 1. Grouting reinforcement: Shallow grouting of the base layer is insufficient to form a continuous and effective water-blocking curtain under water-rich and dynamic conditions, and the grout is prone to loss and has poor durability.

[0005] 2. Partial replacement: Only partially excavating and replacing the severely damaged invert arch not only has a long construction period and causes great disruption to operation, but also results in a weak connection between the old and new structures, which cannot fundamentally improve the bearing capacity of the soft foundation.

[0006] 3. Simple drainage and pressure relief: Although it can alleviate water pressure, it cannot restore the strength of the surrounding rock, which is only a temporary solution.

[0007] Existing single treatment technologies often lack a systematic approach and struggle to address the challenge of synergistically addressing both "structural bearing capacity restoration" and "soil stability control." Furthermore, the extremely confined construction space within operating tunnels prevents the deployment of traditional large machinery, resulting in a lack of a complete set of technical equipment capable of achieving both deep reinforcement and rapid, precise, and low-disturbance construction. Summary of the Invention

[0008] Existing technologies mostly employ passive repair methods such as local grouting or shallow replacement, lacking a comprehensive rigid load-bearing system that combines deep and shallow layers. Furthermore, these methods suffer from low construction efficiency and poor precision within the confined space of operating tunnels, making it difficult to fundamentally solve the problems of insufficient bearing capacity and recurring defects in water-rich soft rock foundations. Therefore, the purpose of this invention is to provide a comprehensive treatment structure and construction method for defects in the invert arch of water-rich soft rock operating tunnels. The core of this invention lies in constructing a deep and shallow composite rigid reinforcement system consisting of "steel pipe grouting + micro steel pipe piles - steel cross bracing," and in conjunction with a complete set of equipment including an "integrated guide fixing frame" and an "insert-and-slide casting formwork," achieving precise reinforcement of the strata and automated, symmetrical construction of the structure within confined spaces.

[0009] The objective of this invention can be achieved through the following method: a comprehensive treatment structure for invert arch defects in water-rich soft rock operating tunnels, comprising:

[0010] The micro steel pipe pile-steel cross brace reinforcement structure is installed under the old invert arch of the tunnel, and the grouting reinforcement structure is installed at the arch foot of the tunnel.

[0011] The micro steel pipe pile-steel cross brace reinforcement structure includes multiple micro steel pipe piles driven into the foundation, a sleeve plate assembly fitted on top of the micro steel pipe piles, and steel cross braces connecting the sleeve plate assemblies.

[0012] The sleeve assembly is provided with a slot that matches the shape of the end of the steel cross brace. The steel cross brace is embedded in the slot and fixedly connected to the sleeve assembly by tie rods to form a connected tunnel floor load-bearing skeleton.

[0013] Furthermore, the sleeve assembly includes a side sleeve and a middle sleeve; the side sleeve is installed on the top of the micro steel pipe piles near both sides of the arch foot, and its inner side is provided with a slot; the middle sleeve is installed on the top of the micro steel pipe pile in the middle, and its two sides are symmetrically provided with slots; the side sleeve and the middle sleeve are provided with through tie rod holes, and the tie rods pass through the tie rod holes to lock the cross brace of the steel section.

[0014] Furthermore, the grouting reinforcement structure includes steel pipes installed at the arch foot and in the old invert arch; the treatment structure also includes a new invert arch and force-transmitting anchors. The new invert arch is cast on the micro steel pipe pile-steel cross brace reinforcement structure and connected to the tunnel arch foot through the force-transmitting anchors; the sidewalls of the steel pipes are provided with grouting holes.

[0015] A construction method for a comprehensive treatment structure for invert arch defects in water-rich soft rock operating tunnels, as described above, includes the following steps:

[0016] Step 1: Measurement and layout: Determine the location of each borehole;

[0017] Step 2: Install the integrated drilling-pipe installation guide and fixing frame: Install the guide and fixing frame at the tunnel arch foot, and use the guide and fixing frame to drill and install the steel pipe at the arch foot, and then perform grouting;

[0018] Step 3, Foundation reinforcement construction: Steel pipes are installed and grouting is performed at the location of the old invert arch; then the old invert arch is excavated, micro steel pipe piles are driven, and sleeve plate components and steel cross braces are installed to construct a micro steel pipe pile-steel cross brace reinforcement structure.

