Treatment System and Construction Method for Arching Defects in Operating Tunnels in Underlying Karst Formations

Abstract

This invention provides a system and construction method for treating arching defects in the pavement of operating tunnels located in underlying karst strata. The tunnel lining is pre-reinforced by installing an arc-shaped I-beam internal support frame. The height and tension of the I-beam internal support frame are adjusted using longitudinal steel beams. After pre-reinforcement, the concrete pavement layer and the underlying broken rock layer are excavated, and the middle section of the tunnel invert is poured. The surrounding rock pressure is transferred to the middle invert via the supporting steel frame. The surrounding rock at the arch foot is then excavated, and concrete is poured to form a closed structure, transferring the tunnel's surrounding rock pressure to the invert. After the closed invert is constructed, the concrete lining is reinforced using a combination of "W-shaped steel strip + anchor grouting + sprayed steel fiber concrete" to solve problems such as cracking, heave, deformation, and voiding in the operating tunnel. Grooves are cut at the transverse expansion joints where water seepage occurs, and channel steel is pre-embedded in the grooves as a water guiding channel to promptly drain seepage water from the pavement into the drainage ditches on both sides.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of operating tunnel comprehensive treatment construction, in particular to a subsurface karst stratum operating tunnel pavement arching disease treatment system and construction method. BACKGROUND

[0002] With the rapid development of highway construction in China, the mileage of highway tunnels is increasing. Highway tunnels often pass through complex geological strata, such as subsurface karst strata, water-rich geology, and soft rock strata, which brings great challenges to the design, construction, and later maintenance of tunnels, especially for some tunnels in earlier years that did not fully explore the underground geological conditions, in order to save costs for economic benefits, inverted arches were not set, resulting in the following problems in tunnel operation after many years:

[0003] (1) There are broken carbonaceous limestones in the lower part of the tunnel, and there are local caves or cavities, causing the tunnel pavement to sink to varying degrees.

[0004] (2) The lower part of the tunnel has a water seepage channel, which causes the pavement to rise under the action of water pressure in the rainy season. The pavement uplift causes extrusion of the arch foot to the outside, and the lining deforms and cracks to the surrounding rock under the extrusion.

[0005] (3) The surrounding rock around the tunnel is relatively broken, and effective reinforcement measures were not taken during construction. After many years of operation, the arch top and side wall have multiple cracking, voiding, and under-reinforcement diseases under the action of natural settlement.

[0006] (4) Underground water connects longitudinal and transverse expansion joints through seepage joints in some sections, and underground water flows out of the pavement, posing a hidden danger to tunnel driving safety. SUMMARY

[0007] The purpose of the present application is to provide a subsurface karst stratum operating tunnel pavement arching disease treatment system and construction method to solve the above technical problems.

[0008] To solve the above technical problems, the present application provides a construction method for a subsurface karst stratum operating tunnel pavement arching disease treatment system, comprising the following steps:

[0009] Step 1, construction preparation: use geological radar detection equipment, seismic surface wave exploration equipment, and crack depth and width detection equipment to detect and mark the number and location of caves and through cracks in broken carbonaceous limestones, the location and number of concrete pavement cracking and uplift, the number and water seepage amount of seepage joints, the crack depth and number of concrete lining, and the number of hollowing, under-reinforcement, and voiding diseases between concrete lining and reserved deformation.

[0010] Step 2, Lining Pre-reinforcement: Remove the cable trench, chisel away the locally broken carbonaceous limestone at the arch foot, clean up the stone debris and level it, then assemble the arc-shaped I-beam inner support into a ring in sections. The inner support of the I-beam is tightly attached to the concrete lining. After adjusting the position and tightness of the inner support of the I-beam, install locking anchor rods to lock the feet of the inner support of the I-beam.

[0011] Step 3: Grouting reinforcement of fractured carbonaceous limestone: In areas where there are karst caves, through cracks, and arching of concrete pavement beneath the fractured carbonaceous limestone, boreholes are drilled through the concrete pavement to a certain depth beneath the fractured carbonaceous limestone. Several grouting pipes are inserted into the boreholes in an array. Cement grout is first injected into the boreholes through the grouting pipes, followed by a cement grout + water glass grout. The grouting process fills the karst caves and through cracks, thereby strengthening the fractured carbonaceous limestone.

