Soft rock tunnel pre-grouting reinforcement treatment method and equipment

Abstract

The invention discloses a soft rock tunnel pre-grouting reinforcement treatment method and equipment, and relates to the technical field of soft rock tunnel grouting reinforcement. Drilling operation is conducted on a tunnel face of a soft rock tunnel in a preset construction area so that a plurality of grouting holes distributed at intervals can be formed in the tunnel face, and a grouting pipe is installed in each grouting hole; and grouting equipment is sequentially communicated with the grouting pipes, grouting operation is conducted on the corresponding grouting holes through the grouting pipes, so that the piston nails in all the grout outlet holes are pushed to be anchored to the hole walls of the grouting holes, and grouting reinforcement operation is completed. Anchoring and connection with a geologic body on a tunnel face are achieved through the arranged grouting pipe and the piston nail installed in the grout outlet hole in the grouting pipe, the contact area between the grouting pipe and the geologic body can be increased through cooperation of the arranged grouting pipe and the piston nail, and the contact area between a grouting reinforcing body and the geologic body is increased; the strength of the geologic body is improved, the deformation trend of the geologic body is reduced, and the grouting reinforcement effect on the soft rock tunnel is improved.

Description

Technical Field

[0001] This invention relates to the field of grouting reinforcement technology for soft rock tunnels, and particularly to a method and equipment for pre-grouting reinforcement of soft rock tunnels. Background Technology

[0002] With the continuous development of modern tunnel engineering, tunnel construction technology under complex geological conditions is also constantly being improved and innovated. Soft rock tunnels, as a special type of tunnel engineering, have long faced significant challenges due to their poor self-stabilizing ability, large deformation, and low strength. To ensure the safety and stability of soft rock tunnel construction, pre-grouting reinforcement technology has gradually become a key technical means in soft rock tunnel construction.

[0003] In existing technologies, grouting reinforcement of soft rock tunnels typically employs hydraulic fracturing or splitting grouting methods. These methods inject high-pressure grout into the surrounding rock, creating fissures. The grout then diffuses, penetrates, and solidifies along these fissures, thereby improving the physical and mechanical properties of the soft rock and enhancing its overall stability and load-bearing capacity. In practical applications, construction workers drill grouting holes at the tunnel face and then inject grout into the surrounding rock using grouting equipment, forming a reinforced zone to enhance tunnel stability.

[0004] However, in actual grouting processes, due to the inherent deformation of soft rock, deformation and intrusion can occur at the tunnel face after pre-grouting, affecting the construction and operational safety of soft rock tunnels. Specifically, soft rock will continue to deform after grouting due to its inherent rheological properties and changes in the surrounding stress environment. This deformation can reduce the effectiveness of the reinforced area and even lead to safety hazards such as tunnel face intrusion and collapse. Summary of the Invention

[0005] The main objective of this invention is to propose a method and equipment for pre-grouting reinforcement of soft rock tunnels. This invention aims to solve the technical problem that, in the actual grouting process, the deformation of the soft rock itself can cause deformation and intrusion at the tunnel face after pre-grouting, thus affecting the construction and operation safety of soft rock tunnels.

[0006] To achieve the above objectives, in a first aspect, the present invention proposes a method for pre-grouting reinforcement of soft rock tunnels, comprising the following steps:

[0007] In the pre-designated construction area, drilling operations are carried out on the working face of the soft rock tunnel to form multiple spaced grouting holes on the working face.

[0008] A grouting pipe is installed in each of the grouting holes; wherein, a plurality of spaced grout outlet holes are formed on the pipe body of the grouting pipe, and one end of each grouting pipe extends out of the grouting hole, the grouting pipe is sealed to the orifice of the grouting hole, and a piston nail is installed in the grout outlet hole.

[0009] The grouting equipment is connected to each of the grouting pipes in sequence, and grouting is performed on the corresponding grouting holes through the grouting pipes, so that the piston nails in all the grout outlet holes are pushed into the hole wall anchored to the grouting hole, thus completing the grouting reinforcement operation.

[0010] In one embodiment, the step of drilling at the face of the soft rock tunnel in a predetermined construction area to form a plurality of spaced grouting holes on the face includes:

[0011] In the pre-designated construction area, drilling operations are carried out on the face of the soft rock tunnel at multiple target angles to form a grouting hole network that is staggered and spaced apart within the geological body corresponding to the face.

[0012] In one embodiment, the step of drilling at multiple target angles at the face of the soft rock tunnel within the preset construction area to form a staggered and spaced grouting hole network within the geological body corresponding to the face of the tunnel includes:

[0013] In the predetermined construction area, geological data information of the tunnel face of the soft rock tunnel is collected; wherein, the geological data information includes crack data of the geological body and daily deformation value of the geological body;

[0014] Based on the geological data, a drilling plan for the grouting holes is determined; wherein, the drilling plan includes the number of grouting holes, the drilling angle of each grouting hole, and the drilling position of each grouting hole;

[0015] According to the drilling plan, for each grouting hole, drilling operations are carried out on the working face of the soft rock tunnel according to the corresponding target angle, so as to form a grouting hole network that is staggered and spaced apart in the geological body corresponding to the working face.

