Drilling and grouting integrated drilling and grouting method

Abstract

The invention provides a drilling and grouting integrated drilling and grouting method which comprises the steps that firstly, the stratum type of a to-be-drilled area is detected, and the stratum type comprises at least one of an underground water-free area, an unpebble area below underground water and a pebble area below the underground water; secondly, according to the target depth of the to-be-drilled area, segmented drilling is conducted on the to-be-drilled area, wall protection treatment is conducted on the hole wall synchronously according to the stratum type so as to prevent the hole wall from collapsing or underground water leakage, and wall protection treatment comprises water injection wall protection or modified water glass injection wall protection; and finally, after the segmented drilling reaches the target depth, retreating grouting is carried out.

Description

Technical Field

[0001] This disclosure relates to the field of integrated drilling and grouting construction in geological engineering, and specifically designs a drilling and grouting method for integrated drilling and grouting. Background Technology

[0002] In geological engineering construction, integrated drilling and grouting technology is often used to reinforce and prevent seepage in complex strata such as tunnels, foundation pits, and slopes. This technology integrates drilling and grouting to achieve rapid and effective stratum treatment. Related techniques typically employ integrated drilling and grouting geological drilling rigs for retreating grouting, which improves construction efficiency to some extent.

[0003] However, in practical applications, the integrated drilling and grouting method still faces a series of technical challenges. First, the wall protection method is relatively simple, failing to provide differentiated treatment based on different geological features. This is particularly problematic in groundwater-bearing or pebble-bearing layers, easily leading to borehole wall collapse and affecting borehole quality and grouting effectiveness. Second, the precision of grout ratio control is insufficient. Conventional single-pump structures struggle to flexibly adjust grout components, resulting in significant ratio deviations that affect grout solidification performance and reinforcement uniformity. Furthermore, the post-grouting pipeline cleaning process has significant drawbacks: traditional cleaning fluids suffer from unsatisfactory cleaning effects, are prone to adverse reactions with the grout, and are costly, hindering large-scale application in engineering projects.

[0004] The aforementioned technical deficiencies severely restrict the reliability and economy of integrated drilling and grouting technology in complex formations. Therefore, optimizing the wall protection process for different formation conditions, achieving precise control of grout ratio, and efficiently and cost-effectively cleaning to prevent grouting pipeline blockage have become critical issues that urgently need to be addressed. Summary of the Invention

[0005] In view of this, in order to solve at least one technical problem in related technologies and other aspects, this disclosure proposes a drilling and grouting integrated drilling method, comprising:

[0006] The geological type of the area to be drilled is detected. The geological type includes at least one of the following: no groundwater area, non-pebble area below groundwater, and pebble area below groundwater.

[0007] Based on the target depth of the drilling area, the drilling area is divided into sections for drilling. According to the stratum type, the borehole wall is simultaneously protected to prevent the borehole wall from collapsing or groundwater from seeping. The protection treatment includes water injection or modified water glass injection.

[0008] After the segmented drilling reaches the target depth, retreat grouting is performed.

[0009] According to embodiments of this disclosure, in the process of protecting the borehole wall: when the stratum is a pebble area below groundwater, the method of protecting the wall is to inject modified water glass to form a gel wall protection layer on the borehole wall of the segmented drilling.

[0010] According to embodiments of this disclosure, the modified water glass wall-protecting solution comprises mixed acid and water glass; wherein,

[0011] The mixed acid consists of citric acid and acetic acid, with a concentration of 4% and a water glass concentration of 20 Baume degrees. The volume ratio of the mixed acid to the water glass is 1:1.

[0012] According to embodiments of this disclosure, in the process of protecting the borehole wall: when the geological formation is in a region without groundwater, segmented drilling is carried out by dry drilling.

[0013] According to embodiments of this disclosure, in the case of wall protection treatment of boreholes: when the stratum type is a non-pebble area below groundwater, the wall protection method is water injection wall protection.