[0012] Step 4: Remove cracked and bulging concrete pavement: If the grouting reinforcement effect is poor, excavate and remove the cracked and bulging concrete pavement, and excavate and remove the broken carbonaceous limestone under the concrete pavement to a certain depth. Leave the surrounding rock at the arch foot without excavating or removing it.

[0013] Step 5: Construction of the invert arch in the center of the road surface: The invert arch is poured in layers. After the invert arch reaches a certain strength, an arc-shaped steel plate with a matching curvature is placed on the invert arch.

[0014] Step 6: Construction of the invert arch at the arch foot: After the pressure of the surrounding rock around the tunnel is transferred to the invert arch, the surrounding rock at the arch foot is removed, and the invert arch concrete at the arch foot is poured to connect the invert arch with the initial support and concrete lining to form a closed structure. After the invert arch concrete reaches the designed strength, the supporting steel frame, arc steel plate, anchor bolt, and I-beam internal support are removed in sequence, the invert arch filling layer is backfilled, and the cable trench and drainage ditch are restored.

[0015] Step 7, W-steel strip installation: After the invert arch and invert arch filling layer are completed, the W-steel strip with pre-drilled holes for anchor bolts is tightly attached to the cracked concrete lining and the W-steel strip is fixed to the surface of the concrete lining.

[0016] Step 8: Grouting Anchor Installation: Drill grouting holes into the fractured surrounding rock along the anchor holes reserved in the W steel strip. The grouting holes are arranged in a quincunx pattern. Insert the grouting anchor into the grouting hole and fix the end of the grouting anchor to the W steel strip. First inject single-component cement grout into the grouting anchor, and then inject double-component grout of "cement grout + water glass".

[0017] Step 9, Steel Fiber Concrete Shotcrete: Lay a steel mesh on the surface of the W-steel strip, spray steel fiber concrete onto the W-steel strip to seal the W-steel strip and the grouting anchor rods, and then apply polymer mortar to the surface after spraying the steel fiber concrete.

[0018] Step 10, Grooving the transverse expansion joint for seepage: For road sections where seepage joints in the fractured carbonaceous limestone are connected to transverse expansion joints in the concrete pavement, resulting in a large amount of water seepage in the concrete pavement, grooves are chiseled at the transverse expansion joints.

[0019] Step 11: Install the channel steel: Pre-embed the channel steel in the groove, ensuring that the channel steel presses down on the seepage joint;

[0020] Step 12: Filling and leveling the grooves: Use waterproof geotextile to fill the gaps on both sides of the channel steel, cover the waterproof geotextile with polymer mortar, and after the surface of the polymer mortar sealant has dried, fill and compact the grooves with early-strength cement-based grout to restore the original state of the road surface.

[0021] The beneficial effects of this invention are as follows:

[0022] 1. This invention first sets up an arc-shaped I-beam internal support steel frame for lining pre-reinforcement. After lining pre-reinforcement, the concrete pavement layer and the broken rock layer under the pavement are excavated, and the middle part of the tunnel invert arch is poured. The surrounding rock pressure is transferred to the middle part of the invert arch through the supporting steel frame. Then, the surrounding rock at the arch foot is excavated and concrete is poured to form a closed structure. The lining pre-reinforcement ensures the normal construction of the invert arch. By setting the invert arch, the closure of the tunnel lining is achieved, which improves the structural strength of the tunnel.

[0023] 2. The internal support steel frame of the I-beam of this invention is adjusted in height and tightness by longitudinal steel lifting beams. By setting up the supporting steel frame, the pressure of the surrounding rock of the tunnel is transferred to the middle part of the invert. After the invert is closed, the supporting steel frame, the internal support of the I-beam and other pre-reinforcement structures are removed, and the pressure of the surrounding rock of the tunnel is transferred to the closed invert, which solves the risk of the tunnel collapsing due to lack of support structure during the construction of the invert.

[0024] 3. After the invert arch is installed, the cracked concrete lining is reinforced by a combination of "W steel strip + anchor grouting + sprayed steel fiber concrete" to solve problems such as cracking, heave, deformation and voiding in the operating tunnel.

