An irregular orifice plugging material based on polyurethane-silicate for use in plugging a formation borehole, a plugging device and a method of construction

Abstract

This invention discloses a grout-stopping material, grout-stopping device, and construction method for irregular borehole openings based on polyurethane-water glass, suitable for sealing formation boreholes, belonging to the field of formation borehole sealing and grout-stopping technology. The grout-stopping material consists of components A and B, and the gelation time after mixing can be controlled within 16~60 s, with the solidified body achieving a compressive strength of 5~10 MPa after 60 s. The grout-stopping device includes a solid or hollow rod, a grouting pipe, a grout-stopping material barrier plate at the borehole opening, an vent pipe, a grout-stopping material hose, an annular gasket, a tray, and a lock. During construction, the mixed grout is injected into the gap between the rod and the irregular borehole wall through the grout-stopping material hose. The grout self-fills and rapidly solidifies to form a self-adhesive grout-stopping plug, providing both reliable sealing and auxiliary anchoring functions. This invention can effectively adapt to various working conditions such as pipe roof borehole openings and upward, downward, and near-horizontal anchor bolts, solving the problems of high dependence on borehole wall regularity and unreliable sealing in existing formation borehole sealing and grout-stopping technologies.

Description

Technical Field

[0001] This invention belongs to the field of formation borehole sealing and grouting technology, and relates to the design of borehole grouting material formulation, borehole sealing device design, and integrated injection and drainage construction process. Specifically, it is a grouting material, grouting device, and construction method for irregular boreholes based on polyurethane-water glass suitable for sealing formation boreholes. Background Technology

[0002] In geotechnical engineering, tunnel and underground engineering, resource exploration, slope protection, and foundation pit engineering, drilling is a fundamental technical means for implementing grouting reinforcement, fracture sealing, exploration sampling, curtain seepage prevention, and borehole monitoring. During construction and service, drilling in strata typically requires the formation of reliable sealing and grout stopping at the borehole opening to prevent grout or sealing media from escaping along the opening and avoiding problems such as difficulty in establishing pressure inside the borehole, limited effective diffusion radius, or leakage channels around the borehole wall. Especially in the openings and sections of tunnels in complex strata such as shallow burial, weak and fractured, high ground stress, or fault zones, the borehole opening section is often accompanied by phenomena such as borehole wall collapse and irregular diameter expansion, making it difficult to continuously adhere the sealing interface at the borehole opening. This, in turn, makes it difficult for the grout injected into the borehole cavity to fill completely and densely and to fully penetrate into the very near-hole wall, directly affecting the effect of surrounding rock reinforcement, the reliability of sealing and grout stopping, and the safety of durable service.

[0003] Existing borehole sealing and grout-stopping technologies mainly include mechanical packers, elasto-plastic grout-stopping plugs, and chemical / mineral-based material sealing methods. Mechanical packers achieve borehole wall sealing through the radial expansion of rubber sleeves or metal slips, but they require extremely high borehole diameter regularity; otherwise, stress concentration can easily occur, leading to seal failure. Elastic-plastic grout-stopping plugs rely on the elastic deformation of the material itself to fill the gaps in the borehole wall. Although they have a certain deformation adaptability, their sealing interface is prone to forming leakage channels, making it difficult to meet the sealing requirements of medium- and high-pressure operations. In terms of sealing materials, cement-based grouts are widely used due to their good pumpability and economy, but they have long setting times and are accompanied by significant volume shrinkage during the curing process, which easily creates microcrack channels at the pore wall interface. Inorganic chemical grouts usually have the characteristics of adjustable gel time and low initial viscosity, but their erosion and shear resistance of the cured body is limited. Organic polymer sealing materials usually have good interfacial adhesion and a certain degree of flexibility, but they have problems such as exothermic curing, rapid viscosity increase leading to a narrow construction window, and sensitivity to mixing ratio. Although some foamed materials can fill large pores, it is difficult to balance their closed-cell structure with overall strength.

[0004] Furthermore, in engineering practice, the drilling and grouting process under various working conditions is prone to the following problems: During pipe roof grouting, the grouting pressure cannot be increased and maintained due to inadequate grout sealing, resulting in insufficient grout diffusion and non-compactness. Even if segmented or backward grouting is adopted, the effect is still unsatisfactory. During upward anchor bolt construction, the anchoring of disposable drill bit ends attached to mechanical anchor heads and self-advancing anchor bolts often encounters problems such as installation difficulties or detachment during installation or grouting, making it difficult to implement medium- and high-pressure grouting. During near-horizontal anchor bolt construction, the grout in the rear section of the anchor hole is often not fully filled due to inadequate sealing of the borehole opening, or gravity leakage after grouting. During downward anchor bolt construction, the borehole opening section often becomes self-blocked by grout due to inadequate sealing, and medium- and high-pressure grouting cannot be applied, resulting in sections of the anchor bolt without grout.

[0005] To address the aforementioned challenges, existing technologies have explored various approaches, but significant limitations remain, such as:

[0006] Chinese patent CN206554832U discloses an in-hole grouting component and a grouting anchor cable and anchor rod using the component. It arranges a metal tube, a blocking component and a sealing material layer on the outside of the cable / rod body to seal the gap between the cable / rod body and the borehole wall. However, its sealing method is limited by the matching relationship between the outer diameter of the grouting plug and the borehole diameter, and its adaptability to working conditions such as the through-hole cracks, irregular diameter expansion and surface defects at the borehole opening is insufficient.

[0007] CN115614096B discloses a sealing method using a grout-stopping tape insertion device for borehole sealing. The sealing target focuses on deep isolation within the borehole and grout crosstalk between adjacent boreholes. It is difficult to form a sealing interface with shear resistance, erosion resistance and high pressure bearing capacity for the stepped diameter expansion and irregular borehole walls at the borehole opening. It is also difficult to solidify with the borehole sealing material to form an integrated and sustainable borehole sealing structure.

[0008] CN205895289U discloses a grouting anchor cable with double-layer grout sealing and spiral stirring functions. This technology uses rubber plug compression to achieve sealing, has a simple structure, and is currently a widely used grout sealing method. However, its sealing effect is heavily dependent on the smoothness and regularity of the borehole wall, and is ineffective for sealing irregularly shaped borehole sections.

[0009] In addition, CN110593808B discloses a grout sealing device and a method for sealing grouting anchors. This method utilizes the foaming and expansion properties of polyurethane to fill irregular pores, thus improving its adaptability. However, the foamed material has low strength and a loose structure after curing, resulting in poor compressive and impermeability. It is only suitable for sealing irregular pore sections under low-pressure grouting conditions and cannot withstand the working pressure of high-pressure grouting. Furthermore, it does not have an auxiliary anchoring function.

