Advanced grouting reinforcement method

Abstract

This invention discloses a method for pre-grouting reinforcement, comprising: S1, drilling holes in advance around the perimeter of the roadway to be excavated; S2, injecting high-pressure water into the drill holes to open existing closed cracks in the surrounding rock; S3, placing an ultrasonic transducer in the drill hole, the ultrasonic transducer generating ultrasonic waves to vibrate the water in the cracks, while simultaneously injecting grout into drill holes adjacent to the drill hole containing the ultrasonic transducer. This pre-grouting reinforcement method of the present invention improves the grouting range and volume, ensuring the forming quality and stability of the roadway cross-section.

Description

Technical Field

[0001] This invention relates to the technical field of deep earth energy development engineering, specifically to an advanced grouting reinforcement method. Background Technology

[0002] When the tunnel face encounters a fractured zone, the roof and sides of the tunnel are prone to large-scale collapse before anchor bolt and cable support is installed, which seriously affects the quality of the cross-section formation and greatly reduces the support speed and effectiveness.

[0003] In related technologies, in order to ensure the quality and stability of the cross-section forming, the tunnel is generally treated in advance, that is, the tunnel is directly reinforced by grouting. However, since the surrounding rock to be excavated at the tunnel face is in a stress concentration zone, under the action of high stress, the cracks at the cross-section are easily squeezed and closed, resulting in a significant reduction in the crack opening. The grout is difficult to enter the crack, affecting the grouting effect and making it difficult to solve the phenomenon of surrounding rock falling during the tunnel excavation process. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a method for pre-grouting reinforcement.

[0005] The advanced grouting reinforcement method of this invention includes:

[0006] S1. Drill holes ahead of time around the tunnel to be excavated;

[0007] S2. Inject high-pressure water into the borehole to open up the existing closed cracks in the surrounding rock;

[0008] S3. An ultrasonic transducer is placed in the borehole. The ultrasonic transducer generates ultrasonic waves to vibrate the water in the crack. At the same time, grout is injected into the borehole adjacent to the borehole in which the ultrasonic transducer is placed.

[0009] S1 includes: opening a plurality of boreholes at intervals around the perimeter of the tunnel, wherein the distance between adjacent boreholes is greater than 0 and less than or equal to 2m, the diameter of the borehole is greater than or equal to 100mm, and the depth of the borehole is greater than or equal to 50m.

[0010] S2 includes:

[0011] S21. High-pressure water is injected from the bottom of the borehole to the opening of the borehole in a segmented backward manner along the extension direction of the borehole;

[0012] S22. A sealing device is installed in the borehole. The sealing device moves from the bottom of the borehole to the opening of the borehole along the extension direction of the borehole. The sealing device is used to seal high-pressure water in the borehole.

[0013] In step S21, high-pressure water is injected into the borehole every 2m-3m along the extension direction of the borehole.

[0014] Before S3 and after S2, all drill holes except those without the ultrasonic transducer and those prepared for grouting are sealed.

[0015] S3 includes: injecting grout from the bottom of the borehole to the opening of the borehole in a segmented backward manner along the extension direction of the borehole, and the ultrasonic transducer moving in the adjacent borehole from the bottom of the borehole to the opening of the borehole along the extension direction of the borehole and synchronously with the grouting.

[0016] The advanced grouting reinforcement method of this invention involves first drilling holes around the perimeter of the tunnel to be excavated, and then injecting high-pressure water into the holes. This high-pressure water then enters the existing cracks in the surrounding rock through cracks on the inner wall of the holes, thus opening up the existing closed cracks in the surrounding rock. Ultrasonic waves are generated into the high-pressure water in the cracks through an ultrasonic transducer, so that the water in the cracks can maintain continuous vibration and ensure that the cracks are always in an open state. At the same time, grout is injected into adjacent holes to facilitate the entry of grout into the cracks, increase the grouting volume and grouting range, ensure the quality and stability of the tunnel cross-section, and thus improve the tunnel excavation speed and support effect.