[0025] 4. This invention adopts a construction process of pre-reinforcement of the inner support steel frame of the lining → grouting reinforcement of the broken rock layer under the road surface → excavation and pouring of the middle part of the inverted arch → transfer of surrounding rock pressure to the middle inverted arch → excavation and pouring of the arch foot inverted arch → removal of the lining pre-reinforcement structure → transfer of surrounding rock pressure to the closed inverted arch → "W steel strip + anchor grouting + sprayed steel fiber concrete" combined reinforcement, which effectively solves the problem of tunnel defects in the underlying karst strata without an inverted arch.

[0026] 5. This invention solves the problem of road surface cracking and water seepage in tunnels without an inverted arch by cutting grooves at the transverse expansion joints where water seepage occurs, pre-embedding channel steel in the grooves as a water guiding channel, connecting both ends of the channel steel to the drainage ditch, and filling the gaps on both sides of the channel steel with waterproof geotextile and polymer mortar to seal and waterproof, so that the seepage water in the seepage joints under the road surface can be discharged to the drainage ditches on both sides in a timely manner. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the structural principle of arching defects in the road surface of an operating tunnel in an underlying karst stratum, as per the present invention.

[0028] Figure 2 This is a diagram illustrating the grouting reinforcement of fractured rock layers beneath the road surface of the tunnel in the underlying karst strata of this invention.

[0029] Figure 3 This is an enlarged view of the bottom mounting and fixing structure of the arc-shaped I-beam inner support steel frame of the present invention;

[0030] Figure 4 This is a diagram of the intermediate invert arch structure for the pre-reinforcement excavation and casting of the underground karst strata operating tunnel according to the present invention;

[0031] Figure 5 This is a diagram showing the force transmission from the pre-reinforced structure of the underground karst stratum tunnel to the intermediate invert arch structure.

[0032] Figure 6 This is a diagram showing the completed casting of the pre-reinforced invert arch closed loop for the operating tunnel in the underlying karst strata of this invention;

[0033] Figure 7 This is a diagram of the combined reinforcement structure of "W steel strip + anchor bolt grouting + shotcrete steel fiber concrete" for the underground karst strata tunnel of this invention;

[0034] Figure 8 This is a detailed drawing of the W-steel strip structure of the present invention;

[0035] Figure 9 This is a plan view of the transverse expansion joint groove embedded in the channel steel of the tunnel seepage pavement according to the present invention;

[0036] Figure 10 This is a cross-sectional view of the transverse expansion joint groove embedded in the channel steel of the tunnel seepage pavement of the present invention. Figure 9 (Cross-section view of AA)

[0037] Figure 11 This is a detailed drawing of the installation of channel steel and waterproof structure in the groove at the transverse expansion joint of the road surface according to the present invention. Figure 10 (Cross-section view of BB)

[0038] Figure 12 This is a detailed drawing showing the connection between the end of the channel steel and the drainage ditch in this invention.

[0039] Among them: 1-Initial support; 2-Reserved deformation amount; 3-Concrete lining; 4-Fractured carbonaceous limestone; 5-Keloid cave; 6-Water pressure; 7-Concrete pavement; 8-Through crack; 9-External thrust; 10-Cable trough; 11-Drainage ditch; 12-I-beam internal support; 13-Steel bracing frame; 14-Anchor bolt; 15-Grouting pipe; 16-Longitudinal steel lifting beam; 17-Adjustable support; 18-Supporting steel plate; 19-Arch foot. Surrounding rock; 20-Inverted arch; 21-Arc-shaped steel plate; 22-Inverted arch filling layer; 23-Fractured surrounding rock; 24-W-steel strip; 25-Steel fiber reinforced concrete; 26-Grouting anchor; 27-Anchor hole; 28-Transverse expansion joint; 29-Channel steel; 30-Groove; 31-Early-strength cement-based grouting material; 32-Seepage joint; 33-Water barrier; 34-Waterproof geotextile; 35-Polymer mortar; 36-Water diversion channel; 37-Tongue and groove joint. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0041] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0042] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0043] like Figures 1-12 The present invention provides a construction method for a system to treat arching defects in the pavement of operating tunnels in underlying karst strata, comprising the following steps:

[0044] Step 1, Construction Preparation: Using ground-penetrating radar detection equipment, seismic surface wave exploration equipment, and crack depth and width detection equipment, the quantity and location of karst caves 5 and through cracks 8 in the fractured carbonaceous limestone 4, the location and number of cracks and uplifts in the concrete pavement 7, the number and amount of water seepage cracks 32, the depth and number of cracks in the concrete lining 3, and the number of hollow, undercompacted, and detached defects between the concrete lining 3 and the reserved deformation amount 2 are detected and marked, and a special treatment plan is formulated.

