Tunnel lining prefabricated segment grouting hole leakage water plugging device and method

Abstract

The invention discloses a tunnel lining prefabricated segment grouting hole leakage water plugging device and method, and belongs to the technical field of tunnel and underground engineering waterproofing. The device comprises a bolt fixing layer, a locking sealing layer and a sealing protection layer, the bolt fixing layer comprises a high-strength bolt, the locking sealing layer comprises a taper locking block, an elastic steel sleeve and a fixing base, and the sealing protection layer comprises ethylene propylene diene monomer; the high-strength bolt penetrates through the taper locking block, the elastic steel sleeve and the fixing base, the taper locking block is embedded into the elastic steel sleeve, when the high-strength bolt is screwed down, the taper locking block extrudes the elastic steel sleeve in the radial direction, the EPDM rubber sleeve is pushed to be tightly attached to the concrete prefabricated segment, and the elastic steel sleeve is covered with the EPDM rubber sleeve. Gaps around the grouting holes are filled through elastic deformation, and pressure resistance and water resistance are achieved. The method solves the problem of leakage caused by insufficient locking, poor material performance and rough construction in the prior art, and is suitable for high confined water head and complex stratum environments.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel and underground engineering waterproofing, and in particular to a device and method for sealing water leakage in grouting holes of prefabricated pipe segments of a tunnel lining. Background Art

[0002] As core components of shield tunneling, precast tunnel lining segments play a crucial role in resisting ground pressure, groundwater infiltration, and external loads. Grouting holes are key structures used for backfill grouting after segment installation. The quality of their sealing directly impacts the overall waterproofing performance and structural stability of the tunnel. However, in actual projects, grouting hole sealing often faces the following technical challenges: 1. The impact of complex geological conditions: Taking the Jingxi Road to Baiyun Dongping section of the Guangzhou East to Huadu Tiangui Intercity Railway as an example, the tunnel project must pass through a full section of hard rock (rock strength exceeding 200 MPa), a fractured zone, and a composite stratum with soft upper and hard lower layers. The high pressure head (maximum burial depth exceeding 210 meters) makes it easy for the grouting holes to be penetrated by water pressure after being sealed, causing leakage.

[0003] 2. Limitations of traditional plugging materials: Conventional plugging mortars have large shrinkage and insufficient bonding strength (e.g., compressive strength <60 MPa, bonding strength <1.5 MPa). They are prone to peeling off from the segment interface under high-pressure conditions, forming water seepage channels.

[0004] 3. Construction process defects: The existing sealing device lacks an effective locking and elastic sealing structure, resulting in a loose fit between the sealing mechanism and the inner wall of the grouting hole, making it difficult to fill the tiny gaps around the hole, and the surface is uneven after sealing, affecting durability.

[0005] Furthermore, in the later stages of shield tunneling, residual cement and stone in the grouting holes can hinder the installation of sealing devices, further exacerbating the risk of leakage. While existing technologies have attempted to combine mechanical fixation with mortar filling, limitations in material properties and structural design have prevented leakage in high-pressure water environments.

[0006] Therefore, there is an urgent need for a sealing device and method that has high pressure resistance, elastic sealing and reliable locking functions to cope with the challenge of water leakage in the grouting holes of prefabricated pipe segments in tunnel linings under complex geological conditions. Summary of the Invention

[0007] The purpose of the present invention is to provide a device and method for sealing water leakage in the grouting holes of prefabricated pipe segments of tunnel lining, so as to solve the technical problem of leakage in the grouting holes of prefabricated pipe segments of tunnel lining under complex geological conditions due to high-pressure water penetration, large shrinkage of traditional sealing materials and defects in construction technology.

[0008] To achieve the above objectives, the present invention provides the following technical solutions: In the first aspect, the present invention provides a water leakage sealing device for grouting holes of prefabricated pipe segments in a tunnel lining, comprising a bolt fixing layer, a locking sealing layer and a sealing protective layer connected in sequence, wherein the bolt fixing layer comprises high-strength bolts, the locking sealing layer comprises a tapered locking block, an elastic steel sleeve and a fixing seat, and the sealing protective layer comprises EPDM rubber; the high-strength bolts pass through the tapered locking block, the elastic steel sleeve and the fixing seat, and the tapered locking block is embedded in the elastic steel sleeve. When the high-strength bolts are tightened, the tapered locking block radially squeezes the elastic steel sleeve, pushing the EPDM rubber sleeve to fit tightly with the concrete prefabricated pipe segment, and the EPDM rubber sleeve covers the outside of the elastic steel sleeve, and fills the gaps around the grouting holes through elastic deformation to achieve pressure resistance and water resistance.

