An expansion anchor drainage device for TBM and a construction method thereof

Abstract

The application discloses a TBM expansion anchoring water discharge device and a construction method thereof, and solves the problems that the existing water discharge hole structure lacks reliable anchoring and sealing, cannot form a stable subsequent operation channel, and is difficult to independently open and close and adjust the drainage state according to the construction requirement. The TBM expansion anchoring water discharge device comprises an anchoring water discharge assembly, the anchoring water discharge assembly comprises an expansion sleeve and a hollow screw rod arranged in the expansion sleeve, and a central through hole in the hollow screw rod is a drill rod channel or a water flow channel; when the central through hole is the water flow channel, a ball valve is threadedly connected to the rear end of the hollow screw rod. The application not only guarantees the stability of the water discharge channel, avoids the collapse or blockage of the orifice of the traditional bare hole caused by the deformation of surrounding rock or seepage scouring, but also forms effective sealing by the close fit of the expansion section and the hole wall, prevents the leakage of underground water along the periphery of the sleeve, and significantly improves the long-term reliability of the water discharge hole.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to a tunnel drainage device. Background Technology

[0002] In open-face TBM construction, groundwater hazards are one of the major challenges faced during both construction and operation phases. When operating in hard rock formations, especially in water-rich areas, pressurized groundwater often exists within rock fissures. If not properly managed, the high water pressure can easily lead to cracking, spalling, or even water inrush in the initial support shotcrete layer, seriously threatening construction safety and project quality. To address this issue, installing drainage holes to drain water behind the support structure and reduce water pressure has become a standard treatment method in TBM construction.

[0003] Currently, the conventional approach for tunnel drainage holes is to directly drill holes into the rock mass to form drainage channels after the shotcrete support is completed, or to pre-embed drainage pipes during secondary lining construction. However, the former involves exposed holes, making it impossible to achieve controllable opening and closing and flow regulation, and it is also difficult to provide an effective channel for later operations such as grouting and sealing. The latter approach, such as the "Drainage Hole Structure for Tunnel Lining Sidewall" disclosed in patent application publication number CN111810233A, can achieve water diversion through drainage pipes pre-embedded in the secondary lining, but its construction process is complex, requiring precise positioning before pouring the secondary lining, and the structure does not have an anchoring function, nor can it be quickly installed simultaneously with TBM construction during the initial support stage. In addition, patent application publication number CN115584726A describes "A Grouting-Type Expansion Anchor Rod and Anchoring Method," which discloses an anchor rod including a hollow grouting rod body, an external expansion device, and a pressure rod. Although this scheme describes the anchoring method, it mainly relies on mortar solidification to achieve the anchoring effect. Its core function is limited to rock mass reinforcement and grouting operations. These devices lack ball valve control structures, cannot be actively opened and closed or have flow rate regulation, and are difficult to quickly install as drainage holes and form controllable drainage channels in the "spray before drilling" TBM tunnel construction process. Therefore, developing a drainage device and construction method that is adaptable to TBM construction procedures, has a simple structure, integrated functions, and can be actively controlled has significant engineering practical value. Summary of the Invention

[0004] To address the shortcomings in the aforementioned background technology, this invention proposes an expansion anchor drainage device for TBMs and its construction method, which solves the problems of existing drainage hole structures lacking reliable anchoring and sealing, failing to form a stable subsequent operation channel, and being difficult to autonomously open, close, and adjust the drainage status according to construction needs.

[0005] The technical solution of this invention is implemented as follows: An expansion anchoring drainage device for TBMs includes an anchoring drainage component, which includes an expansion sleeve and a hollow screw rod disposed within the expansion sleeve. The central through hole inside the hollow screw rod serves as a drill rod channel or a water flow channel. When the central through hole serves as a water flow channel, a ball valve is threadedly connected to the rear end of the hollow screw rod. In the technical solution of this invention, by combining the expansion anchoring mechanism with the hollow channel, two key technical principles are achieved: First, by utilizing the mechanical anchoring force of the expansion sleeve, a reliable connection is formed between the device and the tunnel wall, which not only solves the problem of exposed and unprotected conventional drainage holes but also provides a stable interface for subsequent operations of the hollow channel; Second, by adopting a step-by-step construction method of "casing anchoring first, drill rod secondary drilling," the stability and sealing of the borehole opening section during drilling are ensured, and the drill rod can be precisely extended to the target aquifer.