[0016] In one embodiment, the step of setting the drilling plan for the grouting hole based on the geological data information includes:

[0017] Based on the geological data, the fracture development results of the geological body are obtained;

[0018] Based on the crack development results, the drilling scheme for the grouting hole is determined.

[0019] In one embodiment, the step of obtaining the fracture development results of the geological body based on the geological data information includes:

[0020] Based on the geological data, the deformation value of the soft rock of the geological body is obtained;

[0021] Based on the deformation value of the soft rock, the fracture development results of the geological body are obtained.

[0022] In one embodiment, the step of installing a grouting pipe in each of the grouting holes includes:

[0023] For each of the grouting holes, a grouting pipe is installed.

[0024] A sealing material is used to seal the gap between the grouting pipe and the opening of the corresponding grouting hole, so as to complete the installation of one grouting pipe in each grouting hole.

[0025] In one embodiment, the grouting pipe further includes:

[0026] Multiple guide cylinders, the number of which corresponds to the number of grout outlet holes, and each guide cylinder forms an angle with the corresponding grouting pipe; and,

[0027] Multiple connecting ropes are provided, the number of which corresponds to the number of piston nails and they are connected one-to-one, and all the connecting ropes are connected to the corresponding grouting pipes.

[0028] In one embodiment, the step of sequentially connecting the grouting equipment to each of the grouting pipes and performing grouting operations on the corresponding grouting holes through the grouting pipes, so as to push all the piston nails in the grout outlet holes into the hole wall anchored to the grouting hole, thereby completing the grouting reinforcement operation, includes:

[0029] The grouting equipment is connected to each of the grouting pipes in sequence, and pressure grouting is performed on the corresponding grouting holes through the grouting pipes to push the piston nails in all the grout outlet holes into the hole wall anchored to the grouting hole, thereby completing the grouting reinforcement operation.

[0030] In one embodiment, the step of sequentially connecting the grouting equipment to each of the grouting pipes and performing pressure grouting operations on the corresponding grouting holes through the grouting pipes to push all the piston nails in the grout outlet holes into the hole walls anchored to the grouting holes, thereby completing the grouting reinforcement operation, includes:

[0031] The grouting equipment is connected to each of the grouting pipes in sequence, and pressure grouting is performed on the corresponding grouting holes through the grouting pipes so that the piston nails in all the grout outlet holes are pushed into the hole wall anchored to the grouting hole.

[0032] Real-time pressure of the grouting hole is monitored.

[0033] Adjust the grouting pressure of the grouting equipment according to the real-time pressure until the grouting reinforcement operation is completed.

[0034] Based on the same technical concept, in a second aspect, the present invention also proposes a pre-grouting reinforcement treatment device for soft rock tunnels, used to perform the pre-grouting reinforcement treatment method for soft rock tunnels described in the first aspect, so as to perform pre-grouting reinforcement treatment on the soft rock tunnels. The pre-grouting reinforcement treatment device for soft rock tunnels includes:

[0035] A drilling rig, used to drill holes at the face of the soft rock tunnel and form grouting holes at the face of the tunnel;

[0036] Grouting pipe, the grouting pipe being installed inside the grouting hole; and...

[0037] A grouting machine is connected to the grouting pipe to perform grouting operations on the grouting hole through the grouting pipe.

[0038] In use, the technical solution of this invention involves drilling at the face of a soft rock tunnel in a pre-defined construction area to form multiple spaced grouting holes. A grouting pipe is installed in each grouting hole, and the grouting equipment is sequentially connected to each grouting pipe. Grouting is then performed on the corresponding grouting holes through the grouting pipes, pushing the piston pins in all the grout outlet holes into the hole wall anchored to the grouting hole. This completes the grouting reinforcement operation. This invention, in use, utilizes the grouting pipes and the piston pins installed in the grout outlet holes within the grouting pipes to achieve anchoring and connection with the geological body on the tunnel face. Furthermore, the combination of the grouting pipes and piston pins increases the contact area between the grouting pipes and the geological body, thereby increasing the contact surface between the grouting reinforced body and the geological body and improving the reinforcement effect on the geological body. Meanwhile, since the contact surface between the grouting pipe and the geological body is increased by using the grouting pipe and multiple piston nails, the present invention can improve the strength of the geological body by utilizing the cooperation of the grouting pipe and piston nails, thereby reducing the deformation tendency of the geological body and improving the grouting reinforcement effect of soft rock tunnels. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0040] Figure 1 A flowchart of the pre-grouting reinforcement method for soft rock tunnels provided by the present invention;

[0041] Figure 2 This is a flowchart illustrating step S110 of the present invention;

[0042] Figure 3 for Figure 2 The flowchart of step S112 in the example is shown below;

[0043] Figure 4 for Figure 3 The flowchart of step S112a in the example is shown;

[0044] Figure 5 for Figure 1 The flowchart of step S200 in the example is shown;

[0045] Figure 6 This is a flowchart illustrating step S310 of the present invention;

[0046] Figure 7 This is a schematic diagram of the grouting pipe as an example of the present invention;

[0047] Figure 8 This is a schematic diagram of the internal structure of the grouting pipe as an example of the present invention;

[0048] Figure 9 for Figure 8 An enlarged structural diagram of part A in the example;

[0049] Figure 10 This is a schematic diagram of the grouting equipment exemplified by the present invention.