[0045] Step 2, Lining Pre-Reinforcement: Remove the cable trough 10, chisel away the locally broken carbonaceous limestone 4 at the arch foot, clean up the stone debris and level it, then set up adjustable supports 17, place support steel plates 18 on the adjustable supports 17, place longitudinal steel lifting beams 16 on the support steel plates 18, assemble the arc-shaped I-beam inner support 12 into a ring in sections, with the I-beam inner support 12 tightly attached to the concrete lining 3, and the feet of the I-beam inner support 12 supported on the longitudinal steel lifting beams 16. After adjusting the position and tension of the I-beam inner support 12, install locking anchor rods 14 to lock the feet of the I-beam inner support 12. Set up supporting steel frames 13 inside the ring of the I-beam inner support 12 for support and reinforcement, and the longitudinal spacing between adjacent I-beam inner supports 12 is 1m.

[0046] Step 3: Grouting Reinforcement of Crushed Carbonaceous Limestone: At locations beneath the crushed carbonaceous limestone 4 where there are karst caves 5, through cracks 8, and arched concrete pavement 7, a drilling rig is used to drill holes through the concrete pavement 7 to a certain depth beneath the crushed carbonaceous limestone 4. Several grouting pipes 15 are inserted into the holes in an array, with a longitudinal and transverse spacing of 1m x 1m. Cement grout is first injected into the holes through the grouting pipes 15, followed by a "cement grout + water glass" two-component grout. The water-cement ratio, water glass modulus, and concentration of the cement grout are determined through testing based on the severity of the damage (this invention only provides the construction process; specific parameters are designed based on the degree of crushing of the limestone at the construction site). The strength of the crushed carbonaceous limestone 4 is reinforced by filling the karst caves 5 and through cracks 8 through grouting.

[0047] Step 4: Remove Cracked and Heaved Concrete Pavement: In sections where the fractured carbonaceous limestone 4 is extremely fractured, with numerous through cracks 8 and significant heaving of the concrete pavement 7, and where grouting reinforcement is ineffective, excavate and remove the cracked and heaved concrete pavement 7. Also excavate and remove the fractured carbonaceous limestone 4 beneath the concrete pavement 7 to a certain depth. Each excavation cycle should be ≤3m long. Depending on the situation, use the inverted arch trestle for skip-slot excavation to increase the working face and improve construction efficiency. To prevent the tunnel from losing support, the surrounding rock 19 at the arch foot will be left unexcavated initially.

[0048] Step 5: Construction of the central section of the road surface arch: The arch 20 is poured in layers. After the arch 20 reaches a certain strength, an arc-shaped steel plate 21 with a matching curvature is placed on the arch 20, and the supporting steel frame 13 is supported on the arc-shaped steel plate 21.

[0049] Step 6: Construction of the invert arch at the arch foot: After the pressure of the surrounding rock around the tunnel is transferred to the invert arch 20 through the internal support of the I-beam 12 and the supporting steel frame 13, the surrounding rock 19 at the arch foot is removed, and the invert arch concrete at the arch foot is poured to connect the invert arch 20 with the initial support 1 and the concrete lining 3 to form a closed structure. After the concrete strength of the invert arch 20 reaches the design value, the supporting steel frame 13, the arc-shaped steel plate 21, the anchor bolt 14, and the internal support of the I-beam 12 are removed in sequence, the invert arch filling layer 22 is backfilled, and the cable trough 10 and drainage ditch 11 are restored.

[0050] Step 7, Installation of W steel strip: After the construction of the invert arch 20 and the invert arch filling layer 22 is completed, the pre-fabricated W steel strip 24 with anchor bolt reserved holes 27 is tightly attached to the cracked concrete lining 3. The W steel strip 24 is fixed to the surface of the concrete lining 3 with expanded bottom anchor bolts, and a ring of W steel strip 24 is set at every 1m interval.