[0017] In some embodiments, the high-pressure water contains sand and gravel, which remain within the crack.

[0018] In some embodiments, during S3, slurry is injected into the borehole every 5m-20m along the extension direction of the borehole.

[0019] In some embodiments, the slurry seals the borehole to a depth greater than or equal to 200 mm in the extension direction of the borehole.

[0020] In some embodiments, the pressure of the high-pressure water is greater than or equal to 20 MPa, and the flow rate of the high-pressure water is greater than or equal to 1.5 m³ / s. 3 When grouting into the borehole at a rate of / min, the pressure of the grout is greater than or equal to 40MPa, and the rated flow rate of the grout is greater than or equal to 1m³ / min. 3 / min. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the advanced grouting reinforcement method according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of the grouting process in the advanced grouting reinforcement method according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the movement of the sealing device in the advanced grouting reinforcement method according to an embodiment of the present invention.

[0024] Reference numerals: 1. Borehole; 2. Crack; 3. Ultrasonic transducer; 31. Probe; 4. High-pressure water pump; 5. Hydraulic grouting pump; 51. Grouting pipe; 6. Sealing device; 7. Surrounding rock. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] like Figure 1-3 As shown, the advanced grouting reinforcement method of this invention includes:

[0027] S1. Drill holes 1 ahead of time around the tunnel to be excavated.

[0028] S2. Inject high-pressure water into borehole 1 to open the existing closed cracks 2 in the surrounding rock 7. Specifically, high-pressure water is injected into borehole 1 using a high-pressure water pump 4. The pressure of the high-pressure water is greater than or equal to 20 MPa, and the flow rate of the high-pressure water is greater than or equal to 1.5 m³ / min. 3 / min, which facilitates the entry of the original crack 2 in the surrounding rock 7 through the crack 2 on the inner wall surface of the borehole 1, so as to open up the original closed crack in the surrounding rock 7, and the crack 2 is divergent.

[0029] S3. An ultrasonic transducer 3 is placed in borehole 1. The ultrasonic transducer 3 generates ultrasonic waves to vibrate the water in the crack 2. At the same time, grout is injected into the borehole 1 adjacent to the borehole 1 in which the ultrasonic transducer 3 is placed.

[0030] Specifically, a high-power, large-amplitude ultrasonic transducer 3 is placed inside borehole 1. The ultrasonic transducer 3 can generate high-energy ultrasonic waves, which, based on the water medium within crack 2, allow the water to continuously maintain high-frequency vibration within crack 2, ensuring that crack 2 remains open at all times. Specifically, the transmitter power is greater than or equal to 185KW, and the transducer power density is 32KW.

[0031] Specifically, while the ultrasonic transducer 3 vibrates, a high-pressure, high-flow-rate hydraulic grouting pump 5 is used to inject high-pressure fracturing grout into the borehole 1 adjacent to the borehole 1 into which the ultrasonic transducer 3 is placed, through the grouting pipe 51. The rated grouting pressure of the hydraulic grouting pump 5 is greater than or equal to 40 MPa, and the rated flow rate is greater than or equal to 1 m³ / min. 3 / min, the grouting material selected is a micro-nano high-performance dual-liquid grouting material with a particle size D 95 The grout is less than 5μm, has a bonding strength with the coal and rock mass ≥3.5MPa, a compressive strength of ≥10MPa after 2 hours, and an initial setting time of 30min-1h. This ensures that the grout can further enlarge the crack 2 when it enters the crack, thereby increasing the grouting volume and grouting range.

[0032] The advanced grouting reinforcement method of this invention first drills holes 1 around the perimeter of the roadway to be excavated. High-pressure water is injected into the drill holes 1, allowing it to pass through cracks on the inner wall of the drill holes 1 into the existing cracks in the surrounding rock 7, thereby opening up the existing closed cracks 2 in the surrounding rock 7. Ultrasonic waves are generated into the high-pressure water in the cracks 2 by an ultrasonic transducer 3, keeping the water in the cracks 2 in a continuous vibration state, ensuring that the cracks 2 are always open. At the same time, grout is injected into adjacent drill holes 1, making it easier for the grout to enter the cracks 2, increasing the grouting volume and grouting range, ensuring the cross-sectional forming quality and stability of the roadway, thereby improving the tunneling speed and support effect.