[0019] Step 4: Install sliding construction equipment: Install a pluggable sliding guide rail support frame on the top of the micro steel pipe pile, and install a sliding steel hopper casting frame on the support frame;

[0020] Step 5, Sliding Casting: Using a sliding steel hopper casting frame, the new invert arch and tunnel floor slab are symmetrically cast by sliding longitudinally along the plug-in sliding guide rail support frame; the sliding construction equipment is removed after the casting is completed.

[0021] Furthermore, the integrated drilling-pipe-laying guide and fixing frame used in step two includes an arc-shaped pressure plate; the arc-shaped pressure plate is attached to the top of the arch foot and anchored to the tunnel sidewall and the arch foot by inserts and bolts; the arc-shaped pressure plate has a pre-set steel pipe insertion hole with a guiding function, and the drill rod and steel pipe are operated through the steel pipe insertion hole.

[0022] Furthermore, the pluggable sliding guide support frame used in step four includes a support plate and a slide rail; the bottom of the support plate is provided with a reserved hole, through which it is fitted and fixed to the top of the micro steel pipe pile; the slide rail is set above the support plate for the sliding steel hopper casting frame to slide.

[0023] Furthermore, the sliding steel hopper casting frame used in step four includes a top plate, multiple columns, and a bottom slider; the slider is placed inside the slide rail; the bottom of the top plate and the columns are connected by inclined beams and cross beams to form a truss structure; the inner side of the columns is provided with connecting rods and ear plates.

[0024] Furthermore, the top plate of the sliding steel hopper casting frame is provided with a funnel inlet for installing the casting funnel; the casting funnel is fixed by a pair of clamping plates; the inner side of the pairing plates is provided with a semi-circular insertion hole, and the two pairing plates together form a fixing hole and are locked by a connecting rod.

[0025] Furthermore, the construction method also includes using an intelligent control system to control the pouring process; the intelligent control system is connected to the winch, which is connected to the ear plate via a wire rope; the intelligent control system is equipped with a winch position encoder and a tension sensor to control the winches on both sides to synchronously pull the sliding steel hopper pouring frame, and to perform tension compensation based on the tension feedback.

[0026] Furthermore, when installing the new invert arch or tunnel floor slab template in step five, the tie rod holes on the side of the side sleeve plate and the middle sleeve plate are used as positioning references; the template back rib is aligned with the tie rod holes, and temporary locking and positioning are performed by inserting rods. After the alignment is qualified, rigid fixation is performed.

[0027] Compared with traditional treatment techniques, this invention has the following significant advantages:

[0028] 1. A continuous rigid bearing system combining shallow and deep layers was constructed, significantly improving structural stability: Through a "micro-steel pipe pile-steel cross brace" structure, independent micro-piles are locked into an integral frame via steel cross braces and tie rods, forming a composite foundation due to the combined action of "piles-braces-rock." Combined with prior steel pipe grouting, comprehensive reinforcement from shallow water plugging and densification to deep rigid bearing was achieved, effectively resisting the rheology and heave of water-rich soft rock, and solving the problem of insufficient rigidity in traditional grouting reinforcement.

[0029] 2. Pioneering integrated drilling-pipe embedding guidance technology ensures construction accuracy under complex working conditions: The developed "integrated drilling-pipe embedding guide and fixing frame" utilizes an arc-shaped pressure plate and anchoring system to form a stable guiding platform. This avoids the problems of easy deviation during drilling and difficulty in controlling the embedding angle in fractured surrounding rock and narrow spaces, ensuring the precise implantation of the anchor pipe and grouting pipe, and guaranteeing the grouting reinforcement effect.