[0014] According to embodiments of this disclosure, the drilling progress of each segmented drilling operation is no more than 40 cm / time.

[0015] According to embodiments of this disclosure, the retreating grouting is a dual-pipe segmented retreating grouting process.

[0016] According to embodiments of this disclosure, the dual-pipe segmented retreat grouting process includes:

[0017] In each grouting process, water-based polyurethane concentrate and curing agent are respectively loaded into the first and second grouting pipes. After the water-based polyurethane concentrate and curing agent are mixed in the drill bit mixer, grouting is performed in a backward grouting manner from the bottom of the borehole upwards; wherein,

[0018] The second grouting pipe is coaxially sleeved outside the first grouting pipe. The first and second grouting pipes are constructed such that one end is connected to the drill bit mixer, and the other end is independently infinitely adjustable by a dual-pump head pneumatic pump. The grouting time for each section is 5 to 10 minutes, and the ratio of water-based polyurethane raw material to curing agent is 1:1.

[0019] According to embodiments of this disclosure, the aforementioned drilling grouting method further includes: after the retraction grouting is completed, cleaning the first grouting pipe with mixed acid; wherein,

[0020] The mixed acid includes citric acid and acetic acid, and the concentration of the mixed acid is 0.1% to 0.5%.

[0021] According to embodiments of this disclosure, the residual rate of aqueous polyurethane stock solution in the first grouting pipe after cleaning is no more than 0.5%.

[0022] According to embodiments of this disclosure, firstly, by pre-detecting the formation type and selecting an appropriate wall protection method, precise wall protection is achieved. This addresses various complex formation conditions, including those without groundwater, those containing groundwater but not in pebble layers, and pebble layers, effectively preventing borehole wall collapse and groundwater leakage during drilling, thus improving borehole quality and construction safety. Secondly, the use of segmented drilling with simultaneous wall protection tightly integrates drilling and wall protection, simplifying the construction process and improving operational efficiency. Finally, after drilling to the target depth, retreating grouting is implemented to ensure that the grout fills the hole evenly and densely from the bottom upwards, contributing to improved overall grouting reinforcement effectiveness and reliability. Attached Figure Description

[0023] Figure 1 This is a flowchart of the drilling and grouting integrated drilling method in this embodiment of the present disclosure. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments.

[0025] The endpoints and any values ​​of the ranges disclosed in this disclosure are not limited to the precise ranges or values, and such ranges or values ​​should be understood to include values ​​close to such ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this disclosure.

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0027] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0028] It should be noted that, unless otherwise defined, the technical or scientific terms used in this disclosure should have the ordinary meaning understood by a person with ordinary skill in the art to which this disclosure pertains. Where the terms "first," "second," etc., are used throughout, they are used only to distinguish similar objects and should not be construed as indicating or implying their relative importance, order of precedence, or implicitly specifying the number of technical features indicated. It should be understood that the data described by "first," "second," etc., can be interchanged where appropriate.

[0029] In this disclosure, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0030] Similarly, to simplify this disclosure and aid in understanding one or more of the various aspects of the disclosure, in the above description of exemplary embodiments of the present disclosure, various features of the present disclosure are sometimes grouped together into a single embodiment or its description. The use of terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refers to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present disclosure. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this disclosure.

[0032] In the process of implementing this disclosure, it was discovered that by systematically improving the wall protection process, proportion control, cleaning system and pipeline structure to form an integrated solution, it is expected to significantly improve the shortcomings of the existing technology and promote the wider application of drilling and injection integrated technology in complex formations.

[0033] Figure 1 This is a flowchart of the drilling and grouting integrated drilling method in this embodiment of the present disclosure.

[0034] This disclosure proposes an integrated drilling and grouting method, such as... Figure 1 As shown, it includes:

[0035] Step S101: Detect the formation type of the area to be drilled. The formation type includes at least one of the following: no groundwater area, non-pebble area below groundwater, and pebble area below groundwater.