[0050] Reference numerals: 100, grouting pipe; 110, grout outlet; 200, geological body; 210, grouting hole; 120, piston nail; 130, guide cylinder; 140, connecting rope; 10, drilling rig; 30, grouting machine.

[0051] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0053] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0054] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0055] This invention proposes a method and equipment for pre-grouting reinforcement of soft rock tunnels.

[0056] Please see Figures 1 to 10 To facilitate understanding, this method for pre-grouting reinforcement of soft rock tunnels includes the following steps:

[0057] S100. In the preset construction area, drilling operations are carried out on the working face of the soft rock tunnel to form multiple grouting holes spaced apart on the working face.

[0058] Specifically, in this embodiment, when performing grouting operations, drilling operations are first carried out on the tunnel face in a preset construction area (usually the area where the tunnel face of a soft rock tunnel is located).

[0059] During drilling operations, holes can be drilled sequentially on the working face according to pre-set drilling data.

[0060] It should be specifically and clearly stated that, in this embodiment, the example drilling data includes the drilling location of the grouting holes, the number of holes, and the drilling angle and inclination direction of each grouting hole. It can be further clarified that, in this embodiment, the drilling angle of the example grouting holes is preferably 5°–45°.

[0061] More specifically, when drilling grouting holes, the extension direction of the grouting holes should form a mesh-like distribution of holes within the geological body of the working face area, thereby enabling the present invention to obtain a pre-grouting reinforcement structure with a mesh-like structure.

[0062] Currently, when drilling grouting holes, it is also necessary to ensure that the grouting holes formed by the drilling do not interfere with each other, and that there are gaps between all grouting holes.

[0063] S200. Install a grouting pipe in each of the grouting holes.

[0064] The grouting pipe 100 has a plurality of spaced grout outlet holes 110 formed on its body, and one end of each grouting pipe 100 extends out of the grout outlet hole 210. The grouting pipe 100 and the orifice of the grout outlet hole 210 are sealed together, and a piston nail 120 is installed in the grout outlet hole.

[0065] Specifically, in this step, when installing the grouting pipe 100 in each grouting hole 210, the grouting pipe 100 of the corresponding length can be installed in the corresponding grouting hole 210 according to the hole depth of each grouting hole 210. With this installation method, when the piston nail 120 installed in each grouting pipe 100 is performing grouting operation, the grout pressed into the grouting pipe 100 is pushed out from the corresponding grout outlet and anchored into the hole wall of the corresponding grouting hole 210.

[0066] S300. Connect the grouting equipment to each of the grouting pipes in sequence, and perform grouting operations on the corresponding grouting holes through the grouting pipes, so as to push the piston nails in all the grout outlet holes into the hole wall anchored to the grouting hole, and complete the grouting reinforcement operation.

[0067] Specifically, in this step, during grouting operations, the grouting machine 30 can be connected to the grouting pipe 100 first. Then, the grouting machine 30 injects grout into the corresponding grouting hole 210 through the grouting pipe 100. Under the pressure of the grouting machine 30, the grout pushes the piston nail 120 out of the corresponding grout outlet 110 and anchors it into the hole wall of the corresponding grouting hole 210. This ensures that the hole wall between the grouting pipe 100 and the grouting hole 210 forms an anchoring structure, increasing the contact surface and anchoring stability between the grouting pipe 100 and the geological body 200.

[0068] Of course, it can be further clarified that the grout used in this embodiment is preferably cement mortar or acrylate AB grout used for grouting reinforcement.

[0069] In this embodiment, drilling operations are performed on the face of the soft rock tunnel in a predetermined construction area to form multiple spaced grouting holes 210 on the face. A grouting pipe 100 is installed in each grouting hole 210. The grouting equipment is connected to each grouting pipe 100 in sequence, and grouting operations are performed on the corresponding grouting holes 210 through the grouting pipes 100. This pushes the piston nails 120 in all the grout outlet holes into the hole wall anchored to the grouting hole 210, completing the grouting reinforcement operation. This allows the invention to anchor and connect with the geological body 200 on the face by using the grouting pipes 100 and the piston nails 120 installed in the grout outlet holes of the grouting pipes 100. In this way, the invention can increase the contact area between the grouting pipes 100 and the geological body 200 by using the cooperation of the grouting pipes 100 and the piston nails 120. This increases the contact surface between the grouting reinforced body and the geological body 200, thereby improving the reinforcement effect of the geological body 200. Meanwhile, since the contact surface between the grouting pipe 100 and the geological body 200 is increased by the grouting pipe 100 and multiple piston nails 120, the present invention can improve the strength of the geological body 200 by utilizing the cooperation of the grouting pipe 100 and piston nails 120, further reduce the deformation tendency of the geological body 200, and improve the grouting reinforcement effect on soft rock tunnels.

[0070] In one embodiment, step S100 includes:

[0071] S110. In the preset construction area, drilling operations are carried out on the working face of the soft rock tunnel at multiple target angles to form a grouting hole network that is staggered and spaced apart in the geological body corresponding to the working face.