[0006] Further preferably, the expansion sleeve comprises, from front to back, an expansion section, a connecting section, and a flange. The outer wall of the expansion section is provided with several expansion flaps; a sealing sleeve is fitted onto the outer wall of the connecting section. This invention not only ensures the stability of the drainage channel, avoiding the collapse or blockage of the orifice caused by surrounding rock deformation or seepage erosion in traditional open boreholes, but also provides an effective seal through the tight fit between the expansion section and the borehole wall, preventing groundwater leakage along the perimeter of the casing and significantly improving the long-term reliability of the drainage hole.

[0007] Further preferred, the hollow screw includes, from front to back, a tapered tail section, a smooth section and a threaded section. The threaded section extends out of the flange and is driven forward by a nut that is threadedly connected to the threaded section. The tapered tail section expands the expansion section of the expansion sleeve.

[0008] Further optimization involves using the central through-hole as a drill rod channel, through which the drill rod penetrates the rock mass until it reaches the aquifer to form a drainage hole. Further optimization also allows the central through-hole to function as a water flow channel after the drill rod is withdrawn. Further optimization further allows the central through-hole to also serve as a grouting and sealing channel or a water pressure monitoring channel. The central through-hole inside the hollow screw rod serves sequentially as a drill rod channel, water flow channel, grouting and sealing channel, or water pressure monitoring channel according to the construction stage, achieving a high degree of integration with multiple uses. After the drill rod is withdrawn, the original channel immediately becomes a water flow channel, eliminating the need for secondary hole cleaning and pipe lowering, thus eliminating the potential for hole wall disturbance and channel blockage caused by repeated insertion and removal in traditional solutions.

[0009] A construction method based on the above-mentioned TBM expansion anchor drainage device includes the following steps: S1 Drilling a primary hole: On the surface of the initial support layer of the TBM tunnel, a pre-drilled hole of a certain depth is drilled using a first drill bit; S2 Mechanical anchoring: The anchor drainage component is inserted into the pre-drilled hole, and a nut is pre-installed on the hollow screw. By rotating the nut, the hollow screw is pushed forward, causing the hollow screw to expand the expansion sleeve and the expansion section of the expansion sleeve to be tightly embedded in the hole wall, thus achieving mechanical anchoring; S3 Drilling a drainage hole: The drill rod is inserted into the central through hole of the hollow screw and drilled into the rock mass until it penetrates to the aquifer, forming a drainage hole; S4 Installing a ball valve: After the drainage hole is drilled, the drill rod is withdrawn from the central through hole, and then a ball valve is installed on the threaded section at the rear end of the hollow screw to form a drainage channel with controllable opening.

[0010] In step S2, a sealing sleeve is fitted on the hollow screw of the anchoring drainage component. The sealing sleeve expands when it comes into contact with water and plays a sealing role after mechanical anchoring to prevent groundwater from leaking out from the outer gap of the pipe sleeve.

[0011] In step S2, when the anchoring drainage component is inserted into the pre-drilled hole, a wedge-shaped pad is placed between the surface of the initial support layer and the flange of the expansion sleeve.

[0012] In step S4, remove the nut before installing the ball valve; during subsequent construction, adjust the opening of the ball valve as needed; before pouring the secondary lining, close the ball valve to perform back grouting to prevent grout loss; during operation, when the water pressure is too high, open the ball valve to release the water pressure to avoid the lining being subjected to excessive water pressure.

[0013] The beneficial effects of this invention are as follows: This invention solves the problems of insufficient anchoring force and easy loosening and detachment in traditional drainage hole structures through expansion mechanical anchoring; it solves the problems of complex multi-process conversion and easy channel blockage through the multi-functional reuse of the central through-hole; it solves the problems of hole wall leakage and sealing failure through the synergy of the sealing sleeve and expansion structure; and it solves the problems of uncontrollable drainage and inability to adjust as needed through external ball valve control. The overall solution achieves a comprehensive leap in the structural reliability, construction convenience, functional integration, and operational controllability of TBM drainage devices, and is particularly suitable for TBM tunnel construction environments with high pressure, abundant water, limited space, and compact processes, possessing significant engineering practical value and promising prospects for promotion.