[0010] In summary, existing formation borehole plugging and grouting technologies still have significant shortcomings in terms of adaptability to irregular borehole openings, sealing reliability, interfacial bonding strength, and functional integration. They are insufficient to meet the engineering requirements for systematic, reliable, and high-strength plugging under complex formation conditions. Therefore, developing highly adaptable grouting materials for formation borehole plugging, along with matching plugging devices and construction methods that can reliably seal the borehole surface, to improve the feasibility and stability of formation borehole plugging and grouting, is a pressing technical problem that needs to be solved in this field and has significant engineering implications. Summary of the Invention

[0011] (a) Purpose of the invention

[0012] To overcome the aforementioned defects and shortcomings of existing formation borehole sealing and grouting technologies, this invention aims to provide a grouting material, grouting device, and construction method for irregular boreholes based on polyurethane-water glass, suitable for sealing formation boreholes. This addresses common technical bottlenecks such as difficulty in sealing irregular borehole walls, difficulty in maintaining grouting pressure, limited functionality of common grouting materials, and poor adaptability to various working conditions. At the material level, the two-component, fast-curing grout designed in this invention features controllable gelation time and medium-to-high strength within minutes. It can actively fill gaps in adjacent borehole walls and adhere to irregular borehole walls, forming a self-adhesive seal with micro-expansion and high adhesion properties, providing both reliable grouting and auxiliary anchoring functions. At the device level, this invention achieves localized filling of the grouting material, effective venting, and fullness criterion control through barrier plate confinement, multi-port trays, and integrated injection and drainage piping, supporting various construction inclination angles. This invention is adaptable to drilling at different inclination angles, such as upward, near-horizontal, and downward, forming a systematic, reliable, and easy-to-operate high-strength bonding and sealing solution for borehole openings. By improving the fullness of grouting, it provides a basic guarantee for the quality of borehole treatment and reduces the reliance on mechanical anchoring at the ends, thus effectively adapting to various complex engineering scenarios.

[0013] (II) Technical Solution

[0014] To achieve the objective of this invention and solve its technical problems, the present invention adopts the following technical solution:

[0015] The first objective of this invention is to provide a grout-stopping material for irregular borehole openings based on polyurethane-water glass, suitable for sealing formation boreholes, comprising at least component A and component B, wherein:

[0016] The raw materials for preparing component A include, by weight, at least: 80-100 parts of polymethylene polyphenyl polyisocyanate, 10-20 parts of polyether polyol, and 5-10 parts of plasticizer;

[0017] The raw materials for preparing component B include, by weight, at least: 30-50 parts of water glass and 1-2 parts of tertiary amine catalyst, wherein the water glass is selected from sodium water glass and / or potassium water glass, and its modulus is 2.2-3.0;

[0018] When used, components A and B are mixed in a volume ratio to form a mixed slurry. The volume ratio should be set to ensure that the gelation time of the mixed slurry is controlled between 16 and 60 seconds, the initial setting time is controlled to be no more than 60 seconds, and after curing, a composite solidified body with a double cross-linked structure of polyurethane polymer network and silicate gel is formed, and the compressive strength of the solidified body at 60 seconds is not less than 5 MPa.

[0019] The second objective of this invention is to provide a grout-stopping device for sealing irregular borehole openings in formation drilling. Employing the aforementioned grout-stopping material of this invention, the device includes at least a rod body, a borehole sealing assembly, a grout-stopping material confinement assembly, and a grout-stopping material injection assembly, wherein:

[0020] The rod is a solid or hollow rod, arranged along the borehole axis and passing through the borehole area. Its outer end forms a connecting end for assembly and locking, and its inner end extends into the borehole to form a channel support reference.

[0021] The orifice sealing assembly includes an annular pad, a tray, and a lock. The annular pad is attached to the outer rock surface of the borehole orifice. The tray is coaxially arranged and has a central through hole for the rod body to pass through. The lock is detachably connected to the outer end of the rod body and applies axial pressure to the tray after the grouting material has cured, so that the annular pad forms an orifice surface sealing interface between the rock surface and the tray.

[0022] The grout-stopping material confinement assembly includes at least a grout-stopping material barrier plate sleeved on the outer periphery of the rod body and located on the side of the tray facing the hole, and a positioning limiter. The barrier plate is sleeved on the rod body and fixed to the rod body by the positioning limiter, so that the barrier plate, tray, borehole wall, and outer wall of the rod body together enclose the grout-stopping material filling cavity at the orifice and limit the axial filling range of the grout-stopping material in the irregular section of the orifice.

[0023] The grout-stopping material injection assembly includes at least a grout-stopping material injection hose that passes through the tray and extends into the grout-stopping material filling cavity at the orifice. It is used to inject the grout-stopping material mixture into the filling cavity and solidify it to form an orifice grout-stopping seal, and cooperate with the orifice sealing assembly to achieve pressure-bearing sealing of the orifice.

[0024] The third objective of this invention is to provide a construction method based on the above-mentioned grout-stopping device for sealing irregular borehole openings in formation drilling, comprising at least the following steps:

[0025] SS1. Construction preparation: Drill holes along the design direction to the preset depth. After drilling, clean the rock powder and water inside the hole. Select the appropriate grouting device according to the drilling angle, hole diameter and rod type. Prepare grouting materials A and B, grouting cement slurry and corresponding grouting equipment.

[0026] SS2. Installation of the grout-stopping device: Insert the rod along the borehole axis to the designed position, with its outer end extending out of the borehole to form a connection end and its inner end extending into the borehole to form a support reference; place the grout-stopping material barrier plate on the rod and use the limiting device to limit and fix it at a preset depth position from the borehole, ensuring that its outer edge is in contact with the borehole wall; install the annular pad, tray, and lock in sequence at the borehole, and connect the grouting pipe, vent pipe, and grout-stopping material hose, so that the annular pad forms a sealing interface on the borehole surface between the rock surface and the tray, and together with the barrier plate, the borehole wall, and the outer wall of the rod, forms a grout-stopping material filling cavity at the borehole;

[0027] SS3. Preparation and injection of grout sealing material at the orifice: Mix component A and component B of the grout sealing material thoroughly in proportion to form a polyurethane-water glass grout sealing material mixture; inject the mixture into the orifice grout sealing material filling cavity quickly through the grout sealing material injection hose, so that the mixture fully fills the annular gap in the irregular section of the orifice and adheres to the orifice wall;

[0028] SS4. Curing, Locking and Sealing: During the injection process, the grouting material discharges the gas in the filling cavity through the gap between the annular pad and the rock surface outside the borehole. After the mixed grout solidifies in situ in the irregular section of the borehole to form a solidified borehole grouting plug, which is coupled with the borehole wall, the locking device is tightened to apply axial pressure to the tray, so that the annular pad and the rock surface form a sealing interface on the borehole surface, and the borehole grouting plug and the sealing interface work together to form a pressure-bearing sealing structure at the borehole.

[0029] SS5. Grouting Operation: When the grout-stopping sealant in the irregular section of the borehole reaches the design strength and can withstand the grouting pressure (medium and low pressure grouting can be done in 1 minute, high pressure grouting requires 3 minutes), grouting is carried out into the borehole through the grouting pipe or hollow rod. The gas in the borehole is discharged through the vent pipe, which also serves as an observation port for judging the fullness of grouting. The grouting channel is closed and grouting is completed when the vent pipe is full of grout, thus completing the sealing and reinforcement of the entire borehole section.

[0030] (III) Technical Effects

[0031] Compared with the prior art, the grout-stopping material, grout-stopping device, and construction method of the present invention, which are applicable to sealing formation boreholes and are based on polyurethane-water glass for irregular borehole openings, have the following beneficial technical effects:

[0032] (1) Commonly used elasto-plastic material physical adhesion grout stoppers rely on their own deformation to fill gaps, which requires high regularity of the borehole wall and is prone to leakage due to borehole diameter expansion and roughness of the borehole wall. The grout stopper provided by the present invention is in a fluid state when injected, which can autonomously fill various irregular gaps and micro-cracks between the borehole wall and the rod body, and further enhance the interfacial bonding strength through the micro-expansion effect during the curing process, thereby fundamentally solving the grout leakage problem caused by irregular borehole wall and improving the reliability and stability of formation borehole sealing and grout stopper.