[0051] Step 8: Grouting Anchor Installation: Drill grouting holes into the fractured surrounding rock 23 along the anchor holes 27 of the W steel strip 24. The grouting holes are arranged in a quincunx pattern. Insert the grouting anchors 26 into the grouting holes. Fix the ends of the grouting anchors 26 to the W steel strip 24. The circumferential spacing of the grouting anchors 26 is 2m. First, inject single-component cement grout into the grouting anchors 26, and then inject a double-component grout of "cement grout + water glass". The grouting parameters such as the water-cement ratio, water glass concentration, and grouting pressure are adjusted according to the actual site conditions.

[0052] Step Nine, Steel Fiber Reinforced Concrete Shotcrete: Lay a steel mesh on the surface of the W-shaped steel strip 24 with a mesh spacing of 20cm × 20cm. Add approximately 1% by volume of steel fibers (0.3mm-0.5mm in diameter and 10-15mm in length) to the concrete. Shotcrete 25, 12cm thick, onto the W-shaped steel strip 24 to seal it and the grouting anchor rods 26. After shotcreting the steel fiber reinforced concrete 25, apply polymer mortar to improve the appearance quality.

[0053] Step 10, Grooving the transverse expansion joint for seepage: Since the seepage joint 32 in the broken carbonaceous limestone 4 is connected to the transverse expansion joint 28 in the concrete pavement 7, resulting in a large number of seepage sections in the concrete pavement 7, a groove 30 is chiseled at the transverse expansion joint 28. The width and depth of the groove 30 are determined according to the amount of seepage.

[0054] Step 11: Install the channel steel: Thoroughly clean the groove 30. Make a standardized channel steel 29 according to the depth and width of the groove 30. Pre-embed the channel steel 29 in the groove 30, ensuring that the channel steel 29 presses on the seepage joint 32. Cut tongue and groove joints 37 on the drainage ditches 11 on both sides. Insert both ends of the channel steel 29 into the tongue and groove joints 37 of the drainage ditches 11. Set water baffles 33 at the ends of the channel steel 29 to seal and block water. Through the water guiding channel 36 in the channel steel 29, drain a large amount of water gushing from the seepage joint 32 into the drainage ditches 11 on both sides.

[0055] Step 12, Groove filling and leveling: Use waterproof geotextile 34 to fill the gaps on both sides of the channel steel 29, and cover the waterproof geotextile 34 with polymer mortar 35. After the surface of the polymer mortar 35 sealant is dry, use early-strength cement-based grout 31 to fill, compact and smooth the groove 30 to enhance the surface impermeability and restore the original state of the road surface. Perform appropriate maintenance according to the performance of the treatment materials to ensure that no cracks occur within a certain period of time.

[0056] This invention also discloses a system for treating arching defects in the pavement of operating tunnels located in underlying karst strata, such as... Figure 1 The diagram shows the structural principle of arching defects in the pavement of an operating tunnel in an underlying karst stratum. It includes initial support 1, reserved deformation allowance 2, concrete lining 3, fractured carbonaceous limestone 4, karst cave 5, water pressure 6, concrete pavement 7, through cracks 8, external thrust 9, cable trough 10, drainage ditch 11, and invert arch 20. The concrete pavement 7 in the operating tunnel does not have an invert arch 20. Beneath the concrete pavement 7 is fractured carbonaceous limestone 4, which contains localized karst caves 5. The accumulated water in the karst caves 5 generates water pressure 6, causing multiple through cracks 8 in the fractured carbonaceous limestone 4, simultaneously causing the concrete pavement 7 to bulge. This bulging of the concrete pavement 7 generates external thrust 9 on both sides, squeezing the concrete lining 3 and causing multiple cracks in the lining.

[0057] like Figure 2 The diagram shows the grouting reinforcement of the fractured rock layer under the road surface of the tunnel in the underlying karst strata. It includes fractured carbonaceous limestone 4, concrete road surface 7, through crack 8, grouting pipe 15, etc. The grouting pipe 15 passes through the concrete road surface 7 and is driven into the fractured carbonaceous limestone 4 to a certain depth (the depth is generally the fractured carbonaceous limestone and the bottom of the karst cave). The through crack 8 is repaired and reinforced by injecting cement grout + water glass dual liquid grout.