[0009] Furthermore, the high-strength bolt and the tapered locking block are provided with a gasket assembly, and the gasket assembly includes a flat washer and a spring washer.

[0010] In a second aspect, the present invention provides a method for sealing water leakage in grouting holes of prefabricated tunnel lining segments, comprising the following steps: Step 1: Clean the grouting hole: Use the drill bit to clean the hole to remove the cement stones remaining in the grouting hole; Step 2: Install the in-hole sealing mechanism: Insert the in-hole sealing mechanism into the grouting hole, rotate the screw to clamp the bottom steel plate fixing seat and the tapered locking block to the inner wall of the hole, and fix it with a wrench at the hole opening; Step 3: Fill with non-shrinkage sealing mortar: Backfill the non-shrinkage sealing mortar to the grouting hole in layers, with a thickness of 2 cm for each layer, and tamp it with a wooden stick. When the backfill depth reaches the threaded pipe section in the hole, place the fixed gasket in the hole, remove the hole fixing wrench, and gradually backfill to the hole mouth to complete the construction; Step 4: Maintenance and surface treatment: After the plugging is completed, maintain the material for 7 days and polish the hole to ensure a smooth surface.

[0011] Furthermore, in step 1, the drill bit used for cleaning the hole opening is a Ø18mm twist drill bit with a length of 600mm, and four 20mm long side drill bits are installed at the end thereof.

[0012] Furthermore, in step 2, the hole fixing wrench includes a screw at one end with a nut and a T-shaped handle at the other end, with the screw running across the middle; by tightening the screw, the tapered locking block squeezes the elastic steel sleeve, driving the EPDM rubber sleeve to fit tightly against the pipe segment.

[0013] Furthermore, in step 3, the ratio of the non-shrinkage sealing mortar is 160 kg of water, 612 kg of cement, 1468 kg of quartz sand, 2.76 kg of water reducer, 0.22 kg of expansion agent, and 0.12 kg of air entraining agent, with a compressive strength of ≥60 MPa and a bonding strength of ≥1.5 MPa.

[0014] Based on the above technical solution, the embodiments of the present invention can produce at least the following technical effects: (1) The present invention provides a device for sealing water leakage in grouting holes of prefabricated segments of tunnel linings. The present invention adopts the coordinated design of a bolt fixing layer, a locking sealing layer and a sealing protective layer. The device uses high-strength bolts to drive a tapered locking block to radially extrude an elastic steel sleeve, forcing the EPDM rubber sleeve to elastically deform to fill the gap around the hole, thereby achieving reliable sealing under high-pressure conditions.

[0015] (2) The present invention provides a method for sealing water leakage in grouting holes of prefabricated tunnel lining segments, which, in combination with a layered backfilling process using non-shrinkage sealing mortar (compressive strength ≥ 60 MPa, bonding strength ≥ 1.5 MPa), effectively suppresses material shrinkage and interface peeling. The construction method uses specialized tools to precisely install the sealing mechanism, combined with in-hole cleaning, layered compaction, and maintenance processes, to significantly improve the sealing density and durability. This solves the leakage problems caused by insufficient tightening, poor material properties, and rough construction in traditional technologies, and is suitable for high-pressure head and complex stratum environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0017] Figure 1 It is a structural diagram of an embodiment of the present invention; In the figure: 1. High-strength bolt; 2. Gasket assembly; 3. Tapered locking block; 4. Elastic steel sleeve; 5. Fixed seat; 6. EPDM rubber sleeve. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below. 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 without making creative work are within the scope of protection of the present invention. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0019] Example 1 like Figure 1As shown, the present invention provides a device for sealing water leakage in grouting holes in prefabricated tunnel lining segments. The device comprises: a high-strength bolt 1, made of M20 high-strength alloy steel, galvanized for rust prevention, with a tensile strength of ≥800 MPa, used to penetrate and secure each layer of the structure. A gasket assembly 2, consisting of a flat washer (3 mm thick) and a spring washer (65Mn spring steel) with an adjustable preload force to prevent loosening. A tapered locking block 3, made of 45# steel with an 8° taper angle and an outer diameter tapering from Ø75mm to Ø70mm. The block is surface-hardened and has a hardness of HRC 45-50. An elastic steel sleeve 4, made of 304 stainless steel with a 2 mm wall thickness and an outer diameter of Ø70mm, has an inner diameter matching the tapered locking block and features four 2 mm wide axial slots to enhance radial elastic deformation. A fixing base 5, consisting of a Ø63 mm circular steel plate with a thickness of 10 mm and a central hole for a screw rod, is used to secure the inner wall of the grouting hole. EPDM rubber sleeve 6: outer diameter Ø80mm, thickness 5mm, Shore hardness 60±5, pressure resistance ≥1.5MPa, anti-aging performance in line with GB / T 3512 standard, covers the outside of the elastic steel sleeve and fills the gap around the hole through elastic deformation.