[0033] (2) The grout-stopping material system of the present invention is optimized and can complete initial setting within 30 seconds after mixing, and the strength can reach 5~10 MPa within 1 minute, which is the strength required to bear the grouting pressure. This feature greatly shortens the process interval, prevents the grouting rod from falling back, and can eliminate the mechanical anchor head to enable the grouting operation to be connected quickly. This not only improves the construction efficiency, but also reduces the risk of the sealing body being damaged by external force or water flow before solidification, and ensures the continuity of the project.

[0034] (3) Unlike traditional grout stoppers that only have a sealing function, the grout stopper material of this invention can form a strong chemical and physical bond with the rock mass and the surface of the rod after curing. Its micro-expansion characteristics can also generate pre-tightening force at the contact interface. This makes the sealing structure not only achieve sealing, but also become an auxiliary anchoring unit in the support system, enhancing the integrity of the anchor rod and the surrounding rock, and improving the long-term stability and bearing capacity of the support system.

[0035] (4) Through the integrated and coordinated design of material properties and device structure, this invention can systematically adapt to various complex construction conditions. In the case of grouting at the pipe roof orifice, it can achieve reliable sealing of the orifice, effectively maintain grouting pressure, and promote full diffusion of grout, thereby improving the overall support effect of the pipe roof. In the case of upward anchor bolt construction, it can replace the traditional easily detachable cement cartridges or mechanical anchor heads, forming a sealing body with both sealing and auxiliary anchoring functions, ensuring the smooth implementation of grouting. In the case of downward anchor bolt construction, it can form a stable self-sealing structure at the orifice, preventing grout backflow and ensuring grout fullness and anchoring quality. In the case of near-horizontal anchor bolt construction, it can achieve tight sealing of the orifice, ensuring dense grout filling throughout the hole, optimizing the stress of the anchoring system, and improving its integrity and durability. This invention comprehensively covers the key grouting conditions in typical projects and has broad applicability and significant technical integration advantages. Attached Figure Description

[0036] Figure 1 A schematic diagram of a grout-stopping device for irregular borehole openings used to seal formations.

[0037] Figure 2The diagram shows the cross-sectional structure and construction stages of the pipe roof, where: (a) is the cross-sectional structure and construction stage before grouting, (b) is the cross-sectional structure and construction stage during the grouting process, and (c) is the cross-sectional structure and construction stage after grouting.

[0038] Figure 3 The diagram shows the cross-sectional structure and construction stages of an upward solid anchor bolt, where: (a) is the cross-sectional structure and construction stage before grouting of the borehole, (b) is the cross-sectional structure and construction stage during the grouting process of the borehole, and (c) is the cross-sectional structure and construction stage after the grouting of the borehole.

[0039] Figure 4 The diagram shows the cross-sectional structure and construction stages of the upward hollow anchor bolt, where: (a) is the cross-sectional structure and construction stage before grouting of the borehole, (b) is the cross-sectional structure and construction stage during the grouting process of the borehole, and (c) is the cross-sectional structure and construction stage after the grouting of the borehole.

[0040] Figure 5 The diagram shows the cross-sectional structure and construction stages of a solid anchor bolt with an upward sloping borehole, where: (a) is the cross-sectional structure and construction stage before grouting of the inclined borehole, (b) is the cross-sectional structure and construction stage during the grouting process of the inclined borehole, and (c) is the cross-sectional structure and construction stage after the grouting of the inclined borehole.

[0041] Figure 6 The diagram shows the cross-sectional structure and construction stages of the inclined hollow anchor bolt, where: (a) is the cross-sectional structure and construction stage before grouting of the inclined hole, (b) is the cross-sectional structure and construction stage during the grouting process of the inclined hole, and (c) is the cross-sectional structure and construction stage after the grouting of the inclined hole.

[0042] Figure 7 The diagram shows the cross-sectional structure and construction stages of a near-horizontal solid anchor bolt, where: (a) is the cross-sectional structure and construction stage before horizontal hole grouting, (b) is the cross-sectional structure and construction stage during horizontal hole grouting, and (c) is the cross-sectional structure and construction stage after horizontal hole grouting.

[0043] Figure 8 The diagram shows the cross-sectional structure and construction stages of a near-horizontal hollow anchor bolt, where: (a) is the cross-sectional structure and construction stage before horizontal hole grouting, (b) is the cross-sectional structure and construction stage during horizontal hole grouting, and (c) is the cross-sectional structure and construction stage after horizontal hole grouting.

[0044] Figure 9 The diagram shows the cross-sectional structure and construction stages of a downward solid anchor bolt, where: (a) is the cross-sectional structure and construction stage before grouting in the borehole, (b) is the cross-sectional structure and construction stage during the grouting process in the borehole, and (c) is the cross-sectional structure and construction stage after the grouting in the borehole.

[0045] Figure 10The diagram shows the cross-sectional structure and construction stages of a downward hollow anchor bolt, where: (a) is the cross-sectional structure and construction stage before grouting in the borehole, (b) is the cross-sectional structure and construction stage during the grouting process in the borehole, and (c) is the cross-sectional structure and construction stage after the grouting in the borehole.

[0046] Figure 11 A construction flowchart for using an irregular borehole sealing device for sealing formations.

[0047] Explanation of reference numerals in the attached figures:

[0048] 1-Drill hole wall; 2-Annular gap of anchor bolt hole to be grouted; 3-Solid or hollow rod body; 4-Exhaust pipe; 5-Groove sealing material barrier plate at the borehole opening; 6-Groove sealing material solidified body at the borehole opening; 7-Groove pipe; 8-Groove sealing material hose at the borehole opening; 9-Annular pad; 10-Tray; 11-Lock; 12-Hollow anchor bolt cap; 13-Limiting component (limiting pin). Detailed Implementation

[0049] This invention aims to provide a grout-stopping material, device, and construction method for irregular borehole openings based on polyurethane-water glass, suitable for sealing formation boreholes. To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments will be described in more detail below with reference to the accompanying drawings. The described embodiments are some, but not all, embodiments of this invention, and are exemplary, intended to explain the invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0050] Example 1: Grout-stopping material

[0051] As a specific example, the polyurethane-water glass-based grouting material for sealing irregular borehole openings in formations provided by this invention is used for sealing irregular sections of borehole openings in formations. It solidifies in situ during grouting operations to form a pressure-bearing seal capable of withstanding grouting pressure. This grouting material employs a two-component reactive system, mainly comprising component A and component B, wherein:

[0052] The raw materials for preparing component A include, by weight, at least 80-100 parts of polymethylene polyphenyl polyisocyanate, 10-20 parts of polyether polyol, and 5-10 parts of plasticizer. Polyisocyanate serves as the main reactant, providing a rapid crosslinking framework; polyether polyol is used to construct a flexible polyurethane network to improve interfacial adhesion and shear resistance; and plasticizer is used to regulate the brittleness of the cured body and improve the bonding stability of irregular pore wall interfaces.

[0053] The raw materials for component B, by weight, include at least 30-50 parts of water glass and 1-2 parts of a tertiary amine catalyst, wherein the water glass is selected from sodium water glass and / or potassium water glass, and its modulus is 2.2-3.0. The water glass provides a silicon source and an alkaline environment for the formation of the silicate gel structure, and the tertiary amine catalyst is used to regulate the reaction induction period and promote early gel formation, enabling the material to complete the continuous transformation from injection to gelation to pressure bearing within a short time window at the orifice.

[0054] When using, components A and B are mixed in a volume ratio to form a mixed slurry. The volume ratio should be set to ensure that the gelation time of the mixed slurry is controlled between 16 and 60 seconds, and the initial setting time is controlled to be no more than 60 seconds. After curing, a composite solidified body with a double cross-linked structure of polyurethane polymer network and silicate gel is formed, and the compressive strength of the solidified body at 60 seconds is not less than 5 MPa, thereby meeting the requirements for rapid sealing and medium-to-low pressure sealing under irregular gap conditions of the orifice.