[0058] like Figures 2-3The enlarged view of the bottom installation and fixing structure of the arc-shaped I-beam internal support steel frame shown includes a concrete lining 3, a cable trough 10, an I-beam internal support 12, a bracing steel frame 13, a locking anchor rod 14, a longitudinal steel lifting beam 16, an adjustable support 17, and a supporting steel plate 18. The I-beam internal supports 12 are installed inside the partially cracked concrete lining 3 for pre-reinforcement. The I-beam internal supports 12 are circumferential internal support structures, closely attached to the concrete lining 3, with a longitudinal spacing of 1m. After the cable trough 10 is removed from the foot of the inner support 12 of the I-beam, a longitudinal steel lifting beam 16 is installed. The longitudinal steel lifting beam 16 rests on the support steel plate 18. Multiple adjustable supports 17 are provided at the lower part of the support steel plate 18. The height and tightness of the inner support 12 of the I-beam can be adjusted by the adjustable supports 17. The foot of the inner support 12 of the I-beam is locked by the locking anchor rod 14. A counter-bracing steel frame 13 is installed inside the arch of the inner support 12 of the I-beam for counter-bracing and reinforcement.

[0059] The adjustable support 17 can adopt a jack structure to adjust the height of the supporting steel plate 18, thereby adjusting the height of the longitudinal steel lifting beam 16 and the feet of the I-beam inner support 12. After the adjustment is completed, it is then locked by the foot anchor rod 14.

[0060] like Figure 4 The diagram shows the pre-reinforcement excavation and casting of the intermediate invert arch structure for the operating tunnel in the underlying karst strata. It includes broken carbonaceous limestone 4, concrete pavement 7, surrounding rock 19 at the arch foot, and invert arch 20. When the raised concrete pavement 7 is removed, the central part of the pavement is removed first, and then removed from the middle to both sides. At the same time, the broken carbonaceous limestone 4 under the concrete pavement 7 is removed to a certain depth (generally the design depth of the invert arch). The surrounding rock 19 at the arch foot is not removed first. The invert arch 20 is set after the raised concrete pavement 7 is removed.

[0061] like Figures 5-7 The diagram shows the pre-reinforcement structure of the tunnel operating in the underlying karst strata, which transmits force to the intermediate invert arch. It includes a concrete lining 3, an I-beam internal support 12, a supporting steel frame 13, surrounding rock at the arch foot 19, an invert arch 20, an arc-shaped steel plate 21, and an invert arch filling layer 22. An arc-shaped steel plate 21 with matching curvature is placed on the invert arch 20, and the supporting steel frame 13 is erected on the arc-shaped steel plate 21. The supporting steel frame 13 transmits the tunnel surrounding rock pressure to the invert arch 20. Then, the surrounding rock 19 at the arch foot is removed, and concrete is poured at the arch foot to form a closed structure for the invert arch 20. After the invert arch 20 and the concrete lining 3 form a closed loop, the I-beam internal support 12, the supporting steel frame 13, and other pre-reinforcement structures are removed, the invert arch filling layer 22 is backfilled, and the cable trough 10 and drainage ditch 11 are restored.

[0062] like Figures 7-8The diagram shows a combined reinforcement structure for an operating tunnel in an underlying karst stratum, consisting of a W-shaped steel strip, anchor bolt grouting, and shotcrete. This includes a concrete lining 3, fractured surrounding rock 23, a W-shaped steel strip 24, steel fiber concrete 25, grouting anchor bolts 26, and anchor bolt pre-drilled holes 27. The cracked concrete lining 3 is reinforced using a combination of W-shaped steel strip, anchor bolt grouting, and shotcrete. The W-shaped steel strips 24 are circumferentially fixed to the surface of the concrete lining 3 by anchor bolts, with a longitudinal spacing of 1m. Multiple pre-drilled anchor holes 27 are pre-drilled in a plum blossom pattern on the 24. The grouting anchor 26 passes through the pre-drilled anchor holes 27 and is driven into the broken surrounding rock 23 for grouting reinforcement. The circumferential spacing of the grouting anchor 26 is 2m. The grouting anchor 26 is first injected with single-component cement grout, and then injected with a double-component grout of "cement grout + water glass". Steel fiber reinforced concrete 25 is sprayed onto the W steel strip 24 for sealing. The thickness of the steel fiber reinforced concrete 25 sprayed is between 12-15cm. The surface of the steel fiber reinforced concrete 25 is plastered with polymer mortar.