[0036] Step S102: According to the target depth of the drilling area, the drilling area is divided into sections for drilling, and the borehole wall is simultaneously protected according to the stratum type to prevent the borehole wall from collapsing or groundwater from seeping. The protection treatment includes water injection or modified water glass injection.

[0037] Step S103: After the segmented drilling reaches the target depth, perform backward grouting.

[0038] According to embodiments of this disclosure, firstly, by pre-detecting the formation type and selecting an appropriate wall protection method, precise wall protection is achieved. This addresses various complex formation conditions, including those without groundwater, those containing groundwater but not in pebble layers, and pebble layers, effectively preventing borehole wall collapse and groundwater leakage during drilling, thus improving borehole quality and construction safety. Secondly, the use of segmented drilling with simultaneous wall protection tightly integrates drilling and wall protection, simplifying the construction process and improving operational efficiency. Finally, after drilling to the target depth, retreating grouting is implemented to ensure that the grout fills the hole evenly and densely from the bottom upwards, contributing to improved overall grouting reinforcement effectiveness and reliability.

[0039] According to an embodiment of this disclosure, in the process of protecting the borehole wall in step S101: when the stratum is a pebble area below groundwater, the method of protecting the wall is to inject modified water glass to form a gel wall protection layer on the borehole wall of the segmented drilling.

[0040] The term "below-groundwater pebble zone" as used in this disclosure refers to an engineering geological section located below the stable groundwater level, where the strata and soil are mainly composed of pebbles (usually referring to round or sub-rounded gravel particles with a diameter greater than 2 mm) and are dominant. This zone is characterized by water saturation, loose structure, and high permeability, making it a typical complex stratum prone to collapse and leakage during drilling operations.

[0041] According to embodiments of this disclosure, in pebble areas below groundwater, where the terrain is complex and unique, modified water glass wall-protecting fluid can rapidly form a dense and continuous gel wall-protecting layer on the borehole wall. This gel layer effectively binds loose and unstable pebble particles, significantly enhancing the integrity and structural strength of the borehole wall, thus directly addressing the core problem of easy borehole collapse in pebble layers. Furthermore, this layer possesses excellent impermeability, effectively preventing groundwater infiltration and erosion, stabilizing the borehole wall while maintaining the working environment within the borehole. This wall-protecting method fundamentally improves the feasibility and borehole quality of drilling in water-bearing pebble layers, providing a stable and reliable working channel for subsequent grouting processes.

[0042] According to embodiments of this disclosure, the modified water glass wall-protecting solution comprises mixed acid and water glass; wherein,

[0043] The mixed acid consists of citric acid and acetic acid, with a concentration of 4% and a water glass concentration of 20 Baume degrees. The volume ratio of the mixed acid to the water glass is 1:1.

[0044] According to embodiments of this disclosure, the modified water glass wall protection liquid formulation with a specific ratio is achieved by mixing a 4% concentration of citric acid and acetic acid mixture with 20 Baume water glass at a 1:1 volume ratio. The mixed acid acts as an activator, which can precisely control the gelation reaction rate and degree of the water glass, enabling it to quickly form a gel wall protection layer with high strength, good toughness and excellent impermeability on the pore walls of the water-bearing pebble layer. The two work synergistically, taking into account the controllability of the reaction, thereby effectively protecting the wall.

[0045] According to an embodiment of this disclosure, in the process of protecting the borehole wall in step S101: when the geological type is a groundwater-free area, segmented drilling is performed by dry drilling.

[0046] As used in this disclosure, the term "groundwater-free area" means that the strata in the area to be drilled are located above the stable groundwater level or within an impermeable layer, and there is no freely flowing groundwater within the drilling depth. The natural water content of the strata in this area is low, and the borehole wall can remain basically stable during drilling, without the need to introduce liquids for wall protection or to resist water pressure.