[0055] Furthermore, the raw materials for preparing component A also include 0.05-0.50 parts by weight of organotin catalyst and 0.20-2.00 parts by weight of siloxane surfactant. When mixed, the organotin catalyst forms a composite catalytic system with the tertiary amine catalyst in component B, used to finely control the reaction rate between isocyanate and hydroxyl groups and improve early gel strength. The siloxane surfactant is used to reduce interfacial tension and adjust the rheological properties of the mixed slurry, enabling the slurry to have stable spreading, wetting, and filling capabilities in irregular interfaces such as orifice collapse and stepped gaps, reducing pore defects caused by localized gas entrainment.

[0056] In addition, the raw materials for preparing component B also include 3-8 parts by weight of crosslinking accelerator and 1-3 parts by weight of viscosity modifier. The crosslinking accelerator is selected from silica sol, phosphate and / or disodium hydrogen phosphate with a particle size of 5-15 nanometers. It is used to regulate the silicate gel formation rate involving water glass and promote the early crosslinking and forming of the composite solid by providing active siloxane groups or adjusting the pH value to 9-11, so that the initial setting time is stabilized at 45-60 s. The viscosity modifier is selected from polyethylene glycol and / or glycerol with a molecular weight of 400-600. It controls the initial viscosity of component B at 200-500 mPa·s. After mixing with component A, the initial viscosity of the mixed slurry before injection is controlled at 500-2000 mPa·s to meet the pumpability and filling construction requirements under the condition of irregular gaps at the orifice, and ensure that it can be smoothly transported and filled to the depth of the orifice under an injection pressure of 0.2-0.5 MPa.

[0057] To verify the comprehensive sealing performance of the grout-stopping material in this embodiment, the grout-stopping material (denoted as S1) was compared with three common orifice sealing materials, including: cement-based grout (denoted as C1), water glass-based inorganic grout (denoted as C2), and single polyurethane foam sealing material (denoted as C3). Under the same orifice irregular gap model and the same injection conditions, the rheological properties, setting characteristics, early strength, interfacial adhesion, and pressure-bearing sealing stability of the mixed grout were tested. The test results are shown in Table 1 below.

[0058] Table 1 Comparison of performance test results of different grouting materials

[0059]

[0060] Note: "—" indicates that the material has been severely damaged under this pressure condition and cannot be effectively tested.

[0061] As can be seen from the test data in Table 1, the polyurethane-water glass composite grouting material (S1) of this embodiment is significantly superior to the other three comparative materials in all performance indicators. Specifically: (1) In terms of rheological properties, the initial viscosity of S1 is 625 mPa·s, which is at a moderate level, ensuring good pumpability and effectively filling the irregular gaps at the orifice without excessive loss. (2) In terms of setting and forming characteristics, the gelation time of S1 is 28 seconds. This setting speed avoids insufficient filling caused by excessively fast setting and ensures that an effective grouting barrier is formed in time at the depth of the orifice. (3) In terms of early strength, the compressive strength of S1 reaches 5.2 MPa at 60 seconds and 8.6 MPa at 3 minutes, indicating that the double cross-linked structure can quickly build a load-bearing skeleton and meet the requirements of rapid grouting operation. (4) Regarding interfacial bonding performance, the pull-out bond strength of S1 on the rock surface is 2.8 MPa, proving that the synergistic effect of polyurethane polymer segments and silicate gel effectively enhances the interfacial bonding ability between the grout stop and the rock wall. (5) Regarding pressure-bearing and sealing stability, no leakage (≤1 mL) was observed in S1 under a pressure of 0.5 MPa for 10 minutes; under a high-pressure condition of 3.0 MPa for 30 minutes, S1 still maintained a complete seal without leakage, indicating that S1 has excellent pressure-bearing and sealing capabilities and structural stability. Overall, the comparative test data show that the grout stop material in this embodiment is significantly superior to traditional single-component materials in key indicators such as rheological properties, setting rate, early strength, interfacial bonding, and pressure-bearing sealing.

[0062] It should be noted that the grouting material in this embodiment achieves rapid strength building through a dual cross-linking path of polyurethane network molding and silicate gel consolidation. Furthermore, with the assistance of a composite catalytic system and rheology-regulating components, the grout retains pumpability and adaptive spreading capabilities within a short construction window. It can actively fill irregular gaps formed by borehole collapse and maintain continuous interface adhesion, thereby forming a sealing structure at the borehole opening that combines adhesion, pressure bearing, and impermeability. In this embodiment, the ratio of component A to component B, the dosage range of each component raw material, and the curing time parameters can all be adaptively adjusted according to the degree of borehole irregularity, surrounding rock conditions, and grouting pressure level in actual engineering projects. When the orifice is severely broken or the grouting pressure is high, the amount of polymethylene polyphenyl polyisocyanate in component A can be appropriately increased to 90-100 parts, and the mass ratio of component A to component B can be adjusted to 2:1-1:1 to improve the rigidity and pressure bearing capacity of the cured body. When the orifice is relatively regular or the grouting pressure is medium to low, the amount of component B can be appropriately increased to achieve a mass ratio of 1.5:1-1:1 to reduce material costs.

[0063] Example 2: Grout Stopping Device

[0064] Based on Example 1, Example 2 provides a grout-stopping device for sealing irregular boreholes in formation. This device utilizes the aforementioned grout-stopping material for sealing irregular boreholes in formation, based on polyurethane-water glass. The following describes the details... Figure 1 The structural composition, assembly relationship, and functional implementation of the irregular orifice grouting device for sealing formation boreholes are described in detail.

[0065] like Figure 1 As shown, the grout-stopping device mainly includes a solid or hollow rod body 3, an orifice sealing assembly, a grout-stopping material confinement assembly, and a grout-stopping material injection assembly. The orifice sealing assembly includes an annular gasket 9, a tray 10, and a lock 11; the grout-stopping material confinement assembly includes an orifice grout-stopping material barrier plate 5 and a limiting member 13; and the grout-stopping material injection assembly mainly includes a grout-stopping material hose 8. Furthermore, when grouting is required inside the orifice, the grout-stopping device is further equipped with a grouting assembly, mainly including a grouting pipe 7 and an vent pipe 4. Wherein:

[0066] The rod 3 is a solid or hollow rod, arranged along the borehole axis and penetrating the borehole opening area. Its outer end forms a connecting end for assembly and locking, and its inner end extends into the borehole to form a channel support reference. The rod 3 can be selected as a pipe roof, solid anchor rod, or hollow anchor rod according to engineering needs, and different types of rod 3 have the same borehole positioning and sealing assembly foundation in this embodiment. When rod body 3 is a pipe roof, the pipe roof is made of Q345B seamless steel pipe with an outer diameter of Φ89mm and a wall thickness of 6mm. When rod body 3 is a solid anchor rod, the solid anchor rod is made of HRB400 grade left-hand threaded steel without longitudinal reinforcement with a diameter of Φ22mm. When rod body 3 is a hollow anchor rod, the hollow anchor rod is made of Q345B seamless steel pipe with an outer diameter of Φ25mm and a wall thickness of 3mm. Its inner cavity can also serve as a channel for grouting in the hole after the grout sealing body at the borehole has cured. At the same time, a hollow anchor rod cap 12 can be installed at the outer end of the hollow anchor rod. A PVC plug can be used to seal the tail of rod body 3.