[0030] 3. Automated and symmetrical sliding pouring in confined spaces was achieved, significantly improving construction efficiency and quality: Using micropiles as a base, a "plug-in sliding guide rail support frame" was installed, in conjunction with a "sliding steel hopper pouring frame" and an intelligent control hoisting system, enabling automated sliding of the pouring equipment along the tunnel's longitudinal direction. This solution not only solved the problem of large equipment being unable to enter confined spaces but also achieved symmetrical and synchronous pouring of the invert arch concrete on both sides, effectively avoiding formwork deformation caused by eccentric loading and significantly shortening construction time.

[0031] 4. Modular quick-release connection design to meet the construction needs of operational tunnels during "maintenance windows": The device adopts a modular design with interlocking clamping plates, semi-circular insertion holes, and pluggable connectors, making installation and disassembly convenient and highly reusable. It is particularly suitable for the characteristics of operational tunnels that can only utilize short "maintenance windows" for operation, greatly reducing the difficulty and cost of construction organization.

[0032] 5. Enhanced the reliability of force transmission between the old and new structures: By setting force transmission anchors at the arch foot and firmly connecting the new invert arch with the existing arch foot, and in conjunction with the micropile reinforcement system at the bottom, it is ensured that the reinforced invert arch can form an integral load-bearing structure with the original tunnel lining, avoiding the separation of the old and new interfaces and extending the service life of the tunnel. Attached Figure Description

[0033] Figure 1 This is a three-dimensional schematic diagram of the construction structure for the comprehensive treatment of arch defects in water-rich soft rock operating tunnels;

[0034] Figure 2 This is a three-dimensional schematic diagram of the drilling construction of micro steel pipe piles and steel perforated pipes;

[0035] Figure 3 This is a three-dimensional schematic diagram of the construction of miniature steel pipe piles and steel perforated pipes;

[0036] Figure 4 This is a three-dimensional schematic diagram of the construction of tunnel floor slab reinforcement treatment using micro steel pipe piles and steel cross braces;

[0037] Figure 5 This is a three-dimensional schematic diagram of the grouting reinforcement construction of the arch foot and the base steel pipe;

[0038] Figure 6 This is a 3D schematic diagram of an integrated drilling-pipe-laying guide and fixing frame;

[0039] Figure 7 This is a three-dimensional schematic diagram of the synchronous traction and sliding construction of the hopper pouring frame;

[0040] Figure 8 This is a three-dimensional schematic diagram of the bottom structure of the sliding steel hopper casting frame;

[0041] Figure 9 This is a three-dimensional schematic diagram of the assembly of a sliding steel hopper casting frame;

[0042] Figure 10 This is a three-dimensional schematic diagram of the top structure of the sliding steel hopper casting frame;

[0043] Figure 11 This is a three-dimensional schematic diagram of a plug-in sliding guide rail support frame;

[0044] Figure 12 This is a three-dimensional schematic diagram of the bottom structure of the plug-in sliding guide rail support frame;

[0045] Figure 13 This is a three-dimensional schematic diagram of the splicing clamping plate;

[0046] Figure 14 This is a schematic diagram of the cross-section of the sliding guide rail;

[0047] Figure 15 This is a cross-sectional schematic diagram of the connection between the hopper casting frame and the sliding guide rail;

[0048] Figure 16 This is a three-dimensional schematic diagram of the connection between the micro steel pipe pile sleeve and the steel cross brace;

[0049] Figure 17 This is a three-dimensional schematic diagram of the detailed structure of the micro steel pipe pile sleeve plate;

[0050] Figure 18 This is a cross-sectional view after the completion of the comprehensive treatment of the arch defects in the water-rich soft rock operating tunnel.