[0047] According to embodiments of this disclosure, dry drilling is used for segmented drilling in areas without groundwater, completely avoiding the use of water or other protective fluids. This not only saves water resources and material costs but also eliminates the disturbance and potential softening effect of external fluids on the original strata, thus helping to maintain the natural stability of the borehole wall formed by its own structure. Simultaneously, dry drilling avoids the generation of drilling mud, simplifies on-site management, and reduces wastewater treatment procedures.

[0048] According to an embodiment of this disclosure, in the process of protecting the borehole wall in step S101: when the stratum type is a non-pebble area below groundwater, the method of protecting the wall is water injection.

[0049] As used in this disclosure, the term "non-pebble zone below groundwater" refers to a geological section located below the stable groundwater level where the strata and soil are mainly composed of fine-grained or medium-to-coarse-grained soils (such as clay, silt, or sand) other than pebbles. This area is saturated with water, but the soil structure is relatively stable, and the main impact on boreholes comes from groundwater pressure rather than particle loss.

[0050] According to embodiments of this disclosure, in non-pebble areas below groundwater, water is used as the borehole wall protection medium. By continuously injecting clean water during drilling, a stable water pressure can be formed around the borehole wall, effectively balancing the external groundwater pressure and preventing necking or collapse of the borehole wall due to pressure imbalance. Simultaneously, the water flow cools the drill bit, lubricates the borehole wall, and carries away drill cuttings, significantly improving drilling efficiency. Compared to using specialized wall protection slurry, water-based wall protection eliminates the need for complex chemical preparations, greatly reducing material costs and construction complexity.

[0051] According to an embodiment of this disclosure, in step S102, the drilling progress of each segmented drilling is no more than 40 cm / time.

[0052] According to embodiments of this disclosure, strict control over the drilling process ensures short and uniform spacing between each borehole segment, facilitating real-time monitoring of the borehole wall condition and timely implementation of corresponding wall protection measures. This effectively prevents the accumulation of formation disturbance and borehole wall instability that may result from excessively long single drilling runs. Secondly, the short process facilitates close integration with subsequent segmented grouting processes, ensuring that each borehole segment receives immediate wall protection or grouting reinforcement upon completion, significantly improving the continuity of construction and the timeliness of formation treatment. Furthermore, limiting the single-run process reduces the construction risk and equipment load of a single operation, enhancing the adaptability and controllability of drilling in complex and heterogeneous formations.

[0053] According to an embodiment of this disclosure, in step S103, the retreating grouting is a double-pipe segmented retreating grouting process.

[0054] According to embodiments of this disclosure, the dual-pipe segmented retreat grouting process includes:

[0055] In each grouting process, water-based polyurethane concentrate and curing agent are respectively loaded into the first and second grouting pipes. After the water-based polyurethane concentrate and curing agent are mixed in the drill bit mixer, grouting is performed in a backward grouting manner from the bottom of the borehole upwards; wherein,

[0056] The second grouting pipe is coaxially sleeved outside the first grouting pipe. The first and second grouting pipes are constructed such that one end is connected to the drill bit mixer, and the other end is independently steplessly adjustable by a dual-pump head pneumatic pump. The grouting time for each section is 5 to 10 minutes, and the ratio of water-based polyurethane raw material to curing agent is 1:1.

[0057] According to embodiments of this disclosure, a coaxial double-pipe structure is employed to isolate and transport the water-based polyurethane raw material and the curing agent within the pipeline, allowing them to mix instantaneously only within the drill bit mixer. This effectively prevents pipeline blockage caused by premature curing of the grout during transport, ensuring continuous grouting. Furthermore, the thorough mixing before injection into the bottom layer guarantees the reinforcement effect. Secondly, the two grout streams are independently and steplessly adjusted using a dual-pump-head pneumatic pump, facilitating precise dynamic adjustment of the grout volume ratio. This ensures stable grout proportions and sufficient reaction, thereby improving the uniformity and reinforcement strength of the solidified body. Additionally, this independent stepless adjustment method can flexibly adapt to the grouting requirements of different formations by adjusting the grout volume ratio. More specifically, controlling the grouting time adjusts the grouting speed, combined with a backward grouting method from the bottom of the hole upwards, allowing the grout to systematically and fully penetrate and fill formation pores and fractures under pressure, forming a continuous and dense reinforced body, thus improving the reliability and seepage prevention effect of the grouting.