[0072] Specifically, in this step, before commencing construction in the pre-designated construction area, a detailed investigation and evaluation of the geological conditions of the soft rock tunnel is required. Professional geological analysis methods are used to determine the soft rock grade, joint orientation, groundwater distribution, and mechanical properties of the surrounding rock. Based on this investigation data, a targeted borehole layout plan is developed.

[0073] More specifically, in practical operation, taking the construction of a soft rock tunnel face as an example, the surrounding rock of this tunnel face is Class V soft rock, with complex geological conditions and high water content. Therefore, in this embodiment, the detailed operation is carried out through the following steps:

[0074] First, the target angle is determined; multiple borehole locations are set on the working face according to a predetermined plan. The target angle for each borehole is determined based on the shape of the working face and the characteristics of the surrounding rock, preferably ranging from 5° to 45° of upward dip angle, with the drilling direction in the surrounding rock being radial. The setting of the target angle ensures that the grouting material can fully cover the unstable areas of the surrounding rock.

[0075] The grouting holes are distributed in a grid pattern, with one grouting hole at each intersection of the grid. Simultaneously, the drilling density is increased along the principal stress direction, forming a staggered grouting hole network. This structure ensures that the grout material forms a uniform pre-reinforced structure. Taking the specific parameters of this embodiment as an example, the hole spacing is set to 1.5 meters, the longitudinal holes are arranged in a straight line, and the transverse holes are arranged in a quincunx pattern.

[0076] The drilling depth is adjusted according to the hardness of the surrounding rock. The preferred drilling depth is 1.5-2 times the tunnel excavation advance to ensure that the grout can penetrate to the soft rock structure behind the tunnel face. In this embodiment, the drilling depth is determined to be 5 meters.

[0077] In practice, a high-speed rotary drilling rig is used for drilling. The drilling speed is controlled at 0.3-0.6 meters per minute to prevent damage to the borehole wall and borehole collapse caused by excessively fast drilling. Additionally, a φ45mm drill bit is used, and good cooling and lubrication are maintained during the drilling process. High-pressure air or high-pressure water is used to remove drill cuttings.

[0078] After drilling is completed, hole cleaning should be performed immediately. High-pressure water injection or high-pressure airflow is used to remove rock cuttings, mud, and residual water from the hole, ensuring a smooth grouting process. Hole cleaning is a crucial step in ensuring grouting quality, preventing impurities from clogging the grouting pipe and outlet.

[0079] In one embodiment, step S110 includes:

[0080] S111. In the predetermined construction area, collect geological data information of the working face of the soft rock tunnel; wherein, the geological data information includes crack data of the geological body and daily deformation value of the geological body.

[0081] Specifically, the construction team first deployed a series of geological monitoring devices at the tunnel face to collect relevant data on the soft rock geological body in real time. For example, high-precision crack monitoring instruments and deformation displacement sensors were deployed at the tunnel face. The crack monitoring instruments collected the length, width, and distribution direction of cracks in the surrounding rock, while the deformation displacement sensors recorded the displacement of the surrounding rock over a day.

[0082] S112. Based on the geological data, set a drilling plan for the grouting holes; wherein the drilling plan includes the number of grouting holes, the drilling angle of each grouting hole, and the drilling position of each grouting hole.

[0083] Specifically, based on the geological data collected in step S111, the construction team in this embodiment selected areas with developed cracks and areas with large daily deformation values ​​for grouting hole placement. Additional grouting holes were added in areas with concentrated cracks, while the number of grouting holes was appropriately reduced in areas with smaller deformation, in order to minimize construction disturbance and optimize the reinforcement effect.

[0084] S113. According to the drilling scheme, for each grouting hole, drilling operations are carried out on the working face of the soft rock tunnel according to the corresponding target angle, so as to form a grouting hole network that is staggered and spaced apart in the geological body corresponding to the working face.

[0085] During drilling operations, the construction team used a tracked drilling rig to drill holes at the working face according to the established drilling plan. Taking a grouting hole in a specific area as an example, the target angle was selected as 20°, the drill bit length was 5 meters, and the drilling location was in the central area of ​​the working face. During construction, the drilling rig adjusted its direction according to the planned position, slowly drilling into the surrounding rock while maintaining the integrity of the hole wall and ensuring that the drilling depth reached the predetermined parameters. Because the spacing of the grouting holes conformed to the overall drilling plan, the construction team was able to effectively avoid interference problems between the grouting holes. After completing the drilling of all grouting holes, a unified hole cleaning operation was carried out, using high-pressure airflow to blow away debris and accumulated water from the holes, ensuring that the grouting hole walls were clean and smooth, providing a guarantee for subsequent construction stages.

[0086] In one embodiment, step S112 includes:

[0087] S112a. Based on the geological data information, obtain the fracture development results of the geological body.

[0088] Specifically, in this step, the construction team first conducts professional analysis and processing of the geological data collected in step S111. The crack data included in this geological data needs to be classified and statistically analyzed using a data processing system to obtain key information such as the development degree, distribution pattern, and extension direction of the surrounding rock cracks. In practice, technicians input the collected basic data such as crack length, width, direction, and dip angle into geological analysis software, and generate a crack development result report through numerical calculations and graphical modeling.