[0051] In the diagram: 1. Tunnel main body; 2. Steel pipe hole; 3. Steel pipe pile hole; 4. Anchor bolt hole; 5. Old invert arch; 6. Inserted nail hole; 7. Arch foot; 8. Grouting hole; 9. Steel pipe; 10. Semi-circular insertion hole; 11. Screw rod; 12. Bolt; 13. Micro steel pipe pile; 14. Slot; 15. Steel cross brace; 16. Inserted nail; 17. Arc-shaped pressure plate; 18. Side sleeve plate; 19. Tie rod; 20. Middle sleeve plate; 21. Nut; 22. Slide rail groove; 23. Top plate of hopper casting frame; 24. Casting funnel; 25. Tie rod hole; 26. Slide rail; 27. Winch; 28. 29. Support plate; 30. Intelligent control system; 31. Screw; 32. Splicing clamping plate; 33. Steel pipe pile insertion hole; 34. Steel flower pipe insertion hole; 35. Screw hole; 36. Ear plate; 37. Column; 38. Sliding block; 39. Connecting rod; 40. Pouring hole; 41. Wire; 42. Fixing nut; 43. Insert rod; 44. Diagonal brace; 45. Horizontal brace; 46. Crossbeam; 47. Inclined beam; 48. Funnel insertion port; 49. Screw insertion port; 50. Insertion hole; 51. Steel wire rope; 52. Reserved hole; 53. Tunnel floor slab; 54. New invert arch; 55. Force transmission anchor rod. Detailed Implementation

[0052] The construction technical requirements for steel pipe welding and cutting, rebar cage binding, and concrete pouring in the embodiments of the present invention will not be repeated. The focus is on explaining the implementation of the present invention. The present invention will be further described in detail below with reference to the accompanying drawings and through embodiments. This description is not limited to the following embodiments.

[0053] Example 1

[0054] This embodiment provides a comprehensive treatment structure for invert arch defects in water-rich soft rock operating tunnels, such as... Figures 1 to 18 As shown, the structure mainly consists of two parts: a permanent reinforcement and load-bearing system and temporary auxiliary construction equipment used during construction.

[0055] A permanent reinforcement and load-bearing system is installed at the bottom of the tunnel body 1. Specifically, it includes a grouting reinforcement structure installed at the arch foot 7 and a micro steel pipe pile-steel cross brace reinforcement structure installed below the old invert arch 5.

[0056] The grouting reinforcement structure includes steel pipes 9 embedded inside the arch foot 7 and the old invert arch 5. The steel pipes 9 are installed in pre-drilled steel pipe holes 2. Multiple grouting holes 8 are opened on the side wall of the steel pipes 9 for injecting grout into the surrounding rock to achieve water blocking and formation densification.

[0057] The micro-steel pipe pile-steel cross brace reinforcement structure forms the rigid skeleton of the tunnel bottom. It includes multiple vertically driven micro-steel pipe piles 13, which are installed in steel pipe pile holes 3. In order to connect the independent individual piles into a whole, a sleeve assembly is fitted on the top of the micro-steel pipe pile 13, and steel cross braces 15 are connected between the sleeve assemblies.

[0058] The sleeve assembly specifically includes side sleeve plates 18 located on both sides and a middle sleeve plate 20 located in the middle. Both the side sleeve plates 18 and the middle sleeve plate 20 have steel pipe pile insertion holes 32 at their tops. The pile heads of the micro steel pipe piles 13 pass through these insertion holes 32 and are welded and fixed to the sleeve plates. The inner surface of the side sleeve plates 18 has multiple rows of I-shaped slots 14, and the two sides of the middle sleeve plate 20 have symmetrically arranged multiple rows of I-shaped slots 14. The two ends of the steel cross brace 15 are respectively embedded in the slots 14 of the side sleeve plates 18 and the middle sleeve plate 20. To lock this connection, the sides of the side sleeve plates 18 and the middle sleeve plate 20 have through tie rod holes 25. The tie rods 19 pass sequentially through the tie rod holes 25 and the web of the steel cross brace 15 (the web holes are not shown in the figure, but this is a conventional mechanical connection), and are tightened and fixed by nuts 21, thus forming a connected force-bearing system of "pile-sleeve plate-cross brace".

[0059] On top of the aforementioned reinforced structure, a new inverted arch 54 and a tunnel floor slab 53 were cast. To strengthen the connection between the new and old structures, a force-transmitting anchor 55 was installed between the new inverted arch 54 and the original arch foot 7. One end of the force-transmitting anchor 55 was inserted into the side of the arch foot 7, and the other end was cast into the new inverted arch 54.

[0060] This embodiment also relates to a set of dedicated auxiliary construction equipment, including an integrated drilling-pipe laying guide and fixing frame for assisting in the construction of steel pipe, and a sliding construction component for concrete pouring.