[0063] like Figures 9-11 The diagram shows a transverse expansion joint groove embedded in a channel steel in an operating tunnel with seepage. It includes fractured carbonaceous limestone 4, concrete pavement 7, an invert 20, a transverse expansion joint 28, a channel steel 29, and a groove 30. The concrete pavement 7 does not have an invert 20 underneath. The fractured carbonaceous limestone 4 beneath a portion of the concrete pavement 7 has multiple seepage joints 32. These joints extend from the fractured carbonaceous limestone 4 into the concrete pavement 7 and connect with the transverse expansion joint 28, forming a channel for water to overflow onto the pavement. A groove 30 is chiseled downwards at the transverse expansion joint 28 of the concrete pavement 7. The width and depth of the groove 30 are determined based on the amount of seepage.

[0064] like Figures 10-12 The diagram shows a detailed installation of a channel steel and waterproof structure within a groove at the transverse expansion joint of the road surface. This includes a drainage ditch 11, early-strength cement-based grouting material 31, a seepage joint 32, a water-retaining plate 33, waterproof geotextile 34, polymer mortar 35, a water-guiding channel 36, and a tongue-and-groove joint 37. A channel steel 29 is placed in the center of the groove 30, pressing against the seepage joint 32. The channel steel 29 extends transversely along the road surface. A tongue-and-groove joint 37 is provided on the drainage ditch 11. The end is inserted into the tongue and groove 37; waterproof geotextile 34 is first laid in the gap on both sides of the channel steel 29, and then polymer mortar 35 is poured in. The two ends of the channel steel 29 are connected to the drainage ditch 11. Water baffles 33 are set at the ends of the channel steel 29 to block water. The closed water guiding channel 36 formed by the channel steel 29 guides the water flowing out of the seepage crack 32 to the drainage ditch 11 on both sides for discharge. The top of the groove 30 is filled with early-strength cement-based grout 31 and compacted and smoothed.

[0065] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A construction method of a karst cave stratum tunnel pavement arching disease treatment system, characterized in that, The method comprises the following steps: Step one, construction preparation: using geological radar detection equipment, seismic surface wave exploration equipment, crack depth and width detection equipment to detect and mark the number and location of karst cave (5) and through cracks (8) in broken carbonaceous limestone (4), the location and number of concrete pavement (7) cracking and upheaval, the number and water seepage amount of water seepage joint (32), the crack depth and number of concrete lining (3), and the number of hollowing, underpropping and voiding diseases between concrete lining (3) and reserved deformation (2); Step two, lining pre-reinforcement: removing cable trough (10), chiseling out local broken carbonaceous limestone (4) at arch foot, cleaning stone debris and leveling, then assembling arc I-beam inner support (12) into a ring, I-beam inner support (12) closely adheres to concrete lining (3), after adjusting the position and tightness of I-beam inner support (12), locking foot anchor rod (14) is used to lock the foot of I-beam inner support (12); Step three, broken carbonaceous limestone grouting reinforcement: drilling a hole through concrete pavement (7) to a certain depth below broken carbonaceous limestone (4) at the place where concrete pavement (7) is arched, inserting a plurality of grouting pipes (15) in array distribution into the hole, filling cement single slurry into the hole through grouting pipe (15), then filling "cement slurry + water glass" double slurry into the hole, filling karst cave (5) and through cracks (8) through grouting to reinforce the strength of broken carbonaceous limestone (4); Step four, chiseling out cracked and upheaved concrete pavement: when the grouting reinforcement effect is poor, excavating and chiseling out cracked and upheaved concrete pavement (7) and excavating and chiseling out broken carbonaceous limestone (4) to a certain depth under concrete pavement (7), without excavating and chiseling out surrounding rock (19) at arch foot; Step five, construction of central part of pavement inverted arch: pouring inverted arch (20) in layers, placing arc steel plate (21) with matching arc on inverted arch (20) after the strength of inverted arch (20) reaches a certain value; Step six, construction of inverted arch at arch foot: after the surrounding rock pressure of tunnel is transmitted to inverted arch (20), chiseling out surrounding rock (19) at arch foot, pouring inverted arch concrete at arch foot to make inverted arch (20) communicate with primary support (1) and concrete lining (3) to form closed structure, then sequentially removing counter-bracing steel frame (13), arc steel plate (21), locking foot anchor rod (14) and I-beam inner support (12), backfilling inverted arch filling layer (22), and restoring cable trough (10) and drainage ditch (11); Step seven, W steel belt installation: after the construction of inverted arch (20) and inverted arch filling layer (22) is completed, W steel belt (24) with anchor rod reserved hole (27) is closely adhered to cracked concrete lining (3), and W steel belt (24) is fixed on the surface of concrete lining (3); Step eight, grouting anchor rod installation: along the anchor rod reserved hole (27) of W steel belt (24) to drill grouting hole in broken surrounding rock (23), grouting hole is arranged in the shape of plum blossom, grouting anchor rod (26) is inserted into grouting hole, end of grouting anchor rod (26) is fixed on W steel belt (24), grouting anchor rod (26) is first injected cement single slurry, then "cement slurry + water glass” double slurry is injected; Step nine, steel fiber concrete spraying: steel mesh is laid on the surface of W steel belt (24), steel fiber concrete (25) is sprayed on W steel belt (24), W steel belt (24) and grouting anchor rod (26) are closed, after spraying steel fiber concrete (25), polymer mortar is used for finishing; Step ten, groove of water seepage transverse expansion joint: for the communication between water seepage joint (32) in broken carbonaceous limestone (4) and transverse expansion joint (28) in concrete pavement (7), a large number of seepage water appears in concrete pavement (7), groove (30) is chiseled at transverse expansion joint (28); Step eleven, installation of channel steel: channel steel (29) is pre-buried and installed in groove (30), and it is ensured that channel steel (29) is pressed on water seepage joint (32); Step twelve, groove filling and leveling: waterproof geotextile (34) is used to fill the gap between both sides of channel steel (29), polymer mortar (35) is used to cover waterproof geotextile (34), after the surface of polymer mortar (35) is dried, early strength cement-based grouting material (31) is used to fill and compact and level the groove (30), and the original state of the pavement is restored.