[0089] The fracture development results specifically include the following aspects: First, a fracture density distribution map, which shows the concentration and distribution range of fractures within the working face area; second, a fracture orientation statistics table, recording the extension direction and dip angle of the main fractures; and third, a fracture connectivity analysis, assessing the interconnection between fractures and the formation of seepage channels. Through the above analysis, technicians can accurately grasp the development characteristics of surrounding rock fractures, providing a scientific basis for the formulation of subsequent drilling plans.

[0090] S112b. Based on the crack development results, set the drilling scheme for the grouting hole.

[0091] Specifically, based on the results of crack development, technicians formulate corresponding drilling plans according to the distribution characteristics and development degree of the cracks. The formulation of the drilling plan follows the principle of "key reinforcement and comprehensive coverage", that is, increasing the number and density of grouting holes in areas with dense cracks, appropriately reducing the arrangement of grouting holes in areas with sparse cracks, and ensuring that the entire working face area is within the coverage of grouting reinforcement.

[0092] For areas with high crack density, the drilling plan sets the grouting hole spacing at 1.2-1.5 meters, and the drilling angle is adjusted according to the crack direction to ensure that the grouting pipes intersect with the main cracks, improving the grout penetration effect. For areas with through cracks, the drilling plan adds dedicated sealing grouting holes, with the drilling angle perpendicular to the crack direction to ensure that the grout can effectively seal the crack channels. For areas with relatively few cracks, the drilling plan sets the grouting hole spacing at 2.0-2.5 meters, using a conventional grid-like arrangement.

[0093] In this embodiment, based on the aforementioned crack development results, the final drilling scheme includes: 35 grouting holes in the central area of ​​the working face, with drilling angles of 15°-25° and drilling depths of 4.5-5.5 meters; 15 grouting holes in the left side area, with drilling angles of 10°-20° and drilling depths of 4.0-5.0 meters; and 8 dedicated sealing grouting holes in the right side area for penetrating cracks, with drilling angles of 30°-40° and drilling depths of 5.5-6.0 meters. The entire drilling scheme comprises a total of 58 grouting holes, forming a comprehensive and focused grouting hole network layout.

[0094] In one embodiment, step S112a includes:

[0095] S11. Based on the geological data, obtain the deformation value of the soft rock of the geological body;

[0096] Specifically, the daily deformation values ​​included in the geological data need to be filtered and processed to obtain daily soft rock deformation values ​​that reflect the true deformation status of the soft rock geological body. In actual operation, technicians summarize the raw data collected by deformation displacement sensors deployed at different locations on the working face, and use the data processing system to eliminate environmental interference factors and measurement errors, and calculate the daily average deformation at each monitoring point.

[0097] The process of obtaining the deformation value of the sun-soft rock is as follows: First, data correction is performed, and temperature compensation and instrument error correction are applied to the original monitoring data; second, data statistics are performed, and the maximum, minimum and average deformation values ​​of each monitoring point are calculated within 24 hours; third, data analysis is performed, and the main direction of deformation and the trend of deformation rate are identified; finally, data integration is performed, and the deformation data of each monitoring point are comprehensively analyzed according to spatial location to obtain the overall distribution map of the sun-soft rock deformation value of the working face.

[0098] S12. Based on the deformation value of the soft rock, obtain the fracture development results of the geological body.

[0099] Specifically, based on the deformation values ​​of the soft rock, technicians established a correlation between deformation and crack development to deduce the crack development results of the geological body. This correlation is based on the mechanical principles of soft rock deformation: when a soft rock geological body is subjected to stress exceeding its tensile strength, tensile cracks will occur at stress concentration points; when subjected to stress exceeding its shear strength, shear cracks will occur on the shear surface. By analyzing the magnitude, direction, and distribution characteristics of the soft rock deformation values, the location, development degree, and extension direction of cracks can be predicted.

[0100] Technicians first established a deformation-stress conversion model, converting the monitored deformation values ​​into corresponding stress values ​​based on the elastic modulus, Poisson's ratio, and other mechanical parameters of the soft rock. Then, stress analysis was used to determine stress concentration areas and principal stress directions. Combined with the tensile and shear strength parameters of the soft rock, they identified areas where cracks had already formed or were about to form. Finally, based on the crack formation mechanism and the structural characteristics of the soft rock, the scale and connectivity of the cracks were predicted.

[0101] In this embodiment, based on the analysis results of the deformation value of the soft rock, the crack development results show that: due to the large deformation value and complex deformation direction in the central area of ​​the face, dense network cracks are expected to be generated, with a crack density of about 10-15 cracks per square meter; the settlement deformation in the top area of ​​the face will lead to the generation of horizontal tensile cracks, with crack lengths possibly reaching 1.5-2.5 meters; the lateral compression in the sidewall area of ​​the face will generate shear cracks at the rock layer interface. These cracks have strong connectivity and may form seepage channels.

[0102] In one embodiment, step S200 includes:

[0103] S210. For each of the grouting holes, install one of the grouting pipes.