[0014] This construction method solves the problems of difficult drainage hole positioning and duct deviation by using pre-drilling for precise guidance; it addresses the issues of long anchoring and curing time and unstable drilling process in traditional methods by reversing the process of anchoring before drilling; it solves the problems of easy hole collapse and complex process transitions during secondary pipe laying by using integrated drilling of the central through hole; and it solves the problems of uncontrollable drainage and inflexible subsequent handling by using a ball valve that can be installed and used immediately at the rear. The four steps are interconnected and the functions are progressively enhanced, achieving comprehensive optimization of efficiency, safety, quality and controllability in TBM tunnel drainage construction.

[0015] Compared with existing technologies, this invention not only ensures the stability of the drainage channel, avoiding the collapse or blockage of the orifice caused by surrounding rock deformation or seepage erosion in traditional bare boreholes, but also provides an effective seal through the tight fit between the expansion section and the borehole wall, preventing groundwater leakage along the casing perimeter and significantly improving the long-term reliability of the drainage borehole. A ball valve is installed at the outer end of the channel, upgrading the traditional drainage borehole from a "normally open passive" state to an "actively controlled" state. During construction, the opening of the ball valve can be adjusted according to the actual water inflow to control the drainage flow and prevent excessive drainage from causing ground subsidence due to water loss. Attached Figure Description

[0016] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the expansion anchor drainage device of the present invention;

[0018] Figure 2 This is a schematic diagram of the internal structure of the expansion anchor drainage device of the present invention;

[0019] Figure 3 This is a schematic diagram of part of the operation process of the present invention;

[0020] Figure 4 This is a schematic diagram of the drilling rig's operating state according to the present invention;

[0021] Figure 5 This is a schematic diagram of the final operating state of the expansion anchor drainage device of the present invention. Detailed Implementation

[0022] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example 1, as Figure 1As shown, an expansion anchoring drainage device for TBMs includes an anchoring drainage assembly. The assembly comprises an expansion sleeve 1 and a hollow screw rod 2 housed within the expansion sleeve 1. These two components work together to anchor and seal the initial support layer and shallow rock mass of the tunnel within a pre-drilled hole via mechanical expansion. The central through-hole 24 inside the hollow screw rod 2 serves as either a drill rod channel or a water flow channel. When the central through-hole 24 acts as a drill rod channel, the drill rod 5 drills into the rock mass through the central through-hole 24 until it penetrates to the aquifer, forming a drainage hole 7. After the drill rod 5 withdraws from the central through-hole 24, the central through-hole 24 becomes a water flow channel. When the central through-hole 24 is a water flow channel, a ball valve 3 is threadedly connected to the rear end of the hollow screw rod 2. The ball valve connected by the threaded end of the hollow screw gives the drainage device active control capability, enabling autonomous control of the drainage status: construction personnel can open, close, or adjust the opening of the ball valve in real time according to the seepage situation at the working face, the TBM advancing speed, and the water level in the chamber, achieving refined management of drainage when needed and stopping when needed, avoiding flooding of the chamber or equipment damage due to sudden water inrush; graded pressure reduction to protect the surrounding rock: for high-pressure and water-rich strata, graded pressure reduction can be achieved by gradually opening the ball valve, preventing sudden changes in rock stress, water inrush, mud inrush and other disasters caused by one-time pressure relief, and ensuring construction safety.