[0058] In some specific embodiments, when the method proposed in this disclosure is applied, the volume ratio error of the waterborne polyurethane raw material to the curing agent is ≤ ±5%.

[0059] In some specific embodiments, the grouting method is to retreat in sections from bottom to top (each section is no more than 40cm) to avoid grout loss.

[0060] In some specific embodiments, a one-way ball check valve is also provided near the drill bit in the first grouting pipe of the double pipe to solve the problem of backflow and pipe blockage in the double pipe.

[0061] According to embodiments of this disclosure, the aforementioned borehole grouting method further includes:

[0062] Step S104: After the retractable grouting is completed, the first grouting pipe is cleaned with mixed acid; wherein,

[0063] The mixed acid includes citric acid and acetic acid, and the concentration of the mixed acid is 0.1% to 0.5%.

[0064] According to embodiments of this disclosure, a weakly acidic cleaning solution can effectively delay the gelation and curing process of residual water-based polyurethane grout in pipelines, extending the cleaning time and thus achieving efficient cleaning. Compared to traditional cleaning agents that are more expensive or have a higher reaction risk, the mixed acid solution used in this disclosure is made from readily available and inexpensive raw materials, and has low corrosivity, making it friendly to pipeline equipment. After cleaning, residues can be largely eliminated, effectively preventing equipment failures and construction interruptions caused by pipeline blockage, and ensuring the reusability of the grouting system and overall construction efficiency.

[0065] In some specific embodiments, hydrogen ions can inhibit the curing reaction of polyurethane, and a low concentration of mixed acid is used to prolong the gelation time of the aqueous polyurethane, allowing residual slurry in the pipeline to be fully dissolved and discharged. More specifically, the correspondence between the mixed acid concentration and the polyurethane gelation time is shown in Table 1 below:

[0066] Table 1

[0067]

[0068] In some specific embodiments, taking 0.3% mixed acid cleaning solution as an example, its cost is only 22 yuan / ton, but its cleaning qualification rate reaches 100%.

[0069] According to embodiments of this disclosure, the residual rate of aqueous polyurethane stock solution in the first grouting pipe after cleaning is no more than 0.5%.

[0070] According to embodiments of this disclosure, the low residue rate after cleaning verifies the effectiveness of the cleaning method described herein. This effectively prevents waterborne polyurethane from solidifying and depositing inside the pipeline, fundamentally avoiding pipeline blockage and equipment failure caused by residues, ensuring the continuity of grouting operations and system reliability, and also ensuring that the grout mix ratio is not contaminated during subsequent grouting.

[0071] In some specific embodiments, the cleaning is performed immediately after grouting is completed.

[0072] In some specific embodiments, compared with traditional drilling and grouting methods, this disclosure reduces the hole collapse rate from ≥20% to 0%, the water-based polyurethane grout ratio error from ≥10% to within ±5%, the grouting pipeline cleaning qualification rate from ≤60% to 100%, the pipe blockage rate from 15% to 0%, and the seepage prevention meets the standards.

[0073] It should be noted that the described embodiments are merely some, not all, of the embodiments disclosed herein. Other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are all within the scope of protection of this disclosure.

[0074] Example 1: Reinforcement Project of a Tunnel in a Gravelly Strata

[0075] The strata contain groundwater and gravel layers. The length of the damaged section of the tunnel is 50m, which requires grouting reinforcement and seepage prevention.