2. The method of claim 1, wherein the method further comprises: providing a tunnel pavement crown lifting system; and installing the tunnel pavement crown lifting system in the tunnel. In step two, after the stone slag is cleaned and leveled, adjustable support (17) is erected, support steel plate (18) is placed on adjustable support (17), longitudinal steel joist (16) is placed on support steel plate (18), foot of I-steel inner support (12) is supported on longitudinal steel joist (16), counter-bracing steel frame (13) is arranged in the ring of I-steel inner support (12) to support and reinforce, and the longitudinal distance between adjacent I-steel inner supports (12) is 1 m.

3. The method of claim 1, wherein the method further comprises: providing a plurality of support members; and positioning the plurality of support members in the cavity. In step three, the longitudinal and transverse distance between grouting pipes (15) is 1 m*1 m.

4. The method of claim 1, wherein the method further comprises: providing a tunnel pavement crown lifting system; and installing the tunnel pavement crown lifting system in the tunnel. In step four, the broken carbonaceous limestone (4) under the concrete pavement (7) is excavated and removed every cycle excavation length ≤ 3 m.

5. The method of claim 2, wherein the method further comprises: providing a plurality of the tunnel floor arching systems; and positioning the plurality of the tunnel floor arching systems in the tunnel floor. The counter-bracing steel frame (13) is supported on the arc-shaped steel plate (21).

6. The method of claim 1, wherein the method further comprises: In step seven, one ring of W steel belt (24) is arranged every 1 m.

7. The method of claim 1, wherein the method further comprises: providing a tunnel pavement crown lifting system; and installing the tunnel pavement crown lifting system in the tunnel. In step eight, the circumferential distance between grouting anchor rods (26) is 2 m.

8. The method of claim 1, wherein the method further comprises: providing a tunnel pavement crown lifting system; and installing the tunnel pavement crown lifting system in the tunnel. In step nine, the grid spacing is 20 cm*20 cm, 1% of steel fiber is mixed in the concrete, the diameter of the steel fiber is 0.3 mm-0.5 mm, the length is 10-15 mm, and the thickness of the steel fiber concrete (25) is 12 cm.

9. The method of claim 1, wherein the method further comprises: providing a tunnel pavement crown lifting system; and installing the tunnel pavement crown lifting system in the tunnel. In step eleven, notches (37) are cut on the drainage ditches (11) on both sides of the channel steel (29), the channel steel (29) is inserted into the notches (37) of the drainage ditches (11), the water baffle (33) is arranged at the port of the channel steel (29) to close and block water, and the water seepage joint (32) is drained into the drainage ditches (11) on both sides through the water guide channel (36) in the channel steel (29).

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