[0024] In the technical solution of this invention, by combining the expansion anchoring mechanism with the hollow channel, two key technical breakthroughs are achieved: First, the mechanical anchoring force of the expansion kit ensures a reliable connection between the device and the tunnel wall, solving the problem of exposed and unprotected conventional drainage holes and providing a stable interface for subsequent operations in the hollow channel; Second, the step-by-step construction method of "casing anchoring first, drill rod secondary drilling" ensures the stability and sealing of the borehole opening during drilling and allows the drill rod to accurately extend to the target aquifer. Furthermore, the introduction of an external ball valve transforms the traditional drainage hole from a "passively open" state to an "actively controllable" state. In TBM tunnel construction, this invention enables the standardization and controllability of drainage hole operations, significantly improving the construction safety of high-pressure, water-rich strata.

[0025] Example 2, as Figure 2As shown, an expansion anchoring drainage device for TBMs is further optimized based on Embodiment 1. In this embodiment, the expansion sleeve 1 includes, from front to back, an expansion section 11, a connecting section 12, and a flange 13, which are integrally formed. The outer wall of the expansion section 11 is provided with several expansion flaps 111; after expansion, they can tightly fit against the hole wall to achieve anchoring and sealing. A sealing sleeve 4 is fitted onto the outer wall of the connecting section 12. The sealing sleeve 4 is made of EPDM rubber, which expands upon contact with water, thus producing a good sealing effect after complete confinement. The expansion flaps are embedded in the slightly concave and convex surfaces of the rock wall, forming a multi-point interlocking structure. This prevents the expansion flaps from loosening or falling off under high-pressure water flow impact or drilling tool vibration, ensuring the structural stability of the drainage channel throughout the entire construction period. The front end of the expansion section forms a mechanical hard seal with the rock wall through metal expansion flaps, while the connecting section forms a soft seal through an elastic sealing sleeve. The combination of soft and hard seals effectively blocks the seepage path of aquifer water along the gaps in the borehole wall, ensuring that the water flow is only controlled and discharged through the central through hole.

[0026] In this preferred embodiment, the outer diameter of the hollow screw is slightly smaller than the inner diameter of the expansion sleeve. The hollow screw 2, from front to back, includes a tapered tail section 21, a smooth section 22, and a threaded section 23. The threaded section 23 extends out of the flange 13, and the nut 6, which is threadedly connected to the threaded section 23, drives the hollow screw 2 forward. The tapered tail section 21 expands the expansion section 11 of the expansion sleeve 1. The anchoring and drainage assembly formed by the expansion sleeve and the hollow screw utilizes the wedging fit between the tapered tail section and the expansion section to form a mechanical expansion anchor. When the nut is tightened, it drives the hollow screw to move axially forward, and the tapered tail section expands the expansion flaps, causing the outer wall of the expansion section to generate a radial clamping force against the borehole wall, forming a reliable mechanical anchor.

[0027] Example 3 presents an expansion anchoring drainage device for TBMs, further optimized from Examples 1 or 2. In this example, the central through-hole 24 can also serve as a grouting sealing channel or a water pressure monitoring channel. This design allows for flexible and adaptable post-treatment: the same channel can be converted into a grouting sealing channel after drainage, achieving "drainage-sealing" operations in the same hole, avoiding the additional workload of drilling separate grouting holes; simultaneously, it can be switched to a water pressure monitoring channel at any time, providing real-time data support for dynamically monitoring the evolution of aquifer water pressure, facilitating construction safety early warning. This invention solves the problems of insufficient anchoring force and easy loosening and detachment in traditional drainage hole structures through expansion mechanical anchoring; it solves the problems of complex multi-process conversion and easy channel blockage through the multi-functional reuse of the central through-hole; it solves the problems of hole wall leakage and sealing failure through the synergistic use of the sealing sleeve and expansion structure; and it solves the problems of uncontrollable drainage and inability to adjust as needed through external ball valve control. The overall solution represents a significant leap forward in the structural reliability, ease of construction, functional integration, and operational controllability of TBM drainage devices. It is particularly suitable for TBM tunnel construction environments characterized by high pressure, abundant water, limited space, and compact procedures, and has significant engineering practical value and promising prospects for widespread application.