[0061] The integrated drilling-pipe-laying guide and fixing frame includes an arc-shaped pressure plate 17 that fits above the arch foot 7. Multiple rows of pins 16 are symmetrically arranged on the sides of the arc-shaped pressure plate 17, and these pins 16 are inserted into the pin holes 6 on the sidewalls of the tunnel body 1 and the arch foot 7. Screw holes 34 are provided at both ends of the arc-shaped pressure plate 17, through which screws 11 are inserted into the anchor holes 4 on the arch foot 7, and secured with bolts 12. The arc-shaped pressure plate 17 has pre-set steel pipe insertion holes 33 with a guiding angle. The drill rod and steel pipe 9 operate through these steel pipe insertion holes 33, thereby ensuring the angular accuracy of drilling and pipe laying.

[0062] The sliding construction assembly includes a pluggable sliding guide support frame mounted on top of the micro steel pipe pile 13, and a sliding steel hopper casting frame running thereon.

[0063] The pluggable sliding guide support frame includes a support plate 28, with a pre-drilled hole 52 at its bottom. The pre-drilled hole 52 engages with the top of the central micro steel pipe pile 13, allowing the support plate 28 to be securely fitted onto the pile head. Parallel slide rails 26 are arranged on both sides of the top of the support plate 28, with recessed slide rail grooves 22 on their upper surfaces. A pouring hole 39 is located in the center of the support plate 28 to facilitate the downward conveying of concrete.

[0064] The sliding steel hopper casting frame includes a top plate 23, with six columns 36 positioned below it. A slider 37 is installed at the bottom of each column 36, slidingly engaging within a slide rail groove 22. To ensure the frame's rigidity, adjacent columns 36 are connected by diagonal braces 43 and horizontal braces 44. An inclined beam 46 connects the top plate 23 to the outer columns 36, and a horizontal beam 45 connects adjacent inclined beams 46. A connecting rod 38 is located at the bottom inner side of each column 36, with an ear plate 35 at its end. This ear plate 35 serves both to connect the traction rope and as a positioning reference for template installation.

[0065] The top plate 23 of the hopper casting frame is equipped with a quick-fixing mechanism for installing the casting funnel 24. Specifically, the top plate has multiple rows of funnel inlets 47 in the center and screw inlets 48 on both sides. The casting funnel 24 is fixed by the splicing clamping plates 31. The inner side of the splicing clamping plates 31 has a semi-circular insertion hole 10. After two splicing clamping plates 31 are spliced, the semi-circular insertion holes 10 form a circular hole that holds the neck of the casting funnel 24 and aligns it with the funnel inlets 47 below. The splicing clamping plates 31 are connected by inserting rods 42 through through holes 50 and tightening fixing nuts 41; the entire splicing clamping plate 31 is secured to the top plate 23 of the hopper casting frame by screws 30 passing through the inlets 49 on it and the screw inlets 48 on the top plate, and locking it with fixing nuts 41.

[0066] To achieve automated movement, a winch 27 is installed on the support plate 28 at the front end of the slide rail 26. The winch 27 is connected to the ear plate 35 at the bottom of the sliding steel hopper casting frame via a wire rope 51. The winch 27 is connected to an intelligent control system 29 via a wire 40. This system is located in front of the support plate 28 and can control the winches on both sides to synchronously wind up and unwind the wire rope.

[0067] Preferably, the intelligent control system 29 includes: a winch position / speed encoder, a winch tension sensor, a slide rail linear displacement sensor, limit switches, and a human-machine interface; the intelligent control system 29 is connected to three winches 27 via wires 40 and implements synchronous control of their displacements and tension compensation based on tension feedback; when the position error or tension difference between the two sides exceeds a preset threshold, the control system issues an alarm and triggers a hardware emergency stop. Preferably, the control system is equipped with dual sensor redundancy, a data recording module, and a self-testing module to ensure safe and stable construction under water-rich soft rock conditions.