[0104] Specifically, in this step, the construction team first selects grouting pipes of the corresponding specifications based on the diameter and depth of each grouting hole, and then installs the grouting pipes one by one. These grouting pipes are typically made of corrosion-resistant materials and can withstand the delivery of high-pressure grout. The outer diameter of each grouting pipe should match the diameter of the grouting hole to ensure a tighter contact between the grouting pipe and the hole wall after installation.

[0105] S220. Use sealing material to seal the gap between the grouting pipe and the opening of the corresponding grouting hole, so as to complete the installation of one grouting pipe in each grouting hole.

[0106] After installing each grouting pipe, the construction team needs to seal the gap between the grouting pipe and the grouting hole opening. This sealing is achieved by filling with a sealing material. The sealing material should be waterproof and pressure-resistant to ensure a long-lasting seal. During the sealing process, the amount of sealing material and the thickness of the sealing layer must be strictly controlled.

[0107] It can be further clarified that, in this embodiment, the grouting pipe 100 of the example also includes a plurality of guide cylinders 130 and a plurality of connecting ropes 140. The number of guide cylinders 130 is the same as that of the grout outlet holes and they are set one-to-one. Each guide cylinder 130 forms an angle with the corresponding grouting pipe 100. The number of connecting ropes 140 is the same as that of the piston nails 120 and they are connected one-to-one. All connecting ropes 140 are connected to the corresponding grouting pipe 100.

[0108] Each guide cylinder 130 is correspondingly installed with a grout outlet 110, ensuring that each grout outlet 110 is equipped with a corresponding guide cylinder 130. The guide cylinder 130 is installed on the outer surface of the grouting pipe 100 and communicates with the corresponding grout outlet 110. The included angle formed between each guide cylinder 130 and the grouting pipe 100 provides directional guidance for the anchoring of the piston nail 120. Specifically, when the grout is pushed out of the grout outlet 110 and the piston nail 120 is pushed out of the grout outlet 110, the piston nail 120, guided by the guide cylinder 130, can enter the wall of the grouting hole 210 at a preset angle.

[0109] The angle is determined based on the distribution direction of the cracks in the geological body 200 and the reinforcement requirements. In practical applications, the angle between the guide cylinder 130 and the grouting pipe 100 is typically set between 5° and 175°. This angle range ensures that the piston nail 120 can effectively anchor into the borehole wall while avoiding interference with adjacent piston nails 120. Guided by the angle of the guide cylinder 130, the anchoring position of the piston nail 120 is more precise and the anchoring depth is more uniform, thereby improving the stability of the overall reinforcement effect.

[0110] The connecting rope 140 is connected one-to-one with the piston nail 120, ensuring that each piston nail 120 is equipped with a corresponding connecting rope 140. One end of the connecting rope 140 is fixedly connected to the piston nail 120, and the other end is connected to the grouting pipe 100, forming a controllable traction relationship. During the grouting reinforcement process, the connecting rope 140 can constrain and control the position of the piston nail 120, preventing the piston nail 120 from penetrating too deeply into the hole wall or deviating from the predetermined position under the action of grout pressure.

[0111] The connecting rope 140 is made of high-strength fiber material, possessing excellent tensile strength and corrosion resistance, and can withstand the pressure during grouting without breaking. The length of the connecting rope 140 is set according to the depth of the grouting hole 210 and the anchoring depth requirement of the piston nail 120, typically 1.2-1.5 times the expected anchoring depth of the piston nail 120. This ensures that the piston nail 120 can be fully anchored into the hole wall, while also allowing for retrieval of the piston nail 120 when necessary via the connecting rope 140.

[0112] The coordinated configuration of the guide cylinder 130 and the connecting rope 140 forms a dual control system for the anchoring process of the piston nail 120. The guide cylinder 130 ensures that the piston nail 120 is anchored into the hole wall in the correct direction by guiding it with its angle, while the connecting rope 140 ensures that the piston nail 120 is anchored at the appropriate depth by constraining its length. This dual control system solves the technical problems of uncontrollable anchoring direction and uneven anchoring depth of the piston nail 120 in traditional grouting reinforcement.

[0113] During the grouting operation, when the grout pushes the piston nail 120 through the grout outlet 110, the piston nail 120 first moves along a preset angle direction under the guidance of the guide cylinder 130, and then is anchored at a suitable depth position under the constraint of the connecting rope 140. Through this structural configuration, the piston nail 120 can be precisely positioned in three-dimensional space, so that the reinforcement effect of the entire grouting hole 210 presents a regular distribution, significantly improving the overall stability of the soft rock tunnel face.

[0114] Of course, it can be further clarified that in this embodiment, the included angle between the guide cylinder 130 and the grouting pipe 100 is set to 5°-175°, so that when the present invention is implemented, the guide cylinder 130 can be used to push out the corresponding piston nail 120 at the corresponding included angle and anchor it to the hole wall of the corresponding grouting hole 210, thereby improving the anchoring stability between the grouting hole 210 and the grouting pipe 100.

[0115] In one embodiment, step S300 includes:

[0116] S310. Connect the grouting equipment to each of the grouting pipes in sequence, and perform pressure grouting on the corresponding grouting holes through the grouting pipes, so as to push the piston nails in all the grout outlet holes into the hole wall anchored to the grouting hole, and complete the grouting reinforcement operation.