[0028] Example 4: A construction method for an expansion anchor drainage device for TBMs based on Example 1, 2, or 3, as follows: Figure 3 , 4 As shown in Figure 5; the steps are as follows:

[0029] S1 Drilling the First-Stage Hole: On the surface of the initial support layer (sprayed concrete layer) of the TBM tunnel, a pre-drilled hole of a certain depth is drilled using the first drill bit; the diameter of the first drill bit is slightly larger than the outer diameter of the expansion sleeve. The diameter, depth, and orientation of the pre-drilled hole can be independently and precisely controlled, providing a geometric reference for the smooth insertion and expansion anchoring of the expansion sleeve, and avoiding uneven stress on the expansion sleeve or anchoring failure due to duct deviation.

[0030] S2 Mechanical Anchoring: The anchoring and drainage assembly is inserted into the pre-drilled hole, and a nut 6 is pre-installed on the hollow screw 2. By rotating the nut 6, the hollow screw 2 is pushed forward, causing it to expand the expansion sleeve 1 and tightly embed the expansion section 11 of the expansion sleeve 1 into the hole wall, thus achieving mechanical anchoring. At this time, a reliable frictional connection and seal are formed between the expansion sleeve and the hole wall, preventing groundwater leakage from the outer gap of the sleeve. Before the drill pipe enters the deep rock mass, the mechanical locking of the anchoring and drainage assembly to the surrounding rock is completed. During subsequent deep hole drilling, the hollow screw serves as a guide sleeve and support frame for the drill pipe, effectively suppressing drill pipe sway and vibration, improving drilling trajectory accuracy, and reducing the risk of drill pipe breakage. The nut is pre-fitted onto the exposed threaded section, allowing construction personnel to tighten it from the outside of the hole using a conventional wrench, eliminating the need to enter the narrow hole. This meets the ergonomic requirements of TBM in confined spaces, and the tightening torque is easy to control and detect.

[0031] S3 Drilling of Drainage Holes: Drill rod 5 is inserted into the central through hole 24 of hollow screw rod 2 and drilled into the rock mass until it penetrates to the aquifer, forming drainage hole 7. This step embodies the high degree of integration of casing wall protection, central guidance, and deep hole drilling; the hollow screw rod always acts as a temporary support casing for the borehole wall during drilling, effectively isolating the drill bit from direct contact with the borehole wall and preventing damage to the borehole wall from drilling fluid scouring and drill bit vibration, which is especially suitable for water-rich strata with developed fractures and broken rock masses; the central through hole provides precise axial guidance and constraint for the drill rod, making it less prone to deviation when the drill rod passes through uneven strata or inclined rock layers, ensuring that the drainage hole can accurately penetrate the target aquifer layer according to the designed trajectory; in this method, the drill rod is drilled through the internal channel of the hollow screw rod, and the drainage channel can be formed by directly withdrawing the drill rod after drilling is completed, without the need for secondary pipe insertion, completely eliminating the risk of borehole collapse and blockage caused by secondary pipe insertion.

[0032] S4 Ball Valve Installation: After drilling the drainage hole, withdraw the drill rod 5 from the central through hole 24, and then install the ball valve 3 on the threaded section 23 at the rear end of the hollow screw 2, forming a drainage channel with controllable opening. Installing the ball valve at the outer end of the channel upgrades the traditional drainage hole from a "normally open passive" state to an "actively controlled" state. During construction, the opening of the ball valve can be adjusted according to the actual water inflow to control the drainage flow and avoid excessive drainage causing ground subsidence. In this step, before installing the ball valve 3, remove the nut 6 to facilitate the smooth installation of the ball valve. In subsequent construction, adjust the ball valve opening as needed. Before pouring the secondary lining, close the ball valve for back grouting to prevent grout loss; during operation, when the water pressure is too high, open the ball valve to release the water pressure and prevent the lining from bearing excessive water pressure.

[0033] Steps S1 to S4 are not simply sequential; rather, they form a closed-loop technology of "pre-positioning—pre-anchoring—deep drilling—post-control." Precise pre-drilling for guidance solves the problems of difficult drainage hole location and duct deviation. The reversed process of anchoring before drilling addresses the issues of long anchoring curing times and unstable drilling processes inherent in traditional methods. Integrated drilling of the central through-hole solves the problems of easy hole collapse during secondary pipe installation and complex process transitions. The immediate use of the rear-end ball valve addresses the issues of uncontrollable drainage and inflexible subsequent handling. These four interconnected steps, with progressively enhanced functions, achieve comprehensive optimization of efficiency, safety, quality, and controllability in TBM tunnel drainage construction. It is particularly suitable for TBM excavation environments characterized by high pressure, abundant water, limited space, and tight schedules, demonstrating outstanding engineering practical value and broad application prospects.