[0068] Example 2

[0069] This embodiment provides a construction method for a comprehensive treatment structure for invert arch defects in water-rich soft rock operating tunnels using the above-described structure. The specific steps are as follows:

[0070] Step 1) Measure and lay out the lines

[0071] The designed locations of steel pipe hole 2, steel pipe pile hole 3, anchor bolt hole 4, and nail hole 6 were measured and marked inside the tunnel.

[0072] Step 2) Construction of the integrated drilling-pipe laying guide and fixing frame

[0073] The integrated drilling-pipe guide and fixing frame is transported to the work site and installed at the intersection of the sidewall of the tunnel body 1 and the arch foot 7. The specific operation is as follows: the pins 16 on the arc-shaped pressure plate 17 are inserted into the pre-marked pin holes 6, and the screw 11 is inserted through the screw hole 34 into the anchor hole 4. The bolts 12 are then tightened to make the arc-shaped pressure plate 17 tightly pressed against the surrounding rock surface, forming a stable drilling platform.

[0074] Step 3) Tunnel main body sidewall reinforcement construction

[0075] The steel pipe insertion hole 33 at a preset angle on the top of the arc-shaped pressure plate 17 serves as a guide. First, the drill rod of the drilling rig is passed through the steel pipe insertion hole 33, and a steel pipe hole 2 is precisely drilled on the arch foot 7. After drilling, the steel pipe 9 is inserted into the hole through the steel pipe insertion hole 33, and a reinforcing cage (if any) is placed in. Grouting is performed through the grouting holes 8 on the side wall of the steel pipe 9 for reinforcement. Finally, the end of the steel pipe 9 is sealed with mortar. This step, through integrated guidance, avoids the problem of drilling deviation on broken soft rock.

[0076] Step 4) Construction of steel pipe for base grouting

[0077] The drilling rig was moved above the old invert arch 5, and a hole was drilled at the measured position of the steel pipe hole 2. The steel pipe 9 was inserted, the steel cage was placed in, and grouting was performed to reinforce it. The grout was used to initially plug the water and improve the soft rock of the base.

[0078] Step 5) Grouting reinforcement and excavation of the old invert arch

[0079] Temporary support steel frames (not shown in the figure) were installed between the arch feet 7 to maintain structural stability. Then, the old invert arch 5 was excavated to expose the soft rock working face at the bottom of the tunnel.

[0080] Step 6) Construction of the micro-steel pipe pile-steel cross brace reinforcement structure

[0081] On the excavated foundation, holes were drilled at the measured locations of the steel pipe pile holes 3 using a drilling rig, and micro steel pipe piles 13 were installed. Connecting components were installed between the rows of micro steel pipe piles 13: side sleeve plates 18 were fitted onto the top of the micro steel pipe piles 13 near the arch foot, and middle sleeve plates 20 were fitted onto the top of the middle micro steel pipe piles 13, and then welded and fixed. Subsequently, steel cross braces 15 were placed into the slots 14 between the side sleeve plates 18 and the middle sleeve plates 20, and between adjacent middle sleeve plates 20. Finally, tie rods 19 were passed through tie rod holes 25 and steel cross braces 15, and nuts 21 were tightened to apply preload to the entire base plate frame, forming a rigid reinforcement system.

[0082] Step 7) Install the plug-in sliding guide rail support frame

[0083] A pluggable sliding guide support frame is installed on top of the micro steel pipe pile 13 in the middle using a crane. Specifically, the pre-drilled hole 52 at the bottom of the support plate 28 is aligned with the micro steel pipe pile 13 and inserted, achieving rapid positioning without welding. Subsequently, a winch 27 and an intelligent control system 29 are installed at the end of the support plate 28 and connected with wires 40.

[0084] Step 8) Install the sliding steel hopper casting frame

[0085] Assemble the sliding steel hopper casting frame onto the track. Place the slider 37 at the bottom of the column 36 into the slide rail groove 22 at the top of the slide rail 26. Install the splicing clamping plate 31 on the top plate 23 of the hopper casting frame: place the casting funnel 24 into the semi-circular insertion hole 10 and the funnel insertion opening 47, and lock the funnel and clamping plate together using the insertion rod 42, screw 30 and fixing nut 41. At the same time, pull out the wire rope 51 of the winch 27 and hook it onto the ear plate 35 at the bottom of the column 36.