[0076] The construction steps include:

[0077] Using the tunnel defect section as the drilling area, the stratum type was determined to be a non-pebble area below groundwater. Modified water glass wall protection fluid (volume ratio of 4% mixed acid: 20 Baume water glass = 1:1) was injected. Drilling was carried out at 40cm / stroke, and grouting was performed once per stroke.

[0078] After drilling to the target depth, a dual-pump head pneumatic pump is used to adjust the mixing ratio (volume ratio of water-based polyurethane raw material and curing agent = 1:1), and grouting is carried out in stages with backward grouting and a dual-pipe mixing process.

[0079] After grouting is completed, a 0.3% mixed acid cleaning solution is used, and no residue remains in the pipeline after cleaning.

[0080] Effect verification

[0081] Reinforcement effect: After grouting, the formation permeability coefficient decreased from 1×10⁻⁶. -1 cm / s decreased to 5×10 -5 cm / s, seepage prevention meets standards;

[0082] Cost comparison: The cleaning fluid costs only 22 yuan / ton, saving 99.8% compared to traditional hydraulic oil.

[0083] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of this disclosure. It should be understood that the above descriptions are merely specific embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A drilling and grouting integrated method, comprising: The geological type of the area to be drilled is detected, and the geological type includes at least one of the following: no groundwater area, non-pebble area below groundwater, and pebble area below groundwater. According to the target depth of the area to be drilled, the area to be drilled is divided into sections for drilling, and according to the stratum type, the borehole wall is simultaneously protected to prevent the borehole wall from collapsing or groundwater from seeping. The wall protection treatment includes water injection wall protection or modified water glass injection wall protection. After the segmented boreholes reach the target depth, retreat grouting is performed.

2. The drilling and grouting method according to claim 1, wherein, In the process of protecting the borehole wall: when the stratum is a gravel area below groundwater, the method of protecting the wall is to inject modified water glass to form a gel wall protection layer on the borehole wall of the segmented borehole.

3. The drilling and grouting method according to claim 2, wherein, The modified water glass wall-protecting solution comprises mixed acid and water glass; wherein, The mixed acid comprises citric acid and acetic acid, the concentration of the mixed acid is 4%, the concentration of water glass is 20 Baume degrees, and the volume ratio of the mixed acid to water glass is 1:

1.

4. The drilling and grouting method according to claim 1, wherein, In the process of protecting the borehole wall: when the geological formation is a water-free area, the borehole is drilled in sections by dry drilling.

5. The drilling and grouting method according to claim 1, wherein, In the process of protecting the borehole wall: when the stratum type is a non-pebble area below groundwater, the method of wall protection is water injection.

6. The drilling and grouting method according to claim 1, wherein, Each drilling step in the segmented drilling process is no more than 40cm / stroke.

7. The drilling and grouting method according to claim 1, wherein, The retraction grouting is a double-pipe segmented retraction grouting process.

8. The drilling and grouting method according to claim 7, wherein, The dual-pipe segmented retreating grouting process includes: In each grouting process, water-based polyurethane stock solution and curing agent are respectively loaded into the first grouting pipe and the second grouting pipe. After the water-based polyurethane stock solution and the curing agent are mixed in the drill bit mixer, grouting is performed in a backward grouting manner from the bottom of the borehole upwards; wherein, The second grouting pipe is coaxially sleeved outside the first grouting pipe. The first grouting pipe and the second grouting pipe are configured such that one end is connected to the drill bit mixer, and the other end is independently infinitely adjustable by a dual-pump head pneumatic pump. The grouting time for each segment is 5 to 10 minutes. The ratio of the water-based polyurethane raw material to the curing agent is 1:

1.

9. The drilling grouting method according to claim 8 further includes: After the retractable grouting is completed, the first grouting pipe is cleaned with mixed acid; wherein, The mixed acid comprises citric acid and acetic acid, and the concentration of the mixed acid is 0.1% to 0.5%.

10. The drilling grouting method according to claim 9, wherein, The residual rate of water-based polyurethane raw material in the first grouting pipe after cleaning is no more than 0.5%.

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