[0020] Installation process: Insert the high-strength bolt 1 sequentially through the tapered locking block 3, the elastic steel sleeve 4, and the fixing seat 5, and install the gasket assembly 2 on the bolt head. Then, insert the assembled sealing mechanism into the grouting hole and rotate the screw to lock the fixing seat 5 and the tapered locking block 3 against the inner wall of the hole. Finally, tighten the screw with the hole-fixing wrench. The tapered locking block 3 radially compresses the elastic steel sleeve 4, forcing the EPDM rubber sleeve 6 to tightly fit against the inner wall of the segment, forming a preliminary seal.

[0021] Example 2 The present invention provides a method for sealing water leakage in grouting holes of prefabricated tunnel lining segments, comprising the following steps: Step 1: Clean the grouting holes The cement slurry stones left in the grouting hole from the previous grouting process affect the installation of this device. A 600mm long Ø18mm twist drill bit with four 20mm long lateral drill bits installed on the end is used to remove the residual cement stones in the hole. When drilling, the drill bit axis is kept consistent with the grouting hole to avoid damaging the hole wall. After cleaning, a high-pressure air gun is used to blow away the debris.

[0022] Step 2: Install the hole sealing mechanism The orifice fixing wrench consists of a 20mm long Ø8mm screw with an inner diameter of Ø8mm and a nut at the end, 180mm long. The other end is a T-shaped handle, with a 140mm long screw running through the middle. When used, the handle is held in place. When tightened, the tapered locking block presses inward, causing the elastic steel sleeve to expand. This allows the outer layer of the pressure-resistant, flame-retardant, and anti-aging EPDM rubber sleeve to tightly bond with the precast concrete segment, achieving a waterproof effect.

[0023] The hole plugging mechanism is composed of a 280mm long 8mm diameter screw rod and a fixed seat, and the structure from the bottom to the top of the screw rod is: bottom end, 63mm diameter hole steel plate fixed seat, 75mm diameter hole taper locking block, 70mm diameter elastic steel sleeve, 80mm diameter pressure-resistant, flame-retardant and anti-aging EPDM rubber sleeve. During construction, the bottom end hole steel plate fixed seat, hole taper locking block, elastic steel sleeve, and pressure-resistant, flame-retardant and anti-aging EPDM rubber sleeve are arranged in order, the screw rod is rotated into the hole, and the bottom steel plate fixed seat and the hole taper locking block are rotated to be clamped on the inner side of the hole, then the plugging device is fixed in the hole using a special tool wrench to place it flat, and the non-shrinkage plugging mortar backfilling is started.

[0024] Step 3: filling non-shrinkage plugging mortar The non-shrinkage plugging mortar is mixed according to the following mixing ratio: water 160Kg, cement 612Kg (P.O 42.5), quartz sand 1468Kg (particle size 0.3-0.6mm), water reducing agent 2.76Kg (polycarboxylic acid type), expanding agent 0.22Kg (UEA type), and air entraining agent 0.12Kg (rosin type).