[0067] In this embodiment of the invention, the borehole sealing assembly includes an annular pad 9, a tray 10, and a lock 11. The annular pad 9 is attached to the outer rock surface of the borehole opening. The tray 10 is coaxially arranged and has a central through hole through which the rod 3 passes. The lock 11 is detachably connected to the outer end of the rod 3 and applies axial clamping force to the tray 10 after the grouting material has cured, so that the annular pad 9 forms a borehole surface sealing interface between the rock surface and the tray 10. Wherein:

[0068] The annular gasket 9 is a highly elastic gasket made of rubber or polymer materials, with a thickness of about 5mm. It is placed between the rock surface of the borehole and the tray 10. During installation, it is tightly attached to the rock surface of the borehole, playing a preliminary sealing and stress buffering role, thereby improving the continuity, fit and pressure resistance of the sealing interface of the borehole surface.

[0069] The pallet 10 is a metal plate component, which is cut from Q235 steel plate with a thickness of about 8mm. It has a central hole for the rod 3 to pass through, and the diameter of the central hole matches that of the rod 3, so as to achieve coaxial positioning and unified assembly datum between the rod 3 and the pallet 10. As a preferred option, to adapt to different rod forms and achieve coordination between orifice grout sealing and in-hole grouting channel, the pipe through-hole arrangement of the tray 10 is set as follows: three or four pipe through-holes are evenly distributed around the central hole. When the rod 3 is a solid anchor rod or pipe roof, the number of pipe through-holes is four, evenly distributed around the circumference. Two symmetrical holes are connected to the grout sealing material hose 8 at the orifice, and the other two symmetrical holes are connected to the grouting pipe 7 and the vent pipe 4, respectively. When the rod 3 is a hollow anchor rod or hollow pipe roof, the number of pipe through-holes is three, evenly distributed around the circumference. Two holes are connected to the grout sealing material hose 8 at the orifice, and the other hole is connected to the vent pipe 4. In this case, the inner cavity of the rod 3 and the grouting pipe 7 are combined into the same channel. After the orifice grout sealing body is cured, the rod 3 also serves as an in-hole grouting pipe.

[0070] Lock 11 is a high-strength nut and washer that matches the thread of the rod body 3. It is used to tighten the anchor tray 10, fix the entire device, and change the sealing interface of the orifice from a close-fitting seal to a controlled axial pre-tightening seal, thereby improving the reliability of the orifice pressure-bearing grout stop.

[0071] In this embodiment of the invention, the grout-stopping material confinement assembly includes at least a grout-stopping material barrier plate 5 sleeved on the outer periphery of the rod 3 and located on the side of the tray 10 facing the hole, and a positioning limiting member 13. The barrier plate 5 is sleeved on the rod 3 and fixed to the rod 3 by the limiting member 13, so that the barrier plate 5, the tray 10, the borehole wall 1, and the outer wall of the rod 3 together enclose the grout-stopping material filling cavity at the borehole opening, and limit the axial filling range of the grout-stopping material in the irregular section of the borehole opening. Specifically:

[0072] The baffle plate 5, which is the grout-stopping material at the orifice, is preferably an annular disc made of ABS engineering plastic. Its outer diameter is adjusted according to the size and shape of the borehole, and its inner diameter is consistent with the outer diameter of the rod body 3. Its thickness is about 5 mm. The outer edge of the annular disc is provided with a flexible rubber tail fin, which can form a flexible fit between the outer edge of the baffle plate 5 and the borehole wall 1. This allows the baffle plate 5 to have an adaptive confinement capability for irregular borehole wall shapes such as flared or stepped or serrated orifices, thereby improving the integrity of the filling cavity boundary and reducing the risk of grout deviation and leakage.

[0073] Furthermore, the barrier plate 5 is pre-fitted onto the rod 3 and fixed at a predetermined depth from the borehole opening by the limiting pin 13. Preferably, the barrier plate 5 is positioned approximately 5 cm from the inside of the borehole on the tray 10, thus limiting the axial depth of the grout-stopping material filling cavity at the borehole opening to a controllable range, preventing the grout-stopping material from ineffectively filling non-target areas into the borehole, thereby improving material utilization and molding controllability. The limiting member 13 is preferably a limiting pin 13, which can stably limit and fix the barrier plate 5 to the rod 3, and keep the barrier plate 5 in contact with the borehole wall during injection, thereby reducing the risk of axial slippage or eccentric instability of the barrier plate.

[0074] In this embodiment of the invention, the grout-stopping material injection assembly includes at least a grout-stopping material injection hose 8 that passes through the tray 10 and extends into the grout-stopping material filling cavity at the orifice. This hose is used to inject a grout-stopping material mixture into the filling cavity and solidify it to form an orifice grout-stopping sealant, thus cooperating with the orifice sealing assembly to achieve pressure-bearing sealing of the orifice. Wherein:

[0075] For example, the injection port grouting material hose 8 can be a fiber-reinforced hose with an inner diameter of Φ8mm. Its inner end extends into the grouting material filling cavity at the orifice. It is used to inject the mixed grout of components A and B of the orifice grouting material into the orifice section, which is surrounded by irregular gaps such as the borehole wall 1, the rod 3, the orifice grouting material barrier plate 5, and the annular pad 9. This allows the mixed grout to spread, fill, and solidify in situ under confined conditions, ultimately forming an orifice grouting seal that adheres to the borehole wall. Preferably, to enhance the uniformity of grout distribution and the integrity of filling in the irregular gaps at the orifice, the grouting material injection assembly preferably includes two injection port grouting material hoses 8. The two hoses pass through two symmetrical holes in the tray 10 and extend into the orifice grouting material filling cavity. The axial lengths of the two hoses extending into the holes are set to be unequal to form layered grout distribution paths with different injection depths, thereby reducing the risk of weak sealing areas caused by local cavities, air entrapment, and flow deviation.

[0076] Furthermore, the grout injection component can be configured with a two-component feeding and rapid mixing unit, and is connected to the grout injection port hose 8 via a pumping component. This allows for rapid mixing of component A and component B before injection and pumping the mixed grout to the filling cavity, thereby ensuring that the mixed grout completes effective filling and interface bonding within the gelation time window.

[0077] In this embodiment of the invention, a grouting assembly is also provided when grouting operations are required inside the borehole. The grouting assembly includes at least a grouting pipe 7 and an exhaust pipe 4, which pass through the tray 10 and the barrier plate 5 from the outside to the inside and extend into the borehole along the borehole axis. The grouting pipe 7 is used to perform grouting operations inside the borehole after a grout-stopping seal is formed at the borehole opening. The exhaust pipe 4 is used to discharge gas inside the borehole when the grout is injected and serves as an observation port for determining whether the grouting is full. This achieves independent and coordinated operation of the grout-stopping seal for irregular borehole openings and the grouting channel inside the borehole. Specifically, the exhaust pipe 4 is preferably a transparent PVC hose with an outer diameter of Φ8mm and a wall thickness of about 1mm. Its length is equivalent to that of the anchor rod or pipe roof rod. During construction, it is tied and fixed along the rod body 3. It is used to discharge the gas in the gap between the pipe roof (anchor rod) body and the hole wall when the grout is injected, and it also serves as an observation port to determine whether the grouting is full. The grouting pipe 7 is preferably a high-pressure rubber tube with an outer diameter of Φ10mm and a wall thickness of about 1mm. It is used to carry out grouting operations into the hole after a grout stop plug is formed at the hole opening.