[0117] Specifically, in this step, the construction team sequentially connects the grouting equipment and the grouting pipe 100, and performs pressure grouting operations on each grouting hole 210 in sequence. The grouting equipment includes a grouting machine 30 and a pressure monitoring system, whose grouting pressure is adjustable and monitored in real time to ensure that the grout can achieve a diffusion effect within the hole and push the piston nail 120 to anchor to the hole wall. The pressure grouting process of each grouting pipe 100 needs to be flexibly adjusted according to the depth of the grouting hole 210, geological conditions, and crack distribution.

[0118] In one embodiment, step S310 includes:

[0119] S311. Connect the grouting equipment to each of the grouting pipes in sequence, and perform pressure grouting on the corresponding grouting holes through the grouting pipes, so as to push the piston nails in all the grout outlet holes into the hole wall anchored to the grouting hole.

[0120] Specifically, in this step, the construction team establishes connections between the grouting equipment and each grouting pipe according to a predetermined grouting sequence. The grouting equipment includes a high-pressure grouting pump, a grout storage tank, and a piping system, capable of providing stable and adjustable grouting pressure. During the connection process, operators must ensure that the joints between the grouting equipment and the grouting pipes are tightly connected to prevent grout leakage and pressure loss.

[0121] S312. Real-time detection of the real-time pressure of the grouting hole.

[0122] Specifically, during the grouting process, the construction team monitors pressure changes in the grouting holes in real time using pressure sensors installed inside. These pressure sensors accurately measure the pressure inside the grouting holes and transmit the data to the monitoring system in real time. The monitoring system continuously records and analyzes the pressure data, providing data support for subsequent pressure adjustments.

[0123] S313. Adjust the grouting pressure of the grouting equipment according to the real-time pressure until the grouting reinforcement operation is completed.

[0124] Based on the real-time detected pressure data of the grouting hole 210, the operator adjusts the output pressure of the grouting equipment through the control system to maintain the pressure inside the grouting hole 210 within the optimal range. The pressure adjustment follows these principles: when the pressure of the grouting hole 210 is detected to be lower than the set lower limit, the pressure of the grouting equipment is appropriately increased; when the pressure of the grouting hole 210 is detected to be higher than the set upper limit, the pressure of the grouting equipment is appropriately decreased.

[0125] Based on the same technical concept, please refer to Figure 10 Secondly, the present invention also proposes a pre-grouting reinforcement treatment device for soft rock tunnels, used to perform the pre-grouting reinforcement treatment method for soft rock tunnels in the first aspect, so as to carry out pre-grouting reinforcement treatment work on soft rock tunnels. The pre-grouting reinforcement treatment device for soft rock tunnels includes a drilling rig 10, a grouting pipe 100 and a grouting machine 30. The drilling rig 10 is used to drill holes in the tunnel face of the soft rock tunnel and form grouting holes 210 in the tunnel face. The grouting pipe 100 is installed in the grouting hole 210. The grouting machine 30 is connected to the grouting pipe 100 so as to perform grouting work on the grouting hole 210 through the grouting pipe 100.

[0126] Specifically, the drilling rig 10 is used to drill holes at the working face of a soft rock tunnel and form grouting holes 210 at the working face. The drilling rig 10 includes a power head, a drill rod, and a drill bit assembly. The power head provides rotational power, the drill rod is responsible for transmitting torque and pressure, and the drill bit is used to cut the soft rock geological body 200. Combined with the soft rock tunnel pre-grouting reinforcement method exemplified in the first aspect, the drilling rig 10 can efficiently complete the layout of multiple grouting holes 210. The specific operation process is as follows:

[0127] By using the drilling rig 10, it is possible to ensure that the number, depth and direction of the grouting holes 210 meet the design requirements for grouting reinforcement, thereby providing a unified channel for subsequent grouting operations.

[0128] The grouting pipe 100 is installed inside the grouting hole 210 and is used to transport grout and push the piston nail 120 into the hole wall for anchoring. The grouting pipe 100 includes a pipe body, a grout outlet 110 and a sealing structure. The pipe body is used to penetrate the entire grouting hole 210, the grout outlets 110 are distributed at intervals on the pipe body wall, and the sealing structure is installed at the opening of the grouting hole 210.

[0129] The grouting pipe 100's structural configuration effectively enables targeted delivery of grout, ensuring uniform grout distribution within the reinforced area and preventing poor reinforcement results due to uncontrolled grout diffusion.

[0130] The grouting machine 30 is installed in a position connected to the grouting pipe 100 and is used to perform grouting operations on the grouting hole 210 through the grouting pipe 100. The grouting machine 30 includes a power source, a grout tank, a grout pump, a pressure monitoring instrument, and a control system.

[0131] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for pre-grouting reinforcement of soft rock tunnels, characterized in that, Includes the following steps: In the pre-designated construction area, drilling operations are carried out on the working face of the soft rock tunnel to form multiple spaced grouting holes on the working face. A grouting pipe is installed in each of the grouting holes; wherein, a plurality of spaced grout outlet holes are formed on the pipe body of the grouting pipe, and one end of each grouting pipe extends out of the grouting hole, the grouting pipe is sealed to the orifice of the grouting hole, and a piston nail is installed in the grout outlet hole. The grouting equipment is connected to each of the grouting pipes in sequence, and grouting is performed on the corresponding grouting holes through the grouting pipes, so that the piston nails in all the grout outlet holes are pushed into the hole wall anchored to the grouting hole, thus completing the grouting reinforcement operation.