[0034] In step S2, a sealing sleeve 4 is fitted onto the hollow screw 2 of the anchoring drainage component. The sealing sleeve 4 expands upon contact with water, providing a seal after mechanical anchoring and preventing groundwater leakage from the outer gap of the pipe sleeve. By using a water-swellable material for the sealing sleeve, it achieves physical compression sealing not only through the radial tension of the expansion sleeve after mechanical anchoring but also through volume expansion upon contact with groundwater, forming a secondary seal. The sealing performance adaptively enhances with water pressure, achieving a chemical amplification of the "pressure self-tightening" effect. The sealing contact stress of a traditional mechanical sealing sleeve depends only on the radial opening force of the expansion sleeve, which is a constant value. However, the water-swellable sealing sleeve absorbs water and its volume increases upon contact with groundwater, generating additional radial expansion stress. When the formation water pressure increases, the contact stress between the sealing sleeve and the borehole wall not only does not decrease but also increases synchronously due to the continuous water absorption and expansion of the material, forming a positive feedback effect of "the higher the water pressure, the tighter the seal." This characteristic is particularly crucial for high-pressure, water-rich formations, effectively addressing the problem of leakage failure of traditional sealing sleeves under high water pressure due to insufficient contact stress. Furthermore, the borehole walls of TBM tunnels often exhibit uneven microstructures due to rock fragmentation, drill bit vibration, or the development of fissures. Traditional rigid or low-elasticity sealing sleeves are difficult to completely conform to these microscopic defects, easily forming leakage channels. Water-swellable materials possess properties similar to "rheological filling," softening and expanding after absorbing water. They can actively penetrate and fill the micro-cracks, pits, and gaps between expansion lobes on the borehole wall surface, achieving a dual seal of macroscopic compression and microscopic sealing, significantly reducing the probability of leakage from external gaps.

[0035] In step S2, when the anchoring drainage component is inserted into the pre-drilled hole, a wedge-shaped pad 8 is placed between the surface of the initial support layer and the flange portion 13 of the expansion sleeve 1. The surface of the initial support layer in TBM tunnels (especially the shotcrete surface) is usually uneven, with local bumps, inclinations, or curvature variations. If the flange portion is directly attached to the uneven surface, it will cause an angle between the axis of the hollow screw and the axis of the pre-drilled hole. The wedge-shaped pad can compensate for the unevenness of the initial support layer surface by adjusting its wedge angle and thickness, making the end face of the flange portion tend to be perpendicular to the axis of the pre-drilled hole, ensuring that the hollow screw obtains accurate axial positioning. When the nut is tightened, the axial force is transmitted along the screw axis without eccentric load, and the expansion petals of the expansion sleeve are evenly spread, resulting in stable and controllable anchoring quality. For the arc-shaped initial support surfaces commonly found in TBM tunnels (such as the inner arc surface of the segment lining or the horseshoe-shaped cross-section shotcrete surface), it is difficult for the flat flange portion to fit the curved surface. Wedge-shaped pads can be prefabricated to the corresponding arc according to the curvature of the surface or flexible wedge-shaped pads can be used to form surface contact rather than line contact between the flange and the support surface, which can adapt to the installation requirements of various cross-section forms of TBM tunnels and improve the standardization and versatility of the device.