[0078] Through the above structural arrangement, a stable sealing system can be built at the borehole opening and a channel guarantee can be provided for subsequent grouting operations. This allows the borehole opening grout sealing and the borehole grouting operations to be spatially isolated from each other and functionally coordinated, thereby improving the stability and engineering applicability of borehole sealing under complex borehole opening conditions.

[0079] Example 3: Construction Method

[0080] Based on the above-described embodiment 2, this embodiment 3 further provides a construction method and working principle for the irregular borehole sealing device for sealing formation boreholes according to the present invention. This device is used to quickly form a pressure-bearing sealing structure at the irregular borehole opening, and on this basis, to complete the grouting operation inside the borehole, achieving sealing and reinforcement of the entire borehole section. Figure 11 As shown, the main steps of this construction method are as follows:

[0081] SS1. Construction Preparation:

[0082] Drill holes along the design direction to the preset depth. After drilling, clean the rock powder, drill cuttings and accumulated water in the hole to avoid the consolidation interface from being mixed and causing discontinuous bonding. Select the appropriate grout-stopping device according to the drilling angle, hole diameter and rod type. Prepare grout-stopping material components A and B, grouting cement slurry and corresponding grouting equipment. At the same time, check the connectivity and sealing of the grout-stopping material hose 8, grouting pipe 7 and vent pipe 4 at the injection port to ensure that the on-site rapid mixing and injection conditions meet the gelation time requirements.

[0083] SS2. Installation of grout-stopping device:

[0084] A solid or hollow rod 3 is axially inserted into the pre-drilled irregular hole to the designed position, with its outer end extending out of the hole to form a connection end and its inner end extending into the hole to form a support reference. A grout-stopping material barrier plate 5 is fitted onto the rod 3 and fixed at a preset depth from the hole opening by a limiting member 13. The outer edge of the barrier plate 5 is adjusted to fit against the hole wall, effectively confining the irregular section of the hole opening. An annular pad 9, a tray 10, and a lock 11 are installed sequentially at the hole opening, and two grout-stopping material hoses 8, an vent pipe 4, and a grouting pipe 7 are connected. The vent pipe 4 is tied along the outside of the rod 3 and connected to the corresponding through hole of the tray 10 to ensure smooth and stable venting and overflow observation. The annular pad 9 forms a sealing interface between the rock surface and the tray 10, and together with the barrier plate 5, the borehole wall 1, and the outer wall of the rod 3, forms a grout-stopping material filling cavity at the hole opening.

[0085] Preferably, when installing the barrier plate 5, a preset axial limiting distance (approximately 5 cm) is maintained between it and the tray 10 to limit the axial depth of the grout-stopping material filling cavity at the orifice; and when connecting the two grout-stopping material hoses 8, the axial lengths of the two hoses extending into the filling cavity are not equal to form a layered grouting path. When the rod body 3 is a hollow structure, a hollow anchor cap 12 can be installed at the outer end of the rod body for sealing during construction.

[0086] SS3. Preparation and injection of grout-stopping material at the orifice:

[0087] Component A (polymethylene polyphenyl polyisocyanate, polyether polyol, and plasticizer) and component B (water glass and tertiary amine catalyst) are rapidly mixed in a designed ratio to form a polyurethane-water glass grouting material mixture. This mixture is then injected through a grouting hose 8 into the gap at the orifice, which is enclosed by the rod 3, the borehole wall 1, the annular gasket 9, and the orifice grouting material barrier plate 5. The injection is controlled to ensure continuous flow, allowing the grout to spread and penetrate thoroughly into the irregular annular gap at the orifice, adhering to the borehole wall until the cavity reaches the preset filling state. This provides the material basis for forming a pressure-bearing grouting plug. The grout solidifies rapidly within tens of seconds, forming a self-adhesive grouting plug that tightly adheres to the irregular borehole wall, achieving a reliable seal at the orifice. As a preferred option, a two-component feeding and rapid mixing unit is adopted, which allows components A and B to be rapidly mixed before injection and then pumped immediately, reducing the risk of premature reaction and curing in the pipeline; during the injection process, the injection flow rate can be adjusted according to the exhaust status and backflow of the exhaust pipe 4, so that the gas in the filling cavity can be smoothly discharged and the air-entrained cavity can be reduced.

[0088] SS4. Curing, locking, and sealing formation:

[0089] During the injection of the grout-stopping material, the gas in the filling cavity is discharged through the micro-gap between the annular pad 9 and the rock surface outside the borehole. After the mixed grout solidifies in situ within the irregular section of the borehole to form a solidified borehole grout-stopping seal and couples with the borehole wall to form a grout-stopping plug, the locking device 11 is tightened to apply axial pressure to the tray 10, so that the annular pad 9 and the rock surface form a sealing interface at the borehole surface, and the borehole grout-stopping seal and the borehole surface sealing interface work together to form a pressure-bearing sealing structure at the borehole, preventing the subsequent grouting pressure from escaping along the borehole. The locking operation is preferably performed after the grout-stopping material has initially set and has basic load-bearing capacity, to avoid the grout being squeezed out or the seal's shape being destroyed due to locking compression.

[0090] SS5. Grouting Operation:

[0091] Once the grout stopper has sufficient strength, i.e., when the grout stopper body in the irregular section of the borehole reaches its design strength and can withstand the grouting pressure, the unobstructedness of the borehole channel and the airtightness of the borehole pressure-bearing sealing structure are checked before grouting is carried out. Specifically, before grouting, the outer end of the vent pipe 4 is kept open and connected to the external detection medium. Under the condition that the grouting pipe 7 is closed or temporarily not started, a preset low-pressure detection gas is slowly applied into the borehole, so that the gas in the borehole is stably discharged through the vent pipe 4 and forms a continuous venting state. At the same time, observe whether there is continuous air leakage, rapid pressure decay, or abnormal backflow at the contact point between the annular pad 9 and the rock surface outside the borehole and around the tray 10. If the test results do not meet the preset judgment conditions, the borehole sealing reliability is restored by retightening the locking device 11 or injecting additional grout stopper material. Grouting is carried out only after the results are confirmed to be qualified.

[0092] After the airtightness test is passed, grout is injected into the depth of the borehole through the grouting pipe 7 or the inner cavity of the hollow rod 3. The gas in the borehole is discharged through the vent pipe 4, which also serves as an observation port for judging the fullness of the grouting. The grouting operation ends when the vent pipe 4 stably returns grout and is full of grout, thus achieving sealing and reinforcement of the entire borehole section. Under medium and low pressure grouting conditions, grouting can be started after curing for 1 minute. Under high pressure grouting conditions, grouting should be started after curing for 3 minutes to ensure the stable pressure resistance of the grout stop plug at the borehole opening.

[0093] Example 4: Pipe Roof Construction

[0094] Based on the above embodiment 3, this embodiment 4 combines Figure 2 The diagram showing the construction status of the pipe shed and the irregular orifice grout-stopping device mentioned in Example 1 indicate that the pipe shed is a pipe shed without the need for sealing the guide wall.

[0095] 1) Construction preparation:

[0096] Drilling: Pipe roof holes were drilled at an outward angle along the designed outline of the tunnel arch using a geological drilling rig. The designed hole diameter was Φ108mm and the depth was 30m. The surrounding rock in the drilling area was strongly weathered granite. After drilling, there was an irregular enlargement of about 5-15mm at the borehole opening and unevenness in the borehole wall.