2. The method for pre-grouting reinforcement of soft rock tunnels as described in claim 1, characterized in that, The step of drilling at the face of the soft rock tunnel in a predetermined construction area to form multiple spaced grouting holes on the face includes: In the pre-designated construction area, drilling operations are carried out on the face of the soft rock tunnel at multiple target angles to form a grouting hole network that is staggered and spaced apart within the geological body corresponding to the face.

3. The method for pre-grouting reinforcement of soft rock tunnels as described in claim 2, characterized in that, The step of drilling at multiple target angles at the face of the soft rock tunnel within the preset construction area to form a staggered and spaced grouting hole network within the geological body corresponding to the face of the tunnel includes: In the predetermined construction area, geological data information of the tunnel face of the soft rock tunnel is collected; wherein, the geological data information includes crack data of the geological body and daily deformation value of the geological body; Based on the geological data, a drilling plan for the grouting holes is determined; wherein, the drilling plan includes the number of grouting holes, the drilling angle of each grouting hole, and the drilling position of each grouting hole; According to the drilling plan, for each grouting hole, drilling operations are carried out on the working face of the soft rock tunnel according to the corresponding target angle, so as to form a grouting hole network that is staggered and spaced apart in the geological body corresponding to the working face.

4. The method for pre-grouting reinforcement of soft rock tunnels as described in claim 3, characterized in that, The step of setting the drilling plan for the grouting holes based on the geological data information includes: Based on the geological data, the fracture development results of the geological body are obtained; Based on the crack development results, the drilling scheme for the grouting hole is determined.

5. The method for pre-grouting reinforcement of soft rock tunnels as described in claim 4, characterized in that, The step of obtaining the fracture development results of the geological body based on the geological data information includes: Based on the geological data, the deformation value of the soft rock of the geological body is obtained; Based on the deformation value of the soft rock, the fracture development results of the geological body are obtained.

6. The method for pre-grouting reinforcement of soft rock tunnels as described in any one of claims 1 to 5, characterized in that, The step of installing a grouting pipe in each of the grouting holes includes: For each of the grouting holes, a grouting pipe is installed. A sealing material is used to seal the gap between the grouting pipe and the opening of the corresponding grouting hole, so as to complete the installation of one grouting pipe in each grouting hole.

7. The method for pre-grouting reinforcement of soft rock tunnels as described in claim 6, characterized in that, The grouting pipe also includes: Multiple guide cylinders, the number of which corresponds to the number of grout outlet holes, and each guide cylinder forms an angle with the corresponding grouting pipe; and, Multiple connecting ropes are provided, the number of which corresponds to the number of piston nails and they are connected one-to-one, and all the connecting ropes are connected to the corresponding grouting pipes.

8. The method for pre-grouting reinforcement of soft rock tunnels as described in any one of claims 1 to 5, characterized in that, The step of sequentially connecting the grouting equipment to each of the grouting pipes and performing grouting operations on the corresponding grouting holes through the grouting pipes, so as to push all the piston nails in the grout outlet holes into the hole walls anchored to the grouting holes and complete the grouting reinforcement operation, includes: The grouting equipment is connected to each of the grouting pipes in sequence, and pressure grouting is performed on the corresponding grouting holes through the grouting pipes to push the piston nails in all the grout outlet holes into the hole wall anchored to the grouting hole, thereby completing the grouting reinforcement operation.

9. The method for pre-grouting reinforcement of soft rock tunnels as described in claim 8, characterized in that, The step of sequentially connecting the grouting equipment to each of the grouting pipes and performing pressure grouting through the grouting pipes to the corresponding grouting holes, so as to push all the piston nails in the grouting holes into the hole walls anchored to the grouting holes, and completing the grouting reinforcement operation, includes: The grouting equipment is connected to each of the grouting pipes in sequence, and pressure grouting is performed on the corresponding grouting holes through the grouting pipes so that the piston nails in all the grout outlet holes are pushed into the hole wall anchored to the grouting hole. Real-time pressure of the grouting hole is monitored. Adjust the grouting pressure of the grouting equipment according to the real-time pressure until the grouting reinforcement operation is completed.

10. A pre-grouting reinforcement device for soft rock tunnels, characterized in that, The soft rock tunnel pre-grouting reinforcement treatment equipment is used to perform the soft rock tunnel pre-grouting reinforcement treatment method as described in any one of claims 1 to 9, for performing pre-grouting reinforcement treatment on the soft rock tunnel, and the soft rock tunnel pre-grouting reinforcement treatment equipment includes: A drilling rig, used to drill holes at the face of the soft rock tunnel and form grouting holes at the face of the tunnel; Grouting pipe, the grouting pipe being installed inside the grouting hole; and, A grouting machine is connected to the grouting pipe to perform grouting operations on the grouting hole through the grouting pipe.

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