[0025] The compressive strength of the non-shrinkage plugging mortar is ≥60Mpa, and the bonding strength is ≥1.5MPa. After the mortar is mixed, it is held into a ball, and it can be scattered when the hand is loose, which is the best. The backfilling thickness of each layer is 2cm, and a wooden rod is used for tamping. When the backfilling depth reaches the threaded pipe segment in the hole, the hole fixed washer is placed, the special wrench is withdrawn, and the backfilling is gradually completed to the hole opening.

[0026] Step 4: curing and surface treatment After plugging is completed, wet cloth is covered for curing for 7 days, the environmental temperature is maintained at 20±5℃, and the humidity is ≥90%. After curing is completed, an angle grinder (grinding wheel particle size 80 mesh) is used to polish the hole opening, so that the surface flatness error is ≤1mm, and it is consistent with the appearance of the pipe segment.

[0027] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A device for plugging water leakage in grouting holes of prefabricated tunnel lining segments, characterized in that: The invention comprises a bolt fixing layer, a locking sealing layer and a sealing protection layer connected in sequence, wherein the bolt fixing layer comprises a high-strength bolt (1), the locking sealing layer comprises a tapered locking block (3), an elastic steel sleeve (4) and a fixing seat (5), and the sealing protection layer comprises EPDM rubber (6); the high-strength bolt (1) passes through the tapered locking block (3), the elastic steel sleeve (4) and the fixing seat (5), and the tapered locking block (3) is embedded in the elastic steel sleeve (4); when the high-strength bolt (1) is tightened, the tapered locking block (3) radially presses the elastic steel sleeve (4), pushing the EPDM rubber sleeve (6) to fit tightly with the concrete prefabricated pipe segment, and the EPDM rubber sleeve (6) covers the outside of the elastic steel sleeve (4), and fills the gap around the grouting hole through elastic deformation, thereby achieving pressure resistance and water resistance.

2. The device for plugging water leakage in grouting holes of prefabricated tunnel lining segments according to claim 1 is characterized in that: The high-strength bolt (1) and the tapered locking block are provided with a gasket assembly (2), and the gasket assembly comprises a flat gasket and a spring gasket.

3. A method for sealing water leakage in grouting holes of prefabricated tunnel lining segments, characterized in that: The following steps are involved: Step 1: Clean the grouting hole: Use the drill bit to clean the hole to remove the cement stones remaining in the grouting hole; Step 2: Install the in-hole sealing mechanism: Insert the in-hole sealing mechanism into the grouting hole, rotate the screw to clamp the bottom steel plate fixing seat and the tapered locking block to the inner wall of the hole, and fix it with a wrench at the hole opening; Step 3: Fill with non-shrinkage sealing mortar: Backfill the non-shrinkage sealing mortar to the grouting hole in layers, with a thickness of 2 cm for each layer, and tamp it with a wooden stick. When the backfill depth reaches the threaded pipe section in the hole, place the fixed gasket in the hole, remove the hole fixing wrench, and gradually backfill to the hole mouth to complete the construction; Step 4: Maintenance and surface treatment: After the plugging is completed, maintain the material for 7 days and polish the hole to ensure a smooth surface.

4. The method for sealing water leakage in grouting holes of prefabricated tunnel lining segments according to claim 3, characterized in that: In step 1, the drill bit used for cleaning the hole opening is a Ø18mm twist drill bit with a length of 600mm, and four 20mm long side drill bits are installed at the end thereof.

5. The method for sealing water leakage in grouting holes of prefabricated tunnel lining segments according to claim 3, characterized in that: In step 2, the hole fixing wrench includes a screw at one end with a nut and a T-shaped handle at the other end, with the screw running across the middle; by tightening the screw, the tapered locking block squeezes the elastic steel sleeve, driving the EPDM rubber sleeve to fit tightly against the pipe segment.

6. The method for sealing water leakage in grouting holes of prefabricated tunnel lining segments according to claim 3, characterized in that: In step 3, the ratio of the non-shrinkage sealing mortar is 160 kg of water, 612 kg of cement, 1468 kg of quartz sand, 2.76 kg of water reducer, 0.22 kg of expansion agent, and 0.12 kg of air entraining agent. The compressive strength is ≥60 MPa and the bonding strength is ≥1.5 MPa.

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