[0097] 2) Installation of grout-stopping device:

[0098] This working condition employs a device configuration specifically for pipe roofs, mainly including: a pipe roof as the pole 3, an exhaust pipe 4, a grouting pipe 7, and two grouting hoses 8. A Φ89mm hot-rolled seamless steel pipe is used as the pipe roof pole and pushed to the designed hole depth. The two grouting hoses 8, the grouting pipe 7, and the exhaust pipe 4 are connected to the hole-head fixing device, which functions similarly to a tray. The exhaust pipe 4 is tied and fixed along the outer wall of the steel pipe to near the bottom of the hole.

[0099] 3) Preparation and injection of grout-stopping material at the orifice:

[0100] On-site preparation of component A (80 parts by weight): polymethylene polyphenyl polyisocyanate, 20 parts by weight: polyether polyol, 8 parts by weight: plasticizer; and component B (40 parts by weight: sodium silicate with a modulus of 2.3, 1.5 parts by weight: tertiary amine catalyst). Using a two-component grouting pump or a dedicated mixing gun, the two components are rapidly mixed at a volume ratio of A:B of 3:2. The mixed grout is simultaneously injected through two grouting hoses into the irregular annular gap (orifice section) between the pipe roof steel pipe and the borehole wall. The target filling depth is controlled to approximately 5 cm. The grout viscosity is approximately 550 mPa·s, the initial setting time is approximately 25-30 s, the compressive strength reaches 5 MPa in 1 minute, and the strength reaches over 8 MPa in 5 minutes. During curing, there is a slight volume expansion rate of approximately 10%.

[0101] 4) Curing and sealing formation:

[0102] The mixed slurry begins to gel within the orifice gap in about 30 seconds and is completely cured after about 5 minutes, forming a slurry-stopping seal that fits tightly against the irregular orifice wall and has sufficient strength.

[0103] 5) Grouting:

[0104] After the orifice seal has cured for approximately 5 minutes, its strength is confirmed to withstand the grouting pressure. A medium-low pressure extrusion grouting pump is connected to the grouting pipe 7 to inject cement-based grouting material with a water-cement ratio of 0.4 into the deep circumferential gap between the pipe roof steel pipe and the borehole wall. The grouting pressure is maintained stably at 1.0~1.5 MPa (medium-low pressure range), the grout spreads evenly, and there are no leaks at the orifice. Grouting is stopped after the grout flows steadily out of the vent pipe 4, completing the grouting operation for this pipe roof borehole.

[0105] Example 5: Anchor bolt construction (upward or diagonally upward)

[0106] Based on the above embodiment 3, this embodiment 5 combines... Figure 3 , Figure 4 , Figure 5 , Figure 6 This section describes the construction status of upward or obliquely upward anchor bolts for irregular orifice grout sealing devices, using an upward solid anchor bolt as an example. Figure 3 .

[0107] 1) Construction preparation:

[0108] Drilling: A light rock drill was used to drill the anchor bolt holes, with a designed diameter of Φ32mm and a depth of 2.2m. After drilling was completed, high-pressure air was used to thoroughly clean the holes, blowing away rock powder and accumulated water.

[0109] 2) Installation of grout-stopping device:

[0110] This working condition adopts a device configuration for upward solid anchor rods, which mainly includes: rod body 3 (pipe roof or anchor rod), full-length vent pipe 4 (end with vent hole and mesh partition), short grouting pipe 7 (length 5~7cm), two grouting hoses 8, ring pad 9, tray 10 and lock 11.

[0111] Insert the Φ22mm left-handed, unreinforced threaded steel anchor rod into the drilled irregular hole; install the annular gasket 9 and tray 10 in sequence at the hole opening, and connect the two grouting hoses 8, the vent pipe 4, and the grouting pipe 7 to the corresponding interfaces on the tray. Bend the outlet of the vent pipe 4 downwards for easy observation.

[0112] 3) Preparation and injection of grout-stopping material at the orifice:

[0113] On-site preparation of component A by weight: 80 parts of polymethylene polyphenyl polyisocyanate, 20 parts of polyether polyol, and 8 parts of plasticizer; and component B by weight: 40 parts of sodium silicate with a modulus of 2.3 and 1.5 parts of tertiary amine catalyst. Using a two-component injection device, the components A and B were rapidly mixed at a volume ratio of 2:1. The mixed grout was then injected into the annular gap (hole opening section) between the anchor rod and the borehole wall through the grouting hose (8), with a filling depth of approximately 4 cm. The viscosity of the grout was approximately 500 mPa·s, the initial setting time was approximately 15~25 s, the compressive strength reached 8 MPa in 1 minute, and the curing process was accompanied by a micro-expansion rate of approximately 15%.

[0114] 4) Curing, locking, and sealing are formed:

[0115] The grout reacts rapidly after injection, initially setting in about 20 seconds. Once fully cured (about 3-5 minutes) to form a solid grout-stopping seal, the locking device 11 is immediately tightened to apply the designed pre-tightening force to the anchor bolt. This seal replaces the traditional easily detachable cement cartridges or mechanical anchor heads.

[0116] 5) Grouting:

[0117] A medium-low pressure grouting pump is connected to an independently installed grouting pipe 7 to grout the remaining depth of the borehole. Cement mortar with a water-cement ratio of 0.4 is injected. The grouting pressure is controlled at 0.6~1.0 MPa (medium-low pressure range). The grouting process is smooth, the borehole opening is tightly sealed without leakage, and full grouting is achieved throughout the entire borehole section.

[0118] Example 6: Downward Anchor Bolt Construction

[0119] Based on the above embodiment 3, this embodiment 6 combines Figure 9 or Figure 10 This section describes the construction status of the downward anchor bolt for the grout-stopping device, specifically using a downward hollow anchor bolt as an example. Figure 10 .

[0120] 1) Construction preparation

[0121] Drilling: A light rock drill was used to drill the anchor bolt holes, with a designed diameter of Φ32mm and a depth of 2.2m. After drilling was completed, high-pressure air was used to thoroughly clean the holes, blowing away rock powder and accumulated water.

[0122] 2) Installation of grout-stopping device:

[0123] This working condition adopts a device configuration for downward hollow anchor bolts, which mainly includes: rod body 3, short vent pipe 4 (length 5~7cm), grout-stopping material barrier plate at the orifice 5, two grouting hoses 8, ring pad 9, anchor bolt tray 10, anchor bolt lock 11, hollow anchor bolt cap 12 and limit pin 13.

[0124] During installation, a grout-stopping material barrier plate 5 is fitted onto a Φ22 mm left-handed threaded steel anchor rod (hollow anchor rod) and fixed with a limiting piece 13. The tail of the anchor rod is sealed with a hollow anchor rod cap 12. The installed pipe roof anchor rod body is inserted into the drilled irregular hole. A ring pad 9 and a tray 10 are installed in sequence at the hole opening, and the vent pipe 4 and the grout-stopping material hose 8 are connected.

[0125] 3) Preparation and injection of grout-stopping material at the orifice:

[0126] On-site, component A was prepared by weight: 80 parts polymethylene polyphenyl polyisocyanate, 20 parts polyether polyol, and 8 parts plasticizer; component B was prepared by weight: 40 parts sodium silicate with a modulus of 2.3 and 1.5 parts tertiary amine catalyst. Using a two-component injection device, the components A and B were rapidly mixed at a volume ratio of 6:5. The mixed grout was injected into the annular gap (hole opening section) between the anchor rod and the borehole wall through the grouting hose 8, controlling the filling depth to approximately 4 cm. The grout viscosity was approximately 600 mPa·s, the initial setting time was approximately 30-35 s, the compressive strength reached 5 MPa in 1 minute, and a micro-expansion rate of approximately 5% occurred during curing.