[0086] Step 9) Construction of the new invert arch and tunnel floor slab

[0087] The concrete pouring stage begins. First, the formwork for the new invert arch 54 is installed. At this stage, the tie rod holes 25 on the sides of the side sleeve plate 18 and the middle sleeve plate 20 are used as positioning references. The back rib of the formwork is aligned with the tie rod holes 25, and temporary locking is completed using the insertion rod 42 to ensure accurate formwork positioning. After the reinforcing cage is placed, the operator starts the winch 27 via the intelligent control system 29. Based on feedback from built-in sensors, the intelligent control system 29 controls the winches 27 on both sides to synchronously pull the sliding steel hopper pouring frame along the slide rail 26, achieving symmetrical synchronous pouring of the new invert arch 54 on both sides through the pouring funnel 24 and the pouring holes 39 on the support plate 28. Simultaneously, force-transmitting anchor rods 55 are drilled and inserted into the side of the arch foot 7, connecting them to the reinforcing steel of the new invert arch 54. After the new invert arch 54 reaches its design strength, the above sliding pouring steps are repeated to pour the tunnel floor slab 53. After the tunnel floor slab 53 reaches the required strength, the plug-in sliding guide rail support frame and the sliding steel hopper casting frame are removed to complete the construction.

[0088] Template installation and alignment: First, arrange template back ribs on the steel cross braces 15 at the top of the micro steel pipe piles 13 on both sides, and align the ear plates at the ends of the back ribs with the reserved holes 52 of the side / middle sleeve plates 18 and 20. Temporarily lock them with the insert rods 42 and fixing nuts 41 to complete the initial positioning.

[0089] Preferably, after the alignment is deemed satisfactory, the back brace and the cross brace of the steel section are rigidly locked together using the insert rod 42 and the fixing nut 41, confirming that the connecting parts such as the tie rod 19 have been pre-tightened to the design force value. At this time, the main vertical and horizontal load transfer paths of the formwork are: formwork → back brace → cross brace of steel section → micro steel pipe pile → foundation.

[0090] Preferably, the pouring and sliding operation is performed as follows: the installed and calibrated sliding hopper pouring frame is placed and the funnel 24 is aligned with the semi-circular insertion hole 10. The two hoppers are synchronously slid and poured through the winch 27 and the control system 29. During pouring, it is strictly forbidden to transfer the vertical load of the template to the slide rail 26.

[0091] The embodiments of the present invention are not limited to the specific embodiments described above. Any modifications and improvements made by those skilled in the art without departing from the concept of the present invention shall fall within the protection scope of the present invention.