[0033] In some embodiments, the high-pressure water contains sand and gravel, which remain inside the crack 2. Specifically, when the high-pressure water enters the crack 2, it carries the sand and gravel into the crack 2, which supports the crack 2 and ensures the opening of the crack 2, facilitating the entry of grout into the crack 2 during subsequent grouting.

[0034] In some embodiments, S1 includes: opening a plurality of boreholes 1 at intervals around the perimeter of the tunnel, wherein the distance between adjacent boreholes 1 is greater than 0 and less than or equal to 2m; when high-pressure water is injected into one of the boreholes 1 and the high-pressure water is continuously vibrated in the crack 2 by an ultrasonic transducer 3, the crack 2 in the borehole 1 adjacent to one of the boreholes 1 is usually also easily vibrated, thereby ensuring the opening of the crack 2 and extending the duration of crack 2 cracking.

[0035] In some embodiments, the diameter of the borehole 1 is greater than or equal to 100 mm and the depth of the borehole 1 is greater than or equal to 50 m, which facilitates the injection of high-pressure water and slurry into the borehole 1 and the installation of an ultrasonic transducer 3 in the borehole 1, ensuring that the borehole 1 can hold a large amount of slurry and ensuring the amount of slurry injected.

[0036] In some embodiments, S2 includes:

[0037] S21. High-pressure water is injected from the bottom of borehole 1 to the opening of borehole 1 in a segmented backward manner along the extension direction of borehole 1 to ensure the pressure of the high-pressure water injected into borehole 1 each time, so that the high-pressure water can open the cracks 2 in the surrounding rock 7 in a segmented manner, thus ensuring the density and opening of cracks 2.

[0038] S22. A sealing device 6 is installed in the borehole 1. The sealing device 6 moves from the bottom of the borehole 1 to the opening of the borehole 1 along the extension direction of the borehole 1. The sealing device 6 is used to seal the high-pressure water in the borehole 1.

[0039] Specifically, after each injection of high-pressure water into borehole 1, the borehole is sealed by a sealing device 6. The sealing device 6 moves gradually from the bottom of borehole 1 to the opening of borehole 1 along the extension direction of borehole 1 to ensure that the pressure of the high-pressure water can be released on the inner wall surface of borehole 1 and is not easily dissipated, thereby ensuring the effect of the high-pressure water in expanding crack 2.

[0040] In some embodiments, in S21, high-pressure water is injected into the borehole 1 every 2m-3m along the extension direction of the borehole 1. This ensures that the high-pressure water expands the original cracks 2 in the surrounding rock 7 and the uniformity of the cracks 2, thereby ensuring the diffusion range of the grout when injecting grout into the borehole 1, improving the reinforcement and support of the grout on the cross-section of the roadway, and ensuring the forming quality of the cross-section of the roadway.

[0041] In some embodiments, before S3 and after S2, the boreholes 1 without ultrasonic transducers 3 and other boreholes 1 except for the borehole 1 to be grouted are sealed. Specifically, other boreholes 1 can be sealed with cotton yarn or the like to prevent grout from leaking out of other boreholes 1 during grouting.

[0042] In some embodiments, S3 includes: injecting grout in a segmented backward manner from the bottom of the borehole 1 to the opening of the borehole 1 along the extension direction of the borehole 1, so as to ensure the pressure of the grout injected into the borehole 1 each time, so that the grout can fill the crack 2 and ensure the grouting range. At the same time, the ultrasonic transducer 3 has a probe 31, which moves in the adjacent borehole 1 along the extension direction of the borehole 1 from the bottom of the borehole 1 to the opening of the borehole 1 and is synchronized with the grouting, so as to ensure that the grout can more easily enter the crack 2 during grouting.