[0127] 4) Curing, locking, and sealing are formed:

[0128] The grout reacts rapidly after injection, initially setting in about 30 seconds. Once fully cured (about 3-5 minutes) to form a solid grout-stopping seal, the locking device 11 is immediately tightened to apply the designed pre-tightening force to the anchor bolt. This seal replaces the traditional easily detachable cement cartridges or mechanical anchor heads.

[0129] 5) Grouting:

[0130] A medium-low pressure grouting pump was connected to an independently installed grouting pipe 7 to grout the remaining depth of the borehole. Cement mortar with a water-cement ratio of 0.4 was injected. The grouting pressure was controlled at 0.5~0.8 MPa (medium-low pressure range). The grouting process was smooth, the borehole opening was tightly sealed without leakage, and full grouting of the entire borehole section was achieved.

[0131] In summary, this invention provides a highly flexible and efficient solution for anchoring engineering in complex geological formations and under varying working conditions through the synergistic design and differentiated configuration of "materials-devices-methods". Each embodiment demonstrates a precise technical response to different core requirements:

[0132] Examples 1-3 reveal the core technical principles, modular device structure, and basic construction methods of the present invention, establishing the common advantages of rapid curing, self-adhesive sealing, high early strength, micro-expansion, and high adhesion, providing a reliable technical foundation for adapting to various working conditions.

[0133] Example 4 addresses the challenge of high-pressure sealing of large-diameter pipe roof grouting. By controlling the properties of the grouting material (gelation time 20-25 s, strength ≥6 MPa) and designing the grouting channel in the hollow rod, reliable sealing under grouting pressure of 0.8-1.5 MPa was achieved. This effectively solved the problems of pressure loss and grout leakage caused by irregular diameter expansion of large-diameter pipe roof orifices, ensuring the continuity of the reinforced arch. It is suitable for tunnel pipe roofs and other applications requiring extremely high sealing reliability.

[0134] Example 5 addresses the challenge of significant gravity influence in upward anchor grouting, necessitating the replacement of front-end anchoring. By optimizing the grout mix ratio, it achieves an ultra-short setting time (15~20 s) and high early strength (1 min ≥ 8 MPa), demonstrating good rapid load-bearing and active anchoring capabilities. It effectively solves the problems of easy detachment of traditional front-end anchoring and difficulty in grout sealing in upward boreholes, realizing integrated anchoring and sealing. It is suitable for key parts such as slope reinforcement that resist deformation and require immediate support.

[0135] Example 6 addresses downward anchor grouting. By adjusting the grout viscosity and setting time (initial setting time 30-35 s, compressive strength up to 5 MPa in 1 minute), effective sealing is ensured while also considering workability and backflow prevention. This effectively solves the problems of backflow and unstable orifice sealing caused by the grout's own weight in the downward-facing hole, ensuring grout fullness. It is suitable for scenarios such as foundation pit support where grout backflow needs to be prevented.

[0136] Each embodiment verifies that the grout system, when combined with different device configurations and construction parameters, can form a firmly bonded and durable grout-stopping seal. This invention, through its adjustable material formulation and adaptable device modules, precisely meets various engineering requirements such as "rapid high strength," "high-pressure sealing," "prevention of grout leakage," and "auxiliary anchoring," fully demonstrating its high scientific rigor, engineering applicability, and technical flexibility.

[0137] This invention provides a grout-stopping material, device, and construction method for irregular borehole openings based on polyurethane-water glass, suitable for sealing formation boreholes. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A grout-stopping device for sealing irregular borehole openings in formation drilling, characterized in that, It includes at least a rod body, an orifice sealing assembly, a grout-stopping material confinement assembly, and a grout-stopping material injection assembly, wherein: The rod is a solid or hollow rod, arranged along the borehole axis and passing through the borehole area. Its outer end forms a connecting end for assembly and locking, and its inner end extends into the borehole to form a channel support reference. The orifice sealing assembly includes an annular pad, a tray, and a lock. The annular pad is attached to the outer rock surface of the borehole orifice. The tray is coaxially arranged and has a central through hole for the rod body to pass through. The lock is detachably connected to the outer end of the rod body and applies axial pressure to the tray after the grouting material has cured, so that the annular pad forms an orifice surface sealing interface between the rock surface and the tray. The grout-stopping material confinement assembly includes at least a grout-stopping material barrier plate sleeved on the outer periphery of the rod body and located on the side of the tray facing the hole, and a positioning limiter. The barrier plate is sleeved on the rod body and fixed to the rod body by the positioning limiter, so that the barrier plate, tray, borehole wall, and outer wall of the rod body together enclose the grout-stopping material filling cavity at the orifice and limit the axial filling range of the grout-stopping material in the irregular section of the orifice. The grout-stopping material injection assembly includes at least a grout-stopping material injection hose that passes through the tray and extends into the grout-stopping material filling cavity at the orifice. It is used to inject the grout-stopping material mixture into the filling cavity and solidify it to form an orifice grout-stopping seal, and cooperate with the orifice sealing assembly to achieve pressure-bearing sealing of the orifice.

2. The grout-stopping device for sealing irregular borehole openings in formation drilling according to claim 1, characterized in that, It also includes a grouting assembly, which includes at least a grouting pipe and an exhaust pipe that pass through the tray and the barrier plate from the outside to the inside and extend into the hole along the borehole axis. The grouting pipe is used to perform grouting operations into the hole after a grout-stopping seal is formed at the hole opening. The exhaust pipe is used to discharge gas from the hole when the grout is injected and serves as an observation port for determining whether the grouting is full.

3. The grout-stopping device for sealing irregular borehole openings in formation drilling according to claim 2, characterized in that, The rod body is a pipe roof or an anchor rod. When the rod body is a solid anchor rod or pipe roof, the grouting pipe is set independently relative to the rod body so as to inject grout into the hole after the grout-stopping seal at the orifice has solidified. When the rod body is a hollow anchor rod or pipe roof, the rod body and the grouting pipe are combined into the same component, and the inner cavity of the rod body also serves as the grouting pipe after the grout-stopping seal at the orifice has solidified.

4. The grout-stopping device for sealing irregular borehole openings in formation drilling according to claim 2, characterized in that, The orifice sealing material barrier plate is an annular disc made of ABS engineering plastic. The outer edge of the annular disc is provided with a bendable and deformable rubber tail wing. The inner diameter of the annular disc is adapted to the outer diameter of the rod, and the outer diameter is adjusted according to the size and shape of the drill hole. The rubber tail wing is used to form a flexible fit between the outer edge of the barrier plate and the drill hole wall. Furthermore, the installation position of the barrier plate on the rod body maintains a preset axial limiting distance between it and the tray.

5. The grout-stopping device for sealing irregular borehole openings in formation drilling according to claim 2, characterized in that, The grout-stopping material injection assembly is provided with at least two grout-stopping material hoses at the injection port. The two hoses pass through two symmetrical holes in the tray and extend into the grout-stopping material filling cavity at the injection port. The axial lengths of the two hoses extending into the holes are set to be unequal, so as to form a layered grouting path with different injection depths.

6. The grout-stopping device for sealing irregular borehole openings in formation drilling according to claim 4, characterized in that, The tray is a metal plate component with a central through hole that is coaxial with the rod body, and multiple pipe through holes are evenly arranged around the central through hole along the circumference. When the rod body is a solid anchor rod or pipe roof, there are four pipe through holes, two of which are symmetrically connected to the injection port grouting material hose, and the other two symmetrically connected to the grouting pipe and the vent pipe, respectively. When the rod body is a hollow anchor rod, there are three pipe through holes, two of which are connected to the injection port grouting material hose, and the other hole is connected to the vent pipe.

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