[0036] The water-swellable sealing sleeve, through a dual mechanism of "mechanical preloading + water expansion," solves the technical bottleneck of traditional sealing sleeves being prone to leakage and loosening under high water pressure, rough hole walls, and long-term service conditions, achieving adaptive enhancement of sealing performance and long-term durability. The wedge-shaped pad, through angle compensation, load distribution, and orifice sealing, solves the problems of installation misalignment, stress concentration, and orifice damage caused by unevenness of the initial support layer surface, achieving precise anchoring force transmission and protection of the initial support layer. Together with the expansion anchoring component, these two components further enhance the invention's sealing reliability, installation convenience, and field adaptability, making it more suitable for the actual engineering needs of water drainage construction in water-rich strata of TBM tunnels.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An expansion anchor drainage device for TBM, characterized in that: The device includes an anchoring and drainage assembly, which includes an expansion sleeve (1) and a hollow screw (2) disposed inside the expansion sleeve (1). The central through hole (24) inside the hollow screw (2) is a drill pipe channel or a water flow channel. When the central through hole (24) is a water flow channel, a ball valve (3) is threadedly connected to the rear end of the hollow screw (2).

2. The expansion anchor drainage device for TBM according to claim 1, characterized in that: The expansion sleeve (1) includes an expansion section (11), a connecting section (12) and a flange (13) from front to back. The outer wall of the expansion section (11) is provided with a plurality of expansion flaps (111); the outer wall of the connecting section (12) is provided with a sealing sleeve (4).

3. The expansion anchor drainage device for TBM according to claim 2, characterized in that: The hollow screw (2) consists of a tapered tail section (21), a smooth section (22), and a threaded section (23) from front to back. The threaded section (23) extends out of the flange (13) and is driven forward by the nut (6) that is threaded to the threaded section (23). The tapered tail section (21) expands the expansion section (11) of the expansion sleeve (1).

4. The expansion anchor drainage device for TBM according to any one of claims 1 to 3, characterized in that: When the central through hole (24) serves as the drill pipe channel, the drill pipe (5) drills into the rock mass through the central through hole (24) until it penetrates to the aquifer to form a drainage hole (7).

5. The expansion anchor drainage device for TBM according to claim 4, characterized in that: After the drill rod (5) is withdrawn from the central through hole (24), the central through hole (24) serves as a water flow channel.

6. The expansion anchor drainage device for TBM according to claim 1 or 5, characterized in that: The central through hole (24) can also be used as a grouting and sealing channel or a water pressure monitoring channel.

7. A construction method for an expansion anchor drainage device for TBMs according to any one of claims 1 to 6, characterized in that: The steps are as follows: S1 Drilling the first-stage hole: On the surface of the initial support layer of the TBM tunnel, a pre-drilled hole of a certain depth is drilled using the first drill bit; S2 Mechanical Anchoring: Insert the anchoring drainage assembly into the pre-drilled hole and pre-install a nut (6) on the hollow screw (2). By rotating the nut (6), the hollow screw (2) is rotated forward to open the expansion sleeve (1) and the expansion section (11) of the expansion sleeve (1) is tightly embedded in the hole wall to achieve mechanical anchoring. S3 Drilling drainage holes: Insert the drill rod (5) into the central through hole (24) of the hollow screw rod (2) and drill into the rock mass until it penetrates to the aquifer to form a drainage hole (7). S4 Install ball valve: After the drain hole is drilled, the drill rod (5) is pulled out from the central through hole (24), and then the ball valve (3) is installed on the threaded section (23) at the rear end of the hollow screw (2) to form a drain channel with controllable opening.

8. The construction method according to claim 7, characterized in that: In step S2, a sealing sleeve (4) is fitted on the hollow screw (2) of the anchoring drainage component. The sealing sleeve (4) expands when it comes into contact with water and plays a sealing role after mechanical anchoring to prevent groundwater from leaking out of the outer gap of the pipe sleeve.

9. The construction method according to claim 8, characterized in that: In step S2, when the anchoring drainage assembly is inserted into the pre-drilled hole, a wedge-shaped pad (8) is placed between the surface of the initial support layer and the flange (13) of the expansion sleeve (1).

10. The construction method according to claim 8 or 9, characterized in that: In step S4, before installing the ball valve (3), remove the nut (6); in subsequent construction, adjust the opening of the ball valve as needed, close the ball valve before the secondary lining is poured to perform back grouting to prevent grout loss; during operation, when the water pressure is too high, open the ball valve to release the water pressure to avoid the lining being subjected to excessive water pressure.

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