[0043] In some embodiments, in S3, grout is injected into the borehole 1 every 5m-20m along the extension direction of the borehole 1. Specifically, after each injection of grout into the borehole 1, a sealing device 6 is used to seal the borehole 1. The sealing device 6 moves gradually along the extension direction of the borehole 1 from the bottom of the borehole 1 to the opening of the borehole 1 (e.g., ...). Figure 3(in the direction indicated by the middle arrow) to ensure the pressure of the grout during injection into borehole 1, expand the diffusion range of the grout, and further open the opening and extension length of crack 2, increase the injection volume, and ensure the reinforcement and support of the roadway cross section and the forming quality of the roadway cross section by the grout.

[0044] In some embodiments, the depth to which the grout seals the borehole 1 is greater than or equal to 200 mm in the extension direction of the borehole 1. Specifically, the length of the grout after solidification in the borehole 1 is greater than or equal to 200 mm in the extension direction of the borehole 1, ensuring that the solidified grout reinforces and supports the cross-section of the roadway, improving the forming quality of the cross-section of the roadway, and increasing the tunneling speed and support effect.

[0045] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "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, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0049] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer 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 invention. In this specification, the 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A method for pre-grouting reinforcement, characterized in that, include: S1. Drill holes are made ahead of time around the tunnel to be excavated (1); S2. High-pressure water is injected into the borehole (1) to open up the existing closed cracks (2) in the surrounding rock (7); S3. An ultrasonic transducer (3) is placed in the borehole (1). The ultrasonic transducer (3) generates ultrasonic waves to vibrate the water in the crack (2) that is opened by high-pressure water. At the same time, grout is injected into the borehole (1) adjacent to the borehole (1) in which the ultrasonic transducer (3) is placed. The S1 includes: opening a plurality of boreholes (1) at intervals around the perimeter of the tunnel, wherein the distance between adjacent boreholes (1) is greater than 0 and less than or equal to 2m, the diameter of the borehole (1) is greater than or equal to 100mm, and the depth of the borehole (1) is greater than or equal to 50m. S2 includes: S21. High-pressure water is injected from the bottom of the borehole (1) to the opening of the borehole (1) in a segmented backward manner along the extension direction of the borehole (1); S22. A sealing device (6) is provided in the borehole (1). The sealing device (6) moves from the bottom of the borehole (1) to the opening of the borehole (1) along the extension direction of the borehole (1). The sealing device (6) is used to seal high-pressure water in the borehole (1). In S21, high-pressure water is injected into the borehole (1) every 2m-3m along the extension direction of the borehole (1); Before S3 and after S2, all boreholes (1) except those without the ultrasonic transducer (3) and the borehole (1) prepared for grouting are sealed. The S3 includes: injecting grout from the bottom of the borehole (1) to the opening of the borehole (1) in a segmented backward manner along the extension direction of the borehole (1), and the ultrasonic transducer (3) moving from the bottom of the borehole (1) to the opening of the borehole (1) in an adjacent borehole (1) along the extension direction of the borehole (1) and synchronously with the grouting.

2. The advanced grouting reinforcement method according to claim 1, characterized in that, The high-pressure water contains sand and gravel, which remain in the crack (2).

3. The advanced grouting reinforcement method according to claim 1, characterized in that, In S3, grout is injected into the borehole (1) every 5m-20m along the extension direction of the borehole (1).

4. The advanced grouting reinforcement method according to claim 1, characterized in that, The slurry seals the borehole (1) to a depth greater than or equal to 200 mm in the extension direction of the borehole (1).

5. The advanced grouting reinforcement method according to claim 1, characterized in that, The pressure of the high-pressure water is greater than or equal to 20 MPa, and the flow rate of the high-pressure water is greater than or equal to 1.5 m³ / s. 3 When grouting into the borehole (1) at a pressure greater than or equal to 40 MPa and a rated flow rate greater than or equal to 1 m³ / min, the grout pressure is greater than or equal to 40 MPa and the grout flow rate is greater than or equal to 1 m³ / min. 3 / min.

Images