Claims

1. A construction method of a comprehensive treatment structure for water-rich soft rock tunnel invert disease, characterized in that, The method comprises the following steps: Step 1: measuring the wire: determining the position of each drill hole; Step 2: installing a drill-pipe integrated guide fixing frame: Install the guide fixing frame at the position of the tunnel arch foot (7), use the guide fixing frame to drill and install the steel pipe (9) at the arch foot (7), and form a grouting reinforcement structure by grouting; wherein the grouting reinforcement structure comprises a steel pipe (9) arranged in the arch foot (7) and the old inverted arch (5), and the steel pipe (9) is provided with a grouting hole (8) on the side wall; Step 3: base reinforcement construction: Construct the steel pipe (9) at the position of the old inverted arch (5) and grout; Then excavate the old inverted arch (5), set the micro steel pipe pile (13), install the sleeve plate assembly and the steel cross brace (15), and build a micro steel pipe pile-steel cross brace reinforcement structure; wherein the micro steel pipe pile-steel cross brace reinforcement structure is arranged below the old inverted arch (5), the micro steel pipe pile-steel cross brace reinforcement structure comprises a plurality of micro steel pipe piles (13) punched into the base, a sleeve plate assembly arranged on the top of the micro steel pipe pile (13), and a steel cross brace (15) connected between the sleeve plate assemblies, the sleeve plate assembly is provided with a clamping groove (14) matched with the shape of the end of the steel cross brace (15), the steel cross brace (15) is embedded in the clamping groove (14) and fixedly connected with the sleeve plate assembly through the tensioning screw rod (19), and a connected tunnel bottom plate bearing framework is formed; the sleeve plate assembly comprises a side sleeve plate (18) and a middle sleeve plate (20); the side sleeve plate (18) is installed on the top of the micro steel pipe pile (13) near the two sides of the arch foot, and the inner side surface is provided with a clamping groove (14); the middle sleeve plate (20) is installed on the top of the micro steel pipe pile (13) in the middle, and the two sides are symmetrically provided with clamping grooves (14); the side surfaces of the side sleeve plate (18) and the middle sleeve plate (20) are provided with through tensioning screw rod holes (25), and the tensioning screw rod (19) passes through the tensioning screw rod holes (25) to lock the steel cross brace (15); Step 4: installing a sliding construction device: installing a plug-in sliding guide rail support frame on the top of the micro steel pipe pile (13), and installing a sliding steel hopper pouring frame on the support frame; Step 5: sliding pouring: using the sliding steel hopper pouring frame to slide along the plug-in sliding guide rail support frame, symmetrically pouring the new inverted arch (54) and the tunnel bottom plate (53); after pouring, the sliding construction device is removed; the new inverted arch (54) is poured on the micro steel pipe pile-steel cross brace reinforcement structure, and is connected with the tunnel arch foot (7) through the force transmission anchor rod (55).

2. The construction method according to claim 1, characterized in that, The drill-pipe integrated guide fixing frame used in step 2 comprises an arc-shaped pressing plate (17); the arc-shaped pressing plate (17) is attached to the top of the arch foot (7) and is anchored to the tunnel side wall and the arch foot through the insertion nail (16) and the screw rod (11); the arc-shaped pressing plate (17) is provided with a steel pipe insertion hole (33) with a guide function, and the drill rod and the steel pipe (9) are operated through the steel pipe insertion hole (33).

3. The construction method according to claim 1, characterized in that, The plug-in sliding guide rail support frame used in step four comprises a support plate (28) and a sliding rail (26); the bottom of the support plate (28) is provided with a reserved hole (52) through which a micro steel pipe pile (13) is fixed on the top of the micro steel pipe pile (13); the sliding rail (26) is arranged above the support plate (28) and is used for sliding of the sliding steel hopper pouring frame.

4. The construction method according to claim 3, characterized in that, The sliding steel hopper pouring frame used in step four comprises a top plate (23), a plurality of columns (36) and a bottom sliding block (37); the sliding block (37) is arranged in the sliding rail (26); the top plate (23) and the columns (36) are connected through inclined beams (46) and cross beams (45) at the bottom to form a truss structure; the inside of the column (36) is provided with a connecting rod (38) and an ear plate (35).

5. The construction method according to claim 4, characterized in that, The top plate (23) of the sliding steel hopper pouring frame is provided with a funnel socket (47) for mounting a pouring funnel (24); the pouring funnel (24) is fixed through a split clamping plate (31); the split clamping plate (31) is provided with a semicircular insertion hole (10) on the inside, and two split clamping plates (31) are combined to form a fixing hole and are connected and locked through an insertion rod (42).

6. The construction method according to claim 4, characterized in that, The construction method further comprises using an intelligent control system (29) to control the pouring process; the intelligent control system (29) is connected with a winch (27), the winch (27) is connected to the ear plate (35) through a steel wire rope (51); the intelligent control system (29) is provided with a winch position encoder and a tension sensor, which are used for controlling the synchronous traction of the sliding steel hopper pouring frame by the winches (27) on both sides and tension compensation according to the tension feedback.

7. The construction method according to claim 5, characterized in that, In step five, when the new inverted arch (54) or tunnel bottom plate (53) template is installed, the side pull screw hole (25) arranged on the side of the side sleeve plate (18) and the middle sleeve plate (20) is used as a positioning reference; the template back rib is aligned with the side pull screw hole (25), and is temporarily locked and positioned through the insertion rod (42); after correction, rigid fixation is performed.

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